• 한국통신학회논문지
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• 제25권3A호
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• pp.424-429
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• 2000

본 논문에서는 준정적 해석방법을 사용하여 다층 구조에서 유한한 도체 두께를 갖는 비대칭결합 마이크로스트립(ACM: Asymmetric Couple Microstrip) 선로의 특성을 연구하였다. 준정적 해석방법으로서 모드정합법을 이용하였으며, ACM 선로의 특성 임피던스와 유효 유전율 상수가 도체 두께의 함수로 나타나는 결과를 얻었다. 수치해석 결과를 통해서 단층 및 다층구조에서 도체 두께의 변화로 인하여 ACM 선로의 전파특성이 변화되는 것으로 나타났다.

• 전자공학회논문지A
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• 제30A권7호
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• pp.26-31
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• 1993

We have analyzed shielding characteristics of the spherical multilayered dielectric, with the assumption that the inner part of the model is filled with the perfect conductor whose radius is varied from 0.2.lambda. to 1.0.lambda. and the outer part of the conducting sphere is covered by a lossy multilayered dielectric. Variation of shielding effects have been examined as the function of parameter of the dielectric layer and the radius of the conducting sphere.

• 전자공학회논문지A
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• 제31A권3호
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• pp.10-18
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• 1994

In this paper, the single round type and the multilayered type actuator using PZT powders were manufactured and their piezoelectric, displacement and time response characteristics were investigated. In the single round type actuator, the piezoelectric coefficient and the displacement increased with sintering temperature. In the multilayered actuator, the piezoelectric coefficient and the displacement increased with the layered number. In ten layered case, the piezoelectric coefficient and the displacement were higher over three times and six times than those of the single round type, respectively. At the voltage applied, the response velocity of the multilayered type was higher over two times than that of the single round type.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.89-92
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• 2000

In this paper, an effective procedure is presented for the local recovery of displacements and stresses in multilayered composite panels, which incorporate the local refinement using mesh superposition. The mesh superposition method is used to refine the global coarse mesh by superimposing refined mesh to the localized zone of interest without transition zones. The finite element model used is a solid element based on the Hellinger-Reissner variational principle. The a posteriori computation of the through-the-thickness distributions of displacements and stresses is achieved using a predictor-corrector procedure. The procedure utilizes the superconvergent stresses and nodal displacements of the finite element patch. The element patch is generated by locally superimposing a refined local mesh to the coarse global mesh.

• 한국표면공학회지
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• 제35권3호
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• pp.121-126
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• 2002

WC/C multilayered films were deposited by arc ion plating and magnetron sputter hybrid system with various $C_2$H$_2$ flow rates and bias voltages. The coatings have been characterized with respect to their chemical composition (Glow Discharge Optical Emission Spectroscopy), hardness(Knoop micro-hardness), residual stress(Laser beam bending) and friction coefficient(Ball on disc type wear test). Deposition rate, microhardness and residual stress of WC/C films were observed to increase with increasing the $C_2$$H_2$ flow rates. The highest hardness and residual stress were measured to be 26.5 GPa and 1.1GPa for, WC/C film deposited at substrate bias of -100V. WC/C multilayered film was obtained very low friction coefficient(~0.1).

• 소음진동
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• 제6권5호
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• pp.671-677
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• 1996

This paper presents the analytical method for predicting turbulence- induced noise in the multilayered cylinder composed of an outer hose, an inner fluid and an internal core. It is assumed that an infinite axisymmetric cylinder is located horizontally in water with free stream velocity and the turbulent boundary layer (TBL) surrounding the outer hose is fully developed and homogeneous. The transfer function at the core surface due to the propagation of the pressure fluctuation within the TBL is formulated using the linearized Navier-Stockes equation for solid and fluid. In the estimation of the energy spectrum of wall pressure fluctuation, the empirical formula proposed by Strawderman based on the Corcos model is used. A general algorithm for the calculation of the pressure level at the surface of a core, that is, turbulence- induced noise, is presented. Through the detailed numerical simulation, it is found that the major noise mechanism is the propagation of the bulge wave along hose.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.644-647
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• 2003

In this paper, Small scaled multilayered piezoelectric transformer of Rosen type has been fabricated and tested for the purpose of PDA backlight. Turn on characteristics of PDA backlight has been traced with different voltages. $22{\times}4.5{\times}1.1[mm^3]$ multilayered transformer shows full turn-on behavior starting from 4.3[V].

• 한국해양공학회지
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• 제10권4호
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• pp.92-102
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• 1996

In this research, to develope the A1 7075/CFRP multilayered hybrid composites, CRALL(Carbon Reinforced aluminum lamiate) specimens were processed by autoclavecuring system that curing temperature, time, surface pretreatment condition of aluminum were constant. Andthe fatigye life and failure mechanism on CFRP volume fraction and fiber orientation of CRALLspecimens were investigated. A fatigue life was greatly influenced by effect of CFRP fiber volume fraction but it was less effected than those of fiber orientation. The fatigue failure arised from interface delamination of CFRP and aluminum sheet after shear fracture of aluminum layer. The failure mechanism is assumed that the aluminum laminates which divide the CFRP into many thim layers tend to arrest the failure propagation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.382-385
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• 2001

In the previous study, a new LTCC material in the $PbWO_{4}-TiO_{2}-B_{2}O_{3}-CuO$ system was introduced. The developed material can be sintered at $850^{\circ}C$ and its dielectric properties are $\varepsilon_{r}=20-25$, $Q{\times}f_{o}=30000\sim50000GHz$, and $\tau_{f}=0.2{\sim}30ppm/^{\circ}C$, respectively. Therefore this material can be used as a LTCC substrate material for fabrication of multilayered high frequency communication module set. In present study, using this material, tape casting condition was established. With this condition, a multilayered resonator was fabricated and its electrical properties were examined. In present study, an antenna-duplexer module was also fabricated. Frequency characteristics of as-fabricated antenna-duplexer module was compared with simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.386-389
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• 1997

Error-backpropagation has been used in the bulk of Practical applications for neural networks. While an emulator, a multilayered neural network, learns to identify the system's dynamic characteristics. There is, however, no concrete theoretical results about the structure of a plant and the structure of a multilayered neural network and the learning rate. The paper investigates the relation between structure of a plant and a multilayered network and learning rate. Simulation study shows that the plant signal with a short period and a fast sam time is preferable for learning of the network emulator.