• 제목/요약/키워드: Power system disturbances

검색결과 342건 처리시간 0.022초

Seismic pounding between adjacent buildings considering soil-structure interaction

  • Raheem, Shehata E Abdel;Alazrak, Tarek M.A.;AbdelShafy, Aly G.A.;Ahmed, Mohamed M.;Gamal, Yasser A.S.
    • Earthquakes and Structures
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    • 제20권1호
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    • pp.55-70
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    • 2021
  • In urban cities, buildings were built in the neighborhood, these buildings influence each other through structure-soilstructure interaction (SSSI) and seismic pounding due to limited separation distance in-between. Generally, the effects of the interaction between soil and structure are disregarded during seismic design and analysis of superstructure. However, the system of soil-base adversely changes structural behavior and response demands. Thus, the vibration characteristics plus the seismic response of a building are not able to be independent of those in adjacent buildings. The interaction between structure, soil, and structure investigates the action of the attendance of adjacent buildings to the others by the interaction effect of the sub-soil under dynamic disturbances. The main purpose of this research is to analyze the effects of SSSI and seismic pounding on the behavior of adjacent buildings. The response of a single structure or two adjacent structures with shallow raft base lying on soft soil are studied. Three dimensions finite element models are developed to investigate the effects of pounding; gap distance; conditions of soil; stories number; a mass of adjacent building and ground excitation frequency on the seismic responses and vibration characteristics of the structures. The variation in the story displacement, story shear, and story moment responses demands are studied to evaluate the presence effect of the adjacent buildings. Numerical results acquired using conditions of soil models are compared with the condition of fixed support and adjacent building models to a single building model. The peak responses of story displacement, story moment, and story shear are studied.

주요우울장애 환자에서의 자율신경심장기능 - Heart Rate Variability 검사를 사용하여 - (Autonomic Neurocardiac Function in Patients with Major Depressive Disorder - Using a Heart Rate Variability Test Battery -)

  • 박영수;이강준;김현;정영조
    • 수면정신생리
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    • 제11권2호
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    • pp.100-105
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    • 2004
  • 목 적:본 연구의 목적은 주요우울장애환자를 대상으로 Heart Rate Variability(HRV) 검사를 이용하여 비침습적으로 자율신경계의 기능, 심혈관조절체계 및 항상성을 측정하여 정상대조군과 비교해보고 생리학적, 임상적 의미를 고찰해보는 것이다. 방 법:DSM-Ⅳ의 진단기준에 의하여 주요우울장애로 진단받은 환자 30명과 정상대조군 30명을 대상으로 하였다. 검사는 SA-2000E 기기를 사용하여 HRV parameter를 측정한 후 시(time) 영역과 주파수(frequency)영역별로 분석하였다. 결 과:Heart rate(HR)는 환자군에서 유의하게 증가된 소견을 나타내었으며 the standard deviation of the NN interval(SDNN), the root square of successive differences(RMSSD)도 환자군에서 유의하게 낮은 소견을 보였다. Total power(TP) band, very low frequency(VLF:$0.003{\sim}0.04\;Hz$) band, low frequency(LF:$0.04{\sim}0.15\;Hz$) band, high frequency(HF:$0.15{\sim}0.4\;Hz$) band는 환자군에서 유의하게 낮은 수치를 보였고, LF/HF의 비는 유의한 차이를 나타내지 않았다. 결 론:우울증 환자는 심박수의 증가와 HRV의 감소를 보였으며, 교감 신경과 미주 신경의 불균형이 높은 심혈관계 사망률과 부분적으로 연관이 있는 것 같다. 우울증 환자들은 심장에서 자율신경기능의 이상을 나타내며 이렇게 교감/부교감 신경활성 조절능력이 저하되어 균형이 깨짐으로써 높은 심혈관계 사망률을 보인다고 할 수 있다.

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