• 제목/요약/키워드: 박형기

검색결과 495건 처리시간 0.029초

등가선형 지반스프링모델을 사용한 교량의 지진응답해석 (Seismic Response Analysis of Bridges Using Equivalent Linear Soil/Foundation Spring Model)

  • 박형기
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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    • pp.372-380
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    • 2000
  • Seismic forces for member design of bridges may be determined by modifying elastic member forces induced by design earthquakes using appropriate response modification factors according to national design code of bridges. Modeling of soil/foundation system is one of the critical parameter in the process of elastic seismic analysis of bridge system which greatly affects on the analysis results. In this paper, a simplified modelling procedure of soil/foundation system which gives practically reasonable results is presented and its applicability has been validated through example bridge. Based on the results, it has been shown that the procedure is acceptable in modelling soil/foundation system for practical seismic analysis of bridges.

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구조물의 지진취약도분석을 위한 비탄성에너지흡수능력의 평가 기법에 관한 비교 연구 (Comparative Study on Evaluation of Inelastic Energy Absorption Capacity for Seismic Fragility Analysis of Structures)

  • 조양희;조성국;박형기
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2002년도 춘계 학술발표회 논문집
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    • pp.135-142
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    • 2002
  • This paper introduces the technologies related to seismic resistance assessment of nuclear power plant structures by seismic fragility analysis(SFA). The inelastic energy absorption factor is considered in SFA to represent the effects due to the nonlinear behavior of structures and has a significant effect on the seismic fragility that is a probability of failure of structures by earthquake. Several practical methods to evaluate the inelastic energy absorption capacity of structures are investigated. The capacities determined by those methods are compared with each other. And an improved method that uses the inelastic demand capacity diagram is presented. Conclusively, some comments on each method for practical application are made.

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전기기구의 운전에 의하여 발생되는 자계의 측정 (Measurement of Magnetic Field Generated by the Operations of Electric Appliance)

  • 이복희;길경석;박형기
    • 대한전기학회논문지
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    • 제43권6호
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    • pp.1001-1009
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    • 1994
  • The present paper deals with a new developed sensor for measuring the time-varying magnetic fields and describes the experimental results of trasient magnetic field that takes place during the operations of electric appliance. The operation principle of the self-integrating magnetic field sensor by using coaxial cable is analyzed and a calibration investigation is carried out. The frequency bandwidth of the magnetic field measurement system is from 40 Hz to about 300 kHz. The magnetic field induced by the starting and/or operation of electric appliance mainly includes the odd harmonics such as the third, the fifth and the seventh harmonics. The magnetic field intensity caused during the operation of ultrasonic washer is inversely proportional to distance, this correspodns to induction component. As a result, it was known that the odd harmonics of magnetic field in the desing of electromagnetic shield employed for protecting electronic circuit and control devices have to be considered.

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차량검지시스템(VDS) 메타데이터의 표준화에 관한 연구 (A study on the Standardization of metadata in Vehicle Detection System)

  • 박형기
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2007년도 춘계학술발표대회
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    • pp.568-571
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    • 2007
  • 본 연구에서는 차량검지시스템을 이용하여 메타데이터의 검지시스템의 하드웨어와 소프트웨어가 도로에 적합한 시스템이 되도록 실험을 통하여 이를 검증하고, 표준화를 위해 제안하였다. 첫째, 교통정보를 메타데이터하고자 할 때 그 구축범위가 너무 광범위한 점을 보완하여 시내 교통정보의 범위를 줄이고자 적용범위로 VDS(차량검지시스템 : Vehicle Detection System)의 메타데이터 구성요소에 대한 표준을 마련하였다. 둘째, 본 표준에서는 차량의 속도, 단위 시간당 차량의 통과수 및 점유시간 등을 조사할 수 있는 VDS의 메타데이터 구성요소를 추출하고 데이터 요소에 대한 정의 및 기술형식을 정의하였다. 셋째, VDS의 메타데이터 표준지정은 교통정보의 데이터 요소 및 형식을 동일하게 사용하도록 함으로써 상이한 개발업체에 의해 개발된 시스템의 교통정보를 일관성 있게 표현할 수 있다. 넷째, 본 표준은 VDS 메타데이터의 데이터 요소명을 표준화하기 위해서 Data Dictionary를 구축하여 실제 데이터 요소에서 data dictionary에서 정의된 약어들의 조합으로 표시하여 데이터 모델링시 유용하게 쓰일 수 있도록 하였다.

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특정지반에 적용할 설계응답스펙트럼에 대한 고찰 (A Study on the Applicatin of Design Response Spectrum to a Specific Soil Profile)

  • 박형기
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2001년도 춘계학술대회 논문집
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    • pp.91-99
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    • 2001
  • This paper is for a reasonable selection of design response spectra for the seismic design of specific types of soil-structure interaction systems, e.g., underground structure within flexible soil profiles of structures on the shallow soil layers on the stiff bed rock. the existing backup data used for determining the design response spectra of the Code have been investigated and evaluated. For this purpose, various types of free field analyses have been performed using one-dimensional wave propagation theory considering the nonlinear properties of the soil profile. As a result, a reasonable approach of determining input response spectra for specific soil profiles has been proposed to be compatible to the design response spectra of the Code.

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전기기기의 조작시 발생되는 자계성분 평가에 관한 연구 (Evaluation of Magnetic Field Components Produced by Electric Machine Operations)

  • 이복희;박형기;전덕규;백용현;정승수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1993년도 춘계학술대회 논문집
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    • pp.68-71
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    • 1993
  • 본 연구에서는 자기적분형 자계센서의 감쇠시간특성과 주파수 응답특성에 대해 조사하였으며, 감쇠시간은 4.4[ms]이고, 측정가능한 주파수대역은 40[Hz]에서 1[kHz]이다. 또한, 적절하게 저항과 콘덴서의 용량을 조절하여 전기기기에 대한 측정도 가능함을 확인하였다.

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웨이블릿 변환을 이용한 구조물의 동특성 분석 (Identification of Structural Dynamic Characteristics Using Wavelet Transform)

  • 박종열;김동규;박형기
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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    • pp.391-398
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    • 2001
  • This paper presents the application method of a wavelet theory for identification of the structural dynamic properties of a bridge, which is based on the ambient vibration signal caused by the traffic loadings. The method utilizes the time-scale decomposition of the ambient vibration signal , i . e. the continuous wavelet transform using the Morlet wavelet is used to decompose the ambient vibration signal into the time-scale domain. The applicability of the proposed approach is verified through the reduced scale bridge and automobile system in the laboratory. The results of verification shows that the use of the Morlet wavelet to identify the structural dynamic properties is reasonable and practicable.

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