• 제목/요약/키워드: nonlinear minimization

검색결과 156건 처리시간 0.032초

지역화회귀모형을 이용한 유량관측망의 계측 (Planning of Streamflow Data Collection Network by Regionalized Regression Model)

  • 조국광;권순국
    • 물과 미래
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    • 제23권1호
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    • pp.109-118
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    • 1990
  • 본 연구에서는 한강 및 낙동강유역의 유량관측망에 대하여 개발된 지역화회귀모형을 이용하여 모형이 지니는 평균표본오차의 최소화를 목적함수로 하는 비선형 정수계획법에 의하여 5,6,10,15 및 20년의 계획년수를 갖는 각 운영계획에 따른 기존 관측망의 유효성을 평가하며, 경제적인 측면에서 관측망효율을 증가시킬 수 있도록 하천유량관측망을 조정·계획하였다.

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유한요소법과 SUMT를 이용한 동기형 릴럭턴스 전동기의 용량에 따른 회전자 구조 최적설계 (Optimum Design Criteria Based on the Rated Watt of a Synchronous Reluctance Motor Using a Coupled FEM & SUMT)

  • 권선범;이중호
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제54권8호
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    • pp.364-369
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    • 2005
  • This paper deals with an automatic optimum design based on a rated output for a synchronous reluctance motor (SynRM). The focus of this paper is the motor design relative to the output power on the basis of rotor shape of a SynRM in each rated watt. And optimization algorithm is used by means of sequential unconstrained minimization technique(SUMT). The coupled Finite Elements Analysis (FEA) & Preisach model have been used to evaluate nonlinear solutions. The proposed procedure allows to define the rotor geometric dimensions according to rated watt starting from an existing motor or a preliminary design.

퍼지 이론과 슬라이딩모드 제어를 이용한 스위치드 릴럭턴스 전동기의 토크리플 저감 (Torque Ripple Minimization for Switched Reluctance Motors Using a Fuzzy Logic and Sliding Mode Control)

  • 윤재승;김동희;신혜웅;이교범
    • 전기학회논문지
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    • 제63권10호
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    • pp.1384-1392
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    • 2014
  • This paper presents a torque ripple reduction algorithm for the switched reluctance motor drives using the fuzzy logic and the sliding mode control. A turn-on angle controller based on the fuzzy logic determines the optimal turn-on angle. In addition, a sliding mode torque control (SMTC) methods reduces torque ripples instantaneously in the commutation region. The proposed algorithm does not require complex system models considering nonlinear magnetizing or demagnetizing periods of the phase current. According to the rotor speed and torque, the proposed controller changes the turn-on angle and reference torque instantaneously until the torque ripples are minimized. The simulation and experimental results verify the validity of minimizing the torque ripple performance.

Improved Analytical Modeling of a Ellipse Shape Permanent Magnet Rotor in Ultra-High-Speed Brushless DC motor for the Reduction of Torque Ripple

  • Sung, So-Young;Jeong, Jae-Hoon;Choi, Ji-Hwan;Park, Hyung-Il;Jang, Seok-Myeong
    • Journal of Electrical Engineering and Technology
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    • 제8권4호
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    • pp.945-950
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    • 2013
  • This paper deals with the ellipse permanent magnet machines for the minimization of torque ripple based on electromagnetic field theory. On the basis of a magnetic vector potential and a two dimensional (2-D) polar system, analytical solutions for flux density due to permanent magnet (PM) and current are obtained. In particular, the analytical solutions for mathematical expressions of magnets with different circumferential thicknesses can be solved introducing improved magnetization modeling techniques. The analytical results are validated extensively be nonlinear finite element solutions, a reduction of torque ripple can be achieved.

Geometric Fitting of Parametric Curves and Surfaces

  • Ahn, Sung-Joon
    • Journal of Information Processing Systems
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    • 제4권4호
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    • pp.153-158
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    • 2008
  • This paper deals with the geometric fitting algorithms for parametric curves and surfaces in 2-D/3-D space, which estimate the curve/surface parameters by minimizing the square sum of the shortest distances between the curve/surface and the given points. We identify three algorithmic approaches for solving the nonlinear problem of geometric fitting. As their general implementation we describe a new algorithm for geometric fitting of parametric curves and surfaces. The curve/surface parameters are estimated in terms of form, position, and rotation parameters. We test and evaluate the performances of the algorithms with fitting examples.

펴지 제어기의 소속함수 최소화에 관한 연구 (Minimization of Membership Function with Fuzzy Control)

  • 주한조;박승훈;홍대승;임화영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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    • pp.968-970
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    • 2003
  • Fuzzy Controller is a system that displays a person's thoughts using membership function and IF-THEN rules. With the help of specialists' knowledge, rule bases can be explained in easy language. Furthermore Fuzzy Controller has strong resistance against turbulence. Its performance is especially prominent when targets cannot be measured in mathematic methods because the fuzzy controller can measure the output using only the relations between the input and output. But Fuzzy System has a problem that is calculation speed. I suggest you a theory to solve it. I applied a theory to inverted pendulum. Because it is represent of nonlinear system.

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SUMT를 이용한 동기형 릴럭턴스 전동기의 용량에 따른 회전자 최적설계 (Optimum design criteria based on the rated watt of a Synchronous Reluctance Motor using a coupled FEM & SUMT)

  • 권선범;박중민;이중호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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    • pp.1095-1097
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    • 2005
  • This paper deals with an automatic design standard computation based on a rated watt for a synchronous reluctance motor(SynRM). The focus of this paper is making the design relative to the output power on the basis of rotor shape of a SynRM in each rated watt using a coupled FEM & sequential unconstrained minimization technique(SUMT). The coupled finite elements analysis(FEA) & Preisach model have been used to evaluate nonlinear solutions. The proposed procedure allows to define the rotor geometric dimensions according to the rotor diameter and rated watt starting from an existing motor or a preliminary design.

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Solving a Matrix Polynomial by Conjugate Gradient Methods

  • Ko, Hyun-Ji;Kim, Hyun-Min
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제11권4호
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    • pp.39-46
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    • 2007
  • One of well known and much studied nonlinear matrix equations is the matrix polynomial which has the form G(X)=$A_0X^m+A_1X^{m-1}+{\cdots}+A_m$ where $A_0$, $A_1$, ${\cdots}$, $A_m$ and X are $n{\times}n$ real matrices. We show how the minimization methods can be used to solve the matrix polynomial G(X) and give some numerical experiments. We also compare Polak and Ribi$\acute{e}$re version and Fletcher and Reeves version of conjugate gradient method.

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자동창고비용 최소화 모델 및 해법에 관한 연구 (A Solution Procedure for Minimizing Costs in Automated Storage/Retrieval Systems Design)

  • 나윤균;이동하
    • 산업경영시스템학회지
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    • 제22권49호
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    • pp.1-10
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    • 1999
  • A cost minimization model for designing AS/RS (Automated Storage/Retrieval Systems) has been developed, whose objective function includes penalty cost caused by the incapability of meeting throughput rate requirements as well as S/R machine cost, storage rack cost, and interface conveyor cost. Since the model is a nonlinear integer programming problem which is very hard to solve with large problem size the problem is divided into four cases according to the ratio of horizontal S/R machine speed to its vertical speed and the existence of the penalty cost. A solution procedure is developed which solves each problem exactly under the different number of S/R machines.

OUTER APPROXIMATION METHOD FOR ZEROS OF SUM OF MONOTONE OPERATORS AND FIXED POINT PROBLEMS IN BANACH SPACES

  • Abass, Hammad Anuoluwapo;Mebawondu, Akindele Adebayo;Narain, Ojen Kumar;Kim, Jong Kyu
    • Nonlinear Functional Analysis and Applications
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    • 제26권3호
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    • pp.451-474
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    • 2021
  • In this paper, we investigate a hybrid algorithm for finding zeros of the sum of maximal monotone operators and Lipschitz continuous monotone operators which is also a common fixed point problem for finite family of relatively quasi-nonexpansive mappings and split feasibility problem in uniformly convex real Banach spaces which are also uniformly smooth. The iterative algorithm employed in this paper is design in such a way that it does not require prior knowledge of operator norm. We prove a strong convergence result for approximating the solutions of the aforementioned problems and give applications of our main result to minimization problem and convexly constrained linear inverse problem.