Day 21 Web Searching The Vast Internet


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Day 21 Web Searching The Vast Internet

  1. 1. Day 21 Web Searching
  2. 2. The Vast Internet <ul><li>Billions of pages </li></ul><ul><li>Triples about every two years </li></ul>
  3. 3. How the web is indexed <ul><li>Search Engines </li></ul><ul><ul><li>Single-Threaded (Spider-based) </li></ul></ul><ul><ul><li>Multi-threaded (Meta) Search Engines </li></ul></ul><ul><li>Subject Indexes </li></ul>
  4. 4. Characteristics of All Web Indexes <ul><li>Limited Samples </li></ul><ul><ul><li>No central, all-inclusive index </li></ul></ul><ul><li>Snapshots </li></ul><ul><ul><li>never completely current </li></ul></ul><ul><li>All indexes miss some content </li></ul><ul><li>You need powerful search strategies </li></ul>
  5. 5. Varying Samples 150 275 Gigablast 125 733 NLResearch 500 1,015 Teoma 3,000 1,018 MSN Search 3,000 1,147 Hotbot 1,500 1,453 WiseNut 1,000 1,689 AltaVista 2,112 2,106 AlltheWeb 3,083 3,033 Google Claim (millions) Showdown Estimate (millions) Search Engine
  6. 6. Unique Results
  7. 7. Single-Thread Search Engines <ul><li>Powerful Searching Features </li></ul><ul><ul><li>+ (Match All Terms) </li></ul></ul><ul><ul><li>Match Any Term </li></ul></ul><ul><ul><li>- (exclusion) </li></ul></ul><ul><ul><li>“ Phrases” </li></ul></ul><ul><ul><li>Title Search </li></ul></ul><ul><ul><li>URL Search </li></ul></ul><ul><ul><li>Domain Search </li></ul></ul>
  8. 8. Multi-threaded (Meta) Search Engines <ul><li>Sample Multiple Other Databases in one interface </li></ul><ul><li>Broader sample than single-thread </li></ul><ul><ul><li>Can chose which other single-thread to sample. </li></ul></ul><ul><li>Less options for specific search control </li></ul><ul><ul><li>Can’t do URL, Title, and exclusion Searches </li></ul></ul>
  9. 9. Examples <ul><li>Metacrawler ( </li></ul><ul><li>Ixquick ( </li></ul><ul><li>SurfWax  ( </li></ul><ul><li>Dogpile ( </li></ul><ul><li>ProFusion ( </li></ul>
  10. 10. Subject Directories (general e.g., yahoo) <ul><li>Substantial Sites Organized in Categories (by humans) </li></ul><ul><li>Good for searching for general topics </li></ul><ul><li>Yahoo is largest on the Web </li></ul><ul><ul><li>over 1 million sites listed in their subject directory </li></ul></ul><ul><li>Looksmart is another subject directory used by MSN </li></ul>
  11. 11. Subject Directory / Crawler-Based Search Engine Combination <ul><li>It is becoming more popular to link subject directories with crawler-based search engines </li></ul><ul><li>These look first within subject directory and if that fails, they look within a crawler-based index: </li></ul><ul><ul><li>E.g.1, Yahoo’s extensive subject directory is seached. Yahoo then calls Google’s crawler based engine </li></ul></ul><ul><ul><li>E.g.2, MSN used the Looksmart subject directory then calls on Inktomi’s crawler based engine. </li></ul></ul>
  12. 12. Data Collection Highway
  13. 13. % of Web Users Using Specific Search Engines Each Month US Digital Media Universe Audience Reach Home & Work Users, January 2003
  14. 14. Day 22 Network Technology
  15. 15. Objectives <ul><li>Understand the fundamentals of data communications and the criteria for choosing a communications medium </li></ul><ul><li>Explain how networking media, devices, and software work together to provide data networking services </li></ul>
  16. 16. Fundamentals of Telecommunications <ul><li>Communications </li></ul><ul><ul><li>Transmission of a signal by way of a medium </li></ul></ul><ul><li>Signal </li></ul><ul><ul><li>Contains message comprised of data and information </li></ul></ul><ul><li>Communication medium </li></ul><ul><ul><li>Anything that carries a signal between a sender and a receiver </li></ul></ul>
  17. 17. Characteristics of Telecommunications <ul><li>Analog signal </li></ul><ul><ul><li>Continuously changes over time </li></ul></ul><ul><li>Digital signal </li></ul><ul><ul><li>At any given time is either high or low </li></ul></ul><ul><li>Signal frequency </li></ul><ul><ul><li>Speed at which signal can change from high to low </li></ul></ul>
  18. 20. Transmission Capacities <ul><li>Bandwidth </li></ul><ul><ul><li>Range of signal frequencies that can be sent over a given medium at the same time </li></ul></ul><ul><li>Broadband media </li></ul><ul><ul><li>Significantly faster than narrowband </li></ul></ul><ul><ul><li>Any media faster than 200 Kbps (kilobits per second) or 2 Mbps (megabits per second) </li></ul></ul><ul><li>Narrowband </li></ul><ul><ul><li>Anything below 200 Kbs </li></ul></ul>
  19. 22. Networking Media <ul><li>Twisted-pair cable </li></ul><ul><ul><li>Cable consisting of pairs of twisted wires </li></ul></ul><ul><li>Repeaters </li></ul><ul><ul><li>Used to boost signal so that it can travel longer distances </li></ul></ul><ul><li>Coaxial cable </li></ul><ul><ul><li>Inner conductor wire surrounded by insulation, a conductive shield, and a cover </li></ul></ul><ul><li>Fiber-optic cable </li></ul><ul><ul><li>Thousands of thin strands of glass or plastic bound together in a sheathing </li></ul></ul>
  20. 24. Networking Media (Continued) <ul><li>Microwave transmission </li></ul><ul><ul><li>High-frequency radio signal that is sent through the air </li></ul></ul><ul><li>Communications satellite </li></ul><ul><ul><li>A microwave station placed in outer space </li></ul></ul><ul><li>Global positioning system (GPS) </li></ul><ul><ul><li>Uses satellites to pinpoint the location of objects on earth </li></ul></ul>
  21. 27. Networking Media (Continued) <ul><li>Wireless fidelity (Wi-Fi) </li></ul><ul><ul><li>Wireless networking devices that use the 802.11 protocol </li></ul></ul><ul><ul><li>Uses wireless access points </li></ul></ul><ul><li>Bluetooth </li></ul><ul><ul><li>Enables digital devices to communicate wirelessly over short distances </li></ul></ul><ul><ul><li>Communicates at speeds of up to 1 Mbps within a range of up to 33 ft </li></ul></ul><ul><li>Infrared transmission </li></ul><ul><ul><li>Sending signals through the air via light wave </li></ul></ul>
  22. 29. Networking Devices <ul><li>Modems </li></ul><ul><ul><li>Modulates and demodulates signals </li></ul></ul><ul><ul><li>Cable modem </li></ul></ul><ul><ul><ul><li>Provides Internet access over a cable television network </li></ul></ul></ul><ul><ul><li>DSL modem </li></ul></ul><ul><ul><ul><li>Connects digital devices using a digital signal over telephone service (POTS) lines </li></ul></ul></ul><ul><li>Network adapter </li></ul><ul><ul><li>Computer circuit board, PC Card, or USB device </li></ul></ul>
  23. 30. Network Control Devices <ul><li>Hubs </li></ul><ul><ul><li>Used as a central point for connecting a series of computers </li></ul></ul><ul><li>Switches </li></ul><ul><ul><li>Fundamental part of most networks </li></ul></ul><ul><li>Repeaters </li></ul><ul><ul><li>Connect multiple network segments </li></ul></ul><ul><li>Bridges </li></ul><ul><ul><li>Connect two or more network segments </li></ul></ul>
  24. 31. Network Control Devices (Continued) <ul><li>Gateway </li></ul><ul><ul><li>A network point that acts as an entrance to another network </li></ul></ul><ul><li>Routers </li></ul><ul><ul><li>Can divide a single network into two logically separate networks </li></ul></ul><ul><li>Wireless access point </li></ul><ul><ul><li>Receives and transmits data to wireless adapters </li></ul></ul><ul><li>Firewall </li></ul><ul><ul><li>Device or software that filters the information coming onto a network </li></ul></ul>
  25. 32. Radio Frequency Identification (RFID) Devices <ul><li>Tiny microprocessor combined with an antenna </li></ul><ul><li>Tracks merchandise from supplier to retailer to customer </li></ul>
  26. 33. <ul><li>Note: there are a lot of good questions that can be reviewed on the posted lecture materials--Hollywood Squares </li></ul>
  27. 34. Day 23 LANs
  28. 35. How to create a LAN <ul><li>I. Connect the hardware together </li></ul><ul><li>II. Install software and “protocols” </li></ul><ul><li>III. Install “services” </li></ul><ul><li>IV. Set up files to share between computers </li></ul>
  29. 36. I. Hardware to connect <ul><li>Computers with NIC cards in them </li></ul><ul><ul><li>Now the NIC is often on the motherboard </li></ul></ul><ul><li>Cables </li></ul><ul><li>Hub or Switch </li></ul><ul><ul><li>What could the downside of using a hub be? </li></ul></ul><ul><ul><li>Which is faster a switch or a hub? </li></ul></ul><ul><ul><li>Which is more secure a switch or a hub? </li></ul></ul><ul><li>Router </li></ul><ul><ul><li>Usually your gateway to your ISP and the Internet </li></ul></ul>
  30. 37. II. INSTALL SOFTWARE & PROTOCOLS <ul><li>Suitable operating system software for networks such as </li></ul><ul><ul><li>Windows XP (workstation) </li></ul></ul><ul><ul><li>Server (Windows 2003 Server) </li></ul></ul><ul><ul><li>NOS (Windows 2003 Enterprise) Protocol is the common data communication language between computers. </li></ul></ul><ul><li>Protocol determines the following: </li></ul><ul><ul><li>the type of error checking to be used </li></ul></ul><ul><ul><li>data compression method, if any </li></ul></ul><ul><ul><li>how the sending device will indicate that it has finished sending a message </li></ul></ul><ul><ul><li>how the receiving device will indicate that it has received a message </li></ul></ul>
  31. 38. KEY PROTOCOLS <ul><li>NETBEUI </li></ul><ul><ul><li>NetBEUI stands for NetBIOS enhanced user interface. In turn, NetBIOS stands for network basic input/output system. This is an unroutable network protocol used by DOS, Microsoft Windows and OS/2-based systems to communicate with locally-attached file servers. </li></ul></ul><ul><ul><li>DOES NOT require special configuration </li></ul></ul><ul><li>TCP/IP </li></ul><ul><ul><li>TCP/IP is the primary Internet protocol </li></ul></ul><ul><ul><li>TCP is one of the main protocols in TCP/IP networks. Whereas the IP protocol deals only with digital data packets, TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent. </li></ul></ul><ul><ul><li>DOES require some configuration </li></ul></ul>
  32. 39. III. INSTALL SERVICES (FUNCTIONALITY) <ul><li>For example: file and print sharing, FTP, Web, etc. </li></ul>
  33. 40. IV. Set up what you want to share <ul><li>WORKGROUPS </li></ul><ul><li>RESOURCES TO SHARE </li></ul><ul><ul><li>SELECT A FOLDER </li></ul></ul><ul><li>ACCESS LEVEL (PERMISSIONS) </li></ul><ul><ul><li>FULL ACCESS </li></ul></ul><ul><ul><li>CHANGES </li></ul></ul><ul><ul><li>READ ONLY </li></ul></ul>
  34. 41. Networking Activities
  35. 42. #1 Crossover Cable The most simple connection <ul><ul><li>For transferring data from one machine to another when not on a LAN (perhaps an old hard drive to a new one) </li></ul></ul><ul><ul><li>Playing games without a hub (outside or in a car) </li></ul></ul>Note: “White w. Orange” means White with Orange Stripe More on cables
  36. 43. #1 Crossover Cable Instructions <ul><li>I. Hardware </li></ul><ul><ul><li>Plug crossover cable into NICs of both machines </li></ul></ul><ul><li>II. Software and Protocols (assuming XP) </li></ul><ul><ul><li>On each machine configure TCP/IP </li></ul></ul><ul><ul><ul><li>Start  Control Panel  Network Connections </li></ul></ul></ul><ul><ul><ul><ul><li>Or right click on “My Network Places” and select properties </li></ul></ul></ul></ul><ul><ul><ul><li>Right clink on “Local Area Connection” and select properties </li></ul></ul></ul><ul><ul><ul><li>Make sure your NIC card is showing </li></ul></ul></ul><ul><ul><ul><li>Select “Internet Protocol (TCP/IP)” or install if necessary </li></ul></ul></ul><ul><ul><ul><li>Click on Properties [Note: discuss briefly getting IP address automatically from a DHCP server] </li></ul></ul></ul><ul><ul><ul><li>Select “Use the following IP address” and type in the following </li></ul></ul></ul><ul><ul><ul><ul><li>IP Address: for one machine and for the other </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Subnet Mask: for both machines </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Click “OK” (gateway is not needed as we have no Internet connection) </li></ul></ul></ul></ul>
  37. 44. #1 Crossover Cable Instructions <ul><li>III. Services </li></ul><ul><ul><li>File and Printer Sharing for Microsoft Networks is installed by default on XP. </li></ul></ul><ul><ul><li>Get in the same workgroup </li></ul></ul><ul><ul><ul><li>Right-click on My Computer and select properties. Select the Computer Name tab. Left-click on the properties button. </li></ul></ul></ul><ul><ul><ul><li>Make sure the workgroup names are identical. Use Change button toward the bottom of the current window if necessary. </li></ul></ul></ul>
  38. 45. <ul><li>IV. Files to share </li></ul><ul><ul><li>Right-click on a folder you wish to share. Then left-click on the Sharing and Security selection. </li></ul></ul><ul><ul><li>Check the “Share this file on the network” box. </li></ul></ul><ul><ul><li>Click the Apply button and then the OK button when you have finished the information. A hand should appear under the file or folder indicating that it has share-level access. </li></ul></ul><ul><li>Go to “My Network Places” and enjoy your workgroup resources! </li></ul>#1 Crossover Cable Instructions
  39. 46. #2 Hub or Switch <ul><li>Exactly the same as #1, except regular straight-through cables are plugged between the NIC cards and the hub or switch. </li></ul>
  40. 47. Networks for Your Home <ul><li>Wired option – install a router and CAT5 Twisted-pair cable through your house </li></ul><ul><li>“No-New-Wires” for a home network </li></ul><ul><ul><li>Wireless (Wi-Fi) – Wireless router and PC Cards </li></ul></ul><ul><ul><ul><li>Set secure login and encrypt transmissions! </li></ul></ul></ul><ul><ul><li>HomePlug – House AC electrical wires </li></ul></ul><ul><ul><li>HomePNA – House phone wires </li></ul></ul>
  41. 48. Networks for Your Home $150-$180 $80-$130 $135-$150 Router/ Access Point $55-$60 $150-$180 $70-$145 USB Adapter $50-$60 n/a $70-$110 PC Card 10 14 11 Speed (mbps) HomePNA HomePlug Wi-Fi
  42. 49. #3 Add a HomePlug Connection <ul><ul><li>Plug HomePlug adapter into electrical outlets. </li></ul></ul><ul><ul><ul><li>no power box or strip can be in between </li></ul></ul></ul><ul><ul><li>Plug straight through cables into adapter box. </li></ul></ul><ul><ul><li>Watch for blinking lights indicating there is a connection. </li></ul></ul>
  43. 50. Wireless Networks <ul><li>Range 100 – 500 ft. </li></ul><ul><ul><li>Can be limited by walls, metal, people </li></ul></ul><ul><li>Throughput 1 – 11 Mbps. </li></ul><ul><li>Benefits </li></ul><ul><ul><li>User mobility </li></ul></ul><ul><ul><li>Installation speed & flexibility </li></ul></ul><ul><ul><li>Scalability </li></ul></ul>
  44. 51. Your Gateway <ul><li>The gateway connecting your home LAN to the Internet is normally done through a </li></ul><ul><ul><li>dial-up modem </li></ul></ul><ul><ul><li>DSL router/modem </li></ul></ul><ul><ul><li>Cable router/modem </li></ul></ul>
  45. 52. #4 Remote Desktop <ul><li>Remote desktop allows you to work on a computer and view the screen as though you are sitting right there even though you may be half a world away (like China)! </li></ul>
  46. 53. #4 Remote Desktop <ul><li>Set your computer to allow remote access. </li></ul><ul><ul><li>Right click on “My Computer” and select properties </li></ul></ul><ul><ul><li>Click on the “Remote” tab and check “Allow others to connect remotely to this computer” </li></ul></ul><ul><ul><li>Note: you must have an administrator account unless you specifically “Select Remote Users” </li></ul></ul><ul><ul><li>Click “OK” </li></ul></ul><ul><ul><li>Note: You must have a static IP address or know what the current IP address is for this machine </li></ul></ul><ul><li>Connect remotely to the machine </li></ul><ul><ul><li>Start  All Programs  Accessories  Communications  Remote Desktop Connection </li></ul></ul>
  47. 54. #4 Remote Desktop <ul><li>You may also </li></ul><ul><ul><li>Print remotely or to your local printer </li></ul></ul><ul><ul><li>Copy and past files between your remote desktop and your local machine </li></ul></ul><ul><li>Directions: when connecting click “Options>>” </li></ul><ul><ul><li>On the “Local “Resources” tab check “disk drives” and “printers” </li></ul></ul><ul><ul><li>Then “Connect” </li></ul></ul>
  48. 55. #5 Testing Connectivity <ul><li>Ping </li></ul><ul><li>Tracert (trace route) </li></ul><ul><li>IPCONFIG (to get your IP address) </li></ul>Demo with Internet connection
  49. 56. #7 Visual Traces <ul><li>Visually trace </li></ul><ul><ul><li>How many hops to favorite URLs </li></ul></ul><ul><ul><li>Where fraudulant junkmail is coming from and report it </li></ul></ul><ul><ul><li>Who owns a particular IP address </li></ul></ul><ul><li>Some free trial products include </li></ul><ul><ul><li>VisualRoute </li></ul></ul><ul><ul><li>Visual WhoIs </li></ul></ul><ul><ul><li>Aet_Tracer </li></ul></ul>
  50. 57. #8 Voice over IP <ul><li>Talk to family and friends across the country or across the world free . </li></ul><ul><ul><li>They must also have a computer running the same VoIP program </li></ul></ul><ul><li>Possible free software includes Skype </li></ul><ul><ul><li>Download it at http:// </li></ul></ul>
  51. 58. Day 24 Web Commerce
  52. 59. Objectives <ul><li>Define e-commerce and understand its role as a transaction processing system </li></ul><ul><li>Define the three types of e-commerce and mobile commerce, listing the benefits and challenges associated with each </li></ul><ul><li>Discuss several examples of how e-commerce and mobile commerce are being used to provide services </li></ul><ul><li>List the components of an e-commerce system and explain how they function together to provide e-commerce services </li></ul>
  53. 60. Types of E-commerce <ul><li>Business-to-consumer e-commerce (B2C) </li></ul><ul><ul><li>Connects individual consumers with sellers </li></ul></ul><ul><li>Business-to-business e-commerce (B2B) </li></ul><ul><ul><li>Supports business transactions across private networks, the Internet, and the Web </li></ul></ul><ul><li>Consumer-to-consumer e-commerce (C2C) </li></ul><ul><ul><li>Connects individual sellers with people shopping for used items </li></ul></ul>
  54. 62. M-commerce Technology <ul><li>Mobile commerce (m-commerce) </li></ul><ul><ul><li>E-commerce that takes place over wireless mobile devices </li></ul></ul><ul><li>Technologies and standards </li></ul><ul><ul><li>Wireless Application Protocol (WAP) </li></ul></ul><ul><ul><li>Wireless Markup Language (WML) </li></ul></ul><ul><ul><li>Bluetooth </li></ul></ul>
  55. 63. Benefits and Challenges of E-commerce <ul><li>Buyers enjoy the convenience of shopping from their desktop </li></ul><ul><li>B2C e-commerce </li></ul><ul><ul><li>Levels the playing field between large and small businesses </li></ul></ul><ul><li>Challenges </li></ul><ul><ul><li>Established businesses must alter systems and business practices </li></ul></ul><ul><ul><li>Social concerns </li></ul></ul>
  56. 64. E-Commerce Applications <ul><li>E-tailing provides customers with </li></ul><ul><ul><li>Product information </li></ul></ul><ul><ul><li>The ability to comparison shop </li></ul></ul><ul><li>E-tailing options </li></ul><ul><ul><li>Set up an electronic storefront </li></ul></ul><ul><ul><li>Lease space in a cybermall </li></ul></ul>
  57. 65. Online Clearing Houses, Web Auctions, and Marketplaces <ul><li>Provide a platform for businesses and individuals to sell their products and belongings </li></ul><ul><li>Online clearinghouses </li></ul><ul><ul><li>Manufacturers can liquidate stock </li></ul></ul><ul><ul><li>Consumers can find a good deal </li></ul></ul>
  58. 66. Online Clearing Houses, Web Auctions, and Marketplaces (Continued) <ul><li>Most popular auction/marketplace </li></ul><ul><ul><li> </li></ul></ul><ul><li>Auction houses </li></ul><ul><ul><li>Do not accept liability for problems that buyers or sellers may experience </li></ul></ul>
  59. 67. E-Commerce Implementation <ul><li>Implementing e-commerce </li></ul><ul><ul><li>Requires expertise </li></ul></ul><ul><ul><li>May require large investment </li></ul></ul><ul><li>E-commerce host </li></ul><ul><ul><li>Business that takes responsibility for setting up and maintaining an e-commerce system </li></ul></ul>
  60. 69. Infrastructure <ul><li>E-commerce </li></ul><ul><ul><li>Requires significant infrastructure changes </li></ul></ul><ul><li>Changes may be required in </li></ul><ul><ul><li>Personnel, manufacturing processes, storage, shipping, information systems, etc. </li></ul></ul><ul><li>Organizations expanding to the Web </li></ul><ul><ul><li>All areas of business are affected </li></ul></ul><ul><ul><ul><li>Manufacturing, finance, sales, customer service </li></ul></ul></ul>
  61. 70. Software <ul><li>Web Server Software </li></ul><ul><ul><li>Responds to requests for Web pages </li></ul></ul><ul><li>Web Server Utility Programs </li></ul><ul><ul><li>Provide statistical information about server usage and Web site traffic patterns (i.e. Omniture) </li></ul></ul><ul><li>E-commerce Software </li></ul><ul><ul><li>Supports e-commerce activities </li></ul></ul><ul><ul><li>Includes catalog management, electronic shopping cart, and payment software </li></ul></ul>
  62. 72. Building Traffic <ul><li>The 3Cs Approach </li></ul><ul><ul><li>Content, community, and commerce </li></ul></ul><ul><li>Keywords and Search Engines </li></ul><ul><ul><li>Choose name and product names that best describe business purpose and features </li></ul></ul><ul><ul><li>Select descriptive domain names </li></ul></ul><ul><ul><li>Business-related keywords can be listed in the HTML meta tag </li></ul></ul>
  63. 73. Building Traffic (Continued) <ul><li>Partnerships </li></ul><ul><ul><li>Online e-tailers often form partnerships and advertise each other’s Web sites </li></ul></ul><ul><li>Marketing </li></ul><ul><ul><li>Online advertising methods include banner ads, pop-up ads, and e-mail </li></ul></ul><ul><ul><li>Offline advertising methods include magazines, newspapers, radio, and television </li></ul></ul>
  64. 74. Electronic Payment Systems <ul><li>Electronic cash (e-cash or digital cash) </li></ul><ul><ul><li>Provides a private and secure method of transferring funds </li></ul></ul><ul><ul><li>PayPal </li></ul></ul><ul><ul><ul><li>Best-known e-cash provider </li></ul></ul></ul><ul><li>E-cash benefits </li></ul><ul><ul><li>Privacy - hides account information from vendors </li></ul></ul><ul><ul><li>Convenient if seller cannot process a credit card </li></ul></ul>
  65. 75. Electronic Payment Systems (Continued) <ul><li>Electronic wallet, or e-wallet </li></ul><ul><ul><li>Encrypts and stores credit-card information, e-cash information, etc., securely on your computer </li></ul></ul><ul><li>Smartcards </li></ul><ul><ul><li>Credit cards with embedded microchips </li></ul></ul>
  66. 76. E-commerce Security Issues <ul><li>Digital certificate </li></ul><ul><ul><li>A type of electronic business card </li></ul></ul><ul><ul><li>Attached to Internet transaction data </li></ul></ul><ul><ul><li>Verifies the sender of the data </li></ul></ul><ul><ul><li>Provided by certification authorities </li></ul></ul><ul><ul><li>Encryption </li></ul></ul><ul><ul><ul><li>Uses high-level mathematical functions and computer algorithms to encode data </li></ul></ul></ul>
  67. 77. E-commerce Security Issues (Continued) <ul><li>Digital certificates combined with Secure Sockets Layer (SSL) technology </li></ul><ul><ul><li>Allow for encrypted communications to occur </li></ul></ul><ul><li>Spoofing </li></ul><ul><ul><li>Used to impersonate others on the Internet </li></ul></ul>
  68. 78. E-commerce Security Issues (Continued) <ul><li>Denial of Service Attacks </li></ul><ul><ul><li>Use many computers to request Web pages from the same Web server, at the same time </li></ul></ul><ul><ul><li>Zombie computers </li></ul></ul><ul><ul><ul><li>Computers that are either hacked into or under the influence of a virus or worm </li></ul></ul></ul>
  69. 79. Business Resumption Planning <ul><li>Takes into account </li></ul><ul><ul><li>Every conceivable disaster that could negatively impact the system </li></ul></ul><ul><li>Goal </li></ul><ul><ul><li>To protect data and keep key systems operational until order is resumed </li></ul></ul>
  70. 80. What’s New in E-Commerce? <ul><li>Phishing Threatens the Future of E-commerce </li></ul><ul><ul><li>Phishing scams involve hackers that use e-mail and Web sites to impersonate an authentic business in an effort to get unsuspecting customers to type in personal and private information. </li></ul></ul>
  71. 81. Summary <ul><li>E-commerce </li></ul><ul><ul><li>Systems that support electronically executed transactions </li></ul></ul><ul><li>Transaction processing system (TPS) </li></ul><ul><ul><li>Supports and records transactions </li></ul></ul><ul><li>Three main types of e-commerce </li></ul><ul><ul><li>Business-to-consumer (B2C) </li></ul></ul><ul><ul><li>Business-to-business (B2B) </li></ul></ul><ul><ul><li>Consumer-to-consumer (C2C) </li></ul></ul><ul><li>Mobile commerce, or m-commerce </li></ul><ul><ul><li>Takes place over wireless mobile devices </li></ul></ul>
  72. 82. Summary (Continued) <ul><li>Retail Web sites </li></ul><ul><ul><li>Allow consumers to comparison shop </li></ul></ul><ul><li>E-commerce </li></ul><ul><ul><li>Makes market research easier and less intrusive </li></ul></ul><ul><ul><li>Requires investment in networking, hardware, and a wide variety of software </li></ul></ul><ul><ul><li>Requires changes in infrastructure </li></ul></ul><ul><li>Hardware and networking services for e-commerce </li></ul><ul><ul><li>Must be robust and trustworthy </li></ul></ul>
  73. 83. Day 25 Flowcharting
  74. 84. Why Do Flowcharting? <ul><li>Economically expresses process logic “A picture is worth a thousand words.” </li></ul><ul><li>Independent of implementation </li></ul><ul><ul><li>Physical or logical processes </li></ul></ul><ul><ul><li>Supports any programming environment </li></ul></ul><ul><li>Works well for technical and non-technical people. </li></ul>
  75. 85. Where does Flowcharting Fit in Systems Development? <ul><li>During Analysis to document current process logic. </li></ul><ul><li>During Design to communicate specified process logic to the implementation/construction staff. </li></ul><ul><li>During Implementation to document procedures and processes. </li></ul>
  76. 86. Consider Some Examples
  77. 87. Problem 1 <ul><li>Dave Smarsh wants to find out how much money he will have in his savings account after a certain number of years (the balance). </li></ul><ul><li>He knows: </li></ul><ul><ul><li>The amount he will deposit </li></ul></ul><ul><ul><li>the interest rate he will receive </li></ul></ul><ul><ul><li>the number of years he will be save his money </li></ul></ul><ul><ul><li>Assumption: interest is compounding </li></ul></ul><ul><li>Develop a flowchart to calculate and print the balance in a savings account. </li></ul>
  78. 88. Think Like A Computer: Outline the Process <ul><li>First: </li></ul><ul><ul><li>Input the Data </li></ul></ul><ul><li>Second: </li></ul><ul><ul><li>Perform the Algorithm </li></ul></ul><ul><ul><li>(Logic and Calculations) </li></ul></ul><ul><li>Third: </li></ul><ul><ul><li>Output the Results </li></ul></ul>
  79. 89. Understand the “Algorithm” (Logic and Calculations) <ul><li>After one year the balance is: </li></ul><ul><ul><li>Balance = Deposit * (1 + Rate/100) </li></ul></ul><ul><li>After the second year: </li></ul><ul><ul><li>New Balance = Old Balance * (1+Rate/100) </li></ul></ul><ul><ul><li>New Balance = Deposit * (1+Rate/100)^2 </li></ul></ul><ul><li>After year n: </li></ul><ul><ul><li>Balance = Deposit * (1 + Rate/100) ^ n </li></ul></ul>
  80. 90. Order (Precedence) of Math Operations <ul><li>Programs use algebra rules </li></ul><ul><li>Avoids unnecessary characters in formulas </li></ul><ul><li>Complex formulas can be on one line </li></ul>Z = (20*12)^3/15
  81. 91. Order Operations <ul><li>Do Everything within parentheses first. </li></ul><ul><li>“ Inner” parentheses takes precedence over outer parentheses </li></ul><ul><li>The power operator (^) takes precedence over multiply (*) & divide (/). </li></ul><ul><li>Multiply (*) & divide (/) take precedence over addition (+) and subtraction (-). </li></ul><ul><li>Consider the formula: </li></ul><ul><ul><li>Balance = Deposit * (1 + Rate/100) ^ n </li></ul></ul>
  82. 92. Flowchart Symbols <ul><li>Start/End </li></ul><ul><li>Input/Output </li></ul><ul><li>Process/Computation </li></ul><ul><li>Decision </li></ul><ul><li>Connector </li></ul><ul><li>Logic Flow </li></ul>
  83. 93. Problem 1 <ul><li>Dave Smarsh wants find out how much money he will have in his savings account after a certain number of years (the balance). He knows how much he is going to deposit, the interest rate that he will receive, and the number of years that he will be saving his money. (Assume that the interest is compounding). </li></ul><ul><li>Develop a flowchart to calculate and print the balance in a savings account. </li></ul>
  84. 94. START INPUT Deposit, Rate, No.Years PRINT Deposit, Rate, No.Years, Balance BALANCE = Deposit * (1 + Rate/100) ^ No.Years #1 Solution FINISH This Program Control Structure is called: “ SEQUENTIAL”
  85. 95. Problem 2 <ul><li>Captain Beefnut, the proud owner of Beefnut Doughnut Shop, needs a program that will calculate and print bills for his customers. </li></ul><ul><li>His usual price for doughnuts is 60 cents each, but in order to increase sales he has reduced the price to 40 cents each if a customer buys 12 or more. </li></ul><ul><li>Develop this in a flowchart form. </li></ul>
  86. 96. #2 Solution This Program Control Structure is called: “ SELECTION or Decision”
  87. 97. Consider an Extension <ul><li>Suppose Captain Beefnut wanted his program to repeat the algorithm if there was another customer bill to calculate. Add a loop which will accomplish this change. </li></ul>
  88. 98. #2 with loop This Program Control Structure is called: “ LOOPING” or “ ITERATION” or “ REPETITION”
  89. 99. Day 26 Programming