• Title/Summary/Keyword: Numerical algorithms

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Pole Assignment for Structural Active Control

  • Vongchavalitkul, Sanguan
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.5-7
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    • 2004
  • Significant progress has been achieved in the active control of civil-engineering structures, not only in the control algorithm, but also in control testing of the scaled model and full-scale building. At the present time, most algorithms used in the active control of civil engineering structures are based on the various active control techniques. In this paper represents active control method, by using pole assignment for reducing structural vibration under excited load. Numerical simulations are performed to assess the effectiveness of pole assignment control system. The relative displacement of structure system is significantly reduced.

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Analysis of Progressive Fracture in Concrete using Finite Elements with Embedded Discontinuous Line (내부 불연속 요소를 사용한 콘크리트의 파괴진행해석)

  • 송하원;우승민;김형운
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.450-455
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    • 1998
  • In this paper, finite element with embedded discontinuous line is introduced in order to avoid the difficulties of adding new nodal points along with crack growth in discrete crack model. With the discontinuous element using discontinuous shape function, stiffness matrix of finite element is derived and dual mapping technique for numerical integration is employed. Using the finite element program made with employed algorithms, algorithm is verified and fracture analysis of simple concrete beam is performed.

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A PROJECTION ALGORITHM FOR SYMMETRIC EIGENVALUE PROBLEMS

  • PARK, PIL SEONG
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.3 no.2
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    • pp.5-16
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    • 1999
  • We introduce a new projector for accelerating convergence of a symmetric eigenvalue problem Ax = x, and devise a power/Lanczos hybrid algorithm. Acceleration can be achieved by removing the hard-to-annihilate nonsolution eigencomponents corresponding to the widespread eigenvalues with modulus close to 1, by estimating them accurately using the Lanczos method. However, the additional Lanczos results can be obtained without expensive matrix-vector multiplications but a very small amount of extra work, by utilizing simple power-Lanczos interconversion algorithms suggested. Numerical experiments are given at the end.

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MULTIGRID METHODS FOR THE PURE TRACTION PROBLEM OF LINEAR ELASTICITY: FOSLS FORMULATION

  • Lee, Chang-Ock
    • Communications of the Korean Mathematical Society
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    • v.12 no.3
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    • pp.813-827
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    • 1997
  • Multigrid methods for two first-order system least squares (FOSLS) using bilinear finite elements are developed for the pure traction problem of planar linear elasticity. They are two-stage algorithms that first solve for the gradients of displacement, then for the displacement itself. In this paper, concentration is given on solving for the gradients of displacement only. Numerical results show that the convergences are uniform even as the material becomes nearly incompressible. Computations for convergence rates are included.

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AN AUTOMATIC AUGMENTED GALERKIN METHOD FOR SINGULAR INTEGRAL EQUATIONS WITH HILBERT KERNEL

  • Abbasbandy, S.;Babolian, E.
    • Journal of applied mathematics & informatics
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    • v.8 no.2
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    • pp.429-437
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    • 2001
  • In [1, 2], described a Chebyshev series method for the numerical solution of integral equations with three automatic algorithms for computing tow regularization parameters, C/sub f/ and r. Here we describe a Fourier series expansion method for a class singular integral equations with Hilbert kernel and constant coefficients with using a new automatic algorithm.

Joint Replenishment and Delivery Scheduling in a Supply Chain (공급사슬에서 다품목 일괄구매 및 조달 일정계획에 관한 연구)

  • Cha, Byung-Chul;Moon, Il-Kyeong
    • IE interfaces
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    • v.17 no.spc
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    • pp.90-96
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    • 2004
  • In this paper, we consider the joint replenishment problem of a one-warehouse, n-retailer system. We introduce a joint replenishment and delivery strategy of a warehouse and develop a mathematical model based on the proposed strategy. Two efficient algorithms are presented and compared using numerical examples. The proposed strategy is compared with the common cycle strategy for 1,600 randomly generated problems, and has been proven to be superior to the common cycle strategy.

Comparison of Algorithms for Two-way Stratification Design

  • Kim, Sun-Woong
    • Communications for Statistical Applications and Methods
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    • v.11 no.1
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    • pp.139-151
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    • 2004
  • Kim et al. (2002) developed public use SAS-based software for two-way stratification design, which is called SOCSLP We describe the details of a new approach implemented using SOCSLP and key differences between the approach and the sampling schemes of Sitter and Skinner (1994) and Winkler (2001). In addition, a numerical example is given to compare those methods with respect to the probabilities of selecting sample arrays.

Improved Two Points Algorithm For D-optimal Design

  • Ahn, Yunkee;Lee, Man-Jong
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.53-68
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    • 1999
  • To improve the slow convergence property of the steepest ascent type algorithm for continuous D-optimal design problems. we develop a new algorithm. We apply the nonlinear system of equations as the necessary condition of optimality and develop the two-point algorithm that solves the problem of clustering. Because of the nature of the steepest coordinate ascent algorithm avoiding the problem of clustering itself helps the improvement of convergence speed. The numerical examples show the performances of the new method is better than those of various steepest ascent algorithms.

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Application of Regularization Method to Angle-resolved XPS Data (각분해X-선광전자분광법 데이터 분석을 위한 regularization 방법의 응용)

  • 노철언
    • Journal of the Korean Vacuum Society
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    • v.5 no.2
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    • pp.99-106
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    • 1996
  • Two types of regularization method (singular system and HMP approaches) for generating depth-concentration profiles from angle-resolved XPS data were evaluated. Both approaches showed qualitatively similar results although they employed different numerical algorithms. The application of the regularization method to simulated data demonhstrates its excellent utility for the complex depth profile system . It includes the stable restoration of depth-concentration profiles from the data with considerable random error and the self choice of smoothing parameter that is imperative for the successful application of the regularization method. The self choice of smoothing parameter is based on generalized cross-validation method which lets the data themselves choose the optimal value of the parameter.

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Control of Chaos using M-step ahead prediction (M단계 예측방법을 이용한 혼돈현상 제어)

  • 이철목;권영석;이균경
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.85-88
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    • 1996
  • We develop an efficient technique of controlling chaos using M-step ahead prediction with the OGY method. It has smaller transient time than the OGY method, and prevents burst phenomena that occur in noisy environment. This technique is very simple and needs small memory compared with targeting algorithms. Numerical examples show that the proposed algorithm has good performance, especially in noisy environment.

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