• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1992-1996
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• 2007

The Kaplan turbine model has been tested and analized. The blade angle and the guide vane opening of the turbine model were designed to be varied according to the best combination of guide vane and runner blade opening. When the changes in head and output were comparatively large, the efficincy drop were small, so the efficiency characteristics and stability of the entire operating condition were maintained in good condition. These results showed that the developed model in this study will be suitable for small hydro power stations with large changes in head and load.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.3
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• pp.213-219
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• 2000

Combination of AHP priorities is essential in combining opinions of multiple experts. There are two ways to get combined priorities: one is to combine the pairwise matrices and obtain the priority from it and another is to combine the individual priorities. In this paper, we use a Dirichlet probability model to combine the priorities from multiple experts. The resulting combined priority is an expected value of the model, which is a function of some measure of the homogeneity and credibility of the group of experts. We give some interpretations of this measure and illustrate them by numerical example.

• Korean Journal of Health Education and Promotion
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• v.4 no.2
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• pp.9-31
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• 1987

This study was conducted because of the investigator's concern for the high incidence and fatal nature of cancer in prime years of human life. The purpose of this study was to investigate risk factors on compilance for preventive health behavior of cancer. The data on which the analysis was based come from a survey of 828 married men & women, 40-59 years old. The instrument of the study were 'Health Belief Model' by Becker. The Data was analyzed using X--test, t-test, ANOVA, Pearson's Correlation Coefficient, Stepwise Multiple Regression. The followings were the result; 1. The examined group had a higher scores than the non-examined group in health belief variables. (p<0.001) 2. The higher level of health belief variables, the higher level of compliance for preventive health behavior is. (p<0.001) 3. The Stepwise Multiple Regression of compliance for preventive health behavior on the variables in the health belief model; Approximataly 65.5% of the variance of compliance for preventive health behavior was accounted for by health concern, susceptibility and barriers in combination. This meant that other factors seemed to influence preventive health behavior since the linear combination of variables failed to explain the remaining 34.5% of preventive health behavior of cancer. It tended to cost doubt on the usefulness of 5 variables in this model. Therefore further study to investigate the influential factors preventive health behavior of cancer is necessary.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.5
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• pp.9-16
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• 2011

Curve Numbers (CN) for the combination of land use and hydrologic soil group were regionalized at Imha Watershed using Long-term Hydrologic Impact Assessment (L-THIA) coupled with SCE-UA. The L-THIA was calibrated during 1991-2000 and validated during 2001-2007 using monthly observed direct runoff data. The Nash-Sutcliffe (NS) coefficients for calibration and validation were 0.91 and 0.93, respectively, and showed high model efficiency. Based on the criteria of model calibration, both calibration and validation represented 'very good' fit with observe data. The spatial distribution of direct surface runoff by L-THIA represented runoff from Thiessen pologen at Subi and Sukbo rain gage station much higher than other area due to the combination of poor hydrologic condition (hydrologic soil C and D group) and locality heavy rainfall. As a results of hydrologic condition and treatment for land use type based on calibrated CNs, forest is recommended to be hydrologically modelled dived into deciduous, coniferous, and mixed forest due to the hydrological difference. The CNs for forest and upland showed the poor hydrologic condition. The steep slope of forest and alpine agricultural field make high runoff rate which is the poor hydrologic condition because CN method can not consider field slope. L-THIA linded with SCE-UA could generated a regionalized CNs for land use type with minimized time and effort, and maximized model's accuracy.

• Nuclear Engineering and Technology
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• v.37 no.2
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• pp.139-150
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• 2005

A robust control design procedure for a nuclear reactor has been developed and experimentally validated on the Penn State TRIGA research reactor. The utilization of the robust controller as a component of an autonomous control system is also demonstrated. Two methods of specifying a low order (fourth-order) nominal-plant model for a robust control design were evaluated: 1) by approximation based on the 'physics' of the process and 2) by an optimal Hankel approximation of a higher order plant model. The uncertainty between the nominal plant models and the higher order plant model is supplied as a specification to the ,u-synthesis robust control design procedure. Two methods of quantifying uncertainty were evaluated: 1) a combination of additive and multiplicative uncertainty and 2) multiplicative uncertainty alone. The conclusions are that the optimal Hankel approximation and a combination of additive and multiplicative uncertainty are the best approach to design robust control for this application. The results from nonlinear simulation testing and the physical experiments are consistent and thus help to confirm the correctness of the robust control design procedures and conclusions.

• Korean Journal of Computational Design and Engineering
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• v.11 no.6
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• pp.393-402
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• 2006

The purpose of this study is to develop mechanisms of nD model-based design by the combination of 2D drawing standards and 3D building models from the current 2D and text-based design. The aim of this study can be archived by defining the 2D model extension definitions for the IFC model development and harmonizing existing 2D standards. The paper examines 1) 3D Representation of Building Element and Building Services element, and 2D Model extension of IFC2X.2, 2) Basic development of additional 2D element that should be added to IFC model, and 3) mapping method between current 2D standard and IFC2.X2. Following this approach, the interoperability problem between 3D model and 2D drawing can be solved and finally an extended data model could be developed.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.258-258
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• 2018

In this study, a hydraulic flow model and an error correction model are combined to improve the flood simulation accuracy. First, the hydraulic flow model is calibrated by optimizing the Manning's roughness coefficient that considers spatial and temporal variability. Then, an error correction model were used to correct the systematic errors of the calibrated hydraulic model. The error correction model is developed using Artificial Neural Networks (ANNs) that can estimate the systematic simulation errors of the hydraulic model by considering some state variables as inputs. The input variables are selected using parital mutual information (PMI) technique. It was found that the calibrated hydraulic model can simulate flood water levels with good accuracy. Then, the accuracy of estimated flood levels is improved further by using the error correction model. The method proposed in this study can be used to the flood control and water resources management as it can provide accurate water level eatimation.

• Ecology and Resilient Infrastructure
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• v.9 no.1
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• pp.24-35
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• 2022

For water quality management, it is necessary to continuously improve the forecasting by analyzing the past water quality, and a Data-driven model is emerging as an alternative. Because the Data-driven model is built based on a wide range of data, it is essential to apply the correlation analysis method for the combination of input variables to obtain more reliable results. In this study, the Gamma Test was applied as a preceding step to build a faster and more accurate data-driven water quality prediction model. First, a physical-based model (HSPF, EFDC) was operated to produce daily water quality reflecting the complexity of the watershed according to various hydrological conditions for Paldang Dam. The Gamma Test was performed on the water quality at the water quality prediction site (Paldangdam2) and major rivers flowing into the Paldang Dam, and the method of selecting the optimal input data combination was presented through the analysis results (Gamma, Gradient, Standar Error, V-Ratio). As a result of the study, the selection criteria for a more efficient combination of input data that can save time by omitting trial and error when building a data-driven model are presented.

• Journal of Environmental Science International
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• v.13 no.11
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• pp.993-1000
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• 2004

As an effort to clarify the ecosystem of Osaka Bay, a semi-enclosed coastal area under the influence of stratification, a three-dimensional water quality model with combination of the baroclinic flow model and primitive eco-system model was constructed. The proposed model succeeded in simulating the time-depending flow and density structure and the baroclinic residual currents in Osaka Bay. In present study, we tried to improve the model by taking account of the benthic-pelagic interaction and exchange of nutrients between sea bottom sediments and overlaying water. On vertical structure, the model consists of 13 layers of water and eight layers of sediments. Long-term prediction of water quality was conducted from 1964 to 1985. This period is characterized by rapid water pollution and its decrease by the cutoff reduction of COD and P flowed into Osaka Bay. By combining the sediment model into original model, the numerical model was confirmed to shows more reasonable results in simulating the water quality in Osaka Bay.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1081-1086
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• 2007

This study was performed to investigate the medicinal effects of the herbal combination extracts-2 (HCE-2), consisting of Artemisia capillaris Thunb., Lonicera japonica Thunb., Prunella vulgaris var. lilacina, and Hovenia dulcis Thunb. on the alcohol-induced liver injury in rats. The rats were randomly divided into four groups: normal group (n =6), non-treated control group (n =6), saline-treated group (n =6) and the herbal combination extract (HCE-2)-treated group (n =6). The rats in the alcohol-loaded groups were orally administered with ethanol at a daily dose of 4 g/kg-body weight for 5 weeks. Thirty minutes before the ethanol injection, saline or herbal combination extracts was administered by using a gastrogavage. Blood and liver tissue samples were taken out from the hearts and livers of the rats, respectively, on 15th and 38th days. The activities of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured using an enzyme-linked immunosorbent assay (ELISA). We also investigated the protective effect of the herbal combination extracts by Hematoxylin-Eosin staining on histological sections of rat liver. In this study, the oral administration of the herbal combination extracts significantly reduced the serum levels of AST and ALT, which had been raised by alcohol-induced liver injury. Histological analysis and apparent observation of liver also showed the preventive effect of the herbal combination extracts in a chronic alcohol-induced rat model. Theses results revealed that the herbal combination extracts effectively prevented hepatic damage consequent to the chronic exposure to repetitive administration of ethanol and could be used as a primary resource of a health beverage or herbal medicine, alleviating the alcohol-induced hepatic injury and hangover symptoms.