• KIPS Transactions on Computer and Communication Systems
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• v.10 no.4
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• pp.93-100
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• 2021

The Ethereum shard system for solving the scalability problem of the blockchain has a load balancing issue, which is modeled as a graph partitioning problem. In this paper, we propose an adaptive online weighted graph partitioning algorithm that can negotiate between two utility of the shard system using the game theory's bargaining solution. The bargaining solution is an axiomatic solution that can fairly determine the points of conflict of utility. The proposed algorithm was improved to apply the existing online graph partitioning algorithm to the weighted graph, and load balancing was performed efficiently through the design considering the situation of the sharding system using the extension of Nash bargaining solution, which is extended to apply solution to non-convex feasible set of bargaining problem. As a result of the experiment, it showed up to 37% better performance than typical load balancing algorithm of shard system.

• Information and Communications Magazine
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• v.26 no.7
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• pp.24-29
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• 2009

협동적 게임 이론(cooperative game theory)은 다중 사용자들이 어떻게 하면 한정된 자원을 효율적이고 공평하게 공유할 수 있는지에 촛점을 맞추며 이론적인 바탕을 제공한다. 본고에서는 다수의 멀티미디어 사용자들이 협동적 게임 이론중 협상 해법(bargaining solutions)을 이용하여 어떻게 통신 및 네트워크 자원을 효율적이고 공평하게 공유할 수 있는지 알아본다. 또한, 이러한 협상 해법들을 바탕으로 한 자원 공유가 멀티미디어 사용자에게 어떠한 의미를 갖는지 알아보도록 한다. 마지막으로, 이러한 게임 이론을 이용한 자원 관리가 다양한 형태의 통신 및 네트워크에 어떻게 사용될 수 있으며, 미래의 활용 가능성을 알아보도록 한다.

• Journal of KIISE:Information Networking
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• v.37 no.6
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• pp.415-419
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• 2010

Bandwidth is an extremely valuable and scarce resource in a wireless network. Therefore, efficient bandwidth management is necessary in order to provide high quality service to users with different requirements. In this paper, we propose a bandwidth reservation algorithm based on Nash Bargaining Solution. The proposed algorithm has low complexity and are quite flexible in the different situations of network. Simulation results indicate that the proposed scheme has excellent performance than other existing schemes.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.8
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• pp.215-222
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• 2021

In order to alleviate the limited resource problem and interference problem in cellular networks, the dual connectivity technology has been introduced with the cooperation of small cell base stations. In this paper, we design a new efficient and fair resource allocation scheme for the dual connectivity technology. Based on two different bargaining solutions - Generalizing Tempered Aspiration bargaining solution and Gupta and Livne bargaining solution, we develop a two-stage radio resource allocation method. At the first stage, radio resource is divided into two groups, such as real-time and non-real-time data services, by using the Generalizing Tempered Aspiration bargaining solution. At the second stage, the minimum request processing speeds for users in both groups are guaranteed by using the Gupta and Livne bargaining solution. These two-step approach can allocate the 5G radio resource sequentially while maximizing the network system performance. Finally, the performance evaluation confirms that the proposed scheme can get a better performance than other existing protocols in terms of overall system throughput, fairness, and communication failure rate according to an increase in service requests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.400-406
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• 2014

In this paper, we propose an approach to minimizing total power consumption by deploying multiple clean-up robots simultaneously in a given area. For this, we propose to use the cooperative game theoretic approaches (i.e., Nash bargaining solution (NBS)) such that the robots can optimally and fairly negotiate the area division based on available resources and characteristics of the area, thereby leading to the minimum total power consumption. We define a utility function that includes power consumptions for characteristics of areas and the robots can agree on a utility pair based on the NBS. Simulation results show that the proposed approach can reduce the total average power consumption by 15-30% compared to a random area division approach.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.10
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• pp.299-308
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• 2023

As the spectrum shortage problem has accelerated by the emergence of various services, New Radio-Unlicensed (NR-U) has appeared, allowing users who communicated in licensed bands to communicate in unlicensed bands. However, NR-U network users reduce the performance of Wi-Fi network users who communicate in the same unlicensed band. In this paper, we aim to simultaneously maximize the fairness and throughput of the unlicensed band, where the NR-U network users and the WiFi network users coexist. First, we propose an optimal power allocation scheme based on Monte Carlo Policy Gradient of reinforcement learning to maximize the sum of rates of NR-U networks utilizing rate-splitting multiple access in unlicensed bands. Then, we propose a channel occupancy time division algorithm based on sequential Raiffa bargaining solution of game theory that can simultaneously maximize system throughput and fairness for the coexistence of NR-U and WiFi networks in the same unlicensed band. Simulation results show that the rate splitting multiple access shows better performance than the conventional multiple access technology by comparing the sum-rate when the result value is finally converged under the same transmission power. In addition, we compare the data transfer amount and fairness of NR-U network users, WiFi network users, and total system, and prove that the channel occupancy time division algorithm based on sequential Raiffa bargaining solution of this paper satisfies throughput and fairness at the same time than other algorithms.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.221-224
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• 2011

본 논문에서는 중첩 된 WBAN(Wireless Body Area Network) 환경에서 비경쟁 전송구간의 신뢰성 있는 전송을 위해 한정된 자원(비경쟁 전송구간)을 각각의 WBAN에게 할당하는 방안을 제안한다. 이를 위해 협동적 게임 이론(cooperative game theory)을 바탕으로 한정된 자원(비경쟁 전송구간)을 효율적이고 공평하게 할당 할 수 있도록 내쉬중재(Nash arbitration) 기법을 통한 자원 할당 방안을 살펴본다. 내쉬중재 협상해법을 통해 WBAN 간 비경쟁 전송구간의 충돌 없이 신뢰성 있는 전송을 보장한다. 또한, 각 WBAN의 비경쟁 전송 구간 내의 디바이스 우선순위와 할당받은 timeslot의 개수를 고려하여 전략 선택에 따른 형평성과 각 WBAN이 비경쟁전송 구간 내에 요구하는 최소한의 timeslot을 보장한다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.7
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• pp.311-316
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• 2002

It has been a basic model for the present electric power industry that more than two generators compete, and thereby the market clearing price and the generation schedules are determined through the bid process. In order for this paradigm to be applicable to real electric power systems and markets, it is necessary to reflect many physical and economic constraints related to frequency and transmission in the dispatching schedule. The paper presents an approach to deriving a Nash bargaining solution in a competitive electricity market where multiple generators are playing with the system operator who mitigates the transmission congestion to minimize the total transaction cost. In this study, we take the effect of the line flows and the role of system operator into the Game. Finally, a case study has been demonstrated to verify the proposed cooperative game.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.463-468
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• 2016

The overall performance of multiuser systems significantly depends on how effectively and fairly manage resources shared by them. The efficient resource management strategies are even more important for multimedia users since multimedia data is delay-sensitive and massive. In this paper, we focus on resource allocation based on a game-theoretic approach, referred to as Nash bargaining solution (NBS), to provide a quality of service (QoS) guarantee for each user. While the NBS has been known as a fair and optimal resource management strategy, it is challenging to find the NBS efficiently due to the computationally-intensive task. In order to reduce the computation requirements for NBS, we propose an approach that requires significantly low complexity even when networks consist of a large number of users and a large amount of resources. The proposed approach linearizes utility functions of each user and formulates the problem of finding NBS as a convex optimization, leading to nearly-optimal solution with significantly reduced computation complexity. Simulation results confirm the effectiveness of the proposed approach.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.63-69
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• 2014

For the safety messages in IEEE 802.11p vehicles network environment(WAVE), strict periodic beacon broadcasting requires status advertisement to assist the driver for safety. WAVE standards apply multiple radios and multiple channels to provide open public road safety services and improve the comfort and efficiency of driving. Although WAVE standards have been proposed multi-channel multi-radio, the standards neither consider the WAVE multi-radio environment nor its effect on the beacon broadcasting. Most of beacon broadcasting is designed to be delivered on only one physical device and one control channel by the WAVE standard. also conflict-free channel assignment of the fewest channels to a given set of radio nodes without causing collision is NP-hard, even with the knowledge of the network topology and all nodes have the same transmission radio. Based on the latest standard IEEE 802.11p and IEEE 1609.4, this paper proposes an interference aware-based channel assignment algorithm with Nash bargaining solution that minimizes interference and increases throughput with wireless mesh network, which is deigned for multi-radio multi-cahnnel structure of WAVE. The proposed algorithm is validated against numerical simulation results and results show that our proposed algorithm is improvements on 8 channels with 3 radios compared to Tabu and random channel allocation algorithm.