• Title/Summary/Keyword: SIL4

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A Study on Architecture Design of Output Module for SIL4 Safety Related System (SIL4 안전관련 시스템에 적합한 출력 모듈의 구조 설계에 대한 연구)

  • Yoo, Deung-Ryeol;Hwang, Kyeng-Hwan;Lee, Key-Seo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.10
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    • pp.1079-1086
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    • 2015
  • This paper introduces the architecture of OUTPUT module that is suitable using in safety related system having SIL4 and proposes the quantitative target that is required for OUTPUT module. Especially, only output type that is made up Relay output signal and analog signal among various output ways is applied in output module that is a part of safety related system. The FMEA(Failure Modes and Effect Analysis), FTA(Fault Tree Analysis) are used as analysis method. As a result, it proposes to the architecture and failure frequency of the Output module that is used in SIL4 safety related system.

A Study on FMEDA Process for SIL Certification : A Case Study of a Flame Scanner (SIL 인증을 위한 FMEDA 프로세스 연구 : 화염검출기 사례를 중심으로)

  • Kim, Sung Kyu;Kim, Yong Soo
    • IE interfaces
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    • v.25 no.4
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    • pp.422-430
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    • 2012
  • In this article, we introduced the estimation method by 'Safety Integrity Level'(SIL) for the criterion of safety assurance and performed a case study on a flame scanner. SIL requires probabilistic evaluation of each set of equipment used to reduce risk in a safety related system. FMEDA(Failure Modes, Effects and Diagnostic Analysis) method is widely used to evaluate the safety levels and provides information on the failure rates and failure mode distributions necessary to calculate a diagnostic coverage factor for a part or a component. Basically, two parameters resulting from FMEDA are used for SIL classification of the device : SFF(Safe Failure Fraction) and PFD(Probability of Failure on Demand). In this case study, it is concluded that the flame scanner is designed to fulfill the condition of SIL 3 in the aspect of SFF and PFD.

A Study on Assembly and Evaluation of SIL optical Head for surface Recording of SIL based NFR (고체침지렌즈 기반 근접장 표면 기록을 위한 고체침지렌즈 광학 헤드의 조립 및 평가에 대한 연구)

  • Min, Cheol-Ki;Kim, Tae-Seob;Yoon, Yong-Joong;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
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    • v.4 no.1
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    • pp.19-22
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    • 2008
  • For the assembly and evaluation of solid immersion lens (SIL) optical head which is the key component of SIL based near field recording (NFR) technology, we modify the Twyman-Green interferometer. Super-hemisphere SIL optical head for the surface recording is assembled and evaluated by the modified Twyman-Green interferometer. In order to verify the optical performance of the assembled SIL optical head, we compare the measured results of the SIL optical head with the simulation ones. Finally, we show the feasibility of applying the assembled SIL optical head to near field recording system by the experiment of the dynamic gap control based on test bed.

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A Case Study of SIL Analysis for Single Station Controller in Nuclear Power Plant Based on IEC 61508 (IEC 61508에 기반한 원자력 발전소용 안전 등급 제어기의 SIL 분석에 대한 사례연구)

  • Kim, Gun Myung
    • Journal of Applied Reliability
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    • v.16 no.3
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    • pp.231-237
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    • 2016
  • Purpose: It is not easy to suggest a quantitative data related to safety analysis. The objective of this paper is to propose a method of Safety Integrity Level (SIL) analysis and to suggest a SIL analysis result for single station controller in nuclear power plant based on IEC 61508. Methods: The Failure Modes and Effects Diagnostic Analysis (FMEDA) and average probability of failure on demand (PFD) are used for SIL assessment. Results: A SIL of single station controller is evaluated 4 by a reliability analysis results and PFD. Conclusion: A SIL analysis method and result for single station controller based on IEC 61508 are proposed in this paper. It can applicable for a manufacturer data in safety-related system.

Allocation of Safety Integrity Level for Railway Platform Screen Door System considering Semi-Quantitative Risk Reduction Factor (반 정량적 리스크 저감 요소를 고려한 철도 승강장 스크린 도어시스템의 안전 무결성 수준 할당)

  • Song, Ki Tae;Lee, Sung Ill
    • Journal of the Korean Society of Safety
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    • v.31 no.4
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    • pp.156-163
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    • 2016
  • There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, the theoretical and practical study for safety integrity level is barely under way in the domestic railway industry. This research studied not only the global process of SIL allocation to guarantee safety in accordance with international standards for safety related equipment and system, but the quantitative methodology based on international standard and the semi-quantitative methodology as alternative way for SIL allocation. Specifically, the systematic SIL allocation for platform screen door system of railway is studied applying the semi-quantitative methodology in order to save much time and effort compared to quantitative method.

An Study on the Driving Prevention Technique to Prevent Driver (운전자 졸음운전예방기법에 관한 연구)

  • Kim, Ji-Yong;Kim, Chan-Min;Lee, Ji-Ho;Jeon, Seon-Jin;Cho, Jae-Ho;Park, Jin-Ho;Kim, Young-Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.04a
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    • pp.740-742
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    • 2017
  • 교통안전공단이 운전자 400명을 대상을 졸음운전 실태를 조사한 결과 최근 1주일간 10명 중 4명이 졸음운전을 경험했으며, 그 중 19%는 사고가 날 뻔한 '아차사고' 경험이 있는 것으로 나타났다고 밝혔다. 이에 따라 운전자들의 졸음운전을 예방하기 위한 시스템의 존재가 시급하다는 것을 알 수 있다. 이에 본 논문에서는 운전자의 졸음운전 사고를 예방하기 위한 운전 방지 기법을 제시한다.

A Study on the Architectural of Jae-sil in Jeonalbukdo (전라북도 재실 건축에 관한 연구)

  • Lee, Sang-Sun;Shin, Woong-Ju
    • Journal of the Korean Institute of Rural Architecture
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    • v.15 no.4
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    • pp.35-42
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    • 2013
  • The study aims to investigate general characteristics of Jae-sil from an architectural perspective by grasping location, deployment, structure, and plan composition based on existing inhabited conditions in Jeollabukdo. Results derived from the study are as follows. First, the location of Jae-sil is classified into mountainous and village types, and the two types showed a similar distribution. The village type showed the most distribution in the foot of a mountain in the rear of village, while the mountainous type is close to graveyard. The Jae-sil were mostly exposed to south, southeast, and southeast, which was not significantly different from residence. For deployment of the Jae-sil, a "二" shaped house, where main quarter and gated building are parallel located, can be common, indicating that additional attached building is less required. Second, for the platform out of structural components, coursed masonry was conducted by using natural rocks, and placed were a prop on the platform, first line on processed foot stone, and others on natural foot stone. For pillar, front line round columns, while others square columns. The binding type of the upper part of pillar is dominated by jangyeosujang and sorosujang. For wooden frame structure, 5ryangs were the most distributed, and out of these, 1goju 5ryang was the most generally used. For a roof part, it was composed with gambrel roof with single eave, and the roof was constructed by placing traditional Korean tile roof on the top. Third, for a size of Jae-sil out of plan composition, although the facade and the side of it were presented in a diverse manner, 4 facade rooms and 1.5 side rooms were the most frequently presented, and all Jae-sil were equipped with front ceremonial space. For spatial composition of Jae-sil, main floored hall is placed at the center, and each room is placed on the left and right side to secure space for ancestral rite for participants of it, and for a house with 5 rooms or more, it shows that main floored hall and rooms are weighted from side to side.

Allocation of Safety Integrity Level for Railway Platform Screen Door System based on Consequence Severity and Risk Graph (결과 심각도 및 리스크 그래프에 기반한 철도 승강장 도어시스템의 안전 무결성 수준 할당)

  • Song, Ki Tae;Lee, Sung Ill
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.164-173
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    • 2015
  • There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, application standard differs from every industry in domestic or international for application on mythology for allocation and demonstration of SIL. Application or assessment is not easy since absence on clear criteria or common definition. This research studied not only fundamental concept of SIL required to guarantee safety in accordance with international standards for safety related equipment and system, but different types of methodologies for SIL allocation. Specifically, SIL allocation for Platform Screen Door system of railway is studied applying methodology of severity of accidents and risk graph among different methodologies for SIL allocation.

Isolation and Functional Analysis of the silA Gene That Controls Sexual Development in Response to Light in Aspergillus nidulans (Aspergillus nidulans의 광 조건하 유성분화에 관여하는 silA 유전자의 분리 및 기능분석)

  • Han, Sang-Yong;Ko, Jin-A;Kim, Jong-Hak;Han, Kyu-Yong;Han, Kap-Hoon;Han, Dong-Min
    • The Korean Journal of Mycology
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    • v.36 no.2
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    • pp.189-195
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    • 2008
  • When a homothallic ascomycete Aspergillus nidulans is exposed to visible light, cleistothecial development is inhibited. The light response of development in A. nidulans implies the existence of delicate regulation process including reception and translocation of light signaling and determination of development. Previously, mutants that could develop cleistothecia even in the presence of relatively intensive visible light were isolated and several complementation groups were identified. A gene that was able to complement the silA98 mutation, which was responsible for preferred cleistothecia development under visible light, was isolated from AMA-NotI genomic library. The silA gene retained in the 4.3 kb recovered genomic library DNA has an open reading frame (ORF) consisted of 2,388 bp nucleotides, interrupted by 3 introns and consequently encoding 795 amino acids. The putative SilA carries a ${Zn_2}{Cys_6}$ binuclear cluster motif at N terminus and shows high amino acid sequence similarity to Aro80p of Saccharomyces cerevisiae. Deletion mutants of silA showed a strong induction of sexual development under visible light, indicating that SilA is involved in the negative regulation of sexual development in response to the light.