• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.579-586
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• 2022

Modular building is a fast-growing construction method, mainly due to its ability to drastically reduce the amount of time it takes to construct a building and produce higher-quality buildings at a more consistent rate. However, while modular construction is relatively safer than traditional construction methods, workers are still exposed to hazards that lead to injuries and fatalities, and these hazards could be controlled using emerging smart technologies. Currently, limited information is available at the intersection of modular construction, safety risk, and smart safety technologies. This paper aims to investigate what aspects of modular construction are most dangerous for its workers, highlight specific risks in its processes, and propose ways to utilize smart technologies to mitigate these safety risks. Findings from the archival analysis of accident reports in Occupational Safety and Health Administration (OSHA) Fatality and Catastrophe Investigation Summaries indicate that 114 significant injuries were reported between 2002 and 2021, of which 67 were fatalities. About 72% of fatalities occurred during the installation phase, while 57% were caused by crushing and 85% of crash-related incidents were caused by jack failure/slippage. IoT-enabled wearable sensing devices, computer vision, smart safety harness, and Augment and Virtual Reality were identified as potential solutions for mitigating identified safety risks. The present study contributes to knowledge by identifying important safety trends, critical safety risk factors and proposing practical emerging methods for controlling these risks.

• Computers and Concrete
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• 제14권2호
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• pp.127-143
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• 2014

LOCA (Loss Of Coolant Accident) is one of the most important utmost accidents for Prestressed Concrete Containment Vessel (PCCV) due to its coupled effect of high temperature and inner pressure. In this paper, heat conduction analysis is used to obtain the LOCA temperature distribution of PCCV. Then the elastic internal force of PCCV under LOCA temperature is analyzed by using both simplified theoretical method and FEM (finite element methods) method. Considering the coupled effect of LOCA temperature, a nonlinear elasto-plasitic analysis is conducted for PCCV under utmost internal pressure considering three failure criteria. Results show that the LOCA temperature distribution is strongly nonlinear along the shell thickness at the early time; the moment result of simplified analysis is well coincident with the one of numerical analysis at weak constraint area; while in the strong constrained area, the value of moments and membrane forces fluctuate dramatically; the simplified and numerical analysis both show that the maximum moment occurs at 6hrs after LOCA.; the strain of PCCV under LOCA temperature is larger than the one of no temperature under elasto-plastic analysis; the LOCA temperature of 6hrs has the greatest influence on the ultimate bearing capacity with 8.43% decrease for failure criteria 1 and 2.65% decrease for failure criteria 3.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.356-367
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• 2018

A series of tests dedicated to station blackout (SBO) accident scenarios have been recently performed at the $Prim{\ddot{a}}rkreislauf-Versuchsanlage$ (primary coolant loop test facility; PKL) facility in the framework of the OECD/NEA PKL-3 project. These investigations address current safety issues related to beyond design basis accident transients with significant core heat up. This work presents a detailed analysis using the best estimate thermal-hydraulic code TRACE (v5.0 Patch4) of different SBO scenarios conducted at the PKL facility; failures of high- and low-pressure safety injection systems together with steam generator (SG) feedwater supply are considered, thus calling for adequate accident management actions and timely implementation of alternative emergency cooling procedures to prevent core meltdown. The presented analysis evaluates the capability of the applied TRACE model of the PKL facility to correctly capture the sequences of events in the different SBO scenarios, namely the SBO tests H2.1, H2.2 run 1 and H2.2 run 2, including symmetric or asymmetric secondary side depressurization, primary side depressurization, accumulator (ACC) injection in the cold legs and secondary side feeding with mobile pump and/or primary side emergency core coolant injection from the fuel pool cooling pump. This study is focused specifically on the prediction of the core exit temperature, which drives the execution of the most relevant accident management actions. This work presents, in particular, the key improvements made to the TRACE model that helped to improve the code predictions, including the modeling of dynamical heat losses, the nodalization of SGs' heat exchanger tubes and the ACCs. Another relevant aspect of this work is to evaluate how well the model simulations of the three different scenarios qualitatively and quantitatively capture the trends and results exhibited by the actual experiments. For instance, how the number of SGs considered for secondary side depressurization affects the heat transfer from primary side; how the discharge capacity of the pressurizer relief valve affects the dynamics of the transient; how ACC initial pressure and nitrogen release affect the grace time between ACC injection and subsequent core heat up; and how well the alternative feeding modes of the secondary and/or primary side with mobile injection pumps affect core quenching and ensure stable long-term core cooling under controlled boiling conditions.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.1-13
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• 2020

At present, the Department of Energy (DOE) in Unite State are directing the efforts of developing accident tolerant fuel (ATF) technology. As the first barrier of nuclear fuel system, the material selection of fuel rod cladding for ATFs is a basic but very significant issue for the development of this concept. The advanced cladding is attractive for providing much stronger oxidation resistance and better in-pile behavior under sever accident conditions (such as SBO, LOCA) for giving more coping time and, of course, at least an equivalent performance under normal condition. In recent years, many researches on in-plie or out-pile physical properties of some suggested cladding materials have been conducted to solve this material selection problem. Base on published literatures, this paper introduced relevant research backgrounds, objectives, research institutions and their progresses on several main potential claddings include triplex SiC, FeCrAl and MAX phase material Ti3SiC2. The physical properties of these claddings for their application in ATF area are also reviewed in thermohydraulic and mechanical view for better understanding and simulating the behaviors of these new claddings. While most of important data are available from publications, there are still many relevant properties are lacking for the evaluations.

• Nuclear Engineering and Technology
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• 제43권6호
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• pp.509-522
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• 2011

FRAPCON-3.4a and FRAPTRAN 1.4 are the most recent versions of the U.S. Nuclear Regulatory Commission (NRC) steady-state and transient fuel performance codes, respectively. These codes have been assessed against separate effects data and integral assessment data and have been determined to provide a best estimate calculation of fuel performance. Recent updates included in FRAPCON-3.4a include updated material properties models, models for new fuel and cladding types, cladding finite element analysis capability, and capability to perform uncertainty analyses and calculate upper tolerance limits for important outputs. Recent updates included in FRAPTRAN 1.4 include: material properties models that are consistent with FRAPCON-3.4a, cladding failure models that are applicable for loss-of coolant-accident and reactivity initiated accident modeling, and updated heat transfer models. This paper briefly describes these code updates and data assessments, highlighting the particularly important improvements and data assessments. This paper also discusses areas of improvements that will be addressed in upcoming code versions.

• 대한치과기공학회지
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• 제38권4호
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• pp.343-352
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• 2016

Purpose: The intention of the study is to reveal the factors that influence the safety-behavior and safety-accident of the students of dental laboratory science. We intend to use the study as a basic data of searching effective ways to heighten the safety-behavior of clinical training and to prevent safety-accident. Methods: The survey was conducted on dental technology students. The collected data was analyzed by the statistical program SPSS 21.0. The results were analyzed by reliability, frequency, t-test, correlation, multiple regression. To test for significance on each item, p<0.05 has been decided as a standard. Results: The results of the study showed that the safety of the students was influenced by the school year, the leader of clinical training, clinical training environment and the experience of safety education. The safety-accident turned out to be influenced by the school year of the student and the safety behavior. Conclusion: Active leader of clinical training, clinical training environment that enables the safety-behavior, and the offering of the systematic safety education were the most important factors to heighten the safety behavior of the students and prevent the safety-accident. These factors were expected to not only induce the safety-behavior but also prevent the safety-accident as well.

• 대한안전경영과학회지
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• 제20권3호
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• pp.21-26
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• 2018

This paper describes result of a study on safety against a fire of charging cable for mobile phone for vehicle. Combustion on the USB cable in the car was happened while driving. Gas coming from the burning USB cable could be a reason which can make a secondary car accident since the driver also can be embarrassed while driving. In order to prevent a secondary car accident connected on the road, to research a reason why USB cable can emit gas and be burned in charging. We did simulation test with abnormal fault condition for the electronic component on the board in the USB cable. So we get the result from abnormal fault condition simulation test, for instance, shorted test for output terminal of 8 pin switch, shorted test for chip resistor after thermal aging in the condition $25^{\circ}C$, 93 % RH during 48 hours. To analysis the result of all test, Combustion on the USB cable was not the 8 pin but other electrical component such as a chip resistor. Therefore we guess that the reason for USB cable combustion in charging in a car was not 8 pin and a LED but another defective component.

• 대한의생명과학회지
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• 제23권3호
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• pp.155-160
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• 2017

Biomedical laboratory is full of risks. Risk could be biological, chemical, radioactive, mechanical, physical, fire and electrical. All possible risks need to be identified, evaluated and controlled. A risk management system must be in place to prevent accident or loss of lives and to improve overall workplace safety and productivity. Safety in laboratory is a combination of appropriate risk management system, engineering controls and technical facilities, administrative controls and safety procedures and practices. Laboratory safety culture must be developed so that exposure to hazards for laboratory personnel, community and environment will be minimized or eliminated. In this review, importance of safety in a biomedical laboratory and risk management will be discussed.

• 대한안전경영과학회지
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• 제9권6호
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• pp.19-29
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• 2007

According to industrial disaster statistics by the Ministry of Labor in 2006, out of 11,688,797 people working at 1,292,696 business places that apply Industrial Disaster Indemnity Act, 89,910 workers were involved in an accident that more than 4 days of medical treatment requires. Among this figure 2,453 people lost their precious lives. "89,910 industrial disaster victims per annum" is showing the safety level of our industrial situation. To prevent such industrial disaster, the most typical and distinctive method is Accident-free Campaign. At the beginning, the movement arose with devotion through out the entire industry. But, the heartbreaking fact is that the fever is getting cool gown as times goes by. Therefore, opportunity for revitalization of this movement is required. The movement should be practically supporting principle of respect for human life and dignity. And it should be established with analysis on industrial disaster and systematize Accident-free Campaign totally in connected research.

• 한국가스학회지
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• 제24권4호
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• pp.1-9
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• 2020

기업부설연구소나 학교 내의 연구실에서 빈번하게 발생하는 안전사고를 예방하기 위해 2015년 연구실 안전환경 조성에 관한 법률이 제정되었다. 하지만, 연구실 안전을 위한 여러 제도가 동시에 운영되고 있어 근본적이고 총괄적인 안전관리 대책이 필요한 시점이다. 본 연구에서는 안전관리 검사체계 측면의 실효적인 개선방법을 제안하고자 먼저, 국내 연구실 안전관리 규정을 조사·비교하였으며, 규정 간 검사의 차이로 인해 발생하는 문제점을 도출하였다. 또한, 각 규정의 구체적인 검사항목을 시설측면과 관리측면으로 구분하여 비교하고, 그 개선 방법을 제안하였다. 그 결과 동일한 연구실임에도 불구하고 시기에 따라 다른 법령에 따른 검사로 관리되고 있었으며, 검사항목에서도 화학시설의 구조 및 성능에 관한 안전기준을 중점과 시약 및 폐액의 보관 상태, 독성물질의 관리상태 등의 관리기준 중점으로 차이가 있었다. 본 연구에서 고찰한 문제점과 제안은 연구실 사고예방을 위한 근본적인 안전관리 체계로의 발전에 도움이 될 수 있을 것으로 기대된다.