• 제목/요약/키워드: Optimal Re-entry Time

검색결과 3건 처리시간 0.014초

One optimization on the flight trajectories of re-entry vehicle

  • Takano, Hiroyuki;Nakamura, Kazuki;Baba, Yoriaki
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.307-310
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    • 1996
  • In this paper, we deal with some numerical analyses of a re-entry vehicle in a 2-dimensional plane as an optimal control problem. To reduce the dynamic load, the heat load and the oscillation in the trajectory, we researched the trajectories in which the load factor or the rate of flight path angle was minimized during re-entry. In addition to that, taking advantage of the monotonous subarc method and the folded time-axis method, we tried to find the heat-less and load-less trajectory with combinations of some sectional functionals so that we can achieve more comfortability.

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When Do the Unemployed Jump in the Workforce?

  • Lee, Hyun-Tak;Jang, Bong-Gyu;Park, Seyoung
    • Management Science and Financial Engineering
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    • 제19권2호
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    • pp.43-47
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    • 2013
  • This paper studies an optimal consumption and portfolio choice problem for unemployed people who have an option to work. Our problem is to find optimal consumption, risky investment, and workforce re-entry strategies for the unemployed. We find a closed form of the critical wealth level to re-enter the workforce. We show that the unemployed with a higher disutility of labor or a larger relative risk aversion are more reluctant to re-enter the workforce.

시간지연기법을 적용한 재사용발사체 유도제어 시뮬레이션 (Simulation of Time-Delay Based Path-Tracking Control of Reusable Launch Vehicle)

  • 조우성;이형진;이열;고상호
    • 한국항공우주학회지
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    • 제49권8호
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    • pp.627-636
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    • 2021
  • 본 논문에서는 재사용발사체 유도제어에 관한 연구를 다루었다. 이를 위하여 6자유도의 재사용발사체 운동방정식 모델링을 수행하였으며, 이를 이용하여 최적 재진입경로를 생성 및 해당 경로를 추종하는 유도제어 시뮬레이션을 수행하였다. 유도제어기 설계를 위하여 모델링 불확실성, 외란 및 고장에 강한 시간지연기법을 적용한 자세제어기와 비선형 유도법칙을 이용하였다. 고전적인 PD 제어기를 적용한 유도제어 시뮬레이션을 수행하여 시간지연기법을 적용한 재사용발사체의 유도제어 시뮬레이션과 비교 검증하였다.