• 제목/요약/키워드: Chang-Ki(張機)

검색결과 419건 처리시간 0.029초

SAM 알고리즘을 이용한 하천제방 붕괴예측에 관한 연구 (A Study of a Levee Failure Forecasting using SAM Algorithm)

  • 유병선;박용대;이규식;장기태
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 춘계 학술발표회
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    • pp.649-658
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    • 2009
  • The Aim of this development is the safety management network of embankment facilities using forecasting analysis algorism. Using this algorithm it is possible to predict a failure of embankment facilities in advance. therefore, it is necessary for making plans of a safety countermove. In this development we have researched the analysis method which could operate effectively the embankment facilities using real-time monitoring data from a remote sensing system and the safety managerial program using the algorithm from the analysis method developed.

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영구자석 계자형 동기발전기의 고조파 저감을 위한 자기회로 최적설계 (Shape Optimization for the EMF Harmonics Reduction of PM type Synchronous Generators)

  • 이재건;임양수;김영균;장규홍;홍정표;장기찬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.57-59
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    • 2001
  • This paper presents the shape optimization to minimize the BEMF(Back Electro-Motive Force) harmonics of PM type synchronous generators. RSM(Response Surface Methodology) is used to find the optimal solution. We used the 2D-Finite Element Method to obtain the observed data of the BEMF and SQP(Sequential Quadratic Problem method) is used to solve the constrained nonlinear optimization problem.

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분포형 광섬유센서를 활용한 지표이동 측정에 관한 연구 (A Study of Slope Movements Using Fibre Optic Distributed Deformation Sensor)

  • 장기태
    • 지구물리
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    • 제8권2호
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    • pp.75-80
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    • 2005
  • Optical fibre sensors have shown a potential to serve real time health monitoring of Slope and structure. They can be easily embedded or attached to the structures and are not affected by the electro-magnetic field. Furthermore, they have the flexibility of the sensor size and very highly sensitive. In this study, we conducted several laboratory on slope and field tests using a novel optical sensor based on Brillouin scattering and PVC pipe. One of the advantages of this technique is that the bare fibre itself acts as sensing element without any special fibre processing or preparation. Test results have shown that BOTDR can be a great solution for sensor systems of Slope.

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구리(Ⅱ)-아민류 착물에 의한 l-ascorbic acid의 산화반응속도와 메카니즘 (Rates and Mechanism of the Oxidation of l-Ascorbic Acid with Cu(Ⅱ)-Polyamine Complexes)

  • 김선덕;박정은;장기호;신한철;김창수
    • 대한화학회지
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    • 제39권1호
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    • pp.29-34
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    • 1995
  • 구리(II)-아민류 착물에 의한 l-ascorbic acid의 산화반응속도를 pH 4.6에서 Onishi 방법으로 측정하였다. 이 반응의 메커니즘은 l-ascorbic acid가 구리(II) 착물에 배위된 다음 속도결정단계에서, 전자이동이 일어나는 내부권 메커니즘에 따라 반응이 진행됨을 알았다.

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CdS 분말 및 박막의 광학적 특성 (The Optical Characteristics of CdS Thin Films and Powders)

  • 장기석
    • 한국결정학회지
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    • 제19권1호
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    • pp.25-30
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    • 2008
  • In order to characterize the optical properties of CdS thin films and CdS powders, the following experiments were performed: CdS wurtzite thin films were made using 99.99% CdS (Aldrich) powder and the $AlO_x$ membranes in $7{\times}10^{-6}$ torr(here, the average vacuum coating speed is $1{\AA}/sec$.). The surface states of CdS nano-particles with dimensions of 3.87 nm were studied through the fluorescence spectroscopy. From the resulting spectra exhibited, we can see a sharp fluorescence at 451 nm arising from the excitons on the CdS thin films, compared with the 448nm peak of the CdS powders.

SRM의 설계변수에 따른 고정자의 고유진동수 해석 (Natural Frequency Analysis of Stator in Switched Reluctance Motor According to Design Parameters)

  • 하경호;안호진;강경호;홍정표;김규탁;장기찬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.708-710
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    • 2000
  • The interaction of electromagnetic forces and mechanical structure of switched reluctance motors(SRM) is the major cause of the noise and vibration. The stator part in SRM produces the most vibrations. Therefore, it is necessary to know the natural frequencies of the stator. In this paper, the variation of natural frequencies according to the design parameters is investigated to avoid the resonance. The natural frequency of the tested motor is founded by the frequency response function obtained by a experimental modal analysis.

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전자기 및 구조 유한요소법을 이용한 브러시레스 전동기의 응력 해석 (Stress Analysis of Brushless Motor by Using Structural and Electromagnetic Finite Element Method)

  • 하경호;강경호;홍정표;장기찬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.617-619
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    • 2000
  • This paper deals with the mechanical stress analysis caused by the electromagnetic radial force and the design considering the stress. The link in an Interior Permanent Magnet Brushless Motor(IPM) have influence on the mechanical and magnetic performance. Therefore, it is necessary to determine the appropriate link thickness. The optimal geometry link is designed by using the coupled with structural and electromagnetic Finite Element Method.

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