• 한국정보과학회논문지:소프트웨어및응용
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• 제27권3호
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• pp.257-265
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• 2000

자연계의 많은 합리적인 이기적 개체들 사이에는 수많은 선택적 갈등이 존재한다. 반복적 죄수의 딜레마(Iterated Prisoner's Dilemma: IPD)게임은 합리적인 이기적 개체들 사이의 경쟁과 협동에 대한 선택적 갈등을 다루는데, 사회, 경제 및 생물 시스템에서 협동의 진화를 연구하는데 사용되어 왔다. 이제까지는 게임자의 수와 협동의 관계, 기계학습의 일환으로서의 전략학습, 그리고 이득함수가 협동에 미치는 영향 등에 관한 연구가 있었는데, 이 논문에서는 진화방식을 이용하여 이득함수에 따른 협동연합의 크기와 지역화가 NIPD(N-player IPD)게임에서 협동의 진화에 미치는 영향에 대해 밝히고자 한다. 시뮬레이션 결과 협동개체에 대한 이득함수의 기울기가 배반에 대한 이득함수의 기울기보다 급하거나 최소 연합의 크기가 작을수록 협동연합의 정도가 높게 나타나며 상호작용하는 이웃의 크기가 작을수록 협동연합의 정도가 높게 진화됨을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권11호
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• pp.5253-5270
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• 2016

With device-to-device (D2D) communications, an inactive user terminal can be utilized as a relay node to support multi-hop communication so that connective experience of the cell-edge user as well as the capacity of the whole system can be significantly improved. In this paper, we investigate the spectrum sharing for a cooperative relay assisted D2D communication underlying a cellular network. We formulate a joint relay selection and channel assignment problem to maximize the throughput of the system while guaranteeing the quality of service (QoS) requirements of cellular users (CUs) and D2D users (DUs). By exploiting coalition formation game theory, we propose two algorithms to solve the problem. The first algorithm is designed based on merge and split rules while the second one is developed based on single user's movement. Both of them are proved to be stable and convergent. Simulation results are presented to show the effectiveness of the proposed algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2286-2309
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• 2016

Overlay networks have been widely deployed upon the Internet by Service Providers (SPs) to provide improved network services. However, the interaction between each overlay and traffic engineering (TE) as well as the interaction among co-existing overlays may occur. In this paper, we adopt both non-cooperative and cooperative game theory to analyze these interactions, which are collectively called hybrid interaction. Firstly, we model a situation of the hybrid interaction as an n+1-player non-cooperative game, in which overlays and TE are of equal status, and prove the existence of Nash equilibrium (NE) for this game. Secondly, we model another situation of the hybrid interaction as a 1-leader-n-follower Stackelberg-Nash game, in which TE is the leader and co-existing overlays are followers, and prove that the cost at Stackelberg-Nash equilibrium (SNE) is at least as good as that at NE for TE. Thirdly, we propose a cooperative coalition mechanism based on Shapley value to overcome the inherent inefficiency of NE and SNE, in which players can improve their performance and form stable coalitions. Finally, we apply distinct genetic algorithms (GA) to calculate the values for NE, SNE and the assigned cost for each player in each coalition, respectively. Analytical results are confirmed by the simulation on complex network topologies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권10호
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• pp.3810-3830
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• 2015

In this paper, we investigate the differential game theoretic approach for distributed dynamic cooperative power control in cognitive radio ad hoc networks (CRANETs). First, a payoff function is defined by taking into consideration the tradeoff between the stock of accumulated power interference to the primary networks and the dynamic regulation of the transmit power of secondary users (SUs). Specifically, the payoff function not only reflects the tradeoff between the requirement for quickly finding the stable available spectrum opportunities and the need for better channel conditions, but also reveals the impact of the differentiated types of data traffic on the demand of transmission quality. Then the dynamic power control problem is modeled as a differential game model. Moreover, we convert the differential game model into a dynamic programming problem to obtain a set of optimal strategies of SUs under the condition of the grand coalition. A distributed dynamic cooperative power control algorithm is developed to dynamically adjust the transmit power of SUs under grand coalition. Finally, numerical results are presented to demonstrate the effectiveness of the proposed algorithm for efficient power control in CRANETs.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.669-673
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• 1998

This paper makes a study of the Shapley value in cooperative fuzzy games, games with fuzzy coalitions, which enable the representation of players' participation degree to each coalition. The Shapley value has so far been introduced only in an class of fuzzy games where a coalition value is not monotone with respect to each player's participation degree. We consider a more natural class of fuzzy games such that a coalition value is monotone with regard to each player's participation degree. The properties of fuzzy games in this class are investigated. Four axioms of Shapley functions are described and a Shapley function of a fuzzy fame in the class is given.

• 산업경영시스템학회지
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• 제8권12호
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• pp.107-118
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• 1985

This paper is considerd a coalition formation problem with several game theoretical hypothesis and analyzed its usefulness in elect ion games.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4661-4680
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• 2016

Cognitive radio (CR) technology is an effective solution to the spectrum scarcity issue. Collaborative spectrum sensing is known as a promising technique to improve the performance of spectrum sensing in cognitive radio networks (CRNs). However, collaborative spectrum sensing is vulnerable to spectrum data falsification (SSDF) attack, where malicious users (MUs) may send false sensing data to mislead other secondary users (SUs) to make an incorrect decision about primary user (PUs) activity, which is one of the key adversaries to the performance of CRNs. In this paper, we propose a coalition based malicious users detection (CMD) algorithm to detect the malicious user in CRNs. The proposed CMD algorithm can efficiently detect MUs base on the Geary'C theory and be modeled as a coalition formation game. Specifically, SSDF attack is one of the key issues to affect the resource allocation process. Focusing on the security issues, in this paper, we analyze the power allocation problem with MUs, and propose MUs detection based power allocation (MPA) algorithm. The MPA algorithm is divided into two steps: the MUs detection step and the optimal power allocation step. Firstly, in the MUs detection step, by the CMD algorithm we can obtain the MUs detection probability and the energy consumption of MUs detection. Secondly, in the optimal power allocation step, we use the Lagrange dual decomposition method to obtain the optimal transmission power of each SU and achieve the maximum utility of the whole CRN. Numerical simulation results show that the proposed CMD and MPA scheme can achieve a considerable performance improvement in MUs detection and power allocation.

• 산업경영시스템학회지
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• 제42권3호
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• pp.15-24
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• 2019

Fair Allocation of profits or costs arising from joint participation by multiple individuals or entities with different purposes is essential for their continuing involvement and for their dissatisfaction reduction. In this research, fair allocation of the profits of forming a grand coalition in Three-Echelon Supply Chain (TESC) game that is composed of manufacturer, distributor and retailer, is studied. In particular, the solutions of the proportional method of profit, the proportional method of marginal profit, and Shapley value based on cooperative game theory are proved to be in the desirable characteristics of the core. The proportional method of profit and the proportional method of marginal profit are often used because of their ease of application. These methods distribute total profit in proportion to profits or marginal profits of each game participant. In addition, Shapley value can be defined as the average marginal profit when one game player is added at a time. Even though the calculation of the average of all possible marginal profits is not simple, Shapley value are often used as a useful method. Experiments have shown that the solution of the incremental method, which calculates the marginal cost of adding game players in the order of manufacturers, distributors and retailers, does not exist in the core.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2157-2165
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• 2017

This study deals with the design of the mechanism in which demand response (DR) resources are traded in the power generation market. In general, a DR aggregator (DRA), which extends DR resources and provides technical support, is central to this mechanism. In this study, power users, called DR customer (DRC), participate in load reduction and are also modeled to participate directly in DR-related bidding. The DRA provides incentives to the DRC, indirectly impacting the market, and the DRC use the bid parameters strategically. We present the conditions for finding Nash Equilibrium (NE) in game problems of various participants including market operators, and analyze the characteristics of DRA and DRC related models. It also analyzes the impact of the participants on the market according to various types of competition and coalitions between DRA and DRC.

• 한국위성정보통신학회논문지
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• 제10권1호
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• pp.49-55
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• 2015

인지무선 네트워크에서 스펙트럼 센싱은 우선사용자에게 간섭을 주지 않기 위해 기본적으로 수행해야 하는 단계이다. 스펙트럼 센싱에 요구되는 샘플 수는 2차 사용자의 성능에 직접적으로 영향을 주기 때문에, 2차 사용자의 성능과 우선사용자에 대한 간섭은 트레이드오프 관계에 있다. 스펙트럼 센싱에 필요한 샘플 수는 요구되는 오검출 확률, 검출확률 및 우선 사용자의 최소 요구 SNR로 부터 얻어진다. 우선 사용자 센싱에 요구되는 SNR은 2차 사용자의 전송반경과 관련 있기 때문에, 2차사용자들을 모아 센싱집합으로 구성하고 요구되는 전송영역을 최소화시킴으로써 스펙트럼 센싱에 요구되는 우선사용자의 SNR을 완화시킬 수 있다. 따라서 스펙트럼 센싱에 필요한 최소 샘플 수를 줄임으로써 인지무선 네트워크의 전송량을 향상시킬 수 있다. 본 논문에서는 이를 위해 센싱집합인 클러스터링을 통해 게임이론으로 클러스터의 크기에 따라 얻는 이득과 손실을 트레이드오프로 디자인하고, 시뮬레이션을 통해 제안된 방법의 성능을 확인한다.