• Title/Summary/Keyword: Deformed barrel-roll

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FE-based On-Line Model for the Prediction of Radial Displacements in Roll Deformation (롤변형에서의 반경방향 변위 예측 온라인 모델)

  • Cho, J.B.;Hwang, S.M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.04a
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    • pp.19-22
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    • 2009
  • It is essential to predict the deformed roll profile for the prediction of the strip profile in rolling process. The work roll of the Sendzimir mill has a small diameter in comparison to a barrel length, so that it is well deformed by the rolling pressure. Also it has a complex roll system, so it is difficult to analyze the roll deflection. In this paper, 3D finite element method is used for the analysis of the roll deflection of the Sendzimir due to the contact between rolls. But it takes much time to get the results, so that the on-line model to evaluate the radial deformation of a roll is developed on the basis of the finite element method.

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3-D Optimal Evasion of Air-to-Surface Missiles against Proportionally Navigated Defense Missiles

  • Cho, Sung-Bong;Ryoo, Chang-Kyung;Tahk, Min-Jea
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.514-518
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    • 2003
  • In this paper, we investigate three dimensional optimal evasive maneuver patterns for air-to-surface attack missiles against proportionally navigated anti-air defense missiles. Interception error of the defense missile can be generated by evasive maneuver of the attack missile during the time of flight for which the defense missile intercepts the attack missile. Time varying weighted sum of the inverse of these interception errors forms a performance index to be minimized. Direct parameter optimization technique using CFSQP is adopted to get the attack missile's optimal evasive maneuver patterns according to parameter changes of both the attack missile and the defense missile such as maneuver limit and time constant of autopilot approximated by the 1st order lag system. The overall shape of resultant optimal evasive maneuver to enhance the survivability of air-to-surface missiles against proportionally navigated anti-air missiles is a kind of deformed barrel roll.

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Performance Comparison of 3-D Optimal Evasion against PN Guided Defense Missiles Using SQP and CEALM Optimization Methods (SQP와 CEALM 최적화 기법에 의한 대공 방어 유도탄에 대한 3차원 최적 회피 성능 비교)

  • Cho, Sung-Bong;Ryoo, Chang-Kyung;Tahk, Min-Jea
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.3
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    • pp.272-281
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    • 2009
  • In this paper, three-dimensional optimal evasive maneuver patterns for air-to-surface attack missiles against proportionally navigated anti-air defense missiles were investigated. An interception error of the defense missile is produced by an evasive maneuver of the attack missile. It is assumed that the defense missiles are continuously launched during the flight of attack missile. The performance index to be minimized is then defined as the negative square integral of the interception errors. The direct parameter optimization technique based on SQP and a co-evolution method based on the augmented Lagrangian formulation are adopted to get the attack missile's optimal evasive maneuver patterns. The overall shape of the resultant optimal evasive maneuver is represented as a deformed barrel-roll.