Courses/Computer Science/CPSC 203/CPSC 203 2007Fall L04/CPSC 203 2007Fall L04 Lectures/Lecture 2
Contents
Lecture 2
The objectives of this class were to:
- Quickly set some class etiquette standards, determine final topics list
- Describe the Origins of the Internet, it's structure, and how that structure is evolving. Link Internet structure to its capabilities and limitations
Lecture Glossary
- Hub - A node with many edges. In terms of web pages, a hub is considered a web page that is linked to by many other web pages.
- TCP/IP - Transfer Control Protocol/Internet Protocol
- HTTP - Hyper Text Transfer Protocol
- WWW - World Wide Web
- HTML - Hyper Text Mark-up Language
- XML - File type: eXtensible Markup Language
- Web 1 - A general reference to the World Wide Web during its first few years of operation. The term is mostly used to contrast the earlier days of the Web before blogs, wikis, social networking sites and Web-based applications became commonplace.
- Web 2 - An umbrella term for the second wave of the World Wide Web, which was coined by O'Reilly Media (www.oreilly.com) and CMP Media (www.cmp.com) in their 2004 and subsequent conferences on the subject. Sometimes called the "New Internet," Web 2.0 is not a specific technology; rather, it refers to two major paradigm shifts. The one most often touted is "user-generated content," which relates more to individuals. The second, which is equally significant, but more related to business, is "thin client computing."
- Scale-Free Network - A scale-free network is a noteworthy kind of complex network because many "real-world networks" fall into this category. In a scale-free network there are many very connected nodes and hubs of connectivity that shape the way it operates. It is resistant to random attacks but direct attacks on the hubs are more volatile and can lead to failure.
- Email - A system for sending and receiving messages electronically over a computer network, as between personal computers.
Only Connect : Origins and Structure of the Internet
Only connect! That was the whole of her sermon.
Only connect the prose and the passion, and both will be exalted,
And human love will be seen at its height.
Livfe in fragments no longer.
Only connect ...
-- E.M. Forster, Howards End.
Key Take home concepts:
- Cartoon history of the Internet (Arpnet(TCP/IP) -- Internet --- Web 1.0(HTTP and HTML) ---- Web 2.0 (XMLs)
- The notion of a scale free network
- How a scale free network develops (growth, and preferential attachement of new nodes to existing nodes with higher connectedness)
- Properties of scale free networks as they relate to the Internet (resistant to random attacks, theoretically vulnerable to directed attacks on hubs, in a scale free network there is no minimum threshold for viral contagion).
To be scale-free
Dynamics
- Growth
- Preferential Attachment
Properties
- "Small Worlds" Phenomena
- Resistant to Random Attacks
- Susceptible to Directed Attacks on Hubs (theoretically)
- No minimal viral threshold -- viruses can 'hang around' and reinfect population
Lecture Resources
See http://en.wikipedia.org/wiki/Scale-free_network
and particularly the wonderful Scientific American Article: http://www.nd.edu/~networks/Publication%20Categories/01%20Review%20Articles/ScaleFree_Scientific%20Ameri%20288,%2060-69%20(2003).pdf
One of the "pioneers" in exploring the Internet as if it were an ecosystem is Bernardo Huberman. Here is a link to his book, "The Laws of the Web" and other research: http://www.hpl.hp.com/research/idl/people/huberman/
E.M. Forster poem fragment from: http://web.mit.edu/gtmarx/www/connect.html
The Laws of the Web. Patterns in the Ecology of Information. 2001. By B.A. Huberman.
Linked. How Everything is Connected To Everythiung Esle and What it Means for Business, Science, and Everyday Life. 2003. By AL Barabasi.
Weaving the Web. The Original Design and Ultimate Desitny of the World Wide Web by its Inventor. 1999. Tim Berners-Lee.
