• Title/Summary/Keyword: MegaStudy

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

  • Kim, Hwi-Dong;Baek, Nam-Choon
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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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
    • International conference on construction engineering and project management
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    • 2011.02a
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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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    • v.35 no.4
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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
    • International conference on construction engineering and project management
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    • 2009.05a
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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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Mega Sport Event and Social Capital: A Host Community Perspective Comparison in Korea and the US through Social Conflict Theory (메가스포츠이벤트와 사회적 자본의 역할: 갈등이론을 중심으로 한 한국과 미국의 이벤트 유치지역사회의 관점 비교에 대한 연구)

  • Park, Seong-Hee;Cottingham, Michael;Seo, Won-Jae
    • The Journal of Industrial Distribution & Business
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    • v.9 no.9
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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.

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

  • Choi, Changhyun;Han, Daegun;Kim, Jungwook;Jung, Jaewon;Kim, Duckhwan;Kim, Hung Soo
    • Journal of Wetlands Research
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    • v.18 no.1
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    • pp.76-83
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    • 2016
  • In recent, the series of extreme storm events were occurred by those continuous typhoons and the severe flood damages due to the loss of life and the destruction of property were involved. In this study, we call Mega flood for the Extreme flood occurred by these successive storm events and so we can have a hypothetical Mega flood by assuming that a extreme event can be successively occurred with a certain time interval. Inter Event Time Definition (IETD) method was used to determine the time interval between continuous events in order to simulate Mega flood. Therefore, the continuous extreme rainfall events are determined with IETD then Mega flood is simulated by the consecutive events : (1) consecutive occurrence of two historical extreme events, (2) consecutive occurrence of two design events obtained by the frequency analysis based on the historical data. We have shown that Mega floods by continuous extreme rainfall events were increased by 6-17% when we compared to typical flood by a single event. We can expect that flood damage caused by Mega flood leads to much greater than damage driven by a single rainfall event. The second increase in the flood caused by heavy rain is not much compared to the first flood caused by heavy rain. But Continuous heavy rain brings the two times of flood damage. Therefore, flood damage caused by the virtual Mega flood of is judged to be very large. Here we used the hypothetical rainfall events which can occur Mega floods and this could be used for preparing for unexpected flood disaster by simulating Mega floods defined in this study.

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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    • v.59 no.2
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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.

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

  • 윤은상;이화기
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.50
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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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Composition of Worship Space in Megachurches (대형교회 예배공간 구성)

  • Ryu, Bo-Young;Lee, Kang-Hoon
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2005.10a
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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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Development of Structural Analysis and Pre-post Program for Mega Frame System (초대형 골조시스템 전용 전후처리 및 해석프로그램의 개발)

  • Kim Hyun-Su;Lee Dong-Guen
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.19 no.3 s.73
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    • pp.283-293
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    • 2006
  • Recently, various types of structural systems for skyscrapers are studied as the height and size of the building structures rapidly increase due to social and economical needs. The mega frame system among them, which is the structural system developed recently, is known as a suitable structural system for skyscrapers because this structural system has sufficient stiffness against the lateral forces by combination of mega members which consist of many columns and girders. Since the mega frame structure has significant numbers of elements and nodes, it takes tremendous times and computer memories to analyze and design the structures. Therefore, the exclusive structural analysis program for mega frame system is developed to reduce the efforts and time required for the analysis and design of mega frame structure. To this end, an efficient modelling technique using the characteristics of mega frame structures and an efficient analytical model, which uses a few DOFs selected by the user using the matrix condensation method, are developed in this study. Static and dynamic analyses are conducted using an example structure. The effectiveness and accuracy of the developed program we verified by the comparison between the results of the proposed method and the conventional method.