• Journal of Communications and Networks
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• 제18권4호
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• pp.658-669
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• 2016

The tremendous increase in mobile data traffic coupled with fierce competition in wireless industry brings about spectrum scarcity and bandwidth fragmentation. This inevitably results in asymmetric-valued long term evolution (LTE) spectrum allocation that stems from different timing for twice improvement in capacity between competing operators, given spectrum allocations today. This motivates us to study the economic effects of asymmetric-valued LTE spectrum allocation. In this paper, we formulate the interactions between operators and users as a hierarchical dynamic game framework, where two spiteful operators simultaneously make spectrum acquisition decisions in the upper-level first-price sealed-bid auction game, and dynamic pricing decisions in the lower-level differential game, taking into account user subscription dynamics. Using backward induction, we derive the equilibrium of the entire game under mild conditions. Through analytical and numerical results, we verify our studies by comparing the latest result of LTE spectrum auction in South Korea, which serves as the benchmark of asymmetric-valued LTE spectrum auction designs.

• 수산경영론집
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• 제25권2호
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• pp.89-102
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• 1994

This paper is to survey the major results of the game-theoretic models and recent research directions of the literature on auctions and competitive biddings. This paper classifies the auctions and competitive biddings into the following four major types:(i) English auction, (ii) Dutch auction, (iii) the first-price sealed-bid auction, (iv) the second-price sealed-bid auction. In order to survey the major ideas related to auctions and competitive biddings, we use two representative theoretical models developed under the game-theoretic framework : (i) the independent private value model are summarized as follows ; (1) The Dutch auction and the first-price auction are strategically equivalent, and so are the English auction and the second-price auction. (2) At the symmetric equilibria, the expected selling price is the same for all four types of auction. Meanwhile, the major results of the general model are as follows ; (1) When bidders are uncertain about their value extimate, the English and second-price auctions are not equivalent, but the dutch and the first-price auctions are still strategically equivalent. (2) The English auction generates the higher expected prices than the second-price auction. Also, when bidders are risk-neutral, the second-price auction generated higher average prices than the Dutch and the first-price auctions.

• 한국멀티미디어학회논문지
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• 제13권1호
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• pp.153-160
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• 2010

일반적인 온라인 게임의 목표는 자신이 소유한 캐릭터의 레벨을 얻는 것인데, 캐릭터의 성장을 빠르게 하기 위해서는 캐릭터에 맞는 아이템을 갖추어야 한다. 그렇지만 각 유저들이 게임 중에 획득하는 아이템은 자신이 소유한 캐릭터의 특징과 맞지 않는 경우가 많다. 그래서 사용자들은 각자의 아이템을 교환한다. 아이템을 교환하는데 있어서 게임이 제공해주는 기능은 제한적인 경우가 많다. 게임 아이템을 효율적으로 매매하기 위해서는 인터넷 아이템 거래 사이트처럼 다양한 거래 방식을 게임 내에서도 지원할 필요가 있다. 일반적인 매매 방식 외에 경매와 같은 방법을 지원함으로써 사용자들은 아이템 거래를 편리하게 할 수 있다. 본 논문에서는 국내에서 인터넷으로 서비스되고 있는 몇몇 온라인 게임에서 구현된 아이템 매매 기능과 인터넷 아이템 거래 사이트의 기능을 분석하여 각각의 장점을 살린 경매방식 전자상거래 설계 기법을 제안한다. 제안하는 방법을 사용하면 특정한 아이템을 매매하고자하는 사용자들이 관련된 정보를 신속하게 얻을 수 있고, 다양한 거래 방법을 통하여 필요한 아이템을 매매할 수 있다.

• 한국통신학회논문지
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• 제38A권11호
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• pp.944-954
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• 2013

인지무선(cognitive radio)기술은 특정 주파수에 대해 권한을 가진 주 사용자가 자신의 주파수를 사용하지 않을 때 생기는 유휴 대역을 특정 주파수에 대해 권한이 없는 부 사용자가 사용할 수 있도록 하는 기술이다. 본 논문에서는 인지무선 네트워크에 옥션 게임 이론을 적용시켜, 주파수 가격과 옥션 주기를 동시에 고려한 주 사용자의 이득을 최대화 할 수 있도록 하는 알고리즘을 제안한다. 부 사용자들이 제시한 주파수양의 비율에 따라 주 사용자의 주파수를 분배하는 옥션이 반복적으로 진행되면서 주 사용자는 최적의 주파수 가격을 찾게 되며, 찾아진 주파수 가격 정보와 본 논문에서 새로 제시한 주 사용자의 효용함수를 이용해 최적의 옥션 주기를 찾게 된다. 동시에 주 사용자는 찾아진 최적의 옥션 주기에 맞는 주파수 가격을 최종적으로 결정하게 된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권9호
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• pp.3312-3334
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• 2015

In this paper, a mechanism for spectrum allocation in overlay cognitive radio networks is proposed. In overlay cognitive radio networks, the secondary users (SUs) must first sense the activity of primary users (PUs) to identify unoccupied spectrum bands. Based on their different contributions for the spectrum sensing, the SUs get payoffs that are computed by the fusion center (FC). The unoccupied bands will be auctioned and SUs are asked to bid using payoffs they earned or saved. Coalitions are allowed to form among SUs because each SU may only need a portion of the bands. We formulate the coalition forming process as a coalition forming game and analyze it by game theory. In the coalition formation game, debtor-creditor relationship may occur among the SUs because of their limited payoff storage. A debtor asks a creditor for payoff help, and in return provides the creditor with a portion of transmission time to relay data for the creditor. The negotiations between debtors and creditors can be modeled as a Bayesian game because they lack complete information of each other, and the equilibria of the game is investigated. Theoretical analysis and numerical results show that the proposed auction yields data rate improvement and certain fairness among all SUs.

• 한국국방경영분석학회지
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• 제14권1호
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• pp.63-83
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• 1988

This study is concerned with the equilibrium bidding strategy and the optimal auction design of sequential auction with a reserve price and an entry fee. It is assumed that each bidder has a fixed reservation value and draws the reservation values of other bidders independently in the same distribution and may obtain at most one object to be sold. Under such assumptions, the sequential auction will be analyzed by the game theoretic approach. The purpose of this paper is, in the sequential auction, to find the equilibrium bidding strategy and to design the optimal auction under the equilibrium bidding strategy. The equilibrium bidding strategy and the optimal auction design are further analyzed with respect to change of the reserve price, the entry fee, and the number of bidders and objects. Specially, the auctioneer's expected revenue for each auction is obtained and analyzed.

• 한국국방경영분석학회지
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• 제13권2호
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• pp.63-83
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• 1987

This study is concerned with the equilibrium bidding strategy and the optimal auction design of sequential auction with a reserve price and an entry fee. It is assumed that each bidder has a fixed reservation value and draws the reservation values of other bidders independently in the same distribution and may obtain at most one object to be sold. Under such assumptions, the sequential auction will be analyzed by the game theoretic approach. The purpose of this paper is, in the sequential auction, to find the equilibrium bidding strategy and to design the optimal auction under the equilibrium bidding strategy. The equilibrium bidding strategy and the optimal auction design are further analyzed with respect to change of the reserve price, the entry fee, and the number of bidders and objects. Specially, the auctioneer's expected revenue for each auction is obtained and analyzed.

• KIEE International Transactions on Power Engineering
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• 제5A권1호
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• pp.85-92
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• 2005

In this paper, Nash equilibriums of generation markets are investigated using a game theory application for simplified competitive electricity markets. We analyze the characteristics of equilibrium states in N-company spot markets modeled by uniform pricing auctions and propose a new method for obtaining Nash equilibriums of the auction. We assume that spot markets are operated as uniform pricing auctions and that each generation company submits its bids into the auction in the form of a seal-bid. Depending on the bids of generation companies, market demands are allocated to each company accordingly. The uniform pricing auction in this analysis can be formulated as a non-cooperative and static game in which generation companies correspond to players of the game. The coefficient of the bidding function of company-n is the strategy of player-n (company-n) and the payoff of player-n is defined as its profit from the uniform price auction. The solution of this game can be obtained using the concept of the non-cooperative equilibrium originating from the Nash idea. Based on the so called residual demand curve, we can derive the best response function of each generation company in the uniform pricing auction with N companies, analytically. Finally, we present an efficient means to obtain all the possible equilibrium set pairs and to examine their feasibilities as Nash equilibriums. A simple numerical example with three generation companies is demonstrated to illustrate the basic idea of the proposed methodology. From this, we can see the applicability of the proposed method to the real-world problem, even though further future analysis is required.

• 대한전기학회논문지:전력기술부문A
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• 제52권6호
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• pp.340-346
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• 2003

This paper presents a game theory application for an analysis of uniform price auction in a simplified competitive electricity market and analyzes the properties of Nash equilibrium for various conditions. We have assumed that each generation firm submits his bid to a market in the form of a sealed bid and the market is operated as a uniform price auction. Two firms are supposed to be the players of the market, and we consider the maximum generation quantity constraint of one firm only. The system demand is assumed to have a linear relationship with market clearing prices and the bidding curve of each firm, representing the price at which he has a willingness to sell his generation quantity, is also assumed to have a linear function. In this paper, we analyze the effects of maximum generation quantity constraints on the Nash equilibrium of the uniform price auction. A simple numerical example with two generation firms is demonstrated to show the basic idea of the proposed methodology.

• 대한가정학회지
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• 제48권5호
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• pp.1-15
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• 2010

The purpose of this study was to find the characteristics of internet auction user groups by the levels of addictive tendencies among high school students. The questionnaire was conducted from December 16 to 23, 2008, and 288 high school students who were living in Cheongju area were selected. The main results were as follows. First, 13.4% of respondents were visiting internet site almost every day, and about 20% of them stayed more than 2 hours for visiting the internet auction site. Second, the price of purchasing goods through internet auction site(shopping mall) was less than 50,000 won. Third, the level of addictive tendencies of respondents was under average(2.08 out of 5 point scale), and about 10% of them evaluated by themselves as an internet auction. Fourth, relatively higher addictive tendencies group showed the characteristics such as lower self-esteem, higher depression, and higher feeling of isolation, internet related(general internet use, internet shopping, and internet game) addictive tendencies, and more often visiting and staying longer in internet auction sites and other internet sites.