• Korean Journal of Optics and Photonics
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• v.11 no.3
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• pp.179-186
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• 2000

Optical coupling coefficients and misalignment tolerance of 155 Mbps optical transmitter module of passive alignment technology, to be usable in ATM system, B-NT (Broadband Network Termination) system, and 10 G transmission system for information super-highway networks, were calculated, compaired with it's engineer samples, and discussed. These engineer samples of -4.5 dBm maximum output power were packaged in the method of butt coupling of flat-fiber and tested reliability evaluation. Hence the cheap packaging method of optical transmitter module was researched. rched.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.957-959
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• 2014

The wave analysis of cylinders combined rigidly with a finite plate to identify the effect of the plate on the wave propagation. This paper uses the mobility and impedance coupling method to combine a infinite-length cylinder with the plate, and obtains the coupling forces induced by the vibration of the structure. The waveguide finite element method is used to calculate the wave characteristics of the cylinder excited by the forces. From the results, the dispersion diagram can be obtained. It contains the characteristics induced by the vibration and length of the internal plate. It also shows the wave propagation of elastic waves sustained in the cylinder.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.99-103
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• 2012

The electromagnetic topology and the BLT equation has been used as useful techniques to analyze coupling effects of huge devices. But in the case of systems including complex parts, applying the BLT equation can be difficult to manifest the complex parts with analytic solutions. To resolve this problem, a numerical method can be used to parts of the whole system in advance. In this paper, a microstrip line filter is analyzed using the BLT equation combined with numerical solutions. Consequently, achieved graphs from the BLT equation show good agreements with graphs obtained using a numerical method only.

• Interaction and multiscale mechanics
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• v.3 no.2
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• pp.192-211
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• 2010

In most framed structures the nonlinearities and the damages are localized, extending over a limited length of the structural member. In order to capture the details of the local damage, the segments of a member that have entered the nonlinear range may need to be analyzed using the three-dimensional element (3D) model whereas the rest of the member can be analyzed using the simpler one-dimensional (1D) element model with fewer degrees of freedom. An Element-Coupling model was proposed to couple the small scale solid 3D elements with the large scale 1D beam elements. The mixed dimensional coupling is performed imposing the kinematic coupling hypothesis of the 1D model on the interfaces of the 3D model. The analysis results are compared with test results of a reinforced concrete pipe column and a structure consisting of reinforced concrete columns and a steel space truss subjected to static and dynamic loading. This structure is a reduced scale model of a direct air-cooled condenser support platform built in a thermal power plant. The reduction scale for the column as well as for the structure was 1:8. The same structures are also analyzed using 3D solid elements for the entire structure to demonstrate the validity of the Element-Coupling model. A comparison of the accuracy and the computational effort indicates that by the proposed Element-Coupling method the accuracy is almost the same but the computational effort is significantly reduced.

• Korean Journal of Optics and Photonics
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• v.7 no.3
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• pp.207-212
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• 1996

We propose an extended additional layer method (EALM) of calculating the coupling coefficient of arbitrary shaped diffraction gratings. In EALM, to determine the unperturbed field distribtution, a grating region is replaced by a new uniform layer whose dielectric constant is the average value of the dielectric constant of a grating region in both longitudinal and transverse directions. Using this method, we calculate the coupling coefficient for a five-layer distributed feedback structure device with trapezoidal and triangular gratings. The validity of this method is established by comparing the results calculated by partitioning the grating region up to five uniform layers.

• Geomechanics and Engineering
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• v.16 no.1
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• pp.59-69
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• 2018

This study focused on the mechanical and hydraulic characteristics of underwater tunnels based on Mohr-Coulomb (M-C), Hoek-Brown (H-B) and generalized H-B failure criteria. An improved approach for calculating stress, displacement and plastic radius of the circular tunnel considering hydraulic-mechanical coupling was developed. The innovation of this study was that the radius-incremental-approach was reconstructed (i.e., the whole plastic zone is divided into a finite number of concentric annuli by radius), stress and displacement of each annulus were determined in terms of numerical method and Terzaghi's effective stress principle. The validation of the proposed approach was conducted by comparing with the results in Brown and Bray (1982) and Park and Kim (2006). In addition, the Rp-pin curve (plastic radius-internal supporting pressure curve) was obtained using the numerical iterative method, and the plastic radius of the deep-buried tunnel could be obtained by interpolation method in terms of the known value of internal supporting pressure pin. Combining with the theories in Carranza and Fairhurst (2000), the improved technique for assessing the reliability of the tunnel support was proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1177-1182
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• 2006

This paper is concerned with the vibration analysis of a simply-supported rectangular plate with a circular cutout. Even though there have be en many methods developed for the free vibration of the rectangular plate with a rectangular cutout., very few research has been carried out for the rectangular plate with a circular cutout. In this paper, a new methodology called independent coordinate coupling method, which was developed to save the computational effort for the free vibration analysis of rectangular plate with a rectangular cutout, is applied to the case of circular cutout. The independent coordinate coupling method employs the global coordinate system for the plate and the local coordinate system for the cutout. In the case of the rectangular plate with a circular cutout, the global coordinate system is the Cartesian co ordinate system and the local coordinate system is the polar coordinate system. By imposing the compatibility condition, the relationship between the global coordinates and the local coordinates is derived. This equation is then used for the calculation of the mass and stiffness matrices resulting in eigenvalue problem. The numerical results show the efficacy of the proposed method.

• Journal of Magnetics
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• v.18 no.2
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• pp.130-134
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• 2013

Most electrical machines like motor, generator and transformer are symmetric in terms of magnetic field distribution and mechanical structure. In order to analyze these problems effectively, many coupling techniques have been introduced. This paper deals with a coupling scheme for open boundary problem of symmetric and periodic structure. It couples an analytical solution of Fourier series expansion with the standard finite element method. The analytical solution is derived for the magnetic field in the outside of the boundary, and the finite element method is for the magnetic field in the inside with source current and magnetic materials. The main advantage of the proposed method is that it retains sparsity and symmetry of system matrix like the standard FEM and it can also be easily applied to symmetric and periodic problems. Also, unknowns of finite elements at the boundary are coupled with Fourier series coefficients. The boundary conditions are used to derive a coupled system equation expressed in matrix form. The proposed algorithm is validated using a test model of a bush bar for the power supply. And the each result is compared with analytical solution respectively.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.229-234
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• 2005

A novel method to measure the interaction movement, focusing direction and tracking direction in an optical pick-up, is proposed and the decoupling control for it is discussed. First, the basic principle of the coupline analysis method using back electromotive farce is introduced. Second, the interaction analysis between focusing direction and tracking direction fur commercial slim type actuator is performed using the proposed method. Finally, the coupling analysis and decoupling control for the slim type optical pick-up are discussed. From the brief simulation, we shows that the effectiveness and validity of the proposed method.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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• pp.568-577
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• 2000

In this paper for an object grasped by a robot hand to work in stiffness control domain we first investigate the number of fingers for successful stiffness modulation in the object operational space. Next we propose a new compliance control method for robot hands which consist of two steps. RIFDS(Resolved Inter-Finger Decoupling Solver) is to decompose the desired compliance characteristic specified in the op-erational space into the compliance characteristic in the fingertip space without inter-finger coupling and RIJDS(Resolved Inter-Joint Decoupling Solver) is to decompose the fingertip space without inter-finger coupling and RIJDS(Resolved inter-Joint Decoupling Solver) is to decompose the compliance characteristic in the finger-tip space into the compliance characteristic given in the joint space without inter-joint coupling. Based on the analysis results the finger structure should be biominetic in the sense that either kniematic redundancy or force redundancy are required to implement the proposed compliance control scheme, Five-bar fingered robot hands are used as an illustrative example to implement the proposed compliance control method. To show the effectiveness of the proposed compliance control method simulations are performed for two-fingered and three-fingered robot hands.