• Title/Summary/Keyword: Protection systems

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Performance Evaluation of Protection against Electric Shocks for TT and TN Systems (TT, TN접지계통의 감전보호 성능평가)

  • Lee, Bok-Hee;Choi, Young-Chul;Yoo, Jae-Duk;Shin, Hee-Kyung;Yang, Soon-Man;Kim, Tae-Gi;Lee, Zu-Cheul
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.315-318
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    • 2009
  • Electric shock is the accident caused by the current through a person or animal's body. That is characterized by the physiological effects. In this paper, we evaluate performance of protection against electric shocks for TT and TN grounding systems which are used by a low voltage consumer nowadays. The performance of protection against electric shocks for TT grounding system is very excellent in equipotential area of the third class grounding, but the performance is poor outside the equipotential area. The performance of protection against electric shocks for TN grounding system is excellent because the potential difference is less than 50V. Accordingly, the performance of protection for TN grounding system is good as compared with that for TT grounding System.

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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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Advanced Protective Coordination Schemes of Utility Interconnected Cogeneration Systems (배전계통에 연계된 열병합발전 시스템의 개선된 보호협조 방안에 관한 연구)

  • Choe, Jun-Ho;Jeong, Seong-Gyo;Chu, Dong-Uk;Kim, Nak-Gyeong;Son, Hak-Sik;Kim, Jae-Cheol
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.6
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    • pp.280-288
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    • 2000
  • Recently, there has been growing interest in utilizing cogeneration(COGN) systems with a high-energy efficiency due to the increasing energy consumption and the lacking of energy resource. But an insertion of COGN system to existing power distribution system can cause several problems such as voltage variations, harmonics, protective coordination, increasing fault current etc, because of reverse power of COGN, especially in protective coordination. A study on a proper coordination with existing one is being required. The existing power distribution system is operated with radial type by one source and protection system is composed based on unidirectional power source. But an Insertion of COGN system to power distribution system change existing unidirectional power source system to bidirectional power source. Therefore, investigation to cover whole field of power distribution system must be accomplished such as changing of protection devices rating by increasing fault current, reevaluation of protective coordination. In this paper, simulation using PSCAD/EMTDC was accomplished to analyze effect of COGIN on distribution fault current. Also, the existing protection system of 22.9[kV] power distribution system and customers protection system to protect of COGIN was analyzed and the study on protective coordination between of two protection system accomplished.

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Performance Assessment for Rockfall Protection Systems II: Performance Assessment (낙석방지울타리의 성능평가 II: 성능평가)

  • Kim, Kee Dong;Ko, Man Gi;Kim, Dal Sung;Han, Ki Jang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.1
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    • pp.49-61
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    • 2015
  • This is the second of two companion papers that describe the performance assessment for flexible rockfall protection systems. Described in a companion paper is the criteria to assess the performance of flexible rockfall protection systems. In this study the performance assessment of domestic rockfall protection fences was implemented using the criteria suggested in the companion paper. It was investigated that the rockfall protection fences for express highways performed well to resist the rockfall energy of 50kJ and the deformed rockfall protection fences right after impacting would not obstruct the vehicle traffic. However, to dissipate the rockfall energy of 50kJ with the level of European standards constantly, the spacing of wireropes was adjusted to be 200mm up to the 8th wirerope from the bottom and spacing-maintainers should be extended to the 8th wirerope. It was figured out that the rockfall protection fences for general highways were required to install spacing-maintainers as those for express highways because they, which did not have spacing-maintenance members, were very prone to the penetration of rockfall even for the very small rockfall impact energies.

Establishment of a secure networking between Secure OSs

  • Lim, Jae-Deok;Yu, Joon-Suk;Kim, Jeong-Nyeo
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2097-2100
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    • 2003
  • Many studies have been done on secure operating system using secure kernel that has various access control policies for system security. Secure kernel can protect user or system data from unauthorized and/or illegal accesses by applying various access control policies like DAC(Discretionary Access Control), MAC(Mandatory Access Control), RBAC(Role Based Access Control), and so on. But, even if secure operating system is running under various access control policies, network traffic among these secure operating systems can be captured and exposed easily by network monitoring tools like packet sniffer if there is no protection policy for network traffic among secure operating systems. For this reason, protection for data within network traffic is as important as protection for data within local system. In this paper, we propose a secure operating system trusted channel, SOSTC, as a prototype of a simple secure network protocol that can protect network traffic among secure operating systems and can transfer security information of the subject. It is significant that SOSTC can be used to extend a security range of secure operating system to the network environment.

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The Development and the Performance Test of Bay Controller for the High-Voltage Gas Insulated Switchgear (초고압 가스절연개폐기의 베이 컨트롤러 개발 및 성능시험)

  • Woo, Chun-Hee;Lee, Bo-In
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.2
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    • pp.179-184
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    • 2010
  • The digital substation automation system has contributed hugely to increasing the stability of power systems by providing not only protection and control of power systems but diagnostic features alongside them. Digital substation automation systems in the scale of substations consist of integrated operation systems and intelligent electronic devices. The main intelligent electronic devices currently in use are digital protection relays and the bay controllers in Gas insulated switchgears. Proficiently accomplishing the coordination of protection within the power system as a means of ensuring reliability and contriving for the stability of power supply through connection of function, the application of bay controllers is crucial, which collectively manage the protection relay at the bay level in order to achieve both. In this research, the bay controllers to be used in high-voltage Gas insulated switchgear has been localized, and in particular, the logic function and editor required in order to minimize the complicated hardware-like cable connections in the local panel have been developed. In addition, to ensure the strength and reliability of the bay controller hardware developed herein, the type tests from KERI have been successfully completed.

A Protection Profile for Access Control Based Database Security System (접근제어형 데이터베이스 보안 시스템의 보호프로파일)

  • Jeon, Woong-Ryul;Jo, Hea-Suk;Kim, Seung-Joo;Won, Dong-Ho
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.1
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    • pp.109-113
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    • 2007
  • With increasing the mont of processed information over the network, the importance of database system increases rapidly. There are two types of security system for database, access control and data encryption. However, it is hard to evaluate security of database systems using the Common Criteria(CC) as there is no protection profile(PP) for these systems. In this paper, we propose a protection profile for secure database systems which can be used in formal evaluation using the Common Criteria. The proposed protection profile can be used by both developer and consumer to evaluate security of database systems.

Derivation of Anti-Tamper System Requirements Based on CMVP Standard for Technology Protection of Weapon Systems (무기 시스템의 기술 보호를 위한 CMVP 표준 기반의 Anti-Tamper 시스템 요구사항 도출)

  • Lee, Min-Woo;Lee, Jae-Chon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.470-478
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    • 2019
  • As the growth of the domestic defense industry is remarkable regarding technology level and export size, technology protection is necessary. Particularly, there is a need to apply anti-tamper measures to prevent critical technologies from illegally being taken out of weapon systems. However, there is no security protection strategy and system built yet in ROK. Precedent studies discussed the trend analysis and technical research for specific protective techniques, and the application of anti-tamper using limited procedures was provided. Recently, methods of how to select the technology for protection were studied based on risk management. Nonetheless, these studies cannot be associated with the acquisition process for the whole life-cycle, having difficulty with actual development and evaluation of the weapon systems. The objective of our study is to derive the system requirements of the weapon system for which anti-tamper measures have been determined to apply. Specifically, requirements items suitable for the development of anti-tamper weapon systems were derived based on ISO/IEC 19790, the CMVP standard for the development and verification of cryptographic modules. Also, its utilization in technical reviews and test & evaluations was presented. The usefulness of the research results was confirmed through inductive inference and comparative evaluation. The result can be expected to play a role in initiating extensive activities needed for technology protection of the weapon systems.

The Structural Relationships among Information Security Threat Factors and Information Protection Behavior of the FinTech Services: Focus on Theoretical Perspectives of Technology Threat Avoidance and Health Protective Behaviors (핀테크(FinTech) 서비스의 정보보안 위협요인과 개인정보보호행위와의 구조적 관계에 관한 연구: 기술위협회피와 건강행동이론 관점에서)

  • Bae, Jae Kwon
    • The Journal of Information Systems
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    • v.26 no.3
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    • pp.313-337
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    • 2017
  • Purpose Financial technology, also known as FinTech, is conceptually defined as a new type of financial service which is combined with information technology and other traditional financial services like payments, investments, financing, insurance, asset management and so on. Most of the studies on FinTech services have been conducted from the viewpoint of technical issues or legal and institutional studies, and few studies are conducted from the health belief perspectives and security behavior approaches. In this regard, this study suggest an extended information protection behavior model. Design/Methodology/Approach The Health Belief Model (HBM), the Protection Motivation Theory (PMT), and the Technology Threat Avoidance Theory (TTAT) were employed to identify constructs relevant to information protection behavior of FinTech services. A new extended information protection behavior model in which the influence factors of information protection behavior (i.e., perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived self-efficacy, subjective norms) affect perceived threats and perceived responsiveness positively, leading to information protection behavior of FinTech users eventually. This study developed an extended information protection behavior model to explain the protection behavior intention in FinTech users and collected 272 survey responses from the mobile users who had experiences with such mobile payments and FinTech services. Findings The finding of this study suggests that the influence factors of information protection behavior affect perceived threats and perceived responsiveness positively, and information protection behavior of FinTech users as well.

Problem Analysis of Power Capacity and Main Line Voltage Drop of Electric Power System for Fire Protection (소방전원계통의 전원용량과 간선의 전압강하에 대한 문제점 분석)

  • Choi, Seung-Kyou;Son, Bong-Sei
    • Fire Science and Engineering
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    • v.29 no.3
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    • pp.53-58
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    • 2015
  • The number of high-rise buildings and skyscrapers has increased drastically, and accordingly, the power capacities and main line lengths of electric power systems for fire protection are also rapidly increasing. This is generating new of problems like shortages in power capacities and increases of main line voltage drops outside of the rated voltage range. This problem can have serious effects on fire protection systems and a variety of electric devices may not work properly in emergencies. As such, theoretical calculations were performed for these systems in an actual fire protection facility. The problems in the electric power system were extracted and analyzed, and the results show that it is necessary to search for new measures for the safe and rational design and operation of electric power systems for fire protection.