• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.215-226
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• 2018

The purpose of this study is to improve the accuracy of the urban runoff and drainage network analysis by using the observed water level in the drainage network. To do this, sensitivity analysis for major parameters of SWMM (Storm Water Management Model) was performed and parameters were calibrated. The sensitivity of the parameters was the order of the roughness of the conduit, the roughness of the impervious area, the width of the watershed, and the roughness of the pervious area. Six types of scenarios were set up according to the number and types of parameter considering four parameters with high sensitivity. These scenarios were applied to the Seocho-3/4/5, Yeoksam, and Nonhyun drainage basins, where the serious flood damage occurred due to the heavy rain on 21 July, 2013. Parameter optimization analysis based on PEST (Parameter ESTimation) model for each scenario was performed by comparing observed water level in the conduits. By analyzing the accuracy of each scenario, more improved simulation results could be obtained, that is, the maximum RMSE (Root Mean Square Error) could be reduced by 2.41cm and the maximum peak error by 13.7%. The results of this study will be helpful to analyze volume of the manhole surcharge and forecast the inundation area more accurately.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.349-354
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• 1983

A study on the color changes of fish meat during drying was conducted using fishes with different lipid contents, such as Alaska pollack as lean fish, conger eel as white fleshed fatty fish, and sardine as dark fleshed fatty fish. The fish meat was dried in a forced air dryer for 20 hours at 40, 55 and $70^{\circ}C$, The air velocity was 0.4 m/sec and the relative humidity of air was controlled to a constant value in the range of 10 to $50\%$. The color changes were evaluated with the brown color densities developed by lipid oxidation and Maillard reaction. The predominant reaction for the brown color developed during drying was lipid oxidation, The more the lipid content of fish and the higher the drying temperature were, the more violent the oxidative reaction of Lipid was. The rate of lipid oxidation during drying at 40 and $55^{\circ}C$ was affected by the relative humidity of air and was the slowest around $30\%$. But no remarkable influence of relative humidity on the rate of lipid oxidation could be confirmed during drying at $70^{\circ}C$. It seemed that the rate of lipid oxidation at higher temperature was more sensitive to the temperature than the relative humidity of air. Maillard reaction showed not so significant influence on the color changes of fish meat during drying. The rate of reaction was increased with increasing relative humidity of air in the range of 10 to $50\%$.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.167-170
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• 2007

동일한 집단에 속하는 개체를 다른 집단에 속하는 개체로부터 구별할 수 있는 염기의 특징을 해당 집단의 시그너쳐라고 한다. 학습 데이터는 두 집단에 속하는 염기서열들이고, 염기서열에 대한 시그너쳐는 개체를 다른 집단과 구별할 수 있는 위치의 염기들로 구성된 서열이다. 제안한 방법에서는 각 집단에 대해서 위치별로 염기의 발생빈도를 계산하고, 가장 발생빈도가 높은 염기를 결정한 다음, 다른 집단의 대응 위치에서 해당 염기의 빈도를 계산하여, 빈도차이가 지정한 분류임계값 이상이면, 해당 위치의 염기를 시그너쳐를 구성하는 특징으로 간주한다. 시그너쳐를 대한 임의의 염기서열에 대한 부합정도는 시그너쳐에 속하는 염기의 학습집단에서의 상대빈도값을 가중치로 하여 계산한다. 임의의 염기서열이 특정 집단에 속하는지 판단하기 위해서는 해당 집단의 시그너쳐에 대한 부합정도를 계산하게 되는데, 부합정도가 얼마이상이 되어야 해당 집단에 속하는 것으로 간주할지 기준이 되는 임계값을 엄밀도 임계값이라고 한다. 엄밀도 임계값은 학습 데이터 집합에 대해서 주어진 시그너쳐에 대한 엄밀도 임계값이 민감도와 특이도를 최대로 하는 것을 선택한다. 제안한 방법을 구현한 바이오인포매틱스 도구를 개발하여, 한국형 HIV-1 바이러스 시그너쳐 추출에 적용하여 분류특성이 우수한 시그너쳐를 추출할 수 있음을 확인하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.2
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• pp.298-303
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• 2010

robots determine the location of the other robot using wireless sensors. Use it to decide how to move his. And go to any location, will make shape of column and line, circle. In this paper, we discuss problem in circle formation enclosing target which moves. It is method about enclosed invader in circle formation based on mutual localization of swarm robot without infrastructure. Therefore, use trilateration that do not need to know the value of the coordinates of reference points. So, Specify enclosed point for the number of robots base on between the relative position of the robot in the coordinate system. And particle filter is proposed to improve the accuracy of the location.

• Journal of KSNVE
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• v.7 no.2
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• pp.247-254
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• 1997

In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria are usually obtained either by the real vibration exciting test on the equipment or by the analytical calculation. This paper proposes a new method to solve this problem at a time. The permissible vibration level to a precision equipment can be easily obtained by analyzing a process of Frequency Response Function. This paper also demonstrates its effectiveness by applying the proposed method to finding the vibration criteria of a Computer Hard Disk Driver by Impact Test.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.710-710
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• 2012

구형펄스모형(Rectangular Pulse Model)에서 반영하지 못하는 강우의 군집특성을 잘 반영하는 NSRPM(Neyman-Scott Rectangular Pulse Model) 강우생성 모형은 수자원 분야에 널리 쓰이고 있다. 일반적으로 NSRPM의 5개의 매개변수를 추정하는 최적화기법으로 DFP(Davidon-Fletcher-Powell)과 유전자알고리즘(Genetic Algorithm)을 사용하고 있다. 그러나 DFP는 주어진 초기 값에 따라 민감하며 각 반복 단계마다 헤시안행렬(Hessian Matrix)을 계산하여야 하며 추정된 전체의 해가 국지해에 수렴 할 수 있는 단점이 있다. 유전자 알고리즘을 DFP와 다르게 헤시안 행렬을 사용하지 않고 최적화를 할 수 있다는 장점이 있으나 시간이 오래 걸리는 단점이 있다. 이에 본 연구에서는 이러한 단점을 보완, 강화 하기위해서 최적화 기법으로 반복 단계마다 미분계산이 필요하지 않고 빠른 속도로 계산이 가능한 Nelder-Mead 알고리즘 이용하여 NSRPM매개변수를 추정하고 정확도를 비교하였다. 표 1은 각 기법을 이용하여 추정된 매개변수를 이용하여 생성한 강우의 통계특성과 관측된 통계특성의 상대오차를 나타낸 것이다. 괄호 안 숫자는 중첩되지 않는 누적시간을 나타낸다. 상대오차는 다음과 같다(식 1). 분석결과 Nelder-Mead 기법이 1시간의 평균, 공분산과 6시간 분산 등 전체적으로 GA, DFP보다 높은 정확도를 보였다.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.113-116
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• 2007

This is a research for evaluated recycled glass powder to add asphalt concrete filler. To make a comparative study, Mechanical performance of lime stone and slag dust Mixtures was evaluated according to test procedure. Lab. performance tests included marshall stability, indirect tensile strength, resilient modulus and wheel tracking. Water resistance tests were evaluated by marshall strength ratio and tensile strength ratio. In conclusion, Results of mechanical performance showed that recycled glass powder mixtures were equivalent to conventional mixtures. Especially, result of tensile strength ratio tested recycled glass powder mixtures was superior to conventional mixtures.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.254-258
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• 2008

본 연구는 격자기반 운동파 강우유출모형 KIMSTORM(grid-based KIneMatic wave STOrm Runoff Model)의 기능을 개선하고 적용성을 평가하는 것이다. KIMSTORM은 김성준(1998)이 개발한 분포형 강우유출모형으로 포화상태의 지표흐름 및 토양수분상태의 시공간적인 분포를 파악할 수 있다. UNIX C++ 언어로 개발되었으며, GRASS 형태의 ASCII Grid를 입출력하도록 구성되어 있는 모형으로 UNIX 운영체제에서 구동이 가능하다. 그러나 UNIX와 GRASS는 최근에 많이 이용되지 않는 추세로 KIMSTORM 모형을 이용한 홍수유출해석이 적극적으로 활용되는데 주요 제약사항이 되어 왔다. 본 연구에서는 KIMSTORM을 윈도우즈 환경에서 운영될 수 있도록 FORTRAN 90을 이용하여 재개발하였으며 주요개선 사항으로, ESRI ASCII Grid 형태의 GIS(geographic information system) 자료 입력, 물리적 침투모의 방법인 GAML (Green-Ampt and Mein- Larson) 적용, 공간강우 입력가능, 정렬 알고리즘을 이용한 계산속도의 개선, 모형 자료입력 등 전처리 기능개선, 계산결과의 자동평가 및 분포도출력 등 후처리 방식개선으로 요약할 수 있다. 개선된 모형 GAML에 의한 침투방법을 적용하여, 남강댐유역($2,293\;km^2$)의 6개 강우사상을 대상으로 결정계수, Nash & Sutcliffe 모형효율계수, 용적편차, 첨두유량의 상대오차, 첨두시간의 절대오차를 이용하여 적용성을 평가하였으며, 민감도분석결과 초기토양수분조건과 하천조도계수가 가장 큰 민감도를 나타내었다.

• The Korean Journal of Applied Statistics
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• v.26 no.1
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• pp.15-22
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• 2013

In clinical study or epidemic research, the $2{\times}2$ frequency table is useful to present a summary statistic The values of four cells in $2{\times}2$ table use to calculate the effect measures such as risk ratio, relative ris ratio or odds ratio. In this paper, we suggest that the improved visualization method using a radar diagram supported by MS-office Excel from the $2{\times}2$ frequency table is able to understand and draw easily betweendiagnosti measures such as sensitivity, specificity, predictivity, and likelihood ratio. We use some numerical example in order to show the usage of the proposed method.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.3
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• pp.125-131
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• 1997

In order to analyze the feasibility of the drain layer construction method, which is one of the beach protection methods, a hybrid model is constructed by combining the wave model and the seepage flow model. The used wave model is the analytic solution given by Shuto (1972). and the seepage flow model is used by Richards equation which governs the saturated-unsaturated flow in the porous media. It is concluded by the sensitivity analysis of the hybrid model that the most sensitive parameter in the flow field within the beach is the saturated hydraulic conductivity. The developed hybrid model will be efficiently used in the analysis of the parameter when the drain layers are constructed in the beach, if the field datas are obtained more.