http://nsdl.library.cornell.edu/websites/expertvoices/info2040/archives/1795 This is a supplemental blog for a course which will cover how the social, technological, and natural worlds are connected, and how the study of networks sheds light on these connections. Fri, 08 Mar 2013 14:24:09 +0000 http://wordpress.org/?v=2.3.3 http://nsdl.library.cornell.edu/websites/expertvoices/info2040/archives/1795#comment-1221 Cornell Info 204 - Networks » Blog Archive » Interplay between Network Structure and Evolutionary Game Theory Mon, 30 Apr 2007 02:14:19 +0000 http://nsdl.library.cornell.edu/websites/expertvoices/info2040/archives/1795#comment-1221 [...] Previous studies found that the role of spatially structured populations (much like the ones we have been studying in class) on the emergence of cooperation varied from game to game. In contrast, this study actually found that when networks were grown using Barabasi’s preferential attachment model (described previously and in class) cooperation becomes a predominant trait for both games on both large and small networks at equilibrium independent of how the relative payoffs are set. The explanation proposed that hubs within the network are havens for cooperators. As the hubs are highly interconnected, they resist invasion by lone defectors. They found that if they removed the age-correlations that Barabasi’s model encourages then cooperation is less prevalent. [...] […] Previous studies found that the role of spatially structured populations (much like the ones we have been studying in class) on the emergence of cooperation varied from game to game. In contrast, this study actually found that when networks were grown using Barabasi’s preferential attachment model (described previously and in class) cooperation becomes a predominant trait for both games on both large and small networks at equilibrium independent of how the relative payoffs are set. The explanation proposed that hubs within the network are havens for cooperators. As the hubs are highly interconnected, they resist invasion by lone defectors. They found that if they removed the age-correlations that Barabasi’s model encourages then cooperation is less prevalent. […]

]]> http://nsdl.library.cornell.edu/websites/expertvoices/info2040/archives/1795#comment-1220 Cornell Info 204 Digest » Blog Archive » Combinatorial auctions, fairness in games and growth in networks Thu, 01 Mar 2007 20:32:59 +0000 http://nsdl.library.cornell.edu/websites/expertvoices/info2040/archives/1795#comment-1220 [...] Fifo writes about combinatorial auctions in which the sellers has many objects to sell and the buyers are interested in buying packages of objects. The idea is that a buyer’s value for one object depends on whether or not he wins another object and this makes the problem is much more complex than the auctions we have talked about in class. Interestingly, with a bit of generalization, Vickery’s results on second-price auctions also solve a simple version of this problem with independent values. If bidders bid on all packages of objects then in a second-price-like auction, truthful bidding is a dominant strategy. Many issues remain because this auction may be too complex to actually run, values may not be simple and they may not be easy access. The extension of the Vickery auction that solves the problem is called a Vickery-Clarke-Groves mechanism. We will discuss this mechanism later in the course. [...] […] Fifo writes about combinatorial auctions in which the sellers has many objects to sell and the buyers are interested in buying packages of objects. The idea is that a buyer’s value for one object depends on whether or not he wins another object and this makes the problem is much more complex than the auctions we have talked about in class. Interestingly, with a bit of generalization, Vickery’s results on second-price auctions also solve a simple version of this problem with independent values. If bidders bid on all packages of objects then in a second-price-like auction, truthful bidding is a dominant strategy. Many issues remain because this auction may be too complex to actually run, values may not be simple and they may not be easy access. The extension of the Vickery auction that solves the problem is called a Vickery-Clarke-Groves mechanism. We will discuss this mechanism later in the course. […]

]]> http://nsdl.library.cornell.edu/websites/expertvoices/info2040/archives/1795#comment-1219 Article Feed » Growing Networks Wed, 28 Feb 2007 05:05:01 +0000 http://nsdl.library.cornell.edu/websites/expertvoices/info2040/archives/1795#comment-1219 [...] Original post by Spero and a wordpress plugin by Elliott [...] […] Original post by Spero and a wordpress plugin by Elliott […]

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