• 제목/요약/키워드: extreme point

검색결과 271건 처리시간 0.026초

점선원 감마선장에서 유효선량의 성별차 및 개연선량당량과의 차이 (Effective Doses in the Radial Gamma Radiation Field near a Point Source: Gender Difference and Deviation from the Personal Dose Equivalent)

  • 장재권;이재기
    • Journal of Radiation Protection and Research
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    • 제22권4호
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    • pp.299-307
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    • 1997
  • 점선원 주위에 형성되는 방사상의 감마선장에서 개인선량당량 $H_p$, 유효선량 E, 성별 유효선량 $E^m$$E^f$를 MIRD형 남녀 모의 피폭체를 이용하여 평가하였다. 선원은 신체의 전방 각각 15, 40 및 100 cm 거리의 여러 높이에 있는 것으로 하였고 방사성 핵종으로는 시범적으로 $^{137}Cs$$^{131}I$을 선정하였다. 성별 유효선량에서는 일부 예외적인 경우-예를 들면 선원이 생식선 앞에 위치할 때-를 제외하고는 대체로 여성의 경우가 크게 나타났으나, 남녀 평균값과의 차이는 크지않아 방사상 감마선장에서 성별 유효선량환산인자를 사용할 필요성은 없었다. 선량계를 가슴에서 하복부까지의 몸통 전방에 착용할 경우에는 $H_p$/E의 비가 약$1{\sim}3$의 범위에 있었고 극단적인 경우는 0.34에서 6.5까지 큰 편차를 보였다. 그러나 일반적인 방사선원 취급방법과 선량계 착용위치(흉곽 전방)를 가정하고, 선량계가 넓고 평행한 방사선장에서 유효선량에 대해 교정된다면 평행하지는 않지만 넓은 빔인 방사상 감마선장에 대해서는 용인할 수 있는 오차의 범위에서 유효선량 평가치를 제공할 수 있을 것으로 나타났다.

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신화론적(神話論的) 관점(觀點)에서 해석(解釋)한 안도 타다오의 건축적(建築的) 특성(特性)에 관한 연구(硏究) -철학가(哲學家) 한스 불루멘버그의 신화론적(神話論的) 관점(觀點)을 중심(中心)으로- (A Study on the Mythological Interpretation of the House Designed by Tadao Ando -Focused on the mythological thinking of Hans Blumenberg-)

  • 변태호
    • 건축역사연구
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    • 제13권2호
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    • pp.39-55
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    • 2004
  • In terms of the way we perceive the world, the history of human beings might be said to be a history of two incompatible forces -'science' and 'myth.' Until today, both indispensable aspects have made human existence possible and characterized human culture. Nonetheless, an essential definition of myth has never been clearly explained. What is the general philosophical thought about myth? Current well known interpretations are so called Enlightenment and Romanticism of myth, which both has same criticism that they has not generally considered myth in terms of its technical function or specified contents. One who overcomes the limit of two current extreme beliefs on myth and also who concerned more with the ultimate origin of myth and its relation to the structure of poetry than the source of its vital accomplishments is philosopher Hans Blumenberg. For him myth is an artificial means and an answers to overcome the 'absolutism of reality.' On this point, the research concerns basically two issues. One is to investigate the functional and structural characters of myth through philosopher Hans Blumenberg's anthropological reflections. The other is to analyze architect Tadao Ando's works and thinking. The intention of the paper is not only to explore the relationship between philosophical theory of Blumenberg and Ando's architectural works, but also to suggest a new critical understanding on architecture from mythological point of view. I also expect that this research will suggests a concrete theoretical idea for constructing and construing artistic form and cultural space.

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The Study on Selection of human Model for Controllability Evaluation According to Working Postures

  • Kim, Do-Hoon;Park, Sung-Joon;Lim, Young-Jae;Jung, Eui-S.
    • 대한인간공학회지
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    • 제31권3호
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    • pp.437-444
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    • 2012
  • The purpose of this study was to suggest appropriate human model for ergonomic evaluation considering working postures on 3D space. Background: Traditionally extreme design rules have been widely utilized at the stage of designing products. Body size of 5th percentile and 95th percentile in stature has been generally selected for controllability and clearance evaluation, respectively. However, these rules had limitations in reflecting working posture in ergonomic evaluation. Method: In order to define working posture on 3D space, not only sagittal plane but also lateral plane was considered. Kinematic linkage body model was utilized for representation of working posture. By utilizing the anthropometric data of 2,836 South Korean male populations, the point cloud for end points of linkage models was derived. The individuals who were lacking in certain controllability were selected as human models for the evaluation. Result: In case of standing posture it was found that conventional approach is proper for all controllability evaluations. Contrary to standing posture, tall people had less controllability on control location below shoulder point in sitting posture. Conclusion: From the derived proper range on controllability, ergonomic evaluation rule was suggested according to working posture especially in standing and sitting. Application: The results of the study are expected to aid in selection of appropriate human model for ergonomic evaluation and to improve the usability of products and work space.

지상 레이저 스케닝 자료를 활용한 댐체의 변형해석 (Deformation Analysis of Dam Structure using Terrestrial Laser Scanning System)

  • 김영경;손호웅;임은상;임정열;김기영
    • 지구물리
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    • 제9권4호
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    • pp.333-341
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    • 2006
  • 준공 후 상당한 시간이 경과한 댐에 대해서 안정성을 판단하거나 관리하는 방법은 극히 제한적이다. 댐체의 변형 특성을 확인하기 위해서는 침하계와 같이 1 point에 대한 거동만 분석을 실시하였으나, 댐체의 전체적인 변형특성을 파악 할 수 없었다. 따라서 본 연구에서는 지상 레이저 스캐닝을 이용하여 댐체의 전체적인 변형 특성을 분석하였으며, 댐체에 설치된 표면 침하계 결과와 비교하였다. 레이저 스캐닝 자료와 표면 침하계 결과를 분석한 결과 연구대상댐은 댐체의 자중에 의한 변형거동을 보이고 있다고 판단 할 수 있었고, 현시점에서의 댐체는 안정화 단계에 접어들고 있다는 것을 확인할 수 있었다.

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고온용 PV module을 위한 PVB film 광특성 연구 (The analysis on PVB film optical characteristics for PV module generating in high-temperature)

  • 이상훈;김경수;강기환;유권종;안형근;한득영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1320-1321
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    • 2011
  • According to the advance that solar power plants go into the desert, power plants are getting greater capacity. The desert is unspoiled resources and it is well suited to build a solar power plant, because of abundant solar radiation and long sunshine duration. but existing PV modules have several weaknesses and don't generate lower the rated power, because it wasn't designed to produce in extreme environments like a desert climate. The one of the weaknesses of PV modules is that the characteristics of the temperature of the Encapsulants(EVA sheet) are not good in a desert climate, because the EVA sheet is melt at high temperature. In this study, a decrease phenomenon of the transmittance depending on the melting point of the Encapsulant(PV module using EVA sheet : $75^{\circ}C$ PV module using PVB film : $110^{\circ}C$) is suggested, it would be the one of the important factors to achieve rated output of the PV modules in high temperature climate regions.

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태양광모듈의 장기적 신뢰성 실험 (Long-Term Reliable Test of Photovoltaic Modules)

  • 김경수;권오은;강기환;유권종;윤순길
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1405-1405
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    • 2011
  • Sudden earthquake is changing national energy stratagem for future energy resource. In case Germany, current nuke power station will be shut down with several decades. Newly constructed build in Japan must have photovoltaic system as a obligations.. As a long-term sustainable energy one, PV should give confidence to customers up to more than 20 years. Today, IEC 61215 and IEC 61646 standards are representative one for ensuring performance and safety of PV module. But it is still needed to develop more realistic test method. For example, if we think about extreme condition like desert and North Pole, the temperature condition describe in test standards can have little effect on life time expectation of PV module. Installation speed of PV system is very high, but establishing test standards are very complex and not easy. So in this paper, I tried to open the long-term test method for PV module to ensure 25 year's old life time. It is just starting point of PV related long-term test methods. The specific and technical explanation will be shown in the following paper in detail.

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A Strong LP Formulation for the Ring Loading Problem with Integer Demand Splitting

  • Lee, Kyung-Sik;Park, Sung-Soo
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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    • pp.306-310
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    • 2004
  • In this paper, we consider the Ring Loading Problem with integer demand splitting (RLP). The problem is given with a ring network, in which a required traffic requirement between each selected node pair must be routed on it. Each traffic requirement can be routed in both directions on the ring network while splitting each traffic requirement in two directions only by integer is allowed. The problem is to find an optimal routing of each traffic requirement which minimizes the capacity requirement. Here, the capacity requirement is defined as the maximum of traffic loads imposed on each link on the network. We formulate the problem as an integer program. By characterizing every extreme point solution to the LP relaxation of the formulation, we show that the optimal objective value of the LP relaxation is equal to p or p+0.5, where p is a nonnegative integer. We also show that the difference between the optimal objective value of RLP and that of the LP relaxation is at most 1. Therefore, we can verify that the optimal objective value of RLP is p+1 if that of the LP relaxation is p+0.5. On the other hand, we present a strengthened LP with size polynomially bounded by the input size, which provides enough information to determine if the optimal objective value of RLP is p or p+1.

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액체로켓 터보펌프 구동터빈의 구조 강도 및 진동 안전성에 관한 연구 (Investigation on the Strength and Vibration Safety of the Liquid Rocket Turbopump Turbine)

  • 전성민;김진한;이대성
    • 한국항공우주학회지
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    • 제31권8호
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    • pp.77-84
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    • 2003
  • 액체로켓용 터보펌프 터빈 블레이드-디스크의 구조 및 진동 해석이 설계점에서의 구조 강도 및 동특성을 고찰하기 위하여 수행되었다. 터보펌프의 높은 회전 속도로 인하여 구조 해석시 원심력 영향이 주의깊게 고려되었다. 극심한 온도 분포에 따른 열하중 또한 터빈 블레이드-디스크에 작용하는 외부하중으로 고려되었다. MSC/NASTRAN DMAP Alter를 이용한 3차원 유한요소법이 주기 대칭 구조 해석에 적용되었다. 회전 속도에 따른 구조 동특성의 고찰을 위하여 블레이드간 위상차가 고려되었다. 수치해석을 통하여 원심력과 열하중이 터빈 블레이드-디스크에 미치는 영향을 고찰하였다.

공학 분야의 윤리적 문제해결방법: 매트릭스 가이드 (Ethical Problem Solving in Engineering: Matrix Guide)

  • 한경희;허준행;윤일구;이강택;강호정
    • 공학교육연구
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    • 제15권1호
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    • pp.61-71
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    • 2012
  • The core issue of ethical problem solving in engineering is to understand what exactly happened and to define its nature. Problems often arise mostly in morally complex situations. Traditional philosophical theories usually focus on extreme conflicts of interest and suggest moral theory-centered problem solving methods. However, these methods are not only difficult to specifically apply to real situations, but also are likely to fail to deal with actual moral issues in engineering fields. This study aims to develop more desirable ethical problem solving methods, based on STS (Science and Technology Studies) and engineering ethics combined. First, we have examined the engineering ethics with implications of an STS perspective, then have analyzed traditional ethical problem solving methods in a critical point of view. This study will suggest a new ethical problem solving method named Matrix Guide, based upon those analyses. Specifically, this study classifies four stages of problem definition, analysis, solving, and feedback. Here, we focus on how to combine technological and non-technological factors in each stage, when we are facing morally complex situations in engineering sectors.

Multiscale self-coordination of bidimensional empirical mode decomposition in image fusion

  • An, Feng-Ping;Zhou, Xian-Wei;Lin, Da-Chao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권4호
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    • pp.1441-1456
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    • 2015
  • The bidimensional empirical mode decomposition (BEMD) algorithm with high adaptability is more suitable to process multiple image fusion than traditional image fusion. However, the advantages of this algorithm are limited by the end effects problem, multiscale integration problem and number difference of intrinsic mode functions in multiple images decomposition. This study proposes the multiscale self-coordination BEMD algorithm to solve this problem. This algorithm outside extending the feather information with the support vector machine which has a high degree of generalization, then it also overcomes the BEMD end effects problem with conventional mirror extension methods of data processing,. The coordination of the extreme value point of the source image helps solve the problem of multiscale information fusion. Results show that the proposed method is better than the wavelet and NSCT method in retaining the characteristics of the source image information and the details of the mutation information inherited from the source image and in significantly improving the signal-to-noise ratio.