• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.180-181
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• 2002

Abstract. A surface plasmon resonance based on a ion-exchange glass waveguide investigated. we analyzed resonant coupling between TM-plarized waveguide mode and surface plasmon wave.

• 전기의세계
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• v.26 no.3
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• pp.73-75
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• 1977

A coupled-mode approach is used to analyze the interaction of the carrier wave in solid-state materials with the external slow electromagnetic wave. A general condition for an active coupling is derived. Gain characteristics is also examined as a function of operating frequency and thermal-to-drift veocity variations.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.185-188
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• 1998

A three-waveguide coupler consisted of a central guide and two side guides is theoretically explored by using modal transmission-line theory. The numerical results reveal that the coupling length Lc is different from that calculated by coupled-mode theory and the difference increases gradually as the guiding modes increase.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.345-346
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.372-373
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.321-322
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• 2008

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.17-24
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• 2014

In this paper, we analysed coupling coefficient between dielectric resonator of high dielectric constant and microstrip line to design for low phase noise dielectric resonator by direct coupling. Also we analysed phase noise of dielectric resonance oscillator with parallel feedback circuit to complement Q by high dielectric constant. We obtained a result from high-stability dielectric oscillator which is optimum designed through analysis of dielectric resonance oscillator phase noise and coupling coefficient. The result is that the phase noise was -83.3dBc/Hz@1KHz at 20.25GHz when we used about 3.6 coupling coefficient and ${\epsilon}_r$=30 dielectric resonator of 20.25GHz dielectric resonance oscillator. As a result, we suggested the direct-connect design method by frequency multiplication mode to prevent phase noise loss at K-Band.

• Coupled systems mechanics
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• v.2 no.3
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• pp.231-253
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• 2013

The impact of spar-nacelle-blade coupling on edgewise dynamic responses of spar-type floating wind turbines (S-FOWT) is investigated in this paper. Currently, this coupling is not considered explicitly by researchers. First of all, a coupled model of edgewise vibration of the S-FOWT considering the aerodynamic properties of the blade, variable mass and stiffness per unit length, gravity, the interactions among the blades, nacelle, spar and mooring system, the hydrodynamic effects, the restoring moment and the buoyancy force is proposed. The aerodynamic loads are combined of a steady wind (including the wind shear) and turbulence. Each blade is modeled as a cantilever beam vibrating in its fundamental mode. The mooring cables are modeled using an extended quasi-static method. The hydrodynamic effects calculated by using Morison's equation and strip theory consist of added mass, fluid inertia and viscous drag forces. The random sea state is simulated by superimposing a number of linear regular waves. The model shows that the vibration of the blades, nacelle, tower, and spar are coupled in all degrees of freedom and in all inertial, dissipative and elastic components. An uncoupled model of the S-FOWT is then formulated in which the blades and the nacelle are not coupled with the spar vibration. A 5MW S-FOWT is analyzed by using the two proposed models. In the no-wave sea, the coupling is found to contribute to spar responses only. When the wave loading is considered, the coupling is significant for the responses of both the nacelle and the spar.

• Tribology and Lubricants
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• v.40 no.1
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• pp.8-16
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• 2024

This study conducts numerical modeling and eigen-analysis of a rod-fastened rotor, which is mainly used in aircraft gas turbine engines in which multiple disks are in contact through curvic coupling. Nayak's theory is adopted to calculate surface parameters measured from the tooth profile of the curvic coupling gear. Surface parameters are important design parameters for predicting the stiffness between contact surfaces. Based on the calculated surface parameters, elastoplastic contact analysis is performed according to the interference between two surfaces based on the Greenwood-Williamson model. The equivalent bending stiffness is predicted based on the shape and elastoplastic contact stiffness of the curvic coupling. An equation of motion of the rod-fastened rotor, including the bending stiffness of the curvic coupling, is developed. Methods for applying the bending stiffness of a curvic coupling to the equation of motion and for modeling the equation of motion of a rotor that includes both inner and outer rotors are introduced. Rotordynamic analysis is performed through one-dimensional finite element analysis, and each element is modeled based on Timoshenko beam theory. Changes in bending stiffness and the resultant critical speed change in accordance with the rod fastening force are predicted, and the corresponding mode shapes are analyzed.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.9
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• pp.50-55
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• 1999

In this paper we proposed a variable optical attenuator using the side polished fiber coupled with a refractive index matching liquid. Small variation of refractive index of matching liquid can induce very large change of optical loss due to the coupling between the fiber mode and radiation mode. The thermo-optic effect of matching liquid was used to ontrol the optical attenuation. The side polished fiber block was fabricated using the silicon V gloove. Experimental results showed that $5^{\circ}C$ temperature variation was enough to adjust full range attenuation. The polarization dependent loss and insertion loss of the fabricated devices were 0.5dB and 0.2dB respectively.