• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1394-1405
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• 2022

The importance of ensuring the inherent safety and security has been more emphasized in recent years to demonstrate the integrity of nuclear facilities under external human-induced events (e.g. aircraft crashes). This work suggests a simulation methodology to effectively evaluate the impact of a commercial aircraft engine onto a dry storage facility. A full-scale engine model was developed and verified by Riera force-time history analysis. A reinforced concrete (RC) structure of a dry storage facility was also developed and material behavior of concrete was incorporated using three constitutive models namely: Continuous Surface Cap, Winfrith, and Karagozian & Case for comparison. Strain-based erosion limits for concrete were suitably defined and the local responses were then compared and analyzed with empirical formulas according to variations in impact velocity. The proposed methodology reasonably predicted such local damage modes of RC structure from the engine missile, and the analysis results agreed well with the calculations of empirical formulas. This research is expected to be helpful in reviewing the dry storage facility design and in the probabilistic risk assessment considering diverse impact scenarios.

• 전기학회논문지
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• 제58권7호
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• pp.1380-1385
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• 2009

This paper was studied about the aging judgment method by ultraviolet rays image to happen in electric power equipment using ultraviolet rays camera. We established the aging judgment method as follows; 20% within of risk factor of insulation state of electrical facility that ultraviolet rays image does not show is "good or recognition". 30$^{\sim}$50% within of risk factor is "check", 50$^{\sim}$60% within of risk factor is "inspection" and 60% above of risk factor is "replacement". This method will be utilized for the inspection about electrical facilities.

• International Journal of Human Ecology
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• 제9권2호
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• pp.29-43
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• 2008

This study explores a model that examines how multidimensional risk factors explain mental health problems of young offenders. One hundred and ninety six students aged 13 to 15 in correctional facilities were assessed for mental health symptoms that examined the effects of multifaceted risk factors on mental health conditions. Consistent with the hypothesis of this study, secure unit students appear to have experienced various forms of risk factors and those factors have influenced mental health conditions. Results show that correctional facilities should reframe therapeutic and preventive approaches to disadvantaged students and develop integrated services and programs for rehabilitation and reintegration into society. It is recommended that those involved in treatment plans in correctional facilities consider that different treatment plans are necessary for each young offender.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.275-280
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• 2008

Recently the railway safety is very important issue in Korea because there are lots of changes like the separation of operation and facility of national rail network, the inauguration of high speed train and Daegu subway fire accident. Railway safety management system is based on risk assessment of rolling stocks, electrical system, signaling, operation & maintenance and human element. With this process, railway risk will be reduced as low as reasonably acceptable level. Through risk assessment on accident data, this study predicted the current risk level of railway electrical system and presented the proper safety ensuring measures.

• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1464-1478
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• 2021

Selective Production of Exotic Species is an innovative plant for advanced nuclear physic studies. A radioactive beam, generated by using an UCx target-ion source system, is ionized, selected and accelerated for experimental objects. Very high vacuum conditions and appropriate safety systems to storage exhaust gases are required to avoid radiological risk for operators and people. In this paper, Failure Mode, Effects, and Criticality Analysis of a preliminary design of high activity gas recovery system is performed by using a modified Fuzzy Risk Priority Number to rank the most critical components in terms of failures and human errors. Comparisons between fuzzy approach and classic application allow to show that Fuzzy Risk Priority Number is able to enhance the focus of risk assessments and to improve the safety of complex and innovative systems such as those under consideration.

• 방사성폐기물학회지
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• 제15권2호
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• pp.161-172
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• 2017

중 저준위 방사성폐기물 처분시설의 운영 중 사고로 인한 방사선적 영향을 평가하기 위해서는 운영 중 발생 가능한 사고에 대한 타당성이 입증되어야 한다. 본 논문에서는 처분시설의 운영 중 사고분석 체계를 처분시설의 구성요소에 대한 안전기능분석, 잠재위험요소분석, 위험도분석, 그리고 향후 조치대안으로 사고평가체계를 개선하였다. 이를 위하여 위험도분석에 필요한 설계대안과 관리대안을 추가하여 설계-운영-평가가 연계되도록 하였다. 또한 운영 중 사고의 발생확률과 평가결과의 심각성에 따라 운영중 사고에 대한 분류기준을 제안하여 처분시설 운영 중 대표 사고시나리오에 대한 정당성을 확보하였다. 본 논문의 개선된 평가체계를 우리나라의 2단계 중 저준위 방사성폐기물 표층처분시설에 대한 처분시설 운영 중 사고분석의 사례에 대해 적용하였다.

• 한국학교ㆍ지역보건교육학회지
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• 제12권1호
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• pp.71-89
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• 2011

Objectives: The purpose of this study is to identify risk behavior related to the school accident between male and female elementary school students. Methods: 838 School accident data provided by Seoul School Safety Council were analyzed by gender. Based on the results above, survey questionnaires on characteristics of school accident were developed. Self-reported data were collected from a sample population of 433 students in grade 5 to 6 students attending 4 elementary schools in Seoul. Results: The students who answered they experienced the accident in school for the past 1 year, accounts 60.5% of male and 39.5% of females students, which has statistically significant difference. The male's cases happened most around corridor/door, while female's cases happened most in the playground/gymnasium. As for the accident risk behavior, male students had the risk behavior by using the personal belongings/toys, while the female students had much risk behavior related to physical facility/playground. When classifying the characteristics of risk behaviors according to the accident causes, male students showed higher score in the accident risk behaviors related to play/fight than in those of the female students(p<0.05). Conclusions: Health care providers should develop school safety programs by characteristics of risk behavior between male and female elementary school students.

• 한국산업융합학회 논문집
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• 제24권5호
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• pp.609-615
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• 2021

Chemical accidents can happen anywhere in the world. To prevent chemical accidents, Korea introduced the Chemicals Control Act. However, Small and medium-sized businesses do not meet these regulations. Accordingly, the Ministry of Environment is providing a chemical safety management support project for Small and medium-sized businesses. However, there are many small and medium-sized businesses, and businesses that need support need priority. In this study, the risk of the plants was classified into hig h, medium, and low risk based on four methods. As a result, out of 90 plants subject to the study, high risk was 30% and medium risk was 70%. The industries with the high risk were chemical products manufacturing and paint manufacturing. The plating and printing industries showed relatively medium risk. This risk classification has the advantage that it can obtain intuitive and quick results. These studies can be used as basic data for chemical safety management of local governments and Ministry of Environment.

• 한국조경학회지
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• 제18권4호
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• pp.127-140
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• 1991

The Primary purpose of this study is to investigate factors and variables which have significant effects on user satisfaction with recreational facilities in Taejong-Dae recreational complex, thereby establishing indices of planning and development of urban parks and open space. To test the causal models of this research, the date were gathered by self-administered questionnaires from 967 households in Pusan City which were selected by the multi-stage probability sampling methood. The analysis of the multi-stage primarily consists of two phase : The first analysis dealt exploratory factor analysis which identified major factors involved in satisfaction with recreational activities and facilities in Taejong-Dae recreational complex and the second analysis tested the fit of the causal models of this research by employing LISREL methodology. There are three advantages of using LISREL over other multivariate analysis methods : First, measurement error is allowed and calculated in LISREL, otherwise there is a risk of seriously misleading estimates of coefficients ; Second, LISREL deals with latent variables or unmeasured variables ; Third, it enables to test causal relations among variables. The factors analysis identified that five factors are involved in satisfaction with recreational facilities. The five factors of satisfaction with recreational facilities are space for repose and relaxation, active recreation facilities such as pool and zoo, physical exercise facility, convenience and maintenance facility, and linear facility, and linear facility for walking. The second phase analysis tested the fit of the causal models for satisfaction with recreational facilities to the data and identified statistically significant causal linkage among overall satisfaction with Taejong-Dae recreational complex, other endogenous factors and exogenous variables. Overall fits of both causal models were very good. Among endogenous factors, facility for repose and relaxation. linear facility for walking, active recreation facility, facility for convenience and maintenance were identified as having significant effects on overall satisfaction. Exogenous variables which have significant effects on endogenous variables wer also identified. These significant relationships indicate important factors and variables that should be considered in planning and development of the recreational complex. On the basis of these significant causal relationships, implications for planning and the delovepment of Taejong-Dae recreational complex were suggested.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.3879-3891
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• 2021

A heat pipe residual heat removal system is proposed to be incorporated into the reactor driven subcritical (RDS) facility, which has been proposed by MIT Nuclear Reactor Laboratory for testing and demonstrating the Fluoride-salt-cooled High-temperature Reactor (FHR). It aims to reduce the risk of the system operation after the shutdown of the facility. One of the main components of the system is an air-cooled heat pipe heat exchanger. The alkali-metal high-temperature heat pipe was designed to meet the operation temperature and residual heat removal requirement of the facility. The heat pipe model developed in the previous work was adopted to simulate the designed heat pipe and assess the heat transport capability. 3D numerical simulation of the subcritical facility active zone was performed by the commercial CFD software STAR CCM + to investigate the operation characteristics of this proposed system. The thermal resistance network of the heat pipe was built and incorporated into the CFD model. The nominal condition, partial loss of air flow accident and partial heat pipe failure accident were simulated and analyzed. The results show that the residual heat removal system can provide sufficient cooling of the subcritical facility with a remarkable safety margin. The heat pipe can work under the recommended operation temperature range and the heat flux is below all thermal limits. The facility peak temperature is also lower than the safety limits.