• International Journal of Precision Engineering and Manufacturing
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• v.3 no.4
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• pp.87-93
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• 2002

In this study, basic concepts of magnet were introduced, and dynamic characteristics of magnet coupling were explored. Based on these characteristics, it was proposed how to analyze transverse and torsional vibrations of a spindle system with magnet coupling. Proposed theoretical approaches were applied to a precision power transmission system machined for this study, and the transverse and torsional vibrations were simulated. The force on magnet coupling was shown as a form of nonlinear function of the gap and the eccentricity. Also, the form of torque transmitted by magnet coupling was considered as a sinusoidal function. Main spindle connected to a coupling of a follower part was assumed to be a rigid body. Nonlinear partial differential equation was derived to be as a function of angular displacement. By using the equation, torsional vibration analysis of a spindle system with magnet coupling was performed. Free and forced vibration analyses of a spindle system with magnetic coupling were explored by using FEM.

• Bulletin of the Korean Chemical Society
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• v.15 no.3
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• pp.228-236
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• 1994

The effect of the vibration mode coupling induced by the vibration-rotation interaction on total energy was investigated for the states with zero total angular momentum(J=0) in a quasilinear symmetric triatomic molecule of $AB_2$ type using a model potential function with a slight potential barrier to linearity. It is found that the coupling energy becomes larger for the levels of bend and asymmetric stretch modes and smaller for symmetric stretch mode as the excitation of the vibrational modes occurs. The results for the real molecule of $CH_2^+$, which is quasilinear, generally agree with the results for the model potential function in that common mode selective dependence of coupling energy is exhibited in both cases. The differences between the results for the model and real potential function in H-C-H system are analyzed and explained in terms of heavy mixing of the symmetric stretch and bend mode in excited vibrational states of the real molecule of $CH_2^+$. It is shown that the vibrational mode coupling in the potential energy function is primarily responsible for the broken nodal structure and chaotic behavior in highly excited levels of $CH_2^+$ for J= 0.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.279-287
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• 2003

This paper deals with a comparative study on coupling of Element-free Galerkin(EFG) method and Infinite Element(IE) by IE's shape function. In this study, mapped infinite elements(mapped IE) and decay function infinite elements(decay IE) are coupled with the EFG method. A coupling procedure of EFG-Mapped IE is much easier to be integrated than a coupled EFG-Decay IE. A coupled EFG-IE method used well-defined functions to preserve the continuity and linear consistency on the interface of the EFG region and IE region. Several benchmark problems are solved to verify the effectiveness and accuracy of the coupling algorithms by IE's shape function. The numerical results show that the developed algorithms work well for the elastic problems with infinite boundaries.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.202-204
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• 2006

A new method is presented to design RF filters without the Similarity Transform of their coupling coefficient matrix as circuit parameters which is very tedious due to pivoting and deciding rotation angles needed during the iterations. The transfer function of a filter is directly used for the design and its desired form is derived by the optimized rational-function fitting technique. A 3rd order Coaxial Lowpass filter and an 8th order dual-mode elliptic integral function response filter are taken as an example to validate the proposed method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.344-347
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• 2000

We analyze the variation of coupling length as a function of the waveguide width for a directional coupler. It is interesting that the coupling length is not monotonic function of waveguide width for a given distance between the centers. The waveguide width for a maximum coupling length can be utilized for the optimum design of a directional coupler.

• Journal of the Korean Mathematical Society
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• v.56 no.4
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• pp.1001-1016
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• 2019

We are concerned with optimization methods for the $L^2$-Wasserstein least squares problem of Gaussian measures (alternatively the n-coupling problem). Based on its equivalent form on the convex cone of positive definite matrices of fixed size and the strict convexity of the variance function, we are able to present an implementable (accelerated) gradient method for finding the unique minimizer. Its global convergence rate analysis is provided according to the derived upper bound of Lipschitz constants of the gradient function.

• Journal of electromagnetic engineering and science
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• v.4 no.3
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• pp.102-106
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• 2004

A novel Genetic Algorithm(GA)-based method is suggested to transform a coupling matrix to another, without the procedure of Matrix Rotation. This can remove tedious work like pivoting and deciding rotation angles needed for each of the iterations. The error function for the GA is simply formed and used as part of error minimization for obtaining the solution. An 8th order dual-mode elliptic integral function response filter is taken as an example to validate the present method.

• Journal of electromagnetic engineering and science
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• v.6 no.3
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• pp.155-159
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• 2006

An efficient method is presented to design filters without the similarity transform of their coupling coefficient matrix as circuit parameters, which is very tedious due to pivoting and deciding rotation angles needed during the iterations. The transfer function of a filter is directly used for the design and its desired form is derived by the optimized rational-function fitting technique. A 3rd order coaxial lowpass filter is taken as an example to validate the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.2
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• pp.149-159
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• 1988

In this paper, the Fourier Transform is employed to solve the coupled differential equations of modal power and three equations of the mode coupling coeficient are dierived using the phasor form trial soluation. The theory of the mode coupling coefficient contains a few theories proposed by earlier authers. Also it is seen that in case the optical source is modulated by a sinusoidal function, this theory is applied as well. In experiment, the mode coupling coefficient is determinded for a multimode graded-index fiber by using the optical source, which modulated by a sinusoidal function.

• Journal of Electrical Engineering and Technology
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• v.5 no.3
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• pp.423-430
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• 2010

Particle swarm optimization (PSO) algorithm is designed to find a single global optimal point. However, the PSO needs to be modified in order to find multiple optimal points of a multimodal function. These modifications usually divide a swarm of particles into multiple subswarms; in turn, these subswarms try to find their own optimal point, resulting in multiple optimal points. In this work, we present a new PSO algorithm, called coupling PSO to find multiple optimal points of a multimodal function based on coupling particles. In the coupling PSO, each main particle may generate a new particle to form a couple, after which the couple searches its own optimal point using non-stop-moving PSO algorithm. We tested the suggested algorithm and other ones, such as clustering PSO and niche PSO, over three analytic functions. The coupling PSO algorithm was also applied to solve a significant benchmark problem, the TEAM workshop problem 22.