• Journal of Electrical Engineering and Technology
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• 제3권4호
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• pp.509-513
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• 2008

In this paper, we investigate how generators' ramp-rate constraints may influence their equilibrium strategy formulation. In the market model proposed in this study, the generators' ramp-rate constraints are explicitly represented. In order to fully characterize the inter-temporal nature of the ramp-rate constraints, a dynamic game model is presented. The subgame perfect Nash equilibrium is adopted as the solution of the game and the backward induction procedure for the solution of the game is designed in this paper. The inter-temporal nature of the ramp-rate constraints results in the Markov property of the game, and we have found that the Markov property of the game significantly simplifies the subgame perfect Nash equilibrium characterization. Finally, a simple electricity market numerical illustration is presented for the successful application of the approach proposed.

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.62-67
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• 2003

An important aspect of the study of power system markets involves the assessment of strategic behavior of participants for maximizing their profits. In models of imperfect competition of a deregulated electricity system, the key task is to find the Nash equilibrium. In this paper, the bimatrix approach for finding Nash equilibria in electricity markets is investigated. This approach determines pure and mixed equilibria using the complementarity pivot algorithim. The mixed equilibrium in the matrix approach has the equal number of non-zero property. This property makes it difficult to reproduce a smooth continuous distribution for the mixed equilibrium. This paper proposes an algorithm for adjusting the quantization value of discretization to reconstruct a continuous distribution from a discrete one.

• 대한수학회지
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• 제36권4호
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• pp.813-828
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• 1999

In this paper, we give a Peleg type KKM theorem on G-convex spaces and using this, we obtain a coincidence theorem. First, these results are applied to a whole intersection property, a section property, and an analytic alternative for multimaps. Secondly, these are used to proved existence theorems of equilibrium points in qualitative games with preference correspondences and in n-person games with constraint and preference correspondences for non-paracompact wetting of commodity spaces.

• 충청수학회지
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• 제22권3호
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• pp.545-556
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• 2009

We show that two notions of asymptotic equilibrium and asymptotic equilibrium in variation for nonlinear differential systems are equivalent via $t_{\infty}$-similarity of associated variational systems. Moreover, we study the asymptotic equivalence between nonlinear system and its variational system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.380-382
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• 2002

An important aspect of the study of power system markets involves the assessment of strategic behavior of participants for maximizing their profits. In models of imperfect competition of a deregulated electricity system the key task is to find the Nash equilibrium. In this paper, the bimatrix approach for finding Nash equilibria in electricity markets is investigated. This approach determines pure and mixed equilibria using the complementarity pivot algorithm. The mixed equilibrium in the matrix approach has the equal number of non-zero property. This property makes it difficult to reproduce a smooth continuous distribution for the mixed equilibrium. This paper proposes an algorithm for adjusting the quantization value of discretization to reconstruct a continuous distribution from a discrete one.

• 한국환경과학회지
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• 제16권8호
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• pp.907-912
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• 2007

Ion exchange resin was used to remove silica ion at ultralow concentration. The effects of temperature, type of ion exchange resin and single/mixed-resin systems on removal efficiency were estimated. As temperature increased, the slope of concentration profile became stiff, and the equilibrium concentration was higher. In the single resin system, the removal of silica was continued up to 400 min, but the silica concentration was recovered to initial concentration after 400 min due to the effect of dissolved $CO_2$. In the mixed-resin system it took about 600 min to reach equilibrium. Because of faster cation exchange reaction than anion exchange reaction, the effect of $CO_2$ could be removed. Based on the experimental results carried out in the mixed-resin system, the selectivity coefficients of silica ion for each ion exchange resin were calculated at some specific temperatures. The temperature dependency of the selectivity coefficient was expressed by the equation of Kraus-Raridon type.

• 한국해안해양공학회지
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• 제7권3호
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• pp.233-240
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• 1995

비정상 이송확산 방정식의 고정도 수치계산법을 이용, 표사이동의 비평형성을 고려하는 항로매몰 예측법을 개발하고, 2차원 이동상 모형실험으로부터 얻어지는 항로매몰형상과 매몰량을 비교 검토함으로써 예측법의 적용성을 확인하였다. 아울러 이 예측법을 현지 scale의 model 항로에 적용, 매몰형상 및 매몰량을 예측함과 더불어 항로경사부에 있어서 복단면을 설치하여 항로내에서의 매몰량을 최소화하는 항로매몰 저감공법에 대하여 검토하였다. 그 결과. 항로경사부에 설치되는 복단면의 형상에 있어서, 복단면의 폭은 비평형상태의 표사이동이 평형상태로 회복됨에 요구되는 최소의 유하거리로서, 복단면의 깊이는 항로주변의 수심과의 비로서 결정되는 것을 알 수 있었다. 그러나 항로경사면에 설치되는 복단면의 폭과 깊이는, 역시 항로주변의 파랑과 흐름 그리고 저질입경 등과 같은 자연조건요인들에 의하여 크게 좌우되는 점을 감안할 때, 항로매몰저감을 목적으로 하는 복단면의 설치계획 및 시공에 앞서 세밀한 현지관측조사와 많은 자료수집 및 분석이 요구된다.

• 한국대기환경학회지
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• 제16권2호
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• pp.113-120
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• 2000

Effects of sea-salts on the properties of aerosol collected in a coastal region were studied by applying a gas-particle equilibrium model SCAPE to the measurement data from Korea Cheju Island in summer 1994. It was found that the observed higher ammonium concentrations in fine particles (PM2.5) than in TSP were caused by forced evaporation of ammonium in coarse fraction of aerosol by sea-salts and the degree of evaporation was quantified through an application of SCAPE. By subtracting the sea-salt fraction from the measured concentra-tions the changes of aerosol property were also studied. The concentrations of nitrate at both TSP and PM2.5 decreased when alkaline sea-salt fraction was removed from the measured data. Estimates of aerosol acidity increased for most samples with sea salt loadings, However in some cases with high mass fractions of sea-salt components the aerosol acidity of PM2.5 decreased slightly. This is though to be related with the formation of solid salt with the removal of sea-salts.

• 대한산업공학회지
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• 제13권2호
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• pp.65-77
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• 1987

Congestion occurs whenever users interfere with each other, while competing for scarce resources. In a congested market, such as a telecommunication service market, users of telecommunication services incur costs in using the service in addition to the price. The user's own time costs involved in learning to use the service, waiting for the service, and making use of the service are typically greater than the price of telecommunication services. A market equilibrium analysis is performed in which a method for user demand aggregation is developed. The effects of price changes on user demands and market demands for congested services are examined. It is found that total market demands may increase as the price for less-congested services increase under certain demand conditions. This suggests that a nonuniform pricing scheme for a congested service may improve the utilization of the congested system. The sign of price cross-elasticity for congested services is show to vary with demand conditions. A possible complementary property of congested services is found and the implication of such a property is discussed. It is argued that such a complementary property may lead to a cross subsidy in a market with congestion. Finally, comparisons between uniform pricing and nonuniform pricing policies are made. A specific numerical example is given to show that a nonuniform pricing policy may be Pareto superior to a uniform pricing policy.

• Transactions on Electrical and Electronic Materials
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• 제10권1호
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• pp.9-15
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• 2009

There is a growing demand for a high voltage silicone rubber composite with high mechanical property and high electrical property. The effect of modified cross-linking agent on the mechanical, electrical properties, and short-circuit test performance of silicone rubber insulators have been investigated. To use base polymer, the various silicone polymers were prepared by the equilibrium polymerization. Aluminum trihydrate surface was treated by vinyl silane. Liquid silicone rubber nanocomposite was prepared from the compounding of VPMPS, HPDMS, catalyst, and alumina trihydrate modified with 1,3,5-trivinyl-l,3,5-trimethylcyclotrisiloxane. The mechanical property and electrical property for insulation materials were measured, indicating the high tensile strength and the good short-circuit property.