• Title/Summary/Keyword: linear approximation

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Bayesian Hypothesis Testing in Multivariate Growth Curve Model.

  • Kim, Hea-Jung;Lee, Seung-Joo
    • Journal of the Korean Statistical Society
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    • v.25 no.1
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    • pp.81-94
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    • 1996
  • This paper suggests a new criterion for testing the general linear hypothesis about coefficients in multivariate growth curve model. It is developed from a Bayesian point of view using the highest posterior density region methodology. Likelihood ratio test criterion(LRTC) by Khatri(1966) results as an approximate special case. It is shown that under the simple case of vague prior distribution for the multivariate normal parameters a LRTC-like criterion results; but the degrees of freedom are lower, so the suggested test criterion yields more conservative test than is warranted by the classical LRTC, a result analogous to that of Berger and Sellke(1987). Moreover, more general(non-vague) prior distributions will generate a richer class of tests than were previously available.

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A FIFTH ORDER NUMERICAL METHOD FOR SINGULAR PERTURBATION PROBLEMS

  • Chakravarthy, P. Pramod;Phaneendra, K.;Reddy, Y.N.
    • Journal of applied mathematics & informatics
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    • v.26 no.3_4
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    • pp.689-706
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    • 2008
  • In this paper, a fifth order numerical method is presented for solving singularly perturbed two point boundary value problems with a boundary layer at one end point. The two point boundary value problem is transformed into general first order ordinary differential equation system. A discrete approximation of a fifth order compact difference scheme is presented for the first order system. An asymptotically equivalent first order equation of the original singularly perturbed two point boundary value problem is obtained from the theory of singular perturbations. It is used in the fifth order compact difference scheme to get a two term recurrence relation and is solved. Several linear and non-linear singular perturbation problems have been solved and the numerical results are presented to support the theory. It is observed that the present method approximates the exact solution very well.

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Fundamental restrictions for the closed-loop control of wind-loaded, slender bridges

  • Kirch, Arno;Peil, Udo
    • Wind and Structures
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    • v.12 no.5
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    • pp.457-474
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    • 2009
  • Techniques for stabilising slender bridges under wind loads are presented in this article. A mathematically consistent description of the acting aerodynamic forces is essential when investigating these ideas. Against this background, motion-induced aerodynamic forces are characterised using a linear time-invariant transfer element in terms of rational functions. With the help of these functions, the aeroelastic system can be described in the form of a linear, time-invariant state-space model. It is shown that the divergence wind speed constitutes an upper bound for the application of the selected mechanical actuators. Even active control with full state feedback cannot overcome this limitation. The results are derived and explained with methods of control theory.

Development of a Dual-Arm Drawing Robot using Line Segment Approximation of Image Edges (윤곽선의 선분 근사화를 활용한 양팔 화가 로봇의 개발)

  • Kim, Jung-Kyu;Lee, Sang-Pil;Jung, Hye-Lim;Cho, Hye-Kyung
    • The Journal of Korea Robotics Society
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    • v.9 no.3
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    • pp.140-146
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    • 2014
  • This paper introduces a dual-arm robot painter system which is capable of sketching a camera-captured image with short line segments. To express various curved edges in the image by combining line segments, we first apply edge detection algorithm to the entire image, split the edged image into small boxed pieces, and then apply Hough Transformation to each piece so that the edges inside the piece can be approximated with short line segments. To draw the picture within a reasonable time, we designed a simple dual-arm robot system and controlled both arms concurrently according to linear interpolation algorithm. From the experiments, we could verify that simple linear motions can describe various images effectively with a unique brush style.

HEREDITARY PROPERTIES OF CERTAIN IDEALS OF COMPACT OPERATORS

  • Cho, Chong-Man;Lee, Eun-Joo
    • Bulletin of the Korean Mathematical Society
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    • v.41 no.3
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    • pp.457-464
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    • 2004
  • Let X be a Banach space and Z a closed subspace of a Banach space Y. Denote by L(X, Y) the space of all bounded linear operators from X to Y and by K(X, Y) its subspace of compact linear operators. Using Hahn-Banach extension operators corresponding to ideal projections, we prove that if either $X^{**}$ or $Y^{*}$ has the Radon-Nikodym property and K(X, Y) is an M-ideal (resp. an HB-subspace) in L(X, Y), then K(X, Z) is also an M-ideal (resp. HB-subspace) in L(X, Z). If L(X, Y) has property SU instead of being an M-ideal in L(X, Y) in the above, then K(X, Z) also has property SU in L(X, Z). If X is a Banach space such that $X^{*}$ has the metric compact approximation property with adjoint operators, then M-ideal (resp. HB-subspace) property of K(X, Y) in L(X, Y) is inherited to K(X, Z) in L(X, Z).

Realtime control algorithm and hardware for machining curved surfaces (실시간 곡면 가공에 관한 제어 알고리즘 및 하드웨어 연구)

  • 정승권;권욱현
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1320-1323
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    • 1996
  • This paper describes an interpolation method for a parametric surface. A parametric surface is approximated to triangular mesh surfaces and then the basic paths are achieved. As the generated path is a series of linear segments, this algorithm can be easily adapted to general NC controllers. The generated paths have minimal transfer length and are gouge-free within the approximation tolerance. The problems, induced when the paths are represented by linear segments, are overcome without making any path deviation by this algorithm. This algorithm saves machining time by eliminating overdetermined tool paths and keeping the desired average feedrate, which improve productivity and lead to lower production costs.

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Economic Dispatch Algorithm for Unit Commitment (기동정지계획을 위한 경제급전 알고리즘)

  • Park, Jeong-Do;Lee, Yong-Hoon;Kim, Ku-Han;Moon, Young-Hyun
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1506-1509
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    • 1999
  • This paper presents a new economic dispatch algorithm to improve the unit commitment solution while guaranteeing the near optimal solution without reducing calculation speed. The conventional economic dispatch algorithms have the problem that it is not applicable to the unit commitment formulation due to the frequent on/off state changes of units during the unit commitment calculation. Therefore, piecewise linear iterative method have generally been used for economic dispatch algorithm for unit commitment. In that method, the approximation of the generator cost function makes it hard to obtain the optimal economic dispatch solution. In this case, the solution can be improved by introducing a inverse of the incremental cost function. The proposed method is tested with sample system. The results are compared with the conventional piecewise linear iterative method. It is shown that the proposed algorithm yields more accurate and economical solution without calculation speed reduction.

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Power Analysis for Tests Adjusted for Measurement Error

  • Heo, Sun-Yeong;Eltinge, John L.
    • 한국데이터정보과학회:학술대회논문집
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    • 2003.05a
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    • pp.1-14
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    • 2003
  • In man cases, the measurement error variances may be functions of the unknown true values or related covariate. In some cases, the measurement error variances increase in proportion to the value of predictor. This paper develops estimators of the parameters of a linear measurement error variance function under stratified multistage random sampling design and additional conditions. Also, this paper evaluates and compares the power of an asymptotically unbiased test with that of an asymptotically biased test. The proposed method are applied to blood sample measurements from the U.S. Third National Health and Nutrition Examination Survey(NHANES III)

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A Fractional Model Reduction for T-S Fuzzy Systems with State Delay

  • Yoo Seog-Hwan;Choi Byung-Jae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.3
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    • pp.184-189
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    • 2006
  • This paper deals with a fractional model reduction for T-S fuzzy systems with time varying delayed states. A contractive coprime factorization of time delayed T-S fuzzy systems is defined and obtained by solving linear matrix inequalities. Using generalized controllability and observability gramians of the contractive coprime factor, a balanced state space realization of the system is derived. The reduced model will be obtained by truncating states in the balanced realization and an upper bound of model approximation error is also presented. In order to demonstrate efficacy of the suggested method, a numerical example is performed.

EXTRAPOLATED CRANK-NICOLSON APPROXIMATION FOR A LINEAR STEFAN PROBLEM WITH A FORCING TERM

  • Ahn, Min-Jung;Lee, Hyun-Young
    • Journal of applied mathematics & informatics
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    • v.8 no.3
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    • pp.773-793
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    • 2001
  • The explicit expressions for the 2n+1 primitive idempotents in R/sub pⁿ/ = F[x]/< x/sup pⁿ/ -1>, where F is the field of prime power order q and the multiplicative order of q modulo pⁿ is ø(pⁿ)/2(n≥1 and p is an odd prime), are obtained. An algorithm for computing the generating polynomials of the minimal QR cyclic codes of length pⁿ, generated by these primitive idempotents, is given and hence some bounds on the minimum distance of some QR codes of prime length over GF(q)(q=2, 3, ...) are obtained.