• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.305-306
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• 2006

Developed in this study is a nonlinear Ekman pumping model to be used in simulating the rotating flows with quasi-three-dimensional Navier-Stokes equations. In this model, the Ekman pumping velocity is given from the solution of the Ekman boundary-layer equations for the region adjacent to the bottom wall of the flow domain; the boundary-layer equations are solved in the momentum-integral form. The developed model is then applied to rotating flows in a rectangular container receiving a time-periodic forcing. By comparing our results with the DNS and experimental data we have validated the developed model. We also compared our results with those given from the classical Ekman pumping model. It was found that our model can predict tile rotating flows more precisely than the classical linear model.

• 대한기계학회논문집B
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• 제30권6호
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• pp.568-577
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• 2006

Developed in this study is a nonlinear Ekman pumping model to be used in simulating the rotating flows with quasi-three-dimensional Navier-Stokes equations. In this model, the Ekman pumping velocity is given from the solution of the Ekman boundary-layer equations for the region adjacent to the bottom wall of the flow domain; the boundary-layer equations are solved in the momentum-integral form. The developed model is then applied to rotating flows in a rectangular container receiving a time-periodic forcing. By comparing our results with the DNS and experimental data we have validated the developed model. We also compared our results with those given from the classical Ekman pumping model. It was found that our model can predict the rotating flows more precisely than the classical linear model.

• 상하수도학회지
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• 제31권5호
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• pp.421-430
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• 2017

In this study, a model was developed to predict for Disinfection By-Products (DBPs) generated in water supply networks and consumer premises, before and after the introduction of advanced water purification facilities. Based on two-way ANOVA, which was carried out to statistically verify the water quality difference in the water supply network according to introduce the advanced water treatment process. The water quality before and after advanced water purification was shown to have a statistically significant difference. A multiple regression model was developed to predict the concentration of DBPs in consumer premises before and after the introduction of advanced water purification facilities. The prediction model developed for the concentration of DBPs accurately simulated the actual measurements, as its coefficients of correlation with the actual measurements were all 0.88 or higher. In addition, the prediction for the period not used in the model development to verify the developed model also showed coefficients of correlation with the actual measurements of 0.96 or higher. As the prediction model developed in this study has an advantage in that the variables that compose the model are relatively simple when compared with those of models developed in previous studies, it is considered highly usable for further study and field application. The methodology proposed in this study and the study findings can be used to meet the level of consumer requirement related to DBPs and to analyze and set the service level when establishing a master plan for development of water supply, and a water supply facility asset management plan.

• Agricultural and Biosystems Engineering
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• 제4권1호
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• pp.34-38
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• 2003

A mathematical model was developed for estimating the mechanical interrelation between characteristics of soil and main design factors of a tracked vehicle, and predicting the tractive performance of the tracked vehicle. Based on the mathematical model, a computer simulation program (TPPMTV) was developed in the study. The model considered the continuous change in tension for the whole track of a tracked vehicle, the analysis of shape and tension of the track segment between sprocket and first roadwheel, and the side thrust on both sides of grouser by the active earth pressure theory in predicting the tractive performance of a tracked vehicle. Also, the model contained not only sinkage depth of the track but the pressure distribution under the track in analyzing the side thrust. The effectiveness of the developed model was verified by performing the draw bar pull tests with a tracked vehicle reconstructed for test in loam soil with moisture content of 18.92％. The predicted drawbar pulls by the model were well matched to the measured ones. Such results implied that the model developed in the study could estimate the drawbar pulls well at various soil conditions, and would be very useful as a simulation tool for designing a tracked vehicle and predicting its tractive performance.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1065-1078
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• 2009

The shear strength has been managed as an important factor in soil mechanics. The shear strength estimation model was developed to evaluate the shear strength using only a few soil properties by the linear regression analysis model which is one of the statistical methods. The shear strength is divided into two part; one is the internal friction angle ($\Phi$) and the other is the cohesion (c). Therefore, some valid soil factors among the results of soil tests are selected through the correlation analysis using SPSS and then the model are formulated by the linear regression analysis based on the relationship between factors. Also, the developed model is compared with the result of direct shear test to prove the rationality of model. As the results of analysis about relationship between soil properties and shear strength, the internal friction angle is highly influenced by the void ratio and the dry unit weight and the cohesion is mainly influenced by the void ratio, the dry unit weight and the plastic index. Meanwhile, the shear strength estimated by the developed model is similar with that of the direct shear test. Therefore, the developed model may be used to estimate the shear strength of soils in the same condition of study area.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.362-367
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• 2013

Vehicle CAE models for NVH predictions are largely developed in two schemes. One is FE models generally used for below 200 Hz problems such as booming noise, and the other is SEA models for high frequencies of more than 1 kHz, representatively related to sound packages. HMC has tried to develop a CAE model for 200-1000 Hz, so-called mid-frequency region, and this paper is one of the corresponding results. The CAE model is developed based on an FE model, and then FE elements at some areas are substituted with SEA elements to reduce DOFs. SEA panels are described by modal density, radiation efficiency, stiffness and damping characteristics that are found from some numerical assessments. Sound packages are modeled similarly as a conventional SEA model. The CAE model developed in this manner, the hybrid model, was compared to experimental results. Predicted pressure and vibrational velo city generally show a good agreement. The developed CAE model and related technology are successfully being used in vehicle development process.

• 한국시뮬레이션학회논문지
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• 제20권4호
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• pp.49-58
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• 2011

국산 개발 분산 제어시스템의 발전 설비에의 적용을 위해서는 시뮬레이터를 이용한 제어 시스템의 기능 및 신뢰성 등의 검증이 선행되어야만 한다. 본 논문에서는 제어 시스템 검증용 시뮬레이터를 개발하는데 있어서, 제어 모델 중 발전소 기동 초기에 보일러 압력을 조절하고, 정상 운전 중 보일러의 과대 압력 상승을 방지하기 위해 보일러에서 발생한 증기를 복수기로 방출하는 터빈 바이패스 계통의 제어 모델을 개발하였다. 제어 모델 개발을 위해, 통합 시뮬레이션 개발 환경에서 활용가능한 제어 로직 구현 툴을 개발하였다. 또한 개발한 툴의 기능은 개별 기능 블럭의 설계 사양에 기반한 시뮬레이션에 의해 검증을 하였으며, 개발한 툴을 이용하여 고압 터빈 바이패스 계통의 압력 제어 로직을 구현하였다. 500 MW급 표준 석탄화력 발전소 공정 모델과 보일러 제어 모델, 터빈 제어 모델 등 타 계통의 제어 모델과의 연계를 통한 통합 시뮬레이션을 통해 개발한 제어 모델의 효용성을 확인하였다.

• 한국음향학회지
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• 제16권4호
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• pp.29-34
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• 1997

원거리에서 수동소나에 의한 탐지거리를 예측하기 위해서는 소나방정식이 이용된다. 본 연구에서는 거리와 깊이함수의 신호이득 및 탐지확률을 구한 후 이를 거리로 적분하여 거리의존 해양환경에서 탐지거리를 계산하는 탐지거리 예측모델을 개발하였다. 개발된 모델은 기존에 발표된 거리독립 해양환경에서의 결과와 비교하여 검증하였고, 이를 바탕으로 거리의존 해양환경에서 수동소나에 의한 표적탐지에 큰 영향을 주는 난수성 소용돌이 해양환경에 확장 적용하여 표적의 탐지거리를 예측하였으며, 그 결과에 대하여 소개한다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1990년도 춘계공동학술대회논문집; 한국과학기술원; 28 Apr. 1990
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• pp.100-110
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• 1990

An optimal raw mix model in stainless steel making is developed. The key raw materials in stainless steel making are stainless steel scrap, steel scrap, and alloy materials like Fe-Ni, Fe-Cr. Among those raw materials, the alloy metals are very expensive as well as rapidly price-changing items. Consequently, it is very important to develop an minimal cost raw mix scheme while the produced stainless steel satisfies the required specification in it's composition. The linear programming model is employed to determine the minimal cost raw mix scheme. Compared with the method being used, the developed linear programming model gives much faster and better solution (lower cost raw mix plan). Together with the linear programming model, the database is also developed, which includes the following: 1) data for raw materials, such as compositions, costs, densities, available inventory levels, and so on, 2) the required specifications process. The developed optimal raw mix model will be implemented in VAX computer.

• 한국농공학회지
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• 제42권
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• pp.17-23
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• 2000

A decision support system for determining reservoir capacity, named as KORESIDSS (KOwaco's REservoir SIzing Decision Support System), was developed. The system is composed of three subsystems; a database/information subsystem, a model subsystem, and an output subsystem. This system is operated using MS-Windows with a GUI (Graphic User Interface) system developed using Visual Basic 5.0. As a continuous runoff model, the DAWAST model (DAily WAtershed STreamflow model) developed by Noh(1991) was and its analysis module was developed. This system was applied to a newly-planned dam, the Cheongyan Dam, Which will be located in Cheongyang-Gun, Chungcheongnam-Do and it was proved to be applicable in determining reservoir storage.