SET 2
What does a R-B tree offer that a BST doesn't?
A BST can be severely unbalanced and degrade to a linked list.
Moore's Law
1965, # of transistors placed on integrated circuit doubles every two years.
**What is the specified (IETF) max concurrent connections for a client to host?**
2 connections! Chrome now opens 6
2¹¹
2048
Natural: Signs of a HSE HB? (6)
* positive influence, less drama * has good relationships * if you treat them well, they will treat you well * takes compliments WELL, doesn't overcompensate
**Is it okay to use the <body> tag as a container?**
**** yeah -- recommended now
In assembly for x86, ia32 how are sys calls performed?
**syscall** is default way of entering kernel mode on x86-64. This instruction is not available in 32 bit modes of operation on Intel processors. **sysenter** is an instruction most frequently used to invoke system calls in 32 bit modes of operation. It is similar to syscall, a bit more difficult to use though, but that is kernel's concern. **int 0x80** is a legacy way to invoke a system call and should be avoided.
0x3
0011
What is the formal definition of a Regular Expression
1. R₁ U R₂ = R 2. R₁R₂ = R 3. R* 4. a for some a in alphabet ∑ 5. ε for empty string 6. empty set
What numbers have alternatings 1s and 0s?
10, 5
0xD
13
AND Gate?
AND Gate?
What does ASCII stand for?
ASCII abreviated from American Standard Code for Information Interchange, is a character encoding standard (the Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII[2]). ASCII codes represent text in computers, telecommunications equipment, and other devices. Most modern character-encoding schemes are based on ASCII, although they support many additional characters. - 7 BINARY NUMBERS!
How are aborts handled?
Aborts current program.
What is the definition of an "alphabet"?
An alphabet is any finite set of symbols.
OSI Model
Application, Presentation, Session, Transport, Network, Data Physical
David Deida - Way of the Superior Man (Chapter 1 18:31) - A man must feel who he is ___ this life. Sourced in something that never ___ ands has never ___.
Beyond this life. "Ends" and has never "started".
Chrome step over next function call?
CMD '
XD:LOCK, unlock
CMD+L
XD: move all the way to back
CMD+SHIFT+]2
XD: move back
CMD+]
Clear Chrome console?
CMD+k
XD: duplicate
CMd+D or option and click+drag
Full screen switching
CTRL -> <-
**What is content negotiation?**
Content negotiation is a mechanism defined in the HTTP specification that makes it possible to serve different versions of a document (or more generally, a resource representation) at the same URI, so that user agents can specify which version fit their capabilities the best.
What is a DDL?
Data definition language
At what layer of the OSI model does 802.11 operate at?
Data-link layer, layer 2
SQL Joins - inner, left, right, full outer
Default join is inner. drop all things that dont match on both sides left - drop things that dont match on right, keep all elft right - reverse of left outer - everything
Rules of IDs?
Each element can have only one ID Each page can have only one element with that ID
E
Echo (ECK-OH)
EOR
Exclusive Or Rd = Rn And imm
Describe Promise.all(); - How is it settled if given three async tasks?
Given three tasks in an array. The Promise will only resolve when all three are completed. However, when one of them fails, the whole promise rejects.
In adobe XD what makes a symbol a symbol obvious?
Green bounding box
H
Hotel (HOH-TEL)
Shoulder : Three Bones
Humerus, Clavicle (Collarbone), Scapula (Shoulder Blade)
NAND Gate?
Inverter(NOT) + AND
J
Juliet (JEW-LEE-ETT)
**When to use try catch blocks?**
Native objects within JS i.e. JSON.parse
N
November (NO-VEM-BER)
Looks give what
Permission
How to convert NFA to DFA?
Powerset construction
S
Sierra (SEE-AIR-RAH)
What is the height of a binary heap?
The height of a binary heap is always floor(log(n))
What part of the tuple is A → w?
The rule
A language is regular IFF....
There is a finite automaton that recognizes it.
Explain Q = ne
This formula demonstrates that electric charge is quantized, Q is the symbol used to represent charge, while n is a positive or negative integer, and e is the electronic charge, 1.60 x 10-19 Coulombs.
How are unions memory managed in C?
Typically, sizeof or malloc will determine based on the biggest part of the union so that it will have space regardless of which part of the union is chosen.
**What is a socket?**
Visualize a plug socket: An IP address A transport protocol A port number
X
X-ray (ECKS-RAY)
Z
Zulu (ZOO-LOO)
Nice is..
complacent and conciliatory
**DOMContentLoaded vs load**
load event is after image assets (dependent assets have loaded)
Properties of binary to remember
take a number that starts with 1 and a bunch of 0's after it, if you subtract by one, it triggers all the other bits to become 1s that come after. the same way 100 -1 = 99, 1000000_2 -1 = 01111111_2
describe float CSS property
taken from the normal flow and placed along the left or right side of its container, where text and inline elements will wrap around it. An element will shift to containing box until it hits edge or another float element.
C right shifts are determined by...?
type of thing being shifted
What are the five BASIC selectors?
type, class, id, attr, universal
**Why not return undefined?**
use void 0 instead, undefined is rewritable
Protons have what quark composition?
uud
codomain vs range
what can go into a function is the domain. what may come out is the codomain. what actually comes out is the range.
Deida, Natural: What is your thing to give?
your love! your talents!
Working tree
Any directory on your fs which has a repo associated.
B
Bravo (BRAH-VOH)
I
India (IN-DEE-AH)
UCS-2?
Obsolete unicode encoding.
Regression Analysis: Describe all steps of a hypothesis test
https://www3.nd.edu/~rwilliam/stats1/x24.pdf
The Natural: LSD
low sex drive
**RWX permission counts?**
x is 1, write is 2, read is 4
5-Tuple for GNFA and explain it.
Q, Sigma, Delta, q_start, q_accept Note that there can only be ONE accepted and ONE starting state for GNFA. Note how delta is explained.
Protons and neutrons, other hadrons are composed of what?
Quarks
Q
Quebec (KEH-BECK)
CS239 DVIS: RGB vs HSL vs HCL vs HSV?
Red Green Blue HSL - Hue saturation light HCL - Hue Chroma Luminance HSV - Hue saturation value
**What do these HTTP Status Codes indicate?: 200, 301, 302**
200 - OK 301 - Moved permanently 302 - Found/Moved Temporarily
2⁵
32
What is the definition of a string?
A string is a finite sequence of symbols taken from ∑.
What is white labelling
A white label product is a product or service produced by one company (the producer) that other companies (the marketers) rebrand to make it appear as if they had made it.
list.append(x)
Add an item to the end of the list. Equivalent to a[len(a):] = [x].
Why in Haskell, ELM, are parameters and return types NOT different in signature? i.e. div:: Int -> Int -> Int
All functions are considedred curried. All functions take one argument div returns a function. In the example. div 11 returns a function that divides whatever int given by 11. Then we apply that function to a value.
Allopathic Medicine
Allopathic medicine is an expression commonly used by homeopaths and proponents of other forms of alternative medicine to refer to mainstream medical use of pharmacologically active agents or physical interventions to treat or suppress symptoms or pathophysiologic processes of diseases or conditions.
Why is IPv6 separated into two halves of 64 bits?
Allows for flexibility because then we can add MAC address as part of the host bits.
What is the Von Neumann model?
Architecture with instructions in memory i.e. stored program.
Big Endian vs Little Endian
Big Endian Machine that stores the MSB Left to right Little Endian machine stores LSB right to left.
AI: Zoom (Obvious ones)
CMD++ and CMD+-
AI: Zoom to actual size
CMD+1
How is the vertical line test related to functions?
Can test whether or not each x input maps to exactly one y input as a requisite in the functio defintiion.
What is a databse index?
Data structure that improves speed of data retrieval ops at cost of additional writes and storage space to hold the index data structure.
What is the definition of a nondeterministic finite automata?
Described as a 5-tuple What is the one difference between this and DFA?
Pete Hunt "Rethinking Best Practices" : React Components should only contain ___ (2 words)
Display Logic
What is the web's goal?
Display content - this is frequently text. Typography is important. Web design is 95% typography
F
Foxtrot (FOKS-TROT)
What are cores?
Independent execution units tthat can run one program thread at a time in parallel with other cores. Think of a core as equivalent to a thread.
JSX vs JS
JSX allows valid HTML markup. JS rin React requires JS functions that look HTML-like and ouputs HTML ``` return(div(null, MyTitleFactory({title:"propsarecool, color="peru"}))); return (<div><My Title title="props are cool' color="peru"</div>) ```
What is the terminology used to describe Promises that are either rejected or fulfilled?
Settled.
What are the PDUs of each of the first 4 layers of the OSI model?
Layer 1 - Bit, Symbol Layer 2 - Frame Layer 3 - Packet Layer 4 (UDP) - Datagram Layer 4 (TCP) - Segment
P
Papa (PAH-PAH)
list.sort(key=None, reverse=False)
Sort the items of the list in place (the arguments can be used for sort customization, see sorted() for their explanation).
What is Clock SPeed/
Speed of CPU in a sense. Each CPU has a quartz clock and per clock tick the CPU performs instructions measured in cycles per second
What is TLS?
TLS is encrypting payload and not header?
Ayurveda
The central theoretical ideas of Ayurveda developed in the mid-first millennium BCE, and show parallels with Sāṅkhya and Vaiśeṣika philosophies and with Buddhism and Jainism.[27][28] Balance is emphasized, and suppressing natural urges is considered unhealthy and claimed to lead to illness.[19] For example, to suppress sneezing is said to potentially give rise to shoulder pain.[29] However, people are also cautioned to stay within the limits of reasonable balance and measure when following nature's urges.[19] For example, emphasis is placed on moderation of food intake,[30] sleep, and sexual intercourse.[19] Ayurveda names seven basic tissues (dhatu), which are plasma (rasa), blood (rakta), muscles (māmsa), fat (meda), bone (asthi), marrow (majja), and semen (shukra). Like the medicine of classical antiquity, Ayurveda has historically divided bodily substances into five classical elements (Sanskrit [maha]panchabhuta, viz. earth, water, fire, air and ether.[31] There are also twenty gunas (qualities or characteristics) which are considered to be inherent in all substances. These are organized in ten pairs of antonyms: heavy/light, cold/hot, unctuous/dry, dull/sharp, stable/mobile, soft/hard, non-slimy/slimy, smooth/coarse, minute/gross, and viscous/liquid.[32] Ayurveda also names three elemental substances, the doshas (called Vata, Pitta and Kapha), and states that a balance of the doshas results in health, while imbalance results in disease. One Ayurvedic view is that the doshas are balanced when they are equal to each other, while another view is that each human possesses a unique combination of the doshas which define this person's temperament and characteristics. In either case, it says that each person should modulate their behavior or environment to increase or decrease the doshas and maintain their natural state. In medieval taxonomies of the Sanskrit knowledge systems, Ayurveda is assigned a place as a subsidiary Veda (upaveda).[33] Some medicinal plant names from the Atharvaveda and other Vedas can be found in subsequent Ayurveda literature.[34] The earliest recorded theoretical statements about the canonical models of disease in Ayurveda occur in the earliest Buddhist Canon.[35]
What is cohesion in computer science?
The degree to whcih elements of a module belong together.
The default cookie domain is...
The domain that set the cookie originally.
__filename is...
The file name of the current module. This is the resolved absolute path of the current module file. For a main program this is not necessarily the same as the file name used in the command line.
what does initial mean in CSS? (NEEDS REVIEW)
The initial CSS keyword applies the initial value of a property to an element. It is allowed on every CSS property and causes the element for which it is specified to use the initial value of the property. *What is the initial value?* Each property has an initial value, defined in the property's definition table. If the property is not an inherited property, and the cascade does not result in a value, then the specified value of the property is its initial value.
Why must Load instructions stall one cycle even with data forwarding?
The necessary computed value is only available AFTER the MEM stage because in load you load FROM memory TO a register.
What is a derivation in grammars?
The sequence of substitutions to obtain a string.
How do are traps handeled?
They return to the next instruction.
PUT does what?
Updates representation of resource
How do you implement BFS?
Use a queue.
Write through policy?
Write-through: write is done synchronously both to the cache and to the backing store.
Y
Yankee (YANG-KEY)
Correlation Coefficient Range?
[-1,1]
**while (i--) evaluates to what equivalent for loop**
`for (let i = 0; i < arr.length; i++)`
The Natural: Men are logical.. women are...
emotional. dont deprive them of any emotions.
Mission is...
first. always.
Redux: action creators
functions that create actions.
**Does JSON.parse() mutate its arguments?**
nah
STAT 244: In R how do you assign names to a barplot?
names(dataset) <- c ("england", "france", "nomery")
Sex is...
natural
what is the initial value of float?
none
How to convert a Number to binary representation in JS?
number.toString(2); Or function dec2bin(dec){ return (dec >>> 0).toString(2); }
What is the relationship between inputs to a mux and selectors?
where n is inputs and m is selector m = log_2n
How are generators more memory efficient?
Instead of creating a function which returns a list of values, one can write a generator which generates the values on the fly. This means that no list needs to be constructed, meaning that the resulting code is more memory efficient. In this way one can even describe data streams which would simply be too large to fit in memory.
Describe the module category.
Interface that users have to learn Reusable modules of the design Can contain subcomponents Can contain submodules E.g. buttons, forms, listings
**What is a paging file?**
Same thing as swap file, scratch partition, etc. Extend RAM with hard-drive
What is an alphabet?
Set of inputs available to make strings, represented by ∑
Natural(Betaization): where to place dates?
Where it's convenient for YOU.
Alphabet is typically represented by...
∑, ∑⁺, ∑* --> Like in regular expressions, + means 1 or more meaning not including ε (the empty string) whereas * means 0 or more so includes the ε
**How to check if something is a number in JS?**
!isNan(val)
given A →w, read uAv
"uAv yields uwv"
How does NGINX use the reactor pattern?
(VIDEO to come)
Up Quark charge
+2/3e
what does a docker file do? What does a docker-compose.yml file do?
. A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image. Docker Compose (herein referred to as compose) will use the Dockerfile if you add the build command to your project's docker-compose.yml.
___proto__ and .prototype exist where?
.prototype exists for purpose of being constructors - primarily for the "new" keyword. objects have a __proto__ which indicates prototypal chain linkage (dunder proto). __proto__ is the public getter/setter of this .prototype. Object.getPrototypeOf and Object.setPrototypeOf is now recommended though.
**How do you tell jshint to ignore a specific one line of code?**
//jshint ignore: line
What is /dev/zero?
/dev/zero is a special file in Unix-like operating systems that provides as many null characters (ASCII NUL, 0x00) as are read from it.
Prove that red-black trees have a guaranteed height of 2log_2(n+1)
0
0x4
0100
0x5
0101
What is each number in binary prefixed by in ASCII?
011 so 0110000 === 0
Regular Expressions: (0 ∪ ε)1∗, evaluate and justify
01∗ ∪ 1∗ The expression 0 ∪ ε describes the language {0, ε}, so the concatenation operation adds either 0 or ε before every string in 1∗. Epsilons in Regexes almost seem like the quantifier, ?, in regex online.
0000
0x0
2⁵ in hexadecimal
0x20
1000
0x8
Describe red-black trees in 4 points (michael sambol)
1. Node is either red or black 2. The root and the leaves are black ?? 3. If a node is red, then its children are black (red-red property) 4. All paths from a node to its nil descendants contain the same number of black nodes.
**What are the 4 pieces of operation in JS**
1. Stack 2. WebAPIs 3. Task Queue 4. Event Loop
What do threads maintain on its own to allow it to exist and run independently (Name 5)
1. Stack pointer 2. registers 3. scheduling properties - pthread_setschedparam, pthread_getschedparam 4. set of pending and blocked signals - sigpending 5. thread specific data. - pthread_key_create
Characteristics of Charged Particles
1. Two varieties : +, -, like charges repel, unlike harges attract 2. Charge is quantized (see quantization) - Q = ne, e = 1.6*10^-19 3. Electric charge is conserved in a reaction.
Name the 8 man pages and their sections
1. User commands 2. System Calls 3. C Library Functions 4. Devices and Special Files 5. File formats and conventions 6. Games/Screensavers 7. Miscellanea 8.System administration commands and daemons https://en.wikipedia.org/wiki/Man_page
Explain declarative Programming: 1. A program that describes ___ and not ___ 2. Any programming languages that lacks ___ 3. A language with clear correspondence to ___
1. What computation should be performed, not how. 2. Side effects (i.e. referential transparency) 3. Mathematical Logic
React-Router v14: Routes have three props that can be used to define what should be rendered, what are they?
1. component - A React component 2. render - a function that returns a React Element. 3. children - A function that returns a React element.
In a 64-bit floating point (or double) what is the maximum value of the exponent?
11 bits are assigned, thus 1024
0xC
1100
0xE
1110, 14
0xF
1111
0xC
12
What are the private IP address ranges?
192.168.0.0 - 192.168.255.255 (65,536 IP addresses) 172.16.0.0 - 172.31.255.255 (1,048,576 IP addresses) 10.0.0.0 - 10.255.255.255 (16,777,216 IP addresses)
2^7+2^6+2^5+2^4+2^3+2^2+2^1+2^0 ==
255
Size of Floats in C (typically?)
4 Bytes (32-bits) and doubles as 8 Bytes (64-bits). The standard does not formally say: CSTD: There are three floating point types: float, double, and long double. The type double provides at least as much precision as float, and the type long double provides at least as much precision as double. The set of values of the type float is a subset of the set of values of the type double; the set of values of the type double is a subset of the set of values of the type long double. The value representation of floating-point types is implementation-defined. Integral and floating types are collectively called arithmetic types. Specializations of the standard template std::numeric_limits (18.3) shall specify the maximum and minimum values of each arithmetic type for an implementation.
STAT244: seq(5,9) can also be written how in R?
5:9
2⁶
64
2¹³
8192
What is a lower triangular matrix?
A square matrix is called lower triangular if all the entries above the main diagonal are zero. Similarly, a square matrix is called upper triangular if all the entries below the main diagonal are zero. Note that it must be square.
How to convert DFA to GNFA?
Add a new start state with epsilon transition from old start state and new accept state with epsilon transitions going to it.
A
Alpha (AL-FAH)
What is an exception?
An exception is a transfer of control to the OS kernel in response to some event i.e. change in processor state.
**Array.prototype.slice's second argument is...**
An index to slice until but excluding
Why is array access O(1)?
Array access if O(1) because it constitutes to steps. First get the address of the array (beginning) then * num of elements and element size to get that address. (2 steps)
What are conductors?
Atoms and molecules composed. But each has positively charged nucleus and negatively charged electrons around. Negatively charged electrons CAN move around freely between atoms. Charges can go to the edges when extra negative charge is added. Negatives will repel so they want to go to the edges.
What are insulators?
Atoms and molecules composed. But each has positively charged nucleus and negatively charged electrons around. Negatively charged electrons CANNOT move around freely between atoms. You can charge an insulator to uniformly or bunch up one side.
(AB)' where ' is transpose and A and B are matrices
B'A'
What does BASE stand for in NoSQL?
BASE - Basically Available, Soft State, Eventually Consistent
3D Motto
Be decisive, dedicated, disciplined.
ORR
Bitwise OR
ol > li
COMBINATOR: child selector The '>' combinator selects nodes that are direct children of the former specified element.
ol ~ li
COMBINATOR: general sibling selector The '~' combinator selects nodes that follow (not necessarily immediately) the former specified element, if both elements shared the same parent.
Execution time of an instruction formula:
CPI * Time per cycle (clockcycle)
Business of 3 tiers of autonomous systems?
Can get to rest of internet using settlement free agreements (tier 1) Pay to connect to to get but also sell transit? (Tier 2) Don't sell transit (tier 1)
**What are parens in Regex called?**
Capturing groups, can be backreferenced, basically used for grouping as parens do matches per group allowing you to see what subportions of your regex worked
Does a cookie exist after closing your browsers?
Depends on expiration date with "expires/max-age" field. If field is empty, then by default, browser trashes it, else it checks date.
Checklist for web typography: Layout:
Did you... Chunk content with headers, small paragraphs, bulleted lists, sidebars, indenting an entire a paragraph of text, or pull quotes? Limit line length to 350-550 pixels by splitting wide pages into two or more columns? Increase leading to improve readability on longer lines of text and to lighten the overall "color" of a page? Increase spacing between letters or words for emphasis? Use either an indent at the beginning of a paragraph, or double spacing between paragraphs, but not both? Avoid indenting the first paragraph following a header? Use double spacing before headings but single spacing between the heading and the content it introduces?
What is X509
Digital certificate used to verify public key belongs to said user.
Kyle simpson: How does a promise "uninvert the IoC"?
Doesn't use Continuation Passing Style to someone else. Instead says "give me an event listener" and I'll listen for it.
What's the golden rule of rebasing?
Don't do it on public branches.
In Javascript, all Numbers are actually represented as...
Floating numbers
G
Golf (GOLF)
What does ISMP in algorithms stand for?
Interval scheduling maximization problem.
When you read, open, write a file, how is it performed?
It uses a system call (trap) in order to get the kernel to do something.
Osho thinks of a ladder of rungs what are the rungs?
Lowest - Instinct, Middle - Intellect, Highest - Instuition -- They are all primordial attributes.
Describe the serratius anterior
Mucles that originate on surface of 1st to 8th ribs.
What replaces ARP in IPv6?
NDP, neighbor discovery protocol and ICMPv6 and a couple other mechanisms. If a host wants to connect to an IPv6 Network, it just needs to know the routing prefix via NDP.
Injective functions are...
One to One and distinct.
What state does the active opener transition to after sending the first syn?
SYN_SENT
What's the opposite of combinational logic?
Sequential logic.
Why do we need Python sets if we already have Python tuples?
Sets are unordered collections and does not allow duplicates. Tuples are ordered
Surjective functions are...
Surjective means that every "B" has at least one matching "A" (maybe more than one). There won't be a "B" left out. Note the important part here (all codomain vals are mapped)
What does a horizaontal regression line mean?
There is no relationship between the predictor and the response.
U
Uniform (YOU-NEE-FORM)
What is a hard and fast rule for system call error handling?
YOU MUST check the return status of every system-level function. Only exception is the handful of functions that return void. if ((pid = fork()) < 0){ print error. exit(0); }
Who is Jonathan Snook
Yahoo, Shopify, SMACSS
Without using arithmetic ops, how can you find array indices of a related node of a binary heap given a node index?
bit shifts rightshift for division of parent leftshift for left child and right child then add 1 for right
STAT244: Rs vectors are dynamic or fixed?
dynamic
**What does `return false` mean in JQuery?**
event.preventDefault, event.stopPropagation - it is NOT recommended to use return false
The parent of a child of a binary heap represented as an array is at what index (1-index and 0-index)?
floor(k/2); Parent is at floor((k-1)/2);
**How does foreach differ from Map?**
foreach returns undefined. Its use is preferred in side effect functions whereas map returns a transformed array and is pure or should be used purely.
What is the system call used for new processes?
fork()
Linux creates every process using which two system calls?
fork(2), clone(2)
git rm vs git rm--cached vs rm?
git rm = rm && git add <fileremoved> git rm --cached = remove file from index but keep local copy in fs
Natural: Why did you get labelled an a$$hole why when you werent?
got rationalized as an a$$hole due to rejection and opposition to betaization. some women fluctuate between the two sides.
Ways to cook an egg
hard boiled soft boiled hard scrambled soft scrambled sunny side up over easy over medium over hard poached
The Natural: HSE
high self esteem
What styles are affected to node2? <style> ol li { color: blue; } ol, li { font-weight: bold; } ol > li { font-size: 30px; } ol ~ li { color: yellow; } ol + li { color: green } </style> <html> <ol> <ol> <li>node 1</li> <ul> <li>node 2</li> </ul> <li>node 3</li> <li>node 4</li> </ol> </ol> <li>node 5</li> <li>node 6</li> <li>node 7</li> <ul> <li>node 8</li> </ul> </html>
just bold, it isnt affected by the child selector since it is not a direct child.
STAT244: How do you fill a matrix with vector values in R?
matrix(vec,3,4)
R ∪ ε ... (important)
may not equal R. For example, if R = 0, then L(R) = {0} but L(R ∪ ε) = {0, ε}.
What is another term for big endian?
network byte order
for (int i = 0; i < 10; i++) { Console.WriteLine(i); } for (int i = 0; i < 10; ++i) { Console.WriteLine(i); } any difference in output here?
no
WU rules
no drinking no making out within the first 10 mins esp when requested
No write allocate
on a write miss to a cache, write directly to appropriate location in memory instead. Q:: WHAT DO WE DO ON READS?
How to convert a binary number represented as a String to its decimal representation in JS?
parseInt(stringNum,2);
What is the system call used for new threads?
pthread_create()
In set theory what is the vertical bar called?
set-builder notation: {x | x < 2} read "the set of x such that x is less than two". Often a colon ':' is used instead of a vertical bar.
socket()
socket() creates an endpoint for communication and returns a descriptor.
Are Caches built into CPUs?
sometimes! http://superuser.com/questions/196143/where-exactly-l1-l2-and-l3-caches-located-in-computer# As of recently, they're more likely to be on the chip for fastest access (at least L1 is very likely).
Complexity of the 802.11 medium?
the medium is shared (add more)
Codomain v Image/Range?
the range is a subset of the codomain as the codomain is a superset of the range The image (sometimes called the range) of f is the set of all values assumed by f for all possible x; this is the set {f(x) | x ∈ X}. The image of f can be the same set as the codomain or it can be a proper subset of it. It is, in general, smaller than the codomain; it is the whole codomain if and only if f is a surjective function.
**What is /tmp/fs?**
tmpfs is a common name for a temporary file storage facility on many Unix-like operating systems. It is intended to appear as a mounted file system, but stored in volatile memory instead of a persistent storage device.
What is a multiplexer? (MUX)
typically puts out 1 output given a bunch of inputs 2^n and selects one of these inputs as the output
**What is autoprefixer?**
uses CanIUse to find what CSS properties need browser prefixes and adds them for you this is awesome. also can REMOVE prefixes as needed. no need to really care about browser distinctions and can focus on the code.
Explain the duplication problem and its solution
when attempting to do things for specific browsers you end up having to write rules for each browser ``` border-radius: 5px; -moz-border-radius: 5px; -webkit-border-radius: 5px; ``` solution: mixins ``` //default param @mixin rounded-corners-all($size: 5px){ border-radius: $size; -webkit-border-radius: $size; -moz-border-radius: $size; } ```
**How to get path URL of current website?**
window.location.pathname
How is addition implemented in binary?
xor to get sum, use and to get carry and repeat until carry is none.
Regular Expressions: ∅∗, evaluate and justify
{ε}
What is the identity for concatenation of strings?
ε
6
0110
418 status code means?
I'm a teapot
How can you convert a max-heap into a min-heap?
Negate all the values
list.reverse()
Reverse the elements of the list in place.
Smaller transistors do what better?
Switch faster!
Pete Hunt "Rethinking Best Practices" : Djikstra says...
"Our intellectual powers are rather geared to master static relations and our powers to visualize processes evolving in time are relatively poorly developed"
What are the categories of SMACSS?
Base, layout, modules, state, theme
What is a data hazard/dependency?
Data hazards occur when instructions that exhibit data dependence modify data in different stages of a pipeline. Ignoring potential data hazards can result in race conditions (also termed race hazards).
Some context-free languages, however, can be generated only by ambiguous grammars. What are these languages described as?
Inherently ambiguous languages.
Orphan processes are adopted by which process
Init or like process of PID 1(systemd) by reparenting.
What does Gerard Berry say on Reactive Programming?
It is convenient to distinguish roughly between three kinds of computer programs. Transformational programs compute results from a given set of inputs; typical examples are compilers or numerical computation programs. Interactive programs interact at their own speed with users or with other programs; from a user point of view, a time-sharing system is interactive. Reactive programs also maintain a continuous interaction with their environment, but at a speed which is determined by the environment, not the program itself. Interactive programs work at their own pace and mostly deal with communication, while reactive programs only work in respond to external demands and mostly deal with accurate interrupt handling. Real-time programs are usually reactive. However, there are reactive programs that are not usually considered as being real-time, such as protocols, system drivers, or man-machine interface handlers.
What's julienne?
Julienne, or allumette, is a culinary knife cut in which the food item is cut into long thin strips, similar to matchstick.[1] Common items to be julienned are carrots for carrots julienne, celery for céléris remoulade or potatoes for Julienne Fries.
Natural: What is LMD?
Last minute doubt
ELM: FEM - How do I create local variables in ELM?
Let... in.. construct
The Internet is a ___ of ___?
Network of networks? communicated by an EGP like BGP and IGP
Has moore's law stopped?
No, not really. Rather we're at a power wall with dennard scaling i.e. the ability to drop voltage and current due to leakage are static power losses cuasing thermal runway.
When asked to draw a DFA for a prescribed language, can the DFA accept strings that are NOT members of that language?
No. DFA's are exclusive to that prescribed language.
CS239 DVIS: What are Steven's levels of measurements?
Nominal, ordinal, interval, ratio
Python Tuples
Orderd, immutable, fixed size, heterogeneous
What is $$ in Bash?
PID of current shell
Level Order Traversal datastructure used?
Queue
R ∪ ∅ is... (important)
R Adding the empty language to any other language will not change it.
list.count(x)
Return the number of times x appears in the list.
What are the 3 options for restarting after a system call?
Return to I_Current, Return to I_Next, Abort.
list.index(x[, start[, end]])
Return zero-based index in the list of the first item whose value is x. Raises a ValueError if there is no such item. The optional arguments start and end are interpreted as in the slice notation and are used to limit the search to a particular subsequence of the list. The returned index is computed relative to the beginning of the full sequence rather than the start argument.
Difference between set-cookie vs. Doucment.cookie?
Set-cookie is an HTTP Header of request. This request generated with document.cookie
What does execve() do?
System call (trap)
What does fork() do?
System call (trap) (TODO)
Tali Garsiel Vimeo Video:
TODO
Pete Hunt "Rethinking Best Practices" : "Templates separate ___ and not ____"
Technologies concerns
Pete Hunt "Rethinking Best Practices" : Accessibility of ___, power of ___ (2 words total)
Templates, Javascript
D3 FEM: How do you d3.select(<nonexistingel> and add elements?
Use the Enter-Append method.
**If you have an inline-element, inline-block, or inline-whatever, whats the way to horizontally center that element within the block?**
Text-align: center the parent block element
When thinking about inversions what does it really imply?
That an inverse multiplied by its inverse is the identity or unit.
Who sends the first syn in a 3-way handshake?
The active opener.
Information architecture (IA)
The art and science of organising and labeling websites, intranets, online communities and software to support usability.
What are bijective functions?
Those that are both surjective and injective. The function is bijective (one-to-one and onto or one-to-one correspondence) if every element of the codomain is mapped to by exactly one element of the domain. so no two xs mapping to a single y no unused codomain values Bijection is a bijective function.
Limit to number of fonts for websites?
Three at most but dangerous. Two is okay. One is good.
Commutative property
Two elements x and y of a set S are said to be commutative under a binary operation * if they satisfy x*y=y*x. (1) Real numbers are commutative under addition x+y=y+x (2) and multiplication
David Deida - Way of the Superior Man (Chapter 1 07:48) - What are the three stages of masculine development?
Until fairly recently, modern roles for men and women were fixed and separated. Men were supposed to go out and earn money. Women were supposed to stay home and take care of the kids. Men often manipulated their women through physical and financial dominance and threat. Women often manipulated their men through emotional and sexual strokes and stabs. The typical and extreme caricatures of this previous time are the macho jerk and the submissive housewife. If you are reading this book, you have probably outgrown this first stage of sexual identity. Or at least you can smile about it. Next came (and is still coming) a stage in which men and women both sought to balance their inner masculine and feminine energies toward "50/50," becoming more like one another. For instance, in the United States in the 1960's, men began to emphasize their inner feminine. They learned to go with the flow. They let go of their rigid, one-dimensional masculine stance and embraced long hair, colorful clothes, nature, music, and a more carefree and sensual lifestyle, all means of embellishing or magnifying radiance, energy, and the abundant force of life—magnifying the feminine. Meanwhile, many women were doing just the opposite. They were magnifying their inner masculine, which, at the level of human character, appears as direction, or clarity of purpose, and vision. Women gained financial and political independence. They strengthened their careers, focused more on personal long term goals, went to school in increasing numbers for advanced degrees, and learned to be more assertive in their needs and desires. Chances are, if you are reading this book, you are more balanced than your parents were. If you are a woman, you are probably more independent and assertive than your mother was. If you are a man, you are probably more emotionally expressive and open-minded than your father was. Or, at least such qualities seem acceptable to you, even if you don't express them yourself. Remember, not that many years ago, a man who got his hair styled or a woman who wore a business suit was often considered suspect. It was a good thing, as time progressed, for men to embrace their inner feminine and women to embrace their inner masculine. They became less fragmented and more whole in the process. They became less dependent on each other: men could, indeed, change diapers, and women were completely capable of emptying the mouse traps. Macho men became more loose and feeling. Submissive housewives became more independent and directed. In terms of social roles, men and women became more similar. This was an improvement for everyone. But this 50/50 stage is only a second and intermediate stage of growth for men and women, not an endpoint. Side effects of xv THE WAY OF THE SUPERIOR MAN this trend toward sexual similarity can be seen as a major cause of today's unhappiness in intimacy. The trend toward 50/50 has resulted in economic and social equality, but also in sexual neutrality. Bank accounts are balancing while passions are fizzling out. Men are less macho while sex and violence continue to increase on TV and in the movies. Women are more in control of their economic destiny while they go in increasing numbers to therapists and doctors to cope with stress related disease. Why is this happening? In my workshops and consultations I hear independent and successful women complaining that many of today's men have become "wimps," too weak and ambiguous to really trust. Sensitive and affectionate men are complaining that many of today's women have become "ballbusters," too hardened and emotionally guarded to fully embrace. Is this the ultimate expression of human sexual wisdom and evolution, or is there another step to take? To answer these questions, we need to understand the nature of sexual passion and spiritual openness. Sexual attraction is based on sexual polarity, which is the force of passion that arcs between masculine and feminine poles. All natural forces flow between two poles. The north and south poles of the earth create a force of magnetism. The positive and negative poles of your electrical outlet or car battery create an electrical flow. In the same way, masculine and feminine poles between people create the flow of sexual feeling. This is sexual polarity.
What is a vector?
Vector: a quantity with more than one element (more than one piece of information). (Euclidean Vector) If the vector represents a real three dimensional (or 2d) thing, you could also say it has magnitude and direction.
How do we know what to do given an exception?
We look into an exception table that holds the appropriate code.
Define Range, Codomain, Domain
What can go into a function is the domain. What can come out of a function is called the codomain. What actually comes out of a function is the range.
Soft scrambled egg recipe
Whip your eggs (I add a little milk) in a separate bowl. Heat your pan no higher than medium, grease it, pour the eggs in, then stay close with a spatula. Turn and fold them repeatedly while they cook. Use the spatula to prevent them from spreading out, especially up the sides of the pan; when they spread too thin, they'll over-cook quickly. I usually fold them until they no longer look runny, but still look wet (i.e. light is reflecting in them). Have your plate ready so you can remove them from heat immediately. They're perfect on buttered toast with salt and pepper; try adding slices of cheese or sauteed kale.
W
Whisky (WISS-KEY)
**How to create JS stacks and queues?**
arrays are stacks! use push and pop arrays are queues if you use push and shift
What's a composite function?
basically composing functions using other functions f: x -> y g: y -> z h: x -> z via g o f
(cA)' where ' is transpose and c is a scalar is...
cA'. The transpose of a scalar is still the same scalar.
**What is the hostname and host in http://example.org:8888/foo/bar?q=baz#bang**
hostname: example.org host: example.org:8888 [Link](http://bl.ocks.org/abernier/3070589)
What are complementary colors?
colors directly opposite each other in the color spectrum, such as red and green or blue and orange, that when combined in the right proportions, produce white light.
Donald knuth says, "Subroutines are special cases of ..."
coroutines
Neutrons have what quark composition?
ddu
How to promote modular scale using SASS?
declare a base font size and a modular scale. then calculate the rest of the fonts and vertical rhythms via functions. $font-size: 15px; $modular-scale: 1.333 h2 { font-size: $font-size * $modular-scale; }
In VanillaJS, write code that sets name-value expiry date and path
document.cookie = " ppkcookie1=testcookie; expires=Thu, 2 Aug 2001 20:47:11 UTC; path=/"
**How does Array.prototype.fill work?**
first val is value to fill with second is start index, third is end index (included)
What are HTML attributes?
https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes Elements in HTML have attributes; these are additional values that configure the elements or adjust their behavior in various ways to meet the criteria the users want. class, id are examples of attributes. these are different from elements.
react elements are what functional concept?
immutable
position: inherit
inherits whatever positioning from parent. note that the position property does NOT cascade.
what elements wrap around a float?
inline and text.
top shortcuts (k,q,r,s,P,M,l,t,m,B,u) run with (-b, -n)
k - kill q - quit r - renice s - change update rate P - sort by CPU usage M - sort by memory usage l - toggle load average t - toggle task display
sort() can take in a key and reverse values. explain
key is f() of an arg that is used to extrract a comparison key from each element.
what values of float are available?
left right none
Array.prototype.reduce callback params?
prev, curr, idx, array - initial val as second param to reduce
Explain the calculation problem and its solution
things are typically related to one size. that is putting things into a modular scale is natural. by having calculations within the CSS u can reflect this semantically. css doesnt allow calculations to exist within the actual code. @functions, @if, @else, etc. being able to calculate within the code.
Name 4 different ISAs
x86, MIPS, ARM, SPARC
What is a word?
"Word size" refers to the number of bits processed by a computer's CPU in one go (these days, typically 32 bits or 64 bits). Data bus size, instruction size, address size are usually multiples of the word size.
What is the syntax for string interpolation in SASS?
#{$variable}col2{ }
**Element.innerHTML is equivalent to what in JQuery?**
$("selector").html("replacedHTML");
What are the differences between a DFA and an NFA?
*Steve:* An NFA can have states that transition to 0 or more states. Additionally, it can have epsilon transitions. Sipser: The difference between a deterministic finite automaton, abbreviated DFA, and a nondeterministic finite automaton, abbreviated NFA, is immediately ap- parent. First, every state of a DFA always has exactly one exiting transition arrow for each symbol in the alphabet. The NFA shown in Figure 1.27 violates that rule. State q1 has one exiting arrow for 0, but it has two for 1; q2 has one arrow for 0, but it has none for 1. In an NFA, a state may have zero, one, or many exiting arrows for each alphabet symbol. Second, in a DFA, labels on the transition arrows are symbols from the alpha- bet. This NFA has an arrow with the label ε. In general, an NFA may have arrows labeled with members of the alphabet or ε. Zero, one, or many arrows may exit from each state with the label ε. *MathOverflow:* Each input to a DFA or NFA affects the state of the automaton: if it was in state qq immediately before the input, either it will be in some state q′q′ after the input, or the input will cause it to choke. (Note that q′q′ may be the same as qq.) Suppose that we have an automaton in a state qq. The difference in behavior between a DFA and an NFA is this: If it's a DFA, each possible input determines the resulting state q′q′ uniquely. Every input causes a state change, and the new state is completely determined by the input. Moreover, the automaton can change state only after reading an input. If it's an NFA, some inputs may allow a choice of resulting states, and some may cause the automaton to choke, because there is no new state corresponding to that input. Moreover, the automaton may be constructed so that it can change state to some new state q′q′ without reading any input at all. As a consequence of this difference in behavior, DFA's and NFA's differ in another very important respect. If you start a DFA in its initial state and input some word ww, the state qq in which the DFA ends up is completely determined by ww: inputting ww to the DFA will always cause it to end up in state qq. This is what is meant by calling it deterministic. If you start an NFA in its initial state and input some word ww, there may be several possible states in which it can end up, since some of the inputs along the way may have allowed a choice of state changes. Consequently, you can't predict from ww alone in exactly which state the automaton will finish; this is what is meant by calling it nondeterministic. (And it's actually a little worse than I've indicated, since an NFA is also allowed to have more than one initial state.) Finally, these differences affect how we determine what words are accepted (or recognized) by an automaton. If it's a DFA, we know that each word completely determines the final state of the automaton, and we say that the word is accepted if that state is an acceptor state. If it's an NFA, there might be several possible final states that could result from reading a given word; as long as at least one of them is an acceptor state, we say that the automaton accepts the word. What I've described informally is the view of an NFA that makes it look most like a DFA and that I think best explains why it's called nondeterministic. There is, however, another way of looking at NFAs: it's also possible to think of an NFA as being in multiple states at once, as if it were making all possible choices at each input. If you think of it in those terms, you can say that it accepts a word provided that at least one of the states in which it ends up after reading that word is an acceptor state. This point of view is perhaps most useful for understanding the algorithm used to turn an NFA into an equivalent DFA.
How are the bits of a double in ieee754 divided?
1 sign bit, 11 Exponent bits, 52 mantissa or fraction bits
**How to search by date after 2016 on Google?**
1. 2016..2016 or 2016..2017
What is inside an ethernet frame header?
1. 64-bit Preamble - used for synchronization purposes 2. Dest MAC 3. Src MAC (optional 802.1Q) here 4. Type of Payload (EtherType) 5. Payload 6. 32-bit CRC
What are the steps towards drawing out an FA?
1. Identify requirements as states and draw em. 2. Add transitions. 3. Indicate starting and final states.
0xB
11
0xD
1101
A grammar consists of...
A collection of *substitution rules*
'\x41\x42\x43', '\x61\x62\x63'
ABC, abc
What are the three types of cache misses?
Cold miss, Conflict miss, capacity miss.
What are some examples of exceptions?
Divide by 0, arithmetic overflow, page fault, I/O request completes, CTRL-C
What are priority queues?
In a priority queue, an element with high priority is served before an element with low priority. Every element has a priority assigned to it.
What is a socket?
The combination of an IP address and a port.
**What is the gradient?**
The gradient is a vector that represents direction of greatest increase for multivariate functions.
The Natural: HSD
high sex drive
What is another term for little endian?
host byte order
Describe three parts of delts
medial - side, anterior - front, posterior - back
0x0
0000
0xC
1100, 12
0xD
1101, 13
Explain _.curry (lodash)
Basically transforams a function into a curry-able function.
The process steps
Empathize - learn about your customers and feel their painpoints, Define - user personas, construct a point of view based on insights, Ideate - brainstorm many possible solutions, Prototype (build a representation of your solution), Test (Go back to Ideate)
Give some examples of arity
Nullary, unary, binary, ternary, n-ary
**The promise's .then returns what?**
On the actual implementation: It returns a Promise!
AI: Hand tool
Spacebar
**How to convert unicode num to string? **
String.fromCharCode(num);
Basic Multilingual Plane (BMP):
0x0000-0xFFFF - pretty much what most people use.
0001
0x1
2⁴ in hexadecimal
0x10
0010
0x2
0011
0x3
0100
0x4
0101
0x5
0110
0x6
0111
0x7
1010
0xA
1011
0xB
1101
0xD
1110
0xE
0x8
1000
8
1000
0x9
1001
10
1010
0xA
1010, 10
0xB
1011
0xB
1011, 11
0xE
1110
0xF
1111, 15
2⁷
128
32767
2¹⁵-1 => size of two bytes in twos complement - i.e. MAX SHORT INT
128 in powers of 2
2⁷
256
2⁸ ASCII unsigned char char (-128 to 127)
Absolute vs Relative Positioning?
Both "relative" and "absolute" positioning are really relative, just with different framework. "Absolute" positioning is relative to the position of another, enclosing element. "Relative" positioning is relative to the position that the element itself would have without positioning.
**How do you center an element horizontally and vertically using transform?**
Follow the child absolute method: Make parent positioned. Make child top: 50%, left:50% position: absolute on the child transform: translate(-50%, -50%) the child
CSS Specificity
Furtherdown wins when equal. !important you want to be as specific as it makes sense to be
In compilers/lexical analysis, what is the definition of "token"?
A token is a structure representing a lexeme that explicitly indicates its categorization for the purpose of parsing.[3] A category of tokens is what in linguistics might be called a part-of-speech. Examples of token categories may include "identifier" and "integer literal", although the set of token categories differ in different programming languages. The process of forming tokens from an input stream of characters is called tokenization.
Storyboard
A tool inspired by the filmmaking industry, where a visual sequence of events is used to capture a user's interactions with a product. Depending on the audience, it may be an extremely rough sketch, purely for crystallising your own ideas.
In automaton theory, what are the arguments to a transition function and describe what a transition function does.
A transition function takes a state and a word ∨ string. A transition function is what takes a machine in ONE state to another. The important note here is that the inputs are solely that, inputs, the labels on the arrows are words.
When to use CMYK vs RGB?
if you're ever doing something for a screen, use RGB, if you doing something for print, use CMYK. With RGB you start with black - the absence of light; with CMYK you start with white paper. Some people prefer to use RGB always then convert to CMYK, adjust as necessary and use CMYK for final output.
What are rendering engines, how do -moz- -webkit relate?
A web browser engine (sometimes called layout engine or rendering engine) is a program that renders marked up content (such as HTML, XML, image files, etc.) and formatting information (such as CSS, XSL, etc.). e.g. webkit, gecko, blink, etc some css styles require you to specify which rendering engine you are targeting
**Base-line, leading, vs line-height**
Base-line where letters sit and descenders extend Leading - typically distance between base-lines Line-height CSS - font-size + top margin + bottom margin (not css-wise margins)
2³²
4,294,967,296
What do pty and tty mean in Unix?
"tty" originally meant "teletype" and "pty" means "pseudo-teletype". In UNIX, /dev/tty* is any device that acts like a "teletype", ie, terminal. (Called teletype because that's what we had for terminals in those benighted days.) A pty is a pseudotty, a device entry that acts like a terminal to the process reading and writing there, but managed by something else. They first appeared (as I recall) for X Windows and screen and the like, where you needed something that acted ilke a terminal but could be used from another program http://stackoverflow.com/questions/4426280/what-do-pty-and-tty-mean
**A Git Pull is composed of two smaller Git functions that are what?**
$git fetch $git merge
What are the components of the MVVM pattern?
* Model * View-Model - The view model is an abastraction of the view, exposing public properties and commands. The VM, has no controller, instead has a binder. * View * Binder - Declarative Data and command binding are implicit in the MVVM pattern
How does a 2-bit predictor, 2-bit counter work?
00 Strong Not Taken 01 - Weak Not Taken 10 - Weak Taken 11 - Strong Taken
0x1
0001
Status code sets 1xx 2xx 3xx 4xx 5xx?
1 is informational, 2 - successful, 3 - reidrection, 4 - client error, 5 - server error
2¹⁶
65536
What is a Lemma?
A short theorem used in proving a larger theorem. basically a supporting theorem
Describe three parts of deltoid.
Anterior: front Medial: Side Rear(Posterior): Back
When you run $ls with systems in a bash shell who is the default parent of that process?
Bash via fork() and execvp() or similar.
Give four spine parts from top to bottom
Cervical Thoracic Lumbar Sacral
The Natural: Girl goes OUT of her way to help you is a ....
Comfort test
SI Unit of charge is...
Coulomb - represented as C and frequently converted to e 1C = 6.24150975·1018e or 1e = 1.60217646·10-19C
What should each state have in DFA's with regards to transitions?
Each state should have a transition for every possible input.
Explain the stable marriage problem
Given two sets of objects, each with a priority list of the other set, can we create a stable set, where stable is defined as there not existing a "better match". Formally stable: There is an element A of the first matched set which prefers some given element B of the second matched set over the element to which A is already matched, and B also prefers A over the element to which B is already matched.
**How does gradient descent play with the cost function?**
Gradient descent is just an algorithm to find the minimum of a function, in this case the cost function. It helps us find the optimal parameters that we use to minimize our cost and get best accuracy
Characteristics of a Natural
He's a leader. - show her your world. be decisive. Humor - Humor about her (not put on pedestal). Humor at his own cost. (doesn't take himself too seriously) - always fun to hang out with Social - always befriending people. - doesn't judge people He has goals - knows what he wants and busy. Unapologetic - has a set of values and acts according to them. Might not be perfect, but perfect with himself. (Don't be apologetic about sex) He's always in a good mood - (True confidence) - Despite adversity -- knows that no matter what happens, he's going to be just fine. Sees the world as easy. Believe you're gonna be fine no matter what. He has his OWN reality - He plays by his own rules. Doesn't make other people's opinions his rules. He has a strong frame. Think Nietzsche camel vs lion/baby.
-> Why would you want generators over a function that returns an array?
However, instead of building an array containing all the values and returning them all at once, a generator yields the values one at a time, which requires less memory and allows the caller to get started processing the first few values immediately. In short, a generator looks likea function but behaves like an iterator.
Examples of buffering?
I/O streams, keyboard strokes - spooling (Spooling is a combination of buffering and queueing.)
React-Routerv14: Router components expect how many children?
One... typically <App>
What are two ways a STA can associate w/ AP in 802.11?
Probes or Beacon Frames
What is a matrix?
Put simply, a rectangular array of numbers, symbols, expressions. They often represent linear transformations.
What is Quantization?
Quantization is the procedure of constraining something from a continuous set of values (such as the real numbers) to a relatively small discrete set (such as the integers).
R ◦ ε is... (important)
R Joining the empty string to any string will not change it.
What are the three types of data dependencies/hazards?
RAW - Flow WAR - Anti WAW - Output
RGB
RGB is a additive, projected light color system. All colors begin with black "darkness", to which different color "lights" are added to produce visible colors. RGB "maxes" at white, which is the equivalent of having all "lights" on at full brightness (red, green, blue). Most screens (computer, phone, media player, television, ect) are RGB (e-ink screens being an exception), the pixels have little subpixels that just show red, green or blue. Expressed from 0-255 for a total of 256 per color.
What is RPC?
RPC (Remote Procedure Call) is like calling a function, only that it is present remotely on a different server as a service. A service exposes many such functions/procedure to its client. And client requires some way to know what are the functions/procedures exposed by this service and what are their parameters.
What are the secondary colours?
Red+yellow = orange Yellow+Blue = Green Blue+red = purple
Why is double precision a misnomer?
Refers to a type of floating-point number that has more precision (that is, more digits to the right of the decimal point) than a single-precision number. The term double precision is something of a misnomer because the precision is not really double. The word double derives from the fact that a double-precision number uses twice as many bits as a regular floating-point number. For example, if a single-precision number requires 32 bits, its double-precision counterpart will be 64 bits long.
What's Object.prototype.constructor?
Returns a reference to the Object function that created the instance's prototype.
Pete Hunt "Rethinking Best Practices" : "Components are ___, ___, ___" (3 terms 4 words)
Reusable, composable, unit testable
**Matrices are column first or row first?**
Row first 100x2 matrix = 100 rows, 2 columns
Explain Saturation in color theory (scott naismith)
Saturation is the purity of a hue. Desaturation is NOT adding gray. Colorfulness or saturation in colorimetry and color theory refers to the perceived intensity of a specific color. Colorfulness is the visual sensation according to which the perceived color of an area appears to be more or less chromatic.(wiki)
Kyle Simpson mentions a trick to handle promises that don't resolve within a time, how do you do this?
SetTimeout, Promise.Race
Python Data Structures
Sets, Lists, Tuples, Dictionaries
How can a BST degrade to a linked list?
Severely unbalanced linked list in one direction. All left or right subtrees.
How can a BST degrade to a linked list?
Severly unbalanced linked list in one direction. All left or right subtrees.
DVIS: Give 6 examples of Visual Encoding by Jacques Bertin:
Shape, Size, Color Hue, Color Value, Color Intensity, Texture
Drop a woman if...
She doesn't engage in your mission, vision, purpose.
Describe the "Black Depth" of a red-black tree
The # of black nodes from root to a node is the node's "black depth"
What is the difference between a half-adder and a full-adder?
The half adder takes in two inputs and puts out two outputs. The two inputs are the operands to sum up. The full-adder takes in three inputs where the third input is the carry in signal. Two outputs as well.
When an asynchronous exception occurs - what does the handler do?
The handler returns to the next instruction. e.g. timer interrupt (goes off every few ms). i/o interrupt from external device.
Body copy height guideline?
The line height refers to the vertical space between lines of text. For body text, 150% of the font size is a good starting point. Use a longer line height with a wider measure and vice versa. This is because the longer the measure, the harder it will be for the eye to navigate to the start of the next line. Using a longer line height negates this effect.
AI: Global swatches
This allows you to specify colors on multiple vector elements and then change their colors all at the same time instead of changing each individual color.
U+0048 U+0065 U+006C U+006C U+006F.
This is Unicode. Each of these are code points. The U+ means "Unicode" and the numbers are hexadecimal.
**What is logistic regression used for?**
This is a good algorithm to predict the output of a categorical variable.
How do you convert CFGs into DFAs? Why would you do so?
This is a good way to convert a CFG into a regular language.
David Deida - Way of the Superior Man (Chapter 1 24:58) - "What do I need to do or become to die complete?"
This is the question David Deida says is another way to put the idea of deepest purpose.
V
Victor (VIK-TAH)
What happens when you mix complementary colors together?
When you mix two opposites together anywhere on the Color Wheel, the result becomes increasingly neutral.
Can DFA's have no final states?
Yes, that would only indicate that the empty language is what is recognized.
**All data is typically transmitted as what type?**
as a string! serialize/deserialize
STAT244: How do you create a vector of 4,7,9 in R?
c(4,7,9)
**:not selector**
don't affect elements with these selectors
Write the height and size functions for a red-black tree represented as: type Color = R | B type Tree = E | T Color Tree Int Tree
height t = case t of E -> 0 T _ l _ r -> 1 + max (height l) (height r) size t = case t of E -> 0 T _ l _ r -> 1 + size l + size r
What is happening here?
if MEM[PC] == ADD Rd, Rn, Rm GPR[Rd] ← GPR[Rn] + GPR[Rm] PC ← PC + 4
Linux Permissions: rwx rwx rwx applies to who in what order?
owner(u), group(g), all users(a)
How to convert a binary number to its decimal representation in JS?
parseInt(number, 2);
48 is representative of...
start of numbers in ASCII
Regular Expressions: (ΣΣΣ)∗ evaluate
{w| the length of w is a multiple of 3}
Regular Expressions: 1∗∅, evaluate and justify
∅ If A and B are sets, we define A∘B={ab:a∈A and b∈B} A∘B={ab:a∈Aand b∈B}. If B=∅, there are no objects b∈B, so there are no objects ab such that a∈A and b∈B; thus, A∘∅=∅
In git: what command can you use to display graphical view of the git branches?
$git log --graph
Complete vs Full Tree
* A full tree has all levels filled. * A complete tree is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible.
What are the types of synchronous exceptions?
* Traps * Faults * Aborts
Describe what goes inside an 802.11 frame header
* Version - protocl v. of 802.11 (2 bits) * Type - type of frame * Subtype 4 bits * Frame Control Flags * Duration Seq # - field used to eliminated duplicate received frames and reassemble fragments * Fragment # - eliminate duplicate received frames
Natural: Signs of a LSE HB? (6)
* highly manipulative * aggressive or passive-aggressive * LOVES drama/gossip * lots of shit tests, but more importantly NO BOUNDARIES on shit tests * victim mentality - "Poor me, poor me" (therapy conversion) * dichotomous signals * SH: overcompensation
Natural: ETC!!!!
-- boyfriend screening -- when was your last boyfriend? why did he break up with me? -- can you cook? (seed the pull) -- super hungry -- im too shy -- go on an adventure (seed the pull) -- only if youre cool -- only if youre nice -- why are you touching me -- sorry wasnt listening was lost in your eyes -- on rejection "call me" , "im too shy" -- lets get married -- hi my sister -- whos that? is that who you cheat on me with? -- no no we cant do this im too shy -- dont tell my girlfriend -- im a virgin -- where r u from. im from hell, heaven -- hes drunk -- grab others, do you approve? -- grab others, this is my sister -- shh
down quark charge
-1/3e
INT_MIN
-2147483648 == -2^31 that means 1 and 31 0's after
**What is event bubbling and what does .live have to do with it?**
.live uses event delegation/bubbling to make it possible to add event handlers to non-existent dom elements event delegation here is by using ancestor for handler for a child element bubbling because the handler exists for all elements because it is attached to a root node i.e. child nodes will bubble up click handlers > The .live() method is able to affect elements that have not yet been added to the DOM through the use of event delegation: a handler bound to an ancestor element is responsible for events that are triggered on its descendants. The handler passed to .live() is never bound to an element; instead, .live() binds a special handler to the root of the DOM tree.
0x2
0010
2
0010
0x6
0110
0x7
0111
7
0111
1001
0x9
1100
0xC
1111
0xF
What numbers have 1s aligned from right to left?
1, 3, 7, 15
How does insertion work in binary heaps?
1. Insert node into leftmost open leaf pos. 2. Compare node with parent, if in correct order, stop 3. If not, swap element and repeat #2-3
2¹⁴
16384
Natural: girls have ... dudes hitting on them
A LOT attempting to be providers
What is a BSS in 802.11
A SS (service set) is a set consisting of all devices associated with a 802.11 IEEEE WLAN. A BSS is a basic service set: one AP with all associated STA's grouped together.
Mood board
A collage, either physical or digital, which is intended to communicate the visual style a direction is heading.
name~10
A commit's nth ancestor is referenced using a tilde (~) followed by the ordinal number. this type of usage is common with rebase -i
@LearnReact (Medium) What are container compoents?
A container does data fetching and then redners its corresponding sub-components. This allows separation of data-fetching and rendering concerns.
STAT244: What is the data frame type in R?
A data frame is used for storing data tables. List of vectors of equal length. Think of it as a sort of db table or excel sheet.
What is a leftmost derivation? (REVIEW THIS, IT's UNCLEAR, what happens when it's unclear what to replace with? That is, the leftmost variable )
A derivation of a string w in a grammar G is a leftmost derivation if at every step the leftmost remaining variable is the one replaced.
What is a die in the context of circuits?
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated. Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon (EGS) or other semiconductor (such as GaAs) through processes such as photolithography Processor die is where the transistors making up the CPU actually reside.
What is a page?
A fixed-length contiguous block of virtual memory.
Workflow diagram
A graphical representation of activities and actions conducted by users of a system. (Sometimes called an activity diagram.)
What is a microprocessor?
A microprocessor is a computer processor which incorporates the functions of a computer's central processing unit (CPU) on a single integrated circuit (IC),[1] or at most a few integrated circuits.[2] A microprocessor is a single-chip implementation of a CPU. Nowadays pretty much all CPUs for general use are microprocessors, causing the two terms to be practically synonymous.
What is an ad-hoc network?
A network that does not rely on a pre-existing infrastructure e.g. routers or AP in wireless networks.
What is a parser?
A parser is a software component that takes input data (frequently text) and builds a data structure - often some kind of parse tree, abstract syntax tree or other hierarchical structure - giving a structural representation of the input, checking for correct syntax in the process. The parsing may be preceded or followed by other steps, or these may be combined into a single step. The parser is often preceded by a separate lexical analyser, which creates tokens from the sequence of input characters; alternatively, these can be combined in scannerless parsing.
What is a "positioned" element?
A positioned element is an element whose computed position property is either relative, absolute, fixed or sticky. -- basically anything but static
What is a process really?
A process is an instance of a running program (PROFOUND IDEA IN CS)
repository
A repository is a collection of commits, each of which is an archive of what the project's working tree looked like at a past date, whether on your machine or someone else's. It also defines HEAD which identifies the branch or commit the current working tree stemmed from. Lastly it contains a set of branches and tags to identify certain commits by name.
What is a seg fault really?
A segfault is really just a page fault that is unable to recover because its unable to get the actual page due to invalid address. SIGSEGV.
What is SOA?
A service-oriented architecture (SOA) is a style of software design where services are provided to the other components by application components, through a communication protocol over a network. The basic principles of service-oriented architecture are independent of vendors, products and technologies.[1] A service is a discrete unit of functionality that can be accessed remotely and acted upon and updated independently, such as retrieving a credit card statement online. A service has four properties according to one of many definitions of SOA:[2] It logically represents a business activity with a specified outcome. It is self-contained. It is a black box for its consumers. It may consist of other underlying services.[3]
What does it mean for set A to be closed under an operation?
A set has closure under an operation if performance of that operation on members of the set always produces a member of the same set; in this case we also say that the set is closed under the operation.
Put shortly, what is a cookie? Name 3 things that a cookie contains.
A small text file stored on your browser: 1. name-value pair containing actual data 2. expiry date after whcih it is no longer valid 3. domain and path of server it should be served to
Describe tokenizer, lexer, parser and how they relate. For example: int x = 5;
A tokenizer breaks a stream of text into tokens, usually by looking for whitespace (tabs, spaces, new lines). A lexer is basically a tokenizer, but it usually attaches extra context to the tokens -- this token is a number, that token is a string literal, this other token is an equality operator. A parser takes the stream of tokens from the lexer and turns it into an abstract syntax tree representing the (usually) program represented by the original text.
What is the vector space?
A vector space (also called a linear space) is a collection of objects called vectors, which may be added together and multiplied ("scaled") by numbers, called scalars in this context. Scalars are often taken to be real numbers, but there are also vector spaces with scalar multiplication by complex numbers, rational numbers, or generally any field. The operations of vector addition and scalar multiplication must satisfy certain axioms.
Description and opposite of abduction - examples
Abduction refers to a motion that pulls a structure or part away from the midline of the body. Opposite of adduction. (Splits : legs are abducted at the hips)
What are aborts?
Aborts are unintentional and unrecoverable synchronous exceptions. Examples: illegal instruction, parity error, machine check
Poached eggs steps
Add a small dash of vinegar to a pan of steadily simmering water. Crack eggs individually into a ramekin or cup. Create a gentle whirlpool in the water to help the egg white wrap around the yolk. Slowly tip the egg into the water, white first. Leave to cook for three minutes. Remove with a slotted spoon, cutting off any wispy edges using the edge of the spoon. Drain onto kitchen paper - nobody wants eggy poaching water making their toast soggy or wilting their salad.
ADD, ADDS
Add two things, set condition flags as necessary for (ADDS)
Description and opposite of adduction - examples
Adduction refers to a motion that pulls a structure or part toward the midline of the body, or towards the midline of a limb. In the case of fingers and toes, it refers to bringing the digits together, towards the centerline of the hand or foot Dropping the arms to the sides, and bringing the knees together, are examples of adduction.
What is an axiom?
An axiom is a proposition regarded as self-evidently true without proof.
Of the three types of data dependencies, which are the easiest to handle?
Anti(WAR) and WAW(Output)
What is a trap/garbage state?
Any state that loops to itself for every given input. Never to return back.
Why is Array Insertion O(n)?
Array insertion is O(n) because you first have to insert the element then need to move all elements after into their right spots. So, if you're inserting at the end it's actually O(1), in the middle O(n/2) and at the beginning O(n) but if you're inserting beyond the array allocated size (typically they're fixed) you would need to reallocate an array which is a slower separate O(n) operation.
Dennard scaling
As transistors get smaller, power density stays constnnt. Dennard scaling failed to address base level power of transistors and leaked power which leads to power wall.
David Deida - Way of the Superior Man (Chapter 1 26:27) - What is masculine Integrity?
Ask. How do I take care of the world? How do I die complete? No matter how much money I make. Setting up your life for integrity, that is managing born responsibilities to serve your deepest purpose.
Define Reactive Programming
Async programming paradigm oriented around data streams and the propagation of changes. This means that static/dynamic data streams are expressed aeasily and that underlying execution model will automaticaly propagate changes through the data flow a := b + c a is being assigned res of b and c. But b and c can be changed later on. In RP when and c are changed a is automatically updated.
What is the difference between asynchronous and synchronous exceptions?
Asynchronous exceptions are called interrupts. (Caused by events EXTERNAL to the processor, indicated by a n interrupt pin) Synchronous exceptiosn occur as a result of executing an instruction.
The left, right child of a node of a binary heap represented as an array is where (1-index and 0-index)?
At 1-index, left child is at 2k, right is at 2k+1 At 0-index, left child is at 2k+1, right is at 2k+2.
If primitives have no properties, why does "abc".length return a value?
Because JavaScript will readily coerce between primitives and objects. In this case the string value is coerced to a string object in order to access the property length.
Regression Analysis: Alpha Value?
Before you run any statistical test, you must first determine your alpha level, which is also called the "significance level." By definition, the alpha level is the probability of rejecting the null hypothesis when the null hypothesis is true. Translation: It's the probability of making a wrong decision. Thanks to famed statistician R. A. Fisher, most folks typically use an alpha level of 0.05.
ANDS
Bitwise AND and set flags Rd = Rn AND imm
What styles are affected to node1? <style> ol li { color: blue; } ol, li { font-weight: bold; } ol > li { font-size: 30px; } ol ~ li { color: yellow; } ol + li { color: green } </style> <html> <ol> <ol> <li>node 1</li> <ul> <li>node 2</li> </ul> <li>node 3</li> <li>node 4</li> </ol> </ol> <li>node 5</li> <li>node 6</li> <li>node 7</li> <ul> <li>node 8</li> </ul> </html>
Bold, blue, font-size: 30
What is a control hazard/dependency?
Branching hazards (also termed control hazards) occur with branches. On many instruction pipeline microarchitectures, the processor will not know the outcome of the branch when it needs to insert a new instruction into the pipeline (normally the fetch stage).
Coroutines vs generators?
But as you may have noticed, generators are all about iterators. Now having a better way to create iterators is obviously great (and this is shown when you define an __iter__() method on an object as a generator), but people knew that if we took the "pausing" part of generators and added in a "send stuff back in" aspect to them, Python would suddenly have the concept of coroutines in Python (but until I say otherwise, consider this all just a concept in Python; concrete coroutines in Python are discussed later on). And that exact feature of sending stuff into a paused generator was added in Python 2.5thanks to PEP 342. Among other things, PEP 342 introduced the send()method on generators. This allowed one to not only pause generators, but to send a value back into a generator where it paused.
ol + li
COMBINATOR: adjacent sibling selector The '+' combinator selects nodes that immediately follow the former specified element. So one node is selected.
In postgres create a table called products with 3 columns product_no, name, price, not null on product_no and name
CREATE TABLE products ( product_no integer NOT NULL, name text NOT NULL, price numeric );
C
Charlie (CHAR-LEE)
What is tree-shaking?
Common JS term used to refer to dead-code elimination or more precisely, live-coe import
Coroutines wiki
Coroutines are computer program components that generalize subroutines for non-preemptive multitasking, by allowing multiple entry points for suspending and resuming execution at certain locations.
What is coupling in computer science?
Coupling is the degree to which each program module relies on each of the other modules.
What is the purpose of double fork()ing?
Creates a daemon process via adoption of process of pid1
CPI, IPC?
Cycles per instruction, Instructions per cycle
**How do you delete branches locally and remotely in Git?**
Delete locally: $git branch -d <branch> Delete remote: $git push origin --delete <branch>
D
Delta (DELL-TAH)
What are the descriptors for finite automata?
Descriptors: * A finite set S of N states (Finite state machine) * A special start state * A set of final (or accepting) states * A set of transitions T from one state to another labeled with chars in C or the alphabet. again: * its states (including start state) * input symbols * initial and final states * transitions on reading input symbols
What are five ways to resolve a flow dependency?
Detect and wait until value is available in register file ! Detect and forward/bypass data to dependent instruction ! Detect and eliminate the dependence at the software level " No need for the hardware to detect dependence ! Predict the needed value(s), execute "speculatively", and verify ! Do something else (fine-grained multithreading) " No need to detect
What is a directive in SASS?
Directives in SASS are reflected with @ symbols in front.
Object.values() var obj = { foo: "bar", baz: 42 }; console.log(Object.values(obj)); var obj = { 0: 'a', 1: 'b', 2: 'c' }; console.log(Object.values(obj)); //
ES2017 (Draft) Object.values() returns an array whose elements are the enumerable property values found on the object. The ordering of the properties is the same as that given by looping over the property values of the object manually. The Object.values() method returns an array of a given object's own enumerable property values, in the same order as that provided by a for...in loop (the difference being that a for-in loop enumerates properties in the prototype chain as well). // ['bar', 42] // ['a', 'b', 'c']
Object.keys() var arr = ['a', 'b', 'c']; console.log(Object.keys(arr)); var obj = { 0: 'a', 1: 'b', 2: 'c' }; console.log(Object.keys(obj));
ES5 Returns: An array of strings that represent all the enumerable properties of the given object. Object.keys() returns an array whose elements are strings corresponding to the enumerable properties found directly upon object. The ordering of the properties is the same as that given by looping over the properties of the object manually. The Object.keys() method returns an array of a given object's own enumerable properties, in the same order as that provided by a for...in loop (the difference being that a for-in loop enumerates properties in the prototype chain as well).
TCP connection teardown states of active closer and passive closer?
ESTABLISHED->FIN_WAIT_1->FIN_WAIT_2->TIME_WAIT->CLOSED ESTABLISHED->CLOSE_WAIT->LAST_ACK->CLOSED
DFA's should be created creatively by using the ability to have a limited amount of memory.
Each state indicates something about the given string. something about the word that has been read so far. So each state has a meaning or an interpretation that can be explained with a comment.
Why can't you see these components on a CPU?
Early CPUs consisted of many separate components, but since the 1970s, they've been integrated into a single unit as a microprocessor. Thus a CPU is a specific TYPE of microprocessor.
How are faults handled?
Either returns to current instruction or aborts.
How do Euclidean vectors relate to vector spaces?
Euclidean vectors are an example of a vector space. They represent physical quantities such as forces: any two forces (of the same type) can be added to yield a third, and the multiplication of a force vector by a real multiplier is another force vector. In the same vein, but in a more geometric sense, vectors representing displacements in the plane or in three-dimensional space also form vector spaces. Vectors in vector spaces do not necessarily have to be arrow-like objects as they appear in the mentioned examples: vectors are regarded as abstract mathematical objects with particular properties, which in some cases can be visualized as arrows.
What does eval do?
Eval evaluates a string and directly executes it in JS
**3NF definition?**
Every non-key attribute must provide a fact about the key, the whole key, and nothing but the key.
React-Router v14: Explain <Route>
Expects a a path prop string to describe pathname to match and uses the package "path-to-regexp"
list.extend(iterable)
Extend the list by appending all the items from the iterable. Equivalent to a[len(a):] = iterable.
**Why is it better to use an in-memory store like redis or memcache for sessions?**
Faster read/write times.
What are faults?
Faults are unintentional but possibly recoverable
Chapter 1 28:30 - David Deida - Feel the ___
Feel the space. Do not postpone your deepest gift just because you do not know. Give it every day. It may change but for now give it no matter what. Do not postpone one more day living your deepest gift.
**When to use for...in vs for each or for**
For is general. For in for object iteration making sure to use .hasOwnProperty due to prototype chain members inherited foreach for side effects on arrays
What are the four forces of nature? Give examples of each
Gravitational, Electromagnetic, Weak Nuclear Forces, Strong Nuclear Forces Gravitational - Weight of object near a planet; force that keeps planets in their orbits around the sun Electromagnetic - Force that keeps an electron in its orbit around the atomic nucleus; (i.e., attraction or repulsion between a "charged" plastic comb and a strand of hair) Strong Nuclear - Force that keeps protons and neutrons together in a nucleus Weak Nuclear - Force responsible for certain types of nuclear reactions - radioactive decay
XD: CMD+G
Group
Generally, what is the algorithm for fitting a grammar into CNF?
Guarantee the start variable doesnt appear on RHS by adding a new start variable and the rule S₀ -> S. Guarantee that epsilons only occur on the RHS of the start, S. This is accomplished by adding rules for every possible outcome of the epsilon rule. Handle all unit rules of A -> B by essentially skipping intermediaries. If B->XY is given, we get A->XY, B->XY. Guarantee there are no rules with more than 2 variables on RHS. E.g. A->BCDE becomes A->BX, X-> CY, Y->DE Guarantee no rules with more than one terminal on RHS. e.g. A->ab becomes A->aU, U->b Guarantee no rules have RHS with 1 variable and 1 terminal. e.g. A->aU becomes G->a and A->GU
**How do POST and GET request body conventions differ?**
HTTP1.1 spec recommends not using bodies for GET and instead use query strings
**How should you store passwords?**
Hash & Salt To Store a Password: Generate a long random salt using a CSPRNG. Prepend the salt to the password and hash it with a standard cryptographic hash function such as SHA256. Save both the salt and the hash in the user's database record. To Validate a Password : Retrieve the user's salt and hash from the database. Prepend the salt to the given password and hash it using the same hash function. Compare the hash of the given password with the hash from the database. If they match, the password is correct. Otherwise, the password is incorrect.
**What is HMAC?**
Hash-based message authentication code. It's a way of implementing a MAC thus results in integrity and authenticity. It can be preferred because its algorithm construction does not reveal plaintext.
According to Linus Torvalds, explain what a good git commit message is
Header line: explain commit message ine one line. Body of commit message can be several paragraphs, cols < 74 Explain why Resolves: Insert issue numbers here See also: Relevantt issues.
The Natural: Comfort test subtext
Hey I really like you, please prove that you're not one of those.
Degrees of Freedom Explanation:
I like this earlier answer on the same topic: If I have a vector of length ten that can take any values, then you need all ten coordinates to know what the vector is, and there are ten degrees of freedom. If I tell you that the sum of the elements of the vector is zero, then any nine of the coordinates determine the tenth, and there are nine degrees of freedom. If I also tell you that the sum of the squares of the elements of the vector is one, then any eight of the coordinates determine the last two, and there are eight degrees of freedom. If I tell you that the vector is parallel to a fixed vector, then there's only one degree of freedom, which corresponds to the ratio of the coordinates of the two vectors. The key idea is that the degrees of freedom is the minimum number of values that you need to specify a quantity. If you're comfortable with geometry in the abstract, you can think of the degrees of freedom as the dimension of the space that the numbers "live in".
In Javascript, Numbers follow what encoding?
IEEE754 Standard
What are the 5 stages of a classic RISC pipeline?
IF, ID, Execute, Mem Access, Writeback
RIP, IS-IS, OSPF are protocols of ...
IGP (interior gateway protocols) which means within an AS.
Explain Network Address Translation (IP masquerading) on a Router
IP masquerading is a technique that hides an entire IP address space, usually consisting of private IP addresses, behind a single IP address in another, usually public address space. The address that has to be hidden is changed into a single (public) IP address as "new" source address of the outgoing IP packet so it appears as originating not from the hidden host but from the routing device itself. Because of the popularity of this technique to conserve IPv4 address space, the term NAT has become virtually synonymous with IP masquerading.
**What is the referer header?**
Identifies the address that linked to the resource being requested
What are prepared statements?
In DBMS, feature used to execute similar db statements faster. Reduces overhead of compiling and opimtizing the statement.
Why are uppercase and lowercase ASCII chars separated by so much in decimal representation?
In binary, uppercase letters will start off with 100 where there are 7 bits. Whereas lowercase letters will start off with 110. This means you can convert from uppercase to lowercase by toggling one bit! That is the 2^6 bit!
**How does text-align affect inner elements?**
It is applied to block elements and inherited. But affects inline and text elements nested within.
Express Kleene star in terms of Kleene plus
L* = {e} U L+
**What is the accept-language header?**
List of acceptable human languages for response.
What is body copy?
Main text part of an advertisement or any printed matter (as distinct from the logo, headline, subheadings, and graphics) that provides the 'meat' of the communication. Usually a professional copywriter writes the body copy. Read more: http://www.businessdictionary.com/definition/body-copy.html#ixzz4DSxSFCe5
Describe the layout category.
Major containing elements Layouts contain one or more modules Grid system Grouping of contents ID selectors Intuition: e.g. Header, content, sidebar, e.g. Header, main nav, secondary content, featured content, tertiary content
**What is logarithmic growth?**
Many things in nature are logarithmic, i.e. skill acquisition - logarithms are inverse of exponents, visualize the graph
**If you have a block element how do you horizontally center it?**
Margin: 0 auto onto the element that needs to be centered
**what is authenticity in security?**
Message is coming from stated sender
What is middleware?
Middleware is a general term for software that serves to "glue together" separate often complex and already existing programs. Unix Pipe-like
Non-square matrices don't have what?
Non-square matrices are non-invertible.
**Neural nets are learning algorithms good for modelling...?**
Nonlinear hypotheses.
**Can you add event handlers to dynamically added content?**
Not unless specifically coded to do so. This is because JQ loads after doc.ready so dom elements wont be present at load time aka nothing to addEventListener to. JQuery works around this by using event delegation
What is the guaranteed height on a balanced search tree?
O(log(n)) for n items. Specifically, 2log_2(n+1)
**What is the time complexity of array resizing?**
O(n) - need to move old array content into new array after creating double sized
Define O(n),θ(n) and Ω(n) in T(n) (function being analyzed) and F(n) (function being expressed)
O(n) - usually the worst case running time. If eventually, for al sufficiently large n, T(n) is bounded above by a constant multiple of f(n) T(n) = O(f(n)) iff there exists constants c, n₀ s.t. T(n) ≤ c * f(n) T(n) = Ω(f(n)) iff there exists c, n₀ constants s.t. T(n) ≥ c * f(n) for all n ≥ n₀ T(n) = θ(f(n)) iff T(n) = O(f(n)) and T(n) = Ω(f(n)) use bar location to remember. Theta is when its bounded by c * f(n) for same function, but c could differ.
Integral means...
Of, pertaining to, or being an integer. So it's not some mystical calculus term.
What does context switching have to do with concurrency?
Parallel is the opposite of serial. Concurrent is the opposite of sequential. Vector is the opposite of scalar. Thus, concurrency is often shown via context switching between processes.
What are the three mutually exclusive states of promises?
Pending. Fulfilled. Rejected.
Explain React.Copmonent(setState)
Performs a shallow merge of nextState into current state. This is the primary method you use to trigger UI updates from event handlers and server request callbacks. The first argument can be an object (containing zero or more keys to update) or a function (of state and props) that returns an object containing keys to update.
React Virtual DOM allows what..
React Native and cross-platform targeting pretty much.
REST says what about protocols? and client v server?
Should be stateless. There should be a separation of concern between Client ansd Server?
What are the three parts of IEEE754?
Sign, Exponent, Mantissa
What is Elm-Reactor?
Some IDE for easier ELM dev has support for time-travelling.
Producer-consumer pattern
Someone is generating data and at the other end someone is receiving data, using a common, fixed-size buffer.
Rank the forces in nature by both range and relative strength
Strong (strongest), Electromagnetic, Weak, Gravitational Grav (inf) Electromagnetic (inf) Strong 10^-15, Weak 10^-18
STAT244: What is the factor collection type?
Take on a limited number of different values that re usually categorical variables. Stored as a vector of integer values with orresponding set of characteristics
T
Tango (TANG-GO)
What is fe80::/10?
The link-local addresses (think about the terminology used here). Takes routing address as first 64 bits and MAC as next 64 (in a sense since MACs are 48), guaranteeing at least one address will work in the network.
General good guideline for typography measure?
The measure is the amount of characters on a line. Around 50-80 characters is best for readability. If the measure is too long, the reader will have a harder time finding the start of the next line while reading.
What is the "arity" of a function?
The number of arguments or operands that the function takes.
What is a mantissa?
The part of a common logarithm after the decimal point, the fractional part of a logarithm. OR The significand; that part of a floating-point number or number in scientific notation that contains its significant digits.
What is a user agent?
The piece of software that understands HTTP requests, typically used in the context of HTTP. In computing, a user agent is software (a software agent) that is acting on behalf of a user.
**What does y represent in logistic regression?**
The set of categorical variable outputs possible.
**when defining - why do we divide by 1/2?**
This is simply to make calculation easier when we hypothetically apply gradient descent
Frequent pairing of fonts for material?
Two sans-serifs, or one sans-serif for headlines and serif for body copy.
How many outputs does a half-adder have?
Two! One for C_out and one for Sum
**What is THETA in Machine Learning?**
Typically theta represents a vector of feature WEIGHTS -- not all features have the same impact on prediction
What is a query string?
Typically used with GET requests -- You encode the information that a client is sending to server using a querystring which usualyl has the form ?parameter=value¶metervalue&.... POST methods on the other hand are intended to affect resources and its parameters and values are tyically encoded in the request payload not in the URI.
What timezone are cookie expiry dates set in?
UTC (Greenwich)
UTF-16?
UTF-16: 2 bytes per "code unit" in Unicode!
How do you convert a binary heap into an array while still maintaining properties?
Use level order traversal into an array.
How do you implement DFS?
Use recursion with memory being the stack, or use another stack.
How to run custom scripts and debug in console?
Use snippets from Chrome devtools
**What is the accept header?**
Used to indicate what MIME types to accept.
What is a write policy in reference to caches?
When a system writes data to cache, it must at some point write that data to the backing store as well. The timing of this write is controlled by what is known as the write policy.
Merge A-B-C-D \ -W - X - Y - Z results? What's at Z^?
Z^ is the old Z before merge and Z contains (Z+D) due to merge commit.
what are the 8 attribute selectors?
[attr] Represents an element with an attribute name of attr. [attr=value] Represents an element with an attribute name of attr and whose value is exactly "value". [attr~=value] Represents an element with an attribute name of attr whose value is a whitespace-separated list of words, one of which is exactly "value". [attr|=value] Represents an element with an attribute name of attr. Its value can be exactly "value" or can begin with "value" immediately followed by "-" (U+002D). It can be used for language subcode matches. [attr^=value] Represents an element with an attribute name of attr and whose first value is prefixed by "value". [attr$=value] Represents an element with an attribute name of attr and whose last value is suffixed by "value". [attr*=value] Represents an element with an attribute name of attr and whose value contains at least one occurrence of string "value" as substring. [attr operator value i] Adding an i (or I) before the closing bracket causes the value to be compared case-insensitively (for characters within the ASCII range).
Electromagnetism is what?
a type of physical interaction that occurs between electrically charged particles.
STAT244: in R, plot takes what args?
a vector for X and a vector for Y
Given the tuple ({S},{a,b}, R, S} where the set of rules are S -> aSb | SS | ε, what types of strings are generated? What do you notice about this language?
abab, aaabbb, aababb. The language enforces a and b to act almost like parentheses.
**Format of accept header?**
accept, media-range:type/subtype, qvalues "Accept : text/plain; q=0.5, text/html, text/x-dvi; q = 0.8, text/x-c"
**How do you center an element vertically and horizontally using flexbox?**
add display: flex; to parent, justify-content: center; align-items: center;
What are TRIVIAL proofs?
any theorem, no matter how difficult to prove in the first place, is viewed as "trivial" by mathematicians once it has been proven. Therefore, there are exactly two types of mathematical objects: trivial ones, and those which have not yet been proven. - richard feynman
**What is the syntax for expression invaluated in es6 template literals?**
backticks, ${}; `string text ${expression} string text`
**Three ways to handle errors?**
callback - in node use error first syntax (for async) with `Error` event throw, try/catch (for sync that indicates this should never happen as it halts execution)
Serialize and deserialize a BST
class Codec: def serialize(self, root): def preorder(node): if node: vals.append(str(node.val)) preorder(node.left) preorder(node.right) vals = [] preorder(root) return ' '.join(vals) def deserialize(self, data): return data; def buildTree(self, preorder, inorder): def build(stop): if inorder and inorder[-1] != stop: root = TreeNode(preorder.pop()) root.left = build(root.val) inorder.pop() root.right = build(stop) return root preorder.reverse() inorder.reverse() return build(None)
**How to delete until matching brace in vim?**
d%
Chapter 1 31:13 - David Deida - For one to discover his deepest masculine purpose. The feminine is change. Requires that you develop the capacity to simply .... your .... and body as they .... without ...
develop the capacity to simply love your mind and body as they change without believing in what they tell you too much.
Given set A = {1,2,3} and B = {4,5,6} you can describe these sets as...
disjoint
Of the following, order from bottom of tech stack to higher levels. signals exceptions nonlocal jumps process context switch
exceptions process context switch signals nonlocal jumps
How do you represent negative zero in IEEE754?
exponent and mantissa == 0 0 00000000 00000000000000000000000 = 0 1 00000000 00000000000000000000000 = -0
Sum of an arithmetic sequence of numberS?
first + last * n / 2
Code up a solution to the max sum subarray problem.
function maxSumSubarray(nums){ let maxOverall = 0; let maxEndingHere = 0; for (let i = 0; i < nums.length; i++){ maxEndingHere = Math.max(maxEndingHere + nums[i], nums[i]); maxOverall = Math.max(maxEndingHere, maxOverall); } return maxOverall; } function maxSumSubarray(nums){ let maxOverall = nums[0]; let maxEndingHere = nums[0]; for (let i = 1; i < nums.length; i++){ maxEndingHere = Math.max(maxEndingHere + nums[i], nums[i]); maxOverall = Math.max(maxEndingHere, maxOverall); } return maxOverall; }
Explain the rod-cutting problem
givena rod of length n inches, and a table of prices p_i for i = 1,2,...n determine maximum revenue obtainable by cutting up the rod and selling the pieces.
What does it mean when correlation is equal to 0?
http://stattrek.com/statistics/correlation.aspx?Tutorial=AP The sign and the absolute value of a correlation coefficient describe the direction and the magnitude of the relationship between two variables. The weakest linear relationship is indicated by a correlation coefficient equal to 0. A positive correlation means that if one variable gets bigger, the other variable tends to get bigger. A negative correlation means that if one variable gets bigger, the other variable tends to get smaller. Keep in mind that the Pearson product-moment correlation coefficient only measures linear relationships.
Compare and contrast generators and iterators?
https://stackoverflow.com/questions/1022564/what-is-the-difference-between-an-iterator-and-a-generator Generators are iterators, but not all iterators are generators. An iterator is typically something that has a next method to get the next element from a stream. A generator is an iterator that is tied to a function.
What are traps?
intentional exceptions caused by instructions (breakpoints, system calls, etc)
The Natural: Arousal buildup?
kino basically.. bite neck ear breathing grab waist pull in
Why is the codomain and domain necessary in a function definition?
let f be the function from x maps to x^2 -- why is this an incorrect function defintion? you must define the codomain and domain first. let f be the function from real numbers to real numbers mapping x to x^2 why? because the defintiion of a function requires that for every input there is one output and the codomain plays a vital role in making this property satisfied. take for example square root of x mapping. this is invalid for all positive and negative numbers, but valid for just positive numbers also DRASTICALLY impacts what class of function a given function is i.e. surjective, bijective, injective
**Primitive vs Non-primitve types in JS are handled differently, how so?**
level 1. Non-primitives are passed by reference and primitives are by refernce level 2. Non-primitives and primitives are handled the same, it's all pass by value, but for objects val of variable is a reference In other words, the confusing thing here isn't pass-by-value/pass-by-reference. Everything is pass-by-value, full stop. The confusing thing is that you cannot pass an object, nor can you store an object in a variable. Every time you think you're doing that, you're actually passing or storing a reference to that object. But when you go to access its members, there's a silent dereferencing that happens, that perpetuates the fiction that your variable held the actual object. So ultimately, it's call-by-sharing. (Liskov) A param reference is not changed (i.e. doesn't persist outside of the function call itself) unless you go ahead and change the members within that parameter.
$pgrep -u does what? $pgrep -v
list processes for a user, list processes not owned by a particular user. inverse works for grep too!!!
**What does a caret in brackets(character class) indicate?**
match what is NOT whats inside
**why attach new functions to .prototype? what are the two benefits? one downside?**
methods that inherit via the prototype chain can be changed universally for all instances better performance than on the function itself, because everytime the constructor runs, the method has to be created one downside is that functions via prototypal chain inheritance do not have access to private variables
AND
p 408 Bitwise AND Rd = Rn AND imm
What is momentum in physics?
p = m*v
parameters vs arguemnts
parameters are variables in the declaration of the function argument is the actual value of this variable that gets passed to the function
**What does regularization help us do?**
regularization helps us prevent overfitting which is possible when our hypothesis function may have too many features
position: fixed
relative to the window Do not leave space for the element. Instead, position it at a specified position relative to the screen's viewport and don't move it when scrolled. When printing, position it at that fixed position on every page. This value always create a new stacking context. Fixed positioning fixes the position of an element relative to the browser window.
PATCH request?
requests a set of changes described.
What is the default value for CSS property position - what does it mean?
static
**How to convert string to ASCII?**
str.charCodeAt(0);
**How to remove whitespace in JS strings?**
str.replace(/\s+/, ''); -- the + is for performance optimization
How does String.prototype.replace() work?
str.replace(regexp|substr, newSubStr|function) Return val: A new string with some or all matches of a pattern replaced by a replacement. Pretty crazy. Callback takes in following params: **match** -- The matched substring. (Corresponds to $& above.) **p1, p2, ..**. -- The nth parenthesized submatch string, provided the first argument to replace() was a RegExp object. (Corresponds to $1, $2, etc. above.) For example, if /(\a+)(\b+)/, was given, p1 is the match for \a+, and p2 for \b+. offset (Note that this means that the # of callback args varies and this only works for capturing groups AFAIK) **offset** -- the offset of the matched substring within the whole string being examined. (For example, if the whole string was 'abcd', and the matched substring was 'bc', then this argument will be 1.) **string** -- The whole string being examined.
What CSS property determines underlining text?
text-decoration
**What is the mathematical constant, e, what are its three properties?**
the mathematical constant e represents growth. it is flexible, it is growth, it is continuous e^x is exponential growth compounded continuously
**what is the constructor pattern?**
this is the basic pattern of JS where the "new" keyword is used with function constructors you can also add functions to the prototype which Osmani calls "constructors with prototypes"
position: static
this is the initial value for the position property. it doesnt allow you to use top,left,right,bottom, or z-index - no effect.
How do you notate the speech "u derives v"?
this is... if u=v or if a sequence u₁,u₂,...u_k => v exists for k ≥0 and u => u_1 => u_2 .... u_k => v
What operations is the class of regular languages closed under?
union, concatenation, intersection, complement, (optional info) difference, reversal, homomorphism, inverse homomorphism
**For loops that use (let i = 0; i < num; i++) print i evaluate until**
until one less than num. this is why array.length works in places like this for zero-indexed arrays
How to find if one string contains another substring?
use String.prototype.indexOf()
#How to remove an index from an array with no empty slots?
use `array.splice(index, 1)`
$w does what?
w -- display who is logged in and what they are doing
Explain the importing problem and its solution
with regular css the tendency is to use multiple stylesheets with a respective http request for each oen how can we fix this? @import into one stylesheet at the end
What is a synonym to string in automata theory?
word
JS: Three properties of objects?
writable, configurable, enumerable
Write allocate
write allocate means on a write miss, to allocate the block from memory to cache, then write to the cache.
Describe the top-down w/memoization d.p. method
write procedure recurisively in a natural manner, but save result of each subproblem (in usually an array or htbl) procedure now checks to see if it hsas already solved the subproblem, if so, return that value, and save computation else compute value as usual.
What styles are affected to node6? <style> ol li { color: blue; } ol, li { font-weight: bold; } ol > li { font-size: 30px; } ol ~ li { color: yellow; } ol + li { color: green } </style> <html> <ol> <ol> <li>node 1</li> <ul> <li>node 2</li> </ul> <li>node 3</li> <li>node 4</li> </ol> </ol> <li>node 5</li> <li>node 6</li> <li>node 7</li> <ul> <li>node 8</li> </ul> </html>
yellow, bold
How do you attach to a docker process?
$docker ps --> see what containers are running $docker attach <sha or name>
What does -xe do for Bash?
-e -> exit immediately -x -> print commands and arguments as they are executed.
What are the 5 properties in defining a B-Tree of order m?
1. A node has at most "m" children 2. A node with k children has k-1 keys 3. Any inner node has at least ceiling (m/2 children) 4. All leaves must be at same depth. 5. Root must have at least 2 children
Order the SQL statements for execution: SELECT DISTINCT column, AGG_FUNC(column_or_expression), ... FROM mytable JOIN another_table ON mytable.column = another_table.column WHERE constraint_expression GROUP BY column HAVING constraint_expression ORDER BY column ASC/DESC LIMIT count OFFSET COUNT;
1. FROM and JOIN 2. WHERE 3. GROUP BY 4. HAVING 5. SELECT 6. DISTINCT 7. ORDER BY 8. LIMIT / OFFSET https://sqlbolt.com/lesson/select_queries_order_of_execution
You can sometimes still perform a FTS on a DB table with an index on it. How so? (2 cases)
1. Where clause in columns has no matches of leading columns of index. 2. If where cluase doesnt prevents use of index i.e. NEQ, NOT, starting with wildcard %hello%
Full Text Search has 3 steps in preprocessing in Postgres -- what are they?
1. parse document into tokesn 2. convert tokens into lexemes (normalization, stemming) 3. store preprocessed documents optimized for searching.
Redux: Actions are...
1. payloads of ___ that send ___ to __ 2. __ source of info for state 3. plain js objects 4. must have "type" property
Redux: reducers are what type of function, what args, what does it return? what are 3 things not to do with reducers
1. pure function 2. args: previous state, action 3. returns new state 4a-c - DONT mutate args, preform side-effects call non-pure functions
Why can creating an index interfere with regular operation of a database?
A table is locked when indexed against.
Describe the TSVECTOR type in Postgres
A tsvector is a sorted list of distinct lexemes that are words that have been normalized to make different variants of the same word look alike. For example, normalization almost always includes folding upper-case letters to lower-case and often involves removing suffixes. This allows searches to find variant forms of the same word w/o tediously entering all the possible variants.
What's a view in a databasE?
A view is just a way to get results set of a query. It is really just a view. It may be slightly faster but for efficiency, it's rpreferred to just use materialized views.
What does ACID stand for and define each one?
Atomicity - Atomicity requires that each transaction be "all or nothing": if one part of the transaction fails, then the entire transaction fails, and the database state is left unchanged. An atomic system must guarantee atomicity in each and every situation, including power failures, errors and crashes. To the outside world, a committed transaction appears (by its effects on the database) to be indivisible ("atomic"), and an aborted transaction does not happen Consistency - The consistency property ensures that any transaction will bring the database from one valid state to another. Any data written to the database must be valid according to all defined rules, including constraints, cascades, triggers, and any combination thereof. This does not guarantee correctness of the transaction in all ways the application programmer might have wanted (that is the responsibility of application-level code), but merely that any programming errors cannot result in the violation of any defined rules. Isolated - The isolation property ensures that the concurrent execution of transactions results in a system state that would be obtained if transactions were executed sequentially, i.e., one after the other. Providing isolation is the main goal of concurrency control. Depending on the concurrency control method (i.e., if it uses strict - as opposed to relaxed - serializability), the effects of an incomplete transaction might not even be visible to another transaction. Durable - The durability property ensures that once a transaction has been committed, it will remain so, even in the event of power loss, crashes, or errors. In a relational database, for instance, once a group of SQL statements execute, the results need to be stored permanently (even if the database crashes immediately thereafter). To defend against power loss, transactions (or their effects) must be recorded in a non-volatile memory.
the index
Changes are first registered into the index "staging area".
What is cooperative multitasking?
Cooperative multitasking, also known as non-preemptive multitasking, is a style of computer multitasking in which the operating system never initiates a context switch from a running process to another process. Instead, processes voluntarily yield control periodically or when idle in order to enable multiple applications to be run simultaneously. This type of multitasking is called "cooperative" because all programs must cooperate for the entire scheduling scheme to work. In this scheme, the process scheduler of an operating system is known as a cooperative scheduler, having its role reduced down to starting the processes and letting them return control back to it voluntarily.[1][2]
HEAD
HEAD is used by repo to define what is currently checked out. If you checkout a branch, head symbolically refers to that branch, indicating that the branch name should be updated after the next commit operation. If you checkout a specific commit, HEAD refers to that commit only. This is referred to as a detached HEAD and occcurs for example if you check out a tag name.
What is __path__?
If the module is a package (either regular or namespace), the module object's __path__ attribute must be set. The value must be iterable, but may be empty if __path__ has no further significance. If __path__ is not empty, it must produce strings when iterated over. More details on the semantics of __path__ are given below. Non-package modules should not have a __path__ attribute.
What is a database cursor?
In computer science, a database cursor is a control structure that enables traversal over the records in a database. Cursors facilitate subsequent processing in conjunction with the traversal, such as retrieval, addition and removal of database records. The database cursor characteristic of traversal makes cursors akin to the programming language concept of iterator. Cursors are used by database programmers to process individual rows returned by database system queries. Cursors enable manipulation of whole result sets at once. In this scenario, a cursor enables the rows in a result set to be processed sequentially. In SQL procedures, a cursor makes it possible to define a result set (a set of data rows) and perform complex logic on a row by row basis. By using the same mechanics, a SQL procedure can also define a result set and return it directly to the caller of the SQL procedure or to a client application. A cursor can be viewed as a pointer to one row in a set of rows. The cursor can only reference one row at a time, but can move to other rows of the result set as needed.
What is an aggregate function?
In database management an aggregate function is a function where the values of multiple rows are grouped together as input on certain criteria to form a single value of more significant meaning or measurement such as a set, a bag or a list.
list.insert(i, x)
Insert an item at a given position. The first argument is the index of the element before which to insert, so a.insert(0, x) inserts at the front of the list, and a.insert(len(a), x) is equivalent to a.append(x).
What does it mean to fast-forward in git?
It means to just move the pointer for the branch up a bunch of commits and to have an updated branch.
How many processes can run on a single CPU?
Only one process can run at a time on a single CPU. All other processes have to wait or be in some other state. This is why a process that is not running appears in a different state. States include the following: • Runnable state • Sleeping state • Uninterruptable sleep state • Defunct or Zombie state https://access.redhat.com/sites/default/files/attachments/processstates_20120831.pdf
Redux: dispatch(action)
Only way to trigger a state change
Description and opposite of extension - examples
Opposite of extension is flexion: Extension is increasing the angle between two body parts. When standing up, the knees are extended.
Description and opposite of flexion - examples
Opposite of flexion is extension: Flexion is decreasing the angle between two body parts. When sitting down the knees are flexed.
React-Router v14: React-Router is broken into three things what are they?
React-router, react-router-dom, react-router-native
Precision vs Recall Tradeoff - what is the precision and recall of the diagram?
Recall - 1/3 - 33% Precision - 1/4 - 25% In the example only 1 relevant result of 3 possible relevant results was returned, so the recall is a very low ratio of 1/3, or 33%. The precision for the example is a very low 1/4, or 25%, since only 1 of the 4 results returned was relevant. Basically precision - is what was returned relevant? recall - how many relevant things were returned? Full-text-search systems typically includes options like stop words to increase precision and stemming to increase recall.
list.clear()
Remove all items from the list. Equivalent to del a[:].
list.remove(x)
Remove the first item from the list whose value is x. It is an error if there is no such item.
list.pop([i])
Remove the item at the given position in the list, and return it. If no index is specified, a.pop() removes and returns the last item in the list. (The square brackets around the i in the method signature denote that the parameter is optional, not that you should type square brackets at that position. You will see this notation frequently in the Python Library Reference.)
list.copy()
Return a shallow copy of the list. Equivalent to a[:].
External Rotation
Rotation of body parts is referred to as internal or external, referring to rotation towards or away from the center of the body.[20] Internal rotation (or medial rotation) refers to rotation towards the axis of the body.[20] External rotation (or lateral rotation) refers to rotation away from the center of the body.[20
Internal Rotation
Rotation of body parts is referred to as internal or external, referring to rotation towards or away from the center of the body.[20] Internal rotation (or medial rotation) refers to rotation towards the axis of the body.[20] External rotation (or lateral rotation) refers to rotation away from the center of the body.[20
What is a stored procedure?
Stored procedures are a sequence of instructions in PL/SQL language. Is a programming language implemented by some DBMS, that lets you store sequences of queries frequently applied to your model, and share the processing load with the application layer. Prepared statements are queries written with placeholders instead of actual values. You write the query and it is compiled just once by the DBMS, and then you just pass values to place into the placeholders. The advantage of using prepared statements is that you enhance the performance considerably, and protect your applications from SQL Injection. The difference is you cant store prepared statements. You must "prepare" them every time you need to execute one. Stored procedures, on the other hand, can be stored, associated to a schema, but you need to know PL/SQL to write them. You must check if your DBMS supports them. Both are very usefull tools, you might want to combine. Hope this short explanation to be useful to you!
Tag
Tag is also a name for a commit similar to branch except that it always names the same commit.
What is __name__?
The __name__ attribute must be set to the fully-qualified name of the module. This name is used to uniquely identify the module in the import system. Global
Multitenancy
The term "software multitenancy" refers to a software architecture in which a single instance of software runs on a server and serves multiple tenants. A tenant is a group of users who share a common access with specific privileges to the software instance. With a multitenant architecture, a software application is designed to provide every tenant a dedicated share of the instance - including its data, configuration, user management, tenant individual functionality and non-functional properties. Multitenancy contrasts with multi-instance architectures, where separate software instances operate on behalf of different tenants. [1]
What is an IDL? What is Apache Thrift?
This is where Apache Thrift comes in. It has its own "Interface Definition Language" (IDL). In this language you define what are the functions and what are their parameters. And then use Thrift compiler to generate corresponding code for any language of your choice. What this means, is that you can implement a function in java, host it on a server and then remotely call it from python.
Leg : Two major bones that are in between front calf muscles
Tibia, fibula
How are coroutines like mutual recursion?
Using coroutines for state machines or concurrency is similar to using mutual recursion with tail calls, as in both cases the control changes to a different one of a set of routines. However, coroutines are more flexible and generally more efficient. Since coroutines yield rather than return, and then resume execution rather than restarting from the beginning, they are able to hold state, both variables (as in a closure) and execution point, and yields are not limited to being in tail position; mutually recursive subroutines must either use shared variables or pass state as parameters. Further, each mutually recursive call of a subroutine requires a new stack frame (unless tail call elimination is implemented), while passing control between coroutines uses the existing contexts and can be implemented simply by a jump.
What datastructure is used fo rindices on DBs?
Usually a b-tree, sometimes hashtables, or other specifc data structures.
list = [1,2,3] list.index(3,0,0) returns...?
ValueError: 3 is not in list
Postgres commands for - listing all databases, connecting/switching to a database, getting help, listing all tables
\list \dt \connect \?
Branch
a branch is just a name for a commit also called a refernce. It's the parentage of a commit which defines its history.
Commit
a commit is a snapshot of your working tree at some point in time. The state of HEAD at the time of your commit is made becomes that commit's parent. This is what creates the notion of a "revision history"
sort() vs sorted()
sort() in-place List.sort() returns None sorted() - returns new sorted list
Coroutines are a type of...
subroutine.
name^ in git
the parent of any commit is referenced using the caret symbol. if a commit has more than one parent, the first is used.
**What session implementation allows you to avoid using a database or memory for cookies?**
Client-side cookies
How many Mac Addresses does a 802.11 frame have?
Four
What is Instruction Level Parallelism?
Measure of instructions that can be ran in parallel - "Increase ILP with OOO or pipelining"
Memoization vs DP?
Memoization is a term describing an optimization technique where you cache previously computed results, and return the cached result when the same computation is needed again. Dynamic programming is a technique for solving problems recursively and is applicable when the computations of the subproblems overlap. Dynamic programming is typically implemented using tabulation, but can also be implemented using memoization. So as you can see, neither one is a "subset" of the other. A reasonable follow-up question is: What is the difference between tabulation (the typical dynamic programming technique) and memoization? When you solve a dynamic programming problem using tabulation you solve the problem "bottom up", i.e., by solving all related sub-problems first, typically by filling up an n-dimensional table. Based on the results in the table, the solution to the "top" / original problem is then computed. If you use memoization to solve the problem you do it by maintaining a map of already solved sub problems. You do it "top down" in the sense that you solve the "top" problem first (which typically recurses down to solve the sub-problems).
M
Mike (MIKE)
Bauhaus characteristics?
Staatliches Bauhaus (About this sound listen (help·info)), commonly known simply as Bauhaus, was an art school in Germany that combined crafts and the fine arts, and was famous for the approach to design that it publicised and taught. It operated from 1919 to 1933. At that time, the German term About this sound "bauhaus" (help·info)—literally "construction house"—was understood as meaning "School of Building". One of the main objectives of the Bauhaus was to unify art, craft, and technology, and this approach was incorporated into the curriculum of the Bauhaus. Bauhaus was in the modernist period. Bauhaus characteristics: Rule #1: Form follows function "Form follows function" is a sentence coined by Louis Sullivan, an American architect, who wanted to express the futility in excessive ornamentations, and was central to thinking in the Bauhaus school. Rule #2: Typography Matters -preferred sans-serif -frequently didnt mix uppercase with lowercase Rule #3Geometry is King - inspiration from cubist artists Clean, abstract and geometric forms were constantly used to produce new common tools that could highlight the difference from the old trends of the Art Nouveau.
What part of IPv6 is the host?
The second set of 64 bits is the host. This is nice because MAC addresses are unique and 48 bits, so can fit in nicely with extra space.
#find sum of arithmetic sequence with diff of 1?
n*n+1 / 2
XD: CMD+SHIFT+G
ungroup
What are the elementary row operations?
1. Interchange two rows or columns (swap) 2. Multiply each element in a row or column by a non-zero value. 3. Multiply a row or column by a nonzero # and add result to another row or column.
What are the 3 steps of an exchange argument proof?
1. Label your current algorithm as A. Label an optimal algorithm as O(in this example). 2. Assume that the optimal solution is not the same as your greedy algorithm. 3. Exchange or swap elememnts in O to move it like A.
What are the three newtonian laws
1. Law of inertia. 2. F=ma 3. Action-reaction
Rules of shortening IPv6?
1. Leading zeros in a group may be omitted, but each group must be taking at least 1 hex digit except if its the first digit 2. one or more consecutive groups of zero values may be replaced with a single empty group using 2 consecutive colons (::)
Describe red-black trees in 4 points (michael sambol)
1. Node is either red or black 2. The root and the leaves are black ?? 3. If a node is red, then its children are black 4. All paths from a node to its nil descendants contain the same number of black nodes.
What are the four ways to typecast to a Number?
1. Number(x); 2. parseInt(x, 10); 3. parseFloat(x); 4. +x;
0xF
15
react elements vs components?
1. react elements describes what you see on the screen 2. react element is an object representation of a dom node a component is afunction or a class which optionally accepts input and returns a react element
Redux: What are the 3 principles of redux?
1. single source of truth The state of your whole application is stored in an object tree within a single store. 2. state is read-only "Action" The only way to change the state is to emit an action, an object describing what happened. 3. Changes are made with pure functions To specify how the state tree is transformed by actions, you write pure reducers.
Define these variables in AWK: $0, $1 $(NF-2) $NR
$0 - full line $1 - first field $(NF-2) - number of fields - 2 Awk NR gives you the total number of records being processed or line number.
**How do you unstage a file in a commit in Git?**
$git rm --cached <filePath> - stages removal $git reset <filePath> - unstages Here is one way to think about it: git rm --cached [file] This simply removes a file from being tracked (the state a file is in after it is added - i.e. git add [file]) -- no longer keeps track... git reset HEAD [file] This simply continues to keep tracking changes to the file, but will place it back into the 'unstaged' area. --keeps tracking but not staged. http://stackoverflow.com/questions/17122480/difference-between-git-rm-cached-and-git-reset-head
What command is used to get system information in Linux?
$uname
Say there's a user on a system named anthony running vim. How to kill all procs launched from his terminal? then kill his ssh terminal?
$w (find out what tty he's hooked to) $pkill -t pts/1 $pkill -u anthony sshd
0xA
10
Hard boiled egg time in boiling water?
10-12 minutes
9
1001
0xA
1010
11
1011
2¹⁰
1024
AI: Shift Arrow Nudging
10x the nudge amount
How many characters in standard ASCII?
128
How do you describe a CFG?
4-Tuple, Variables, Terminals, Rules, Start Variable Note that the variables and the terminals are DISJOINT. Often these are renamed as nonterminal symbols and terminal symbols.
2¹²
4096, 16³
How Long is a MAC address?
48 bits or 6 octets.
2⁹
512
What is a in ASCII?
97 - 110001
**Lowercase letters in ASCII start and end?**
97-122
What is the unspecified address in IPv6?
::
What is the loopback address in IPv6?
::1 or 0:0:0:0:0:0:0:1
Status Line looks like, Request Line looks like ? (HTTP)
<PROTOCOL> <CODE> <MSG> <ACTION> <URI> <PROTOCOL>
What is the semantic way for <div id="wrapper></div>
<main></main>
React-Router v14: How do you group Rotes and render only the first that matches the path passed in?
<switch>
Peering vs settlement freeness
???? TODO
**How to get full URL of current website?**
window.location.href
Definition of language of a grammar?
{ w ∈ ∑* | S derives w} (notated with S =>* w) where S is the start variable. This says "if there is at least one derivation that yields w"
Regular Expressions: Σ∗001Σ∗ evaluate
{w| w contains the string 001 as a substring}.
The length of a string is denoted...
|w| where w is the string or word
**What does the spread operator do that's similar to Function.prototype.apply?**
Allows you to pass an array as arguments to a function
What is an integrated circuit?
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small plate ("chip") of semiconductor material, normally silicon
Pete Hunt "Rethinking Best Practices" : React Components are basically just idempotent functions, what does idempotent mean in this context?
An operation that will produce the same result if executed once or multiple times
Difference between Promise.prototype.resolve and resolving within the executor function?
Both return Promises themselves -- need to figure this one out.. Some believe it to be syntactic sugar.
What are two applications of the Gayle-Shapley Stable Matching algorithm?
College admissions, Hospital-patient matching
What is meant when something is the inverse of something else?
Define inverse: a reciprocal quantity, mathematical expression, geometric figure, etc., that is the result of inversion. an element that, when combined with a given element in an operation, produces the identity element for that operation. Intuitively, the opposite of something.
Describe the bottom-up method
Depends on a natural notion of the "size" of a subproblem s.t. solving any particular subproblem only depends on solving "smaller" subproblems: 1.. sort the s.p. by size 2. solve them in size order smallest first 3. solve each subpproblem only once, which we first see it, we have already solved all of its previous subproblems.
Checklist for web typography: Content
Did you... Check spelling, grammar, and sentence structure? Limit the use of exclamation points? (Just don't use them - steve) Specify proper typographic characters, including en dash, em dash, curly quotes, true ellipse, and upper and lowercase numerals?
Checklist for web typography: Graphic
Did you... Make use of graphic text only when absolutely necessary, to avoid excessive download times? Choose appropriate embellishment, anti-aliasing, and kerning? For very small text, use typefaces designed for a specific size and turn off anti-aliasing?
Checklist for web typography: Typefaces:
Did you... Use a non-decorative, screen-optimized typeface at a legible size for body copy? Use looser leading appropriately for longer lines of text, for emphasis, or to lighten the density of the page? Use wider letter and word spacing for emphasis? Set body copy as justified left, ragged right? Employ contrasting elements like different typefaces, size, weight, color, form, structure, bold, italic, reversing the type and background colors, all caps, texture, direction, rhythm, spacing, and embellishment to emphasize special areas of type? Use restraint on those elements just listed? Make use of CSS to set special capitalization rules (all uppercase, all lowercase, title case) automatically? *Avoid using all caps in body text?* *Apply underlining only for links?* Test the site in grayscale to make sure that foreground text contrasts sufficiently in value with background text? If using light text on a dark background, consider making the text bolder or choosing a typeface with inherently thicker strokes? Avoid strikethrough like this unless you are attempting to display edited versions of documents? Consider using CSS to style the first-letter or first-line of text for decorative effect?
David Deida - Way of the Superior Man (Chapter 1 26:27) - All efforts ___. The superior man is always ____ and ____ __.
Dissolve. The superior man is always giving and letting go. Whatever you build will fall aprt. Whatever relationships you have will be destroyed. Everything you give is only light dissolving into its sources consciousness.
position: absolute
Do not leave space for the element. Instead, position it at a specified position relative to its closest positioned ancestor if any, or otherwise relative to the initial containing block. Absolutely positioned boxes can have margins, and they do not collapse with any other margins.
How do you convert CFLs into CFGs? Answer generally.
First, many CFLs are the union of simpler CFLs. If you must construct a CFG for a CFL that you can break into simpler pieces, do so and then construct individual grammars for each piece. These individual grammars can be easily merged into a grammar for the original language by combining their rules and then adding the new rule S → S1 | S2 | ··· | Sk, where the variables Si are the start variables for the individual grammars.
What is a direct-mapped cache?
N-sets in a cache, 1-way. There is one spot, for each block to be stored. A cache block can only go in one spot in the cache. It makes a cache block very easy to find, but it‛s not very flexible about where to put the blocks.
What is a fully associative cache?
N-ways in a cache. 1 set (or no sets really..) No index is needed, since a cache block can go anywhere in the cache. Every tag must be compared when finding a block in the cache, but block placement is very flexible! There are n-ways to store a block. http://csillustrated.berkeley.edu/PDFs/handouts/cache-3-associativity-handout.pdf
What are the different flavors of outputted CSS that SASS can export? How can SASS help you debug?
NESTED, EXPANDED, COMPACT, COMPRESSED There are also options to output CSS with line numbers for respective SASS files.
**Should you use specificity child selectors for jquery?** $("#parent > .child").show();
Nah, use .find or other chainable selectors because its optimized and doesnt go through the whole DOM
Why is array search O(n)?
Need to find that element by checking each element of the array which grows with the size of the array.
DVIS: Steven's 4 scales of measurement? Name some examples and also the math
Nominal select from unorganized set (enumerated type, in C) apples, oranges, tomatoes, ... Toyota, Ford, Subaru, ... Ordinal ordered set of values (< operator available) January, February, March, ... Trial 1, Trial 2, Trial 3, ... 12 Oak St., 125 Oak St., 129 Oak St., ... Interval values are meaningful, but zero is arbitrary (+, - avail.) degrees Celsius position potential energy Ratio values are meaningful, meaningful zero (×, ÷ avail.) degrees Kelvin length mass
NOR Gate?
Inverter(NOT) + AND
XNOR Gate?
Inverter(NOT) + XOR
How do you represent NAN in floating point IEEE754?
If exponent=255 and mantissa is nonzero, then V=NaN ("Not a number") 0 11111111 00000100000000000000000 = NaN 1 11111111 00100010001001010101010 = NaN
**What are the function parameters of the Promise constructor?**
It accepts a typically anonymous function, executor. The executor passes other functions via arguments resolve and reject. new Promise( /* executor */ function(resolve, reject) { ... } );
How do different ISA's differ?
Opcodes - what Operands - who Instruction processing style - 3 addresses, 0 addresses? Instruction addressing modes # of registers I/O interface Instruction length, uniform/non-uniform decoding
**What is a workaround for getting more concurrent connections?**
Open connections to subdomains, different hosts. Think CDNs. [LINK](http://stackoverflow.com/questions/985431/max-parallel-http-connections-in-a-browser)]
How does the shortest path problem demonstrate optimal substructure?
Optimal Substructure: In computer science, a problem is said to have optimal substructure if an optimal solution can be constructed efficiently from optimal solutions of its subproblems. This property is used to determine the usefulness of dynamic programming and greedy algorithms for a problem. What is the shortest path from Seattle to L.A.? If the path also crosses throug h portland and Sacramento, then the shortest route for portland to LA must pass through sacramento too.
Given routine 1 and routine 2, what property should they have to be able to execute w pthreads?
Organizable into discrete, independent tasks, that can execute concurrently. They should be able to be interchanged, interleaved, and or overlapped in real time.
O
Oscar (OSS-CAH)
Convert this to a CFG: {0n1n|n ≥ 0}∪{1n0n|n ≥ 0},
S → S1 | S2 S1 →0S11|ε S2 →1S20|ε Start by breaking the union up and working each piece.
What are the mac address fields in 802.11?
SA: source address - source of the data (MSDU) -> STA1 TA (Transmitter Address): STA that transmitted the frame -> STA1, AP1, AP2 RA (Receiver address): immediate recipient of the frame -> AP1, AP2, STA2 BSSID (Basic Service Set ID): Unique ID of BSS -> eg MAC of AP in finfra network -> AP1, AP2
SCSS, SASS, CSS how do they relate?
SCSS is always valid CSS? nah CSS is always valid SCSS? ye SASS is always valid CSS? nah is SCSS valid SASS? nah is SASS valid SCSS? nah
kill signals: 1,2,15,18,19,20
SIGHUP : 1 - configure reload without termination; also used to report termination of controlling process SIGINT : 2 - cause program to terminate SIGQUIT : 3 - when a user requests to quit a process SIGKILL : 9 - immediately terminate process SIGTERM : 15 - send request to terminate process; request can be interpreted or ignored SIGCONT : 18 - restart previously stopped process SIGSTOP : 19 - stop a process for later resumption SIGTSTP : 20 - send by terminal to request a temporary stop
In Babel and the general JS ecosystem what is the difference between a polyfill and a shim?
So while shims are used for covering up old sins, polyfills are used for bringing future enhancements back in time.
whats a stacking context?
Stacking context is the three-dimensional conceptualization of HTML elements along an imaginary z-axis relative to the user who is assumed to be facing the viewport or the webpage. HTML elements occupy this space in priority order based on element attributes.
How do you construct CFGs for languages that are regular? Answer generally.
Start off by converting creating a DFA from the regular language, then convert it into a CFG. Do so by... 1. Make a variable R_i for each state q_i. 2. If δ(q_i, a) = q_j, then add the rule R_i -> aR_j to the CFG. 3. Add the rule Ri → ε if q_i is an accept state of the DFA. 4. Make R0 the start variable of the grammar, where q0 is the start state of the machine. 5. Verify
Why is F in the 5-tuple describing FA's different from the start state?
Start state is singular, F is a subset of Q (set of states).
**Example of CSRF?**
Steal a cookie (session hijacking) by hosting a malicious website that has a hidden form to another website.
Difference between terminal symbols and nonterminal symbols?
Terminal symbols are the elementary symbols of the language defined by a formal grammar. Nonterminal symbols (or syntactic variables) are replaced by groups of terminal symbols according to the production rules. The terminals and nonterminals of a particular grammar are two disjoint sets.
Line-height
That's exactly what line-height is, it's a manual way to set the height of a line of text for the purposes of wrapping text and such. The actual visible size is determined by the font-size and to a lesser extend by the font-family. The average line-height for normal text/font is around 1.2em. Anything larger than that will cause visible letterboxing, which is exactly what you are describing. Using a smaller value will cause successive lines to overlap each other. The only way to fix your exact example is introduce more markup to determine line numbers so that you can style the first/last line differently.
Explain the color problem and its solution
Most websites only use a handful of colors. When attempting to change one of the colors in a websites main palette - CSS makes you search and replace each one - how could you possibly change one of these palette colors throughout the whole website? SASS variables is the solution.
Python Tuples vs Lists?
Tuples are immutable and fixed size, Lists are mutable and dynamic Convention says to use Tuples for heterogeneous collections, whereas Lists are not so much
What is a 2-way set associative cache?
Two blocks/lines per set. Two ways. There are two spots for each block to be stored. This cache is made up of sets that can fit two blocks each. The index is now used to find the set, and the tag helps find the block within the set.
**What are the five data structures in redis?**
Strings, hashes, lists, sets, ordered sets
bijective functions are...
Surjective + injective -- preserves distinctiveness and all codomain vals are mapped. Bijective means both Injective and Surjective together. So there is a perfect "one-to-one correspondence" between the members of the sets. (But don't get that confused with the term "One-to-One" used to mean injective).
Treat text as a ...
User Interface https://www.subtraction.com www.google.com Think of how text shapes your website and layout. It IS the interface. It's not just content.
How do page faults work?
User writes to memory location, but isn't in memory. So we have to grab the page from disk -- this is done by going into kernel mode, getting that page from disk to memory then re-executing. Page faults often return back to current instruction or abort.
What is the link-local address?
Uses fe80::/10 -- specific to the local network, not routable across networks. These addressees are used on a single link.
Are A and B Concurrent?
Yes! Concurrent: A & B, A & C Sequetional: B & C
What is the difference between SASS and SCSS
every CSS stylesheet is valid SCSS run $sass-convert or $sass to convert between the types mixins are shorter by using + instead of @include indentation instead of brackets
Never take girls advice...
from girls
Proving contrapositive
if H then C, -> if NOT C then NOT H
Explain lsof -i
list open files Open files in the system include disk files, named pipes, network sockets and devices opened by all processes. One use for this command is when a disk cannot be unmounted because (unspecified) files are in use. The listing of open files can be consulted (suitably filtered if necessary) to identify the process that is using the files. The -i option selects the listing of files any of whose Internet address matches the address specified in i. If no address is specified, this option selects the listing of all Internet and x.25 (HP-UX) network files.
**How to copy an object in JS?**
lodash.clone - for shallow copy - shallow copy just copies the elements lodash.deepClone - for deep copy - recursively copies until val is hit
Automata dictionary def. and the purpose of Automata
machine that follows predetermined sequence of ops.
David Deida - Way of the Superior Man (Chapter 1, 16:57) - When we identify with consciousness we are ... when with the life force of the world we feel the ...
masculine, feminine
STAT244: In R make a matrix 3 rows high, 4 cols wide, w/ all fields equalling 0.
matrix(0,3,4)
D3 FEM Points: What is the callback to selection.attr expecting?
selection.attr(name[, value]) <> If a value is specified, sets the attribute with the specified name to the specified value on the selected elements and returns this selection. If the value is a constant, all elements are given the same attribute value; otherwise, if the value is a function, it is evaluated for each selected element, in order, being passed the current datum (d), the current index (i), and the current group (nodes), with this as the current DOM element (nodes[i]). The function's return value is then used to set each element's attribute. A null value will remove the specified attribute.
D3 FEM: selection.data?
selection.data([data[, key]]) <> Joins the specified array of data with the selected elements, returning a new selection that represents the update selection: the elements successfully bound to data. Also defines the enter and exit selections on the returned selection, which can be used to add or remove elements to correspond to the new data. The specified data is an array of arbitrary values (e.g., numbers or objects), or a function that returns an array of values for each group. When data is assigned to an element, it is stored in the property __data__, thus making the data "sticky" and available on re-selection.
STAT244: How to shape a vector into a matrix in R?
dim(vec) <- c(2,4)
R ◦ ∅ ... (important)
may not equal R. For example, if R = 0, then L(R) = {0} but L(R ◦ ∅) = ∅.
Given that A' is the transpose of matrix A. What is (A+B)'
A' + B'
D3 FEM: X,Y goes in which directions in D3?
X goes L->R Y goes Top to Bottom
What do write allocate and no write allocate reference?
What to do on a write miss.
0xE
14
0xFF
255
Elliot Hulse Qualities
Decisive Devoted Disciplined
Name 10 shittests
* jealousy * therapist conversion * "you're a player!" * negs * making you do things e.g. by drinks, * ultimatums (either them or me) * boyfriending * marriage * ignoring * girl freeze outs - being late * unsure about feelings * hitting the bathroom then taking forever * demanding to spend more time together * "you say that to all the girls" * "why?" * "you just want to .. me"
What is a portal, BSS, AP, STA, Distribution SYstem, ESS in 802.11?
* network station (STA) - terminal with access mechanisms to the wireless medium and radio contact to the access point. * access point (AP) - station integrated into the WLAN and the distributed system * basic service set (BSS) - group of stations using the same AP * portal - bridge to other (wired) networks * distribution system - interconnection network to form one logical network (ESS) based on several BSS
Why are processes important?
**Abstraction 1:** Logical control flow: You get the illusion that each program seems to have exclusive use of CPU (this is done via context switching) **Abstraction 2:** Private address space: Each program seems to have exclusive use of main memory. Provided by kernel mechanism called virutal memory.
**What are the five things that the "new" keyword does?**
**What are the four things that the "new" keyword does?** //1. Create a new object //2. Set the prototype //3. Exectute constructor with "this" //4. Return the created object //5. If the constructor, however, returns an object itself, then that is the one that is returned It creates a new object. The type of this object, is simply object. It sets this new object's internal, inaccessible, [[prototype]] (i.e. __proto__) property to be the constructor function's external, accessible, prototype object (every function object automatically has a prototype property). It makes the this variable point to the newly created object. It executes the constructor function, using the newly created object whenever this is mentioned. It returns the newly created object, unless the constructor function returns a non-null object reference. In this case, that object reference is returned instead.
STAT244: is R 0 index based or 1 index based?
1 index based
How do you convert a float to binary?
1. Convert the absolute value of the number to binary, perhaps with a fractional part after the binary point. This can be done by converting the integral and fractional parts separately. The integral part is converted with the techniques examined previously. The fractional part can be converted by multiplication. This is basically the inverse of the division method: we repeatedly multiply by 2, and harvest each one bit as it appears left of the decimal. 2.Append × 20 to the end of the binary number (which does not change its value). 3. Normalize the number. Move the binary point so that it is one bit from the left. Adjust the exponent of two so that the value does not change. 4. Place the mantissa into the mantissa field of the number. Omit the leading one, and fill with zeros on the right. 5. Add the bias to the exponent of two, and place it in the exponent field. The bias is 2k−1 − 1, where k is the number of bits in the exponent field. For the eight-bit format, k = 3, so the bias is 23−1 − 1 = 3. For IEEE 32-bit, k = 8, so the bias is 28−1 − 1 = 127. Set the sign bit, 1 for negative, 0 for positive, according to the sign of the original number.
How is time-travelling possible in elm? Define in 3 Reasons
1. Due to pure functions, functions can be "replayed" safely. 2. All input sources to an elm program are known statically at compile time. You declare that your game expects keypressed and mouse clicks. This makes inputs easy to track. So we record ethe history of inputs. 3. Elm programs might have state, but that state is stored by the runtime, not the program, thus reactor can jump to any state because this internal state is determined entirely by recorded input events.
Name the five invariants of a red-black tree and what critical property they enforce.
1. Each node is either red or black. 2. The root is black. This rule is sometimes omitted. Since the root can always be changed from red to black, but not necessarily vice versa, this rule has little effect on analysis. 3. All leaves (NIL) are black. 4. If a node is red, then both its children are black. 5. Every path from a given node to any of its descendant NIL nodes contains the same number of black nodes. Some definitions: the number of black nodes from the root to a node is the node's black depth; the uniform number of black nodes in all paths from root to the leaves is called the black-height of the red-black tree. The path from the root to the farthest leaf is no more than twice as long as the path from the root to the nearest leaf
How does extraction work in binary heaps?
1. Extract root and swap with rightmost **leaf** 2. Compare new root with children; if correct order, stop 3. If not, swap elements downwards. NOTE: what do i do if the tree is no longer complete?
What are the process states?
1. Running - CPU is running instructions A process moves into the running state when it is chosen for execution. The process's instructions are executed by one of the CPUs (or cores) of the system. There is at most one running process per CPU or core. A process can run in either of the two modes, namely kernel mode or user mode.[1][2] 2. Waiting - 3. Sleeping - A process is sleeping when it is blocked, waiting for something. For example, it might have called read() and is waiting on data to arrive from a network stream. sleep() is indeed one way to have your process sleep for a while. Sleeping is, however, the normal state of all but heavily compute-bound processes - sleeping is essentially what a process does when it isn't doing anything else. It's the normal state of affairs for most of your processes to be sleeping - if that's not the case, it tends to indicate that you need more CPU horsepower. 4. Stopped - 5. Zombie
CLRS says there are two equivalent ways to implement a dp algo. Describe them.
1. Top-down w/ memoization 2. Bottom-up method
What types of programs are well suited for threading? (name 5)
1. Work that can be executed, or data that can be operated on, by multiple tasks simultaneously: 2. Block for potentially long I/O waits 3. Use many CPU cycles in some places but not others 4. Must respond to asynchronous events 5. Some work is more important than other work (priority interrupts)
Why does Array.apply(null,Array(5)).map(Number.prototype.valueOf,5) work?
1. create a non-sparse array using Array.apply that is iterable 2. pass null as this arg, then map using this val as 5 to get valueof it.
Javascript: Name 6 ways to iterate over a JS object
1. for in construct -> own and inherited, check with .hasOwnProperty Note that you can use .forEach chaining for more flexible looping 2. Object.keys -> own enumerable 3. Object.entries -> own enumerable 4. for... of loops?? -> loops over iterable collections 5. Object.getOwnPropertyNames -> enumerable or not 6. Object.values
What are the 4 steps of a greedy stays ahead proof for ISMP?
1. label algos partial solutions and a general solution. 2. Find a heuristibc by which greedy stays ahead of highest # of intervals a general/optimal solution. 3. Show that greedy stays ahead by induction 4. Prove optimality.
Give 3 examples of threading?
1. manger/worker 2. peer 3. pipeline
**The promise's .then() accepts what paramters?**
1. onFulfilled (function) - value 2. onRejected (function) - reason
According to Kyle Simpson, how does a Promise Instill Trust? Name 5 Key points
1. only resolved once 2. either success or error 3. messages passed or kept 4. exceptions beceome errors 5. immutable once resolved
What things does a process contain (Name 11)
1. pid, pgid, uid, gid 2. environment 3. working directory 4. program instructions 5. registers 6. stack 7. heap 8. file descriptors 9. signal actions 10. shared libraries 11. interprocess communications
How long is an IPv6 Address?
8 groups of 4 hex digits, each group represents 16 bits or 2 octets, 128 bits in total
2⁸-1
255
2⁸
256
How many characters in ASCII including extended ASCI?
256
How many subnets in...
2^8-2
4,294,967,296 four billion, two hundred ninety four million, nine hundred sixty seven thousand, two hundred ninety six
2³²
2,147,483,647 - two billion one hundred forty seven million, four hundred eighty three thousand, six hundred forty seven
2³¹ - 1, 32 bit signed binary integer, thus this is MAX INT for 4 byte integers. Some interesting traits - largest known prime for a while. 0x7FFFFFFF euler proved the primality of it.
127
2⁷ - 1
How does IEEE754 break down the floating point bytes for a float in C?
32 bits 1 sign bit, 8 exponent bits, 23 mantissa bits
2¹⁵
32768
What number has two 1s in the middle
6
Soft boiled egg time in boiling water?
6 minutes
What is A in ASCII?
65 - 100001
**Uppercase letters in ASCII start and end?**
65-90
How many bits are used in standard ASCII?
7 meaning 2^7 = 128
Why are IP addresses limited to 255 in Ipv4
8 bits 2^8-1 = 255
What numbers have 1s aligned from left to right
8, 12, 14, 15
What is a promise?
A Promise is a proxy for a value not necessarily known when the promise is created. It allows you to associate handlers to an asynchronous action's eventual success value or failure reason. This lets asynchronous methods return values like synchronous methods: instead of the final value, the asynchronous method returns a promise for the value at some point in the future.
Given that A' is the transpose of matrix A. What is (A')' ?
A (involution)
Shorten the following: A -> 0A1 A -> B
A -> 0A1 | B
CPU vs microprocessor?
A CPU (central processing unit) is the part of a computer that executes instructions. This can be implemented using a single IC, a number of ICs, discrete transistors or a room full of vacuum tubes. A microprocessor is a single-chip implementation of a CPU.
What is a ESS in 802.11?
A ESS is the extended SS. This can be the amalgamation of two or more interconnected wireless BSSs that share the same SSID, credentials and integrated wLANS that appear as a isngle BSS to the logical layer. e.g. UChicago WIFI is a ESS.
What is a binary heap really?
A binary heap is a binary tree with two additional constraints: 1. Shape property: a binary heap is a complete binary tree; that is, all levels of the tree, except possibly the last one (deepest) are fully filled, and if the last level is not complete then nodes are filled left to right. 2. Heap property: the key stored in each node is either greater than or equal to (≥) or less than or equal to (≤) the keys in the node's children, according to some total order.
Difference between buffers and caches?
A cache often also acts as a buffer, and vice versa. However, caches operate on the premise that the same data will be read from them multiple times, that written data will soon be read, or that there is a good chance of multiple reads or writes to combine to form a single larger block. Their sole purpose is to reduce accesses to the underlying slower storage. A cache is also usually an abstraction layer that is designed to be invisible. A "Disk Cache" or "File Cache" keeps statistics on the data contained within it and commits data within a time-out period in write-back modes. A buffer does none of this. A buffer is primarily used for input, output, and sometimes very temporary storage of data that is either en route between other media or data that may be modified in a non-sequential manner before it is written (or read) in a sequential manner. Buffers are usually used in a FIFO (first in, first out) method, outputting data in the order it arrived.
What is reentrancy in computer science?
A computer program or subroutine is called reentrant if it can be interrupted in the middle of its execution and then be safely called again ("re-entered") before its previous oinvocations completely executes.
What is the Chomsky Normal Form?
A context-free grammar is in Chomsky normal form if every rule is of the form A → BC A→a where a is any terminal and A, B, and C are any variables—except that B and C may not be the start variable. In addition, we permit the rule S → ε, where S is the start variable.
STAT244: Correlation vs Covariance?
A correlation coefficient measures the extent to which two variables tend to change together. The coefficient describes both the strength and the direction of the relationship. Covariance measures the linear relationship between two variables. Covariance is not standardized, unlike the correlation coefficient. Therefore, covariance values can range from negative infinity to positive infinity. Positive covariance values indicate that above average values of one variable are associated with above average values of the other variable and below average values are similarly associated. Negative covariance values indicate that above average values of one variable are associated with below average values of the other variable. A correlation coefficient is the covariance divided by the product of each variable's standard deviation Although both the correlation coefficient and the covariance are measures of linear association, they differ in the following ways: Correlations coefficients are standardized. Thus, a perfect linear relationship results in a coefficient of 1. Covariance values are not standardized. Thus, the value for a perfect linear relationship depends on the data. The correlation coefficient is a function of the covariance. The correlation coefficient is equal to the covariance divided by the product of the standard deviations of the variables. Therefore, a positive covariance always results in a positive correlation and a negative covariance always results in a negative correlation.
what is the point of a finite automaton?
A finite automaton (FA) is a simple idealized machine used to recognize patterns within input taken from some character set (or alphabet) C. The job of an FA is to accept or reject an input depending on whether the pattern defined by the FA occurs in the input
What is a heap?
A heap is a special tree structure (ADT) where the elements are "partially sorted" and satisfies the heap property -- the key stored in each node is either greater than or equal to or less than or equal to the keys in the node's children, according to some total order. Thus, heap's typically allow find-min or find-max to be O(1) time.
What is bigger, a language or an alphabet?
A language is a subset of an alphabet *. A formal language L over an alphabet Σ is a subset of Σ*, that is, a set of words over that alphabet
A language is called regular if...
A language is called a regular language if some finite automaton recognizes it.
What is the difference between a microprocessor and a microcontroller?
A microprocessor is typically a SINGLE CHIP implementation of a CPU. A Microcontroller is a Full system on a chip.
What is a recursive or inductive definition?
A recursive definition (or inductive definition) in mathematical logic and computer science is used to define the elements in a set in terms of other elements in the set (Aczel 1978:740ff). A recursive definition of a function defines values of the functions for some inputs in terms of the values of the same function for other inputs. For example, the factorial function n! is defined by the rules 0! = 1. (n+1)! = (n+1)·n!. This definition is valid for all n, because the recursion eventually reaches the base case of 0. The definition may also be thought of as giving a procedure describing how to construct the function n!, starting from n = 0 and proceeding onwards with n = 1, n = 2, n = 3 etc..
What is a string or word?
A string or word is a finite sequence of symbols from an alphabet
What is a structural hazard/dependency?
A structural hazard occurs when a part of the processor's hardware is needed by two or more instructions at the same time. A canonical example is a single memory unit that is accessed both in the fetch stage where an instruction is retrieved from memory, and the memory stage where data is written and/or read from memory.[3] They can often be resolved by separating the component into orthogonal units (such as separate caches) or bubbling the pipeline.
What is a theorem?
A theorem is a statement that can be demonstrated to be true by accepted mathematical operations and arguments. In general, a theorem is an embodiment of some general principle that makes it part of a larger theory. The process of showing a theorem to be correct is called a proof.
Let the alphabet Σ be the standard 26 letters {a, b, . . . , z}. If A = {good, bad} and B = {boy, girl}, define A ∪ B, AB, and A*
A ∪ B = {good, bad, boy, girl}, A ◦ B = {goodboy, goodgirl, badboy, badgirl}, and A∗ = {ε, good, bad, goodgood, goodbad, badgood, badbad, goodgoodgood, goodgoodbad, goodbadgood, goodbadbad, . . . }.
**What does the logarithmic function graph look like?** What happens as log base decreases or increases?
All intersect x axis at 1 Steeper ascent for lower log bases
If we query www.google.com what type of record do we get back?
AAAA record (Quad-A(address) record))
What is row-echelon form?
All nonzero rows (rows with at least one nonzero el) are above any rows of all zeroes. 2. Pivots are alway sto the right?
Ethernet is a Layer 2 Protocol, and so is ARP. However, Ethernet frames have an Ethertype header that indicates the protocol being used at the data-link layer such as ARP or IPv4. Is this a misnomer then? Is ARP a protocol OF ethernet and OF the data-link layer or is this more for labelling convenience purposes or legacy reasons. Edit: To clear up any potential confusion to what I'm asking: IEEE 802.11 has a separate frame type that it sends and is also a Layer 2 Protocol, but it is not OF Ethernet, and there is no EtherType to represent it (from what I know). Why isn't there a separate ARP frame then instead of it being nested into an Ethernet frame?
ARP is a protocol that operates solely within a single network connected by the same data link, and it does not provide any of the functionality that a Network Layer protocol does (most notably, the ability to route between networks). So, its correct place is the Data Link layer. More generally, just because a protocol X is the payload of a Layer N protocol doesn't mean that protocol X is in layer N+1. The layer is determined by the kind of functionality provided by the protocol. A similar example is ICMP: it is the payload of IP but it is not a Transport Layer protocol; it's still a Network-layer protocol. Ethernet and 802.11 are different protocols, both at the same layer, both with (very broadly) the same purpose: to carry a payload within a given data link. While it is technically possible to tunnel 802.11 through Ethernet and viceversa (meaning that you could potentially have an 802.11 frame as the payload of an Ethernet frame, and viceversa), that is more of a corner case. First and foremost, you will either have an Ethernet network or an 802.11 network, and you will use the frame format appropriate to that network. So, in an 802.11 network, ARP requests are simply carried as the payload of an 802.11 data frame. Finally, take into account that Ethertypes don't show up in 802.11 networks because they use a different mechanism to determine the type of the payload. Ethernet has an Ethertype field in the frame header, whereas 802.11 relies on the presence of a SNAP header at the beginning of the payload of a data frame.
What is the special functionality of IDs?
Ability to scroll. If you have a URL like http://yourdomain.com#comments, the browser will attempt to locate the element with an ID of "comments" and will automatically scroll the page to show that element. This won't work for classes obviously so the browser knows where to scroll.
Name the main states for both active and passive openers in the 3-way handshake.
Active: CLOSED -> SYN_SENT -> ESTABLISHED Passive: CLOSED -> LISTENING -> SYN_RCVD -> ESTABLISHED
Main components of CPU?
Arithmetic Logic Unit (ALU), Control Unit (CU), Cache
LDV Chant
Artistry, dedication, hard work, mission, mastery
Often column vectors are represented as row vectors how?
As the transpose of a row vector.
Associative property
Associative - formally: (x ∗ y) ∗ z = x ∗ (y ∗ z) for all x, y, z in S. The associative law can also be expressed in functional notation thus: f(f(x, y), z) = f(x, f(y, z)). So, associativity is more about using an operator Within an expression containing two or more occurrences in a row of the same associative operator, the order in which the operations are performed does not matter as long as the sequence of the operands is not changed. That is, rearranging the parentheses in such an expression will not change its value. Consider the following equations: (2+3) + 4 = 2 + (3 + 4) = 9 2 X (3 X 4) = (2 X 3) X 4 = 24
CMYK
CMYK (cyan, magenta, yellow, key(black))is a subtractive, reflected light color system. All colors start with white "paper", to which different color "inks" are added to absorb (subtract) light that is reflected. In theory, CMY are all you need to create black (applying all 3 colors at 100%). Alas, that usually results in a muddy, brownish black, so the addition of K (black) is added to the printing process. It also makes it easier to print black text (since you don't have to register 3 separate colors). Most printers print in CMYK color (though some photo printers will print with expanded colors beyond those 4). Expressed with 0-100%
ul li
COMBINATOR: descendant selector The ' ' combinator selects nodes that are children (not necessary direct children) of the former specified element.
What problems does SMACSS attempt to solve?
Categorization of CSS Naming convention of CSS Decoupling of CSS State-based design Intuition: Allows for recognition of reusable modules and styling.
How to test for injective functions?
Charging argument or horizontal line test (should never pass two) -- preserves distinctiveness
Edward Treacher Collins - Arboreal Locomotion Hypothesis
Collins' idea has become known as the "arboreal locomotion hypothesis" - arboreal meaning living in trees. In the decades since, it has been expanded and refined, but the basic idea that our ancestors evolved forward facing eyes to accurately judge distances while leaping from tree to tree remained central for quite a while. After all, the stakes for failing to work out the true distance between trees were high. "The price of failure was to drop many metres onto a ground inhabited by carnivorous beasts," wrote visual psychotherapist Christopher Tyler in 199
What are the CSS problems that SASS and preprocessors help you deal with?
Color problem, duplication problem, cascade problem, calculation problem, importing problem.
Bijective functions are...
Combination of 1 to 1 and onto. Each element of one set is paired with exactly one element fo the other set and vice versa.
In 802.11, Frame Control has two bits ToDS, FromDS, bits are both = 0. What does that mean
Coming from a STA going to another STA on the same BSS. Other examples: To DS field is 1 and From DS field is 0 To DS field is 0 and From DS field is 1
CBNZ CBZ
Compare and branch if nonzero Compare and branch if zero p435 Compare and branch if zero to a label at a PC-relative offset, without affecting the condition flags, and with a hint that this is not a subroutine call or return
What is a charging argument?
Compare output of an optimization algorithm to an optimal soluition -- to usually show existence of an injective function.
What does it mean to flush the buffer?
Consider writing to a file. This is an expensive operation. If in your code you write one byte at a time, then each write of a byte is going to be very costly. So a common way to improve performance is to store the data that you are writing in a temporary buffer. Only when there is a lot of data is the buffer written to the file. By postponing the writes, and writing a large block in one go, performance is improved. With this in mind, flushing the buffer is the act of transferring the data from the buffer to the file. Does this clear the buffer by deleting everything in it or does it clear the buffer by outputting everything in it? The latter. A buffer flush is the transfer of computer data from a temporary storage area to the computer's permanent memory (not exactly, but sometimes). Here's one example of a buffer flush: When you make changes in a Word document, the changes you see on your computer screen are stored temporarily in a buffer. When you save your work, the changes that you've made to your document since the last time you saved it are flushed from the buffer to permanent storage on the hard disk.
Object.entries() var obj = { foo: "bar", baz: 42 }; console.log(Object.entries(obj)); var obj = { 0: 'a', 1: 'b', 2: 'c' }; console.log(Object.entries(obj));
ES2017 (Draft) The Object.entries() method returns an array of a given object's own enumerable property [key, value] pairs, in the same order as that provided by a for...in loop (the difference being that a for-in loop enumerates properties in the prototype chain as well). Object.entries() returns an array whose elements are arrays corresponding to the enumerable property [key, value] pairs found directly upon object. The ordering of the properties is the same as that given by looping over the property values of the object manually. // [ ['foo', 'bar'], ['baz', 42] ] // [ ['0', 'a'], ['1', 'b'], ['2', 'c'] ]
So waht is a context switch really?
Just a CPU/Registers changing the memory values and the egister alues for a porcess.
Difference between a DFA and NFA?
Each input to a DFA or NFA affects the state of the automaton: if it was in state qq immediately before the input, either it will be in some state q′q′ after the input, or the input will cause it to choke. (Note that q′q′ may be the same as qq.) Suppose that we have an automaton in a state qq. The difference in behavior between a DFA and an NFA is this: If it's a DFA, each possible input determines the resulting state q′q′ uniquely. Every input causes a state change, and the new state is completely determined by the input. Moreover, the automaton can change state only after reading an input. If it's an NFA, some inputs may allow a choice of resulting states, and some may cause the automaton to choke, because there is no new state corresponding to that input. Moreover, the automaton may be constructed so that it can change state to some new state q′q′ without reading any input at all. As a consequence of this difference in behavior, DFA's and NFA's differ in another very important respect. If you start a DFA in its initial state and input some word ww, the state qq in which the DFA ends up is completely determined by ww: inputting ww to the DFA will always cause it to end up in state qq. This is what is meant by calling it deterministic. If you start an NFA in its initial state and input some word ww, there may be several possible states in which it can end up, since some of the inputs along the way may have allowed a choice of state changes. Consequently, you can't predict from ww alone in exactly which state the automaton will finish; this is what is meant by calling it nondeterministic. (And it's actually a little worse than I've indicated, since an NFA is also allowed to have more than one initial state.) Finally, these differences affect how we determine what words are accepted (or recognized) by an automaton. If it's a DFA, we know that each word completely determines the final state of the automaton, and we say that the word is accepted if that state is an acceptor state. If it's an NFA, there might be several possible final states that could result from reading a given word; as long as at least one of them is an acceptor state, we say that the automaton accepts the word. What I've described informally is the view of an NFA that makes it look most like a DFA and that I think best explains why it's called nondeterministic. There is, however, another way of looking at NFAs: it's also possible to think of an NFA as being in multiple states at once, as if it were making all possible choices at each input. If you think of it in those terms, you can say that it accepts a word provided that at least one of the states in which it ends up after reading that word is an acceptor state. This point of view is perhaps most useful for understanding the algorithm used to turn an NFA into an equivalent DFA.
What are some examples of stages in the RISC pipeline can use data forwarding?
Execute to memory access of another stage. Writeback to Execute of another stage. Forward data from Writeback(WB) to Execute (EX) stage. It might happen that an instruction is at WB stage and wants to update the value of a register. In the same time, another instruction is at the EX stage and want to use the value of the same register. Here we want you to implement your simulator in a way that the updated value is forwarded to EX stage from WB stage. Here is an example. 1)adds X8, X1, 0x1 2)adds X19, X2, 0x2 3)adds X11, X8, 0xff When instruction 1 is at WB stage, instruction 3 is at EX stage and we can forward the value of register X8 from WB to EX stage. Forward data from Memory Access(MEM) to Execute (EX) stage. Now consider this case, 1)adds X8, X1, 0x1 2)adds X19, X8, 0x2 Here, rst instruction is an "add" and wants to update the value of register X8, and second instruction wants to use the value of register X8. When rst instruction is at EX stage it calculates the value of register X8, so when this instruction ow through MEM stage the value of register X8 is already calculated and can be forwarded to EX stage where the second instruction needs it.
What is the current state of __proto__?
Exists for legacy reasons. Not recommended to be used but was standardized for ES6.
What is a flip-flop
Flip-flops and latches are used as data storage elements. A flip-flop stores a single bit (binary digit) of data; one of its two states represents a "one" and the other represents a "zero". Such data storage can be used for storage of state, and such a circuit is described as sequential logic. When used in a finite-state machine, the output and next state depend not only on its current input, but also on its current state (and hence, previous inputs). It can also be used for counting of pulses, and for synchronizing variably-timed input signals to some reference timing signal. Flip-flops can be either simple (transparent or opaque) or clocked (synchronous or edge-triggered). Although the term flip-flop has historically referred generically to both simple and clocked circuits, in modern usage it is common to reserve the term flip-flop exclusively for discussing clocked circuits; the simple ones are commonly called latches.[1][2]
Describe the theme category
For on-the-fly style changes Usually unneeded category of SMACSS E.g. Display for non-english languages. Skin applications for Chrome web browser. Used for whitelabelling.
What is overloading?
Function overloading (also method overloading) is a programming concept that allows programmers to define two or more functions with the same name. Each function has a unique signature (or header), which is derived from: function/procedure name. number of arguments. arguments' type.
What is Futura?
Geometric sans-serif. Low x-height surprisingly making it good for body text. Not decorative Extended points. Light, Book, Medium, Heavy, Bold, Extra Bold Light Condensed, Book Condensed, Medium Condensed Bauhaus influenced. Futura is a geometric sans-serif typeface designed in 1927 by Paul Renner. It was designed as a contribution on the New Frankfurt-project. It is based on geometric shapes that became representative of visual elements of the Bauhaus design style of 1919-33.[2][3] It was commissioned as a typeface by the Bauer Type Foundry, in reaction to Ludwig & Mayer's seminal Erbar of 1922.[1] Futura has an appearance of efficiency and forwardness. Although Renner was not associated with the Bauhaus, he shared many of its idioms and believed that a modern typeface should express modern models, rather than be a revival of a previous design. Renner's design rejected the approach of previous sans-serif designs (now often called grotesques), which were based on the models of signpainting, condensed lettering and nineteenth-century serif typefaces, in favour of simple geometric forms: near-perfect circles, triangles and squares. It is based on strokes of near-even weight, which are low in contrast. The lowercase has tall ascenders, which rise above the cap line, and uses a single-story 'a' and 'g,' previously more common in handwriting than in printed text. The uppercase characters present proportions similar to those of classical Roman capitals.
Pete Hunt "Rethinking Best Practices" : PH describes a React Component as... "A ____ building block for UIs ___ with other components" (4 words)
Highly cohesive, loosely coupled.
Temporal locality?
If at one point a particular memory location is accessed, it is likely that the same location will be accessed again in the near future.
Natural: Wolfgang first frame
I deserve the best for myself. I love staying in set. I love maintaining eye contact. Most of all, I love challenges. I love the thrill of this PUA challenge, because it is so fundamental to human life and important to my growth. I like it when I get rejected because it gives me an opportunity to grow. I want to find the connection between myself and another human I want to give my gift to others. I swear that I will never stop improving and continue to challenge myself. I will push my boundaries every single day to become the man I want to be and all the while enjoy the journey. I am my own man, independent, and have a gift to give while working for my highest purpose. I am grateful for all the mistakes I made, I make, and I will make, because my mistakes make who I am. I am NOT perfect, but I deserve a ten, because neither is she and neither is he. I do NOT care what other people think of me. I am to become a master of many things. I love myself because I'm awesome. I'm attractive because: * I'm talented in music/singing/dancing * I'm mission-oriented * I'm interesting * I am my own man * I am athletic * I am disciplined * I am funny * I can be charismatic * I am unselfish * I am street-smart * I am risk-taking * I am unconventional * I am ambitious * I am a genius And most of all, I love myself, and I love my life, and I love this world.
What are unit rules?
I'm assuming they're just rules of the form A -> B
What is the conventional distinction between accept and recognize in automata theory?
If A is the set of all strings that machine M accepts, we say that A is the language of machine M and write L(M) = A. We say that M recognizes A or that M accepts A. However, because the term accept has different meanings when we refer to machines accepting strings and machines accepting languages, we prefer the term recognize for languages in order to avoid confusion.
How do you represent negative infinity and infinity in floating point (IEEE754)?
If E=255 and mantissa is zero and sign is 1, then V=-Infinity 0 11111111 00000000000000000000000 = Infinity 1 11111111 00000000000000000000000 = -Infinity
What does it mean for a grammar to be ambiguous?
If a grammar generates the same string in several different ways, we say that the string is derived ambiguously in that grammar. If a grammar generates some string ambiguously, we say that the grammar is ambiguous. FORMALLY: A string w is derived ambiguously in context-free grammar G if it has two or more different leftmost derivations. Grammar G is ambiguous if it generates some string ambiguously.
Spatial locality?
If a particular storage location is referenced at a particular time it is likely that nearby memory locations will be referenced in the near future.
How do forks relate to node promises when not chained?
If you chain asynchronous function calls via then(), they are executed sequentially, one at a time: asyncFunc1() .then(() => asyncFunc2()); If you don't do that and call all of them immediately, they are basically executed in parallel (a fork in Unix process terminology): asyncFunc1(); asyncFunc2(); So essentially you run asyncFunc1 and 2 concurrently when not chained.
What the hell is a negative zero, does it exist?
In C floats negative zeroes exist. But the standard only says that negative and positive zero must be equal. The semantics of negative zero are well defined by the IEEE-754 standard; the only real observable way in which its behavior differs from that of zero in arithmetic expression is that if you divide by it, you will get a different sign of infinity.
Where do we see a similar pattern to page faults?
In caches.
FP: Lazy v Eager Evaluation
In computer programming, eager evaluation or greedy evaluation is the evaluation strategy used by most traditional programming languages. In eager evaluation, an expression is evaluated as soon as it is bound to a variable. An alternative to eager evaluation is lazy evaluation, where expressions are evaluated only when a dependent expression is evaluated.[clarification needed] Imperative programming languages, where the order of execution is implicitly defined by the structure of the source code, almost always use eager evaluation.[why?] One advantage[clarification needed] of eager evaluation is that it eliminates the need[clarification needed] to track and schedule the evaluation of expressions. It also allows the programmer to dictate the order of execution, making it easier to control when sub-expressions (including functions) within the expression will be evaluated, as these sub-expressions may have side effects that will affect the evaluation of other expressions. Disadvantages of eager evaluation[clarification needed] are that it forces the evaluation of expressions that may not be necessary at run time, and it may delay the evaluation of expressions that have a more immediate need. In imperative languages, it also forces the programmer to organize the source code for optimal order of execution. Conversely, it allows the programmer to order the source code to control the order of execution.
What are buffers?
In computer science, a data buffer (or just buffer) is a region of a physical memory storage used to temporarily store data while it is being moved from one place to another.
**What is Simpson's rule?**
Integral approximation via parabolas
What is lexical analysis?
In computer science, lexical analysis is the process of converting a sequence of characters (such as in a computer program or web page) into a sequence of tokens (strings with an identified "meaning"). A program that performs lexical analysis may be called a lexer, tokenizer,[1] or scanner (though "scanner" is also used to refer to the first stage of a lexer). Such a lexer is generally combined with a parser, which together analyze the syntax of programming languages, web pages, and so forth.
What is locality of reference?
In computer science, locality of reference, also known as the principle of locality, is a term for the phenomenon in which the same values, or related storage locations, are frequently accessed, depending on the memory access pattern.
What is a Message Authentication Code?
In cryptography, a message authentication code (MAC) is a short piece of information used to authenticate a message—in other words, to confirm that the message came from the stated sender (its authenticity) and has not been changed in transit (its integrity).
Regression Analysis: Null Hypothesis
In inferential statistics, the term "null hypothesis" is a general statement or default position that there is no relationship between two measured phenomena, or no association among groups.[1] Rejecting or disproving the null hypothesis—and thus concluding that there are grounds for believing that there is a relationship between two phenomena (e.g. that a potential treatment has a measurable effect)—is a central task in the modern practice of science; the field of statistics gives precise criteria for rejecting a null hypothesis. The null hypothesis is generally denoted H_o
What is a constructive proof?
In mathematics, a constructive proof is a method of proof that demonstrates the existence of a mathematical object by creating or providing a method for creating the object.
What is Dynamic Programming?
In mathematics, management science, economics, computer science, and bioinformatics, dynamic programming (also known as dynamic optimization) is a method for solving a complex problem by breaking it down into a collection of simpler subproblems, solving each of those subproblems just once, and storing their solutions - ideally, using a memory-based data structure. The next time the same subproblem occurs, instead of recomputing its solution, one simply looks up the previously computed solution, thereby saving computation time at the expense of a (hopefully) modest expenditure in storage space. (Each of the subproblem solutions is indexed in some way, typically based on the values of its input parameters, so as to facilitate its lookup.) The technique of storing solutions to subproblems instead of recomputing them is called "memoization".
What does it mean for two sets to be disjoint?
In mathematics, two sets are said to be disjoint if they have no element in common. Equivalently, disjoint sets are sets whose intersection is the empty set.[1]
What is an interface?
In object oriented programming, an interface generally defines the set of methods (or messages) that an instance of a class that has that interface could respond to. collection of operations that are possible on an object of a type.
Regression Analysis: Central Limit Theorem
In probability theory, the central limit theorem (CLT) establishes that, for the most commonly studied scenarios, when independent random variables are added, their sum tends toward a normal distribution (commonly known as a bell curve) even if the original variables themselves are not normally distributed. In more precise terms, given certain conditions, the arithmetic mean of a sufficiently large number of iterates of independent random variables, each with a well-defined (finite) expected value and finite variance, will be approximately normally distributed, regardless of the underlying distribution.[1][2] The theorem is a key concept in probability theory because it implies that probabilistic and statistical methods that work for normal distributions can be applicable to many problems involving other types of distributions.
**What is a leaky abstraction?**
In software development, a leaky abstraction is an abstraction that exposes details and limitations of its underlying implementation to its users that should ideally be hidden away. Leaky abstractions are considered problematic, since the purpose of abstractions is to manage complexity by concealing unnecessary details from the user.
Regression Analysis: What is a z-score?
In statistics, the standard score is the signed number of standard deviations by which the value of an observation or data point is above the mean value of what is being observed or measured. Observed values above the mean have positive standard scores, while values below the mean have negative standard scores. The standard score is a dimensionless quantity obtained by subtracting the population mean from an individual raw score and then dividing the difference by the population standard deviation. This conversion process is called standardizing or normalizing (however, "normalizing" can refer to many types of ratios; see normalization for more). Standard scores are also called z-values, z-scores, normal scores, and standardized variables. They are most frequently used to compare an observation to a standard normal deviate, though they can be defined without assumptions of normality.
What is x-height in typography?
In typography, the x-height or corpus size refers to the distance between the baseline and the mean line of lower-case letters in a typeface. Typically, this is the height of the letter x in the font (the source of the term), as well as the u, v, w, and z. (Curved letters such as a, c, e, m, n, o, r and s tend to exceed the x-height slightly, due to overshoot.) One of the most important dimensions of a font, x-height is used to define how high lower-case letters are compared to upper-case letters.
Describe the State category (SMACSS)
Indicate a javascript dependency The variations of modules based on state Intuition: - on same level as module layout - how does a button change on hover? - states of modals, etc - disabled, active, default states, etc.
CLRS mentions to prove 3 properties of loop invariants, what are they?
Initialization: It is true prior to the first iteration of the loop. Maintenance: If it is true before an iteration of the loop, it remains true before the next iteration. Termination: When the loop terminates, the invariant gives us a useful property that helps show that the algorithm is correct.
Preorder, postorder, inorder traversal orders? Curr, left, right?
Inorder - left, curr, right Preorder - curr, left, right Postorder - left,right, curr
Describe insertion sort, then write it out
Insertion sort is kinda how you organize cards naturally. You have a sorted section and an unsorted section. You move from left to right through the unsorted section but compare from right to left in the sorted section. ``` for i =1 to a.length - 1 element = array[i] j = i while (j > 0 and array[j-1] > element) array[j] = array[j-1] j = j - 1 array[j] = element //insert element here ``` Worst case: \Theta(n^2) Θ(n 2 ). Best case: \Theta(n) Θ(n). Average case for a random array: \Theta(n^2) Θ(n2 ). "Almost sorted" case: \Theta(n) Θ(n).
**How does JSONP prevent same-origin policy?**
It uses the script tag and passes JSON as a function parameter. We need it because you're not allowed to request JSON via AJAX on another domain normally. How does it work?? It really defines a "script" tag to check Javascript of. The javascript there has a function call around JSON data to be returned. This function is named by the caller's environment and is thus called. Essentially, ANOTHER website/server is calling a function defined within a client's environment and thereby calling that function with the data required! Since JSON is a JS object it works!
Some proof of greeks and mind-body connection
It was commonly believed that the mind, body, and soul each had to be developed and prepared for a man to live a life of arete. This led to the thought that athletics had to be present in order to obtain arete. They did not need to consume one's life, merely exercise the body into the right condition for arete, just like the mind and soul would be exercised by other means. (ARETE)
Integrated Circuit
Just think of as synonymous with chip, but these chips are composed of electronic componenets. Integrated circuit vs Discrete circuit.
K
Kilo (KEY-LOW)
What does it mean for a string to be recognized?
L(M) = A, M recognizes A, a set of strings that the machine accepts. Ends up in a final state.
Explain Least Squares Regression
LSR is sum of the errors. e_i = yi^ - yi. Minimize sum of e_i squared. Where we square residuals to ignore sign.
What's the basic idea behind IEEE754 and notation?
Let's use scientific notation but with base two. That is... Significand × 2^exponent
Letterboxing
Letterboxing is the practice of transferring film shot in a widescreen aspect ratio to standard-width video formats while preserving the film's original aspect ratio.
Describe the base category.
Libraries Reset/Normalize Element selectors Intuition: If you're writing CSS that overrides OTHER CSS this should be a warning.
What is a HEAD Request used for?
Like GET, but you can just get back the headers not the payload.
L
Lima (LEE-MAH)
XD: CMD+SHIFT+M
Mask with shape
**What is a MAC?**
Message authentication code - short piece of info used to authenticate a message. It confirms authenticity - that it comes from stated sender and has not been changed in transit.
**what is integrity in security?**
Message has not been changed in transit
Longer line measures should have...
More line spacing or leading. (Use a longer line height with a wider measure and vice versa. This is because the longer the measure, the harder it will be for the eye to navigate to the start of the next line. Using a longer line height negates this effect.)
IEEE-754
Most common Floating Point encoding atm Split the memory into three sections: Sign, Exponent, Mantissa (also known as fraction or significand)
GNFA Notational Requiremnets
Note that the real difference between GNFA from NFA is that regexes can be used on transition arrows. 1. Start state has no arrows coming in. 2. Start state has arrows going out to every other state. 3. Accepted state has no arrows coming out. 4. Accepted state has arrows coming in from every other state. 5. Except for start and final states, every state has arrows going to every other state and also to itself.
**The promise arguments, resolve, and reject are what type in JS?**
On the backend of the actual ajax call: They're functions that should be called depending on the outcome. Call resolve(return) on success Call reject(error) on failure
A language is regular IFF there is some NFA that recognizes it. Prove this.
One direction of the "if and only if" condition states that a language is regular if some NFA recognizes it. Theorem 1.39 shows that any NFA can be converted into an equivalent DFA. Consequently, if an NFA recognizes some language, so does some DFA, and hence the language is regular. The other direction of the "if and only if" condition states that a language is regular only if some NFA recognizes it. That is, if a language is regular, some NFA must be recognizing it. Obviously, this condition is true because a regular language has a DFA recogniz- ing it and any DFA is also an NFA.
Osteopathic Medicine
Osteopathy is a type of alternative medicine that emphasizes massage and other physical manipulation of muscle tissue and bones.[1] Its name derives from Ancient Greek "bone" (ὀστέον) and "sensitive to" or "responding to" (-πάθεια).[2][3][4] In the United States, osteopathic physicians are trained and are certified to practice medicine. They represent a branch of medicine called Osteopathic Medicine. Osteopaths trained elsewhere are trained only in manual osteopathic treatment, generally to relieve muscular and skeletal conditions, and are referred to as osteopathic practitioners.[5][6][7] They are not allowed to call themselves Osteopaths in the United States to avoid confusion with certified physicians. In the United Kingdom, France, Germany, Australia and New Zealand osteopaths are registered and regulated by law as therapists but may not practice medicine (although Germany, like Canada, allows US-trained osteopathic physicians to practice).
**Why use multiple CDNs?**
Popular CDNs with popular libraries are likely to be cached before visting websites. Browsers have an upper limit (6-ish now, spec says 2) to open parallel connections to one host.
**How do you center an element by using the child absolute method?**
Position the parent element (position meaning display: relative, fixed, absolute, sticky) Display: absolute on to-be centered element Top: 50%, Left: 50%, margin-right: (50% of child width), margin-bottom (50% of child height) Note that you can use this to center either/or horizontal and vertical centering
Matt Cartmill proposed a different idea: the "visual predation hypothesis"
Predators are best served, ostensibly, by having extremely good depth perception. That would help them to better locate and more effectively take down their prey, whether that's a leopard stalking a gazelle or a raptor snatching a rabbit in its talons, or one of our primate ancestors grabbing an insect from the branch of a tree. Cartmill thought his explanation was the most elegant, because it also explained other evolutionary changes that are distinctive to primates. Early primates, for example, hunt by sight rather than by scent. Cartmill thought that the reduction in their ability to smell was a side effect of the eyes' convergence, simply because the space available for the nose and its connections to the brain became smaller as it was crowded out by the eyes.
Priority Queues are...
Priority queues are a kind of queue in which the elements are dequeued in priority order. They are a mutable data abstraction: enqueues and dequeues are destructive. Each element has a priority, an element of a totally ordered set (usually a number) More important things come out first, even if they were added later Our convention: smaller number = higher priority There is no (fast) operation to find out whether an arbitrary element is in the queue Useful for event-based simulators (with priority = simulated time), real-time games, searching, routing, compression via Huffman coding
What is intractibility?
Problems that can be solved in theory (e.g., given large but finite time), but which in practice take too long for their solutions to be useful, are known as intractable problems
Downside of program/process isolation?
Programs can't share data with each other, but this is made possible by using the same mapping to allow programs to share data by pointing to same data (fonts, dialogs, etc)
Explain Promise.prototype.then. Its params and return values.
Promise.prototype.then takes two cb functions. The first is for success, resolve(). The second is for error reject(). The second is optional and can be substituted for .catch. Promise.prototype.then returns another Promise and thus can be chained. This is useful if one async call depends on another async call.
How many calories are in Proteins, Carbs, Fats?
Proteins - 4 cals, Carbs - 4 calos, Fats - 9 cals
Proving iff statements
Prove if-then in both directions.
**How do pseudo elements and pseudo classes differ?**
Pseudo elements create new virtual elements. (::) Pseudo classes - simple selectors in a sequence of selectors that represent non presentational characteristics (:)
The Natural similar to what is said to Elliot Hulse
RSD: It is not what you say, but how you say it. EH: Successful people don't make the right decisions, they make their decisions right.
what react function is called to create an element in react
React.createElement();
Jason Santa Maria about readability
Readability doesn't mean that people will WANT to read your type. Good type should make people want to read it.
What are the primary colours?
Red Yellow Blue
Primary colors?
Red Yellow Blue (Formerly standard set for paints)
What are the three ways to get the transpose of a matrix A?
Reflect across the main diagonal from top-left to bottom-right. Write the rows of A as the columns of A'. Write the columns of A as the rows of A'
What are the Unix File types? (7 excluding Door including two of device files)
Regular: - Directory : d Symbolic link: l Named Pipe: p Socket: s Device file: c(haracter), b(lock)
R
Romeo (ROW-ME-OH)
Sample Content for Developers?
Sample copy spans the entire range of possible lengths, not just what's convenient for the mockup. Required data, particularly such as user photos, are occasionally omitted, and a concrete design is presented for this situation. Undesirable examples of input are considered; for example, extremely portrait or extremely landscape aspect-ratios in images which your design would prefer to be square. Names include 'extreme' or unfamiliar examples, including very long and non-breaking forenames and surnames. A poor design features only Bob Janeson and Jane Bobson. Addresses are not constrained by locale. Almost every possible length, format and arrangement of address can be found somewhere in the world. Allow space and flexibility. Lorem ipsum is not found anywhere in the design.
Combinational vs Sequential logic?
Sequential Logic: Compute their output based on input and state, and that the state is updated based on a clock. Combinational Logic: Combinational logic implement Boolean functions, so they are functions only of their inputs, and are not based on clocks.
Describe Promise.race(); - How is this settled?
The Promise.race(iterable) method returns a promise that resolves or rejects as soon as one of the promises in the iterable resolves or rejects, with the value or reason from that promise.
What is decidability?
The ability to determine whether or not an input can be dealt with - by membership within a set of formulas and returns a bool to demonstrate this. In logic, the term decidable refers to the decision problem, the question of the existence of an effective method for determining membership in a set of formulas, or, more precisely, an algorithm that can and will return a boolean true or false value that is correct (instead of looping indefinitely, crashing, returning "don't know" or returning a wrong answer). Logical systems such as propositional logic are decidable if membership in their set of logically valid formulas (or theorems) can be effectively determined.
Clock rate?
The clock rate typically refers to the frequency at which a chip like a central processing unit (CPU), one core of a multi-core processor, is running and is used as an indicator of the processor's speed. It is measured in clock cycles per second or its equivalent, the SI unit hertz (Hz). The clock rate of the first generation of computers was measured in hertz or kilohertz (kHz), but in the 21st century the speed of modern CPUs is commonly advertised in GigaHertz (GHz). This metric is most useful when comparing processors within the same family, holding constant other features that may impact performance. Video card and CPU manufacturers commonly select their highest performing units from a manufacturing batch and set their maximum clock rate higher, fetching a higher price. The clock rate of a CPU is normally determined by the frequency of an oscillator crystal. Typically a crystal oscillator produces a fixed sine wave—the frequency reference signal. Electronic circuitry translates that into a square wave at the same frequency for digital electronics applications (or, in using a CPU multiplier, some fixed multiple of the crystal reference frequency). The clock distribution network inside the CPU carries that clock signal to all the parts that need it. An A/D Converter has a "clock" pin driven by a similar system to set the sampling rate. With any particular CPU, replacing the crystal with another crystal that oscillates half the frequency ("underclocking") will generally make the CPU run at half the performance and reduce waste heat produced by the CPU. Conversely, some people try to increase performance of a CPU by replacing the oscillator crystal with a higher frequency crystal ("overclocking").[2] However, the amount of overclocking is limited by the time for the CPU to settle after each pulse, and by the extra heat created. After each clock pulse, the signal lines inside the CPU need time to settle to their new state. That is, every signal line must finish transitioning from 0 to 1, or from 1 to 0. If the next clock pulse comes before that, the results will be incorrect. In the process of transitioning, some energy is wasted as heat (mostly inside the driving transistors). When executing complicated instructions that cause many transitions, the higher the clock rate the more heat produced. Transistors may be damaged by excessive heat.
**What is the cost function?**
The cost function can be represented in different ways, sometimes as MSE or whatever, but this is the function that we want to minimize in order to reduce how much we ****ed up.
What is the difference between a recursive (or inductive) definition and a circular definition?
The difference between a circular definition and a recursive definition is that a recursive definition must always have base cases, cases that satisfy the definition without being defined in terms of the definition itself, and all other cases comprising the definition must be "smaller" (closer to those base cases that terminate the recursion) in some sense. In contrast, a circular definition may have no base case, and define the value of a function in terms of that value itself, rather than on other values of the function. Such a situation would lead to an infinite regress.
For typography, in both print and in web why not use the darkest black?
The difference is subtle, but important in my opinion. It makes the text appear slightly softer while still maintaining a good contrast. (High contrast such as black on white can cause eye strain. Also there is evidence that it is particularly bad for people with dyslexia. For further info read articles at UX Movement and The Bristol Dyslexia Centre. WCAG provide details on what is acceptable colour contrast, but dont state an upper limit. Personally, I like to use a different algorithm that provides an upper contrast warning. For further info, see this article at Spider Trax: "Does W3C Get Its Contrasts Wrong?" Slightly off topic, but check out Contrast-A, a good tool made by Das Plankton for picking accessible color schemes.)
What are injective functions?
The function is injective (one-to-one) if every element of the codomain is mapped to by at most one element of the domain. That is EVERY element in the codomain should be mapped to by an input. notationally: ∀x,x'∈X, f(x) = f'(x) => x = x' if x1 != x2 then f(x1) != f(x2) can use horizontal line test
What are surjective functions?
The function is surjective (onto) if every element of the codomain is mapped to by at least one element of the domain. (That is, the image and the codomain of the function are equal.) surjection can be used to describe a surjective function ∀y∈Y,∃x ∈X s.t. y = f(x)
CSS transforms when used in percentages calculate what size?
The size of the bounding box (the box that the elemnt is in)
STAT244: variance vs standard deviation?
The standard deviation is the square root of the variance. The standard deviation is expressed in the same units as the mean is, whereas the variance is expressed in squared units, but for looking at a distribution, you can use either just so long as you are clear about what you are using. For example, a Normal distribution with mean = 10 and sd = 3 is exactly the same thing as a Normal distribution with mean = 10 and variance = 9
Standard Deviation vs Variance? How are the two related? What units do they use?
The standard deviation is the square root of the variance. The standard deviation is expressed in the same units as the mean is, whereas the variance is expressed in squared units, but for looking at a distribution, you can use either just so long as you are clear about what you are using. For example, a Normal distribution with mean = 10 and sd = 3 is exactly the same thing as a Normal distribution with mean = 10 and variance = 9. You don't need both. They each have different purposes. The SD is usually more useful to describe the variability of the data while the variance is usually much more useful mathematically. For example, the sum of uncorrelated distributions (random variables) also has a variance that is the sum of the variances of those distributions. This wouldn't be true of the SD. On the other hand, the SD has the convenience of being expressed in units of the original variable.
What is total coverage in CMYK?
The sum of CMYK percentages. Recommended to avoid exceeding 240%
What is 802.11's medium on layer 1?
The symbol is the radio frequency wave.
STAT244: t-val vs p-val?
The t- value is a test statistic. The p value is a significance level. A test statistic is the result of a statistical test. The exact formula for t depends on what t test you are doing (one sample? two sample? if two sample, paired or independent?) but for two sample tests it is a standardized difference between the two means. (For the formulas see any book or Wikipedia or Mathworld or whereever). That is, it is a measure of how far apart the two means are. A p value answers the following question: If, in the population from which this sample was randomly drawn, the null hypothesis was true, how likely is it that I would get a test statistic at least as extreme as the one I got in a sample of the size I have?
Architecture vs Microarchitecture?
The term architecture is used here to describe the attributes of a system as seen by the programmer, i.e., the conceptual structure and functional behavior, as distinct from the organization of the data flow and controls, the logical design, and the physical implementation.
How does signal edging work?
The transition is what represents the signal. But only one of them - rising or falling represents
Why add vinegar to poached eggs?
The usual problem with eggs is that the whites often end up too firm or tough by the time the yolks are ready. This is because egg whites are mostly protein, and protein starts to set (coagulate) as soon it meets heat. Yolks cook slower to begin with, and even more slowly when they are surrounded by their whites. Adding vinegar to poaching water makes the whites firm even faster to prevent them from dispersing in the water. But that extra firmness comes with a slightly grainy texture and an odd flavor. I want my poached eggs with lovely tender yolks and whites. So I say, hold the vinegar.
What's semantic oriented programming?
The way of how these semantic information are represented in the system vary according to the approach chosen (see below), common to these approaches are the following features: The semantics represent static facts, that is: facts that describe the domain in question at a given moment, and which do not change during runtime (as opposed to Semantic Web for instance) The system has native access to these semantic structures during compile time and runtime, and can interpret them in order to fulfill the requested features Clear separation from logic and implementation (where possible) In many cases, SOP supports the notion of Single Source of Truth (SSoT), such that every semantic concept is stored exactly once, Any possible linkages to this concept are by reference only A programmer can freely and quickly add new semantic meanings without breaking compatibility with the system environment Goals: Improving the maintainability of a software Improving the transparency of a software Flexibility by allowing exchangeability of logic or implementation Optimal support for agile development processes (refactoring)
X-Ray Vision Hypothesis
Theoretical neurobiologist Mark Changizi has yet another idea. In 2008 in the Journal of Theoretical Biology, he offered up the "X-ray vision hypothesis". In short, forward-facing eyes allowed our ancestors to see through the dense leaves and branches in their forest habitat. The catchy name for his hypothesis comes from a curious phenomenon. "When you hold up your finger vertically and fixate your eyes on something far beyond it," he writes, "you perceive two copies of your finger, and both copies of your finger appear transparent." Thus, you have the ability to "see through" your finger, as though you were seeing with X-ray vision.
What problem(s) did Unicode give to ASCII?
There are wasteful bits - 24-25 (so 4x the size) of them depending which ASCII standard is being used. Also, some computers will interpret 8 '0's in binary as a NULL character meaning it will stop communication.
Briefly describe LU decomposition
This is the method by which you can solve a system of linear equations by factoring a complex matrix into more manageable lower and upper triangular matrices.
How to get black in CMYK?
There's a ton of different ways. The basic concept is that in print design, there are different types of black. Some people will go 100% key and CMY set to 0% Others will use 100% CMY and 0% key. Other combinations are a mix of CMYK together. http://graphicdesign.stackexchange.com/questions/5611/what-cmyk-values-should-i-use-for-rich-black-and-how-should-i-handle-tints-shad
UTF-7?
There's something called UTF-7, which is a lot like UTF-8 but guarantees that the high bit will always be zero, so that if you have to pass Unicode through some kind of draconian police-state email system that thinks 7 bits are quite enough, thank you it can still squeeze through unscathed.
Does a correlation of 0 imply zero relationship between two variables?
Therefore, a correlation of 0 does not mean zero relationship between two variables; rather, it means zero linear relationship. (It is possible for two variables to have zero linear relationship and a strong curvilinear relationship at the same time.)
ELM: FEM - 3 Types of collections, their length and types?
They're all flat immutable data structures * Records (Fixed length, mixed contents) * Tuples (Fixed length, mixed contents) * Lists (Variable length, uniform contents)
What is the purpose of the 6to4 mechanism?
This is intended to help migrate IPv4 to IPv6. CAn be used to drive IPv6 packets into an IPv4 network. IMPORTANT: 6to4 may be used by an individual host, or by a local IPv6 network. When used by a host, it must have a global IPv4 address connected, and the host is responsible for encapsulation of outgoing IPv6 packets and decapsulation of incoming 6to4 packets. So basically packs IPv6 packets into IPv4 and vice versa in a sense.
The Promise constructor takes one argument. Explain this.
This is the executor function. The executor function is a callback passed into the Promise constructor. It is executed right away and is passed a resolve and reject function. Depending on logic of success or error one should call these functions appropriately.
position: relative
This keyword lays out all elements as though the element were not positioned, and then adjust the element's position, without changing layout (and thus leaving a gap for the element where it would have been had it not been positioned). The effect of position:relative on table-*-group, table-row, table-column, table-cell, and table-caption elements is undefined.
**When finding the sum of squared error - why do we divide by 1/m?**
This removes dependency on data set size and is essentially the mean sq error. (MSE)as opposed to the RSS
What is the minimum # of distinct mac address fields in 802.11? Why?
Three. You need to go through an AP to get to the receiver. SRC->AP->DST
Describe the tiers of Autonomous systems
Tier 3 - large companies/organizations, small-medium ISPs Tier 2 - moderately large telecommunications companies Tier 1 - only 15 of em - arge ass telecom systems (largest of the three)
What is the traddeoff in dynamic programming?
Time and memory. D.P. uses additional memory to save computation time.
David Deida - Way of the Superior Man (Chapter 1 23:12) - What does Deida propose as a way to get in touch with deepest purpose?
To stop doing. Start feeling. Feel the source of every thought coming and going as a man during meditation. Be in isolation.
How to implement tracking in CSS?
Tracking is the space between characters in text. I'll admit, this one's a bit of a grey area when it comes to "Practical Typography," in that CSS doesn't give us huge control over it. Usually, you won't have to worry about it for small text, it's only for titles that it becomes an issue. Generally speaking, adding letter-spacing: 1px; or letter-spacing: 2px; to your CSS should be enough space between the letters. Another place it would be beneficial to add tracking to is small-caps. Here it's generally considered good practice to add an extra pixel or two between the characters, as they naturally appear larger.
What class of exceptions are system calls?
Traps.
What is fc00::/7
ULA - unique local address. Approximate IPv6 counterpart of IPv4 private addresses. These addresses are reserved for local use in home and enterprise environments and are not in public address space. These addresses might not be unique, and there is no formal address registration. Packets with these addresses in the source or destination fields are not intended to be routed on the public Internet but are intended to be routed within the enterprise or organisation.
What's bigger, category-wise?
URI is bigger, URL is spec or location of resource and must include scheme
What is Unicode?
Unicode isn't an encoding, although unfortunately, a lot of documentation imprecisely uses it to refer to whichever Unicode encoding that particular system uses by default. On Windows and Java, this often means UTF-16; in many other places, it means UTF-8. Properly, Unicode refers to the abstract character set itself, not to any particular encoding. The difference here is that Unicode uses regular numbers (typically represented by Hexadecimal notation) to encode characters. But luckily, Unicode and ASCII (which uses bits) line up! See U+0041 is used to represent the letter A but is also 65 in decimal!
What are the operators on regular languages? What is the order of operations (precedence) for them?
Union:A∪B={x|x∈Aorx∈B}. Concatenation:A◦B={xy|x∈Aandy∈B}. Star:A∗ ={x1x2...xk|k≥0andeachxi ∈A}. Precedence: Star, concat, union
Are uppercase characters first or lowercase characters first in ASCII?
Uppercase from 65 to 90. Lowercase from 97 to 122
How to determine font sizes for hierarchy?
Use a modular scale! (www.modularscale.com)
**How do we constrain values of output to between 0 and 1?**
Use a sigmoid/logistic function wrapper
Write back policy?
Write-back (also called write-behind): initially, writing is done only to the cache. The write to the backing store is postponed until the cache blocks containing the data are about to be modified/replaced by new content.
How to implement leading in CSS?
Using the CSS line-height property, you can easily assign space between your lines of copy. Generally speaking, for large blocks of text, 1.5 times the size of the text is a good size. Smaller text should have tighter leading, and huge text should have a lot. It's not that complicated, really.
By convention, the start variable is...
Usually occurs on left hand side of topmost rule.
Given the following grammar, describe it: A → 0A1 A→B B→#
V = {A,B} ∑ = {0,#,1} R = the set of rules given S = A
UTF-8?
Variable length encoding, 1-4 bytes per code point. ASCII values are encoded as ASCII using 1 byte. How is this variable length? The first bits of the bytes indicate how many bytes to use!e.g. 110xxxxx (start new character being two bytes) 10xxxxxx (continuation) Then combine these to interpret the character. 1110xxxx + 10xxxxxx + 10xxxxxx (this is still a problem for some computers that will just interpret these as separate characters) UTF-8 was another system for storing your string of Unicode code points, those magic U+ numbers, in memory using 8 bit bytes. In UTF-8, every code point from 0-127 is stored in a single byte. Only code points 128 and above are stored using 2, 3, in fact, up to 6 bytes. This has the neat side effect that English text looks exactly the same in UTF-8 as it did in ASCII, so Americans don't even notice anything wrong. Only the rest of the world has to jump through hoops. Specifically, Hello, which was U+0048 U+0065 U+006C U+006C U+006F, will be stored as 48 65 6C 6C 6F, which, behold! is the same as it was stored in ASCII, and ANSI, and every OEM character set on the planet. Now, if you are so bold as to use accented letters or Greek letters or Klingon letters, you'll have to use several bytes to store a single code point, but the Americans will never notice. (UTF-8 also has the nice property that ignorant old string-processing code that wants to use a single 0 byte as the null-terminator will not truncate strings).
Vinegar and boiling water?
Vinegar raises the boiling point of water.
Why do we need virtual memory?
Virtual memory is a layer of indirection. - "Any problem in CS can be solved w indirection" Problem #1 - Not enough memory. Sol. use swaps from Hard disk - take old memory from ram and move into hard disk, and update new processes into ram Problem #2 - Holes in address space of RAM sol. use separate mappings for each program and in different parts of RAM Problem #3 - Keeping programs secure sol. keep separate mappings for each process and thus though the instructions say to access the same memory location, each process is isolated!
**How can HTTP be a stateless protocol if connections are persistent by default?**
When "stateless" is said, think immutable, mutable states. Stateless HTTP is possible with persistent connectiosn because each connection is still independent of each other. There's no mutable state that affects separate connections.
When would we need 4 MAC addresses in 802.11?
When APs need to communicate wirelessly.
David Deida - Way of the Superior Man (Chapter 1 18:31) - Deida says we have very little practices for what in modern society?
We have very little practices for men to feel into their deepest purposes. Therefore most men begin to function from superficial desires. Instead we should source desires from divinity.
What are web safe fonts?
Web-safe fonts are fonts likely to be present on a wide range of computer systems, and used by Web content authors to increase the likelihood that content displays in their chosen font. If a visitor to a Web site does not have the specified font, their browser tries to select a similar alternative, based on the author-specified fallback fonts and generic families or it uses font substitution defined in the visitor's operating system.
What does it mean for an operation to be closed over a set?
What does it mean for an operation to be closed? if ~ is op. A, B, sets. a~b results in x that exists in A U B. used to describe the operation in relation to a set. if op is closed, a set satisfies the closure property if op is closed on set
Singlecycle architecture vs multicycle architecture?
What does steady state mean here...?
https://heartiste.wordpress.com/2014/06/18/value-shit-tests-vs-comfort-shit-tests/
When a woman is seeking sexiness, her unrehearsed interrogation will take the form of value filters. The value shit test is a test for male aloofness, state control, abundance, coolness, and social acumen. When a woman is seeking security, she'll prod for signals of attainability and seriousness. The comfort shit test is lethal to newbies because they don't recognize it before it's too late, and because this shit test can sound *exactly* like a value shit test. But the context in which it is delivered is everything. What works to neutralize value shit tests won't for comfort shit tests. For this reason, Agree and Amplify is not a good response to the latter. All that will accomplish is boxing yourself into the "entertainment monkey" cad caricature she can have fun with and then safely and without regret disengage from once the act bores her. The best Comfort Shit Test response alleviates a girl's insecurity while strengthening emotional closeness.
**Why do we need to serialize and deserialize JSON?**
When transmitting data or storing them in a file, the data are required to be byte strings, but complex objects are seldom in this format. Serialization can convert these complex objects into byte strings for such use. After the byte strings are transmitted, the receiver will have to recover the original object from the byte string. This is known as deserialization.
**Difference between attribute and property?**
When writing HTML source code we create attributes in our code i.e. class, id, etc When the DOM parses the source code it creates a bunch of DOM nodes, these DOM nodes are objects that have PROPERTIES as appropriately called because they are objects. One of these properties is the 'attribute' property, which is why some attributes and properties are self-reflected
STAT 244: in R what does this return? a <- c(1,2,3) a+1
[1]2,3,4
**Describe the .on function from Jquery 3**
`.on( events [, selector ] [, data ], handler )` event - event that triggers selector - filter data - json obj to pass to event handler handler - function to execute
How can SASS string interpolation help with file paths?
``` $root: "/images/"; #form { background-url:("#{$root}background.jpg"); } $name: "my-class"; .#{$name}{ color: Blue; } ```
Explain the cascade problem and its solution
``` #form input[type=textbox], #form text-area{ ... } ``` deeply nested rules - with multiple descendant selectors ability to nest rules to reflect this hierarchy with SASS In SASS you have the... ability to nest properties font to describe font-family, font-size, etc.etc ability to nest hierarchically. parent selectors help be more semantic about this
How can you use SASS functions to semantically code column widths
``` $app-width: 900px; @function column-width($cols){ @return ($app-width / $cols) - ($cols * 5px); } .col2 { width: column-width(2); } ```
What is the shape property in binary heaps?
a binary heap is a complete binary tree; that is, all levels of the tree, except possibly the last one (deepest) are fully filled, and if the last level is not complete then nodes are filled left to right.
React component names must start with
a capital letter
What is a function?
a function is simply a relation between a set of inputs and a set of outputs A function relates each element of a set with exactly one element of another set (possibly the same set). A function f from X to Y is a subset of the Cartesian product X × Y subject to the following condition: every element of X is the first component of one and only one ordered pair in the subset.[4] In other words, for every x in X there is exactly one element y such that the ordered pair (x, y) is contained in the subset defining the function f. This formal definition is a precise rendition of the idea that to each x is associated an element y of Y, namely the uniquely specified element y with the property just mentioned.
__dirname in node is...
a global variable that is actually local to each module has directory name of the current module
Describe what a "thunk" is in Functional programming
a thunk is a subroutine created to assist a call to another subroutine. Thunks are primarily used to represent an additional calculation that a subroutine needs to execute, or to call a routine that does not support the usual calling mechanism Kyle Simpson: "A thunk is a function that has everything already to give you some value back -- doesnt need any arguments, you simply call it." ``` function add(x,y){ return x + y; } var thunk = function(){ return add(10,15); } thunk() //25 ``` "this has now become a container of state at that time" -- underpinning behind promises. https://github.com/stephenhuh/snippets/blob/master/thunks.js Ravi Chugh: "We have "delayed" the evaluation of the expression by wrapping it in a function that takes the dummy argument (). Functions like are called "thunks" and turn out to be extremely useful for programming in (and compiling) functional languages. We will put thunks to good use later in the course."
STAT244: vectors in R are ___ type
all the same type
**What does the sigmoid function graph look like?**
asymptotic at 1 and -1, intercept at 0.5 1/1+e^-z
Is an I/O Interrupt synchronous or async?
async -- external to the processor.
Beta male behavior is rewarded...
at mediocrity at best.
Regression Analysis: P-Value
he p-value is defined informally as the probability of obtaining a result equal to or "more extreme" than what was actually observed, when the null hypothesis is true.[5][6][7] This ignores the distinction between two-tailed and one-tailed tests which is discussed below. In frequentist inference, the p-value is widely used in statistical hypothesis testing, specifically in null hypothesis significance testing. In this method, as part of experimental design, before performing the experiment, one first chooses a model (the null hypothesis) and a threshold value for p, called the significance level of the test, traditionally 5% or 1% [8] and denoted as α. If the p-value is less than or equal to the chosen significance level (α), the test suggests that the observed data is inconsistent with the null hypothesis, so the null hypothesis must be rejected. However, that does not prove that the tested hypothesis is true. When the p-value is calculated correctly, this test guarantees that the Type I error rate is at most α. For typical analysis, using the standard α = 0.05 cutoff, the null hypothesis is rejected when p < .05 and not rejected when p > .05. The p-value does not, in itself, support reasoning about the probabilities of hypotheses but is only a tool for deciding whether to reject the null hypothesis.
span[lang] {font-weight:bold;} What selectors are being used here?
span[lang] uses the attribute selector to find a span with the lang attribute to make bold.
How to search for numbers within a string?
string.match(/\d+/g);
What is a radix?
the base of a system of numeration
Image vs Range?
the image is synonymous with the range but mathematicians prefer to use the term image because range can be ambiguous The image (sometimes called the range) of f is the set of all values assumed by f for all possible x; this is the set {f(x) | x ∈ X}. The image of f can be the same set as the codomain or it can be a proper subset of it. It is, in general, smaller than the codomain; it is the whole codomain if and only if f is a surjective function.
What is the heap property?
the min-heap property: the value of each node is greater than or equal to the value of its parent, with the minimum-value element at the root. the max-heap property: the value of each node is less than or equal to the value of its parent, with the maximum-value element at the root.
Explain ReactDom.Render()
three args: 1. element 2. container 3. callback returns a reference to the component. Render a React element into the DOM in the supplied container and return a reference to the component (or returns null for stateless components). If the React element was previously rendered into container, this will perform an update on it and only mutate the DOM as necessary to reflect the latest React element. If the optional callback is provided, it will be executed after the component is rendered or updated.
What styles are affected to node5? <style> ol li { color: blue; } ol, li { font-weight: bold; } ol > li { font-size: 30px; } ol ~ li { color: yellow; } ol + li { color: green } </style> <html> <ol> <ol> <li>node 1</li> <ul> <li>node 2</li> </ul> <li>node 3</li> <li>node 4</li> </ol> </ol> <li>node 5</li> <li>node 6</li> <li>node 7</li> <ul> <li>node 8</li> </ul> </html>
yellow, replaced by green, bold
Can we find the optimal DFA?
yes! using minimization algorithm, 2 be explored later on with hopcrofts algorithm using partitions and equivalence classes