• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.644-654
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• 2024

After the Tohoku earthquake and tsunami (Japan, 2011), regulatory efforts to mitigate external hazards have increased both the safety requirements and the total capital cost of nuclear power plants (NPPs). In these circumstances, identifying not only disaster robustness but also cost-effective capacity setting of NPPs has become one of the most important tasks for the nuclear power industry. A few studies have been performed to relocate the seismic capacity of NPPs, yet the effects of multiple hazards have not been accounted for in NPP capacity optimization. The major challenges in extending this problem to the multihazard dimension are (1) the high computational costs for both multihazard risk quantification and system-level optimization and (2) the lack of capital cost databases of NPPs. To resolve these issues, this paper proposes an effective method that identifies the optimal multihazard capacity of NPPs using a multi-objective genetic algorithm and the two-stage direct quantification of fault trees using Monte Carlo simulation method, called the two-stage DQFM. Also, a capacity-based indirect capital cost measure is proposed. Such a proposed method enables NPP to achieve safety and cost-effectiveness against multi-hazard simultaneously within the computationally efficient platform. The proposed multihazard capacity optimization framework is demonstrated and tested with an earthquake-tsunami example.

• Korean Journal of Health Education and Promotion
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• v.21 no.2
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• pp.167-185
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• 2004

Objectives： The rate of adolescent smoking is important because lead to adult smoking. And early onset of smoking is associated with chronic disease in adult life. The purpose of this study is to describe the smoking status of adolescents and identify the risk factors for smoking in each school. Methods： We selected the participant schools that are located in Yang-cheon Gu, Seoul, Korea, considering the social economic status. The subjects were included 719elementary school students,1,251 middle school students and 1,513 high school students. Self-reported questionnaires were administrated between December 16 and December 24 , 2002. Students were informed in writing that the survey was voluntary. The response rate was 98.7, 81.1 and 95.4 in elementary, middle, and high school, respectively. Results： The results of this study were as follows： 1) Students who have attempted to smoke were 8.8% in elementary school, 29.3% in middle school and 35.0% in high school. 2) The current smokers were 2.0%, 7.9% and 11.5% in elementary, middle and high school, respectively. 3) In elementary school, smoking of mends and physical health were significantly predicted the attempt to smoke. Stress, smoking of mends, alcohol, and binge drinking were associated with the attempt to smoke of middle school students. In high school, the attempt to smoke was related to gender, maternal education, depression, school performance, smoking of brothers, smoking of mends, alcohol, and binge drinking. 4) Current smoking was associated with smoking of mends and binge drinking in middle school and gender, school performance, smoking of brothers, smoking of mends, alcohol, and binge drinking in high school in multiple logistic regression. Conclusion： There is a need for health education and specific strategies to help adolescents prevent from smoking. Smoking prevention programs which include risk-taking behavior such as alcohol, method of copying with stress, and supporting environment were required.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.105-116
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• 2017

In recent years, large Korean construction companies have suffered serious losses in their overseas business. Many practitioners and researchers have analyzed causes of cost overrun in these projects. However, these arguments have not been empirically verified based on acutal project cases. This study investigated cost overrun rate, contingency, allowance, predicted risk before bidding, and actual and residual risk after award in the 67 international infrastructure projects conducted by 13 large construction companies. The causes of cost overruns are derived as follows. First, they identified the possibility of cost overrun to some extent before the bidding, but did not reflect the enough risk money to bid price. In particular, this behavior was more severe in badly cost-overrun projects. Second, the causes of cost overrun were more influenced by external environmental risk than internal capability risk. However, the internal risk in badly cost-overrun projects was relatively high compared to cost-underrun projects. Third, badly cost-overrun projects failed to mitigate risk. However, cost underrun projects were affected more by low exterior risk conditions than by well mitigated risk. This study provides more informed knowledge in controlling project costs in international infrastructure projects.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1687-1692
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• 2012

Background: Few studies have examined theoretically informed constructs related to hepatitis B (HBV) testing, and comparisons across studies are challenging due to lack of uniformity in constructs assessed. The present analysis examined relationships among Health Behavior Framework factors across four Asian American groups to advance the development of theory-based interventions for HBV testing in at-risk populations. Methods: Data were collected from 2007-2010 as part of baseline surveys during four intervention trials promoting HBV testing among Vietnamese-, Hmong-, Korean- and Cambodian-Americans (n = 1,735). Health Behavior Framework constructs assessed included: awareness of HBV, knowledge of transmission routes, perceived susceptibility, perceived severity, doctor recommendation, stigma of HBV infection, and perceived efficacy of testing. Within each group we assessed associations between our intermediate outcome of knowledge of HBV transmission and other constructs, to assess the concurrent validity of our model and instruments. Results: While the absolute levels for Health Behavior Framework factors varied across groups, relationships between knowledge and other factors were generally consistent. This suggests similarities rather than differences with respect to posited drivers of HBV-related behavior. Discussion: Our findings indicate that Health Behavior Framework constructs are applicable to diverse ethnic groups and provide preliminary evidence for the construct validity of the Health Behavior Framework.

• Journal of Genetic Medicine
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• v.4 no.1
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• pp.1-5
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• 2007

Unprecedented amount of genetic information being generated from the result of Human Genome Project (HGP) and advances in genetic research is already forcing changes in the paradigm of health and disease. The ultimate goal of genetic medicine is to use genetic information and technology to develop new ways of treatment or even prevention of the disease on an individual level for 'personalized medicine'. Genetics is play ing an increasingly important role in the diagnosis, monitoring and management of common multifactorial diseases in addition to rare single-gene disorders. While wide range of genetic testing have provided benefits to patients and family, uncertainties surrounding test interpretation, the current lack of available medical options for the diseases, and risks for discrimination and social stigmatization may remain to be resolved. However an increasing number of genetic tests are becoming commercially available, including direct to consumer genetic testing, yet public is often unaw are of their clinical and social implications. The personal nature of information generated by a genetic test, its power to affect major life decisions and family members, and its potential misuse raise important ethical considerations. Therefore appropriate genetic counseling is needed for patient to be informed with the benefits, limitations and risks of genetic tests, prior to informed consent for the tests. Physician also should be familiar with the legal and ethical issues involved in genetic testing to tell patients how w ell a particular genetic risk factor relates with likelihood of disease, and be able to provide appropriate genetic counseling. Genetic counseling become a mandatory requirement as global standard for many genetic testing such as prenatal diagnosis, presymtomatic DNA diagnostic tests and cancer susceptibility gene test for familial cancer syndrome. In oder to meet the challenge of genetic medicine of 21 century in korean health care system, professional education program and certification board for medical genetics specialist including non-MD genetic counselors should be addressed by medical society and regulatory policy of national health insurance reimbursement for genetic counseling to be in place to promote the implementation of clinical genetic service including genetic counseling for proper genetic testing.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.148-157
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• 2019

Objective: To evaluate the current status of managing adverse reactions to iodinated contrast media (ICM) for computed tomography in referral hospitals in South Korea compared with hospitals in other countries. Materials and Methods: This survey investigation involved 59 Korean and 15 overseas hospitals using guideline-based questionnaires consisting of 24 items in 7 main categories related to managing adverse reactions to ICM. Results: Informed written consent with risk factor evaluation was appropriately performed in most of the Korean hospitals. There was considerable variability in assessing renal function across the hospitals; serum creatinine level was used as a reference in 76.4% of Korean hospitals. The Korean hospitals preferred a more stringent approach to determining normal renal function (p = 0.01), withholding metformin (p = 0.01), and fasting before ICM exposure (p < 0.001) compared with overseas hospitals. All the Korean hospitals had an emergency protocol and in-hospital system for adverse reactions to ICM. The Korean (87.7%) and overseas hospitals (100%) were similarly equipped with epinephrine (p = 0.332), but only 38.6% of Korean hospitals were equipped with a bronchodilator (p = 0.004). For patients with a previous hypersensitivity reaction to ICM, 62.3% of Korean hospitals pre-medicated with anti-histamine and corticosteroid according to the severity of the previous reaction, and changed the culprit ICM in 52.8%, while skin test was performed in 17%. Conclusion: In general, Korean referral hospitals were well-prepared regarding informed consent, protocol, and an in-hospital system for managing adverse reactions to ICM. Nevertheless, there was considerable variability in details and management, thus requiring standardization by reflecting current guidelines.

• Korean Journal of Biological Psychiatry
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• v.19 no.4
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• pp.153-158
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• 2012

Understanding of a clinical trial is essential in developing clinical guideline and adopting evidence based practice. In designing and executing clinical trials, following ethical requirements should be considered : social value, scientific validity, fair subject selection, informed consent, favorable risk-benefit ratio, institutional review board, and respect for human subjects. According to the stage of drug development, purpose of trials, accumulated scientific data, clinical trials for drug development are classified as phase 1, 2, 3, and 4. Phases of clinical trials can be overlapped and the judgment of entering into the next phase should be considered highly strategically. In reading, evaluating and interpreting clinical trial reports, various skills and challenges exist. Patient sample composition, trial duration, selection of endpoints, responders and non-responders, placebo effect, patient recruitment, and extrapolation to the real world are the examples of those challenges. Treatment success will come from the well balanced approach of evidence based decision making and consideration of specific single case.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.152-153
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• 2011

원자력발전소(원전) 터빈발전기에서 생산된 전력은 송전망과 발전소 운전에 필요한 기기 작동을 위해 소내로 공급되도록 설계되어 있다. 최근 신규원전의 전원 공급을 위해 가동중 원전의 송전선로 휴전 작업시 운영기술지침서의 운전제한시간을 초과한 휴전작업에 대한 안전성 문제가 대두되었다. 본 논문에서는 정상운전중인 원전의 송전선로 1개 휴전 작업중 운전중인 송전선로 상실시 리스크를 분석하여 허용기준 만족 여부를 평가하고, 리스크관리 대책을 수립하여 전력계통의 신뢰성 및 안전성 향상에 기여하고자 한다.

• Journal of the Korean Society of Visualization
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• v.4 no.1
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• pp.8-13
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• 2006

Fire simulation has been developed for decades to analyze fire cases and provide a tool to study fundamental fire dynamics and combustion. There are three way of fire simulation which are a full scale simulation, an experimental simulation and a computational simulation. In case of a full scale simulation, because a higher cost, a higher risk, more efforts are needed, a demand for it has been decreased. But recently a demand for an experimental simulation and a computational simulation has been increased. A computational simulation has several advantages; lower cost, short period, many case studies, more visual results, a quantitative result and etc. FDS(Fire Dynamics Simulator) which has been developed in BFRL(Building and Fire Research Laboratory), NIST(National Institute of Standards and Technology) is a popular world wide code for fire simulation. Lack of accurate predictions by the model could lead to erroneous conclusions with regard to fire safety. All results should be evaluated by the informed judgment of the qualified user.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.9
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• pp.1350-1358
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• 2001

During the last decade, a number of experiments and numerical analyses had been performed in conjunction with the development of simplified analytical methods to estimate the fracture behavior of cracked piping in nuclear power plant. However, the necessity of further investigation for the analytical methods was issued because of the discrepancies with the experimental data. The objective of this paper is to find out the optimum methods to evaluate the load-carrying capacities for cracked pipes. To do this, numerous analytical and finite element analyses were carried out for various pipe and crack geometries and materials. These results were synthesized for crack shapes and can be used as basic data for leak before analyses and risk informed inspections.