• Title/Summary/Keyword: Solution Technique

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Comparative Study on Dimensionality and Characteristic of PSO (PSO의 특징과 차원성에 관한 비교연구)

  • Park Byoung-Jun;Oh Sung-Kwun;Kim Yong-Soo;Ahn Tae-Chon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.4
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    • pp.328-338
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    • 2006
  • A new evolutionary computation technique, called particle swarm optimization(PSO), has been proposed and introduced recently. PSO has been inspired by the social behavior of flocking organisms, such as swarms of birds and fish schools and PSO is an algorithm that follows a collaborative population-based search model. Each particle of swarm flies around in a multidimensional search space looking for the optimal solution. Then, Particles adjust their position according to their own and their neighboring-particles experience. In this paper, characteristics of PSO such as mentioned are reviewed and compared with GA which is based on the evolutionary mechanism in natural selection. Also dimensionalities of PSO and GA are compared throughout numeric experimental studies. The comparative studies demonstrate that PSO is characterized as simple in concept, easy to implement, and computationally efficient and can generate a high-quality solution and stable convergence characteristic than GA.

Robust $H_{\infty}$ Control for Bilinear Systems with Parameter Uncertainties via output Feedback

  • Kim, Young-Joong;Lee, Su-Gu;Chang, Sae-Kwon;Kim, Beom-Soo;Lim, Myo-Taeg
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.386-391
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    • 2003
  • This paper focuses on robust $H_{\infty}$ control for bilinear systems with time-varying parameter uncertainties and exogenous disturbance via output feedback. $H_{\infty}$ control is achieved via separation into a $H_{\infty}$ state feedback control problem and a $H_{\infty}$ state estimation problem. The suitable robust stabilizing output feedback control law can be constructed in term of approximated solution to x-dependent Riccati equation using successive approximation technique. Also, the $H_{\infty}$ filter gain can be constructed in term of solution to algebraic Riccati equation. The output feedback control robustly stabilizes the plant and guarantees a robust $H_{\infty}$ performance for the closed-loop systems in the face of parameter uncertainties and exogenous disturbance.

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Measurement of Crystal Formation in Supersaturated Solution

  • Kim, Byung-Chul;Kim, Young-Han
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1196-1200
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    • 2003
  • The degree of supersaturation is an important measure for the operation of crystallization processes, because it is directly related to the control of crystal size distribution and shape. A conventional technique utilizing solution composition and temperature has a variety of problems caused from the measurement error and the handling of analyzing samples. A monitoring system of the supersaturation using a quartz crystal sensor is proposed here, and its performance is examined applying different manipulations of coolant temperature. The experimental outcome and photographic examination indicate that the measurements of resonant frequency and resistance of the sensor can be used for the prediction of the formation and growth of solid crystal from the crystallization process. The monitoring system eliminates the intrinsic error source of the conventional system to give the improved measurement and on-line application availability.

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A Study on Minimum Volume of Highly Homogeneous Superconducting Coil (균일자장 초전도코일의 체유최소화에 관한 연구)

  • 이승원;권영안
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.34 no.1
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    • pp.38-43
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    • 1985
  • Since the superconductor type II with high critical current and high critical magnetic field was discovered in 1961, there were many studies on the superconducting coil for high field and highly homogeneous field. The graphical method and the numerical method by Newton Raphson technique have been studied as the method for design of homogeneous superconducting coil. It is comparatively easy to get a compensating coil for any given main coil by the above methods, but it is too laborious to get a general solution for main coil dimension. This paper studies the optimal design method for minimum volume of superconducting coil under certain central field and highly homogeneous field. The present method makes use of the nonlinear programming for optimization. The optimal solution of NMR superconducting coils by this method are demonstrated very well.

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Emergency Service Restoration and Load Balancing in Distribution Networks Using Feeder Loadings Balance Index (피더부하 균등화지수를 이용한 배전계통의 긴급정전복구 및 부하균등화)

  • Choe, Sang-Yeol;Jeong, Ho-Seong;Sin, Myeong-Cheol
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.5
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    • pp.217-224
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    • 2002
  • This paper presents an algorithm to obtain an approximate optimal solution for the service restoration and load balancing of large scale radial distribution system in a real-time operation environment. Since the problem is formulated as a combinatorial optimization problem, it is difficult to solve a large-scale combinatorial optimization problem accurately within the reasonable computation time. Therefore, in order to find an approximate optimal solution quickly, the authors proposed an algorithm which combines optimization technique called cyclic best-first search with heuristic based feeder loadings balance index for computational efficiency and robust performance. To demonstrate the validity of the proposed algorithm, numerical calculations are carried out the KEPCO's 108 bus distribution system.

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.

An Empirical Study of Production Scheduling Model Establishment by LP Technique (LP기법에 의한 생산계획 모형수립의 실증적 연구)

  • 최원용
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.19 no.40
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    • pp.203-217
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    • 1996
  • This thesis describes a quantitative decision-making of production planning system. A mathmatical model of Linear Programming is used set up a production scheuling under the assumption. As the emphasis is laid on the applicability of the developed model, the linrar programming is applied to establish the production schedule for "F" furniture company which produces kitchin cabinet and OA furniture, The optimal solution is obtained by using the LP package, QBS. By the solution reduced to 14% of work force compared with the real data during all of the planning horizon. And it is also possible to reduce the work-force of the lowest level of employee by 10% for the reasonable management. There are some limitations in computerized data processing, which is only considering the economic costs without considering any external environment of case enterprise. As a result, it is shown that the LP model is very useful method of make aggregate production schedule. schedule.

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An Efficient Time-Domain Electromagnetic Solution Using the Time-Domain Variable Resolution Concept (가변 시간 분해능 시간 영역 전자파 해석법)

  • Kim Hyung-Hoon;Park Jong-Il;Kim Hyeong-Dong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.9 s.112
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    • pp.890-894
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    • 2006
  • To make the best use of known characteristics of the alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method such as unconditional stability and modeling accuracy, an efficient time domain solution with variable time-step size is proposed. Numerical experiment shows that a time-step size for a given mesh size can be increased preserving a desired numerical accuracy over frequencies of interest. The proposed method can be used to analyze electromagnetic problems with reduced computation time.

Value Extrapolation Technique to Solve Retrial Queues: A Comparative Perspective

  • Gimenez-Guzman, Jose Manuel;Domenech-Benlloch, Ma Jose;Pla, Vicent;Casares-Giner, Vicente;Martinez-Bauset, Jorge
    • ETRI Journal
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    • v.30 no.3
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    • pp.492-494
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    • 2008
  • While the retrial phenomenon plays an important role in communication networks and should not be ignored, retrial systems do not present an exact analytic solution, so approximate techniques are required. To the best of our knowledge, all the existing techniques are based on computing the steady states probabilities. We propose another approach based on the relative state values which appear in the Howard equations. The results of the numerical evaluation carried out show that this solution outperforms previous approaches in terms of both accuracy and computation time.

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Sensorless Speed Control of PMSM with Superposition Principle (중첩의 원리를 이용한 센서리스 PMSM속도제어)

  • 이동희;박성준;한성현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.199-205
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    • 2002
  • This application study presents a solution to control a Permanent Magnet Synchronous Motor without sensors. The use of this system yields enhanced operations, fewer system components, lower system cost , energy efficient control system design and increased efficiency. The control method presented is field oriented control (FOC). The sinusoidal voltage waveforms are generated by the power module using the space vector modulation technique. A practical solution is described and results are given in this application Study. The performance of a Sensorless architecture allows an intelligent approach to reduce the complete system costs of digital motion control applications using cheaper electrical motors without sensors. This paper deals with an overview of sensorless solutions in digital motor control applications whereby the focus will be the new Controller without sensors and its applications.

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