• Title/Summary/Keyword: initial basis

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On the Construction of Initial Basis in the Simplex Method (단체법에서 효과적인 초기기저의 설정)

  • 임성묵;김기태;박순달
    • Korean Management Science Review
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    • v.17 no.2
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    • pp.13-20
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    • 2000
  • In this research, we compare and analyze the two initial basis construction procedures: LPAKO’s procedure proposed by Seo et. al. and symbolic crash procedure proposed by Maros et. al.. Based on the analysis, we present a new procedure which complements the previous procedures. The new procedure shows superiority to the previous procedures with respects to the optimality of initial basis. Also, the linear basis Also. the initial basis constructed by the new procedure reduces the number of simplex iterations.

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A study on constructing a good initial basis in the simplex method (단체법에서의 초기기저 구성에 관한 연구)

  • 서용원;김우제;박순달
    • Korean Management Science Review
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    • v.13 no.3
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    • pp.105-113
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    • 1996
  • Constructing an initial basis is an important process in the simplex method. An initial basis greatly affects the number of iterations of iterations and the execution time in the simplex method. The purpose of this paper is to construct a good initial basis. First, to avoid linear dependency among the chosen columns, an enhanced Gaussian elimination method and a method using non-duplicated nonzero elements are developed. Second, for an order to choose variables, the sparsity of the column is used. Experimenal results show that the proposed method can reduce the number of iterations and the execution time compared with Bixby's method by 12%.

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Numerical solving of initial-value problems by Rbf basis functions

  • Gotovac, Blaz;Kozulic, Vedrana
    • Structural Engineering and Mechanics
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    • v.14 no.3
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    • pp.263-285
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    • 2002
  • This paper presents a numerical procedure for solving initial-value problems using the special functions which belong to a class of Rvachev's basis functions $R_{bf}$ based on algebraic and trigonometric polynomials. Because of infinite derivability of these functions, derivatives of all orders, required by differential equation of the problem and initial conditions, are used directly in the numerical procedure. The accuracy and stability of the proposed numerical procedure are proved on an example of a single degree of freedom system. Critical time step was also determined. An algorithm for solving multiple degree of freedom systems by the collocation method was developed. Numerical results obtained by $R_{bf}$ functions are compared with exact solutions and results obtained by the most commonly used numerical procedures for solving initial-value problems.

Optimization of the Radial Basis Function Network Using Time-Frequency Localization (시간-주파수 분석을 이용한 방사 기준 함수 구조의 최적화)

  • 김성주;김용택;조현찬;전홍태
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.459-462
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    • 2000
  • In this paper, we propose the initial optimized structure of the Radial Basis Function Network which is more simple in the part of the structure and converges more faster than Neural Network with the analysis method using Time-Frequency Localization. When we construct the hidden node with the Radial Basis Function whose localization is similar with an approximation target function in the plane of the Time and Frequency, we make a good decision of the initial structure having an ability of approximation.

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Initial Optimization of the RBFN with Time-Frequency Localization Using Genetic Algorithm (유전 알고리즘과 시간-주파수 지역화를 이용한 방사 기준 함수망의 초기 최적화)

  • 김성주;서재용;김용택;조현찬;전홍태
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2001.12a
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    • pp.221-224
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    • 2001
  • In this paper, we propose the initial optimized structure of the Radial Basis Function Network which is more simple in the part on the structure and converges more faster than Neural Network with the analysis method using Time-Frequency Localization and genetic algorithm. When we construct the hidden node with the Radial Basis Function whose localization is similar with an approximation target function in the plane of the Time and Frequency, we have initial structure of RBFN, After that, we evaluate the parameters of RBF in the network and the parameters needed for the network is more a few. Finally, we make a good decision of the initial structure having an ability of approximation.

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Optimal Design of Radial Basis Function Network Using Time-Frequency Localization (시간-주파수 지역화를 이용한 방사 기준 함수 구조의 최적 설계)

  • Kim, Yong-Taek;Kim, Seong-Joo;Seo, Jae-Yong;Jeon, Hong-Tae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.38 no.5
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    • pp.1-6
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    • 2001
  • In this paper, we propose the initial optimized structure of the Radial Basis Function Network(RBFN) which is more simple in the part of the structure and converges more faster than Neural Network. For this, we use the analysis method using time frequency localization and we can decide the initial structure of the RBFN suitable for the given problem. When we compose the hidden nodes with the radial basis functions whose localization are similar with the target function in the plane of the time and frequency, we can make a good decision of the initial structure having an ability of approximation.

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Optimization for the Initial Designed Structure by Localization Using Genetic Algorithm

  • Kim, Seong-Joo;Kim, Yong-Taek;Ko, Jae-Yang;Jeon, Hong-Tae
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1650-1653
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    • 2002
  • In this paper, we propose the initial optimized structure of the Radial Basis function Networks that is simple in the part of the structure and fast converges more than neural networks with the analysis method using Time- Frequency Localization. We construct the hidden node with the Radial Basis functions their localization are similar with approximation target function in the plane of the Time and Frequency. We finally make a good decision of the initial structure for function approximation using genetic algorithm

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NETWORK DESIGN AND PREPROCESSING FOR MULTI-SCALE SPHERICAL BASIS FUNCTION REPRESENTATION

  • Oh, Hee-Seok;Kim, Dong-Hoh
    • Journal of the Korean Statistical Society
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    • v.36 no.2
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    • pp.209-228
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    • 2007
  • Given scattered surface air temperatures observed by a network of weather stations, it is an important problem to estimate the entire temperature field for every location on the globe. Recently, a multi-scale spherical basis function (SBF) representation was proposed by Li (1999) for representing scattered data on the sphere. However, for a successful application of Li (1999)'s method, some practical issues such as network design, bandwidth selection of SBFs and initial coefficients are to be resolved. This paper proposes automatic procedures to design network and to select bandwidths. This paper also considers a preprocessing problem to obtain a stable initial coefficients from scattered data. Experiments with real temperature data demonstrate the promising empirical properties of the proposed approaches.

Origin of the Initial Permeability of Manganese-Zinc Ferrite Polycrytals (Mn-Zn 페라이트 다결정의 조성에 따른 투자율의 변화 기구)

  • 변순천;제해준;고경현;홍국선
    • Journal of the Korean Ceramic Society
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    • v.34 no.4
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    • pp.351-356
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    • 1997
  • The origin of the variation of initial permeability in manganese-zinc ferrite polycrystals with a content of hematite was investigated. Initial permeability showed maximum with hematite content while there was no significant change in microstructure. Saturation magnetization increased with hematite content. So the variation of initial permeability was not explained on the basis of microstructural change or saturation magnetization. Temperature dependence of initial permeability revealed magnetocrystalline anisotropy was the origin of the variation of initial permeability. The change in magnetocrystalline anisotropy was ascribed to the variation in ferrous ion concentration. Therefore the variation of initial permeability in manganese-zinc ferrite polycrystals with a content of hematite was due to ferrous ion concentration via magnetocrystalline anisotropy.

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Seismic refraction tomographic inversion using the initial velocity model from marine reflection data (해양 반사법 탐사자료의 초기속도 모델을 이용한 굴절 토모그래피 역산)

  • Lee, Yong-Jae;Kim, Won-Sik;Lee, Ho-Young;Yoo, Dong-Geun;Cho, Chang-Soo;Kim, Ji-Soo
    • 한국지구물리탐사학회:학술대회논문집
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    • 2007.06a
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    • pp.317-322
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    • 2007
  • Seismic exploration is divided by reflection and refraction method greatly, and reflection method can analyze complicated underground structure in the basis high resolution image, and refraction method can grasp the velocity structure of underground accurately. This thesis confirmed application of mixed exploration techniques using advantages of reflection and refraction. Reflection data processing applied conventional technique, and inversion of refraction data applied travel time tomographic technique that using SIRT method. Also, could establish initial information in model variable and improved the result of inversion by restricting model parameter value and dimension of area. Confirmed efficient fact in sequence and velocity structure grasping by utilizing accurate initial velocity model made out on the basis of marine reflection data, and mixed exploration technique using reflection and refraction have propriety that can trust in field application.

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