• Title/Summary/Keyword: Multilayered

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Characteristic Analysis of the Asymmetric Coupled microstrip Lines with finite Metalization Thickness in the Multilayered Structure (다층구조에서 도체 두께를 고려한 비대칭 결합선로의 특성해석)

  • 윤남일;홍익표;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.3A
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    • pp.424-429
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    • 2000
  • In this paper, the characteristics of the asymmetric coupled microstrip(ACM) lines with finite metalization thickness are investigated using the quasi-static analysis in the multilayered structure. By mode-matching method as the quasi-static analysis. the characteristic impedances and effective dielectric constants in ACM lines are obtained as a function of metalization thickness. The numerical results show that the propagation characteristics of ACM lines in the single and multilayered structure will be changed by the variation of metalization thickness.

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Analysis of Electromagnetic Shielding Characteristics of the Spherical Multilayered Dielectric (구형 다층 유전체의 전자파 차폐특성 해석)

  • Ryu, Hwang;Lee, Sang-Seul
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.7
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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.

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A Study on the Fabrication and the Properties of Piezoelectric Actuator (압전 액츄에이터의 제작 및 그 특성에 관한 연구)

  • 유동현;한민구;이능헌;김진수;이덕철
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.3
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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.

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Local Response Recovery for Multilayered Composite Panels using Mesh Superposition (유한요소격자중첩을 이용한 복합재료평판의 변위 및 응력의 복원)

  • 박진우;김용협
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.04a
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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.

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A study on the synthesis and mechanical properties of WC/C multilayered films (WC/C 다층박막의 합성 및 기계적 특성에 관한 연구)

  • 명현식;한전건
    • Journal of the Korean institute of surface engineering
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    • v.35 no.3
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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).

A Study of Flow Induced Noise for Multilayered Cylinder due to Turbulent Boundary Layer (난류경계층에 의한 다층재질 원통형 실린더의 유체소음 해석 연구)

  • 신구균;홍진숙;이헌곤
    • Journal of KSNVE
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    • v.6 no.5
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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.

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Electrical Characteristics of Small Scaled Piezoelectric Transformer for PDA Backlight (PDA Backlight용 압전변압기의 전기적 특성)

  • Shin, Hoon-Bum;Kwon, Ju-Nam;Ahn, Hyung-Keun;Han, Deuk-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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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].

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A study on fatigue life of Al 7075/CFRP multilayered hybrid composite materials (Al 7075/CFRP 다적층 하이브리드 복합재료의 피로수명에 대한 연구)

  • 윤한기;김연겸;박준수;이경봉
    • Journal of Ocean Engineering and Technology
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    • v.10 no.4
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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.

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Fabrication of LTCC Tape and Its Microwave Dielectric Properties (LTCC Tape 제조 및 고주파 유전특성 평가)

  • Lee, Kyoung-Ho;Choi, Byung-Hoon;Ahn, Dal;Sung, Jung-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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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.

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A study on interrelation between the structure of a Plant and the str neural network emulator and the learning rate (플랜트구조와 신경망에뮬레이터의 구조 및 학습시간과의 관계)

  • Pae, Chang-Han;Lee, Kwang-Won
    • Proceedings of the KIEE Conference
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    • 1997.07b
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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.

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