Wendy G Lehnert,
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Wendy G Lehnert, “Internet 101, A Beginners Guide to the Internet and the World Wide Web”,Addison-Wesley, 1998 The Internet is simply a network of computers, linked together all over the world. A “network of networks”. size, history http://www.isoc.org/internet-history/ brief.html
Slide 2:Ownership, no rules “membership” by connecting to an ISP Packet-switching model (origin, destination, file name, packet number) LAN or WAN Every network has a IP address (URLs) Protocol://host computer/path/filename major domain name edu,com,org,net,gov country code au uk Protocol defines the type of connection you make to the Internet. WWW-http
A set of rules for communicating the end points in a telecommunication network use when they send signals back and forth regardless of computer type need internet connection, appropriate software IP-internet protocol, TCP/IP-transmission control protocol, HTTP-hypertext transfer protocol, SMTP-simple mail transfer protocol, FTP-file transfer protocol, telnet, (video protocol?) how we make connection http:// ftp:// telnet://
Slide 4:Caches and proxy servers
The cache is simply a temporary storage area where your browser stores files that it downloads. Using BACK button. In Internet Explorer: temporary internet files under windows folder Proxy server - cache provided by ISP, invisible to user, intermediary between user and Internet, filters requirements, looks at local cache, requests server on Internet on behalf of user
In computer networks used to control the material that passes between a network and the outside world. Mixture of hardware and software that acts as a buffer between your network and the rest of the Internet. The firewall controls access into and out of your network.
Slide 6:Web Pages
Web page uses hypertext markup language view-page source home page (start of the book) Frames - designated sections of a page with different source, URL: right click-properties internet address - address of network e-mail address - address of account web page address - address of file
Slide 7:Searching the Web
Search Engine is a Web page which has been set up to allow you free web searching and support service. Altavista: Advertising, find good content search engine use a spider or crawler which work its way around the Web from link to link, collecting data to create a database. Spider/crawler, a database, software query
Spider captures references to many web pages out of date, moved location, account expired syntax use on queries “…..”, multiple words, comput*, be specific, and/or/not, + - hitlist, directory search engines (index of categories ), key word search engines
Internet Explorer- Favorites Netscape Communicator- Bookmark URL and title, housekeeping use official sites referencingbooks: title, author, publication details, page number referencing Web pages: URL, author, date found
Slide 10:Search within page:edit-find, search button evaluating search engines: database, specific, search facilities being found when creating a site: query words in title or start, close together, many instances of query words, list of search engines, requirements, let them know, include links http://www.albany.edu/library/internet/second.html
Slide 11:Word Processing (2)
Document (.doc) has content ( text, graphics, charts) and form (appearance). “This is a text file “Text.txt contains 21 characters (the 19 characters that we wrote, plus an end-of-line character and an end-of-file character), Word.doc contains 19456 characters! RTF contains 2582 characters. RTF (Rich Text Format) it is a file format that allows you to exchange document files in text format between different versions of the same word processing software, Different word processing software packages, Different operating systems.
Slide 12:Word Processing (3)
Save, Save As, Autosave .tmp file keeps new changes before saving ASCII and Unicode show/hide on toolbar for structure of layout sections, margins in page setup headers and footers, make tables, help option (contents-index).
RAM (random access memory) and ROM( read only memory) with documents Clipboard - temporary memory space copy-paste cut-paste Deleting, Undo, Redo button Find ( can use * ? ) and Replace Insert-symbols (special characters) Clip Art and WordArt
Slide 14:Tools in Word
Spell checkers: language, technical and proper names, grammar errors of context, use of add button, Grammar Checker - Auto Correct - Thesaurus Properties of files to see statistics
HTML is the language that most Web browsers use. We say that most web pages are coded in HTML
Slide 16:HTML and Web Browsers
In this case, the "compiler" or document handler is your Web browser (Internet Explorer or Netscape) which is designed to handle text documents encoded with HTML tags.
Slide 17:How to start HTML
<html> <head> <title>First Marked up Document</title> </head> <body> ………… </body> </html>
<body background="htmlbg.gif" bgcolor="#ffffcc" link=#ff7777 text=#cccccc> Declares background and default colours of background, text, and links in the web page.
the beginning and end tags are identical except for the forward slash (/) <H1>Make your own Heading</H1> <h2> smaller <h3> and smaller <h4> and smaller <h5> and smaller and <h6> smallest
Slide 20:Formatting text
<font color="#FF0000"><font size=+2> ………….. </font></font> <b><u><i> comp123 </i></u></b> <hr WIDTH="100%"> draws a line <center> </center> centres text <br> and <p> line spaces
<img SRC="Aobo.gif" height=118 width=350> Make sure picture is in same folder as web page (html file) The tag <img> has a number of attributes including "width", "height", "align“.
<a href="http://www.opera-australia.org.au/”>link to opera page</a> <a href=“page1.html”>link to Web Page 1</a> <a href =“#Top”> go to top of page</a>
<li>............list item(puts a "dot" before each item) <ul>............unnumbered list <ol>............ordered list (numbers each item) <ul>…</ul> or <ol>…</ol> <li>item 1</li> <li>item 2</li>
<table> .... </table> define a table <th> specifies table heading <tr> specifies rows in a table <td> ... </td> define data contained in a cell <table border=4 width=100%> <th>Heading1</th><th>Head Cell 2</th><tr> <td>Cell 3</td><td>Cell 4</td><tr> <td>Cell 5</td><td>Cell 6</td> </table>
Picture - controls a selected image. You can use this to adjust the brightness or contrast of an image, or carry out other functions. Office Clipboard - It used to be a fact that the clipboard could only hold one thing at a time. Using the Office Clipboard, as outlined in the text, allows you to store up to 12 different items on the Clipboard at once. Tables and Borders - This can be used as another way of controlling the tables in your document; you don't have to go to the Table menu.
Scaleable Fonts:can be adjusted to any size, and can be printed well on any printer that prints graphics. Printer fonts are fonts that are built into the printer. True type or postcript fonts Screen Fonts: In order to display a font on your screen, the font type and size must be installed in your computer. Screen fonts are bitmapped fonts.
Slide 27:Lists : ordered or unordered, flat or multilevel. An ordered list would be used when whatever is being listed should be numbered while an unordered list may be used for a list of related items which could appear in any order. A normal list is flat, only one level, but it is possible to have a multilevel list (Outline Numbered List). Mammals Dogs Labrador Poodle Horses Dolphins
“is any amount of text, graphics, objects or other items that are followed by a paragraph mark” (¶) You insert a paragraph mark each time you press “Enter” Wrap around - word wrap
Slide 29:Widow and Orphan Control
Widow: the last line of a paragraph printed by itself at the top of a page Orphan: the first line of a paragraph printed by itself at the bottom of a page Keeping lines together
Allows more text to fit on a line Improves appearance Often used with full justification (e.g. newspaper columns) In Word can choose automatic or manual
Slide 31:Headers and Footers
Puts vital information on each page Can be text, drawing, page number, date, file name etc Need to use sections to have different headers and footers (as in assignment) Worth getting to know Logos First page
Master copy for all documents of a certain type Can include text and graphics Sets margins and document formats
Times New Roman 12 pt (in Word 2000) Left aligned Single spacing ….
Slide 34:Customised Templates
Saved as .dot files Easiest way to make a template: Open a document that has the formatting you want, and save it as a template Task for you
Slide 35:Hidden text
Hides notes and comments in a document Options Can be seen on screen (or not) Can be printed (or not) Warning - be careful how you use it!
Slide 36:Mail Merge
Mail Merge can be used to merge any kind of data with any other kind of document to individualise the documents. create a mail merge, need the data document and the merge document. The data document needs to be a tab-delimited or comma-delimited text file, which is simply a file with repeating fields that are separated ("delimited") by a tab character or a comma. Set up in MS Word, MS Access, MS Excel, or Outlook.
Slide 37:Bits (smallest unit of information) 1 bit = 0 or 1 Byte (8 bits) 1 byte: A single character Kilobyte (approximately 1000 bytes) 1 Kilobyte: A very short story 2 Kilobytes: A Typewritten page Megabyte (approximately 1 000 000 bytes) 1 Megabyte: A small novel 5 Megabytes: The complete works of Shakespeare 100 Megabytes: 1 metre of shelved books 650 Megabytes: A CD-ROM
Slide 38:Gigabyte (approximately 1 000 000 000 bytes) 1 Gigabyte: A pickup truck (eg. Ford F250) with cargo area filled with printed paper to a depth of 40 cm. 20 Gigabytes: A good collection of the works of Beethoven 100 Gigabytes: A floor of academic journals Terabyte (approximately 1 000 000 000 000 bytes) 1 Terabyte: 50, 000 trees made into paper and printed 10 Terabytes: The printed collection of the US Library of Congress Petabyte (approximately 1 000 000 000 000 000 bytes) 2 Petabytes: All US academic research libraries 200 Petabytes: All printed material Exabyte (approximately 1 000 000 000 000 000 000 bytes) 5 Exabytes: All words ever spoken by human beings. How many bits / bytes in a floppy disk / CD-ROM / in 10 GB? Conversion of binary to decimal
Slide 39:Representation standards
ASC II and Unicode Conversion of characters, numbers and symbols to binary numbers A = 100000001 B = 10000010 (1 byte) ASC II limited to 256 (28) different variations or characters A = 1000000000000001 (2 bytes) Unicode limit is 65000 different variations
Slide 40:Memory, CPU
RAM - random access memory volatile, temporary, fast access ROM - read only memory non-volatile, permanent, slow access, CACHE The processor is called the CPU central processing unit compatibility, speed, RISC (reduced instruction set computer) - IBM for Macs faster CISC (complex instruction set computer) - Intel for Pentiums slower Fetch instruction - Memory - Bus interface unit - pre fetch unit-decode unit- control unit- ALU arithmetic logic unit (registers of 32 and 64 bits)-sent back to memory Machine cycle: instruction set is read - write - move –operate on data- make decisions Algorithm that repeats forever: fetch instruction – increment program counter – decode instruction – obey instruction
Buses (travel between components of the computer in 8, 16, 32 bits) Ports (serial and parallel) Peripherals - input, output, storage (hard disk, floppy disk, tapes, zip, CD ROM, DVD) Moving data around - buses, ports, expansion slots, scsi drives Buying a computer - what will you do with it? Cost – software- expansion
Software: compilers software applications, system software Compilers and translators - translate programs to machine language Programming languages - C++ Java Basic How CPU executes a program (adding 2numbers): get (read) number at memory location x and place in register A, get another number, add contents of registers and put in register C, write (copy) register C to memory location y.
Integrated software: cheaper, transfer of data easier, feels and looks same Public domain software, shareware, freeware Proprietary software–licence(allowed to use the program,still property of the company) piracy
Slide 44:System Software
Taking care of hardware issues relating to what you are doing in software Operating systems: keeps hardware running efficiently, makes process of commun9icating with the hardware easier communicate with peripherals, coordinates concurrent processing of jobs (multitasking), manages the memory, data and program management, monitors resources, accounting and security, coordinates network communications. Multitasking is when the computer seems to be working on several programs at the same time (speed). Utility software: tools for doing system maintenance and some repairs the OS can’t automatically handle. Virus scan, fix corrupted data files
Slide 45:Operating System
MS-DOS, Macintosh, Microsoft Windows User Interface- software (application) program - operating system (hardware) Software compatibility (RTF) and reliability OS lives in ROM and starts up computer with “booting” process. Character based and Graphical User Interfaces (GUIs) – (advantages of GUIs) intuitive, consistent, forgiving, protective, flexible.
bandwidth - amount of information cable can hold (allow to travel on it) ISDN -integrated services digital network - callup digital line with 128Kbps T1 and T3 direct digital with 1.5-3Mbps Intranet – a small copy of internet at work inside the LAN/WAN network of a company. Extranet – a private network between company and business clients
Slide 47:Linking Up: Network Basics
Why is networking important? Cost allows people to share hardware Efficiency & Productivity allows people to share data and software Opportunity allows people to work together in ways that are otherwise difficult or impossible
Slide 48:LAN (Local Area Network)
Network of interconnected workstations Sharing common resources Within a relatively small geographic area
Slide 49:Client-Server LAN
Server Storehouse for software and data Management of shared resources Printers Client Computers that request server services
Slide 50:Peer-to-Peer LAN
There are no servers Shared resources managed by all computers Effective for small LANs
Slide 51:LAN Architecture
Almost all LANs are set up as one of Star Ring Bus
Every node is connected to the bus All communication travels along the bus Only one node can send information along the bus at a time Ethernet uses this model Node Node Node Node Node Bus
Slide 53:MAN, WAN
Networks that extend over a long distance MAN: Metropolitan Area Network WAN: Wide Area Network Usually composed of smaller MAN / LANs
Slide 54:WAN (Wide Area Network)
WANs are often made up of LANs
Slide 55:Differences between LANS and WANs
LANs small geographic area WANs large LANs almost always controlled by single organisation WANs usually aren’t LANs have a regular structure WANs don’t
Slide 56:The Network Interface
A Network Interface Card (NIC): Is needed to connect directly to a network Adds an additional port to the computer Controls the flow of data between the computer’s RAM and the network cable Converts the computer’s digital signals into the type required for the particular network
Modulator/demodulator Connects a computer to a telephone line Connection speed: Kbps
Slide 58:A modem is needed to connect a computer to a phone line
Communication á la Modem The computer communicates with digital signals The telephone system was designed to transmit voice signals, which are analogThe word modem comes from the terms modulation and demodulation
Slide 59:How a Modem Works
Slide 60:A modem: Converts the digital stream of information from a computer to an analog stream in order to send a message on the telephone network
Communication á la Modem
Slide 61:A modem: Converts the analog stream of information received over the telephone network into the digital form that the computer understands
Communication á la Modem
Slide 62:Building Bandwidth
The quality of information transmitted through a communication medium depends upon bandwidth. Increased bandwidth means faster transmission speed Bandwidth is affected by the amount of network traffic, software protocols, and type of network connection
An intranet is a private network that is contained within an enterprise Uses same technology as the Internet Typically connected to the internet by a firewall for security
Private Internet-like network designed for outside use (E-Commerce) An extranet can be viewed as part of a company's intranet that is extended to users outside the company
Slide 65:What is an algorithm?
Problem instance is an assignment of values to parameters Algorithm for a problem is a general step-by-step method taking any problem instance and giving a correct answer for the instance Algorithm is correct (for a problem) if it gives the correct answer for every instance of the given problem
Slide 66:Characteristics of Algorithms
Algorithm: sequence of steps to accomplish a task must produce output in all cases must terminate in all cases must produce correct results in all cases must be effective(each step is doable) must be definite (specific course of action for every eventuality)
Slide 67:Algorithms vs. Programs
Aren’t they the same thing? Computer can only perform tasks specified by simple operations it can execute We need to describe how the task can be completed; which operations to perform This description is known as an algorithm A program is an algorithm that can be directly executed by a computer
Slide 68:Selecting the Appropriate Chart
Bar and column charts emphasize variations between items over time use when data falls into a few categories Line chart show trends in data over time show relationship of one variable to another Pie chart show proportion of parts to a whole XY (scatter) chart used more often to discover relationships between data different chart types are better for displaying different sorts of data bar/col: E.g. Slide 24… show emphasize variations show few categories (don’t want lots of bars or lots of groups of bars - becomes hard to read) NOTE: stacked: shows how proportions of a whole change over time line charts: graphs of mathematical functions/statistical distributions different chart types are better for displaying different sorts of data bar/col: E.g. Slide 24… show emphasize variations show few categories (don’t want lots of bars or lots of groups of bars - becomes hard to read) NOTE: stacked: shows how proportions of a whole change over time line charts: graphs of mathematical functions/statistical distributions
Slide 69:Record Macro
to automate often repeated tasks Tools/Macro/Record New Macro Macro name box - name for macro Shortcut key Description box - what macro does Record Macro Click stop record button
Slide 70:Record Macro : Example
DEMO: Click on a cell, then Tools ? Macro ? Record Macro, Then select Format ? Cells ? Pattern ? Colour and select Red; hit OK. Then stop recording. Now this macros can be applied to other cells to highlight them.DEMO: Click on a cell, then Tools ? Macro ? Record Macro, Then select Format ? Cells ? Pattern ? Colour and select Red; hit OK. Then stop recording. Now this macros can be applied to other cells to highlight them.
Slide 71:Sort or filter macros
Highlight spreadsheet Data? sort: Data? filter? autofilter ? custom
Slide 72:Run a macro
Tools/macro/select name - as previous e.g. Shortcut key combination Assign macro to button/graphic & click
Slide 73:Adding Buttons
Forms toolbar/Button Tool Active cell - location of button Drag to desired size & shape Assign macro dialog displayed To display forms toolbar: right click on any toolbar - select forms can type any text in a button - can format font/alignment/orientation of button text - can assign existing macro or record a new macroTo display forms toolbar: right click on any toolbar - select forms can type any text in a button - can format font/alignment/orientation of button text - can assign existing macro or record a new macro
Slide 74:Representation in spreadsheets
Data consists of numbers or text Numeric data is real: dates, currency, percentages are stored as real numbers We said cell: data/formula - data: assumes data numeric unless it obviously is NOT (contains letters) - e.g. next slide... So 1 stored as 1.0 in Excel - this is significant!!! Real nos aren’t exact - more presently. What you see is NOT what Excel stores - The real nos are formatted to display currency, percentage & date A20 : typed in the no. 89993 - data: number (note right-justified) A21: typed in text data - data: text A22: typed in text 123this is text (first alpha. Char. -> text) - text left-justfified A23: typed in a no. preceded by ‘ --> treat this number as text. (Note: formula bar ) Why? some numeric-looking data isn’t - never to be used in a calculation e.g. student numbers ask yourself, will it ever be used in a calculation? If not, text - cannot then be inadvertently/mistakenly used in a formula (calculation) Dates: the 2 dates have the same real no. stored which represents 1/1/00 - different formatting -> different display characteristics Currency: similarly We said cell: data/formula - data: assumes data numeric unless it obviously is NOT (contains letters) - e.g. next slide... So 1 stored as 1.0 in Excel - this is significant!!! Real nos aren’t exact - more presently. What you see is NOT what Excel stores - The real nos are formatted to display currency, percentage & date A20 : typed in the no. 89993 - data: number (note right-justified) A21: typed in text data - data: text A22: typed in text 123this is text (first alpha. Char. -> text) - text left-justfified A23: typed in a no. preceded by ‘ --> treat this number as text. (Note: formula bar ) Why? some numeric-looking data isn’t - never to be used in a calculation e.g. student numbers ask yourself, will it ever be used in a calculation? If not, text - cannot then be inadvertently/mistakenly used in a formula (calculation) Dates: the 2 dates have the same real no. stored which represents 1/1/00 - different formatting -> different display characteristics Currency: similarly
Queries are used either to ask questions about the data in a database, or to specify those parts of a database for which data is to be changed in some way Choose the fields in a table that you wish to display Select on a certain set of the records in a table Show the selected material in some particular sequence Derive the data that is to be shown from a number of tables in the database Calculate totals
Access provides 2 ways to specify queries: QBE approach (Query By Example) - a graphical interface that allows you to design your query in a fairly intuitive manner. SQL (Structured Query Language) If you choose to use QBE to develop your query, you can have a look at the SQL view and see what SQL the query you design produces.
Slide 77:Three views for a query: Design view This lets you see the rules by which the query is constructed. It will show the table(s) used, the fields that have been selected, and any constraints (criteria) used to select particular records from the table(s). Datasheet view The datasheet view shows you the information that is produced when the query is run. SQL view This view shows the SQL query that is generated from the graphical specification
Slide 78:Types of queries
Select queries: The purpose of a select query is to extract and present information from the database. The way in which we specify what is to be selected and presented is by establishing criteria. Action queries: Action queries are used either to make new tables in a database, or to alter in some way the data (make table, delete,update,append).
Query by example, we select the fields that we wish to incorporate in the query by: First selecting the table(s) that we need to provide the required output Then selecting (in the order (left to right) that you wish the data to be presented) the fields you need.
Criteria are restrictions you place on a query to identify the specific records you wish to work with. Criteria: 2124 Use Null, And Or Not, Between Null is defined as nothing - an empty or zero length string. Is Not Null (has a value in the field) <> 0 (not equal to 0)
Slide 81:And / Or
And in QBE (>= 15 And <= 18) Field: WinbCommbWordbSsheetb Criteria:"O“ "E“ "E“ "E“ Or Tu2p Or Tu3p Criteria: Tu2p Or: Tu3p
Slide 82:Wild Cards
* (anything after or before *) Tu* (anything that starts with Tu). *p (anything that ends with p). ? - Matches any single alphabetic character (categori?e)  - Matches any single character within the brackets (c[au]t) ! - matches any character that is not specified in the square brackets b[!ae]ll finds bill and bull but not ball or bell - #
Slide 83:Wild Cards
- - Matches a range of characters. The range is in ascending order (A - Z). a[a-d]x will match aax, abx, acx, adx # - Matches a single numeric character 1#3 would match 103, 113, 123, 133, but not 1A3.
Sorting on one field Three options are available for the sequence in which any field appears: Ascending sequence Descending sequence Not sorted The field that you choose to sort over may be text, numeric or date
Slide 85:Show field option
The Show line on the QBE grid contains a Tick box for every field that is used in the query. When the box is crossed, the field is shown; if it is not, it is not visible when the query is viewed in datasheet view.
Slide 86:Saving queries
All query names start with Qry Update queries start with Qry Update Append queries start with Qry Append Name queries when you close the datasheet view of query
Slide 87:Multi-table queries
Much of the power of querying tables in a relational database is the ability to bring together data from multiple tables.
Graphics are represented by pixels (640x480, 800x600, 1024x768, 1280x960 screen sizes) Quality of graphics is determined by: Resolution of the screen (dpi) Number of colors Determined by hardware and software
Slide 89:Forms of Graphics
Bit mapped (raster graphics) Objects (vector graphics)
Slide 90:Black and White
Grey scale Represented as 1 byte per pixel 256 shades – more than naked eye can distinguish See demo at: http://www.aa6g.org/Astronomy /Articles/grayscale.html
Slide 92:Colour implementation
1 byte gives 256 colours 2 bytes gives 65536 colours Tradeoff between resolution and storage requirement
Dithering is the attempt by a computer program to approximate a colour from a mixture of other colours when the required colour is not available. For example, dithering occurs when a colour is specified for a Web page that a browser on a particular operating system can't support.
Slide 94:Browser Safe Palette
216-Color Browser-Safe Palette When specifying colors for Web page backgrounds, fonts, and other elements for 256-color displays (the most common display capability), you will probably want to choose from the 216 colors that look the same on both PC and Mac operating system
Graphics files are large The COMP123 logo is 472 x 81 pixels (38232 bytes) It is compressed to 23019 bytes Compression is the reduction in size of data in order to save space or transmission time.
Slide 96:Forms of compression
Lossless – e.g Winzip Lossy – e.g. jpeg
A JPEG (pronounced JAY-peg) is a graphic image created by choosing from a range of compression qualities (actually, from one of a suite of compression algorithm). When you create a JPEG or convert an image from another format to a JPEG, you are asked to specify the quality of image you want.
On the Web and elsewhere on the Internet, the GIF has become a de facto standard form of image. The LZW compression algorithm used in the GIF format is owned by Unisys replaced by PNG (which is free) GIF uses up more space.
Measured by sampling Uses lots of space Quality is a function of Sampling rate (Telephone line is 33KHz; ) Bit rate (Twice the bandwidth (Nyquist theory))
Combines pictures and sound Uses huge amounts of storage
Combination of text, numbers, graphics, sound, music, video, virtual reality and other media in hyperlinked documents
Bandwidth is directly proportional to the amount of data transmitted or received per unit time (measure of the range of frequencies the signal occupies)
Slide 103:Summary queries
Do not change the data in the database Produce total information View ?totals Created by using the ? tab Can combine the options
Slide 104:Action queries
An action query is a query that makes changes to many records in just one operation. Query?action queries There are four types of action queries: delete update append make-table
Slide 105:Delete query
Delete query Deletes a group of records from one or more tables.
Slide 106:Update queries
Example: Update the results for the Winb Basic assignment First – be quite clear about the rules.
Slide 107:Append query
Adds a group of records from one or more tables to the end of one or more tables Example: Add new students to Studdetails
Slide 108:Make Table
Creates a new table from all or part of the data in one or more tables Used for: Creating a history table that contains old records Creating a table to export to other Microsoft Access databases Taking a snapshot of a table
Slide 109:The expression we use:
Value:[UnitPrice] * [Quantity] What do the square brackets mean? Existing fields New price: [price]*1.1
Slide 110:SQL – Structured Query Language
Each query that you create produces an SQL version You can check this – there are three views of a query: Datasheet Design SQL
Slide 111:What is Electronic Commerce?
Electronic Commerce is the term used when commercial transactions take place across the Internet or another private network without human intervention
Slide 112:Business to Business Transactions
Most common form of E-Commerce Used in: Manufacturing Sales Allows for Just-In-Time manufacturing
Slide 113:EDI (Electronic Data Interchange)
EDI refers to the exchange of electronic business documents (no human intervention) EDI standards Agreement between 2 organisations
Slide 114:B2C Business to Customer
Growing area Some successes, lots of failures Must be built into the business model
Slide 115:Internet banking
Faster Cheaper More flexible Not time dependent
Slide 116:Web based retailing
Business to Customer The issues Is it working? Amazon has never made a profit for a whole year What sort of products sell?
Slide 117:Advertising, Marketing
The 4 Ps of Internet marketing Product Price Place (Distribution) Promotion
Slide 118:Security Issues
1. Confidentiality Privacy of message (encryption) 2. Integrity Detecting message tampering(Hashing) 3. Non-repudiation Provision of irrefutable evidence of origin, receipt and contents (Digital signatures etc)
Slide 119:Cont ..
4. Authentication Is the sender who he/she claims to be? (Digital signature, password etc) 5. Authorization Access control (limiting entry to authorized users) (Firewalls, passwords etc)
Slide 120:What is Cryptography?
Cryptography is a means of mathematical encoding that converts messages into a form that is unreadable, in an effort to maintain confidentiality of data.
Slide 121:Public key cryptography
There are two keys, public key, private key Public keys are published Private keys are kept secret (you keep your own private key)
Slide 122:Sending a message:A to B
Adam encrypts the message using Beth’s public key Beth decrypts the message using her private key
Anyone can send you a message Only you can decode it How does the recipient know who really sent the message?
Slide 124:What is a system?
A system is much more than the software that is used. System incorporates the software the training of users installation plan user documentation maintenance plan …….
Slide 125:Software Development Life Cycle
Requirements analysis Design Implementation Testing Installation Maintenance
Slide 126:Systems Development Life Cycle (1)
First catch your problem (the hardest bit it to get this right) Understand how the problem fits into the organisation’s overall scheme of things
Slide 127:Systems DLC (2)
Design a solution that fits into the organisation Develop the system as a whole Software Testing Training Systems documentation User documentation Installation plan Maintenance plan Plan for obsolescence
Slide 128:Systems DLC (3)
Systems Installation Systems maintenance (about 60-70% of the cost of a system is spent after the syetem is installed)
Slide 129:What is a VIRUS?
A virus is code inserted into a program cause some unexpected/undesirable result replicates itself
Slide 130:What should I do?
Install Anti-virus Software Use a legal copy - why? E-mail Downloads Floppies
Slide 131:How does Anti-Virus Software Work?
Signatures built in to the infected file The anti-virus trail Collect suspicious files Identify similar cases Work out what the virus does Develop antivenene Add to repertoire
Slide 132:Boot Sector Virus
Boot sector floppy disk hard disk Effect?
Slide 133:File Infector Virus
Attaches itself to program files .COM .EXE The effect?
Slide 134:Macro Virus
Typically Word or Excel Effect - often inserts rubbish Note the warning in Outlook!
Slide 135:Trojan Horse
Program that is expected to do one thing and does another Password capture
Self-contained program Spreads functional copies of itself Does not attach to a host program Two types Host worm Internet worm
Slide 137:What is Artificial Intelligence?
AI is the study of ideas which enable computers to do the things that make people seem intelligent (Winston). AI is the study of how to make computers do things which at the moment people are better at (Rich) AI is the study of the computations that make it possible to reason, perceive, and act (Winston).
Slide 138:How do you tell if a computer is intelligent?
Turing test (1950) A machine can be deemed intelligent when it can pass for a human being in a blind test. (computer, human) answer questions from human….depending on answers human must determine which answer came from a machine…if fooled then computer deemed intelligent. No computer has passed test.
Slide 139:Natural Language Processing
Speech recognition Language understanding Translation Language generation Text to speech synthesis Problem Syntax Semantics Syntactical ambiguity Semantic ambiguity Fluidity of language
Slide 140:Expert Systems
A software program designed to replicate the decision making process of a human expert. Examples Bank loans Credit card applications Medicine - diagnosis systems Design - Xerox paper handling systems Farming - CSIRO