• Title/Summary/Keyword: Optimal method

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State feedback optimal control of large-scale discrete-time systems with time-delays (시간지연이 있는 대규모 이산시간 시스템의 상태궤환 최적제어)

  • 김경연;전기준
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.219-224
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    • 1988
  • A decentralised computational procedure is proposed for the optimal feedback gain matrix of large-scale discrete-time systems with time-delays. The constant feedback gain matrix is computed from the optimal state and input trajectries obtained hierarchically by the interaction prediction method. All the calculation in this approach are done off-line. The resulting gains are optimal for all the initial conditions. The interaction prediction method is applied to time-delay large-scale systems with general structures by extending the dimensions of coupling matices. A numerical exampie illustrates the algorithm.

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Development of Die Design System for Turbine Blade Forging (터빈 블레이드의 형단조 금형설계 시스템 개발)

  • 조종래
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.77-81
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    • 1999
  • The predictions of metal flow forging load optimal die angle and preform size are not so easy in turbine blade forging. First of all the quality of final product is influenced by side force which is one of the significant factors. in this study slab method is applied to determine optimal die angle minimizing side force and the position of preform Finally drawing of die design is obtained in optimal die angle with developing tool that is composed of Visual Basic.

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A Study on Optimal Reflux Ratio for Batch Distillation (회분식 증류공정의 환류비 최적에 관한 연구)

  • 이영상;이의수
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.10
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    • pp.833-841
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    • 2002
  • We develope a model that can manipulate the reflux ratio of a batch distillation process in real time for optimal operations. Firstly, reflux ratio decision model for batch distillation unit was developed using the simple short-cut method. Secondly, more detailed rigorous method was applied to improve the accuracy of the model. Based on these models, operational strategies for the optimal reflux ratio was proposed. The results are illustrated with suitable examples and compared with the results using commercial simulator.

THE EFFECT OF INFLATION RISK AND SUBSISTENCE CONSTRAINTS ON PORTFOLIO CHOICE

  • Lim, Byung Hwa
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.17 no.2
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    • pp.115-128
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    • 2013
  • The optimal portfolio selection problem under inflation risk and subsistence constraints is considered. There are index bonds to invest in financial market and it helps to hedge the inflation risk. By applying the martingale method, the optimal consumption rate and the optimal portfolios are obtained explicitly. Furthermore, the quantitative effect of inflation risk and subsistence constraints on the optimal polices are also described.

Optimal supervisory control (최적 제어를 위한 Supervisory control)

  • 박홍성;김면집;노갑선;권욱현
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.498-503
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    • 1991
  • This paper presents a framework of a optimal supervisory controller, which consists of decision rules and the supervisory controller proposed by Ramadge and Wonham. From the presented framwork we obtain optimal control patterns minimizing the given cost functions. The properties of the presented optimal supervisory controller are discussed. Two examples are given to illustrate a designing method of the optimal supervisory controller.

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The optimal paremeter design of rapid thermal processing to improve wafer temperature uniformity on the semiconductor manufacturing (반도체 공정에서 웨이퍼의 온도균일도향상을 위한 고속열처리공정기의 최적 파라미터 설계)

  • 최성규;최진영;권욱현
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1508-1511
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    • 1997
  • In this paper, design parameters of Rapid Thermal Processing(RrW) to minimize the wafer tempera ture uniformity errors are proposed. 1,anip ling positions and the wafer height are important parameters for waf er temperature uniformity in R'I'P. We propose the method to seek lamp ling positions and the wafer height for optimal temperature uniformity. l'he ~~roposed method is applied to seek optimal lamp ling positions and the waf er height of 8 inch wafer. 'I'o seek the optimal lamp ling positions and the wafer height, we var\ulcorner. lamp ling 110s itions and the wafer height and then formulate the wafer temperature uniformity problem to the linear programmi ng problem. Finally, it is shown that the wafer temperature uniformity in RI'I' designed by optimal prarneters is improved to comparing with Ii'l'P designed by the other method.

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Optimal Governor Response Power Flow with Nonlinear Interior Point Method (비선형 내점법을 이용한 최적 조속기 응동 조류계산)

  • Kim, Tae-Gyun;Lee, Byong-Joon;Song, Hwa-Chang;Cha, Jun-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.9
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    • pp.1527-1534
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    • 2007
  • This paper proposes a new concept of optimal governor-response power flow (OGPF) to obtain an optimal set of control parameters when the systems are in mid-term conditions after disturbances, ignoring the system dynamics. The idea of GOPF simply comes from the attempt to find an optimal solution of the governor-response power flow (GPF), which is a pre-exiting tool that is used to get power flow solutions that would exist several seconds after an event is applied. GPF incorporates the simplified model of governors in the systems into the power flow equations. This paper explains the concept of OGPF and depicts the OGPF formulation and application of a nonlinear interior point method as the solution technique. Also, this paper includes an example with New England 39-bus test system to illustrate the effectiveness of GOPF.

A Study on the Optimal Shape Design of 2-D Structures (2차원 구조물의 최적형상설계에 관한 연구)

  • 김홍건;양성모;노홍길;나석찬;유기현;조남익
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.2
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    • pp.9-16
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    • 2003
  • A strategy of the optimal shape design with FEA(Finite Element Analysis) for 2-D structure is proposed by comparing subproblem approximation method with first order approximation method. A cantilever beam with two different loading conditions, a concentrated load and an evenly distribute load, and truss structure with a concentrated loading condition are implemented to optimize the shape. It gives a good design strategy on the optimal truss structure as well as the optimal cantilever beam shape. It is found that the convergence is quickly finished with the iteration number below ten. Optimized shapes of cantilever beam and truss structure are shown with stress contour plot by the results of the subproblem approximation method and the first order approximation methd.

Optimal position selection of sensors and transducers for noise control of 3D (3차원 공간의 소음 제어를 위한 센서 및 트랜스듀서 최적위치 선정)

  • Lee, Hong-Won;Seo, Sung-Dae;Nam, Hyun-Do
    • Proceedings of the KIEE Conference
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    • 2003.11b
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    • pp.107-110
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    • 2003
  • In this paper, the optimal position selection of error sensors and transducers to attenuate interior noise from outside noise sources using active control techniques is presented. To get an optimal control characteristics in adaptive noise control systems, it is necessary to optimize the positions of sensors and transducers. A new type of simulated annealing method has been proposed as searching technique to find optimal transducers and sensors positions in which the sum of the squared pressures at sensor position in an enclosure can be best minimized. Computer simulations and experiments have been performed to show the effectiveness of the proposed method.

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Optimal Design of Mechanisms Using a Least Experimental Plan Method (최소 실험계획법을 이용한 기구의 최적설계)

  • 김충웅;박태원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.11
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    • pp.2883-2893
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    • 1994
  • Use of computers in design is a trend in recent years. Mechanism design also uses computers extensively and the concept of optimal mechanism design is developed in many ways. Various authors presented methods based on sensitivity analysis but in these cases, the governing equation of the mechanism has to be derived and calculations become very complicated. In this papers, a method based on the least experimental plan is presented. To make a model of a mechanism, a general purpose mechanism analysis program is used. To obtain an optimal design of a mechanism, the relationship between design variables and the objective function is represented as the nonlinear equation. Optimal design variables are found by solving this derived equation and its result is verified. An example is presented to show the effectiveness of this method.