• Title/Summary/Keyword: Protection System

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Lightning Risk Assessment for Structures Lower than 20m High (높이 20미터 미만인 구조물의 낙뢰리스크 평가)

  • Lee, Ju-Chul;Kim, Gi-Hyun;Lee, Young-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.12
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    • pp.21-27
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    • 2012
  • Korean Industrial Standards for lightning protection system complies with IEC standards. However, the standards are applicable only to buildings and structures more than 20 meters in high. Therefore, it is necessary to determine whether lightning protection system should be installed on structures lower than 20 meters high. This paper proposes an efficient method of assessing risk against lightning of structures lower than 20 meters high. The method suggests simplified lightning protection system and provides selecting an appropriate protection level. The suggested method assumes that structure under assessment has no lightning protection system and there is no person around the structure at the moment of lightning stroke. A simplified method of assessing the risk to human within the structure is developed by adopting the general assessment factor. The selection of a protection level is possible by comparing tolerable risk with physical damage risk caused by a direct lightning. Finally, this paper gives ways to establish surge protection measures when a structure with lightning risk is within a radius of 2km from the assessed structure even if this structure requires no lightning protection system.

Perception differences between users and policy-makers on technology protection support system for small and medium-sized businesses (중소기업 기술보호지원제도에 대한 이용자와 정책담당자의 인식차이 분석)

  • Park, Sanghoon;Cho, Namwook
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.1
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    • pp.37-48
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    • 2017
  • As the risk of technical leakage is increasing, technology protection support systems for small and medium-sized businesses have gained attention. This paper analyzed the perception gap of the user and policy-maker regarding technology protection support systems. First, to identify key elements of technology protection support systems and construct measurement factors, interviews with experts are conducted. Then, surveys are conducted to analyze the perception differences between the users and policy-makers. Factor analysis and ANOVA have been utilized to analyze survey results. The result shows that the perception gaps exist in the following areas: management system, cost reduction, copyright protection, customer satisfaction, leakage prevention, and awareness. To enhance the effectiveness of technology protection support systems, this paper suggests technology protection support systems should be customized in terms of the company's size and type of busines.

A Novel Procedure for Protection Setting in an HVDC System Based on Fault Quantities

  • Gao, Benfeng;Zhang, Ruixue;Zhang, Xuewei
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.513-521
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    • 2017
  • HVDC protection setting is difficult to be calculated analytically because of its strong nonlinearity. The currently used setting method is based on the empirical setting of previous projects and then verified by digital simulation. It entails a huge workload and low efficiency. To facilitate protection setting, this paper systematically summarizes the HVDC protection characteristics and then presents a classification of HVDC protections according to the protection principles. On the basis of the fault quantities, a novel setting procedure suitable for travelling wave protection, derivative and level protection, and differential protection is proposed. The proposed procedure is illustrated and verified in detail with the example of travelling wave protection. An HVDC protection setting system that has the functions of automatic protection setting and data management is developed utilizing the C# programming language.

Fire Protection system using CAN (CAN을 이용한 소방 시스템)

  • Choi S. I.;Kim Y. D.;Kang W. C.;Kim Y. H.;Oh G. G.
    • Proceedings of the KIPE Conference
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    • 2004.07a
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    • pp.167-171
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    • 2004
  • In this Paper, We are going to propose the fire protection system with using CAN(Controller Area Network). The larger, higher and deeper buildings are, the more dangerous people are when fire happens. We are aware of the problems of prior Fire protection system. Therefore, we construct embedded system based on CAN communication that is capable of N:N communication, and build independent Fire protection system.

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Study on the Liquid Rocket Engine Health Monitoring and Emergency Protection System (액체로켓엔진 상태진단/비상보호시스템 연구)

  • Kim, Seung-Han;Nam, Chang-Ho;Seol, Woo-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.178-182
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    • 2007
  • This paper reviews on the LRE health monitoring and emergency protection system to protect test object engine system and engine test facility, in case of various fault occurrence at LRE testing. General composition and major technical consideration of LRE health monitoring system and emergency protection system are reviewed. Moreover, some application of LRE health monitoring/emergency protection system to development test of major LRE component such as turbopump testing, gas generator and combustion chamber test are reviewed.

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Multi-Agent System having Adaptive Over Current Protection Function for Power Distribution Systems (멀티 에이전트 시스템 (Multi-Agent System)을 이용한 배전계통의 적응 과전류보호)

  • Chang, Choong-Koo;Lee, Seung-Jae;Lim, Dong-Jin
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.8
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    • pp.365-372
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    • 2001
  • This paper presents a new protection concept to achieve the adaptive optimal function by introducing the multi-agent system technology. Making each relay an agent which consists of relay agent module and coordinator module, each agent works autonomously to improve protection capability by cooperating with other agents. It is applied to the overcurrent protection system of the industrial power system in order to show the feasibility of the proposed methodology.

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RPS Periodic Testing Method for Reliability and Availability (신뢰성과 유지보수를 위한 원자로보호계통 주기시험 방법 개발)

  • Park, Joo-Hyun;Lee, Dong-Young;Lee, Seong-Jin;Song, Deok-Yong
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.84-86
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    • 2005
  • The digital systems such as PLC or DCS have been applied to non-safety systems of nuclear power plants because of many difficulties in using analog systems. Nowadays, digital systems have been applied to safety systems of the plants such as reactor protection system. One of the main advantages of digital systems is applicability of automatic testing methods to the systems. The protection system requires high-reliability and high-availability because it shall minimize the propagation of abnormal or accident conditions of nuclear power plants. The calculation of reliability and availability of systems depends on the maintenance period of the system. In general, the maintenance period of the protection system is one-month in case of the manual test. However, the cycle of test can be shortened in several hours by using automatic periodic testing. The reliability and availability of the system is better when test period is shortened because the reliability and availability is inverse proportion to the test period. In this research, we developed the automatic periodic testing method for KNICS Reactor Protection System, which can test the system automatically without an operator or a tester. The automatic testing contained all functions of reaction protection systems from analog-to-digital conversion function of the bistable Processor to the coincident trip function of the coincident processor. By applying the automatic periodic testing to reaction system, the maintenance cost can be cut down and the reliability can be increased.

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The development study on the power system operation and protection scheme in Myanmar (미얀마 전력계통 운영 및 보호시스템 구축 사업)

  • Kim, Jong-Hwa;Choi, Young-Sung;Han, Seong-Min;Lee, Duck-Jae
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.34-35
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    • 2008
  • KEPCO conducted a third project in Myanmar regarding system operation and protection scheme. This paper deals with blackout reduction plan, reactive power compensation plan and system restoration procedures in operations parts. Moreover protection system improvement plan and standard protection schemes were suggested.

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Investigation of Design Methodology for Impressed Current Cathodic Protection Optimum System

  • Yao, Ping;Wu, Jianhua
    • Corrosion Science and Technology
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    • v.7 no.4
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    • pp.197-200
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    • 2008
  • In this paper, physical scale modeling was employed to identify the configurations of ICCP system and the electric field signatures. Computational boundary element modeling technique has been used to simulate the performance of the CP system and to predict the associated electric fields signatures. The optimization methods combined with the computer models and physical scale modeling will be presented here, which enable the optimum system design to be achieved both in terms of the location and current output of the anode but also in the location of reference electrodes for impressed current cathodic protection(ICCP) systems. The combined methodology was utilized to determine optimal placement of ICCP components (anodes and reference electrodes) and to evaluate performance of ICCP system for the 2%, 10% and 14% wetted hull coatings loss. The objective is to design the system to minimise the electric field while at the same time provide adequate protection for the ship. The results show that experimental scale modeling and computational modeling techniques can be used in concert to design an optimum ICCP system and to provide information for quickly analysis of the system and its surrounding environment.

Immune Protection Factor of Sunscreens in Humans is Dependent on Protection from UVA and Cannot be Predicted from the Sun Protection Factor

  • Halliday, Gary M.;Poon, Terence S.C.;Damian, Diona L.;Barnetson, Ross St.C.
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.236-239
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    • 2002
  • Sunscreens have been advocated as an important means of preventing skin cancer. UV-induced immunosuppression is important for skin cancer development, yet the effectiveness of sunscreens in protecting the human immune system from UV radiation is unclear. The only currently accepted method of sunscreen rating is the Sun Protection Factor (SPF) based on prevention of erythema. We developed an in vivo non-invasive method for evaluating protection of the human immune system from UV radiation based on recall contact sensitivity to nickel, a common allergen. Using this system we showed that broad-spectrum sunscreens provide greater protection to the immune system than sunscreens which protect from UVB only. UVA was found to be immunosuppressive. We developed this technique to enable the study of solar simulated UV radiation dose responses and determined Immune Protection Factors (IPFs) for six commercially available sunscreens based on limits of protection from the dose response data. We found that the IPF did not correlate with the SPF and that protection from erythema therefore cannot be used to predict protection of the immune system. However, IPF was significantly correlated to the UVA protective capability of the sunscreens, indicating that sunscreen protection from UVA is important for prevention of immunosuppression. We recommend that sunscreens should be rated against their immune protective capability to provide a better indication of their ability to protect against skin cancer.

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