• 한국구조물진단유지관리공학회 논문집
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• 제14권6호
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• pp.246-253
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• 2010

시설물의 안전관리에 관한 특별법이 1995년 제정된 이후 정밀점검 및 정밀안전진단을 실시하여 국가의 주요시설물의 안전 확보에 기여해 왔다. 그러나 관리주체의 안전등급 판정 개입, 안전진단전문기관의 저가수주, 진단기술력 부족 등으로 점검 진단의 실효성에 관한 의문이 꾸준히 제기되어 왔다. 이에 평가제도가 도입되어 부실 점검 진단 방지로서 역할과 기능을 하고 있지만, 앞으로 부실 점검 진단비율을 더 이상 낮아지기 힘들다는 의견이 대두되고 있다. 따라서 현행 평가제도와 부실 점검 진단비율에 대한 현황 분석을 실시하고, 부실 점검 진단으로 인한 국가적 손실비용을 추정함으로서 현행 평가제도 개선의 필요성과 당위성을 제시하고자 하였다.

• Structural Engineering and Mechanics
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• 제56권4호
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• pp.549-567
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• 2015

A first-order moment method (FORM) reliability analysis is commonly used for structural stability analysis. It requires the values and partial derivatives of the performance to function with respect to the random variables for the design. These calculations can be cumbersome when the performance functions are implicit. A Gaussian process (GP)-based response surface is adopted in this study to approximate the limit state function. By using a trained GP model, a large number of values and partial derivatives of the performance functions can be obtained for conventional reliability analysis with a FORM, thereby reducing the number of stability analysis calculations. This dynamic renewed knowledge source can provide great assistance in improving the predictive capacity of GP during the iterative process, particularly from the view of machine learning. An iterative algorithm is therefore proposed to improve the precision of GP approximation around the design point by constantly adding new design points to the initial training set. Examples are provided to illustrate the GP-based response surface for both structural and non-structural reliability analyses. The results show that the proposed approach is applicable to structural reliability analyses that involve implicit performance functions and structural response evaluations that entail time-consuming finite element analyses.

• 해양환경안전학회지
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• 제15권2호
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• pp.119-125
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• 2009

최근 민간투자에 의한 사회기반시설 확충, 육상 도로망의 직선화 및 최적화를 위해 항만 및 주요 항로를 횡단하는 해상교량 건설이 활발히 추진되고 있다. 이러한 해상교량 건설에 있어 해상이용자의 통항 안전, 항만 운영의 효율화 및 장기 개발 등에 미치는 영향을 충분히 고려하지 않고 경제적인 측면만을 부각하여 건설되고 있다. 이로 인해 해상교량의 위치 및 규모 결정시 해상교통안전 확보를 요구하는 해상이용자와 해상교량 건설주체와 지속적인 갈등이 반복되고 있는 실정이다. 이러한 문제들의 근본적 원인은 항만의 개발 운영 및 해상교통안전 관점에서 제시된 해상교량 건설시에 필요한 교량규모 및 통항 예상 대상 선박 등에 대한 설계기준 및 절차 통이 없기 때문이다. 이에 본 연구에서는 항만별 해상교량 건설현황을 조사 분석을 통해 국내 해상교량 건설에 따른 절차상의 문제점을 우선 고찰하여 개선 방안을 제시하고자 한다.

• 한국안전학회지
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• 제33권4호
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• pp.8-14
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• 2018

In the industrial chemical process involving combustible materials, reliable safety data are required for design prevention, protection and mitigation measures. The accurate combustion properties are necessary to safely treatment, transportation and handling of flammable substances. The combustion parameters necessary for process safety are lower flash point, upper flash point, fire point, lower explosion limit(LEL), upper explosion limit(UEL)and autoignition temperature(AIT) etc.. However, the combustion properties suggested in the Material Safety Data Sheet (MSDS) are presented differently according to the literatures. In the chemical industries, tetralin which is widely used as a raw material of intermediate products, coating substances and rubber chemicals was selected. For safe handling of tetralin, the lower and flash point, the fire point, and the AIT were measured. The LEL and UEL of tetralin were calculated using the lower and upper flash point obtained in the experiment. The flash points of tetralin by using the Setaflash and Pensky-Martens closed-cup testers measured $70^{\circ}C$ and $76^{\circ}C$, respectively. The flash points of tetralin using the Tag and Cleveland open cup testers are measured $78^{\circ}C$ and $81^{\circ}C$, respectively. The AIT of the measured tetralin by the ASTM E659 apparatus was measured at $380^{\circ}C$. The LEL and UEL of tetralin measured by Setaflash closed-cup tester at $70^{\circ}C$ and $109^{\circ}C$ were calculated to be 1.02 vol% and 5.03 vol%, respectively. In this study, it was possible to predict the LEL and the UEL by using the lower and upper flash point of tetralin measured by Setasflash closed-cup tester. A new prediction method for the ignition delay time by the ignition temperature has been developed. It is possible to predict the ignition delay time at different ignition temperatures by the proposed model.

• 한국안전학회지
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• 제28권3호
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• pp.44-50
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• 2013

Process gas piping is one of the most basic components frequently used in the refinery and petrochemical plants. Many kinds of by-product gas have been used as fuel in the process plants. In some plants, natural gas is additionally introduced and mixed with the byproduct gas for upgrading the fuel. In this case, safety or design margin of the changed piping system of the plant should be re-evaluated based on a proper design code such as ASME or API codes since internal pressure, temperature and gas compositions are different from the original plant design conditions. In this study, series of piping stress analysis were conducted for a process piping used for transporting the mixed gas of the by-product gas and the natural gas from a mixing drum to a knock-out drum in a refinery plant. The analysed piping section had been actually installed in a domestic industry and needed safety audit since the design condition was changed. Pipe locations of the maximum system stress and displacement were determined, which can be candidate inspection and safety monitoring points during the upcoming operation period. For studying the effects of outside air temperature to safety the additional stress analysis were conducted for various temperatures in $0{\sim}30^{\circ}C$. Effects of the friction coefficient between the pipe and support were also investigated showing a proper choice if the friction coefficient is important. The maximum system stresses were occurred mainly at elbow, tee and support locations, which shows the thermal load contributes considerably to the system stress rather than the internal pressure or the gravity loads.

• 한국산업보건학회지
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• 제24권3호
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• pp.272-280
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• 2014

Objectives: The purpose of this study was to evaluate the characteristics of worker exposure to hazardous chemical substances and propose the direction of work environment management for protecting worker's health in the semiconductor assembly process. Methods: Four assembly lines at two semiconductor manufacturing companies were selected for this study. We investigated the types of chemicals that were used and generated during the assembly process, and evaluated the workers' exposure levels to hazardous chemicals such as benzene and formaldehyde and the current work environment management in the semiconductor assembly process. Results: Most of the chemicals used at the assembly process are complex mixtures with high molecular weight such as adhesives and epoxy molding compounds(EMCs). These complex mixtures are stable when they are used at room temperature. However workers can be exposed to volatile organic compounds(VOCs) such as benzene and formaldehyde when they are used at high temperature over $100^{\circ}C$. The concentration levels of benzene and formaldehyde in chip molding process were higher than other processes. The reason was that by-products were generated during the mold process due to thermal decomposition of EMC and machine cleaner at the process temperature($180^{\circ}C$). Conclusions: Most of the employees working at semiconductor assembly process are exposed directly or indirectly to various chemicals. Although the concentration levels are very lower than occupational exposure limits, workers can be exposed to carcinogens such as benzene and formaldehyde. Therefore, workers employed in the semiconductor assembly process should be informed of these exposure characteristics.

• 한국철도학회논문집
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• 제12권3호
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• pp.382-387
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• 2009

일반적으로 고객의 요구사항을 시스템이나 서비스로 구현하는 과정에서 구현된 시스템이나 서비스들이 요구사항을 만족하여 개발 되었는지를 검증하게 된다. 그러나 철도분야의 안전체계나 안전기준을 개발하는 국가연구개발프로젝트의 경우 일반적인 검증 프로세스를 활용하여 이러한 성과물을 검증하는데 많은 한계가 있다. 본 연구에서는 국가연구개발프로젝트를 통해서 산출되는 안전체계, 안전기준, 프로세스 등의 성과물에 대한 체계적이고 효과적인 검증 프로세스를 제시하였으며, 성과물 검증 프로세스의 결과물을 전산 관리할 수 있는 방안 또한 제시하였다.

• 한국재난정보학회 논문집
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• 제20권2호
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• pp.398-410
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• 2024

연구목적:정부와 지방자치단체에서 실효성 있는 '안전관리계획'수립을 위한 전반적인 '재난관리 수행과정'(가칭)의 발전방향을 제시하는데 있다. 연구방법: 이를 위해 '안전관리계획'에 대한 선행연구를 검토하여 공통적인 문제점들을 도출하였고, 이러한 문제점들을 해결할 수 있는 '재난관리 수행과정' (가칭)을 군(軍)의 '작전수행과정'을 접목하여 발전방향을 제시하였다. 연구결과: 본 연구자가 제시한 '재난관리 수행과정'(가칭)을 통해 선행연구의 공통적인 문제점들을 보완할 수 있다. 결론: '재난관리 수행과정'(가칭)을 통해서 최종적으로는 '국가와 지방자치단체의 기본적 임무임을 확인하고, 국민이 재난으로부터 안전한 사회에서 생활할 수 있도록 한다'는 정부의 재난관리 기본이념을 달성할 수 있다.

• 정보통신설비학회논문지
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• 제9권3호
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• pp.102-106
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• 2010

Recently process industries from oil and gas procedures and mining companies to manufactures of chemicals, foods, and beverages has been exploring the USN (Ubiquitous Sensor Networks) technology to improve safety of production processes. However, to apply the USN technology in the large-scale plant industry, reliability and security issues are not fully addressed yet, and the absence of the industrial sensor networking standard causes a compatibility problem with legacy equipment and systems. Although this situation, process industry such as energy plants are looking for the secure wireless plant solution to provide detailed, accurate safety monitoring from previously hard-reach, unaccordable area. In this paper, SPSF (Smart Plant Safety Framework based on Reliable-Secure USN) is suggested to fulfill the requirements of high-risk industrial environments for highly secure, reliable data collection and plant monitoring that is resistant to interference. The SPSF consists of three main layers: 1) Smart Safety Sensing Layer, 2) Smart Safety Network Layers, 3) Plant Network System Layer.

• 산업경영시스템학회지
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• 제22권53호
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• pp.79-88
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• 1999

This paper presents an integral model for product safety and product liability resulting from a defective product. The essence of the paper is the process of supply of manufacturing products which satisfy the product liability and the product safety in terms of consumers expectation levels. The main criteria of the product safety is the hazard level which involves in the severity and frequency. The proposed model shows the process to supply the manufactured products under the conditions that they are suitable in comparison of hazard level and safety level established by each company. If the product do not meet the safety level, this paper proposes that four different types of PL and PS countermeasures for the risk types are forward, respectively.