Theses and Dissertations from UMD
Permanent URI for this communityhttp://hdl.handle.net/1903/2
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
Browse
3 results
Search Results
Item Multimedia Social Networks: Game Theoretic Modeling and Equilibrium Analysis(2011) Chen, Yan; Liu, K. J. Ray; Electrical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)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.Item THE P-T-t HISTORY OF A BARROVIAN SEQUENCE IN DUTCHESS COUNTY, NEW YORK, AND THE ADJACENT PART OF CONNECTICUT(2009) Chen, Yan; Brown, Michael; Piccoli, Philip; Geology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The P-T-t history of a Barrovian sequence in Dutchess County, New York and the adjacent part of Connecticut was studied. Using the average P-T mode in THERMOCALC, the following P-T results were calculated for the garnet, staurolite, kyanite and sillimanite-K-feldspar zones (1sigma uncertainties): 5.2±0.8 kbar, 570±12°C; 5.9±1.1 kbar, 557±12°C; 6.4±1.1 kbar, 600±29°C; and 7.4±1.4 kbar, 752±68°C, respectively. Phase equilibria modeling in the MnNCKFMASHTO system yields peak P-T results consistent with the average P-T results. Monazite ages were obtained for the garnet, staurolite, kyanite and sillimanite-K-feldspar zones (2 sigma uncertainties): 455±6 and 453±10 Ma; 451±9 and 438±8 Ma; 478±6, 431±4 and 425±8 Ma; 533±7 Ma, 507±6, 506±4 Ma and 472±5 Ma, respectively. These ages help to constrain the timing of the Taconic and Salinic orogenic events.Item Information, Consumer Choice and Firm Strategy in an Experience Good Market(2008-08-19) Chen, Yan; Jin, Ginger; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This paper models how consumers make brand choice when they have limited information. In an experience good market with frequent product entry and exit, consumers face two types of information problems: first, they have limited information about product existence; second, even if they know a product exists, they do not have full information about its quality until they purchase and consume the product. In this paper, I incorporate purchase experience and brand advertising as two sources of information, and examine how consumers utilize them in a dynamic process. Specifically, to address the awareness problem, I model the consumer choice set as a function of experience and advertising, which varies across consumers and evolves over time. In terms of quality, I allow a first-time consumer to infer product quality from advertising. Once she buys the product, she learns the quality perfectly. To better capture the dynamics, I incorporate habit formation conditional on each consumer's purchase history. The model is estimated using the AC Nielsen homescan data in Los Angeles, which records grocery shopping histories for 1,402 households over six years. Taking ready-to-eat cereal as an example, I find that consumers learn about new products quickly and form strong habits. More specifically, advertising has a significant effect informing consumers of product existence and signaling product quality. However, advertising's prestige effect is not significant. I also find that incorporating limited information about product existence leads to larger estimates of the price elasticity. Then I use instrument variables based on differentiated-products firm competition models to address the endogeneity problem of price and advertising with unobserved brand characteristics. Based on the IV estimates, I summarize the substitution pattern and simulate consumer choices under counterfactual experiments to evaluate a number of brand marketing strategies and a policy on banning children-oriented cereal advertising.