Exploring Social Networks in Computer Systems

Report ID: TR-779-07
Author: Shao, Yilei
Date: 2007-05-00
Pages: 119
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Abstract:

Since the first appearance of computers half a century ago, computing technology continues to evolve rapidly. Having the most powerful and fastest computers is no longer the only goal for a successful computer system. A common characteristic of successful computer systems in the modern era is the ability to utilize vast amounts of information efficiently.

We introduce two important concepts from sociology into computer science: human capital and social capital. In a society, people who possess high human capital are individuals with more ability. They are more intelligent, more attractive, more articulate, and more skilled. In the human capital metaphor, these people are more likely to do better than others. Social capital is the contextual complement to human capital. In the social capital metaphor, people who do better are somehow better connected. The asset they possess is the advantageous location in the society. Today's computer systems exhibit a strong resemblance to human society. The linkage relationships among nodes in a system affect the performance of the system to a large extent. A well-connected system can outperform a collection of powerful nodes.

In this dissertation, we present results of applying the social capital metaphor to two kinds of computer systems: focused web crawling and peer-to-peer systems. We have designed and implemented a novel focused crawler that captures the topical linkage in the web. We have introduced the notion of "topical link". Topical links connect pages with similar content. By combining topical links with hyperlinks, the connectivity of the web graph is greatly enhanced. In our study of peer-to-peer systems, we have introduced the concept of "buddy net". Buddy net connects peers with similar interests in the peer-to-peer systems. It is an interest-based overlay on top of the physical overlay in peer-to-peer systems. With the help of buddy net, the efficiency and robustness of a peer-to-peer system is greatly improved.