• Title/Summary/Keyword: approximation technique

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NUMERICAL SIMULATION OF THE FRACTIONAL-ORDER CONTROL SYSTEM

  • Cai, X.;Liu, F.
    • Journal of applied mathematics & informatics
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    • v.23 no.1_2
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    • pp.229-241
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    • 2007
  • Multi-term fractional differential equations have been used to simulate fractional-order control system. It has been demonstrated the necessity of the such controllers for the more efficient control of fractional-order dynamical system. In this paper, the multi-term fractional ordinary differential equations are transferred into equivalent a system of equations. The existence and uniqueness of the new system are proved. A fractional order difference approximation is constructed by a decoupled technique and fractional-order numerical techniques. The consistence, convergence and stability of the numerical approximation are proved. Finally, some numerical results are presented to demonstrate that the numerical approximation is a computationally efficient method. The new method can be applied to solve the fractional-order control system.

Approximation to the Probability of Downlink Blocking between cdma2000 1X and WCDMA in Urban Handover Areas (도심 핸드오프 지역에서의 cdma2000 1X와 WCDMA간의 다운링크 블록킹 확률 근사)

  • 박승근;조경록;박덕규
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.2
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    • pp.89-95
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    • 2003
  • This paper proposes downlink blocking model and approximation equation using lower bound approximation in order to determine the proper guard band between cdma2000 1X and WCDMA in handover areas. The frequency sharing conditions obtained by the model and approximation equation on blocking probability proposed in the paper, are co-site of base station and guard band higher than 1 MHz. Also, the proposed equation is in the form of Q-function. It is an analytical solution overcoming the drawback of recalculation, belonged to Monte-Carlo technique.

Wavelet network approximation and coefficient learning of linear-time-varying system (시변 선형 시스템의 웨이브렛망 근사화와 가중치의 학습)

  • 이영석;김동옥;서보혁
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.728-731
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    • 1997
  • This paper discusses approximation modelling of discrete-time linear time-varying system(LTVS). The wavelet transform is considered as a tool for representing and approximating a LTVS. The joint time-frequency properties of wave analysis are appropriate for describing the LTVS. Simulation results is included to illustrate the potential application of the technique.

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The nonlinear function approximation based on the neural network application

  • Sugisaka, Masanori;Itou, Minoru
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.462-462
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    • 2000
  • In this paper, genetic algorithm (GA) is the technique to search for the optimal structures (i,e., the kind of neural network, the number of hidden neuron, ..) of the neural networks which are used approximating a given nonlinear function, In this paper, we used multi layer feed-forward neural network. The decision method of synapse weights of each neuron in each generation used back-propagation method. In this study, we simulated nonlinear function approximation in the temperature control system.

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Image Reconstruction of Dielectric Cylinder Under Born Approximation Using a Coherent Tomographic Scheme in the Spatial Domain (공간영역에서 코히어런트 단층촬영 기법을 이용한 Born 근사하에 유전체 기둥의 영상제현)

  • 서경환;김상기;김세윤;라정웅
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.9
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    • pp.1327-1335
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    • 1990
  • In this paper, using the principle of duality between the spatial and spectral domain, we proposed a new microwave imaging technique of a coherent tomographic formulation in the spatial domain and reconstructed the image of dielectric cylinder through simulation and experiment. The numerical and experimental results for the variety o object size, relative dielectric constant have shown the limitation of Born approximation to be used and the effect of retrieved images for various signal bandwidth.

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Optimum Preliminary Ship Design Technique by Using Sophisticated Sequential Linear Approximation Method -Development and Application of User Oriented Design Optimization Language- (고성능 순차적 선형화 방법을 이용한 선박 최적 초기설계 기법 -최적화 설계 전용 언어의 개발 및 응용-)

  • K.Y.,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.25 no.3
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    • pp.35-45
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    • 1988
  • This paper presents a sophisticated Sequential Linear Approximation Method(SLAM) to solve nonlinear optimization problem and the performance of this method is compared with those of the Penalty Function Method(SUMT), Tangent Search Method(TSM) and Flexible Tolerance Method(FTM). To improve the convenience and flexibility in using the proposed SLAM, an user oriented design optimization language is developed and the application examples are shown for the optimization of propeller principal dimensions and the optimization of bulk carrier principal particulars.

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On A Symbolic Method for Error Estimation of a Mixed Interpolation

  • Thota, Srinivasarao
    • Kyungpook Mathematical Journal
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    • v.58 no.3
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    • pp.453-462
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    • 2018
  • In this paper, we present a symbolic formulation of the error obtained due to an approximation of a given function by the mixed-interpolating function. Using the proposed symbolic method, we compute the error evaluation operator as well as the error estimation at any arbitrary point. We also present an algorithm to compute an approximation of a function by the mixed interpolation technique in terms of projector operator. Certain examples are presented to illustrate the proposed algorithm. Maple implementation of the proposed algorithm is discussed with sample computations.

Optimization of RC Piers Based on Efficient Reanalysis Technique (효율적인 재해석 기법에 의한 RC 교각의 최적설계)

  • 조효남;민대홍;신만규
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.199-204
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    • 2000
  • In this study, an optimum design algorithm using efficient reanalysis is proposed for seismic design of RC Piers. The proposed algorithm for optimization of RC Piers is based on efficient reanalysis technique. Considering structural behavior of RC Piers, several other approximation techniques, such as artificial constraint deletion is introduced to increase the efficiency of optimization. The efficiency and robustness of the proposed algorithm increase the proposed reanalysis technique is demonstrated by comparing it with a conventional optimization algorithm. A few of design examples are optimized to show the applicability of the proposed algorithm.

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Node Activation Technique for Finite Element Model : Ⅰ. Theory (유한요소 모델의 절점 활성화 기법 : Ⅰ. 이론)

  • Jo, Jin Yeon;Kim, Do Nyeon;Kim, Seung Jo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.4
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    • pp.26-34
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    • 2003
  • In this paper, a novel technique is proposed to arbitrarily activate the nodal points in finite element model through the meshless approximation methods such as MLS(moving least squares method), and theoretical investigations are carried out including the consistency and boundeness of numerical solution to prove the validity of the proposed method. By using the proposed node activation technique, one can activate and handle only the concerned nodes as unknown variables among the large number of nodal points in the finite element model. Therefore, the proposed technique has a great potential in design and reanalysis procedure.

Structural Behavior Characteristics and Efficiency Evaluation of Outrigger System using Stiffness-Based Optimal Design Technique (강성최적설계법을 이용한 아웃리거 시스템의 거동특성 및 효율성 평가)

  • Kim, Ho-Soo;Lee, Han-Joo
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.3 s.17
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    • pp.123-130
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    • 2005
  • This study presents an effective stiffness-based optimal technique to control quantitatively lateral drift and evaluate the structural behavior characteristics and efficiency for tall outrigger system subject to lateral loads. To this end, displacement sensitivity depending on behavior characteristics of outrigger system is established and approximation concept that preserves the generality of the mathematical programming and can efficiently solve large scale problems is introduced. Specifically, under the 'constant-shape' assumption, resizing technique of member is developed. Four types of 50 story frameworks are presented to illustrate the features of the quantitative lateral drift control technique proposed in this study.

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