• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.8
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• pp.958-964
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• 1999

The distance in load parameter space to the closest saddle node bifurcation (CSNB) point provides the worst case power margin to voltage instability and the left eigenvector at CSNB identifies the most effective direction to steer the system to maximize voltage stability under contingency. This paper presents an improved direct method for computing CSNB: the order of nonlinear systems equations is reduced to about twice of the size of load flow equations in contrast to about three-times in Dobson's direct method; the initial guess for the direct method is computed efficiently and robustly by combined use of continuation power flow, a pair of multiple load flow solution with Lagrange interpolation. It is also shown that voltage stability may be enhanced significantly with shift of generations in the direction of the left eigenvector at CSNB.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.129-139
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• 2000

The problem of eigenvalue and eigenvector is obtained from a V-notched crack in pseudo-isotropic dissimilar materials by the traction free boundary and the perfect bonded interface conditions. The complex stress function is assumed as the two-term William's type. The eigenvalue is solved by a commercial numerical program, MATHEMATICA to discuss stress singularities for V-notched cracks in pseudo-isotropic dissimilar materials. The RWCIM(Reciprocal Work Contour Integral Method) is applied to the determination to eigenvector coefficients associated with eigenvalues. The RWCIM algorithm is also coded by the MATHEMATICA.

• Communications of the Korean Mathematical Society
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• v.32 no.1
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• pp.215-224
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• 2017

In this paper, we propose a method of order two for the computation of positive solutions to a boundary value problem of the linear beam equation. The method is based on the Power method for the eigenvector associated with the dominant eigenvalue and the Crout-like factorization algorithm for the banded system of linear equations. It is extremely fast due to the linear complexity of the linear system solver. Numerical result of a test problem is included.

• Journal of the Korean Data and Information Science Society
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• v.3 no.1
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• pp.33-46
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• 1992

The set of eigenvectors of the second moment matrix and the mean vector are the measures of orientation for a distribution supported on the unit sphere. Bootstrap confidence cone for the eigenvector is constructed and the consistency of this method is discussed. The performance of our bootstrap cone for the eigenvector is compared with that of the asymptotic confidence cones for two measures under the parametric assumptions for the underlying distributions and that of the bootstrap cone for the mean vector by Monte Carlo simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.3
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• pp.515-523
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• 1997

A high resolution algorithm is presented for resolving multiple coherent spread spectrum signals that are incident on an equispaced linear array. Unlike the conventional noise-eigenvector based methods, this algorithm makes use of the signal eigenvectors of the array spectral density matrix that are associates with eigenvalues that are larger than the sensor noise level. Simulation results are shown to demonstate the high performance of the proposed approach in comparison with MUSIC in which coherent signal subspace method (CSM) is employed.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.319-321
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• 1994

When a few eigenvalues and eigenvectors are desired, Rayleigh Quotient Iteration(RQI) is widely used. The ROI, however, cannot give maximum or minimum eigenvalue/eigenvector. In this paper, Modified Rayleigh quotient Iteration(MRQI) is developed. The MRQI can give the maximum or minimum eigenvalue/eigenvector regardless of tile initial starting vector.

• Honam Mathematical Journal
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• v.44 no.2
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• pp.195-208
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• 2022

In this article, the matrix representation of commutative elliptic octonions and their properties are described. Firstly, definitions and theorems are given for the commutative elliptic octonion matrices using the elliptic quaternion matrices. Then the adjoint matrix, eigenvalue and eigenvector of the commutative elliptic octonions are investigated. Finally, α = -1 for the Gershgorin Theorem is proved using eigenvalue and eigenvector of the commutative elliptic octonion matrix.

• The Journal of the Acoustical Society of Korea
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• v.25 no.1
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• pp.36-42
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• 2006

A Principal component analysis (PCA)-based Mel-Frequency Discrete Wavelet Coefficients (MFDWC) feature Parameters for speaker verification system is Presented in this Paper In this method, we used the 1st-eigenvector obtained from PCA to calculate the energy of each node of level that was approximated by. met-scale. This eigenvector satisfies the constraint of general weighting function that the squared sum of each component of weighting function is unity and is considered to represent speaker's characteristic closely because the 1st-eigenvector of each speaker is fairly different from the others. For verification. we used Universal Background Model (UBM) approach that compares claimed speaker s model with UBM on frame-level. We performed experiments to test the effectiveness of PCA-based parameter and found that our Proposed Parameters could obtain improved average Performance of $0.80\%$compared to MFCC. $5.14\%$ to LPCC and 6.69 to existing MFDWC.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.23-32
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• 1998

A shape estimation is needed to control actively a smart structure. A method is, hence, proposed to predict the deformed shape of the structure subjected to unknown external load using the signal from sensors attached to the structure. The shape estimation is based on the relationship between the deformation of the structure and the signal from the sensors. The matrix containing the relationship between the deformation and signal is obtained using fictitious force or eigenvector of global stiffness matrix. Then the deformed shape can be predicted using the linear matrix and signal from sensors attached to the structure. To verify this method, experiment and FEM were performed and it was shown that the shape estimation method based on the fictitious force predicts deflections well and more accurately than that based on eigenvector.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.2
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• pp.179-194
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• 2009

The spatial distribution of crime incidences in urban neighborhoods is a reflection of their socio-economic environment and spatial inter-relations. Spatial interactions between offenders and victims lead to spatial autocorrelation of the crime incidences. The spatial autocorrelation among the incidences biases the interpretation of the ecological model in OLS framework. This research investigates residential crimes using residential burglaries and robberies occurred in the city of Columbus, Ohio, for 2000. In particular, the spatial distribution of incidence rates of residential crimes are accounted in OLS framework using eigenvectors, which reflect spatial dependence in crime patterns. Result presents that handling spatial autocorrelation enhanced model estimation, and both economic deprivation and crime opportunity are turned out significant in estimating residential crime rates.