• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.509-516
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• 2011

This paper studies a novel method to find the profit-maximizing Nash Equilibriums in allocating generation quantities with consideration of ramp-rates under competitive market environment. Each GenCo in a market participates in a game to maximize its profit through competitions and play a game with bidding strategies. In order to find the Nash equilibriums it is necessary to search the feasible combinations of GenCos' strategies which satisfy every participant's profit and no one wants various constraints. During the procedure to find Nash equilibriums, the payoff matrix can be simplified as eliminating the dominated strategies. in each time interval. Because of the ramp-rate, generator's physically or technically limits to increase or decrease outputs in its range, it can restrict the number of bidding strategies of each generator at the next stage. So in this paper, we found the Nash Equilibriums for multi-stage generation allocation game considering the ramp-rate limits of generators. In the case studies, we analyzed the generation allocation game for a 12-hour multi-stage and compared it with the results of dynamic economic dispatch. Both of the two cases were considered generator's ramp-rate effects.

• Journal of Power Electronics
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• v.9 no.6
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• pp.919-928
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• 2009

Microgrids (MGs) are typically comprised of distributed generators (DGs) including renewable energy sources (RESs), storage devices and controllable loads, which can operate in either interconnected or isolated mode from the main distribution grid. This paper introduces a novel dynamic programming (DP) approach to MG optimization which takes into consideration the coordination of energy supply in terms of heat and electricity. The DP method has been applied successfully to several cases in power system operations. In this paper, a special emphasis is placed on the uncontrollability of RESs, the constraints of DGs, and the application of demand response (DR) programs such as directed load control (DLC), interruptible/curtaillable (I/C) service, and/or demand-side bidding (DSB) in the deregulated market. Finally, in order to illustrate the optimization results, this approach is applied to a couple of examples of MGs in a certain configuration. The results also show the maximum profit that can be achieved.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1463-1471
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• 2005

This paper proposes an agent-based scheduling method fur semiconductor wafer fabrication facilities with hard inter-operation temporal constraints. The scheduling problem is to find the feasible schedules that guarantee both logical and temporal correctness. A proposed multi-agent based architecture is composed of scheduling agents, workcell agents, and machine agents. A scheduling agent computes optimal schedules through bidding mechanisms with a subset or entire set of the workcell agents. A dynamic planning-based approach is adopted for the scheduling mechanism so that the dynamic behaviors such as aperiodic job arrivals and reconfiguration can be taken into consideration.

• Journal of Internet Computing and Services
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• v.11 no.5
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• pp.105-117
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• 2010

In recent years, dynamic collaboration (DC) among cloud providers (CPs) is becoming an inevitable approach for the widely use of cloud computing and to realize the greatest value of it. In our previous paper, we proposed a combinatorial auction (CA) based cloud market model called CACM that enables a DC platform among different CPs. The CACM model allows any CP to dynamically collaborate with suitable partner CPs to form a group before joining an auction and thus addresses the issue of conflicts minimization that may occur when negotiating among providers. But how to determine optimal group bidding prices, how to obtain the stability condition of the group and how to distribute the winning prices/profits among the group members in the CACM model have not been studied thoroughly. In this paper, we propose to formulate the above problems of cooperative negotiation in the CACM model as a bankruptcy game which is a special type of N-person cooperative game. The stability of the group is analyzed by using the concept of the core and the amount of allocationsto each member of the group is obtained by using Shapley value. Numerical results are presented to demonstrate the behaviors of the proposed approaches.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2220-2226
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• 2018

Electric vehicles (EVs) are significant resources for demand response (DR). Thus, it is essential for EV aggregators to quantitatively evaluate their capability for DR. In this paper, a concept of dynamic equivalent battery (DEB) is proposed as a metric for evaluating the DR performance using EVs. The DEB is the available virtual battery for DR. The capacity of DEB is determined from stochastic calculation while satisfying the charging requirements of each EV, and it varies also with time. Further, a new indicator based on the DEB and time-varying electricity prices, named as value of DEB (VoDEB), is introduced to quantify the value of DEB coupled with the electricity prices. The effectiveness of the DEB and the VoDEB as metrics for the DR performance of EVs is verified with the simulations, where the difference of charging cost reduction between direct charging and optimized bidding methods is used to express the DR performance. The simulation results show that the proposed metrics accord well with the DR performance of an EV fleet. Thus, an EV aggregator may utilize the proposed concepts of DEB and VoDEB for designing an incentive scheme to EV users, who participate in a DR program.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.569_570
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• 2009

This paper presents a methodology to find the profit maximized Nash Equilibriums of each generator(or GenCo), which considers the Ramp-rate of each generator under a competitive market environment. The ramp-rate of a generator is one of the physical or technical constraints of a generator and means the ability to increase or decrease the output instantaneously. In this paper, we found several Nash Equilibriums of the generation allocation problem through Dynamic Programming in a competitive market. Individual generators participate in a game to maximize its profit through competitions and play a game with bidding strategies of its generation quantities in a spot market.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.384-385
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• 2006

현재와 같은 경쟁적 전력수급 시장에서 경쟁력을 확보하기 위해서는 모든 발전사업자는 이득 극대화를 위한 전략이 필요할 것이다. 이에 여러 발전 방식 중에서도 타 에너지원의 발전설비보다 에너지원의 생산, 저장, 소비 등 다양한 전략이 가능한 양수발전을 선택하여 효과적인 대응 방안을 찾아보고자 한다. 본 논문에서는 발전 경쟁 시장 체제하에서 동적 게임이론을 적용하여, 양수발전을 소유한 발전 사업자의 최적 입찰 전략 알고리즘을 제시한다.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1223-1230
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• 2005

The dynamic nature of the A/E/C industry, rapidly changing global market environments, and lowest cost competitive bidding make it difficult to survive in global design markets. To understand the global design markets, a case study has been undertaken. The top 150 global design firms represented in the ENR (Engineering News Record) from 1995 to 2003 are classified into three groups for the case study. First group is the firms which advanced in rank from 1995. Second group is the firms which maintained its rank from 1994 until 2003. Third group is the firms which went down in rank from 1995 until 2003. However, finding key factors and changing business strategies of successful top design firms are the fundamental goals in this paper. After examinations of case studies, this paper concludes and suggests that professionalization, M&A strategies, patrons of the government, and academic support are needed to be successful in the global design & engineering industry.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.78-82
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• 2001

Most of current Internet auction systems are simple server programs that partly automated the function of the conventional auction house. These system do not provide sufficient independence, distribution and parallelism between the functions of the conventional auction house. In there are automated by server program, but still users need to execute a repetitive task to monitor the dynamic progress of a certain auction, decide proper bid price, and submit the bid. Another problem is that they support only single as English auction and Dutch auction, but they do not support the double auctions are superior to the single auction with respect to speed., efficiency, and the fair distribution of profit. In this paper, we present design and implement of an agent-based continuous double auction system, called CoDABot, in order to mitigate the limitations of current auctions system. CoDABot supports continuous double auction, provides various bidding agent for users to select, and has been implemented into a multi-agent system that realize more independent, distributed, and parallel subsystems.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.226-234
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• 2004

Dynamic nature of the A/E/C industry, rapidly changing global market environment, and lowest cost competitive bidding make it difficult to survive in global engineering markets. To understand of the global design&engineering market, a case study has been undertaken. The top 150 global design forms represented in the ENR(Engineering News Record) from 1995 to 2003 are classified three groups for the case study, First group is the firms that its rank is getting raised from 1995. Second group is the firms keep holding its rank from 1994 until 2003. Third group is the firms that its rank has gone down from 1995 until 2003. However, finding key factors and changing business strategies of successful top design fm are the fundamental goals in this paper, After examined case study, this paper concludes and suggests that professionalization, M&A strategies, patrons of government, and academic supporting are needed to be succeeding in the global design & engineering industry.