http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
박찬덕 ( Park Chan Deok ),박병수 ( Park Byung Soo ) 한국구조물진단유지관리공학회 2018 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.22 No.1
This study is a case of construction after bridge demolition due to the aging of bridges operating the railway. Due to the influence of the pier vibration on the railway, the influence of the railway line, the construction period, etc., the P.B.S technique was applied to the coping pile foundation. It was completed in 5 days per 1 bridge pier by the PBS method. Since it is constructed in the dry season (from October to April) without vibration and noise, it can be installed safely on the rail rail of the pier of the bridge .
황인영,박찬덕,박상영 한국우주과학회 2013 Journal of Astronomy and Space Sciences Vol.30 No.1
A collision-free formation reconfiguration trajectory subject to the linearized Hill’s dynamics of relative motion is analytically developed by extending an algorithm for gravity-free space. Based on the initial solution without collision avoidance constraints, the final solution to minimize the designated performance index and avoid collision is found, based on a gradient method. Simple simulations confirm that satellites reconfigure their positions along the safe trajectories, while trying to spend minimum energies. The algorithm is applicable to wide range of formation flying under the Hill’s dynamics.
김경하,박찬덕,박상영 한국우주과학회 2015 Journal of Astronomy and Space Sciences Vol.32 No.4
This work presents fuel-optimal altitude maintenance of Low-Earth-Orbit (LEO) spacecrafts experiencing non-negligible air drag and J2 perturbation. A pseudospectral (direct) method is first applied to roughly estimate an optimal fuel consumption strategy, which is employed as an initial guess to precisely determine itself. Based on the physical specifications of KOrea Multi-Purpose SATellite-2 (KOMPSAT-2), a Korean artificial satellite, numerical simulations show that a satellite ascends with full thrust at the early stage of the maneuver period and then descends with null thrust. While the thrust profile is presumably bang-off, it is difficult to precisely determine the switching time by using a pseudospectral method only. This is expected, since the optimal switching epoch does not coincide with one of the collocation points prescribed by the pseudospectral method, in general. As an attempt to precisely determine the switching time and the associated optimal thrust history, a shooting (indirect) method is then employed with the initial guess being obtained through the pseudospectral method. This hybrid process allows the determination of the optimal fuel consumption for LEO spacecrafts and their thrust profiles efficiently and precisely.
중력장내에서 충돌방지를 고려한 편대비행 위성의 준최적 재배치
황인영,박상영,박찬덕 한국항공우주학회 2012 한국항공우주학회 학술발표회 논문집 Vol.2012 No.11
논문에서는 Hill 운동방정식을 적용한 위성의 충돌 방지 준 에너지 최적 재배치 경로를 구하는 연구를 진행하였다. 이를 위해 Hill 운동방정식을 적용시킬 수 있는 방안을 제시하고, 기존에 심우주 환경에서 충돌 방지 경로를 구하는 알고리즘을 확장시켜 Hill 운동방정식을 적용시키는 알고리즘을 개발하였다. Hill 운동방정식을 따르며 초기 조건과 최종 조건이 있는 최적 제어 문제의 해석 해를 이용하여 성능지수와 제한조건을 재정의하고 이미 알려진 충돌 방지 알고리즘에 적용하였다. 간단한 시뮬레이션을 수행하고 모든 충돌이 방지된 궤도를 확인하였다. This paper presents a technique to generate collision avoidance trajectories of sub-energy optimal satellites formation reconfiguration based on the circular Hill dynamics. The performance index and collision avoidance constraints are re-organized by using analytic solution of energy optimal problem with initial and final constraint under the Hill dynamics. The a collision avoidance algorithm under deep space is extended to apply the satellite formation reconfiguration problem under a central-body gravitation. An example simulation shows that the extended algorithm has a good performance for collision avoidance reconfiguration under gravitational forces.