lecture 1-10, 13

Computer hardware

- "Those parts of the system that you can hit with a hammer (not advised) are called hardware" - Key design principle of modularity (change one component only without changing whole system) - There are different form factors of system units (all in one vs towers)

The telephone

- 1876: first successful bi-directional transmission of clear speech by Alexander Bell and Thomas Watson - 1940: first successful transmission of digital data through over telegraph wires by George Stibitz

Evolution of the Web

- 1994: Netscape Communications and Yahoo! founded - 1995: first version of Microsoft Internet Explorer released - 1998: Google founded - 1997-2001: "Dot-com" boom and bust - 2004: shift to 'Web 2.0' (eg. wikis)

Microblogging

- A form of broadcast communication that is similar to blogging - The key difference is that smaller portions of content are shared on microblogs - Well-known microblogging platforms include: Twitter Tumblr Pinterest Instagram

Word processors- styles, headers + footers, Footnotes + endnotes

- A named group of formatting changes that can be applied to text in the document - Advantages: ○ Gives the document a consistent appearance ○ Makes applying formatting faster: ○ Select the content and apply the style. ○ Modified the style and all content using the style have their formatting updated automatically. - Header: content found in the top margin of every page - Footer: content found in the bottom margin of every page - Footnote: ○ small note located at the bottom of a page. ○ Provides more information about something in the main text - Endnote: text that appears at the end of the document

Write-N-Cite

- A plugin for Microsoft Word that enables the user to insert references when working in their document - Refworks can be accessed by clicking on the 'ProQuest' or 'Refworks' tab - Using Refworks, you can insert citations and bibliographies

Wikis

- A set of public webpages that can be edited by anyone, which encourages collaboration ○ Can also have private wikis that can only be edited by authorised people - Wiki pages are written in plain text, with wiki markup used to add formatting (italicise text, add links etc.)

Search engines and how they work?

- A website that helps a user to search for information on the WWW - Software indexes content on the web. This index is used to build a list of results based on the search terms entered by the users - Indexing: organising data so that it is easier to search how do they work? - Spiders crawl across the WWW to scan webpages ○ Spiders are programs that follow links and gather information from webpages - The search engine's index is updated with information gathered by the spiders - User enters a search term - The search engine uses algorithms to find the most relevant results in its index ○ They use a number of criteria, such as keywords and popularity, to determine a page's relevance to the user - Search engine gives the user a list of results ○ This list is complied from billions of webpages in a couple of seconds!

ASCII (HINT)

- ASCII = American Standard Code for Information Interchange - Associates English characters with numbers meaning text in documents can be stored as strings of binary - Each ASCII code is 7 bits long, meaning ASCII can represent 128 characters - There are other encoding schemes such as UTF-8 and Unicode

Expansion cards

- Additional circuit board that provides extra functionality - e.g. sound card, graphics card, network card - Plugged into motherboard using slots that follow certain standards: ○ PCI-E, ISA, AGP - Graphics card: ○ Used to perform graphics processing and run the computer's monitors ○ Consist of: >> GPU (either part of CPU or separate graphics card) >>Video memory >>Heatsink and fan >>Ports

advantages and disadvantages of online anonymity

- Advantages: ○ Encourages free expression online, especially around sensitive or personal issues ○ Supports other rights such as the right to privacy - Disadvantages: ○ Use of anonymity to harass and offend other people ○ Difficult to authenticate whether a message (e.g. email) is from the purported sender ○ Makes it difficult for authorities to track criminal activity online

What is software? and kinds of software?

- Aka 'programs' or 'apps'. Instructions and other data used by the computer - User can perform tasks and interact with the hardware through software - Loaded from secondary memory into primary memory, where it is executed by the CPU Kinds of software ○ System software: >>Operating system (eg. Windows, Mac OS X) >> Device drivers >> Diagnostic and maintenance tools (eg. Disk Cleanup) ○ Application software: >> Used by users to perform tasks on the computer

File formats

- All data on a computer is stored in binary - However, a program encodes files in its own way; this is the file format - A program will be unable to open a file if it does not understand the file format

Connectors and buses

- All peripherals are connected to the motherboard via ports - Ports form part of a bus (software and cable) - Wired connections: ○ Universal (universal serial bus) ○ Thunderbolt connector ○ Ethernet ○ VGA, DVI and HDMI for monitors - Wireless connections ○ Wifi, bluetooth

Occupational Overuse Syndrome

- Also referred to as Repetitive Strain Injury (RSI). - Umbrella term for range of conditions characterized by: ○ Muscle discomfort ○ Aches and pains ○ Muscle tightness and spasms ○ Numbness and tingling - Pain may eventually become constant and associated with loss of muscle strength and sleep disturbances. - Factors that can lead to OOS developing include: ○ Repetitive movement - e.g. typing ○ Awkward postures - e.g. sitting at a desk ○ Poor ergonomics ○ Psychosocial factors - excessive workload, impending deadlines ○ Poor work practices - e.g. poor time management - There are a number of steps that can be taken to prevent OOS. - From a workplace perspective: ○ Design equipment and tasks with people in mind e.g. ergonomic workstations. ○ Pay attention to work environment - e.g. lighting. ○ Train and educate all staff. - From a personal perspective: ○ Stop activity when discomfort is felt ○ Maintain correct posture ○ Take regular breaks ○ Avoid prolonged, repetitive movement or activity ○ Manage stress levels ○ Educate yourself about OOS prevention

Connecting to the Internet- ISP vs at home

- An Internet Service Provider (ISP) provides you with an IP address and a connection to the Internet - At home, you plug your modem into your phone jack - Your modem sends and receives information from the Internet over your phone line

Text editors

- Application software that enables the user to edit text - Text is stored using ASCII or another encoding scheme - Used to edit: ○ Text files (.txt) ○ Configuration files ○ Source code - Examples: ○ Notepad ○ Notepad++ ○ TextPad

Word processors

- Application software that enables the user to edit text and add formatting to the text - Files created by word processors store text and formatting information according to a format ○ Proprietary standards, eg. Word file format (.doc) ○ Open standards, eg. ○ OpenDocument format (.odt) >>Microsoft products now use the Office Open XML format e.g. microsoft word, apple pages

Number systems

- Base ○ Specifies the number of digits used by the system ○ Binary is base 2 (has 0 or 1) ○ Decimal is base 10 - Positional notation ○ Describes how numbers are written

Can we trust search engines?

- Bias in the results? ○ Effect of filtering on search results (eg. DMCA, images of child abuse) - Advertising plays a big role in how search engines operate ○ Search engines make money from advertising ○ Companies misuse search engines to get a competitive edge: NakedBus using 'inter city' on Google Adwords - The right to be forgotten (R2BF) ○ In 2014, European Court of Justice decided R2BF meant Google has to remove out-of-date search results when requested by individuals ○ In Europe, the General Data Protection Regulation 2016 contains a more limited 'right to erasure' - R2BF helps an individual to preserve their privacy - However, the R2BF distorts search results and could be abused (eg. a businessman wanting news articles removed from search results)

Summary of bitmap and vector

- Bitmap Images • Pixel width x pixel height = resolution • Use numbers to encode colour of each pixel (more colours = more bits per pixel) • Look jagged when enlarged too much • Take a lot of memory but can be compressed (e.g. JPG) - Vector Images • Defined by mathematical formulae • Can be enlarged and still look nice • Small compared to bitmap images

Problems with webpages

- Broken links ○ Usually the result of a webpage being moved or deleted - No inherent security/tracking/accounting system ○ Difficult to have layers of security and a consistent level of security ○ Websites rely heavily on ad revenues - No inherent way of indexing information ○ Difficult to find information on the web, although search engines help ○ Dynamically generated webpages and different file formats (eg. PDF, archives) also make indexing difficult

Colour Bitmaps

- Colours • Use more than 1 bit per pixel • Map the binary number to a colour

WWII and the Cold War

- Computer technology played an important role in code-breaking during WW2 - Cold War between US and USSR led to a technology and arms race - Peaked with the launch of Sputnik in 1957 - 1958: Advanced Research Projects Agency (ARPA) established - April 1969: construction of ARPANET begins, a packet-switching network

Networking hardware

- Connection ○ Wired, eg. Ethernet ○ Wireless, eg. Wi-Fi, cellular - Network card ○ Can be built into the motherboard or an expansion card ○ Some network cards support wired and wireless connections - Switch ○ Used to connect multiple devices to the same network - Router ○ Directs traffic around the network and connects networks together - Modem (modulator/demodulator) ○ Responsible for transmitting and receiving data on the physical medium ○ Modulates data from computer/router onto a phone line ○ Demodulates signals from a phone line and sends to the computer/router ○ There are different kinds of modems >> Dial-up modems up to 56Kbs >>Broadband (DSL - digital subscriber line) modems between 256Kbs to 20Mbs

Power Supply Unit

- Converts AC voltage to DC voltage for use within the computer

Packet-switching network

- Data is broken into packets, which are then sent on the best route in the network - Each node on the route sends the packet onto its next destination, avoiding congested or broken nodes

Black and White pictures

- Digital Pictures consist of small dots • Each dot is called a picture element (pixel) - Storing information • Black and White are only two states • Use bits to represent pixels (0 = OFF (or black), 1 = ON (or white)) • One to one mapping, so known as Bitmap

Distraction

- Digital devices are highly pervasive and are demanding of our attention. ○ "cognitively penetrating" - Checking - repeatedly accessing your digital device interrupting your current activity. - A 2012 study of 777 students at 6 U.S.universities found that : ○On average a student used a digital device for nonclasspurposes 11 times during a typical school day. ○ 80% indicated that such behaviour caused them to pay less attention in class and miss instruction.

Converting from decimal to binary

- Divide the decimal by base (for binary it is 2) ○ 35/2=17 remainder 1, ○ 17/2=8 remainder 1, ○ 8/2=4 remainder 0, ○ 4/2=2 2 reminder 0 ○ 2/2=1 remainder 0 ○ 1/2=0 remainder 1 Then count remainders bottom up

Online anonymity- Do Not Track initiative,

- Do Not Track initiative: ○ A browser option that tells an advertiser you do not want them to track your browsing habits ○ Voluntary system; the advertiser is under no obligation to abide by Do Not Track requests

IP addresses and domain names

- Domain name system (DNS) is used to convert between IP addresses and human-readable text (domain name) - DNS servers perform the translation between IP address and URL

Bits and Bytes

- Each binary number is known as a Binary digIT, or bit. - A bit can be either a 0 or a 1 - Bits are used in groups - A group of eight bits is referred to as a byte. - Number of different values for bytes = 2^n

Switches

- Each dial has 10 different states (0 - 9). - Physically creating circuits that distinguish all states is complicated. - Would need to distinguish 10 different strengths of electricity (voltages). - Switches are simple: ○ Each switch is off or on (0 or 1). ○ Physically creating the circuits is easy. ○ Switch off: electrical current cannot flow. ○Switch on: electrical current can flow.

Basic features of word processors- editing text, clipboard, paragraphs

- Editing text: ○ Spelling and grammar checker ○ Aligning text using the margins and ruler - Clipboard: ○ Cut, copy, paste - Formatting: ○ Changing font ○ Change document settings ○ Format paragraphs - Font: window lets you change: ○ Font ○ Style (bold, italic) ○ Size (in points) ○ Colour ○ Effects (strikethrough, subscript superscript) - Paragraphs: window lets you change: ○ Alignment ○ Indentation ○ Spacing ○ The 'Line and Page Breaks' tab let you adjust how the paragraph behaves between pages

Email and its History

- Electronic Mail; a system for sending and receiving messages over the Internet - An asynchronous means of communication ( two parties in different places communicating in different times) - Necessary to know the address of the recipient in order to send an email message - 1960s: initially, people would leave messages for each other on a mainframe - However, there was no way to send messages to people using other mainframes - 1969: ARPANET connected mainframes together, providing the foundation for email - 1972: Ray Tomlinson sends the first email, with addresses using the @ symbol 1976: email makes up 75% of ARPANET's traffic

mail - privacy

- Email is not a very secure means of communication ○ Can be read in transit ○ Can be read by the mail server administrator or stolen from the mail server - Email in employment ○ Generally, employers reserve the right to read your emails on the company's email system - Making email more secure ○ Email encryption tools such as PGP (scrambled data) >> Some email clients have encryption functionality ○ Keep your account details secure and use 2FA

Mood Disorders

- Extensive evidence documenting a relationship between depression and technology. ○ Excessive texting, viewing video clips, video gaming, chatting etc. - Depression may be transmittable through technological interaction. ○ Consumption of depressing media, particularly movies and music can induce a negative affect. ○ "emotional contagion

Standards

- File formats sometimes follow a standard; an agreed way of encoding data (eg. webpages use the HTML5 standard) - Open Standard: ○ Published openly ○ Free to use ○ Eg. HTML, PDF - Proprietary standard ○ Owned by a company ○ Others can use the standard if they pay for a licence Eg. MP3

Online bullying- 2 options

- First option: complain to the Approved Agency ○ Approved Agency is Netsafe; a non-profit organization ○ If the complaint is genuine, Netsafe will use "negotiation, mediation, and persuasion (as appropriate) to resolve complaints" - s8(1)(c) ○ s11: after Netsafe has assessed the complaint, the person can apply to the District Court for an order >> s12: Court must be satisfied that the communications principles have been breached (s6) and that the person has been harmed >>Orders under sections 18 and 19 include: u Take down material, cease conduct, publish a correction, publish an apology - Second option: person or Netsafe can complain to online content host (a person who controls "an electronic retrieval system") where the harmful digital communication can be accessed ○ Includes social media sites, blogs, search engines ○ s24: when a host gets a complaint, it must try to contact the author of the harmful digital comm. >> If the author responds and refuses to remove the material, then the host can't do anything >> If author doesn't respond or the author agrees, the host must take down the content within 48 hours ○ s23: following this process protects the online content host from any legal liability arising from the harmful digital communication

Scalable Vector Graphics

- Format for representing vector graphics images • Open standard created by W3C • New, gaining popularity •XML, text file similar to HTML

Forums

- Forums are an online discussion group about a particular topic - A form of asynchronous communication - Different kinds of forums: ○ Class forums for university courses ○ Apps have forums where users can help each other (e.g. OpenOffice forum) ○ Forums for discussing different topics (e.g. forum on airplanes) Moderator: a forum user who can edit, delete or move posts or threads to help keep the forum tidy and organised

The Internet's backbone

- High-capacity fibre optic cables laid on land and under the sea - Owned by companies who rent out capacity on the cables - They connect countries together to form the global Internet so are extremely important - Having multiple backbone cable connections provides extra capacity and redundancy

HTTP

- HyperText Transfer Protocol; used by web browsers to request resources (eg. webpages, images, sounds) from a web server - There's also HTTPS = HyperText Transfer Protocol Secure ○ Encrypts the HTTP connection using TLS (Transport Layer Security) ○ Becoming essential for websites to use HTTPS to keep user information secure - Error 404 if it cannot be found on server

Hypertext

- Hypertext is basically text with links ○ Allows associations to be made between pieces of text - Ted Nelson - the Xanadu Project (1960s) ○ First computer-based hypertext implementation Although developed in the 1960s, the first public release was in 1998 - Vannevar Bush - "As We May Think" (1945) ○ Bush described a device called a memex, which could store text and links within the text

Protocols - TCP/IP, UDP

- IP - Internet Protocol: ○ A unique identifier for computers on the Internet ○ Defines routing information ○ v4: 32-bit addresses (eg. 192.168.1.1), ran out of addresses >> 4 groups of 8 bits >> biggest number is 255 (2^n , 2^8=256 and the smallest is 000 (exam) ○ v6: 128-bit addresses >> 8 groups of 16 bits >> 0-9, a, b, c, d, e, f >> 0000 is the smallest and ffff is the largest - TCP - Transmission Control Protocol: ○ Divides the message into packets (typically about 1 KB) ○ Checks that all packets arrive (error detection) ○ Ensures packets are not sent faster than they can be received (flow control) ○ Combines packets to recreate the data - UDP - User Datagram Protocol: ○ Lacks error detection and flow control, better suited to realtime data such as video streaming, Skype calls etc.

Displaying images on printer vs screen

- Images are displayed on an output device • Screen / Printer • Physical devices have limitations

Deficits in Social Skills

- Increased interaction with technology has led to a reduction in human interaction. ○ Face-to-face communication skills are negatively affected. u - Visual cues are an important part of face-to-face communication. ○ Includes facial expression, eye contact, tone of voice, posture, and spatial distance. ○ Need to be able to modify one's own behaviour in response to the reactions of others. - A 2014 study of 105 U.S. children was carried out. ○ 51 children in the test group did not use digital devices for 5 days - only face-to-face communication. ○ 54 children in the control group continued to use their digital devices. ○Test group recognition of nonverbal emotional cues was significantly better than that of the control group

Analogue vs digital information

- Information in the real world is continuous (continuous signal) - Information stored by a computer is digital (represented by discrete numbers)

Instant messaging

- Instant Messaging (IM) is a way of immediately sending messages over the Internet - A synchronous means of communication ( different places but same time) - In 2015, there were around 3.2 billion IM accounts. Whatsapp and FB Messenger were the most popular IM apps - Some IM apps offer end-to-end encryption for conversations (eg. Telegram, FB Messenger) - Sender's IM client connects to the server

Plagiarism

- Involves taking another person's ideas, words or inventions and presenting them as your own. - It includes: ○ paraphrasing or summarizing another person's work ○ using graphs, images or other media from someone else's work - This is a serious breach of academic integrity - All material, whether directly quoted, summarised or paraphrased, must be acknowledged properly.

Online anonymity

- It is impossible to be completely anonymous on the Web - However, it is possible to remain fairly anonymous on the Internet ○ Used to be difficult to associate an IP address with a person's computer ○ Easy to give fake information when creating an account on a website ○ Most websites don't perform an ID check on their users - Anonymity on the Internet is being eroded: ○ Advertisers are able to effectively track users' preferences and browsing habits E.g. fingerprinting computers better than using cookies ○ Websites demand more personal information and keep track of users' activities ○ Laws require ISPs to keep a record of the IP addresses assigned to users ○ Governments are expanding their online surveillance powers

User interfaces: Command line interface vs Graphical user interface

- Key difference is that a CLI is text-based while a GUI graphically-based Command line interface: - User enters text commands to perform tasks - Can complete tasks very quickly by combining commands - Can be difficult to use the text commands if you don't know or understand them Graphical user interface: - Users perform tasks using the software's graphical elements (e.g. windows, pointers, icons, menus) - Generally easy to use, especially for new users - Can be inefficient for experienced users, but keyboard shortcuts help to make GUIs more efficient

Hearing Loss

- Listening to media through headphones or earbuds for prolonged periods of time at high volume can cause permanent hearing loss. - A 2005-2006 study reported that 19.5% of American adolescents aged 12 to 19 suffered from hearing loss. ○An increase of 33% from that reported in 1988-1994. ○Some of this increase may be attributable to headphone/earbud usage. - Prevention: ○ Lower volume. If other people can hear the music you are listening to it is most probably too loud. ○ Limit exposure. Moderate noise on a regular basis can lead to hearing loss.

Types of networks

- Local Area Network (LAN) ○ Operates within 1 km radius ○ Client-server or peer-to-peer configuration ○ Can connect multiple LANs to form an intranet - Wide Area Network (WAN) ○ Distances over 1km - The Internet Network of networks that use the TCP/IP protocol

Malware and viruses

- Malicious software (malware) can damage a user's computer, data or apps - Viruses attach themselves to other programs, where they can cause damage and spread to other computers - Protect your computer and data with anti-virus software and a firewall

Multimedia and hypermedia

- Multimedia: the integration of many forms of media (text, video, sound, images etc) - Hypermedia: the creation of links between multimedia content

Circuit-switching network

- Nodes are connected physically via a central node - Used by the telephone network - Originally, switchboard operators had to manually connect phone calls, today this is done electronically

Binary vs Decimal number system

- Numbers are used to represent all information manipulated by a computer - Computers use the binary number system ○ Binary values are either 0 or 1 - We use the decimal number system: ○ 0-9 are decimal values

Vector Graphics

- Object-oriented graphics • Objects created independently • Defined by mathematical formulae - Advantages • Very small memory requirements • Memory independent of the image size • Scale to any size without loss of quality

Filter bubble of sear engines

- Occurs when a search algorithm offers personalised results, which limits the diversity of information presented to the user - Personalised search results can help people to find relevant information - However, it also risks isolating people within their own bubble of information

ARPANET

- October 1969: ARPANET is completed with four nodes - 1973: Norway connects to ARPANET via satellite, followed by London via a terrestrial link - 1983: TCP/IP implemented in ARPANET - Networks similar to ARPANET sprang up around the USA and in other countries - 1984: domain name system (DNS) implemented - 1985: NSFNET was established - 1989: Waikato University connects to NSFNET - 1990: ARPANET is formally decommissioned - 1991: World Wide Web (WWW) created at CERN (European Organization for Nuclear Research) by Tim Berners-Lee - 1995: NSFNET is retired Don't need to know years, just the chronological order

How much memory is required? for colour

- One binary number used for each pixel (2^n) • 1 bit 2 colours • 2 bits 4 colours • 4 bits 16 colour • 8 bits 256 colours • 16 bits 65536 colours • 24 bits 16,777,216 colours - How many bits are required for a 16 colour image 100 pixels wide x 8 pixels high? • 100x8x4 = 3200 bits = 400 bytes (8 bits= 1 byte) - An image using 24 bit colour, 1000 wide x 1000 high (1 Megapixel)? • 3 MB

File sharing

- One of the Web's main aims was to help people easily share information e.g. dropbox, google drive - Peer-to-peer (P2P) networks provide another way of sharing files - P2P networks use the BitTorrent protocol to enable computers to connect to each other and share data

RefWorks

- Online reference manager; used to manage references and insert them into your documents - Bibliographic information can be entered manually, loaded from the UoA library catalogue or loaded from a database - References are generated in accordance with a wide variety of referencing styles - Advantages: ○ Web-based, so you can access it from any computer, regardless of operating system ○ Supports a range of databases and referencing styles ○ The Write-n-Cite plugin for Word allows you to insert references directly from Refworks

Narcissism

- Personality trait characterized by a grandiose sense of self-importance. ○ Engage in self-promotion, vanity and superficial relationships. - Younger people show a stronger urge to report their activities and believe their social media audience care about them. ○ A 2009 study of 16000 college students in the US found that they scored substantially higher on the Narcissism Personality Inventory than their cohort 20 years ago. - Studies have suggested social media exacerbates and even encourages narcissism. ○ Users may tailor their profile pictures, status updates, biographies and even lists of friends in order to appear more attractive.

Printing Bitmaps

- Printer and Screen have different sized dots • Scale (resample) the bitmap to ensure it looks good on both On screen: lower resolution, on printer increase resolution

Email - protocols

- Protocol: a standard for communicating - These email protocols are used by email clients (eg. Outlook, Apple Mail) to send and receive email ○ Webmail services such as Gmail and Hotmail use the same protocols - One for sending emails - SMTP - Two for receiving emails - POP3 and IMAP - SMTP - Simple Mail Transfer Protocol: ○ Used to send emails from an email client via the email server

Protocol

- Protocol: a standardised method of communication - Ensures that the sender and receiver can communicate properly - Protocols include rules for: ○ Opening and maintaining a connection ○ Sending and receiving data ○ Ending the connection - Common Internet protocols: ○ TCP/IP: transports data reliably ○ UDP: transports data faster but less reliably ○ FTP: used for transferring files over a network ○ HTTP: used for client/server communication such as transferring web pages ○ POP3, IMAP, SMTP: used for email - Many protocols used in networking are defined in a RFC (Request for Comments) document ○ RFC 791: IP ○ RFC 2616: HTTP (don't need to know numbers

Proxy, cache, firewall

- Proxy: sits between client and server so it can intercept and process requests ○ e.g. blocked websites at high school - Cache: stores recently requested resources so they can be accessed quickly ○ A proxy can use a cache to store recent requests, enabling it to process requests faster Firewall: prevents unauthorised access to a private network

Redundant Array of Independent Disks (RAID)

- RAID pools HDDs/ SSDs together to form a larger, more reliable data storage mechanism - Each RAID configuration has its own strengths and drawbacks - Commonly used in servers Two configurations: ○ RAID 0- data stripes used to increase speed ○ RAID 1- data redundancy used to increase reliability ○ RAID 10- combines RAID 0 and RAID 1 together

Encoding information

- Real world information is stored by a computer using numbers - Visual information (not numerical converted into numbers by computer): 1. Give each pixel colour a number 2. Let the computer draw the numbers as coloured pixels e.g. black=0

Computer Vision Syndrome

- Results from focusing eyes on a computer or other display device for long, uninterrupted periods of time. - Symptoms of CVS include: ○ Dry eyes ○ Blurred/double vision ○ Eyestrain ○ Red/irritated eyes - Treatment/Prevention: ○ Proper lighting within computer workstation area ○ Appropriated screen distance and position ○ Work breaks ○ Lubricating eye drops

Displays (colours)

- Screens use a combination of Red, Green and Blue lights - use one byte (8 bits) for each colour • 256 different levels of red brightness • 256 different levels of green brightness • 256 different levels of blue brightness

Privacy of search engines

- Search engines are gathering vast amounts of information about our searches and ourselves ○ This information is generally used for advertising purposes - While you can search anonymously, search history can be used to identify individuals

Storing decimals numbers in a Computer

- Series of dials: ○ Each dial goes from 0 to 9 - Information is stored digitally ○ Finite number of states -10 per dial ○ No in-between states - Decimal number system: ○ 1st dial from right: 10^0 ○ 2nd dial from right 10^1 ○ 3rd dial from right 10^2 etc.

Blogs

- Short for web log, a website where posts are displayed in reverse chronological order (ie. newest posts first) - Around 150 million blogs worldwide on a range of topics from personal to political - Different kinds of blogs: photo blog, video blog (vlog), audio blogs (podcasts) - Online blogging platforms include Blogger, Wordpress, Silvrback

Online bullying

- Some people take advantage of online anonymity to bully and harass others online - One UoA study found 11.5% of people in NZ over 18 have experienced online bullying - Online bullying is a growing problem among youth. Our 'always online' society makes it difficult to avoid online bullying - The Harmful Digital Communications Act 2015 (HDCA) is one response to this growing problem ○ s3: purpose of this Act is to: >> Deter and mitigate harm caused by digital communications >> Provide redress to victims of harmful digital communications - s4: key definitions ○ 'digital communication' means "any form of electronic communication" - includes texts, emails, IM, forum posts, Snapchat etc. ○ 'harm' means "serious emotional distress" u Two main avenues of redress under the HDCA

Software failure

- Sometimes errors occur in software, which lead to crashes or error messages - Generally can't be fixed by the user but you can: ○ Google your problem to see if there's a solution ○ Report the problem to the developer ○ Check for program updates since developers include bug fixes in these updates

Bitmap Graphics

- Storing pictures digitally • sample the image (divide into dots) • Image resolution (number of dots) 200 pixels by 250 pixels, resolution= 50,000 pixels

General Solutions for Healthy Use of Technology

- Take breaks both large and small. - Moderate your social media presence. - Give your work or entertainment space an ergonomic makeover. ○ Pay attention to lighting, chair, display position etc. - Maintain a healthy lifestyle. ○ Appropriate diet ○ Exercise ○ No smoking

ascii binary

- Text you type: YES - The text in ASCII: 89 69 83 - Binary stored by the computer: 1011001 1000101 1010011

WWW vs Internet

- The Internet is a global system of interconnected computer networks. ○ Carries a vast range of resources and services. - WWW is a global collection of documents and other resources accessed through the Internet using HTTP - one of many Internet communication protocols. ○ Documents are linked via hyperlinks and are identified by their URL

Cultural dominance

- The Internet was popularised in the USA and English is the dominant language online - Other cultures now have a strong presence and influence on the Web ○ Chinese social media platforms, eg. Weibo, Wechat ○ K-pop - Diverse control over key pieces of Internet infrastructure. Examples: u We've seen backbone cables are mostly owned by private companies

Censorship on the Web- classification, blocking software, web filter

- The Office of Film and Literature Classification is responsible for determining the age classification of publications - Three levels of classification: ○ G, PG, M: publication can be viewed by anyone, caution needed around PG and M ○ R13, R15, R16, R18: publication can only be viewed by people of the given age and over ○ RP13, RP16: publication can only be viewed by people of the given age and under if accompanied by their parent - Any publication on the Web (movies, games, music etc) is subject to NZ's censorship laws when accessible in NZ ○ Sometimes, a publication is classified as objectionable, meaning it can't be owned or sold in NZ >>Objectionable publications are those with extremely sexual, violent or offensive content - Software can help to restrict access to certain content on the Web - Blocking software ○ Uses a blacklist or whitelist of IP addresses to determine which websites can be accessed and which websites should be blocked ○ Eg. Department of Internal Affairs DCEFS - Web filter ○ Prevents access to websites based on their content (eg. image/video screening, keywords, malware etc) ○ Eg. K9 web filter, tutorial for running a filter on a proxy

Central processing unit (CPU) (HINT)

- The brain of a computer. Processes data in a computer (as input and generates output) using its instruction set - Performance can be measured in: ○ Instructions per seconds ○ Clock speed (Hertz- Hz) - CPUs must be kept cool, using a heatsink and fan - Transistors ○ Billions of them arranged as a chip responsible for processing instructions for the CPU - Moore's law ○ "the number of transistors on a single integrated circuit doubles approximately every 18 months, while the price remains the same." e.g. in 3 years, CPUs will be 4 times faster, 15 years 1000 times faster. Powerful= 2^n (n=no. of 1.5 year periods) ○ More difficult to keep up with Moore's Law as we reach the limits of CPU fabrication technology Other measures ○ Power efficiency and heat are just as important as clock speed ○ Modern CPUs have multiple cores (split a task in 4 cores, 1/4 time), increasing their processing capacity ○ New kinds of processors such as system on chip (SoC) are commonly used in mobile and embedded devices

Instant Gratification

- The desire to experience pleasure or fulfilment without delay or deferment. ○ You want it, and you want it now. - Always online digital devices have raised the expectation for immediate gratification. ○ E.g. expecting immediate responses to social media posts or texts. - Has resulted in: ○ Increased impatience ○ Unrealistic expectations ○ "checking" behaviour

Motherboard

- The main circuit board to which all components are connected, allowing them to communicate with each other

Encyclopedia Britannica

- This popular printed encyclopedia now only exists online - Articles have generally been checked for accuracy and correctness ○ Users can't directly edit the articles but can suggest changes - Britannica runs a Publishing Program, whichallows people with expertise in their field to publish articles on Britannica

The WWW project

- Tim Berners-Lee worked at CERN in the 1980s - Physicists performing research at CERN found it difficult to share their research with each other - Berners-Lee thought he could solve this problem using hypertext and wrote "Information Management: A Proposal" outlining his idea in 1989 - Tim Berners-Lee built the first website in 1991 at CERN. - In June 1993, Mosaic was released; the first widely used web browser - By Oct 1993, there were 500 web servers around the world ○ By this point, Berners-Lee realised the WWW had to be freely available so he convinced CERN to make the source code public - In 1994, Berners-Lee established the World Wide Web Consortium (W3C), which creates standards for the WWW

Application Software

- Two kinds of software: system and application - Very wide range of application software e.g. web browsers, email clients, office software, graphics software, music software, security software, software development tools

File sharing copyright

- Unfortunately file sharing on P2P networks is used for copyright infringement ○ Copyright protects an author's work from being copied without their permission ○ One of the most famous P2P networks is The Pirate Bay - The Copyright Act 1994, sections 122A to 122U, provides a way for copyright holders to complain about file sharing on P2P networks - Up to three notices are given to the infringer by their ISP in a nine month period - Infringer can challenge each notice - When an enforcement notice is issued, the infringer can be penalised: ○ Copyright Tribunal can impose a penalty of up to $15,000 ○ District Court can suspend the infringer's Internet connection for up to 6 months

Email- spam (- Unsolicited Electronic Messages Act 2007)

- Unsolicited Electronic Messages Act 2007 ○ Aim: reduce the harm caused by spam, require an unsubscribe feature and deter people from sending spam - The Act regulates commercial electronic messages; any message that promotes a good or service ○ Electronic message is any message sent using a telecommunications service (eg. email, fax, txt) - The Act applies to anyone who lives or does business in NZ - The Act prohibits: ○ sending an unsolicited commercial electronic message with a NZ link ○ sending a commercial electronic message without sender information ○ sending a commercial electronic message without an unsubscribe function - Penalties include: ○ Fines of up to $200,000 ○ Payment of compensation to people affected by the spam

Email- spam

- Unsolicited, bulk email containing promises of money, fame, free prizes etc. ○ Name comes from the Monty Python Spam sketch - A major problem: 2010, approx. 80% of emails were spam - Some spam emails contain attachments or links that can infect a computer with malware - Most email providers have spam filters that divert spam emails to the Junk folder

File extension

- Used by the operating system to determine a file's format

Malware: malicious software- viruses, worms, trojans, spyware, logic bombs

- Viruses: inserts itself into another program; runs and spreads itself when the program is opened - Worms: similar to viruses except they don't need a program in order to run; spreads by itself - Trojans: malware disguised as legitimate software - Spyware: runs in the background, monitoring the user's activities and sending the info back to the operator ( tracks passwords when using bank accounts) - Logic bombs: malware deliberately inserted into a program which runs when a certain condition is fulfilled - The best protection against malware is a good anti-virus program and the use of safe browsing practices: ○ Don't click on unknown links ○ Delete spam messages ○ Don't open unknown attachments

Webpage, website, web browser, web server definitions

- Webpage: a hypermedia document on the WWW that is usually accessed through a web browser - Website: a collection of webpages usually on the same topic or theme - Web browser: application software used to access content on the WWW - Web server: a computer with software that makes files available on the WWW

WYSIWYG

- What You See Is What You Get - WYSIWYG - The document created using the word processor's GUI is the same as the document that comes from the printer - Computer code is NOT WYSIWYG (eg. wiki markup, LaTeX code, HTML)

Wikipedia history

- Wikipedia is the best known wiki. Launched in 2001 by Jimmy Wales and Larry Sanger >> Today, it has over 5.3 million English articles with around 20,000 articles added each month >> Funded by grants and public donations >> Wikipedia runs on the MediaWiki software platform and is hosted on around 400 servers

Logging browsing history

- computers keep a record of the webpages accessed by a client: 1. Web browser 2. Computer's operating system 3. ISPs ○ They hold varying amounts of information u In Australia, ISPs must retain information about their customers' web usage for at least 2 years 4. The web server

Sound information

1. Give each sample a number (height of green box) 2. Let the computer move the loudspeaker membrane according to the samples

Wiki Markup- paragraphs

A new line is ignored while a blank line creates a new paragraph

Wikipedia- advantages, disadvantages,

Advantages: ○ Everyone can access and contribute to Wikipedia ○ Easy to use ○ Quick to develop material ○ Enormous amount of topics and information available Disadvantages: ○ No direct quality control ○ Bias in some articles ○ Information changes rapidly ○ Vandalism is a real problem

Blogs- advantages and disadvantages

Blogs - advantages: - For the blogger: ○ Blogs generate revenue through advertising. ○ May provide opportunity to cross-over into mainstream media. - For the reader: ○ Blogs can also be sources of news ○ Blogs gave people a voice during political unrest Blogs - disadvantages: - Can provide too much information about yourself ○ Extremely difficult to erase any information that has been placed on the Internet because information is easily duplicated - Blogs can contain incorrect information or personal opinion, so can be unreliable sources of information - Some people use blogs or the comments section on blog posts to harass or insult other people

Copyright vs Patents

Copyright - Software is protected by a range of IP rights - Protects the expression of an idea - literary works (includes software) is protected by copyright - author owns the copyright - copyrighted material can be used by others if they have a licence Patents - Protect an idea from being copied by others - a computer program is not an invention and therefore can't be patented - Exception for software in embedded systems

Labels for links

Easier for readers to understand for internal and external links

word processors- formatting symbols, page breaks, section breaks

Formatting symbols: are non-printing characters that are used to mark spaces, paragraphs and page breaks etc. in a document Page breaks - Page breaks mark where the current page ends. Anything below the page break is moved to the next page of the document Section break - Section breaks mark the point where one section ends and a new section begins Individual sections can have their own formatting - Two kinds of section break: ○ Continuous: the new section begins on the same page as the original section ○ Next page: the new section begins on a new page after the original section

Hard Disk Drive (HDD) vs SSDs

Hard Disk Drive (HDD) - Stores data on spinning magnetic disks. Data is read and written by moving heads - Advantages: ○ Cheap storage medium ○ Widely used and supported ○ Can have very large capacity drives ○ Long operating life - Disadvantages: ○ Noisy operation (moving parts) ○ Consume more power than SSDs ○ Fragile, needs to be handled carefully SSDs - Stores data on flash memory, the same technology used in USB drives - Advantages: ○ Silent operation ○ Higher read/write speeds when compared to HDDs ○ Low power usage ○ More durable ○ Use less space - Disadvantages ○ Costlier than HDDs ○ Can wear out faster than HDDs

Input devices vs Output devices

Input devices - Peripherals that allow the computer to receive input from the outside world, mainly from the user - Common input devices: mouse, keyboard, webcam, voice recognition, RFID tags, biometric scanners Output devices - Peripherals that present information processed by the computer to the user - Include: computer, printer, speakers, touchscreens, virtual and augmented reality

Issues of email

Issues - 1. attachments - An attachment is a file that is included within an email message, IM message or even a forum post - Attachments may contain malicious content so never open an attachment unless you are sure it is from a reliable source ○ Another precaution is to scan the attachment using an anti-virus program - Attachments have been the main way that Cryptolocker ransomware has spread Issues - misrepresentation - People can misrepresent themselves using electronic communication ○ Phishing emails claiming to be from your bank ○ False profiles on dating apps and social media - Always worth double-checking a message with the purported sender if you're suspicious Issues - Netiquette - Etiquette on the Internet; what is socially acceptable when communicating online e.g. Having a greeting and signature in your emails, Not using your cellphone in libraries and quiet spaces

open source software

Open source software - Software that is free to use and whose source code is public ○ Anyone can use or modify the source code ○ Anyone can create a derivative work from the source code - Open source movement started in the late 1980's and outlined in the Open Source Definition - Open source software licences (eg. Apache, GNU) are not as restrictive as commercial software licences e.g. open office

POP3 - Post Office Protocol v3 vs IMAP

POP3 - Post Office Protocol v3: - Emails downloaded from the server to the email client. Emails are then deleted from the server - No Internet connection needed to read downloaded messages - Disadvantages: ○ If messages are deleted in the email client, then they are lost forever ○ Difficult to access your email from different devices IMAP - Internet Message Access Protocol: - Downloads a copy of emails to the email client and keeps emails on the server - Emails can only be read when online, although most email clients can store a copy for offline access - Provides other helpful features such as folders - Designed to allow users to access their emails from multiple devices

Decimal and Binary prefixes

Prefixes - A group of 8 bits is byte, a group of 4 bits is a nibble - Bytes are the common unit of measurement for memory capacity - Decimal prefixes are preferred because they are easier to calculate, however binary prefixes are more accurate Decimal Prefixes - e.g. 128 MB= 128,000,000 bytes

Primary Memory vs Secondary Memory

Primary Memory: - Used to store data for quick access by CPU - Main form of primary memory is Random Access Memory (RAM) - RAM is volatile memory (data stored by RAM lost when power supply is off) - More RAM improves a computer's speed by providing more quick access memory - Capacity is measured in bytes, clock speed measured in Hz - Types: DDR4, SDRAM Secondary Memory: - Used to store files for repeated access over time - Also known as non-volatile storage: the storage medium retains its contents without needing a supply of electricity - Many forms of secondary storage: ○ Hard disk drive (HDD) ○ Solid state drive (SSD) ○ CDs, DVDs, Blu-ray ○ USB drives, external HDDs

Proprietary software

Proprietary software: 1. Shareware ○ User has a trial period in which to evaluate the software, and purchase it if they want ○ Nagware: software keeps reminding the user to purchase the full version ○ Crippleware: software that works with limited functionality until the user purchases it ○ Freemium: software with a free tier and paid tier e.g. spotify 2. Freeware ○ Software is free to use but source code is not publically available ○ Freeware can be a loss leader (initial loss, but hope other will try their other products) or adware ○ Some freeware is known as abandonware; software no longer maintained but still available 3. Commercial: Software that a user must purchase to use

references and citations

Reference ○ Provides details about the source. ○ Should enable reader retrieval of source. ○ Found at the end of a document. Citation ○ Tells readers where the information came from. ○ Within the text.

Compressing Images Algorithms

Simply reducing number of colours - Graphics Interchange Format (GIF) • Lossless method • 256 colours • Good for graphics (fewer colours), poor for photos (too many different colours) • Uses an algorithm that was patented - Portable Network Graphics (PNG) • Replacement to GIF • Lossless method • 16 million colours (24 bit) •Good for graphics, poor for photos - Joint Photographic Experts Group (JPEG) • Lossy method • 16 Million colours (24 bit) • Averages nearby colours • Different degrees of compression • Good for photos, poor for graphics (sharp colour differences of boundaries)

To, and CC: vs Bcc

To, and CC: - All recipients in the two fields will appear in the email itself and are the same function wise. - All recipients receive the email. - If you expect an answer you use the "To" field. Use CC field if you don't require a response. Bcc: - Is essentially the same as the "to" and "cc" field but the email addresses do not appear in the email (can be used when you do not want people to know who else you sent the email to).

wikipedia- vandalism, reliability

Vandalism ○ Wikipedia has a number of automated and manual systems for addressing vandalism ○ Bots: vandalism is automatically detected and reverted by a bot called ClueBot NG ○ Recent change patrol: a group of people monitor the Recent Changes page to modify or remove vandalism >> Can also modify or remove edits that don't meet Wikipedia's standards ○ Watchlists: registered users can watch a page that they have created/edited or are interested in, allowing them to watch for vandalism ○ Reader-reported vandalism: readers can address vandalism by: >>Reverting to an older version of the page >> Warning the vandal that their actions have been noted >> Report the vandal to Wikipedia administration Reliability ○ Generally, Wikipedia articles on academic topics are more accurate than articles on pop culture and politics Maybe because these articles are more subjective or opinion-based?

Resizing bitmap images

When you make the image bigger (bitmap), resolution appear lower - For higher resolution: make four pixels of each of one colur pixel of the original - The sample at lower resolution: take the four pixels of original and average the colours

Other wikis

WikiVoyage - Travel guide with entries for countries, cities, areas, sights Wikia - Collection of Wikis, anybody can create wiki on any topic - Focus on gaming and entertainment topics - ~10 million entries altogether WikiMapia - Combination of Google Maps and an extra layer of polygons that mark interesting areas, buildings etc. - ~13 million entries WikiHow - Extensive collection of how‐to guides - Articles often include media such as photos and videos

Uniform Resource Locator (URL)

https://www.cs.auckland.ac.nz/~andrew/teaching.html - Protocol: https ○ other common protocols: ftp, http - Domain: www.cs.auckland.ac.nz ○ Can be a domain name or an IP address - Path on server: ○ /~andrew/ - Resource: ○ teaching.html

The Tor Project

○ A network of servers that use onion routing to obscure the path that packets take when moving from sender to receiver ○ Onion routing involves sending the packet along a random path through a set of encrypted relays ○ Need to use the Tor browser in order to browse the Web over the Tor network ○ By protecting data as it is being transported, Tor makes it difficult to intercept data or find the source/destination ○ However, it doesn't protect a user's computer from cookies or from being fingerprinted ○While the extra anonymity provided by Tor is useful, it has also been misused (eg. the Silk Road)

Links

○ Internal links: used to link to other pages in the wiki (in the same page)- two square brackets External links: used to link to other webpages- URL

Lists

○ Unordered lists: >> Uses the * character in front of each list item >> Use multiple * to create sub-lists ○ Ordered lists: - Uses the # character in front of each list item - Use multiple # to create sub-lists when there is an ordered sublist for unordered list *# when there is a unordered sublist for ordered list #*