Title of dissertation : MULTIMEDIA SOCIAL NETWORKS : GAME THEORETIC MODELING AND EQUILIBRIUM ANALYSIS

Title of dissertation: MULTIMEDIA SOCIAL NETWORKS: GAME THEORETIC MODELING AND EQUILIBRIUM ANALYSIS Yan Chen, Doctor of Philosophy, 2011 Dissertation directed by: Professor K. J. Ray Liu Department of Electrical and Computer Engineering Multimedia content sharing and distribution over multimedia social networks is more popular now than ever before: we download music from Napster, share our images on Flickr, view user-created video on YouTube, and watch peer-to-peer television using Coolstreaming, PPLive and PPStream. Within these multimedia social networks, users share, exchange, and compete for scarce resources such as multimedia data and bandwidth, and thus influence each other’s decision and performance. Therefore, to provide fundamental guidelines for the better system design, it is important to analyze the users’ behaviors and interactions in a multimedia social network, i.e., how users interact with and respond to each other. Game theory is a mathematical tool that analyzes the strategic interactions among multiple decision makers. It is ideal and essential for studying, analyzing, and modeling the users’ behaviors and interactions in social networking. In this thesis, game theory will be used to model users’ behaviors in social networks and analyze the corresponding equilibria. Specifically, in this thesis, we first illustrate how to use game theory to analyze and model users’ behaviors in multimedia social networks by discussing the following three different scenarios. In the first scenario, we consider a non-cooperative multimedia social network where users in the social network compete for the same resource. We use multiuser rate allocation social network as an example for this scenario. In the second scenario, we consider a cooperative multimedia social network where users in the social network cooperate with each other to obtain the content. We use cooperative peer-to-peer streaming social network as an example for this scenario. In the third scenario, we consider how to use the indirect reciprocity game to stimulate cooperation among users. We use the packet forwarding social network as an example. Moreover, the concept of “multimedia social networks” can be applied into the field of signal and image processing. If each pixel/sample is treated as a user, then the whole image/signal can be regarded as a multimedia social network. From such a perspective, we introduce a new paradigm for signal and image processing, and develop generalized and unified frameworks for classical signal and image problems. In this thesis, we use image denoising and image interpolation as examples to illustrate how to use game theory to re-formulate the classical signal and image processing problems. MULTIMEDIA SOCIAL NETWORKS: GAME THEORETIC MODELING AND EQUILIBRIUM ANALYSIS