• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.10a
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• pp.63-68
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• 1991

The frequency window method has been extended to include strong coupling and multiple connections between the primary structure and the secondary structures. The rational polynomial expansion of the eigenvalue problem and the analytical methods for its solution are novel and distinguish this work from other eigenvalue analysis methods. The key results are the identification of parameters which quantify the resonance and coupling characteristics; the derivation of analytical dosed-form expressions describing the fundamental modal properties of the frequency windows; and the development of an iterative procedure which yields accurate convergent results for strongly-coupled primary-secondary structures.

• Communications for Statistical Applications and Methods
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• v.14 no.1
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• pp.215-227
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• 2007

Variable selection algorithm for Sliced Inverse Regression using penalty function is proposed. We noted SIR models can be expressed as generalized eigenvalue decompositions and incorporated penalty functions on them. We found from small simulation that the HARD penalty function seems to be the best in preserving original directions compared with other well-known penalty functions. Also it turned out to be effective in forcing coefficient estimates zero for irrelevant predictors in regression analysis. Results from illustrative examples of simulated and real data sets will be provided.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.180-185
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• 2013

A new formulation of the MNDIF method is introduced to extract highly accurate natural frequencies of concave plates with arbitrary shape. Originally, the MNDIF method cannot yield accurate natural frequencies for concave plates. To overcome this weak point, a new approach of dividing a concave plate into two convex domains is proposed and the validity and accuracy is shown in a verification example.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.54-56
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• 1993

A systematic procedure for determining the elements of system state matrix is suggested. The interrelation of submatrices of the system matrix is investigated. Each element or each block can be represented in algebraic form. These results can be applied in the eigenvalue sensitivity analysis with respect to the changes in controller parameters.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.658-663
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• 2013

A new formulation of the MNDIF method is introduced to extract highly accurate eigenvalues of concave acoustic cavities with arbitrary shapes. It is said that the MNDIF method cannot yield accurate eigenvalues for concave cavities. To overcome this weak point, a new approach of dividing a concave cavity into two convex domains is proposed. The validity of the proposed method is shown through a case study.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.5 no.2
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• pp.17-23
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• 2001

The evaluation of a few of the smallest eigenpairs of large symmetric eigenvalue problem is of great interest in many physical and engineering applications. A deflation-preconditioned conjugate gradient(PCG) scheme for a such problem has been shown to be very efficient. In the present paper we provide the numerical stability of a deflation-PCG with partial shifts.

• Steel and Composite Structures
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• v.50 no.2
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• pp.123-133
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• 2024

The paper deals with the propagation of Rayleigh waves in a nonlocal thermoelastic isotropic layer which is lying over a nonlocal thermoelastic isotropic half-space under the purview of Green-Lindsay model and Eringen's nonlocal elasticity in the presence of voids. The normal mode analysis is employed to the considered equations to obtain vector matrix differential equation which is then solved by eigenvalue approach. The frequency equation of Rayleigh waves is derived and different particular cases are also deduced. The effects of voids and nonlocality on different characteristics of Rayleigh waves are presented graphically.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.5
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• pp.241-249
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• 2003

This paper describes a novel approach for performing eigenvalue analysis and frequency domain analysis of multi-machine power system. The salient feature of this approach is a direct approach for constructing the state matrix equations of linearized power systems about its operating point using modular technique. These state matrix equations are then used to obtain eigenvalues and mode shapes of the system, and frequency response, or Bode, plots of selected transfer functions. The proposed program provides a flexible tool for systematic analyses of tuning PSS's parameters. The paper also presents its application to the analyses of a single-machine infinite bus system and two-area system with 4 machines.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.753-756
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• 2002

In this study, it is attempted to obtain the optimum size of holes in 15 square plate models where a hole exists on every quadrant of a plate, and to get eigenvalues by performing free vibration analysis far each model. Moreover, the specimen is produced from optimized square plate and eigenvalue of each plate is measured through the shocking load. And then the result is compared with that of finite element analysis. For free vibration analysis of the square plate, the boundary condition of finite element analysis and experiment is assumed as both ends support. From the results of this study, it is known that more stable structures can be designed by changing the natural frequency which is dependent on the location of holes and further studies are considered to be necessary for the basic design information.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.132-139
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• 2003

In this study, it is attempted to obtain the optimum size of holes in 15 square plate models where a hole exists on every quadrant of a plate, and to get eigenvalues by performing free vibration analysis for each model. Moreover, the specimen is produced from optimized square plate and eigenvalue of each plate is measured through the shocking load. And then the result is compared with that of finite element analysis. For free vibration analysis of the square plate, the boundary condition of finite element analysis and experiment is assumed as both ends clamped support. From the results of this study, it is known that more stable structures can be designed by changing the natural frequency which is dependent on the location of holes and further studies are considered to be necessary fur the basic design information.