• Title/Summary/Keyword: connecting

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COSMOLOGICAL LINEAR PERTURBATION THEORY (우주구조 선형건드림 이론)

  • Hwang, Jai-Chan
    • Publications of The Korean Astronomical Society
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    • v.26 no.2
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    • pp.55-70
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    • 2011

  • Cosmological linear perturbation theory has fundamental importance in securing the current cosmological paradigm by connecting theories with observations. Here we present an explanation of the method used in relativistic cosmological perturbation theory and show the derivation of basic perturbation equations.

  • https://doi.org/10.5303/PKAS.2011.26.2.055 인용 PDF KSCI

Problems and Improvements of Transportation on TSR (TSR 운송의 주요문제점 및 개선방향)

  • 최은영;이찬우;정흥채
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.343-348
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    • 2002

  • We are going to build a direct railway line between Europe and Asia by connecting North-South line. It can reduce a transportation distance by above 10,000km. But problems of TSR which is most important line have been exposed such as backward facilities and operations. In this paper we find out problems of TSR in detail and show those improvements.

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Measured Return Loss and Predicted Interference Level of PCB Integrated Filtering Antenna at Millimeter-Wave

  • Lee Jae-Wook;Kim Bong-Soo;Song Myung-Sun
    • Journal of electromagnetic engineering and science
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    • v.5 no.3
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    • pp.140-145
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    • 2005

  • In this paper, an experimental investigation for return loss and a software-based prediction for interference level of single-packaged filtering antenna composed of dielectric waveguide filter and PCB(Printed Circuit Board) slot antenna in transceiver module have been carried out with several different feeding structures in millimeter-wave regime. The implementation and embedding method of the existing air-filled waveguide filters working at millimeter-wave frequency on general PCB substrate have been described. In a view of the implementation of each components, the dielectric waveguide embedded in PCB and LTCC(Low Temparature Co-fired Ceramic) substrates has employed the via fences as a replacement with side walls and common ground plane to prevent energy leakage. The characteristics of several prototypes of filtering antenna embedded in PCB substrate are considered by comparing the wideband and transmission characteristics as a function of bent angle of transmission line connecting two components. In addition, as an essential to the packaging of transceiver module working at millimeter-wave, miniaturization technology maintaining the performances of independent components and the important problems caused by integrating and connecting the different components in different layers are described in this paper.

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Transition Zone Behavioral Characteristics with Increase the Speed of High Speed railroad (고속철도 열차 증속에 따른 접속부 거동특성 분석)

  • Park, Hyo-Sung;Kim, Nak-Seok;Kang, Yun-Suk
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1583-1593
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    • 2011

  • As we see the continuation of the increase in the speed of the High Speed railroad worldwide, there is a concern for a possible problem in the connecting transition zone in the railway infrastructure. Honam High Speed railroad's transition zone in the hub for the rotation structures and other supporting structures such as approach slab, sub slab, approach block, etc. Due to its increase in speed of the design speed, and its important role on the driving stability and credibility of the bearing ground performance, we must seek and fine a prevention plan for a cause of differential settlement, as well as the cause of the derailment. In this dissertation, domestic, as well as international design manuals and the applicability of the control standards are studied. Also through the study target, Honam High Speed railroad zone 4-1, we evaluated the connecting componant of the Yeon-Jeong bridge through the eigenvalue and weight transfer of the train when operated at 300km/h, 350km/h, 400km/h, 450km/h, and were able to achieve detailed assessment by checking track behaviors, looking at various components such as the rotation acceleration according to the inversion of the distance length, displace length, displacement and stress distribution. Through these studied, possibility of operating at 400km/h was evaluated based on the condition of the current design basis.

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