• 제목/요약/키워드: Majority Problem

검색결과 361건 처리시간 0.023초

스트립 배열된 다수 부이에 의한 파력에너지 추출 (Wave Power Extraction by Strip Array of Multiple Buoys)

  • 조일형
    • 한국해양공학회지
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    • 제28권5호
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    • pp.474-483
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    • 2014
  • The majority of existing WECs (wave energy converters) are designed to achieve maximum power at a resonance condition. In the case of a single WEC, its size must be large enough for tuning, and it has high efficiency only within a limited frequency band. Recently, wave power extraction by deploying many small buoys in a compact array has been studied under the assumption that the buoy's size and separation distance are much smaller than the water depth, wave length, and size of the array. A boundary value problem involving the macro-scale boundary condition on the mean surface covered by an infinite strip of buoys is solved using the eigenfunction expansion method. The energy extraction efficiency (${\varepsilon}=1-R^2_f-T^2_r$), where $R_f$ and $T_r$ are the reflection and transmission coefficients for a strip array of buoys, is assessed for various combinations of packing ratio, strip width, and PTO damping coefficient.

Should accidental eccentricity be eliminated from Eurocode 8?

  • Anagnostopoulos, S.A.;Kyrkos, M.T.;Papalymperi, A.;Plevri, E.
    • Earthquakes and Structures
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    • 제8권2호
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    • pp.463-484
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    • 2015
  • Modern codes for earthquake resistant building design require consideration of the so-called accidental design eccentricity, to account for torsional response caused by several factors not explicitly considered in design. This provision requires that the mass centres in the building floor be moved a certain percentage of the building's dimension (usually 5%) along both the x and y axes and in both positive and negative directions. If one considers also the spatial combinations of the two component motion in a dynamic analysis of the building, the number of required analyses and combinations increases substantially, causing a corresponding work load increase for practicing structural engineers. Another shortcoming of this code provision is that its introduction has been based primarily on elastic results from investigations of oversimplified, hence questionable, one story building models. This problem is addressed in the present paper using four groups of eccentric braced steel buildings, designed in accordance with Eurocodes 3 (steel) and 8 (earthquake design), with and without accidental eccentricities considered. The results indicate that although accidental design eccentricities can lead to somewhat reduced inelastic response demands, the benefit is not significant from a practical point of view. This leads to suggestions that accidental design eccentricities should probably be abolished or perhaps replaced by a simpler and more effective design provision, at least for torsionally stiff buildings that constitute the vast majority of buildings encountered in practice.

한의사들의 천연물 신약 처방의사에 관한 연구 (A Study on Prescription Intention of Botanical Drug in Korean Medicine Doctors)

  • 권용찬;빈성오;구진숙;서부일
    • 대한본초학회지
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    • 제30권5호
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    • pp.7-13
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    • 2015
  • Objectives : The purpose of this study was to examine the prescription intention of Korean medicine doctors on botanical drug.Methods : The subjects in this study were 340 Korean medicine doctors in Korean medical institutions, on whom a survey was conducted from July 1 to August 31, 2014.Results : The factors that affected the prescription decision making of the Korean medicine doctors were drug superiority, level of Interest, Recognition, marketing of sales associates of pharmaceutical companies and satisfaction with information provided by those companies. When the internal consistency of the variables was measured, that was above 0.8.Conclusions : Accordingly, well-planned education and promotion efforts are required to encourage Korean medicine doctors to put more prescription intention in botanical drug. This study had some limitations : First, the subjects were selected in a manner to allow for the convenience of this researcher, and the findings might not be generalizable. Second, there was a problem with the time for the study in that there were quite fierce disputes on botanical drug at that time. Third, the majority of the subjects run their own hospitals, and the number of them was small. So it's not possible for them to represent every Korean medicine doctor.

여교사의 시부모관 (The View of Home Economics Teachers on Parents-in-Law)

  • 이정우
    • 대한가정학회지
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    • 제11권4호
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    • pp.388-398
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    • 1973
  • The increase of female employees tends to change the traditional division of the roles of members in the family, and as a result it changes the idea of family relation and the extent of how housewives with job feel happy toward their marriage. Therefore, it may be very significant to study what attitude woman job holders as housewives have toward their family, especially parents-in-law. In this paper the writer has sampled as an exemplary group woman teachers who teach home economics in high schools in Seoul, and investigated what opinion they have toward the problem of living together under the same roof with their parents-in-laws and otherwise of financing them in an older age. This analysis is based upon 130 questionnaires collected as proper data out of 138. The conclusion made from the analysis is as follows : (1) as regards the living together under the same roof if necessary in the future, one-fifth of the group approves in affirmative terms ; (2) but when parents-in-law become older, about half of the teachers wish to live with them in the same home and except the indefinite few, one-third of them taken the negative position ; (3) finally, the great majority (84%) regard as their duty the financial support in any case when parents-in-law become older, and only five per cent answer in negative. This analysis leads to the further conclusion that the idea of family relations cherished by high school teachers of home economics is not yet far off the traditional relationship with the intention of gradual improvement, but on the other it still sticks to the traditional line without too much impairing it.

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전동차 제동기의 유압화에 관한 연구 (A Study on Application of Hydraulic Brake System)

  • 이한민;김길동;오세찬;박성환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.169-171
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    • 2008
  • The brake systems of the rolling stocks are generally consisted of electrical and mechanical brake systems. Because of its inherent structure of the each brake system, the electrical brake system is mainly used at the high speed range while the mechanical brake system is used at the relatively lower speed range. It is desirable for the rolling stocks to apply the entire electrical brake system. However, since the brake force from electric brake system is not enough to stop the rolling stock within the legal stop distance. Therefore, the mechanical brake system is indispensable to rolling stocks. In general, the vast majority of the world trains are equipped with mechanical braking systems which use compressed air as the force to push block on to wheels or pads on to discs. These mechanical systems are known as air brake or pneumatic brakes. For the air brake system, basically huge scale air compressor is equipped and the long pipe line is complexively connected. Since mass of these air brake components, it is difficult to be a light weight equipment and the long pipe line raise the maintenance problem. In order to overcome these problems of air brake system, the hydraulic brake system is proposed in this research. The hydraulic brake system makes the whole weight of brake equipment be light and large braking force can be applied. Therefore, in this research, the validity and advantages of applying the hydraulic brake system are reviewed.

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수학 올림피아드 참가자에 대한 환경요인의 영향에 관한 연구

  • 조석희;이정호;이진숙
    • 영재교육연구
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    • 제7권2호
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    • pp.19-45
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    • 1997
  • Twenty-three of International Math Olympians raised in Korea were served as the subjects to answer the following questions: (1) What family and school factors contribute to the development of the math talent of the Olympians\ulcorner (2) What impacts have the Olympiad program on the mathematically talented students\ulcorner By means of questionnaire survey and in-depth interview, the related data were collected. The questionnaires were developed by James Campbell for cross-cultural studies. The major findings were as follows: (1) the olympians were mostly 1st-born child and were "discovered" in an early age; (2) most olympians ranked highly in the class; (3) the SES of the Olympians' family were varied, though the majority were high; (4) the Olympians' family support and learning environment were reported strong and positive; (5) the Olympiad experiences were, in general, positive to the subjects, especially in learning attitude toward math and science, self-esteem and in autonomous learning and creative problem solving; (6) there were almost none special program designed for the Olympians during their school years; (7) the degree of computer literacy were varied according to the subject's personal interest and the accessibility to the computer; (8) most Olympians had not yet showed special achievement other than math as there were still students; (9) the Olympians were individuals with unique characteristics.teristics.

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일반측량 성과도를 활용한 수치지도의 실시간 수정갱신 체계화 연구 (A study on the realtime renewal and update of digital map using general survey)

  • 이상길;권재현;양효진;전재한
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2006년도 춘계학술발표회 논문집
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    • pp.393-398
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    • 2006
  • Currently, 54 kinds of digital maps are provided by National Geographic Information Clearinghouse and the majority of those maps are based on aerial photographs or satellite image. The digital maps which symbolize and simplifies the topography and objects from ortho-photos does not reflect the objects 'shapes and facilities' changes. Especially, underground structures and complex building shapes are not correctly identifies by ortho-photos. Furthermore, the 1/1,000 and 1/500-1/2,500 maps for urban area produced by some local government or public organizations have detailed information with high precision, it is not easy to update the information due to the frequent changes of structures in the city. Although some efforts to solve this problem such as conducting field survey and shorten the survey period were tried, it is not the fundamental solution due to the high cost. Therefore, in this study, a realtime renewal and update of digital map using general survey are suggested. By assigning absolute coordinates to the general survey products and matching with digital maps, it is possible to update the digital map economically and rapidly. In addition, it is suggested that the construction of DB for general survey and sharing among survey companies to solve the duplicated survey.

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중국(中國)의 의료과오책임(醫療過誤責任) (The Medical Malpratice Liability of Chinese)

  • 박동매
    • 의료법학
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    • 제7권2호
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    • pp.113-136
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    • 2006
  • In recent years, as well as the other countries, medical dispute cases increase continuously in China. one of the reason that medical cases increase rapidly like this is after reformation and opening people's sense of independence, law and right come to be high, but a theoretical study about medical malpractice liability is insufficient and there is deficiency at legislation from 1986 civil law general rule is carried out in Chinese. but it is difficulty to deal with those more and more complicated medical dispute only according to the law above. so in 2001 The Chinese Supreme Court established the judicial construction about civil litigation evidence which regulated the shift of the burden of proof of medical malpractice and the relation of cause and effect from the plaintiffs to the defendants. in 2002 the State Council made out Incident of Malpractice Processing Rule. but many scholar pointed out the problem in it. on the other side, according to Chinese Contract Law parties could choose contractual or tort liability to prosecute. but because of the judicial construction above majority of people asked tort liability. of course there are some cases asking contractual liability. then this paper aim at analysis of the Chinese medical malpractice liability, especially of the problems about the subject of responsibility, burden of proof and scope of responsibility.

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자궁경관 및 난관에 병합된 복합 자궁외 임신 1예 (A Case of Combined Ectopic Gestation with Cervical and Tubal Components)

  • 홍승화;권혜은;김성훈;채희동;김정훈;강병문
    • Clinical and Experimental Reproductive Medicine
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    • 제30권3호
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    • pp.249-254
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    • 2003
  • Ectopic pregnancy is a common medical problem that is difficult to diagnose and potentially may lead to significant mortality or morbidity. The incidence of ectopic pregnancy is definitely increasing ue to the rise in pelvic inflammatory disease (PID), pelvic surgery, intrauterine device (IUD), and assisted reproductive technologies, such as in vitro fertilization and embryo transfer (IVF-ET). Combined ectopic gestations are much rare and their true incidence is unknown. Multiple ectopic gestations may occur in a variety of locations. The majority involve one or both fallopian tubes. We report a case of combined tubal and cervical pregnancies, and discuss their management.

Non-FIFO 메모리 구조를 사용한 입력버퍼형 스위치에서 개선된 DBP 윈도우 기법 (An Improved DBP Window Policy in the Input Buffer Switch Using Non-FIFO Memory Structure)

  • 김훈;박성헌;박광채
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1998년도 학술발표대회 논문집 제17권 2호
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    • pp.223-226
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    • 1998
  • In the Input Buffer Switch using the intial stage FIFO memory structure, It has pointed the Throughput limitation to the percent of 58.6 due to HOL(Head of Line) blocking in the DBP(Dedicated Buffer with Pointer) method, During that time, To overcome these problems, The prior papers have proposed the complicated Arbitration algorithms and Non-FIFO memory structures. and These showed the improved Throughput. But, Now, To design high speed ATM Switch which need to the tens of Giga bit/s or the tens of Tera bit/s. It has more difficulty in proceeding the priority of majority and the complicated Cell Scheduling, because of the problem in operating the control speed of the ratio of N to scanning each port and scheduling the Cell. In this paper, To overcome these problems, We could show more the improved performance than the existing DBP Window policy to design high speed ATM Switch.

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