• 제목/요약/키워드: MegaStudy

검색결과 471건 처리시간 0.026초

입구 유량변화에 따른 메가 집열기 지관의 유량분포특성에 대한 수치해석 (Numerical Study on the Flow Distribution Characteristics with Varying Inlet Flow-Rate in Mega Collector Risers)

  • 김휘동;백남춘
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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    • pp.150-154
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    • 2009
  • Flow distribution characteristics with varying inlet flow-rate in mega collector risers have been investigated, using commercial code FLUENT. The heat transfer in mega collector was not considered in this numerical study. Through the simulation, the following results were found. First, flow distribution characteristics in mega collector risers show the similar tendency in all cases. Secondly, with increased inlet flow-rate, flow distribution uniformity was getting worse.

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DEVELOPMENT OF A WEB-BASED COST AND DURATION MANAGEMENT SYSTEM FOR MEGA-PROJECTS

  • Chang-Taek Hyun;Run-Zhi Jin;Myoung-Jin Son;Seung-Yoon Shin
    • 국제학술발표논문집
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    • The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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    • pp.510-515
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    • 2011
  • Urban renewal projects, in the form of mega-projects, are being actively implemented both nationally and internationally to revitalize inactive cities. These programs, however, are difficult to manage efficiently due to their need for a large budget over a long period of time and due to conflicts with stockholders. Moreover, existing cost and duration management systems are structured with emphasis on the design and construction stage of unit projects, thus limiting their application to long-term mega-projects that are integrated with various facilities. To solve these problems, this study developed a web-based system that can collectively manage the cost and duration of mega-projects at a program level. The unit modules included in the system--CBS organization, construction cost and duration prediction, and total cost and duration prediction--can support decision-making at the early stage of the program. Furthermore, the modules, which include contract management, execution management, change management, and program progress management, support the program operations for its successful accomplishment. The web-based cost and duration management system developed in this study is expected to be used as a valuable tool that supports the successful accomplishment of mega-projects through their efficient management throughout their life cycle.

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Alleviation of Ultraviolet B-Induced Photoaging by 7-MEGATM 500 in Hairless Mouse Skin

  • Park, Kyo-Hyun;Kim, JiYeon;Jung, Suryun;Sung, Kyung-hwa;Son, Yeon-Kyoung;Bae, Jung Min;Kim, Bae-Hwan
    • Toxicological Research
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    • 제35권4호
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    • pp.353-359
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    • 2019
  • The purpose of this study was to investigate the effect of $7-MEGA^{TM}$ 500 on the improvement of skin aging in an UVB-induced photo-aging model of hairless mice. The dorsal skin of hairless mice was exposed to UVB three times a week for 12 weeks to induce skin wrinkle. After inducing the wrinkle, $7-MEGA^{TM}$ 500 was orally administered once a day for 4 weeks. Skin thickness, skin barrier function, and wrinkle indicators were improved by treatment with $7-MEGA^{TM}$ 500. Both gene and protein expression levels of MMP-3 and c-Jun in skin were significantly decreased by $7-MEGA^{TM}$ 500. Therefore, the intake of $7-MEGA^{TM}$ 500 is thought to have a positive effect on the improvement of skin aging, although further studies are needed.

ESTABLISHMENT OF DECISION MAKING FRAMEWORK FOR SUPPORTING COOPERATION AMONG STAKEHOLDERS IN MEGA PROJECT

  • Jee Hee Lee;June Seong Yi;Seung Woo Shin;Kyung Rog Park
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1288-1293
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    • 2009
  • Performing 'Mega Project' in which various stakeholders are involved is difficult to control due to the respective conflicting objectives. Urban regeneration which is being challenged issue in various ways can be defined as the mega project. Since the mega project like urban regeneration a long-continued project and includes a lot of participants whose benefits conflict, cooperation among stakeholders is essential. Moreover, as the project goes, diverse decision making situations which require collaboration happen, and if proper decision making cannot be given at that time, the whole project would have critical effects. Also, since each activity concerns numerous stakeholders, prompt decision making is difficult in the mega project. Therefore, the objective of this study is to support stakeholder's cooperative decision making in order for conducting successful project. For the purpose of the paper, the concept of cooperation in mega project is redefined and a cooperative decision making framework is suggested. Also, the term of governance, which means cooperative mechanism based on the mutual trust, information sharing and partnership, is applied to the newly defined cooperation. The suggested cooperative decision making framework contains the structure of stakeholders in urban regeneration project which enables participants to understand the relationship among bodies and checklists for supporting decision making appropriately. The application of the framework proposed in this research is expected to contribute subjects' suitable decision making by providing proper information in a timely manner.

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메가스포츠이벤트와 사회적 자본의 역할: 갈등이론을 중심으로 한 한국과 미국의 이벤트 유치지역사회의 관점 비교에 대한 연구 (Mega Sport Event and Social Capital: A Host Community Perspective Comparison in Korea and the US through Social Conflict Theory)

  • 박성희;마이클 코팅험;서원재
    • 산경연구논집
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    • 제9권9호
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    • pp.63-74
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    • 2018
  • Purpose - The current study is to compare the cognition of stakeholders on hosting a mega sports event between Korea and the United States. In particular, to understand their cognition and perceptual conflict towards hosting a mega sports event, the study employed conflict theory. Furthermore, the study reviewed the role of social capital in the process of managing the mega sports events. Research Design, Data, and Methodology - Of homogeneous sampling, purposeful sampling method and criterion-based selection approach were used to collect interview data from key stakeholders who have been involved in hosting a mega sports events in Korea and the United States. In-depth interview transcripts were reviewed multiple tiems after transcription to extract concepts and meanings that were pertinenet to the experience involving hosting a mega sports event. Further member checks was conducted to increase the credibility of the results. Results - Results can be summarized as followed: First, stakeholders of Korea have a strong desire for positive economic effects of a mega sports event, compared to those in the United States who are more concerned in enhancing the public interests and concerns. Second, in Korea, various socio-political issues emerged at the same time and conflicts among multiple stakeholders have aggravated the situations to coordinate the issues. This was because legal system supporting socio-trust has not been established. On the other hand, major stakeholders of the United States consisted of community members who have socio-trust and networks. Thereby these social resources have been found playing a key role in building social capital that assists the stakeholders to coordinate the current issues and to solve them. Conclusions - The current study analyzed the cognition and perceptual conflict of stakehoders in a mega sports event. Social capital has beend found as a key catalyst to increase a network and cooperation among stakeholders. In order to enhance social capital in managing a mega sports event hosted in Korea, legal systems that establish networks and relationships among the related stakeholders need to be developed. Furthermore, the systematic guideline needs to be developed, organizing the sub-committees according to the types of stakeholders and the categorized common needs.

연속적인 극한호우사상의 발생을 가정한 거대홍수모의 (Mega Flood Simulation Assuming Successive Extreme Rainfall Events)

  • 최창현;한대건;김정욱;정재원;김덕환;김형수
    • 한국습지학회지
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    • 제18권1호
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    • pp.76-83
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    • 2016
  • 최근 연속적인 태풍에 의한 일련의 극한 호우 사상으로 홍수가 발생하였고, 이로 인해 인명과 막대한 재산피해가 발생하였다. 본 연구에서는 연속 호우 사상으로 인해 발생한 극한홍수를 거대홍수라고 정의하고, 일정 시간 간격으로 극한 호우 사상이 연속적으로 발생 될 수 있음을 가정하여 가상의 거대홍수 시나리오를 구성하였다. 최소 무강우 시간 결정(Inter Event Time Definition, IETD)방법을 사용하여 연속적인 강우의 시간 간격을 결정하였으며, IETD에 의해 산정된 시간 간격 안에서 호우 사상을 연속적으로 발생시켜 평창강 유역을 대상으로 거대홍수를 모의하였다. 즉, (1) 기록된 극한 호우 사상의 연속적인 발생 (2) 기왕 자료를 기반으로 빈도해석에 의해 산정된 설계 호우 사상의 연속적인 발생을 가정하여 거대홍수를 모의하였다. 연속 호우 사상으로 인한 거대홍수는 단일 호우 사상으로 인한 일반 홍수에 비해 6~17%의 홍수량이 증가하는 것으로 나타났다. 앞의 호우 사상으로 인한 홍수량에 비해 뒤에 오는 호우로 인한 홍수량의 증가는 많지 않지만, 연속적인 호우는 두 번의 홍수피해를 가져오므로 가상의 거대홍수로 인한 홍수 피해는 매우 클 것으로 판단된다. 따라서 본 연구와 같이 가상의 강우 시나리오를 통해 예상하지 못한 연속적인 홍수 재해와 같은 비상 상황에 대비할 방안을 마련할 필요가 있을 것으로 사료된다.

Effect of pre-stressed cable on pre-stressed mega-braced steel frame

  • Tang, Baijian;Zhang, Fuxing;Wang, Yi;Wang, Fei
    • Structural Engineering and Mechanics
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    • 제59권2호
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    • pp.327-341
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    • 2016
  • This study addresses the effect of pre-stressed cables on a pre-stressed mega-braced steel frame through employing static analysis and pushover analysis. The performances of a pre-stressed mega-braced steel frame and a pure steel frame without mega-braces are compared in terms of base shear, ductility, and failure mode. The influence of the cable parameters is also analyzed. Numerical results show that cable braces can effectively improve the lateral stiffness of a pure frame. However, it reduces structural ductility and degenerates structural pre-failure lateral stiffness greatly. Furthermore, it is found that 20% fluctuation in the cable pretension has little effect on structural ultimate bearing capacity and lateral stiffness. As comparison, 20% fluctuation in the cable diameter has much greater impact.

대형 건설사업에서의 사업관리정보시스템 구축에 관한 연구 (A Study on the Development of Project Management Information System for Mega Project)

  • 윤은상;이화기
    • 산업경영시스템학회지
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    • 제22권50호
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    • pp.243-255
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    • 1999
  • A mega project such as an international airport construction generally consists of a number of sub-projects. Successful completion of this mega project requires project management information system(PMIS) because control and link of a number of component sub-projects is inevitable. Therefore, the role of PMIS should be more emphasized as the project is processed and managed by fast track concept where the design and construction work is performed concurrently. This study investigates and analyzes the present PMIS developed for the construction project of Inchon International airport. Based on this study, we can suggest the direction of PMIS for a mega project management and how to improve this kind of management information system.

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대형교회 예배공간 구성 (Composition of Worship Space in Megachurches)

  • 유보영;이강훈
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2005년도 추계학술발표대회 논문집
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    • pp.85-89
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    • 2005
  • Within a short period of time of evangelical activities in Korea, the Korean Christianity has been explosively grown since 1884. Now Korea became one of the top countries exporting many missionaries to other countries. We call the 1970s and after as the time of diversity in Korean churches and those buildings. In this period, Korean churches have grown larger and bigger, so called mega-churches. Including Yoido Full Gospel Church, Seoul with 10,000 seats, there are 22 mega-churches in Korea out of the world top 50 mega-churches. Having the necessity of knowing the composition of worship space of mega- or super-mega-churches, we analyzed and classified the information of mega-churches which were built after 1970s. We collected resources through blueprints, visitations of buildings, and interviews by phone, For this study and research, we selected total 66 churches. Based upon the existing theories, we categorized the plane of worship space, its axis, the arrangement of attendant seats, the location of the choir, and the pattern of a cross section of buildings. We also brought the conclusion of specific characteristics given through the analysis according to the time period, the style, and the denomination of megachurches.

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초대형 골조시스템 전용 전후처리 및 해석프로그램의 개발 (Development of Structural Analysis and Pre-post Program for Mega Frame System)

  • 김현수;이동근
    • 한국전산구조공학회논문집
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    • 제19권3호
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    • pp.283-293
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    • 2006
  • 근래에 들어서 사회적 및 경제적인 요구에 의하여 건축구조물이 점차 고층화 및 대형화됨에 따라서 다양한 형식의 구조시스템이 연구 및 개발되고 있다. 비교적 최근에 개발된 초대형 골조시스템은 초대형부재의 조합으로 횡방향 강성을 충분히 발휘함으로써 초고층건물에 적합한 구조시스템으로 인식되고 있다. 그러나 이러한 초대형 골조시스템을 적용한 건물의 거동을 예측하기 위해서는 매우 많은 수의 절점과 요소로 이루어진 유한요소 모델을 해석해야 하므로 상당한 양의 해석시간과 엔지니어의 노력이 필요하게 된다. 따라서 본 연구에서는 초대형 골조시스템 전용 해석프로그램을 개발하여 초대형 골조구조물의 해석과 설계에 소요되는 시간과 노력을 줄이고자 한다. 이를 위하여 초대형 골조구조물의 특징을 활용한 효율적인 모형화기법과 행렬응축기법을 사용하여 해석에 사용되는 자유도수를 최소화도록 만든 해석모델이 개발되었다. 예제구조물의 해석을 수행하여 본 연구에서 개발된 프로그램을 사용한 결과와 일반적인 해석방법에 의한 결과와 비교함으로써 개발된 프로그램의 효율성과 정확성을 검증하였다.