• Title/Summary/Keyword: protection system

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조사연구-공기흡입 화재탐지설비(ADS)에 대한 고찰

  • Ryu, Eun-Yeol
    • Fire Protection Technology
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    • s.19
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    • pp.17-21
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    • 1995
  • This is to study installation standards of aspirating devices and detectors, which are components of ADS(aspirating fire detection system). The BFPSA(British Fire Protection System Association) code was mainly referred is studying. ADS aspirated air and smoke through the pipe and then checks if there is fire or not. It is now in the limelight because it can early alarm in case of fire and prevent false-alarming.

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Overlay2 file system's Source Protection Methodology (Overlay2 파일 시스템의 소스 보호 방법에 관한 연구)

  • Han, Sung-Hwa
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.10
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    • pp.1397-1402
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    • 2021
  • The overlay2 file system is one of the union file systems that mounts multiple directories into one. The source directory used for this overlay2 file system mount has a characteristic that it operates independently of the write-able layer after mounting, so it is often used for container platforms for application delivery. However, the overlay2 file system has a security vulnerability that the write-able layer is also modified when file in the source directory is modified. In this study, I proposed the overlay2 file system protection technology to remove the security vulnerabilities of the overlay2 file system. As a result of empirically implementing the proposed overlay2 file system protection technology and verifying the function, the protection technology proposed in this study was verified to be effective. However, since the method proposed in this study is a passive protection method, a follow-up study is needed to automatically protect it at the operating system level.

Study of Practical Cathodic Protection of 2nd Class Stainless Steel Shaft by means of Al Sacrificial Anode (AL계 희생양극에 의한 2종스테인리스 강축의 음극방식 실용화 연구)

  • Son, Yeong-Tae;Lee, Myeong-Hun;Lee, Hui-Jun
    • Journal of Korea Ship Safrty Technology Authority
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    • s.22
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    • pp.34-53
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    • 2007
  • In the case of hull material. large sized merchant ships are made of steel, on the other hand FRP or wood are used for small sized fishing boats. At present in Korea approximately 88,500 fishing boats are in operation of which 70% are made of FRP In the meantime, stainless steel is frequently used as shaft materials of the small-size FRP fishing boat. Namely, the kinds of shaft materials are STS 304(18Cr-8Ni), STS 316(18Cr-12Ni-2.5Mo steel) and STS 630(17Cr-Ni-Nb steel)etc. Among these things, STS 304 which is the cheapest and having ordinary corrosion resistance is most widely used as 2nd class shaft material. But, using STS 304 for shaft system material of the small-size FRP fishing boat on seawater environments entails a severe corrosion which causes shaft system troubles. Particularly, the corrosions tend to be concentrated of the stern and bow side, propeller shaft surface of inside of stern tube and the boat having no stern cooling pipe line system. As a solution for those problems, research on the ways to mitigate corrosion on the part of 2nd class stainless steel shaft have been undertaken. In the result, not only clarification for the reason of corrosion of the part of stainless steel shaft used mainly for the small-size FRP fishing boat was done, but also most optimal corrosion protection system was developed by experimenting shaft's protection simulation based of the electrochemical cathodic protection principle. In addition, verification through the field test on the optimal cathodic corrosion protection method by means of aluminum sacrificial anode was carried out. In this study, effective and economical shaft's protection system is suggested to the small-size FRP fishing boat operator by substantiating the results obtained from the research on the optimal cathodic protection.

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Characteristic Analysis and Configuration of the Protection System to Improve the Safety of the BIPV System (BIPV 시스템의 안전성 향상을 위한 보호시스템 구성 및 특성 분석)

  • Seok-Hwan Cho;Jae-Sub Ko;Dae-Kyong Kim
    • Journal of the Korean Society of Industry Convergence
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    • v.27 no.3
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    • pp.591-599
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    • 2024
  • This paper presents the configuration and characteristic analysis of the protection system to improve the safety of the building integrated photovoltaic(BIPV) system. BIPV is a solar power system installed in buildings. Since the BIPV system is installed in buildings, there is a high risk of electric shock and fire accidents. Therefore, in order to improve the safety of BIPV, a protective system is required to block or quickly detect risk factors. In this paper, as a protection system to improve the safety of the BIPV system, it is composed of a rapid shutdown (RSD) that can quickly separate the PV system to prevent fire and electric shock accidents and a system to detect Arc faults that cause PV system fires. RSD and Arc Fault Detector analyzed the operating characteristics according to each condition and confirmed that the safety of the BIPV system can be improved through this.

Advanced Cathodic Protection Modeling Associated with Coating Degradation Conditions

  • Im, Gwan-Jin;Kim, Ki-Joon;Lee, Myung-Hoon
    • Corrosion Science and Technology
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    • v.8 no.5
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    • pp.177-183
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    • 2009
  • There are two effective methods in use to protect ship ballast tank against corrosion. One is paint coating and the other cathodic protection(CP). The conventional cathodic protection design has mainly relied on the expert's experience. During the last two decades computer modeling has been significantly developed as an advanced design technology for cathoidic protection systems not only for ships, but also for offshore structures. However the present computer modeling of cathodic protection systems have some limitations simulating corrosion in the ballast tank with a deteriorated coating. In this study, "coating breakdown factor" considering coating degradation states with time has been attempted to improve the cathodic protection modeling using the data from literatures.

Improvement of Line Protection Methods by Dynamic Analysis on a FACTS-compensated transmission line (FACTS 보상 송전선의 동적 해석을 통한 송전선 보호 방안 개선)

  • Lim Jung-Uk;Runolfsson Thodur
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.54 no.12
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    • pp.573-579
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    • 2005
  • Dynamic analysis of a transmission line which is compensated by a FACTS device such as STATCOM, SSSC and UPFC is carried out in this paper and the impacts on conventional line protection methods such as the DCPM (Differential Current Protection Method) and the DPM (Distance Protection Method) are reviewed. A refined DCRM is proposed to detect faults properly regardless of the FACTS operation. The proposed method is applied to a FACTS-compensated line with a variety of faults and is verified by simulation results. An adaptive DPM on a FACTS-compensated line was proposed previously in the literature. In order to emphasize the necessity of the modified DPM, the conventional DPM is applied to a FACTS-compensated system. Significant factors such as fault types, fault locations, and fault resistances as well as FACTS device types are considered for relaying setting.

A Study of Euro NCAP Pedestrian Protection Protocol in Upper Leg Area (유럽 신차 안전도 평가방법을 적용한 보행자 대퇴부 상해 영향 분석)

  • Hyungjoon Oh;Hanchun Cho;Junyi Kim;Seungki Kim
    • Journal of Auto-vehicle Safety Association
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    • v.6 no.1
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    • pp.16-21
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    • 2014
  • Recently Korea and many countries are legislated for pedestrian protection as following the GTR(Global Technical Regulation). Most NCAP organization have been applying pedestrian protection results in their own rating system in individual or overall rating. Euro NCAP agency has been introduced it first. From the beginning, Euro NCAP had assessed occupant and pedestrian protection. It has become to strengthen a pedestrian protection protocol every time published. Korea NCAP also has been rating pedestrian protection with overall rating system. This paper proposed to study new pedestrian protection protocol especially upper leg in order to find injury response based on physical test. On Euro NCAP, the upper leg injury are assessed two kind of value which are bending moment and force.

A Study on the Protective Coordination of Generator Overexcitation and Overvoltage Relay (발전기 과여자 및 과전압 계전기 보호협조에 관한 연구)

  • Park, Ji-Kyung;Kim, Kwnag-Hyun;Kim, Chul-Hwan;Lyu, Young-Sik;Yang, Jeong-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.8
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    • pp.1187-1194
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    • 2017
  • After North American wide area black out on August 14, 2003, various studies have been conducted to find out the reason of the disaster. One of main reasons was misoperation of generator protection system. Since then, protective coordination between generator protection system and excitation system controls has been hot issue among electrical engineers. Among various generator protection relays, in this paper, we focused on generator overvoltage and overexcitation relay, which protect the over-flux condition of the generator. Thus, at first, we modeled the generator overvoltage, overexcitation relay and detailed power system including excitation system, governor and etc., based on actual field data. And then, we reviewed the protective coordination of generator overvoltage and overexcitation relay using electromagnetic transient program. In addition, we discussed the protective coordination method for redundant protection relays in both automatic voltage regulator and generator side.