Computer Science Supplemental Topics #1-#32
(9) When an airplane lands at an airport, the following events must occur before the plane can take off again. - The arriving passengers exit the plane - The departing passengers board the plane - The arriving luggage is removed - The departing luggage is loaded into the hull - The plane is refueled - The cabin is resupplied with drinks and snacks Identify the parts of the above scenario that must be implemented sequentially.
- The arriving passengers must exit the plane - The arriving luggage must be removed all before - the departing passengers board the plane (next flight) - the departing luggage is loaded into the hull
(11) Logic Diagram
- consists of gates and symbols that can directly replace an expression in Boolean arithmetic - can perform the AND, NAND, NOR, NOT, OR, XNOR, and XOR operations
(9) When an airplane lands at an airport, the following events must occur before the plane can take off again. - The arriving passengers exit the plane - The departing passengers board the plane - The arriving luggage is removed - The departing luggage is loaded into the hull - The plane is refueled - The cabin is resupplied with drinks and snacks Identify the parts of the above scenario that could be implemented concurrently.
- the plane can be refueled - The cabin can be resupplied with drinks and snacks - the passengers can board/exit the plane - the arriving/departing luggage can be removed/loaded
(5) Identify 1 advantage and 1 disadvantage of virtual memory
-An advantage is ability to share memory used by libraries between processes -A disadvantage is increased hardware costs.
(2) Identify 1 advantage and disadvantage of using a computer to solve complex problems
-An advantage of using a computer is that you can avoid human mistakes. -A disadvantage is that you limit learning because of too much dependence on computers.
(2) State the key differences between hardware, software, and firmware.
-Hardware includes the physical parts of the computer. -Software is the set of instructions that help a computer perform tasks. -Firmware is a software that controls the hardware and helps devices communicate.
(5) Identify 1 example of volatile memory and 1 example of non-volatile memory
-RAM is an example of volatile memory -ROM is an example of non-volatile memory
(6) Describe the reasons for solid-state disk drives having lower latency than hard disk drives
-Solid - state disk drives are faster when starting up and transferring data - they are smaller and use less power
(3) Explain the differences between a thin and fat client:
-Thin Clients run on resources on a central server and has less security threats -Thick clients run on locally installed resources and have more security threats
(3) Suggest 2 reasons why the Berkeley SETI Research Center may have chosen to use a distributed computing model for its SETI@home project.
1)To split up work because the systems are more efficient that way 2)Info isn't stored in a central location so there would be less wait times
(5) Random access memory
A computer's short term memory - handles apps
(2) Peripheral Device
A connected device that allows a computer to have more functions
(2) Computer
A device that stores and processes data; it also performs operations by itself
(6) Hard Disk Drive
A kind of technology that stores the operating system, applications, data files, pictures, and music that your computer uses
(4) Program counter
A register in the processor which has the address of the next instruction to be executed from memory.
(1) Pattern
A reusable solution to a common problem in computer science
(5) Non-volatile memory
A type of computer memory that can retain stored information even after power is removed
(2) Firmware
A type of software that controls the hardware and helps devices communicate
(4) Arithmetic Logic Unit
A unit in a computer that enables it to carry out arithmetic and logical operations.
(1) Write a regular expression that works for ABA, ACA, and ADA
ABA|ACA|ADA or A[BCD]A
(4) Identify the functions of the Arithmetic Logic Unit (ALU) and the Control Unit (CU).
ALU performs arithmetic and logical operations and CU directs the operation of the processor.
(3) Compare a centrally controlled system with a distributed system.
All calculations are done on one system as opposed to being distributed to multiple systems
(2) Hardware
All parts that you can touch when using a computer
(8) Identify at least 2 system resources in desktop and/or laptop computers and discuss the importance of properly managing these resources
CPU, hard drive, memory - to optimize the capacity of these network resources
(8) Evaluate various connectivity options for cell phones(e.g, wireless, cellular, etc.) in terms of speed, bandwidth, reliability, and accessibility
Cellular devices will experience faster data, download, and upload speeds. - Can be used for phone calls, streaming videos, Wi-Fi, and browsing the internet.
(1) Regular Expression
Characters that define a search pattern
(5) Volatile memory
Computer storage that only maintains its data while the device powered
(3) Thin Client
Computer that runs on resources stored on a central server
(9) Describe 1 problem that can arise from multithreading.
Difficulty of debugging: It is harder to identify root causes when errors occur
(1) Boolean "or"
Has two options that are true or false
(2) Describe the composition of a computer network, including at least 3 examples of necessary hardware
It's made up of hardware and software; routers, cable, and modem
(6) Explain the need for persistent storage
It's needed to store data in a non-volatile device during and after the running of the program -prevents data loss
(1) Concatenation (+)
Joining two strings together
(6) Outline the issues related to both the increasing amount of data and the need to retain it
Large amounts of data are hard to process and store; there are many challenges regarding storing and accessing data in a time efficient/cost efficient manner
(2) Network
Multiple computers that are connected to exchange files or communicate
(3) Fat Client
Networked computer system with locally installed resources
(6) Secondary Storage
Non-volatile storage device used to store data on a long term basis
(1) Describe the meaning of a plus sign (+) in a regular expression.
One or more
(4) Control unit
Part of the CPU which directs the operation of the processor.
(3) Parallel Computing
Process of dividing large problems into smaller ones which can be solved at the same time
(9) Atomic Operation
Program operations that run completely independently of any other processes.
(10) NOT
Returns the opposite of the original value
(2) Software
Set of instructions that allows a computer to perform tasks
(3) Explain why an airline would choose to use a centralized computing model for its ticket reservation system rather than a decentralized computing model.
So that all tickets that are related to that specific airline are in one area and don't collide with other times and flights
(1) Quantifier
Specifies the number of occurrences of a character
(1) Empty string
String that has zero characters
(3) Distributed System
System that has multiple parts that are spread across multiple computing devices on a network
(6) Primary Storage
The computer's main memory that includes RAM, ROM, cache memory, and flash memory
(5) Describe main memory.
The main workplace where programs and data are kept when the processor is actively using them.
(3) Concurrent Computing
When multiple computations are running at the same time instead of one after another
(5) Main memory
Where programs and data are kept when the processor is using them (RAM)
(7) Store
With computers, you store information on a storage device, such as an internal hard drive
(1) State 3 different strings that can match the following regular expression: X+Y*Z
XXYZ XXZ XXXYYYZ
(1) Describe the meaning of an asterisk (*) in a regular expression.
Zero or more
(6) Data Backup
a copy or archive of the important information stored on your devices, stored in a cloud
(5) Cache memory
a fast memory type that holds frequently used instructions and data for quick processing by the CPU
(5) Virtual memory
a feature that enables a computer to compensate shortages of physical memory by transferring pages of data
(4) Memory bus
a set of wires which allows transfers of data and addresses from the main memory to CPU.
(9) Deadlock
a situation in which two computer programs sharing the same resource are effectively preventing each other from accessing the resource
(3) Centralized system
a system where computing is done at a central location using a central computer
(9) Semaphore
a variable or abstract data type used to control access to a common resource
(9) Multithreading
allows multiple commands, or threads to run simultaneously
(7) Address Bus
allows the CPU to send the address to RAM
(7) Data Bus
carries the data between the processor and other components.
(4) Outline the architecture of the central processing unit (CPU)
contains memory holding data and instructions, ALU, control unit, input, output, register
(4) Explain the purpose of the program counter (PC).
contains the address of the next instruction to be executed from memory.
(8) Bandwidth
data transfer capacity of a computer network in bits per second
(6) Solid-State disk drive
electronic storage used to store non-volatile data of dynamic RAM
(6) Identify the consequences of data loss
exposes a business to all sorts of legal actions, fines, and lawsuits
(7) Explain the machine instruction cycle.
fetch, decode, execute, store
(10) Construct a truth table for the following Boolean expression.
https://docs.google.com/document/d/1GZoTEY7IVA-eglmoRzrTZlpA4nCVpCvSRL-HBeaM1ZY/edit (link to truth table)
(10) Construct truth tables using the following operators. You may assume that 0 represents false and 1 represents true.
https://docs.google.com/document/d/1GZoTEY7IVA-eglmoRzrTZlpA4nCVpCvSRL-HBeaM1ZY/edit (link to truth table)
(7) Explain why the program counter (PC) is usually incremented once per instruction cycle.
in order to point to the next instruction in memory
(4) Register
internal memory or immediate access memory stores
(5) Explain the use of cache memory
it acts as a buffer between RAM and CPU holding frequently used data
(9) Explain why a multithreaded solution can be faster to execute than a sequential solution.
it allows for multiple instructions to be processed simultaneously
(8) If a computer is unable to render 3D graphics effectively, identify at least 1 system resources that might be modified in order to achieve better graphics performance
memory, CPU
(2) List 3 examples of peripheral devices in a computer system
mouse, keyboard, microphone
(8) Processor speed
number of cycles per second at which the CPU operates and is able to process info
(8) Connectivity
process of connecting various parts of a network to another
(4) Describe the role of registers in the Central Processing Unit (CPU).
provide storage for the CPU to store info, data, or addresses that are needed in processing
(8) Screen Resolution
resolution is the number of pixels (individual points of color) contained on a display monitor
(10) NAND
returns false if both values are false
(10) NOR
returns true if all values are false
(10) OR
returns true if only one value is true
(10) AND
returns true when both values are true
(10) XOR
returns true when only one or the other value is true
(8) Describe the consequences of installing too little primary data
the CPU cannot properly execute all of its functions or instructions
(7) Outline how the address bus and data bus are used in relation to the fetch and store stages of the machine instruction cycle.
the address bus figures out location of where to fetch from/store and the data bus actually transfers the data to these addresses
(8) Storage capacity
the amount of data a storage device can hold
(7) Decode
the conversion of an encoded format back into the original sequence of characters
(4) Central processing unit
the part of a computer in which operations are controlled and executed
(9) Sequential Processing
the processing that occurs in the order that it is received
(7) Identify which components of the central processing unit (CPU) are involved during the execute stage of the machine instruction cycle
the program counter, ALU, and control unit
(7) Fetch
the retrieval of data by a software program, script, or hardware device
(9) Thread
the smallest sequence of programmed instructions that can be managed independently by a scheduler
(8) Ergonomics
the study of how we interact with our computers
(6) Latency
the time it takes for data to be transferred between its original source and its destination (in milliseconds)
(7) Execute
to run the program in the computer; in usage, people run programs and systems execute them
(10) Evaluate the following expression when a = true, b = false, and c = false. (a NAND b) OR c
true