• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.19-27
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• 2017

Recently, the hydrological model Soil Water Assessment Tool (SWAT) has been applied in many watersheds in South Korea. This study estimated parameters in SWAT for calibrating streamflow in long-term drought periods. Therefore, we focused on the continuous severe drought periods 2014~2015, and understand the model calibrated parameters. The SWAT was applied to a $366.5km^2$ Gongdo watershed by using 14 years (2002~2015) daily observed streamflow (Q) including two years extreme drought period of 2014~2015. The 9 parameters of CN2, CANMX, ESCO, SOL_K, SLSOIL, LAT_TIME, GW_DELAY, GWQMN, ALPHA_BF were selected for model calibration. The SWAT result by focusing on 5 normal years (2002~2006) calibration showed the 14 years average Nash-Sutcliffe model efficiency (NSE) for Q and 1/Q with 0.78 and 0.58 respectively. On the other hand, the 14 years average NSEs of Q and 1/Q by focusing on 2 drought years (2014~2015) calibration were 0.86 and 0.76 respectively. Thus, we could infer that the SWAT calibration trial by focusing on drought periods data can be a good approach to calibrate both high flow and low flow by controlling the 9 drought affected parameters.

• Advances in materials Research
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• v.11 no.1
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• pp.75-90
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• 2022

In this paper, functionality of soft computing algorithms such as Group method of data handling (GMDH), Random forest (RF), Random tree (RT), Linear regression (LR), M5P, and artificial neural network (ANN) have been looked out to predict the compressive strength of concrete mixed with marble powder. Assessment of result suggests that, the overall performance of ANN based model gives preferable results over the different applied algorithms for the estimate of compressive strength of concrete. The results of coefficient of correlation were maximum in ANN model (0.9139) accompanied through RT with coefficient of correlation (CC) value 0.8241 and minimum root mean square error (RMSE) value of ANN (4.5611) followed by RT with RMSE (5.4246). Similarly, other evaluating parameters like, Willmott's index and Nash-sutcliffe coefficient value of ANN was 0.9458 and 0.7502 followed by RT model (0.8763 and 0.6628). The end result showed that, for both subsets i.e., training and testing subset, ANN has the potential to estimate the compressive strength of concrete. Also, the results of sensitivity suggest that the water-cement ratio has a massive impact in estimating the compressive strength of concrete with marble powder with ANN based model in evaluation with the different parameters for this data set.

• Journal of the Korea Society of Computer and Information
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• v.14 no.12
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• pp.33-40
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• 2009

We study Interpreted Systems, ATL, and ATEL to capture the notion of time, knowledge, and strategy which are important in the analysis of multi-agent systems and propose strategic constraints based on subgame perfect Nash equilibrium of game theory as one of the solutions for the issues of ATEL which an agent can access the current state of the whole system when making up his strategy even when he should be uncertain about the state, and no explicit representation of actions in ATEL models makes some natural situations harder to model. Also, we present strategic constraints-based Interpreted Systems for model checking of multi-agent systems.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.201-207
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• 2009

Recently effective spectrum resource technologies have been studied using a game theorectical approach for cognitive radio networks. Radio resource management is required an effective scheme because the performance of a radio communication system much depends on it's effectiveness. In this paper, we suggest a game theoretical algorithm for adaptive power control which is required an effect scheme in cognitive radio networks. It will be a distributed network. In the network distributed cognitive radio secondary users require an adaptive power control. There are many results which are suggested some possibility of game theoretical approaches for communication resource sharing. However, we suggest a practical game algorithm to achieve Nash equilibrium of all secondary users using a Nash equilibrium theorem in this paper. Particularly, a game model was analyzed for adaptive power control of a cognitive radio network, which is involved in DSSS (Direct Sequence Spread Spectrum) techniques. In case of K=63 and N=12 in the DSSS network, the number of iteration was less than maximum 200 using the suggested algorithm.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.60-60
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• 2021

Non-alcoholic fatty liver disease (NAFLD), especially including non-alcoholic steatohepatitis (NASH) is one of the common diseases with 25% of prevalence globally, but there is no thera-peutic access available. Amomum villosum var. xanthioides (Wall. ex Baker) T.L.Wu & S.J.Chen (AX), which is a medicinal herb and traditionally used for treating digestive tract disorders in Asia countries. We aimed to examine pharmacological effects of ethyl acetate fraction of AX (AXEF) against ER stress-induced NASH mice model using C57/BL6J male mice by tunicamycin (TM, 2 mg/kg) injection focusing on the oxidative stress. Mice were orally administrated AXEF (12.5, 25, or 50 mg/kg), silymarin (50 mg/kg) or distilled water daily for 5 days, and outcomes for fatty liver, inflammation, and oxidative stress were measured in serum or liver tissue levels. AXEF drastically attenuated hepatic ER stress-induced NASH which were evidenced by decreases of li-pid droplet accumulations, serum liver enzymes, hepatic inflammations, and cell death signals in the hepatic tissue or serum levels. Interestingly, AXEF showed potent antioxidant effects by quenching of reactive oxidative stress and its final product of lipid peroxide in the hepatic tissue, specifically increase of metallothionein (MT). To confirm underlying actions of AXEF, we ob-served that AXEF increase MT1gene promoter activities in the physiological levels. Collectively, AXEF showed antioxidant properties on TM-induced ER stress of NASH by enhancement of MTs.

• Journal of Ginseng Research
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• v.43 no.2
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• pp.196-208
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• 2019

Background: Nonalcoholic steatohepatitis (NASH) is one of the chronic inflammatory liver diseases and a leading cause of advanced liver fibrosis, cirrhosis, and hepatocellular carcinoma. The main purpose of this study was to clarify the effects of GBCK25 fermented by Saccharomyces servazzii GB-07 and pectinase, on NASH severity in mice. Methods: Six-wk-old male mice were fed either a normal diet (ND) or a Western diet (WD) for 12 wks to induce NASH. Each group was orally administered with vehicle or GBCK25 once daily at a dose of 10 mg/kg, 20 mg/kg, 100 mg/kg, 200 mg/kg, or 400 mg/kg during that time. The effects of GBCK25 on cellular damage and inflammation were determined by in vitro experiments. Results: Histopathologic analysis and hepatic/serum biochemical levels revealed that WD-fed mice showed severe steatosis and liver injury compared to ND-fed mice. Such lesions were significantly decreased in the livers of WD-fed mice with GBCK25 administration. Consistently, mRNA expression levels of NASH-related inflammatory-, fibrogenic-, and lipid metabolism-related genes were decreased in the livers of WD-fed mice administered with GBCK25 compared to WD-fed mice. Western blot analysis revealed decreased protein levels of cytochrome P450 2E1 (CYP2E1) with concomitantly reduced activation of c-Jun N-terminal kinase (JNK) in the livers of WD-fed mice administered with GBCK25. Also, decreased cellular damage and inflammation were observed in alpha mouse liver 12 (AML12) cells and RAW264.7 cells, respectively. Conclusion: Administration of GBCK25 ameliorates NASH severity through the modulation of CYP2E1 and its associated JNK-mediated cellular damage. GBCK25 could be a potentially effective prophylactic strategy to prevent metabolic diseases including NASH.

• Water for future
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• v.20 no.2
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• pp.117-126
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• 1987

A Synthetic unit hydrograph method was suggested for the representation of a direct runoff hydrograph with empirical geomorphologic laws and geomorphologic parameters by applying geomorphologic instantaneous unit hydrograph theory and Rossois results of application of GIUH theory to the Nash Model which is a linear reservoir model. The shape parameter m and scale parameter k can be derived by the Horton's empirical geomorphologic laws $R_A,R_B,R_L$ when ordered according to Strahler's ordering Scheme, main stream length and using the maximum velocity for the dynamic characteristics of a river basin, The derived response function was tested on some observed flood datas and showed promising. For the determination of the shape parameter m, eq. (16) was showed applying and m showed a good regression with the size of basin area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.1
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• pp.79-86
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• 1986

The parameters of Nash's conceptual model of Instantaneous Unit Hydrograph, n and k, are estimated by the moment method from the rainfall and runoff data in 18 watersheds of drainage area ranging 53.7 to 1,361 sq. km. Then, these parameters are represented in terms of watershed characteristics by F-test and multiple correlation method. The unit hydrographs by this study are compared with the unitgraphs obtained from the recorded runoff data and agreements are good. The results imply that unit hydrographs in ungaged watersheds can be derived by watershed characteristics only through Nash's model.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1142-1146
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• 2004

The objective of this study is to the test applicability of SLURP on Soyanggang-dam watershed. The area of this watershed is $2,694km^2$ and mean elevation and slope is 650 m and $23^{\circ}$ respectively. Topographical parameters were derived from DEM using TOPAZ and SLURPAZ. NDVI was calculated from multi-temporal NOAA/AVHRR images. The daily meteorological data and hydrograph during $1999\~2001$ were selected for model calibration and performance tests. Weather elements (dew-point temperature, solar radiation, maximum and minimum temperature, relative humidity) were required from the S meteorological stations near the study area. The model parameters of each land cover class were optimized by sensitivity analysis and SCE-UA method. Runoff rate shows $49.33\%\~64.06\%$. Simulated results during 4 years were estimated by Nash-Sutcliffe efficiency and WMO volume error. Nash-Sutcliffe efficiency shows $0.61\~0.75$ and WMO volume error shows $6.1\%-18.8\%$.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.63-72
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• 2010

This study aims to make a decision about the rational option for a multipurpose dams development of the Tumen river basin so that the adjoining countries will effectively deal with the chronic problems and fully satisfy the fast growing demand of water and power. It has been thus far investigated that the interests between North Korea and China closely depend on the selected option, and they are not well compatible with each other. These situations are defined in terms of the cooperative two-person nonzero-sum game. The Nash bargaining model is then applied to contemplate the rational option, considering two scenarios of economic growth of the North Korea. After analyzing the model, it was expected that 1) two multipurpose dams must be cooperatively developed, and 2) their benefits should be allocated according to demand of each country. The authors finally suggest that a cooperative organisation be established to effectively manage the dams beyond the border of the countries.