• 제목/요약/키워드: matrix geometric mean

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EXTENSION OF BLOCK MATRIX REPRESENTATION OF THE GEOMETRIC MEAN

  • Choi, Hana;Choi, Hayoung;Kim, Sejong;Lee, Hosoo
    • 대한수학회지
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    • 제57권3호
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    • pp.641-653
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    • 2020
  • To extend the well-known extremal characterization of the geometric mean of two n × n positive definite matrices A and B, we solve the following problem: $${\max}\{X:X=X^*,\;\(\array{A&V&X\\V&B&W\\X&W&C}\){\geq}0\}$$. We find an explicit expression of the maximum value with respect to the matrix geometric mean of Schur complements.

Weighted Carlson Mean of Positive Definite Matrices

  • Lee, Hosoo
    • Kyungpook Mathematical Journal
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    • 제53권3호
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    • pp.479-495
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    • 2013
  • Taking the weighted geometric mean [11] on the cone of positive definite matrix, we propose an iterative mean algorithm involving weighted arithmetic and geometric means of $n$-positive definite matrices which is a weighted version of Carlson mean presented by Lee and Lim [13]. We show that each sequence of the weigthed Carlson iterative mean algorithm has a common limit and the common limit of satisfies weighted multidimensional versions of all properties like permutation symmetry, concavity, monotonicity, homogeneity, congruence invariancy, duality, mean inequalities.

THE k-GOLDEN MEAN OF TWO POSITIVE NUMBERS AND ITS APPLICATIONS

  • Choi, Jin Ho;Kim, Young Ho
    • 대한수학회보
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    • 제56권2호
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    • pp.521-533
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    • 2019
  • In this paper, we define a mean of two positive numbers called the k-golden mean and study some properties of it. Especially, we show that the 2-golden mean refines the harmonic and the geometric means. As an application, we define the k-golden ratio and give some properties of it as an generalization of the golden ratio. Furthermore, we define the matrix k-golden mean of two positive-definite matrices and give some properties of it. This is an improvement of Lim's results [2] for which the matrix golden mean.

그레디언트 행렬 고유치의 기하 평균을 이용한 특징점 검출 (Feature Detection using Geometric Mean of Eigenvalues of Gradient Matrix)

  • 예철수
    • 대한원격탐사학회지
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    • 제30권6호
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    • pp.769-776
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    • 2014
  • 동일 대상에 대한 두 영상의 등록을 위해서는 두 영상에 공통적으로 존재하는 특징점을 검출하고 검출된 특징점 간의 대응관계를 찾는 과정이 필수적이다. 본 논문에서는 화소의 밝기 변화를 측정할 수 있는 그레디언트 행렬의 고유치 기하평균에 기반한 새로운 특징점 검출기를 제안한다. 제안하는 특징점 검출기는 그레디언트 행렬의 두 고유치의 기하평균 크기에 비례하고 기하 평균 크기가 동일한 경유 두 고유치의 상대적인 차이에 비례하여 가변적으로 변하는 특성을 가진다. 제안한 특징점 검출기의 성능 평가를 위해 다양한 종류의 코너가 존재하는 합성 영상과 항공 영상을 기준 영상으로 사용하여 코너 검출의 위치 오차를 분석하였다. 제안한 검출기의 위치 오차는 Gaussian smoothing scale 조건하에서 대표적인 코너 검출기인 Harris detector의 위치 오차보다 작은 결과가 얻어졌다.

Metric and Spectral Geometric Means on Symmetric Cones

  • Lee, Hosoo;Lim, Yongdo
    • Kyungpook Mathematical Journal
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    • 제47권1호
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    • pp.133-150
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    • 2007
  • In a development of efficient primal-dual interior-points algorithms for self-scaled convex programming problems, one of the important properties of such cones is the existence and uniqueness of "scaling points". In this paper through the identification of scaling points with the notion of "(metric) geometric means" on symmetric cones, we extend several well-known matrix inequalities (the classical L$\ddot{o}$wner-Heinz inequality, Ando inequality, Jensen inequality, Furuta inequality) to symmetric cones. We also develop a theory of spectral geometric means on symmetric cones which has recently appeared in matrix theory and in the linear monotone complementarity problem for domains associated to symmetric cones. We derive Nesterov-Todd inequality using the spectral property of spectral geometric means on symmetric cones.

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A Score test for Detection of Outliers in Nonlinear Regression

  • Kahng, Myung-Wook
    • Journal of the Korean Statistical Society
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    • 제22권2호
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    • pp.201-208
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    • 1993
  • Given the specific mean shift outlier model, the score test for multiple outliers in nonlinear regression is discussed as an alternative to the likelihood ratio test. The geometric interpretation of the score statistic is also presented.

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Stationary random response analysis of linear fuzzy truss

  • Ma, J.;Chen, J.J.;Gao, W.;Zhao, Y.Y.
    • Structural Engineering and Mechanics
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    • 제22권4호
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    • pp.469-481
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    • 2006
  • A new method called fuzzy factor method for the stationary stochastic response analysis of fuzzy truss with global fuzzy structural parameters is presented in this paper. Considering the fuzziness of the structural physical parameters and geometric dimensions simultaneously, the fuzzy correlation function matrix of structural displacement response in time domain is derived by using the fuzzy factor method and the optimization method, the fuzzy mean square values of the structural displacement and stress response in the frequency domain are then developed with the fuzzy factor method. The influences of the fuzziness of structural parameters on the fuzziness of mean square values of the displacement and stress response are inspected via an example and some important conclusions are obtained. Finally, the example is simulated by Monte-Carlo method and the results of the two methods are close, which verified the feasibility of the method given in this paper.

POSITIVENESS FOR THE RIEMANNIAN GEODESIC BLOCK MATRIX

  • Hwang, Jinmi;Kim, Sejong
    • 대한수학회논문집
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    • 제35권3호
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    • pp.917-925
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    • 2020
  • It has been shown that the geometric mean A#B of positive definite Hermitian matrices A and B is the maximal element X of Hermitian matrices such that $$\(\array{A&X\\X&B}\)$$ is positive semi-definite. As an extension of this result for the 2 × 2 block matrix, we consider in this article the block matrix [[A#wijB]] whose (i, j) block is given by the Riemannian geodesics of positive definite Hermitian matrices A and B, where wij ∈ ℝ for all 1 ≤ i, j ≤ m. Under certain assumption of the Loewner order for A and B, we establish the equivalent condition for the parameter matrix ω = [wij] such that the block matrix [[A#wijB]] is positive semi-definite.

Compatibility를 이용한 다수 전문가의 가중치 종합화에 관한 연구 (A Study on the Aggregation of Multi-Experts Priorities Using Compatibility in the AHP)

  • 조성훈;김태성;이영찬
    • 한국경영과학회지
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    • 제23권4호
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    • pp.131-140
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    • 1998
  • The objective of this study is to propose a new procedure to synthesize the multi-experts priorities in AHP. If multi-experts with different expertise are involved in a AHP decision, we need some way to aggregate their opinions. AHP model used to do numerical aggregation by taking only the geometric mean or the weighting geometric mean in past. To aggregate the multi-experts priorities, In this paper. we suggest a way which Decision Maker can exclude outlier matrix from group using the concept of the Compatibility and we Introduce Delphi method to use Compatibility in AHP. A numerical example is shown to illustrate the procedure.

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