• Title/Summary/Keyword: Large system

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Watertightness Property Evaluation of Rain-Block System (개폐식 대공간 구조물에서 지붕 맞댐부 우수차단 시스템의 수밀성 평가에 관한 연구)

  • Kim, Yun-Ho;Baek, Ki-Youl;Kim, Jong-Su;Lee, Sun-Gyu;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.13-16
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    • 2010
  • This study is an Investigation on the Watertightness Properties of Rain-Block System on the Sliding-Roof Joint of Large-Span Membrane Structures. In this experimental, we test the watertightness performance of joint part of sliding door in roof of large span membrane structure(for pilot project) under environment of rain and wind. A shape of rain water blocking systems of joint part in sliding door verifies the defects and effects of water leakage prevention in precipitation with the wind conditions. For obtaining watertightness of large span membrane structures, it is necessary quality of joints and performance, and quality of membrane material of a retractable roof as well as a closed roof. Also, for obtaining quality in joints, it is essential to make a watertightness guideline for design of large-span membrane.

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Robust Controllers for Large Space Structures Using an SPR Filter and Displacement Feedback (변위ㆍ정보와 SPR 필터를 이용한 대형 우주 구조물의 강인 제어기에 관한 연구)

  • 손영익;심형보;조남훈
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.9
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    • pp.520-525
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    • 2003
  • A robust controller for large space structures(LSS) is studied from passivity point of view. While velocity sensors are commonly used for proportional-derivative (PD) control law to stabilize large space structures, if the structure can be controlled without velocity measurements, it is desirable against the failure of velocity sensors and for the cost reduction of the sensing system. In a recent result a dynamic output feedback control law has been provided using only displacement measurements. This paper presents a passivity-based controller design method and provides an alternative stability analysis tool for the previous displacement feedback robust control law. The closed-loop system can be viewed as a feedback interconnection of a passivated large space structure (LSS) and a strictly positive real (SPR) system.

Enhancement of Turbulent Heat Transfer of the Cooling System in Nuclear Reactor by Large Scale Vortex Generation

  • Chun, Kun-Ho;Park, Jong-Seok;Choi, Young-Don
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.2
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    • pp.77-84
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    • 2001
  • Experimental and computational studies were carried out to investigate the turbulent heat transfer enhancement of the cooling system in nuclear reactor by large scale vortex generation. The large scale vortex motion was generated by rearranging the inclination angels of mixing vanes to the coordinate direction. Axial development of mean and turbulent velocities in the subchannels were measured by the 2-color LDV system. Eddy diffusivity concept based on $\kappa{-}\varepsilon$ model was employed to calculate the turbulent heat and momentum transfers in the subchannel. The turbulences generated by split mixing vanes has small length scales so that they maintain only about $10D_H$ after the spacer grid. On the other hand, the turbulences generated by the large scale vortex motions continue longer and remain up to $25D_H$ after the spacer grid.

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Turbulent Enhancement of the Cooling System of Nuclear Reactor by Large Scale Vortex Generation in a Nuclear Fuel Bundles (원자로 연료봉내 대형 와유동에 의한 원자로 냉각제 시스템의 난류 증진)

  • 전건호;박종석;최영돈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.11
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    • pp.1004-1011
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    • 2000
  • Experimental and computational studies were carried out to confirm the turbulent enhancement of the cooling system of nuclear reactor by large scale vortex generation in nuclear fuel bundle. The large scale vortex motions were generated by rearranging the inclination angles of mixing vanes to the coordinate directions. Axial development of mean and turbulent velocities in the subchannels were measured by the 2-color LDV system. Eddy diffusivity heat flux model and $k-varepsilon$ model were employed to analyze the turbulent heat and fluid flows in the subchannel. The turbulence generated by split mixing vanes has small length scales so that they maintain only about $10 D_H$ after the spacer grid. On the other hand, the turbulences generated by the large scale vortex continue more and remain up to $25 D_H$after the spacer gird.

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Development of Passive-Type Daylighting System for Large Space (대공간 적용을 위한 패시브형 자연채광시스템 개발)

  • Sung, Tae-Kyung;Park, Yeon-Min;Kim, Joung-Min;Lee, Chung-Sik;Lee, Euol-Young;Joung, Che-Bong;Kim, Byung-Chul
    • Journal of the Korean Solar Energy Society
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    • v.35 no.5
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    • pp.1-10
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    • 2015
  • Whereas recent domestic buildings and industrial facilities are being constructed as large as possible, the daylighting systems for the large space have rarely been developed. Domestic situation has been reported as only several small or medium sized daylighting systems have been developed, and the large scaled systems have entirely being imported from abroad. We have developed a large scaled daylighting system for the big space. The developed system have been evaluated in terms of the average system efficiency and daylighting factor. Each results are shown with tabulated experimental data.

Development of Integrated Transportation Analysis System for Large-scale event (대형 이벤트 대응형 통합교통분석 시스템 개발)

  • Lim, Sung-Han
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.3
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    • pp.1-9
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    • 2014
  • This study deals with development of Integrated Transportation Analysis System for Large-scale event. Based on case studies, the requirements of the system were defined and the direction of development was established. The large-scale events that require fast and accurate transportation policy were selected. The data warehouse and data mart were developed by integrating the large-scale event data and the traffic data. Business intelligence system was designed and developed users to allow timely decisions.

Operational Strategy for a BESS-based Microgrid (BESS 기반 마이크로그리드 운영전략)

  • Lee, Ha-Lim;Chun, Yeong-Han
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.12
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    • pp.1666-1672
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    • 2015
  • Small islands are quite adequate places where microgrid system with renewable sources can replace diesel engines as operation costs of diesel engine in most small islands are very high. To get the large amount of renewable energy, the microgrid system has very large capacity of renewable sources. The system with large capacity of renewable sources can meet the case when supplied energy is greater than the load and the fluctuation of source output is very large. The battery energy storage system can be a solution to stabilize the system with large capacity of renewable sources. In this case, BESS can be utilized as a master source for the synchronous operation of all sources including diesel engine, wind turbine and PV. The diesel generators can be used as a backup in case the BESS SOC goes below a certain level. In this paper, we suggest a novel unit commitment of diesel generators and operation schedule of pump for water supply service with the information of wind forecast, PV forecast, and load forecast. The proposed methods has been implemented and tested at the test bed in Gasa-Island.

A study on the techniques of large scale chemical process system analysis (화학공정에 있어서의 대규모공정 해석방법)

  • 조인호;문장호;윤인섭
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.560-565
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    • 1986
  • For the control of chemical process, optimal value of the process should be known at first. And process simulation is the previous step of optimal value calculation. However it is not a simple work to analyze chemical process system. Especially for the large scale chemical process system, many difficulties such as non-linearity and complexity caused by recycle streams should be overcome. In this paper, three strategies of large scale chemical process analysis were explained and discussed with case studies.

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A Study on the Establishment of an Integrated Management System for Forest Fire Prevention and Suppression Measures (산불예방 및 진압대책의 통합관리체계 구축 방안 연구)

  • Lee, Jeong-Il
    • Journal of the Korea Safety Management & Science
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    • v.24 no.2
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    • pp.163-169
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    • 2022
  • Recently, in Korea, if a very large forest fire occurs due to the people's carelessness, it is of great interest because it spreads into a large forest fire. If a wildfire spreads and becomes large, it will inflict great damage (appointment and property), and the damage is irreversible. The best way to extinguish a wildfire is to prevent it before it occurs. If a forest fire occurs due to a failure in prevention, the early firefighting activities to prevent the progress of the forest fire by promptly dispatching it by reporting it and approaching the site as soon as possible should now be managed with a systematic integrated management system. To do so, it is necessary to prepare a preventive system, such as issuing warnings for each weather condition by the Korea Forest Service, consisting of cooperation (support) activities for forest fire prevention by related organizations, etc. In order to minimize the loss of precious lives and forests, measures have been taken to establish a system, to establish a prompt and accurate situation reporting system, and to establish an integrated command system (ICS) for on-site commanders.

A Study on the Application of Fire Protection Facilities in Large Enclosure Gymnasium (대규모 실내경기장의 소방방재설비 적용현황 분석)

  • Choi, Dong-Ho;Kim, Choon-Dong;Yang, Jeong-Hoon;Cho, Young-Hum
    • Journal of Korean Association for Spatial Structures
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    • v.10 no.2
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    • pp.135-145
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    • 2010
  • The objective of this study is to draw basic data for the application of the fire protection planning for the future plan large enclosure buildings in Korea through an analysis of its characteristics by case studies of the domestic and foreign large scale gymnasiums. In this study, domestic building codes for the fire protection are investigated and fire detection systems, fire extinguishing systems, smoke control systems and evacuation systems of three large scale gymnasiums located at Korea and eight foreign countries are compared and analyzed. The results of this study show that infrared light fire detection system and flame detector for spacial characteristics are potentially used in fire protection systems of large scale gymnasiums: dry type sprinkler and sprinkler water gun are adopted in fire detection system; and smoke accumulation system is widely utilized in smoke control system.

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