• Title/Summary/Keyword: Wang chong

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Intelligent Algorithm of Harmonic State Estimation for Power System (전력시스템 고조파 상태추정 지능형 알고리즘 개발)

  • Wang Yong P;Lee Hyun J;Chong Hyeng H;Kim Sang H;Park Hee C;Chong Dong I
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.286-288
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    • 2004
  • The design of a measurement system to perform Harmonic State Estimation (HSE) is a very complex problem. In particular, the number of harmonic instruments available is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents a new HSE algorithm which is based on an optimal placement of measurement points using Genetic Algorithms (GAs). This HSE has been applied to the Simulation Test Power System for the validation of the new HSE algorithm. The study results have indicated an economical and effective method for optimal placement of measurement points using Genetic Algorithms (GAs) in the Harmonic State Estimation (HSE).

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A MATRIX INEQUALITY ON SCHUR COMPLEMENTS

  • YANG ZHONG-PENG;CAO CHONG-GUANG;ZHANG XIAN
    • Journal of applied mathematics & informatics
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    • v.18 no.1_2
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    • pp.321-328
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    • 2005
  • We investigate a matrix inequality on Schur complements defined by {1}-generalized inverses, and obtain simultaneously a necessary and sufficient condition under which the inequality turns into an equality. This extends two existing matrix inequalities on Schur complements defined respectively by inverses and Moore-Penrose generalized inverses (see Wang et al. [Lin. Alg. Appl., 302-303(1999)163-172] and Liu and Wang [Lin. Alg. Appl., 293(1999)233-241]). Moreover, the non-uniqueness of $\{1\}$-generalized inverses yields the complicatedness of the extension.

TWO INEQUALITIES INVOLVING HADAMARD PRODUCTS OF POSITIVE SEMI-DEFINITE HERMITIAN MATRICES

  • Cao, Chong-Guang;Yang, Zhong-Peng;Xian Zhang
    • Journal of applied mathematics & informatics
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    • v.10 no.1_2
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    • pp.101-109
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    • 2002
  • We extend two inequalities involving Hadamard Products of Positive definite Hermitian matrices to positive semi-definite Hermitian matrices. Simultaneously, we also show the sufficient conditions for equalities to hold. Moreover, some other matrix inequalities are also obtained. Our results and methods we different from those which are obtained by S. Liu in [J. Math. Anal. Appl. 243:458-463(2000)] and B.-Y Wang et al in [Lin. Alg. Appl. 302-303: 163-172(1999)] .

New Taurine Derivatives from a Starfish and a Sponge

  • Wang, Weihong;Lee, Yoon-Mi;Hong, Jong-Ki;Lee, Chong-Ok;Park, Jong-Hee;Jung, Jee-H.
    • Natural Product Sciences
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    • v.9 no.4
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    • pp.241-244
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    • 2003
  • A new (2) and a known (1) acylated taurine derivatives were isolated from MeOH extract of the starfish Certonardoa semiregularis. Another new acylated taurine derivative (3) was isolated from the MeOH extract of the sponge Erylus nobilis. The structures were determined on the basis of spectral analysis.

A Penalized Principal Components using Probabilistic PCA

  • Park, Chong-Sun;Wang, Morgan
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.05a
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    • pp.151-156
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    • 2003
  • Variable selection algorithm for principal component analysis using penalized likelihood method is proposed. We will adopt a probabilistic principal component idea to utilize likelihood function for the problem and use HARD penalty function to force coefficients of any irrelevant variables for each component to zero. Consistency and sparsity of coefficient estimates will be provided with results of small simulated and illustrative real examples.

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Conservation Laws and Symmetry of Differential Equations -stories about E. Noether's Theorem- (보존률과 미분방정식의 대칭성 -뇌터의 정리를 중심으로-)

  • Han, Chong-Kyu
    • Journal for History of Mathematics
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    • v.31 no.5
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    • pp.211-222
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    • 2018
  • This paper surveys the theory of symmetry group of differential equations. A proof of the simplest version of the Noether's theorem on conservation laws has been presented with examples in the classical mechanics. As a new approach to the conservation laws the theory of characteristic cohomology due to S. H. Wang and others has been presented.