• Title/Summary/Keyword: Protection systems

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Interstory-interbuilding actuation schemes for seismic protection of adjacent identical buildings

  • Palacios-Quinonero, Francisco;Rubio-Massegu, Josep;Rossell, Josep M.;Rodellar, Jose
    • Smart Structures and Systems
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    • v.24 no.1
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    • pp.67-81
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    • 2019
  • Rows of closely adjacent buildings with similar dynamic characteristics are common building arrangements in residential areas. In this paper, we present a vibration control strategy for the seismic protection of this kind of multibuilding systems. The proposed approach uses an advanced Linear Matrix Inequality (LMI) computational procedure to carry out the integrated design of distributed multiactuation schemes that combine interbuilding linking devices with interstory actuators implemented at different levels of the buildings. The controller designs are formulated as static output-feedback H-infinity control problems that include the interstory drifts, interbuilding approachings and control efforts as controlled-output variables. The advantages of the LMI computational procedure are also exploited to design a fully-decentralized velocity-feedback controller, which can define a passive control system with high-performance characteristics. The main ideas are presented by means of a system of three adjacent five-story identical buildings, and a proper set of numerical simulations are conducted to demonstrate the behavior of the different control configurations. The obtained results indicate that interstory-interbuilding multiactuation schemes can be used to design effective vibration control systems for adjacent buildings with similar dynamic characteristics. Specifically, this kind of control systems is able to mitigate the vibrational response of the individual buildings while maintaining reduced levels of pounding risk.

A Study on Design of IED for Generator Protection Panel (발전기보호반을 위한 IED의 설계에 관한 연구)

  • Park, Chul-Won;Park, Sung-Wan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.3
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    • pp.133-138
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    • 2013
  • A large generator is an important role in transferring an electric power to power system. The IEDs of large generator often use microprocessor technology to obtain a digital relay system with a wide range of measuring, protection, control, monitoring, and communication functions. However, all generator protection and control systems in Korea imported from abroad and are being operated. In order to reduce the large expense and improve the reliable operation, development of generator protection and control system by domestic technology is required. This paper deals with the design of the IED of generator protection panel for development of generator protection and control system. The major emphasis of the paper will be on the description of hardware and signal processing test results and measurement accuracy of the prototype IED. By developing of generator IED based on DSP and microprocessor, replacement of the generator protection panel imports are expected to be effective.

Protection Distance Calculation Between Inductive Systems and Radiocommunication Services Using Frequency Below 30 MHz (30 MHz 이하에서 무선 서비스와 유도성 시스템 간의 보호 거리 산출)

  • Shim, Yong-Sup;Lee, Il-Kyoo;Park, Seung-Keun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1211-1221
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    • 2012
  • This paper describes separation distance to protect radiocommunication services from the interference of inductive systems using frequencies below 30 MHz for the co-existence between radiocommunication services and inductive systems. For the analysis, the interference scenario model is proposed between inductive system and radiocommunication services. Then the calculation method of protection distance is suggested by comparing the radiation power of inductive system with the allowable interference level of victim services, radiocommunication services, according to the applied propagation model. Also, the protection distance for protecting radiocommunication services in the 30 MHz below is calculated through the interference analysis from RFID(Radio Frequency IDentification) and PDP(Plasma Display Panel) TV based on the suggested method. The proposed calculation method was adopted as ITU-R recommendation in related with resolution 63 at ITU-R SG(Study Group) 1 meeting in June, 2012. It will be available to use for the protection of radiocommunication services from the interference of wireless power transfer system and power line telecommunication system.

A Study on Investigation into Actual Condition of Management in Fire Protection System -Apartment Buildings, Shopping Center, Office Buildings- (소방시설 관리실태조사에 관한 연구 -공동주택, 상가건축물, 사무소건축물-)

  • 김홍배;한상민;이영재;조병선
    • Fire Science and Engineering
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    • v.15 no.3
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    • pp.70-76
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    • 2001
  • In a daily life these days, the safety and the comfort are considered very important. As the same as other areas, the good maintenance of fire protection systems and the fire drill plans in buildings can minimize the loss of human life and the property in case of fires. In this paper, a survey has been conducted to investigate the maintenance status of the fire protection systems of apartment buildings, shopping center and office buildings. Both practical procedures for checking the systems and for fire drills and strategic plans to minimize the losses in case of fires are suggested by analyzing how well the occupants in the buildings acknowledge the evacuation drills when the fire occurs.

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Protection Techniques Against Electric Shock in Low Voltage DC Grounding Systems Depending on the Analysis of Earth Fault Current Paths (저압직류 접지시스템의 지락경로 흐름 분석에 따른 감전 보호기법)

  • Kim, Dong-Woo;Lim, Young-Bea;Lee, Sang-Ick;Choi, Myeong-Il;Moon, Hyun-Wook
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.1
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    • pp.232-238
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    • 2016
  • This paper presents protection techniques against electric shock in low voltage DC(direct current) grounding systems depending on the analysis of earth fault current paths. Firstly, the comparison between alternating current and direct current on human was conducted, and current threshold values for each current path and for long duration were analyzed. Secondly, the analyses of the earth fault current flows were performed depending on the grounding types and earth fault conditions. Lastly, based on these analyses, adequate protection measures of electric shock depending on low voltage DC grounding types were provided.

Practical Experiences with Corrosion Protection of Water Intake Gates in Mekong River

  • Phong, Truong Hong;Tru, Nguyen Nhi;Han, Le Quang
    • Corrosion Science and Technology
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    • v.7 no.6
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    • pp.328-331
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    • 2008
  • Corrosion behaviour of water intake gate steel structures with different protective measures was investigated. Five material alternatives were taken for investigation, including: imported and recycled stainless steel, carbon steel with hot zinc spraying, painting and composite coatings. Results of corrosion rate for carbon steel, SUS 304, hot zinc spray coats in three water systems of Mekong river basin (saline, blackish and fresh) were also presented. Corrosion rate of carbon steel decreased with decreasing salinity in the investigated water environments. Meanwhile, these values for zinc coated steel, behaved by another way. Environmental data for these systems were filed and discussed in relation with corrosion characteristics. Method of Life Cycle Assessment (LCA) was applied in materials selection for water intake gate construction. From point of Life Cycle Cost (LCA) the following ranking was obtained: Zinc sprayed steel < Recycled stainless steel < Composite coated steel < Painting steel < SUS 304 From investigated results, hot zinc spray coating has been applied as protective measure for steel structures of water intake systems in Mekong river basin.

석유화학공장의 소화설비에 대한 고찰

  • Lee, Hyeong-Seop
    • Fire Protection Technology
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    • s.12
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    • pp.21-30
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    • 1992
  • This fire fighting systems engineering specification includes the design and installation requirements which normally adopted for petroleum refineries and petrochemical industries. Also, this shall be applied the Korean Fire Safety Law, in addition to the Korean Industry Safety & Health Law and NFPA Code.

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A Lightning Surge Analysis of Testing Line for Protection of Underground Distribution Systems (지중배전계통 보호를 위한 모의시험선로 서지특성 해석)

  • Kim Byoung-Sung;Lee Jang-Geun;Lee Jong-Beom;Han Byong-Sook
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.8
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    • pp.313-321
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    • 2006
  • This paper describes the overvoltage obtained by surge behavior analysis in testing underground distribution systems. Model systems consist of overhead distribution line and underground cable. Such model system considered various characteristics of actual distribution systems will be soon constructed at testing yard. Simulation is carried out under various states such as cable kinds, cable length, lightning wave and time, and branch circuits. Model is established by EMTP/ATPDraw. Line Constants are calculated by ATP_LCC. When the direct lightning surge strikes on conductor of overhead line, the overvoltage is calculated using EMTP/ATPDraw in many cases. Simulation results will be compared with real testing results at testing yard in the near future. The compared results will be used to establish protection methods in actual underground distribution systems.

UEP Effect Analysis of LDPC Codes for High-Quality Communication Systems (고품질 통신 시스템을 위한 LDPC 부호의 UEP 성능 분석)

  • Yu, Seog Kun;Joo, Eon Kyeong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.6
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    • pp.471-478
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    • 2013
  • Powerful error control and increase in the number of bits per symbol should be provided for future high-quality communication systems. Each message bit may have different importance in multimedia data. Hence, UEP(unequal error protection) may be more efficient than EEP(equal error protection) in such cases. And the LDPC(low-density parity-check) code shows near Shannon limit error correcting performance. Therefore, the effect of UEP with LDPC codes is analyzed for high-quality message data in this paper. The relationship among MSE(mean square error), BER(bit error rate) and the number of bits per symbol is analyzed theoretically. Then, total message bits in a symbol are classified into two groups according to importance to prove the relationship by simulation. And the UEP performance is obtained by simulation according to the number of message bits in each group with the constraint of a fixed total code rate and codeword length. As results, the effect of UEP with the LDPC codes is analyzed by MSE according to the number of bits per symbol, the ratio of the message bits, and protection level of the classified groups.