Courses/Computer Science/CPSC 203/CPSC 203 2007Fall L04/CPSC 203 2007Fall L04 Lectures/Lecture 21

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Lecture 21

We are pleased to have today two student guest mini-lectures:

  • Internet Gaming
  • Network Security

We'll wrap up today with a retrospective overview of some of the themes of this course, in a "connecting the dots" session. On our last class (December 7th) I will take you through a study guide for the final.

The objectives of today's class are:

  • House Keeping
      • Group Project Presentations begin the week of Nov 26th. Will be by lab/tutorial sections. Tuesday's Groups Are (see Schedule). Group Projects websites will be marked based on version TA's download Dec 7th.
      • Assignment 2 due by midnight Nov. 23rd. TA's will focus on this for this week's tutorials.

    • Reminders:
      • Final Exam Date and Time has been set: Monday Dec 17, 12-2p.m at KN RED GYM. Remember to bring your student ids.

  • Topics
    • 2 Student mini-lectures
    • Quick Review of Page Rank Algorithm
    • Quick Review of Final format (app. 40 Q, 20% pre-midterm; 80 % post mid-term. Questions from guest lectures and Group Projects; I'll hand out and go over a study guide on our last class -- Dec 7th).
    • The Page Rank Algorithm
    • Connecting the Dots.

Page Rank

As a formula: PR(u) = SUM (PR(v)/L(v))

In English: The Page Rank (PR) of a page, "u" is based on summing all the Page Ranks divided by the No. of Links (L) from each page "v". Where for a given Page "u", "v" are all the pages that link into it.

The reason the Page Rank of a page v, PR(v) is divided by the number of links from that page, L(v) acts as a vote for the page u. So, if a page v, has only one link, it's page rank is totally assigned to u. Otherwise, it's page rank is 'pro-rated' by the number of links it has to other pages.

Technical Difficulty: This algorithm is actually recursive. So, to find the Page Ranks for "v", you have to apply the algorithm to the pages that link into v, and so on, and so on. This is called a "Recursive Algorithm".

  • illustrative example using Dots-and-Edges graph.

For more technical details go to:

Course Themes

Information in the Large (Concepts independant of specific technologies)

  • Networks as Ecosystems
  • Set Theory/ Logic in Pictures (including circuits)
  • Models/ Dots and Edges approach
  • Basic Stats/Probability Concepts/ Data Analysis and Graphic Design (The world according to Tufte)
  • Idea of a Computer (Turing Machines)
  • .... Conceptual tools to help you solve problems in any field of endeavour (from accounting to strategy, to experimental design, to graphic design)

Information in the Small (Skills, Techniques, Design Ideas often tied to specific technologies)

  • How to organize and analyze data ....
    • using a spreadsheet
    • using a database (particularly database queries)
    • using charts
  • Basic parts of a computer and OS
  • Some Basic ideas in computer security (attack trees can be seen as part of problem-solving above).

Connecting the Dots (technologies evolve, concepts re-appear, and technologies meet sociologies)

  • The Internet is growing and evolving (and has evolved far beyond its original design)
  • While technology changes rapidly, certain ideas keep re-appearing
    • for example, "How is a Search Engine like a Data Base
    • the basic design of the computer is still a Von-Neumann machine
    • programming is still applied problem solving ...
  • As internet technology becomes pervasive, it intersects with social issues
    • virtual world vs real world
    • control: economics, privacy, freedom
  • As individual technologies develop, and the internet continues to grow
    • new capabilities are created for products, social activities, games, etc. and
    • new challenges occur around control.
  • No one individual or organization is designing the future of technology, rather we are all enmeshed in it

I look forward to learning from you all during the next 2 weeks of group project presentations!