• Title/Summary/Keyword: 공병

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A Study on Improvement of fatigue Details in Orthotropic Steel Deck Bridge with Bulkhead Plate (벌크헤드 플레이트가 부착된 강바닥판교의 피로상세 개선 연구)

  • 공병승
    • Journal of Ocean Engineering and Technology
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    • v.18 no.1
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    • pp.22-27
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    • 2004
  • An orthotropic steel deck system is widely adapted form for a long-span bridge. It has many advantages, such as the big reduction of dead weight, the simplicity for erection, and the reduction of the construction period. However, an orthotropic steel deck system requires a lot of welding work, which may result in defects and deformation of connection. Therefore, the research for the general behavior and fatigue strength of the several details in orthotropic steel deck bridge is necessary. The fatigue failure with distortion results from secondary stress by out-of-plane deformation; these kinds of cracks are very difficult to measure, and can not be precisely calculated through finite element analysis. This stress concentration phenomenon generates the fatigue failure around the lower scallop of the transverse rib. This paper presents improved details of the intersection between the longitudinal rib and the transverse rib of an orthotropic steel deck bridge by the third dimensional hit size test, and the finite element method, which can minimize local stress through parametric study.

Human Behavior Recognition based on Gaze Direction In Office Environment (실내 환경에서 시선 방향을 고려한 사람 행동 인식)

  • Kong, Byung-Yong;Jung, Do-Joon;Kim, Hang-Joon
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.119-120
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    • 2007
  • 본 논문에서는 실내의 고정된 단일 칼라 카메라에서 획득된 비디오 스트림으로부터 사람의 행동을 인식하기 위한 시스템을 제안한다. 제안된 시스템은 사람의 시공간적 상태 변화와 사람의 시선 방향을 이용하여 규칙기반으로 행동을 인식한다. 사람의 의미 있는 상태변화를 이벤트로, 이벤트의 시퀀스 즉, 사람의 행동을 시나리오로 정의하였다. 따라서 입력비디오 스트림에서 사람의 상태변화로 이벤트를 검출하고, 검출된 이벤트의 시퀀스로 사람의 행동을 인식한다. 사람의 시선은 얼굴과 머리 영역의 색정보를 이용한 시선 방향 추정 방법으로 찾아지며, 사람의 상태 변화는 사람의 위치와 키 등을 이용하여 검출된다. 본 시스템은 실내 환경에서 획득한 비디오에서 실험하였으며, 실험결과 시선 방향에 의해 서로 다른 행동을 구분하여 인식할 수 있었다.

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The Error Rate Performance of digital Radio Signals in Diversity Reception (다이버시티 수신시의 제반 디지탈 신호의 오율특성)

  • 오창헌;공병옥;조성준
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.6
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    • pp.489-497
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    • 1991
  • The error rate pquations of digital radio signals transmitted throught the Nakagami's m-distribution fading channel have been both for nondiversity reception and for diversity reception cases in the environmment of Gaussin noise. Using the derived equation. erro rate performance has been evaluated and represented in figures as a function of carrier to noise ratio, fading figure, and the power correlation coefficient between two diversity branches. By comparing the diversity reception case with nondiversity reception case. We could measure the amount of error rate performance improvenment of digital radiosignals in fanding enviroment.

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가동보의 홍수재해 절감효과에 관한 연구

  • Kim, Phil-Shik;Kim, Sun-Joo;Shim, Jae-Hoon;Park, Hyun-Jun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.808-812
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    • 2010
  • 본 연구에서는 경상남도 마산시의 광려천을 대상으로 미공병단의 HEC-RAS 모형을 선정하여기 설치된 고정보가 있는 하천(ScenarioI), 가동보가 있는 하천(ScenarioII), 시간이 흘러 토사 퇴적이 이루어진 상태의 고정보(ScenarioIII)가 있는 하천 일 때 3개의 하천 단면을 설계하여 하천흐름에 미치는 영향을 분석하고 가동보로 개량시 홍수재해 절감 효과를 분석하였다. 홍수량에 따른 수위분석 결과 ScenarioI, ScenarioIII에서는 수위가 상승하여 여유고 기준을 초과하는 부분이 나타나며, 가동보를 도복했을 경우인 ScenarioII에서는 여유고 기준을 초과하는 부분 없어 가동보의 도복 효과로 홍수시 고정보보다 홍수재해 절감 효과가 있는 것으로 나타났다.

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A Study on Pylon Cable Anchor System in Cable-Stayed Railway Bridge (철도용 사장교의 주탑 케이블 정착부에 관한 연구)

  • Han, Sung-Gwan;Gong, Byung-Seung
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.565-580
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    • 2006
  • Set in constant increase and period current of lively technical development of railroad use and construction of cable stayed bridge railway bridge, one of bridge form of most suitable that think side police officer and the material enemy of bridge that use long rail, is increasing laying stress on the foreign countries. Main tower fixing department of this cable stayed bridge is consisted of main tower flange that support bearing plate, bay ring plate bearing plate, support end rib and diaphragm etc, as stress transmission mechanic that tensility of cable socket into normal force of main tower, and is used this time. These structural elements is very complex the structure and direction of load delivered from socket specially calbe particularly be different, and need FEM analysis that use Thick Shell element for suitable arrangement of mutual stress flowing grasping and absence that follow hereupon because all of the each support plate angle that suport this differ.

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A Study on the Health Monitoring System of Cable Bridge under Construction (특수교량의 시공 중 계측관리 시스템에 관한 연구)

  • Park, Ji-Hwan;Kong, Byung-Seung
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.336-340
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    • 2006
  • The cases of using new methods of big blocks are largely increasing on Recent large-scale bridge structures. So the accurate data of responses of bridges following environmental causes are required to be quickly recorded in order to predict. For this reason described above, the research on measuring system should be conducted for more knowledge of the details on application and stability of new methods. In this study, the new health monitoring system that can monitor the real behavior and damages of the bridge during all processes of construction is presented by analyzing cases of domestic and overseas bridge health monitoring system, and applied methods of following bridges.

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Fatigue Strength Evaluation of T-Peel Adhesive Joing for Light Weight Material (경량 재료의 T형 접합이음의 피로강도 평가)

  • Lee, K.Y.;Kong, B.S.;Choi, H.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.166-173
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    • 1998
  • The evaluation of joint fatigue strength of light weight materials for an electrical vehicle body has been performed through T-peel joint tests with the design parameters such as joint style, adherend type, adherend thickness, adhesive thickness, and various adhesives. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the zero stress ratio. It was observed that the fatigue strength of the joint increases with the increase of the adherend thickness. With the increase of the adhesive thickness, however, the fatigue strength of the joint increases insignificantly. An aluminum-FRP adherend combination shows much higher fatigue strength than an aluminum-aluminum adherend combination. The results of fatigue tests were found to be consistent with those of static tests.

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Design of Speed Controller for Induction Motor With Inertia Variation. (관성 변동을 갖는 유도전동기 속도 제어기 설계)

  • Shin Eun-Chul;Kong Byung-Gu;Kim Jong-Sun;Yoo Ji-Yoon;Park Tae-Sik;Lee Jun-ho
    • Proceedings of the KIPE Conference
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    • 2001.07a
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    • pp.417-421
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    • 2001
  • In this paper, a novel design method of variable motor inetia in Induction motor drive system is proposed. The inertia of a load and a motor are estimated by using RLS (Recursive Least Square) algorithm. The speed controller is designed by Kharitonove theory of motor. The effectiveness of the proposed scheme is verified with simulation and experiments results.

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Design of Speed Controller for Induction Motor With Inertia Variation (관성 변동을 갖는 유도전동기 속도 제어기 설계)

  • 신은철;김종선;공병구;유지윤;박내식;이준호
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.5
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    • pp.446-452
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    • 2001
  • In this paper, a novel design method of variable motor inertia in Induction motor drive system is proposed. The inertia of a load and a motor are estimated by using RLS (Recursive Least Square) algorithm. The speed controller is designed by Kharitonov theory of motor. The effectiveness of the proposed scheme is verified with simulation and experiment results.

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Large-area Synthesis of Well-aligned, Thin Multi-walled Carbon Nanotubes at Low Temperature (수직 정렬된 저직경 다중벽 탄소나노튜브의 저온 대면적 합성)

  • Kim, Young-Rae;Jang, In-Goo;Cho, Jung-Keun;Hwang, Ho-Soo;Kong, Byung-Yun;Lee, Nae-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.418-419
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    • 2007
  • 플라즈마 열화학기상 증착법으로 Fe-Ni-Co 3원계 측매합금을 이용하여 $442^{\circ}C$의 저온에서 다중벽 탄소나노튜브를 합성하였다. 수소의 유량이 일정할 때 아세틸렌의 유량이 감소함에 따라 성장속도가 증가하였다. 합성된 탄소나노튜브는 약 8.4 nm의 직경과 $5.5\;{\mu}m$의 길이를 보였으며, 기판에 대해 수직으로 성장되었다. 4인치 웨이퍼 위에서도 전면적에서 균일한 성장을 보였다.

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