http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
각운동량 부피에 근거한 CMG 특이점 영운동 회피 제어기법
이봉운(Bong-Un Lee),오화석(Hwa-Suk Oh),이승우(Seung-Wu Rhee),이선호(Seon-Ho Lee) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
The geometric singularity problem is one of principal difficulty when using single-gimbal control moment gyros as spacecraft attitude control devices. To overcome singularity, a new steering logic is suggested which uses null motion based on the angular momentum envelope. The suggested steering law presented is the reduced dimensional singularity avoidance steering law, which makes use of reduced dimensional forms in generating null motions. This suggested steering law has been generated gimbal rates for null motions, and verified to work well with simulations around a singular point.
김창욱,이봉운 외 1인 空軍士官學校 2000 論文集 Vol.45 No.-
This paper deals with all navigation systems. The characteristics of radionavigation system and inertial navigation system are analyzed. Traditional navigation systems, for example, VOR, DME, TACAN, LOLAN-C, ILS, MLS are briefly surveyed. INS is self-contained system but INS erors are Increased with time. GPS satellite navigation system provides accurate position, velocity and time information anywhere in the world but GPS could not provide accurate information of position due to outages of GPS satellite reception, severe vehicle dynamics and interference. GPS/INS has many benefits because shortage of INS and GPS are compensated. CNS/ATM which is consisted of the satellite navigation system and the satellite communication system is studied. It will be a future civil navigation system. Last, a future military air navigation system Is analyzed and proposed.
심병효,구창설,이봉운 한국군사과학기술학회 2000 한국군사과학기술학회지 Vol.3 No.1
Turbo codes are the most exciting and potentially important development in coding theory in recent years. They were introduced in 1993 by Berrou, Glavieux and $Thitimajshima,({(1)}$ and claimed to achieve near Shannon-limit error correction performance with relatively simple component codes and large interleavers. A required Eb/N0 of 0.7㏈ was reported for BER of $10^{-5}$ and code rate of $l/2.^{(1)}$ However, to implement the turbo code system, there are various important details that are necessary to reproduce these results such as AGC gain control, optimal wordlength determination, and metric rescaling. Further, the memory required to implement MAP-based turbo decoder is relatively considerable. In this paper, we confirmed the accuracy of these claims by computer simulation considering these points, and presented a optimal wordlength for Turbo code design. First, based on the analysis and simulation of the turbo decoder, we determined an optimal wordlength of Turbo decoder. Second, we suggested the MAP decoding algorithm based on sliding-window method which reduces the system memory significantly. By computer simulation, we could demonstrate that the suggested fixed-point Turbo decoder operates well with negligible performance loss.