• Journal of applied mathematics & informatics
• /
• 제28권3_4호
• /
• pp.913-921
• /
• 2010

The derivative influence measure is adapted to the Cholesky decomposition of a covariance matrix. Formulas for the derivative influence of observations on the Cholesky root and the inverse Cholesky root of a sample covariance matrix are derived. It is easy to implement this influence diagnostic method for practical use. A numerical example is given for illustration.

• 대한수학회보
• /
• 제48권5호
• /
• pp.1093-1103
• /
• 2011

We give the characterizations of the classes of matrix trans-formations ($m(\phi),{\ell}_p$), ($n(\phi),{\ell}_p$) ([5, Theorem 2]), (${\ell}_p,m(\phi)$) ([5, Theorem 1]) and (${\ell}_p,n(\phi)$) for $1{\leq}p{\leq}{\infty}$, establish estimates for the norms of the bounded linear operators defined by those matrix transformations and characterize the corresponding subclasses of compact matrix operators.

• 응용통계연구
• /
• 제26권2호
• /
• pp.361-373
• /
• 2013

군집분석을 위한 알고리즘은 매우 많다. 이러한 군집분석 방법들이 개체들을 어떻게 여러 개의 군집으로 나누는 지를 서로 비교하기 위해서는 나누어지는 군집들이 얼마나 동일한가를 알 수 있는 동의 측도가 필요하다. 우리가 고려하여야 할 군집분석 방법들이 많아질수록 덩달아 동의 측도들 값도 많아지게 된다. 그래서 복수 개의 군집분석 방법들과 대응되는 동의 측도값들을 한 눈에 확인할 수 있는 도구가 필요하다. 본 논문을 통하여 군집분석 방법들과 대응되는 동의 측도값들을 한 눈에 확인할 수 있는 그래픽도구들을 제안하고자 한다.

• 한국소음진동공학회논문집
• /
• 제19권10호
• /
• pp.1021-1027
• /
• 2009

Finite element models of dynamic systems can be updated in two stages. In the first stage, mass and stiffness matrices are updated neglecting damping. In the second stage, a damping matrix is estimated with the mass and stiffness matrices fixed. Methods to estimate a damping matrix for this purpose are proposed in this paper. For a system with proportional damping, a damping matrix is estimated using the modal parameters extracted from the measured responses and the modal matrix calculated from the mass and stiffness matrices from the first stage. For a system with non-proportional damping, a damping matrix is estimated from the impedance matrix which is the inverse of the FRF matrix. Only one low or one column of the FRF matrix is measured, and the remaining FRFs are synthesized to obtain a full FRF matrix. This procedure to obtain a full FRF matrix saves time and effort to measure FRFs.

• 대한수학회논문집
• /
• 제37권1호
• /
• pp.91-103
• /
• 2022

In this paper, we introduce Toeplitz operators and Hankel operators with complex Borel measures on the closed unit disk. When a positive measure 𝜇 on (-1, 1) is a Carleson measure, it is known that the corresponding Hankel matrix is bounded and vice versa. We show that for a positive measure 𝜇 on 𝔻, 𝜇 is a Carleson measure if and only if the Toeplitz operator with symbol 𝜇 is a densely defined bounded linear operator. We also study Hankel operators of Hilbert-Schmidt class.

• 한국정밀공학회지
• /
• 제16권11호
• /
• pp.213-223
• /
• 1999

In this paper, input-output transmission characteristics of the Eclipse, which is a parallel machine tool capable of 5 face rapid machining, are investigated. By splitting the weighted Jacobian matrix into two parts, the force and moment transmission characteristics together with the velocity and angular velocity transmission characteristics are analyzed. A new manipulability measure, which combines the volume of the manipulability ellipsoid and the condition number of the splitted Jcobian matrix, is proposed. Two link parameters, the ratio of upper and lower platforms' radii and the length of a supporting link of the Eclipse, are designed by applying the new manipulability measure derived. Computer simulations are provided.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1693-1696
• /
• 2003

In this paper, input-output velocity transmission characteristics of the Casing Oscillator, which is a constructional machine with 4 degree of freedom are examined. After the Jacobian matrix is decomposed into linear part and angular part, the linear and the angular velocity transmission characteristics are analyzed and visualized in easy way even in the case of 3 dimensional task space with 4 variables. Regarding the measure of dexterity of the Casing Oscillator, the kinematic isotropic index and the manipulability measures which are respectively represented the isotropy and the volume of the manipulability ellipsoid are combined. A performance of the Casing Oscillator is evaluated by the combined manipulability measure.

• 대한기계학회논문집A
• /
• 제28권7호
• /
• pp.904-914
• /
• 2004

In this paper, input-output velocity and force transmission characteristics of the Casing Oscillator which is a construction machine with 4 degrees of freedom are examined. After the Jacobian matrix is decomposed into the linear part and angular part, the velocity and force transmission characteristics for the linear and angular workspace are easily analyzed and visualized even if the Casing Oscillator has the spatial dimensional workspace with 4 DOF. Regarding the manipulability measure of the Casing Oscillator, the kinematic isotropic index and the manipulability measure which represent the isotropy and volume of the manipulability ellipsoid, respectively, are combined to coincidently consider them with respect to equivalent ranges and fluctuations. A performance of the Casing Oscillator is evaluated by the newly proposed manipulability measures.

• Journal of the Korean Statistical Society
• /
• 제21권1호
• /
• pp.59-69
• /
• 1992

A measure is proposed to represent the degree of residuals from the symmetry model for square contingency tables with nominal categories. The measure is derivedby modifying the sum of squared singular values for a skew symmetric matrix of the residuals from the symmetry model. The proposed measure would be useful for comparing the degree of residuals from the symmetry model in several tables.

• Communications for Statistical Applications and Methods
• /
• 제11권1호
• /
• pp.21-30
• /
• 2004

Often the accuracy is not adequate as a performance measure of classifiers when costs are different for different prediction errors. ROC and cost graphs can be used in such case to compare and identify cost-sensitive classifiers. We extend ROC and cost graphs so that they can be used when more general cost matrix is given, where not only misclassifications but correct classifications also incur penalties.