• Laboraroty Animal Research
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• v.34 no.4
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• pp.133-139
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• 2018

Nonalcoholic steatohepatitis (NASH) is becoming common chronic liver disease because of the increasing global prevalence of obesity and consequently Nonalcoholic fatty liver disease (NAFLD). However, the mechanism for progression of NAFLD to NASH and then cirrhosis is not completely understood, yet. The triggering of these hepatic diseases is thought from hepatocyte injury caused by over-accumulated lipid toxicity. Injured hepatocytes release damage-associated molecular patterns (DAMPs), which can stimulate the Kupffer cells (KCs), liver-resident macrophages, to release pro-inflammatory cytokines and chemokines, and recruit monocyte-derived macrophages (MDMs). The increased activation of KCs and recruitment of MDMs accelerate the progression of NAFLD to NASH and cirrhosis. Therefore, characterization for activation of hepatic macrophages, both KCs and MDMs, is a baseline to figure out the progression of hepatic diseases. The purpose of this review is to discuss the current understanding of mechanisms of NAFLD and NASH, mainly focusing on characterization and function of hepatic macrophages and suggests the regulators of hepatic macrophages as the therapeutic target in hepatic diseases.

• 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.

• 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.

• 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.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.5
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• pp.470-478
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• 2019

Purpose: The incidence of non-alcoholic fatty liver disease (NAFLD) in children is gradually increasing. The aim of this study was to investigate the use of serum adiponectin and soluble adiponectin receptor 2 (soluble Adipo R2) levels for the diagnosis of fatty liver disease in obese and overweight children. Methods: The study included 51 obese and overweight children between the ages of 6 and 18 years diagnosed with NAFLD using ultrasonography and 20 children without fatty liver disease. Patients whose alanine transaminase level was two times higher than normal (${\geq}80U/L$) were included in the non-alcoholic steatohepatitis (NASH) group. Results: NASH was observed in 11 (21.6%) of the patients with NAFLD. The incidence of obesity was higher in patients with NASH (80% and 45%, p=0.021). While the adiponectin levels were similar in patients with NAFLD and those without, they were below the normal level in the whole study group. Adiponectin and soluble Adipo R2 levels of patients with NASH were lower than those in patients without NASH; however, this difference was not statistically significant (p=0.064 and p=0.463). Soluble Adipo R2 levels in obese patients with NAFLD were higher than those in obese children without NAFLD (p<0.001). Conclusion: Soluble adiponectin receptor 2 level is a noninvasive marker that can be used for the diagnosis of NAFLD in obese children.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.27 no.4
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• pp.236-245
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• 2024

Purpose: The prevalence of nonalcoholic steatohepatitis (NASH) is increasing with the increasing prevalence of childhood obesity. Although NASH has a high risk of progression to liver fibrosis and cirrhosis, few studies have reported noninvasive markers for predicting hepatic fibrosis in children. This study aimed to evaluate and compare the diagnostic accuracies of serologic biomarkers and scoring systems for hepatic fibrosis in obese children with NASH. Methods: A total of 96 children were diagnosed with NASH based on liver biopsy findings and divided into two groups according to the degree of liver fibrosis: mild (stage 0-1) or advanced (stage 2-4). Clinical and laboratory parameters and serum levels of hyaluronic acid and type IV collagen were measured. The aspartate aminotransferase/platelet ratio index (APRI) and fibrosis-4 (FIB-4) score were calculated. Results: Among the noninvasive markers, only serum type IV collagen level and FIB-4 were significantly different between the two groups. The area under the receiver operating curve of each biomarker and scoring system was 0.80 (95% confidence interval [CI]: 0.70-0.90) for type IV collagen at an optimal cutoff of 148 ng/mL (sensitivity 69.8%, specificity 84.6%), followed by 0.69 (95% CI: 0.57-0.83) for APRI, 0.68 (95% CI: 0.56-0.80) for FIB-4, and 0.65 (95% CI: 0.53-0.77) for hyaluronic acid. Conclusion: Type IV collagen as a single noninvasive serologic biomarker for hepatic fibrosis and FIB-4 as a hepatic fibrosis score are beneficial in predicting advanced hepatic fibrosis and determining proper diagnosis and treatment strategies before fibrosis progresses in obese children with NASH.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.187-193
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• 2012

Nash Equilibrium (NE) is as useful tool for investigating a participant's strategic generation quantity in a competitive electricity market. Cournot model may give a mixed strategy NE instead of a pure strategy when transmission constraints are considered. A mixed strategy is difficult to compute, complicated to understand conceptually, and hard to implement in an electricity market practically. This paper presents that a mixed strategy does not appear in Stackelberg leader-follower model even under a transmission congestion. A solution method is proposed for the leader-follower model under a nondifferentiable space of a strategy variable. Based on the pure strategy NE with a transmission line congested, the merit of leader-follower model is shown from a social welfare point of view.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2143-2149
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• 2010

Market price and curtailment amounts of the Demand Resource Market(DRM) are determined by competition between electricity consumers. An important aspect of the DRM involves the assessment of strategic behavior of participants for maximizing their profits. This paper presents economic equilibrium models for simulating imperfect competition among electricity consumers in the DRM and analyzes the models at Nash Equilibrium of Game Theory. The proposed demand functions and supply functions of DRM are based on the Demand Resource Market Rules in Korean electricity market. Simulation results show that the models are adequate for obtaining Nash Equilibrium of consumers' competitive curtailment.

• East Asian Economic Review
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• v.21 no.2
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• pp.167-197
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• 2017

I build a small open economy (SOE) dynamic stochastic general equilibrium (DSGE) model to investigate the effect of a heterogeneous wage contract between regular and temporary workers on a macroeconomic volatility in a financially fragile economy. The imperfect financial market condition is captured by a quadratic financial adjustment cost for borrowing foreign assets, and the labor market friction is captured by a Nash bargaining process which is only available to the regular workers when they negotiate their wages with the firms while the temporary workers are given their wage which simply equals the marginal cost. As a result of impulse responsesto a domestic productivity shock, the higher elasticity of substitution between two types of workers and the lower weight on the regular workers in the firm's production process induce the higher volatilities in most variables. This is reasoned that the higher substitutability creates more volatile wage determination process while the lower share of the regular workers weakens their Nash bargaining power in the contract process.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.4
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• pp.1-9
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• 2013

We propose a heuristic algorithm for war-game model that is appropriate for warfare in which the maneuver of the attacker is relatively certain. Our model is based on a multi-weapon extention of the Lanchester's square law. However, instead of dealing with the differential equations, we use a multi-period linear approximation which not only facilitates a solution method but also reflects discrete natures of warfare. Then our game model turns out to be a continuous game known to have an ${\varepsilon}$-Nash equilibrium for all ${\varepsilon}{\geq}0$. Therefore, our model approximates an optimal warfare strategies for both players as well as an efficient reinforcement of area defense system that guarantees a peaceful equilibrium. Finally, we report the performance of a practical best-response type heuristic for finding an ${\varepsilon}$-Nash equilibrium for a real-scale problem.