• Water for future
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• v.19 no.4
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• pp.347-354
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• 1986

To predict flood runoff from rainfall and watershed Characteristics, Nash's parameters of N, K are needed to be determined. Also parameters of IUH N and K are derived by the moment method. Nash's model whose parameters are derived from rainfall characteristics is applied to the Wi-stream basin, which is a tributary located in the Nakdong river. For the derivation of IUH by applying linear conceptual model, the storage constant, K, with the rainfall characteristics was adopted as K=1.327 $$.$$$.$$$.$$$.$$$.$$ having a highly significant correlation coefficient, 0.970. Gamma function argumetn, N, derived with such rainfall characteristics was found to be N=0.032$$.$$$.$$$.$$$.$$$.$$ having a highly significant correlation coefficient, 0.970. From the tested results it is proved that Nash's IUH and consequently flood runoff can be predicted from rainfall characteristics.

• Water for future
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• v.19 no.3
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• pp.267-276
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• 1986

This study aims at the development of flood runoff model by comparing and analyzing nonlinear models with linear models in rier basins. The models which are used at the analysis are Nash model and Runoff function method as linear models, and Tank model and Storage function method as nonlinear models. The results, which are obtained from the analysis of these models by using hydrologic data of a representative basin in Nakdong river, Wi-chun basin, show that the peak time, peak flow and flood hydrogrphs by nonlinear models are better than those by linear models in comparison with observed ones, and that nonlinear models are suittable as flood runoff model.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.2
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• pp.97-106
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• 2005

This paper presents a method for evaluating the nash equilibrium of the Cournot model for N-Gencos in wholesale electricity market. In wholesale electricity market, the strategies of N-Gencos can be applied to the game model under the conditions, which the Gencos determine their strategies to maximize their benefit. Generally, the Lemke algorithm has known as the approach to evaluate the mixed nash equilibrium in the only two-player game model. In this paper, we have developed the necessary condition for obtaining the mixed nash equilibrium of N-player by using the Lemke algorithms. However, it is difficult to find the mixed nash equilibrium of two more players by using the analytic method since those have the nonlinear characteristics. To overcome the above problem, we have formulated the object function satisfied with the proposed necessary conditions for N-player nash equilibrium and applied the modified particle swarm optimization (PSO) method to obtain the equilibrium for N-player. To present the effectiveness the proposed necessary condition and the evaluation approach, this paper has shown the results of equilibrium of sample system and the cournot game model for 3-players.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.946-946
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• 2012

현재 국내 하천의 설계홍수량은 하천정비 기본계획이나 유역종합 치수계획 등을 통하여 고시 되고 있다. 이러한 설계홍수량은 홍수량 산정 지침에 따라 산정되며, 최종적으로 결정된 설계홍수량을 기준으로 하도계획이나 교량, 암거 등의 설계를 실시하였다. 현재 많은 수의 홍수조절용 다목적 댐과 강변저류지 등 각종 수리조작 구조물들이 축조되면서부터 홍수량을 시간별로 조절할 수 있게 되었지만, 미계측 유역에서는 유역의 유출량을 예측하기가 쉽지 않기 때문에 수리조작 구조물들의 효과를 예상하고 조작 및 운영방법을 결정하기 어려운 실정이다. 이러한 이유로, 본 연구에서는 미계측 유역 내 축조하는 수공 구조물의 최적 설계 및 운영방법 결정을 위하여 설계홍수량과 함께 합성단위도법을 적용한 수문곡선을 적용할 수 있도록 Nash 모형을 이용하였다. 유역의 유출특성이 반영된 대표단위도를 산정하기 위해 여러 유역의 다양한 형상계수를 이용하여, 도달시간과 첨두유량에 관한 회귀식을 산정하였다. 이렇게 산정된 회귀식을 여러 형태의 유역과 강우-유출 사상에 적용하여, 미계측 유역의 특정지점에서 발생의 개연성이 충분하고 수공구조물의 설계와 효과에 가장 중요하게 영향을 미칠 수 있는 설계홍수수문곡선을 도출하는 것을 목적으로 하였다. 본 연구의 결과로 나타나는 대표홍수수문곡선을 미계측 유역에 적용한다면 미지의 설계홍수량을 추정함과 동시에 설계홍수량에 상응하는 수문곡선을 도출하여 수공구조물 설계에 이용할 수 있을 것이라 기대한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.4
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• pp.379-384
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• 2014

This paper proposes a Cournot model that can be used to analyze the strategic behaviors of generation companies which try to maximize their profits in an imperfectly competitive electricity and carbon markets. The proposed model consists of two parts. First, the strategic behaviors of generation companies are modeled based on the Cournot theory. Second, the market operation is modeled based on the assumption that the market operator tries to maximize the total social welfare in consideration of environmental welfare. To find the Nash equilibrium of the proposed model, the two-level optimization technique is used. The proposed method has been applied to an illustrative example of oligopolistic markets. We found that the proposed method has strong potential to analyze the influence of the strategic biddings of the generation companies and the impact of renewable generator on markets where the competitiveness of the markets is not fully developed.

• Water for future
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• v.23 no.4
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• pp.421-434
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• 1990

The problems of hydrologic similarity among river basins was analyzed by a geomorphologic response model using Hortons*s ordering scheme. The Nash model was used for deriving the geomorphologic response function, and for the optimization of the responsefunction, imcomplete gamma function andRosso*s regression equation were used. The application of this method was tested on some observed flood data of Pyungchang river basin and Wi Stream basin and Bocheong stream, and predictions of hydrologic response were compared with that of the Moment method. The results show that the proposed model and dimensionless instantaneous unit hydrograph can be used for the runoff analysis of an ungauged basin and the analysis of hydrologic similarity.

• Journal of Advanced Navigation Technology
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• v.13 no.1
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• pp.87-96
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• 2009

The purpose of this paper is to analyze the power control problem in wireless communications with game theoretic approach. The major contribution of the present paper is that we formulated the problem as a game with a finite number of strategies while most of the previous game theoretic power control literatures modeled with continuous game in which there are infinite number of strategies. It should be noted that the closed-loop power control would be performed in a discrete manner, power up or down from the present level of power with fixed power control step size. We model the current closed-loop power control scheme with the famous Prisoner's dilemma model and show that the power-up strategy is Nash equilibrium. That is, every mobile tries to increase their power and approach to their maximal power. Thus, the outcome of current power control (Nash equilibrium) is inefficient. In order to attain efficient power control for the environment where ICI(Inter-Cell Interference is severe, we developed a new payoff function in which the penalty mechanism is introduced and derived conditions under which power-down becomes Nash equilibrium strategy for all players. Furthermore we examined the trajectory of equilibrium power when the power control game will be played repeatedly.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.20-30
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• 2008

This study is to analyse the hydrological behavior of agricultural reservoir using SWAT model. For the upsteam watershed of Gongdo water level gauge station in Anseongcheon watershed, the streamflows at 2 reservoir (Gosam and Geumgwang) locations and Gongdo station were simulated with reservoir inclusion and exclusion. The daily water surface area and storage have been calculated considering the stage-storage curve function of the reservoir. Afterwards, the reservoir operation module in SWAT was modified from original module in SWAT for daily reservoir discharge simulated by water balance equation. Model validation results were Nash-Sutcliffe model efficiency coefficients value of 0.55, root mean square error value of 2.33 mm/day. On the other hand, the simulation results of two reservoir exclusion were Nash-Sutcliffe model efficiency coefficients value of 0.37, root mean square error value of 2.91 mm/day. The difference of Nash-Sutcliffe model efficiency coefficients between the simulation results of two reservoir inclusion and exclusion at Gongdo station was 0.18. This is caused by the storage and release operation of agricultural reservoirs for the runoff occurred at 2 reservoir watersheds.

• The Journal of Internal Korean Medicine
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• v.30 no.2
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• pp.410-421
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• 2009

Objective : The aim of this study is to investigate the preventive effect of Injinchunggan-tang (YJCGT) & Injinysaryung-san (YJSRS) on MCD-diet-induced NASH in A/J mice. Methods : A/J mice were divided into 4 groups: Normal group (normal diet without any treatment). Control group (MCD diet only), YJCGT group (MCD diet with YJCGT), and YJSRS group (MCD diet with YJSRS). After 5 weeks, body weight, liver weight, biochemical parameters for liver function test, histological changes, and real-time PCR were assessed. Results : Mice lost body weight with the MCD diet and the YJCGT and YJSRS groups lost less than the control group, though showed no statistical significance. Liver weights were decreased by the MCD diet, but not significantly. In the liver function test, all the values were increased with the MCD diet, though some did not show significance. Alp and ALT levels were significantly less increased by YJCGT compared to the normal (p<0.05). All values were decreased or increased compared to the control by treatment though showed no significance possibly due to insufficient sample numbers. In histological findings of the livers. MCD-diet induced severe fatty change and collagen accumulation in the livers, but this fatty change was reduced in the YJCGT and YJYRS groups and fibrogenesis was inhibited significantly with p<0.05 and p<0.01, respectively. In real-time PCR analysis, YJCGT and YJYRS showed inhibitory effect on liver fibrogenesis by reducing associated gene expressions caused by MCD diet. Conclusion : YJCGT and YJSRS are considered to be possible candidates for the treatment of patients with NASH and/or liver fibrosis.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.639-642
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• 2003

This paper presents a method for evaluating the mixed nash equilibria of the Cournot model for N-Gencos. in wholesale electricity market. In the wholesale electricity market, the strategies of N-Genco. can be applied to the game model under the conditions which the Gencos. determine their stratgies to maximize their benefit. Generally, the Lemke algorithm is evaluated the mixed nash equlibria in the two-player game model. However, the necessary condition for the mixed equlibria of N-player are modified as the necessary condition of N-1 player by analyzing the Lemke algorithms. Although reducing the necessary condition for N-player as the one of N-1 player, it is difficult to and the mixed nash equilibria participated two more players by using the mathmatical approaches since those have the nonlinear characteristics. To overcome the above problem, this paper presents the generalized necessary condition for N-player and proposed the object function to and the mixed nash equlibrium. Also, to evaluate the mixed equilibrium through the nonlinear objective function, the Particle Swarm Optimization (PSO) as one of the heuristic algorithm are proposed in this paper. To present the mixed equlibria for the strategy of N-Gencos. through the proposed necessry condition and the evaluation approach, this paper proposes the mixed equilibrium in the cournot game model for 3-players.