• Title/Summary/Keyword: Line Element

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A Study on $90^{\cire}$ Constant Phase Shifter (전송선형 $90^{\cire}$ 정위상기에 관한 연구)

  • 이충웅
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.13 no.6
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    • pp.12-15
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    • 1976
  • This paper presents the realization method of 90$^{\circ}$ constant phase shifter in the VHF band, constructed by the entirely differens idea from the conventional method of the realization of constant phase shifter in the audio frequency range. The construction of 90$^{\circ}$ constant phase shifter is. simple and can be easily realized by using the distributed constant element, transmission line, and the lumped constant elements, R,C,L.

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Comparison of Dynamic Characteristics of the tine Start Permanent Magnet Motor and the Induction Motor

  • Yang, Byoung-Yull;Kwon, Byung-Il;Lee, Chul-Kyu;Woo, Kyung-Il;Kim, Byung-Taek
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.2B no.3
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    • pp.90-94
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    • 2002
  • The line start permanent magnet (LSPM) motor has been developed facilitate to the design of the synchronous motor. The rotor of this motor is composed of interior permanent magnets and aluminum bars instead of rotor windings. It is difficult to predict the performance characteristics accurately, because many characteristics are produced by the aluminum rotor bars and the permanent magnets. Therefore, in this paper the dynamic characteristics of the LSPM motor are described and compared via the time-stepped finite element method with those of the cage-type induction motor to find the characteristics of the permanent magnets and the rotor bars in the LSPM motor.

Plane Strain Analysis of Sheet Metal with Arbitrary Forming Conditions (임의의 성형조건을 갖는 박판의 평면변형율 해석)

  • Keum, Y.T.;Lee, S.Y.;Wagoner, R.H.
    • Transactions of Materials Processing
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    • v.1 no.1
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    • pp.95-103
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    • 1992
  • The plane strain analysis for simulating the stretch/draw forming operation with an arbitrarily-shaped tool profile is introduced. An implicit, incremental, updated Lagrangian formulation with a rigid-viscoplastic constitutive equation is employed. Contact and friction are considered through the mesh-normal, which compatibly describes arbitrary tool surfaces and FEM meshes without depending on the explicit spatial derivatives of tool surfaces. The linear line elements are used for depicting the formed sheet, based on membrane approximation. The FEM formulation is tested in the sections of automotive inner panel and two-side draw-in. Not only the excellent agreement between measured and computed strains is obtained in the stretched section, but also the numerical stability of formulation is verified in the draw-in section.

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Structural Design of Door Assembly to Apply Tailor Welded Blanks Technique (합체박판 성형기법의 적용을 위한 자동차 도어의 구조 설계)

  • 황우석;이덕영;하명수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.228-233
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    • 2002
  • TWB(Tailor Welded Blanks) is one of the recent techniques to reduce the weight and cost of the body members. To apply the TWB technique, we must decide the position of the welding line and the thickness of the welded blanks. Although many researchers have tried to check the formability of welded blanks, there are not so many researches from the structural point of view. In this paper, the TWB technique is applied to combine the door inner panel and the hinge face panel into one piece. The finite element structural analysis of the door assembly leads to the final design of the tailor welded door inner panel, which shows the mass reduction of 1.08kg without the sacrifice of the structural stiffness. The structural stiffness analysis includes the frame stiffness analysis, the belt line stiffness analysis, the door sagging analysis and the vibration analysis.

Simulation of Line Heating Process by Finite Element Analysis (유한요소해석에 의한 선상가열 변형의 시뮬레이션)

  • I.S. Nho;J.G. Shin;K.H. Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.2
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    • pp.75-83
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    • 1995
  • As a basic research for the automation of plate forming process, the theoretical aspect of plate bending by line heating was surveyed and numerical simulation of plate bonding deformation was performed using the 3-dimensional nonlinear transient thermal elasto-plastic finite element analysis. Analyzing the unsteady heat conduction problem of the flat steel plate under heat flux input by gas torch, the time history of 3-dimensional thermal distribution was obtained. Transient thermal deformation process of the plate was analyzed under the thermal loading. And the calculated results are investigated in detail.

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Distribution of Strain Types and Function of P Transposable Element in Natural Populations of Drosophila melanogaster (초파리 자연집단의 P 전이인자에 대한 계통형 분포와 기능에 관한 연구)

  • 김지식;권도형추종길
    • The Korean Journal of Zoology
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    • v.38 no.2
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    • pp.177-185
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    • 1995
  • 두 지역에서 채집한 초파리 자연집단에 대하여 난소발생이상 실험에 의한 P 인자 활성과 세포질형을 분석하여 P 전이인자의 계통형을 조사하였다 전체 238 isofemale line을 조사한 결과 strong P와 true M은 존재하지 않았고, 0(weak P)와 M'(pseudo M) strain이 전체의 98.74%를 차지하여 가장 우세하게 분포하고 있었다. P$\pi$25.1 probe를 이용한 in situ hybridization을 행하여 P 전이인자의 copy수를 조사한 결과 평균 42.12개로 나타났으며, 0와 M'의 계통형 간에 유의적인 차이는 없었다 그러나 염색체 firm당 COPy수는 X염색체가 상염색체의 좌 우 각 arm보다 다소 높게 분포하고 있었고. 염색체상 P 전이인자의 삽입부위에 대한 특이적 좌위는 존재하지 않았다 P 전이인자의 분자구조에 대한 변이형을 조사하기 위하여 southern blot hybridization을 행한 결과 2.9kb의 완전한 크기의 분자를 포함하여 여러종류의 단편들이 확인되었다 조사한 모든 isofemale line에서 KP(1. 15kb)인자를 포함하고 있었으며 이들 KP인자가 P-M System의 난소발생이상을 표현하는데 있어 억제적 작용을 하는 것으로 판단되었다.

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Welding Distortion Analysis of a Laser Welded Thin Box Structure (얇은 박스형 용접구조물의 용접변형 해석)

  • Kim, Choong-Gi;Kim, Jae-Woong;Kim, Kim-Chul
    • Journal of Welding and Joining
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    • v.25 no.5
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    • pp.72-77
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    • 2007
  • Prediction and control of the thermal distortion is particularly important for the design and manufacture of welded thin metal structure. In this study, numerical computations are performed to analyze effect of structure section shape and weld line location on distortion. In addition, this study aims to develop a thermal elasto-plastic simulation using finite element method to predict distortion, with particular emphasis on bending deformation generated in outline welding of a thin box structure. From the numerical analysis, it was revealed that the section shape and weld line location play an important role on the welding distortion. Among 3 types of section shape design proposed in this study, the least deformation remained in the two path welded structure.

Analysis of characteristics for clamping voltage fellowing the application of element for preventing the short circuit of Metal Oxide Varistors for ZnO (ZnO 계열의 금속산화물 바리스터의 단락 방지용 소자 적용에 따른 제한전압 특성 분석)

  • Jeong, Tae-Hoon;Choi, Sung-Wook;Jeong, Je-Seon;Kim, Jae-Chul
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1531-1532
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    • 2006
  • Recently, the natural environment changes drastically, and the frequency of occurrence for lightning has gradually been increased. Such lightning delivers high volume of energy along the power line and communication line to the equipment in use. The high volume of energy arising from the lightning surge develops in fast velocity to destroy the facilities in power source and many other facilities in operation in sequential destruction with vast energy. In this thesis, the analysis on the change of clamping voltage characteristics by the contact resistance and lead inductance by using several case studies through the application of element for preventing the short circuit of Metal Oxide Varistor for ZnO.

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Design of the Open-Loop Combined Meandered-Line 1-Layer Radiator for Diversity Antennas with Size-Reduction and Improved Isolation (다이버시티 안테나의 소형화와 격리도 향상을 위한 미앤더 선로와 개방형 루프가 결합된 방사구조의 설계)

  • Mok, Se-Gyoon;Kahng, Sung-Tek;Kim, Yong-Jin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.1
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    • pp.110-116
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    • 2012
  • This paper proposes a new diversity antenna which is the base of MIMO, tunable and reconfigurable antennas. The antenna has a small size and high inter-antenna isolation resulting from the compact radiating element comprising a meandered line and an open-loop combined in one limited uniplanar space and a modified T-shaped decoupling structure, respectively. In a WiMAX band, the radiating element and the entire antenna are $0.092{\lambda}$ and $0.2216{\lambda}$ in size, which shows effective size-reduction and the gain and efficiency of the proposed antenna attached to the ground of a handheld device are 3.7dBi and 56% acceptable to the industrial standard.

Optical design of soft X-ray region monochromator (Soft X-ray 영역 단색화 장치의 광학적 설계에 관한 연구)

  • 성면창;최원국;황정남;정광호;김영식
    • Korean Journal of Optics and Photonics
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    • v.3 no.2
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    • pp.86-91
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    • 1992
  • We describe the design of a soft X-ray grating monochromator for synchrotron radiation in the photon energy range 300~1200eV. We investigate the optimum condition in optical parameters of CEM (cylindrical element monochromator), whose performance is well known by Dragon beam line installed recently at Brookhaven National Laboratory by C. T. Chen, fitting the parameter of PLS (Pohang Light Source) storage ring construction.

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