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검색결과 710건 처리시간 0.03초

Running safety of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city

  • Zhang, Yunfei;Li, Jun;Chen, Zhaowei;Xu, Xiangyang
    • Structural Engineering and Mechanics
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    • 제76권2호
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    • pp.207-222
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    • 2020
  • Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train subjected to fluctuating crosswind. To ensure the safe operation in metro lines in mountain cities, running safety of the metro train over the high-pier bridge under crosswind is analyzed in this paper. Firstly, the dynamic model of the wind-train-bridge (WTB) system is built, in which the speed-up effect of crosswind is fully considered. On the basis of time domain analysis, the basic characteristics of the WTB system with high-pier are analyzed. Afterwards, the dynamic responses varies with train speed and wind speed are calculated, and the safety zone of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city is determined. The results indicate that, fluctuating crosswind triggers drastic vibration to the metro train and high-pier bridges, which in turn causes running instability of the train. For this reason, the corresponding safety zone for metro train running on the high-pier is proposed, and the metro traffic on the high-pier bridge should be closed as the mean wind speed of standard height reaches 9 m/s (15.6 m/s for the train).

Fluid-structure interaction analysis of deformation of sail of 30-foot yacht

  • Bak, Sera;Yoo, Jaehoon;Song, Chang Yong
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제5권2호
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    • pp.263-276
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    • 2013
  • Most yacht sails are made of thin fabric, and they have a cambered shape to generate lift force; however, their shape can be easily deformed by wind pressure. Deformation of the sail shape changes the flow characteristics over the sail, which in turn further deforms the sail shape. Therefore, fluid-structure interaction (FSI) analysis is applied for the precise evaluation or optimization of the sail design. In this study, fluid flow analyses are performed for the main sail of a 30-foot yacht, and the results are applied to loading conditions for structural analyses. By applying the supporting forces from the rig, such as the mast and boom-end outhaul, as boundary conditions for structural analysis, the deformed sail shape is identified. Both the flow analyses and the structural analyses are iteratively carried out for the deformed sail shape. A comparison of the flow characteristics and surface pressures over the deformed sail shape with those over the initial shape shows that a considerable difference exists between the two and that FSI analysis is suitable for application to sail design.

머리 위치에 따른 사위도의 변화 (Head Posture-Induced Phoria Deviation)

  • 하은미;손정식;문병연;유동식
    • 한국안광학회지
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    • 제15권2호
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    • pp.155-160
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    • 2010
  • 목적: 머리 위치에 따른 사위도 변화를 평가하고, 외안근의 불균형과 관련하여 좌 우안의 프리즘 량을 달리할 필요성을 확인하고자 하였다. 방법: 20~30세 남자 44명(88안), 여자 16명(32안)을 대상으로 차폐검사, 자각적 굴절검사, 사위검사 및 융합여력검사를 실시하였다. 머리기울임 검사, 얼굴돌림 검사에 따른 사위 변화량을 비교분석하기 위해 본 그래페를 이용하여 측정하였다. 결과: 머리기울임과 얼굴돌림에 따른 사위도 변화는 Morgan 표준의 수평사위 비정상군에서 유의한 차이를 보였고(p<0.05), 특히 근거리 Sheard 기준으로 수평사위 처방이 필요한 그룹에서 근거리 수평사위 변화량이 크게 나타났다(p<0.05). 수평사위 비정상군의 원거리 Sheard 기준으로 처방이 필요한 그룹과 필요하지 않은 그룹 모두 머리 위치에 따라 사위도 변화는 근거리일 경우 보다는 적었다. 결론: 수평사위 비정상군의 Sheard 기준 처방이 필요한 그룹에서 근거리 머리기울임, 얼굴돌림의 수평사위 변화량이 크게 나타났다. 따라서 근거리 사위에서 프리즘 처방을 해야 할 때 좌 우 외안근의 불균형의 존재를 확인하여 좌 우안에 프리즘량을 달리 처방할 필요성이 있는 것으로 본다.

Trigger point를 이용(利用)한 구안와사 환자(患者) 10례(例)에 대한 임상적(臨床的) 고찰(考察) (Clinical investigation studies on 10 cases of patient with Bell' palsy using Trigger point treatment)

  • 정영돈;이준구;김영일;박태균;신영일;황재연;이현;이병렬
    • 혜화의학회지
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    • 제10권2호
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    • pp.155-165
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    • 2002
  • From July 1th 2001 to October 31th 2001, the Clinical investigation studies were carried out 10 cases of patient with Bell' palsy using Trigger point treatment group, who had been treated in Han-seung Oriental Medical Clinic. The results were like below: 1. The distribution of sex : Male were 4cases. female were 6case and the female to male ratio was 1.5 : 1. 2. The distribution of contributing factor : Unknown reason was most predominant 4 cases, and then were revealed to labor too hard. mental stress(3 cases), trauma common cold(1 case) in turn. 3. The distribution of perid to fall ill : Under a week was the most number 6cases, and then were revealed a week under two weeks(3 cases), over two weeks(1 case) in turn. 4. About period of treatment : The Trigger Point treatment group is shorter than the Acupuncture treatment group. 5. The distribution of grade on admission in descending order : Gr I was the most number and then GrII, GrIII in turn. 6. The distribution of clinical symptoms on admission : Mastoid pain was the most number 9 cases and then lacrimal gland disorder 8 cases, dysgeusia 4cases, hyperacusis 2 cases, the others 2 cases in turn. 7. About effect of treatment : The Trigger point treatment group is more excellent than the Acupuncture treatment group. 8. The more patient age is young, the more effect of treatment was excellent, had nothing to do with both groups. 9. The more perid to fall ill is short, the more effect of treatment was excellent. had nothing to do with both groups. 10. About period of improved frontal belly : The Trigger point treatment group is more excellent than the Acupuncture treatment group.

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신호교차로 대향좌회전 상충심각도 구분에 관한 연구 (A Study of Opposing Left-Turn Conflict Severity at Signalized Intersections)

  • 김응철;박지형;오주택;노정현
    • 한국도로학회논문집
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    • 제9권4호
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    • pp.83-92
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    • 2007
  • 도로교통안전관리공단(2005)이 발표한 자료에 의하면 우리나라의 2004년 총 교통사고 건수는 220,755건이며, 사망자는 6,563명으로 조사되었으며, 이중 교차로에서의 사고가 1/4 이상을 차지하고 있는 것으로 보고하고 있다. 교차로 교통사고는 통행 특성상 단일로에 비하여 많은 상충점을 가지고 있어 사고의 잠재성이 높은 것이 사실이다. 교통상충기법은 다양한 측면에서 기존의 교통사고 자료를 활용한 분석방법보다 그 활용도가 높으며, 보다 많은 필요성이 제기되고 있지만, 기존의 교통상충기법은 신호교차로에서 발생하는 다양한 상충유형에 대해 상충발생의 심각도를 고려하지 못하는 단점을 가지고 있었다. 이에 본 연구에서는 신호위반시 발생하는 대향좌회전 상충의 유형에 대하여 상충심각도를 고려한 새로운 상충판단기준을 정립하였으며, 이를 인천광역시의 교통사고발생이 빈번한 교차로를 선정하여 상충수와 심각도를 분석하였다. 취득한 대상 교차로의 영상을 3시간 동안 분석한 결과, 총 41건의 대향좌회전상충이 발생하였으며, 각각의 심각도는 '상'이 3건, '중'이 10건 그리고 '하'가 28건 발생한 것으로 확인되었다. 신호교차로에서 발생하는 상충유형의 심각도 연구가 필요한 근거는 보다 교차로의 안전도를 평가하는데 있어 보다 정밀하게 접근하고자 함이며, 상충의 심각도가 고려되지 못한 기존의 상충발생의 건수만을 이용한 연구로는 상충연구가 가지는 의의가 제한적이기 때문이다. 또한, 본 연구의 결과는 대향좌회전상충유형을 비롯한 신호교차로에서 발생하는 다양한 상충유형의 심각도 판단기준을 정립하는데 중요한 기초자료가 될 것으로 판단된다.

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일본의 해양기본법 제정과 우리의 대응방안 연구 -한중일 해양행정체계 비교를 중심으로- (A Study on the Analysis of Japan's Basic Ocean Law and Policy of Korea -The Case of Korea, Japan and China on the Administrative System for Ocean-)

  • 박성욱;양희철
    • Ocean and Polar Research
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    • 제30권1호
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    • pp.119-128
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    • 2008
  • Japan's new Basic Ocean Law took effect in 20 July 2007. This law contains that 1) calls for the consolidation of eight government offices that previously worked separately on maritime issues; 2) establishes a basic plan for maritime matters, and; 3) creates a comprehensive maritime policy headquarters, run by the Prime Minister. The result is a structure for the integrated promotion of maritime policy. The Minister of Land, Infrastructure and Transport has been appointed to the newly established position of maritime minister. Japan has been in conflict with Korea and China over EEZ and territory, which has caused the country to turn to ocean. If Japan puts more emphasis on sea, it will be on a collision course with neighboring countries such as Korea, China, Russia, and Taiwan. Japan has been at odds with these countries; with Korea over Dokdo islets, with China over the Senkaku Islands and the East China Sea, where gas fields lie, with Taiwan over fishery rights in the East China Sea, with Russia over the Kuril Islands. Korea's position about the establishment of Japan's new Basic Ocean Law is followed: 1) expression of Korea's position in maritime resourcces of east china sea, 2) understand of strategy for maritime resources development and maritime delimitation in China and Japan, 3) a caution for extention of EEZ and maritime activities, 4)effective and comprehensive policy establishment, and strength in R&D, 5) construction of active and responsive system for maritime issues in neighbor country.

설계 초기 단계에서 전력/클록 네트워크를 고려한 라우팅 밀집도 예측 방법론 (Power/Clock Network-Aware Routing Congestion Estimation Methodology at Early Design Stage)

  • 안병규;정정화
    • 전기전자학회논문지
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    • 제16권1호
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    • pp.45-50
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    • 2012
  • 본 논문은 설계 흐름의 초기 단계에서 SoC의 라우팅 밀집도를 빠르고 정확하게 예측하는 방법론을 제안한다. 라우팅 과정에서 발생하는 과도한 밀집 현상은 라우팅 실패를 야기하고, 물리 설계를 처음부터 다시하게 되는 불필요한 시간을 소모하게 한다. 설계 초기단계에서 라우팅 밀집도를 정확하게 예측하는 것은 성공적인 물리 설계를 이끌어 내며, 전체 설계 시간에 소모되는 비용을 최소화시킨다. 제안된 방법은 블록 수준 플로어플랜 단계에서 블록 간/블록 내부 인터커넥트, 가상으로 합성된 파워/클록 네트워크를 사용해서 정교한 라우팅 밀집도를 예측한다.

TMS32OC31 DSP칩에 의해 제어되는 연료전지용 전력변환장치의 설계 (Design of fuel cell power conversion system controlled by TMS32OC31 DSP Chip)

  • 문상필;권순걸;서기영;김영문
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.351-354
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    • 2006
  • Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system Therefor, this paper, consists of an isolated DC -DC converter to boost the fuel cell voltage 380[$V_{DC}$] and a PWM inverter with LC filter to convent the DC voltage to single phase 220[$V_{AC}$]. Expressly, a tapped inductor filter with freewheeling diode is newly implemented in the output filter of the proposed high frequency isolated ZVZCS PWM DC-DC converter to suppress circulating current under the wide output voltage regulation range, thus to eliminate the switching and transformer turn-on/off over-short voltage or transient phenomena Besides the efficiency of 93-97[%]is obtained over the wide output voltage regulation ranges and load variations.

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Increased Expression of Cyclin D3 are Involved in Hepatocellular Carcinoma

  • Kim, Gi-Jin;Sun, Woong;Won, Nam-Hee;Park, Sun-Hwa
    • Molecular & Cellular Toxicology
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    • 제4권2호
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    • pp.93-99
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    • 2008
  • Human cyclin D3 gene (CCND3) located on 6p21.1 is important for the regulation of the G1-S phase transition of the cell cycle by modulating the activity of the cyclin-dependent kinases Cdk4 and Cdk6. Because little is known about the effect of cyclin D3 in various human cancers, we evaluated the intricate relationship between expression of cyclin D3 and the process of HCC development using immunohis tochemistry and TUNEL assay on 43 paraffin embedded tissues. Cyclin D3 immunoreactivity was more frequently observed in the tumors with high histologic grade and the tumors with metastasis, and more frequently expressed in HCCs with cirrhotic background and gain of 6p21.1 when compared with those with non-neoplastic tissue. Apoptotic cells were more common in tumor with cirrhotic background, amplification of 6p21.1 and expression of cyclin D3 when compared with HCCs with lower level of cyclin D3 expression. Also, we observed that some of the cyclin D3 positive cell and apoptotic cell were co-localized. From these results, it is suggested that over-expression of cyclin D3 may contribute to more rapid cell turn-over in the background of HCC, and balance between proliferation and apoptosis is a role in the progression of HCC with cirrhotic background.

플라이백 컨버터방법에 의한 태양광발전설비의 납축전지 스위칭모드 전환형 펄스충전기 개발 (Development of the Switching Mode Conversion Type Pulse Charger for the Lead Battery of Solar Cell Generator Equipment by Fly-Back Converter Method)

  • 신춘식;안영주;김동완
    • 전기학회논문지P
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    • 제58권1호
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    • pp.20-26
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    • 2009
  • In this paper, the switching mode conversion type pulse charger by fly-back converter method for lead battery of the solar cell generator equipment is proposed. And we propose the control circuit and design method of insulated switching mode convert type pulse charger by fly-back convert method in the lead battery. The proposed system can minimize the current consumption by digital pulse. Also the proposed system can generate the constant 10[KHz] frequency, transmit the signal with main control system in the power control system. And it supervises the state of lead battery using one chip micro processor. The proposed the switching mode conversion type pulse charger by the fly-back converter method can charge fast and stabilize lead battery with nominal value 12[V], 20[AH]. Also we propose the design procedure of the power control circuit for turn ratio of fly-back inductor and determining method of values such as the charging current, bulk current, partial current, over current value and fixed charging voltage. The experiment results for the voltage and current wave for partial, bulk, over and fixed charging period show the good charging effect and performance. And the PCB and internal coupling diagram of the switching mode conversion type pulse charger by fly-back converter method is presented.