• 제어로봇시스템학회논문지
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• 제7권5호
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• pp.407-414
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• 2001

In this paper, we present a decentralized robust adaptive fuzzy controller for the transient stability and voltage regulation of a multimachine power system under a sudden fault. Power systems have uncertain dynamics due to various effects such a lightning, severe storms and equipment failure in addition to interconnections between generators. Hence a robust controller to deal with these uncertainties in needed. The fuzzy systems are adapted using a Lyapunov-based design and the stability of each closed-loop system is guaranteed. Simulation results show that satisfactory performance is achieved by proposed controller.

• 물과 미래
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• 제9권1호
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• pp.47-54
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• 1976

The research are intend to establish the design criteria for slopy upland reclamation, with protecting the loss of top-soil, Recently undertaken reclamation works for developing the slopy upland of 310,000 ha. have faced to the vagueness of their deign criteria. One of the most influencing factors to cause the soil erosion depends basically upon the kinematic energy of rainfall, which is developed by the rainfall intensity. Their relationship between the rainfall and its kinematic energy is expressed as EK=916+ 331 log I. Consequently, the study was carried out through analyzing each intensity of the independant rainfall through out the 14 rainfall stations. About 10,000 single storms self recording chart of more than 10mm of rainfall amout were collected and analyzed by computer. The results of research show their kinematic energy for the 14 stations, and will be available for the establishment of the design oriteria.

• 한국환경과학회지
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• 제24권4호
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• pp.383-391
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• 2015

As occurrence of gradually increasing extreme temperature events in Jeju Island, a hybrid downscaling technique that simultaneously applies by dynamical method and statistical method has implemented on design rainfall in order to reduce flood damages from severe storms and typhoons.As a result of computation, Case 1 shows a strong tendency to excessively compute rainfall, which is continuously increasing. While Case 2 showed similar trend as Case 1, low design rainfall has computed by rainfall in A1B scenario. Based on the design rainfall computation method mainly used in Preventive Disaster System through Pre-disaster Effect Examination System and Basic Plan for River of Jeju Island which are considering climatic change for selecting 50-year and 100-year frequencies. Case 3 selecting for Jeju rain gage station and Case 1 for Seogwipo rain gage station. The results were different for each rain gage station because of difference in rainfall characteristics according to recent climatic change, and the risk of currently known design rainfall can be increased in near future.

• 물과 미래
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• 제14권4호
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• pp.13-18
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• 1981

강우량의 시간분포 특성에 관한 강우상태 분석은 소유역의 계획홍수량을 결정한다거나 도시지역의 배수망 설계를 위한 설계유량 산정을 위하여 대단히 중요하다. 서울 지역의 과거 기록치로부터 총강우량이 20mm 이상 되는 약 400개의 호우자료를 이용하여 5분간격 강우의 시간분포를 해석하였다. 총강우량에 대한 백분율을 총강우시간에 대한 백분율과 연관시키고 획득된 자료를 강우 최대치가 발생되는 위치 따라 4개의 그룹으로 분류 분석하여 그 결과를 제시하였다. 또한 강우와 강우간의 변화성을 정량적으로 나타내기 위하여 시간분포 특성을 빈도 확률에 따라 분석하였다. 분석결과로 얻어진 강우의 시간분포 관계는 설계유량 수문곡선 결정에 사용되는 설계강우의 우량주상도를 얻는데 사용될 뿐만 아니라 주어진 유역에서의 강우형상을 파악하는데 적용될 수 있다. 또한 수문해석 문제를 위한 강우의 모델을 형성할 수 있으며 공간적 분포 이외의 강우특성 및 매개변수 등과 같은 자료와 연관시킬 수 있다. 분석결과 제2구간 강우의 빈도가 가장 높았으며 제4구간 강우의 빈도가 가장 낮았다. 이와 같은 분석 결과인 시간분포의 특성을 누가 강우시간 백분율과 누가 강우량 백분율의 항으로써 확률별로 표시하였으며 각 구간별 강우의 시간분포 양상 및 그에 따른 우량주상도를 도표화하였다.

• Wind and Structures
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• 제17권5호
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• pp.495-513
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• 2013

Thin, high-strength steel roof cladding is widely used in residential and industrial low-rise buildings and is susceptible to failure during severe wind storms such as cyclones. Current cladding design is heavily reliant on experimental testing for the determination of roof cladding performance. Further study is necessary to evolve current design standards, and numerical modelling of roof cladding can provide an efficient and cost effective means of studying the response of cladding in great detail. This paper details the development of a numerical model that can simulate the static response of corrugated roof cladding. Finite element analysis (FEA) was utilised to determine the response of corrugated cladding subject to a static wind pressure, which included the anisotropic material properties and strain-hardening characteristics of the thin steel roof cladding. The model was then validated by comparing the numerical data with corresponding experimental test results. Based on this comparison, the model was found to successfully predict the fastener reaction, deflection and the characteristics in deformed shape of the cladding. The validated numerical model was then used to predict the response of the cladding subject to a design cyclone pressure trace, excluding fatigue effects, to demonstrate the potential of the model to investigate more complicated loading circumstances.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.197-202
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• 2002

The most common failure of breakwater comes from impact wave pressure generated by intense storms. This impact pressure is 10 folds greater than the pressure generated by normal waves. Therefore, the precise knowledge of magnitude of impact wave pressure applied on breakwater and its structural response is crucial for the economical and safe design. However, presently, a precise analysis of breakwater is restricted by insufficient and incorrect consideration of the effect of soil-structure Interaction. 3 major research areas included in this study are (1) theoretical analysis of impact wave pressure, (2) selection of breakwater structure model (3) soil-structure interaction analysis using limit analysis computer program. Based on this analysis, predicted response of concrete breakwater and probable failure location under wave impact pressure are determined.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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• pp.615-617
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• 1999

In this paper, we present a decentralized robust adaptive fuzzy controller for the transient stability and voltage regulation of a multimachine power system under a sudden fault. Power systems have uncertain dynamics due to various effects such as lightning, severe storms and equipment failure in addition to interconnections between generators. Hence a robust controller to deal with these uncertainties is needed. Simulation results show that satisfactory performance is achieved by the proposed controller.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.604-609
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• 2004

일반적으로 설계호우(확률강우량, PMP 등)는 유역중심에서의 추정되고, 이 값을 유역의 평균강우량으로 이용한다. 그러나, 실제호우는 유역의 형상에 대해 지속기간 동안 균일하게 발생하지 않으려, 이러한 현상을 분석에 적절히 고려하기 위해서 호우의 공간분포에 대한 분석이 필요하다. 또한 유역면적이 크고, 소유역으로 분할된 중${\cdot}$대규모 유역조차도 균일한 설계호우 값을 적용함으로써 평균강우량 및 출력 값을 과대하게 산정할 수 있다. 따라서 본 연구에서는 설계호우의 공간분포를 기왕의 실제호우로부터 가상호우의 형태를 가정하였으며, 이 가상호우의 형태에 따라 설계호우를 대상유역에 공간분포시켜 평균강우량을 재산정하는 절차를 예를 들어 상세히 기술하였다.

• International Journal of Aerospace System Engineering
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• 제2권1호
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• pp.31-37
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• 2015

Passenger plane flying motion graphics is very important for route, control of the flight altitude and passenger safety. For all that, it is quite useful for route away from the disruptive influences such as vibrations caused by storms or turbulence during the flight and in processes such as re-arrest of the specified route. Therefore, the response time against the adverse effects of the shape and the system is so necessary for both safety and comfort. In this study motion and route graphics were obtained under the control of an airliner C # interface with the program. In this way, graphics were obtained in solving the equations of motion in short time and design time was shortened.

• Wind and Structures
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• 제16권4호
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• pp.355-372
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• 2013

The Gringorten estimator has been extensively used in extreme value analysis of wind speed records to obtain unbiased estimates of design wind speeds. This paper reviews the derivation of the Gringorten estimator for the mean plotting position of extremes drawn from parents of the exponential type and demonstrates how it eliminates most of the bias caused by the classical Weibull estimator. It is shown that the coefficients in the Gringorten estimator are the asymptotic values for infinite sample sizes, whereas the estimator is most often used for small sample sizes. The principles used by Gringorten are used to derive a new Consistent Linear Unbiased Estimator (CLUE) for the mean plotting positions for the Fisher Tippett Type 1, Exponential and Weibull distributions and for the associated standard deviations. Analytical and Bootstrap methods are used to calibrate the bias error in each of the estimators and to show that the CLUE are accurate to better than 1%.