Wireless sensor networks (WSNs) are becoming increasingly pervasive in a number of applications. Due to the nature of WSNs, one of their biggest constraints is limited node energy. As WSNs grow in popularity, the prevalent issue remains to keep wireless sensor nodes alive for as long as possible, or risk disrupting the network. This dissertation develops a model based on the principles of game theory to improve the energy efficiency of wireless sensor nodes and increase the network lifetime by influencing the way routing takes place. The benefit of this model is a routing algorithm that is easily implementable and increases network lifetime by improving energy efficiency in the network. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015

Wireless sensor networks (WSNs) are becoming increasingly pervasive in a number of applications. Due to the nature of WSNs, one of their biggest constraints is limited node energy. As WSNs grow in popularity, the prevalent issue remains to keep wireless sensor nodes alive for as long as possible, or risk disrupting the network. This dissertation develops a model based on the principles of game theory to improve the energy efficiency of wireless sensor nodes and increase the network lifetime by influencing the way routing takes place. The benefit of this model is a routing algorithm that is easily implementable and increases network lifetime by improving energy efficiency in the network. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015

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The Prisoner's Dilemma is a two player game where playing rationally leads to a suboptimal outcome for both players. The game is simple to analyze, but when it is played repeatedly, complex dynamics emerge. Recent research has shown the existence of extortionate strategies, which allow one player to win at least as much as the other. When one player plays such a strategy, the other must either decide to take a low payoff, or accede to the extortion, where they earn higher payoff, but their opponent receives a larger share. We investigate what happens when one player uses this strategy against an ``evolutionary'' player, who makes small changes to her strategy over time to increase her score, and show that there are cases where such a player will not evolve towards the optimal strategy of giving in to extortion.

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Proper procurement method selection is an integral part of project success. Better informed owners are able to more successfully select the project delivery systems that best suit their needs. This study utilizes utility theory to construct a framework to assist in the procurement decision making process. Through the use of expert weighting of important procurement criteria, real world projects were used to develop an overall threshold to which future owner's can compare their subsequent projects. This threshold, which marks the boundary between Design-Build and Design-Bid-Build, can be used to measure an owner's propensity to use either procurement method. It is fully tailorable to any owner, as owner-specific inputs are used. This ability for owners to objectify the largely subjective procurement decision making process allows owners to create a predictable, measurable trend, thereby improving their overall decision making ability. / US Navy (USN) author.

無線通訊現已成為我們生活中不可或缺的一部份。除了較傳統的無線技術應用如電視廣播及衛星通訊外，日漸普及的平版電腦與智能手機對無線技術也有殷切的需求。然而，有限的無線電頻譜是無線通訊的其中一個限制。在有限的資源下，如何在壅塞的網絡環境有效地分配無線電頻譜成為一個重要的議題。在這篇論文中，我們會利用博奕論來分析壅塞網絡內用戶的行為和一些嶄新的頻譜共用機制。 / 在論文的首部份，我們會利用壅塞賽局來模擬認知無線電網絡中未授權無線電頻段的使用者(次級用戶)的互動在四個不同的賽局下，我們會評估納殊均衡與社會最優的效能比。此外，我們會鑑別導致嚴重失效能的最壞情況。有見及此，我們提議一個能夠改善壅塞網絡系統吞吐量與資源方配公平性的半合作方案。透過具體指定合作用戶的資源分配，我們論證次級用戶具有真誠合作的動機。除此之外，我們也計算出半合作方案跟完全合作方案在系統吞吐量上比較的下限。從數值結果的觀察中，可見次級用戶的半合作模式已比沒有任何合作的方案更有效地改善系統的吞吐量。另外，在壅塞的網絡環境下，半合作方案的系統效能不僅與最理想的情況相近，而且能夠減低溝通的開銷及演算法的複雜性。 / 在論文的第二部份，我們會考慮流動網絡的壅塞情況。透過使用斯塔克爾伯格模型去模擬網絡供應商和消費者的互動，我們會集中研究兩種不同的收費方法。通過考慮網絡壅塞的負面影響，兩個收費方法在不同的地區會有不同的定價。在特定的網絡資源及消費者功利下，我們證實特定地區收費比無地區區分收費更為可取。特定地區收費不但能增加網絡供應商的收益，也能改善消費者的社會福利。 / Wireless technology has become an inseparable part of our daily lives. In addition to the traditional wireless applications, such as TV broadcast or satellite communication, the demand of wireless access from tablets and smartphones has increased tremendously. One big challenge of wireless communications is that spectrum resource is limited. When the resource is scarce, resource allocation in congested networks is of particular importance. In this thesis, we are interested to investigate the user behavior and new spectrum sharing mechanisms in congested networks using the tool of game theory. / In the first part of the thesis, we model the interaction of secondary users (SUs) in cognitive radio networks as congestion games. We evaluate the inefficiency of the Nash equilibria with the social optimal in four families of games. Most importantly, we identify the worst case scenario which leads to a severe performance loss. In order to tackle the problem, we propose a partial cooperation scheme which provides an alternative to improve the system throughput and fairness of the congested network. By specifying the allocation for cooperating users, we show that SUs have incentive to cooperate truthfully. Moreover, we give the performance bound of system throughput compared with full cooperation scheme. We also observe from the numerical results that the partial cooperation of SUs can greatly improve the system throughput comparing with no cooperation of SUs. In addition, the performance of the partial cooperation scheme is close to optimal in congested networks with a reduced overhead and complexity of the algorithm. / In the second part, we consider the congestion of current mobile networks. By modeling the interaction between a network service provider and the mobile subscribers with the Stackelberg game, we study two pricing schemes which suggested how prices should be set in different regions with the consideration of negative effects of congestion. Under given conditions of resource allocation and utility of subscribers, we show that region- specific pricing is more preferable than region-agnostic pricing which can improve both the revenue of the network service provider and the social welfare of the subscribers. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Law, Lok Man. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 153-164). / Abstracts also in Chinese. / Abstract --- p.i / Acknowledgement --- p.v / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Thesis Outline --- p.3 / Chapter 2 --- Congestion Games in Cognitive Radio Networks --- p.6 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.1.1 --- Overview --- p.6 / Chapter 2.1.2 --- Related Work --- p.10 / Chapter 2.2 --- Game Model --- p.12 / Chapter 2.2.1 --- A Congestion Game Framework --- p.13 / Chapter 2.2.2 --- Price of Anarchy (PoA) --- p.16 / Chapter 2.3 --- PoA Analysis --- p.19 / Chapter 2.3.1 --- Identical Games --- p.20 / Chapter 2.3.2 --- Player-specific Symmetric Games --- p.24 / Chapter 2.3.3 --- Resource-specific Symmetric Games --- p.27 / Chapter 2.3.4 --- Asymmetric Games --- p.32 / Chapter 2.4 --- Applications --- p.41 / Chapter 2.4.1 --- Uniform MAC --- p.41 / Chapter 2.4.2 --- Slotted Aloha --- p.45 / Chapter 2.4.3 --- Insights for System Design --- p.48 / Chapter 2.5 --- Summary --- p.49 / Chapter 2.6 --- Appendix --- p.51 / Chapter 2.7 --- Notations --- p.53 / Chapter 3 --- Partial Cooperation in Cognitive Radio Networks --- p.54 / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.1.1 --- Overview --- p.54 / Chapter 3.1.2 --- Related Work --- p.58 / Chapter 3.2 --- System Model --- p.61 / Chapter 3.3 --- Different Medium Access Control Schemes --- p.63 / Chapter 3.3.1 --- Benchmark MAC Schemes --- p.63 / Chapter 3.3.2 --- Priority-based Partial Cooperation Scheme (PPCS) --- p.66 / Chapter 3.4 --- PPCS with Identical Data Rates --- p.70 / Chapter 3.4.1 --- Random Priority PPCS (PPCS-RP) --- p.71 / Chapter 3.4.2 --- Fixed Priority PPCS (PPCS-FP) --- p.77 / Chapter 3.4.3 --- Numerical Results --- p.80 / Chapter 3.5 --- PPCS with Heterogeneous Data Rates --- p.85 / Chapter 3.5.1 --- Sparsely Populated PUs --- p.87 / Chapter 3.5.2 --- Densely Populated PUs --- p.95 / Chapter 3.6 --- PPCS with incomplete information --- p.98 / Chapter 3.6.1 --- The Allocation Rule --- p.98 / Chapter 3.6.2 --- Incentive for Group Formation --- p.100 / Chapter 3.6.3 --- Truth Revelation --- p.103 / Chapter 3.6.4 --- Numerical Results --- p.105 / Chapter 3.7 --- Summary --- p.111 / Chapter 3.8 --- Notations --- p.114 / Chapter 4 --- Regional Pricing in Mobile Networks --- p.115 / Chapter 4.1 --- Introduction --- p.115 / Chapter 4.1.1 --- Overview --- p.115 / Chapter 4.1.2 --- Related Work --- p.117 / Chapter 4.2 --- System Model --- p.119 / Chapter 4.2.1 --- Stackelberg Game --- p.121 / Chapter 4.2.2 --- Our Model --- p.123 / Chapter 4.3 --- The Two Pricing Schemes --- p.127 / Chapter 4.3.1 --- Region-specific Pricing --- p.127 / Chapter 4.3.2 --- Region-agnostic Pricing --- p.128 / Chapter 4.3.3 --- Extension to Multiple Regions --- p.130 / Chapter 4.4 --- Comparison of Schemes --- p.131 / Chapter 4.4.1 --- Overview of Two-region Case --- p.131 / Chapter 4.4.2 --- Revenue Ratio --- p.135 / Chapter 4.4.3 --- Utilization Ratio --- p.142 / Chapter 4.5 --- Summary --- p.144 / Chapter 4.6 --- Notations --- p.146 / Chapter 5 --- Conclusions and Future Work --- p.147 / Chapter 5.1 --- Conclusion --- p.147 / Chapter 5.2 --- Future Work --- p.148 / Chapter 5.2.1 --- Congestion Games in Cognitive Radio Networks --- p.148 / Chapter 5.2.2 --- Partial Cooperation in Cognitive Radio Networks --- p.149 / Chapter 5.2.3 --- Regional Pricing in Mobile Networks --- p.151 / Bibliography --- p.153

Coalition stability is an important concept in coalition formation. One common assumption in many stability criteria in non-transferable utility games is that the preference relations of each agent is publicly known so that a coalition is said to be stable if there is no objection by any sub-group of agents according to the publicly known preferences. / However, in many software agent applications, this assumption is not true. Instead, agents are modeled as individuals with private belief and decisions are made according to those beliefs instead of common knowledge. There are two types of uncertainty here. First, uncertainty in beliefs regarding the environment means that agents are also uncertain about their preferences. Second, an agent's actions can be influenced by his belief regarding other agents' preferences. Such uncertainties have impacts on the coalition's stability which is not reflected in the current stability criteria. / In this thesis, we extend the classic stability concept of the non-transferable utility core by proposing new belief based stability criteria under uncertainty, and illustrate how the new concept can be used to analyze the stability of a new type of belief-based coalition formation game. Mechanisms for reaching solutions of the new stable criteria is proposed and a real life application example is studied. / Chan, Chi Kong. / Adviser: Ho-Fung Leung. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3594. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 101-103). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

by Chan Chi Shing. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves [78-81].