• 제목/요약/키워드: Numerical parameter

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폭풍에 의해 발생하는 해빈침식에 대한 수치해석 (Numerical Analysis of Beach Erosion Due to Severe Storms)

  • 조원철;표순보
    • 한국해안해양공학회지
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    • 제12권1호
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    • pp.19-26
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    • 2000
  • 폭풍발생에 따른 해안종단방향의 표시이동은 경빈과 사구의 침식, 연안사주의 생성등 해안단면변화에 있어 주요한 요인의 하나로 알려져 있다. 그러나 폭풍발생에 따른 표사이동은 표사의 입경, 수면상승높이, 쇄파고 등 많은 요소들에 의해 복합적으로 작용하기 때문에 현재에도 정확한 예측이 어려운 실정이다. 본 논문에서는 해안단면에서의 평형에너지소산개념과 표사량 예측에 있어 주요한 요소인 표사량 파라미터를 차원해석을 통하여 변수화하고 수치모델에 도입하여 폭풍발생에 따른 해안종단방향의 해안단면변화와 해빈침식에 대하여 분석하여 보았다. 해안종단방향의 해빈침식은 단면형상 파라미터, 표사량 파라미터, 수면상승높이에 의해 크게 영향을 받음을 알 수 있다.

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감마 일반화 선형 모형에서의 산포 모수 추정량에 대한 효율성 연구 (Comparing the efficiency of dispersion parameter estimators in gamma generalized linear models)

  • 조성일;이우주
    • 응용통계연구
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    • 제30권1호
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    • pp.95-102
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    • 2017
  • 감마 일반화 선형모형은 포아송 분포 또는 이항 분포에 기반한 일반화 선형모형에 비해 적은 관심을 받아왔다. 따라서 감마 일반화 선형모형에서는 오래전에 개발된 통계적인 기법이 아직도 사용되고 있으며, 특히 산포 모수에 대해서는 근사 추정치가 여전히 사용되고 있다. 본 논문에서는 감마 일반화 선형 모형의 산포 모수에 대해 다양한 추정량들을 알아보고 수치 연구를 통해 그들의 효율성을 비교한다. 수치 실험의 결과 최대 가능도 추정량과 Cox-Reid의 수정된 최대 가능도 추정량이 기존의 근사 추정량에 비해 좋은 성능을 보임을 확인하였다.

NEW ALGORITHM FOR THE DETERMINATION OF AN UNKNOWN PARAMETER IN PARABOLIC EQUATIONS

  • Yue, Sufang;Cui, Minggen
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제15권1호
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    • pp.19-34
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    • 2008
  • A new algorithm for the solution of an inverse problem of determining unknown source parameter in a parabolic equation in reproducing kernel space is considered. Numerical experiments are presented to demonstrate the accuracy and the efficiency of the proposed algorithm.

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Smoothing Parameter Selection Using Multifold Cross-Validation in Smoothing Spline Regressions

  • Hong, Changkon;Kim, Choongrak;Yoon, Misuk
    • Communications for Statistical Applications and Methods
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    • 제5권2호
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    • pp.277-285
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    • 1998
  • The smoothing parameter $\lambda$ in smoothing spline regression is usually selected by minimizing cross-validation (CV) or generalized cross-validation (GCV). But, simple CV or GCV is poor candidate for estimating prediction error. We defined MGCV (Multifold Generalized Cross-validation) as a criterion for selecting smoothing parameter in smoothing spline regression. This is a version of cross-validation using $leave-\kappa-out$ method. Some numerical results comparing MGCV and GCV are done.

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개선된 산 클러스터링 방법의 매개변수 설정법 (Identification of the Advanced Mountain Methods parameter)

  • 손세호;권순학;이중우
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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    • pp.125-128
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    • 2000
  • In this paper, we introduce an algorithm for identification of the Advanced Mountain Methods parameter. It consists of two phases: Phase I and Phase II. In Phase I, a given data space is divided into subspaces based on the density of the given data. In Phase II, we obtain the AMMs parameter $\omega$ by selecting the minimum of variances of subspaces obtained in Phase I. Numerical examples are presented to show the validity of the proposed method.

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NUMERICAL STUDY FOR THE PARAMETER ESTIMATION OF THE MOISTURE TRANSFER COEFFICIENT : 2D CASE

  • Lee, Yong-Hun;Park, Yeon-Hee
    • Journal of applied mathematics & informatics
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    • 제29권5_6호
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    • pp.1257-1268
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    • 2011
  • The thermal behavior of wood exposed to the outdoors is influenced by solar absorptivity and longwave emissivity. However, it is difficult to measure that properties directly. Hence we estimate the values of the parameter by using the least-square optimization technique. Finally we report the results for the computation of the values of the parameters.

PARAMETER ESTIMATION PROBLEM FOR NONHYSTERETIC INFILTRATION IN SOIL

  • CHO, CHUNG-KI;KANG, SUNGKWON;KWON, YONGHOON
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제4권1호
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    • pp.11-22
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    • 2000
  • Nonhysteretic infiltration in nonswelling soil is modelled by the Burgers equation under appropriate physical conditions. For this nonlinear partial differential equation the modal approximation scheme is used for estimating parameters such as soil water diffusivity and hydraulic conductivity. The parameter estimation convergence is proved, and numerical experiments are performed.

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

  • 노철언
    • 한국진공학회지
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    • 제5권2호
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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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Fault Diagnosis for Parameter Change Fault

  • Suzuki, Keita;Fujii, Takao
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.2183-2187
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    • 2005
  • In this paper we propose a new fault detection and isolation (FDI) method for those faults of parameter change type. First, we design a residual generator based on the ${\delta}$-operator model of the plant by using the stable pseudo inverse system. Second, the parameter change is estimated by using the property of the block Hankel operator. Third, reliability with respect to stability is quantified. Fourth, the limitations for the meaningful diagnosis in our method are given. The numerical examples demonstrate the effectiveness of the proposed method.

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Robust stabilization of plants with both parameter perturbation and unstructured uncertainty

  • Shen, Tielong;Tamura, Katsutoshi
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.586-591
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    • 1992
  • In this paper a robust stabilization problem is discussed for plant with both time-varying parameter perturbations and unstructured uncertainty. It is shown that, a robust L$_{2}$-stabilizing controller can be obtained by solving an H$_{\infty}$ standard problem with a scaling parameter. Using an H$_{\infty}$ design method, a robust L$_{2}$-stabilizing controller is derived. Finally, a numerical example is given.n.

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