• Nuclear Engineering and Technology
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• 제52권8호
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• pp.1661-1668
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• 2020

A physical protection system (PPS) is used for the protection of critical facilities. This paper proposes a structure analytic hierarchy approach (SAHA) for the hierarchical evaluation of the PPS effectiveness in critical infrastructure. SAHA is based on the traditional analysis methods "estimate of adversary sequence interruption, EASI". A community algorithm is used in the building of the SAHA model. SAHA is applied to cluster the associated protection elements for the topological design of complicated PPS with graphical vertexes equivalent to protection elements.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.631-636
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• 1996

This paper presents a Reliability Centered Maintenance (RCM) framework for implementation on safety system of nuclear power plant (NPP). RCM is a systematic methodology to optimize the surveillance and maintenance tasks for critical components which provides efficiently and effectively reliability of system and safety of plant. Maintenance of the safety systems is essential for its safe and reliable operation. Reliability Centered Maintenance at NPP is the program which assure that plant system remains within original design criteria and that is not adversely affected during the plant life time. Aim of this paper is to provide the RCM framework to implement it on safety systems. RCM framework is described in four major steps.

• 시스템엔지니어링학술지
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• 제17권2호
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• pp.114-121
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• 2021

Today, it is a time when self-help efforts are being made to increase the demand for international certification by domestic and foreign railway orderers and develop excellent railway systems for railway system and railway construction projects. Since 2011, cases of obtaining international certification related to the domestic railway system/products have been collected and analyzed through literature and Internet data and based on the analysis results, evaluation results on the acquisition of international certification in Korea are presented. Through these results, the government, research institutes, and industries will be practical reference materials for international certification-related work.

• Nuclear Engineering and Technology
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• 제39권4호
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• pp.349-358
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• 2007

A single-beam gamma densitometer is utilized to measure the average void fraction in a small diameter stainless steel pipe under critical flow conditions. A typical design of a single-beam gamma densitometer is composed of a sealed gammaray source, a collimator, a scintillation detector, and a data acquisition system that includes an amplifier and a single channel analyzer. It is operated in the count mode and can be calibrated with a test pipe and various types of phantoms made of polyethylene. A good average void fraction is obtained for a small diameter pipe with various flow regimes of the core, annular, stratified, and bubbly flows. Several factors influencing the performance of the gamma densitometer are examined, including the distance between the source and the detector, the measuring time, and the ambient temperature. The void fraction is measured during an adiabatic downward two-phase critical flow in a vertical pipe. The test pipe has an inner diameter of 10.9 mm and a thickness of 3.2 mm. The average void fraction was reasonably measured for a two-phase critical flow in the presence of nitrogen gas.

• 대한안전경영과학회지
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• 제16권4호
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• pp.101-111
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• 2014

Aviation safety is increasingly important to secure the safety of the Republic of Korea Air Force (ROKAF). A critical activity for enhancing aviation safety is to analyze an accident throughly and to identify causes that can explain it reasonably. The results of such a systematic accident investigation can be effectively used for improving information displays, task procedures, and training systems as well as for reorganizing team structure and communication control system. However, the current practice of analyzing aviation accidents in ROKAF is too superficial and simple to diagnose them systematically. Additionally, the current practice does not give a full consideration to human factors that have been identified as main causes of most of the aviation accidents. With this issue in mind, this study aims to suggest a new approach to analyzing aviation accidents related to human factors.The proposed method is developed on the basis of several models and frameworks about system safety, human error, and human-system interaction. Its application to forty-two human factors-related accidents, which have occurred in ROKAF during the last ten years, showed that the proposed method could be a useful tool for analyzing aviation accidents caused by human factors.

• Wind and Structures
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• 제24권5호
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• pp.405-430
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• 2017

The aerodynamic characteristics of vehicles are critical to assess vehicle safety and passenger comfort for vehicles running on long span bridges in a windy environment. However, in previous wind-vehicle-bridge (WVB) system analysis, the aerodynamic interference between the vehicle and the bridge was seldom considered, which will result in changing aerodynamic coefficients. In this study, the aerodynamic coefficients of a high-sided truck on the ground (ground case) and a typical bridge deck (bridge deck case) are determined in a wind tunnel. The effects of existent structures including the bridge deck and bridge accessories on the high-sided vehicle's aerodynamic characteristics are investigated. A three-dimensional analytical framework of a fully coupled WVB system is then established based on the finite element method. By inputting the aerodynamic coefficients of both cases into the WVB system separately, the vehicle safety and passenger comfort are assessed, and the critical accidental wind speed for the truck on the bridge in a windy environment is derived. The differences in the bridge response between the windward case and the leeward case are also compared. The results show that the bridge deck and the accessories play a positive role in ensuring vehicle safety and improving passenger comfort, and the influence of aerodynamic interference on the response of the bridge is weak.

• 항공우주시스템공학회지
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• 제5권1호
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• pp.30-35
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• 2011

Certification flight test is very risky and there are many hazards. Because the flight test is performed with the aircraft, that is safety and flight characteristics are not proven. And the test items and conditions are critical. If there is loss of aircraft during certification flight test, the certification program, development period can be delayed. Therefore, maintaining safety of the aircraft during flight test is very important. There are not much flight test experiences in Korea. However, developed nations has long history of flight test and experiences of flight test accidents. Based on these experiences, they has developed systematic management methods for the flight test safety. In this study, I would like to introduce safety management and risk assessment of the certification flight test.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권6호
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• pp.750-759
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• 2004

원자력 발전소의 디지털 제어 시스템에 적용되는 소프트웨어는 안전성이 중요시되는 safety-critical 소프트웨어로, 충분한 수준의 안전성을 보장하기 위해서 여러 기법들이 적용되고 있다. 특히, 정형명세 기법은 개발의 초기 단계에서 소프트웨어 요구 사항들을 명확하고 완전하게 명세 하도록 유도함으로써 안전성을 크게 향상시킬 수 있는 기법으로 인정받고 있다. 본 논문에서는 원자력 발전소 디지털 제어 시스템 소프트웨어의 요구 사항 명세에 적합하도록 개발된 정형명세 기법인 NuSCR을 논의한다. 또한, 개발된 NuSCR의 적용성을 검토하기 위해, 현재 KNICS 사업단에서 개발중인 발전소보호계통 소프트웨어의 요구사항을 정형 명세 한 경험을 소개하고 있다. 또한, 원자력 도매인에 특화된 정형명세 기법인 NuSCR의 우수성도 실례를 들어 설명하고 있다.

• 한국컴퓨터정보학회논문지
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• 제23권12호
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• pp.145-151
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• 2018

While commercialization of IoT technologies in the safety management sector is being promoted in terms of industrial safety of large indoor businesses, implementing a system for risk management of small outdoor work sites with frequent site movements is not actively implemented. In this paper, we propose an efficient dynamic workload balancing strategy which combined low-power, wide-bandwidth (LPWA) communication and low-power Bluetooth (BLE) communication technologies to support customized risk management alarm systems for each individual (driver/operator/manager). This study was designed to enable long-term low-power collection and transmission of traffic information in outdoor environment, as well as to implement an integrated real-time safety management system that notifies a whole field worker who does not carry a separate smart device in advance. Performance assessments of the system, including risk alerts to drivers and workers via Bluetooth communication, the speed at which critical text messages are received, and the operation of warning/lighting lamps are all well suited to field application.

• 한국전자통신학회논문지
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• 제18권4호
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• pp.701-708
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• 2023

지방자치단체는 산업안전보건법 제4조의 2와 제4조의 3에 의하여 산업재해 예방을 위한 조치를 수행하여야 하며, 이에 본 연구는 인천광역시 사례를 통하여 중대재해 감소와 안전보건관리를 위한 IT 기반의 통합된 안전보건 정보 공유 시스템 구축의 필요성을 제시하였다. 최근 지방자치단체에서 노동안전보건 관련 조례와 기본 계획이 수립되면서 지역의 산업특성 기반의 독립된 안전보건 통합관리 체계의 필요성이 높아지고 있다. 이는 기초자치단체 및 허브기관과 협력·지원 체계 마련, 유관기관 및 단체와 협조 체계 구축에 있어 통합된 안전보건 정보공유가 필요하고, 산업재해 통계 관리, 기본 정책 이행에 대하여 지역 내 안전보건관리의 중추적 역할을 담당해야 할 것이다. 지방자치단체의 안전보건관리 통한 시스템의 지역 내 중대재해 감소와 소규모 사업장, 지방자치단체 발주 사업 등의 포괄적인 안전보건관리 시스템으로 현장 작동성이 강화되어 중대재해와 산업재해 예방의 효과성을 기대할 수 있을 것이다.