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트렌치 게이트 IGBT 에서의 공정 및 설계 파라미터에 따른 항복 전압 특성에 관한 연구
신호현,이한신,성만영,Shin, Ho-Hyun,Lee, Han-Sin,Sung, Man-Young 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.5
In this paper, effects of the trench angle($\theta$) on the breakdown voltage according to the process parameters of p-base region and doping concentrations of n-drift region in a Trench Gate IGBT (TIGBT) device were analyzed by computer simulation. Processes parameters used by variables are diffusion temperature, implant dose of p-base region and doping concentration of n-drift region, and aspects of breakdown voltage change with change of each parameter were examined. As diffusion temperature of the p-base region increases, depth of the p-base region increases and effect of the diffusion temperature on the breakdown voltage is very low in the case of small trench angle($45\;^{\circ}$) but that is increases 134.8 % in the case of high trench angle($90\;^{\circ}$). Moreover, as implant dose of the p-base region increases, doping concentration of the p-base region increases and effect of the implant dose on the breakdown voltage is very low in the case of small trench angle($45\;^{\circ}$) but that is increases 232.1 % in the case of high trench angle($90\;^{\circ}$). These phenomenons is why electric field concentrated in the trench is distributed to the p-base region as the diffusion temperature and implant dose of the p-base increase. However, effect of the doping concentration variation in the n-drift region on the breakdown voltage varies just 9.3 % as trench angle increases from $45\;^{\circ}$ to $90\;^{\circ}$. This is why magnitude of electric field concentrated in the trench changes, but direction of that doesn't change. In this paper, respective reasons were analyzed through the electric field concentration analysis by computer simulation.
Design of a Flight Envelope Protection System Using a Dynamic Trim Algorithm
신호현,이상현,김유단,김응태,성기정 한국항공우주학회 2011 International Journal of Aeronautical and Space Sc Vol.12 No.3
Most large commercial aircrafts and high performance military aircrafts use fly-by-wire (FBW) or fly-by-light systems to improve their controllability, comfort, and safety. A flight envelope protection technique is used with flight control systems utilizing the FBW technique. Such flight envelope protection systems prevent these aircraft from exceeding the structural/aerodynamic limits and control their surface limits. This is accomplished by predicting the values of the future state variables and adaptively compensating the control action. In this study, the conventional dynamic trim algorithm of the flight envelope protection is modified to increase the method accuracy and to handle cases with multiple variables. Numerical simulation is also performed to verify the performance of the proposed method.
신호현(Hohyun Shin),이상현(Sanghyun Lee),김유단(Youdan Kim),김응태(Eung Tae Kim),성기정(Ki Jung Seong),최형식(Hyoung Sik Choi) 한국항공우주학회 2010 韓國航空宇宙學會誌 Vol.38 No.4
최근 개발된 항공기는 대부분 디지털 Fly-By-Wire(FBW) 혹은 광신호를 사용하는 Fly-By-Light(FBL) 시스템을 사용하고 있다. 이러한 시스템들은 조종사의 직접 조종으로는 불가능하거나 어려운 복잡한 임무의 수행, 비행범위 확장, 신뢰성 향상 등의 장점을 가지고 있다. FBW 기술을 적용한 비행제어기술이 발전됨에 따라 운항 시 안정성 확보 및 보다 효율적인 임무수행을 위해 비행영역(Flight Envelope) 보호의 개념이 항공기 설계에 있어 중요한 문제로 부각되고 있다. 본 논문에서는 dynamic trim 알고리즘, peak response estimation, 제어이득 스케쥴링 등의 방법을 이용해서 항공기의 비행영역 보호를 수행하고, 각 방법의 성능을 비교하여 최적의 제어기를 설계하는 연구를 수행하였다. Recently developed aircrafts use Fly-By-Wire(FBW) or Fly-By-Light(FBL) system. These systems have some merits; they can perform very complicated missions, they can expand the flight region and improve the reliability of the aircrafts. With the development of flight control systems that use FBW technique, flight envelope protection concept is introduced to guarantee reliability of the aircraft and improve the efficiency of mission achievement. In this study, flight envelope protection system is designed using a dynamic trim algorithm, a peak response estimation, and a gain scheduling technique. The performance of these methods are compared by performing numerical simulation.
SAR위성의 영상획득 시나리오 모델링 및 임무설계 알고리즘 성능검증
신호현(Hohyun Shin),김종필(Jongpil Kim) 한국항공우주학회 2019 韓國航空宇宙學會誌 Vol.47 No.8
현대 사회에서 인공위성은 통신, 영상 등의 분야에서 널리 이용되고 있다. 이 중에서도 인공위성을 통해 획득한 영상은 넓은 지역에 대한 다양한 정보를 담고 있어 농업, 자원개발 및 활용, 군사적 목적 등으로 활용되고 있다. 인공위성의 특성상 영상을 획득할 수 있는 시간이 매우 제한적이므로 주어진 시간 내에 최대한 효율적인 영상획득을 수행하는 것이 중요하다. 이를 위해서 본 연구에서는 인공위성이 영상을 획득하는 데 소요되는 시간 및 자세 기동에 대한 모델링을 수행하고 이를 바탕으로 휴리스틱 평가함수를 이용한 임무설계 알고리즘을 제안하고 수치 시뮬레이션을 통하여 해당 알고리즘의 성능을 검증하였다. Today, satellites are widely used in many fields like communication and image recoding. The image acquired by satellites contains variety information of wide region. Therefore, they are used for agriculture, resource exploitation and management, and military purpose. The satellite is required to acquire images effectively in a given time period. Because the period that satellites can acquire images is very restrictive. In this study, the modeling of processing time and attitude maneuvering for satellite image acquisition is performed. From this modeling, mission planning algorithm using heuristic evaluation function is suggested and performance of the proposed algorithm is verified by numerical simulation.