• Title/Summary/Keyword: protection

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Estimating the Failure Rate of Protection System Using a Discrete Markov Model (이산 마코프 모델을 이용한 보호 시스템의 고장 비율 추정)

  • Shin, Jung-Jin;Lee, Hee-Tae;Kim, Jae-Chul
    • Proceedings of the KIEE Conference
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    • 2008.11a
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    • pp.385-387
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    • 2008
  • When a fault occurs in the distribution system, it is detected by protection system, then protection system is opened and de-energises the feeder where the fault exists. in this paper, the failure rate of protection system will estimate that using a discrete markov approach with failure data of protection system in order to improve the reliability of protection system.

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Design Golas for the Space Shuttle's Thermal Protection System (Space shuttle의 Thermal Protection System의 설계 목표)

  • 김선규
    • Journal of Astronomy and Space Sciences
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    • v.1 no.1
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    • pp.35-39
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    • 1984
  • The design of the reusable thermal protection system for the space shuttle orbiter using silica tile played one of key roles in the successful flight of the Columbia and subsequent space shuttles. The basic design goals for this thermal protection system were identified. Manufacturing procedures for the silica tile and the structure of the tile system were also described.

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The Historical Development of Consumer Protection

  • Alharthi, Saud Hamoud
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.392-398
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    • 2022
  • Consumers are continually in need of protection both locally and globally. The importance of providing consumer protection stems from the fact that the consumer represents the weaker party in the contractual process. This research focuses on examining the extent to which Saudi Law guarantees the protection of consumers using e-commerce from the expected legal problems such as antifraud locally and globally.

A Selective Protection Scheme for Scalable Video Coding Based on Dependency Graph Model

  • Hendry, Hendry;Kim, Munchurl
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2010.11a
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    • pp.78-81
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    • 2010
  • In this paper, we propose an efficient and effective selective protection scheme to SVC that exploit the propagation of protection effect by protecting significant frames that can give the maximum visual quality degradation. We model SVC dependency coding structure as a directed acyclic graph which is characterized with an estimated visual quality value as the attribute at each node. The estimated visual quality is calculated by using our model based on the proportions of intra- and inter-predicted MBs, amounts of residual, and estimated visual quality of reference frames. The proposed selective protection scheme traverses the graph to find optimal protection paths that can give maximum visual quality degradation. Experimental results show that the proposed selective protection scheme reduces the required number of frames to be protected by 46.02% compared to the whole protection scheme and 27.56% compared to the layered protection scheme.

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A Study on the Housewives' Clothing Behavior for the Environmental Protection (주부들의 환경보전을 위한 의생활행동)

  • 김용숙;신상옥
    • Journal of the Korean Society of Costume
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    • v.39
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    • pp.271-281
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    • 1998
  • The purposes of this study were to deter-mine the dimensions of the housewives' cloth-ing behavior for the environmental protection and the identify the effective variables. The results of this study was intended to provide fundamental material for the establishment of clothing behavior guidelines for the environmental protection. This study was conducted by reference analysis and empirical study. To develop theoreti-cal framework study. To develop theoreti-cal framework of dimensions of environmental protection behavior, references concerned were analyzed. The results of reference analy-sis showed that the dimensions of environmental protection bahavior were resource and energy saving, sold waste reduction, resource reuse or recycle, and green product purchase. The dimensions of housewives' clothing behavior for environmental protection were identified by use of self-administered questionnaires. The results of enpirical study showed that the dimensions of clothing behavior for the environmental protection wre clothing resource reuse or recycle, clothing management resource saving, clothing consumption resource saving, green product purchase, and clothing management resource saving was the highest and that of resource reuse or recycle was the lowest. Environmental consciousness, taking environmental education or not, residing place, clothing seperate-collectiong at residing place were effective variables on clothing behavior for environmental protection.

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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.

Over-Excitation Protection Relaying using the 345kV Power System Modeling Data (345kV 계통 모델링 데이터를 활용한 과여자 보호계전기법)

  • Park, Chul-Won;Ban, Yu-Hyeon
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.60 no.4
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    • pp.175-180
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    • 2011
  • A large AC generator is an important component of the power system. It is a need for research of AC generator protection relay for the next-generation ECMS and an efficient operation of protection control system. However, most of protection and control systems used in power plants have been still imported as turn-key and operated in domestic. This may cause the lack of the correct understanding on the protection systems and methods, and thus have difficulties in optimal operation. In this paper, over-excitation protection relaying is one of the protective factors in generator protection IED was presented. The cause and protection principles were dealt and, DFT-based gain compensation algorithm was adopted for the frequency measurement. The Republic of Korea 345kV modeling data by EMTP-RV was used for performance evaluation.