• Corrosion Science and Technology
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• 제8권3호
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• pp.119-125
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• 2009

Corrosion assessment has a number of uses but the use considered here is as a precursor to Risk-Based Inspection (RBI) planning. Systematic methods consisting of technical modules of RBI program were used to assess the effect of specific corrosion mechanism on the probability of failure in equipments of petrochemical plants. Especially in part of the damage and corrosion assessment, screening step involved evaluating the combinations of process conditions and construction materials for each equipment item in order to determine which damage mechanisms are potentially active. For general internal corrosion, either API 510 or API 570 was applied as the damage rate in the calculation to determine the remaining life and inspection frequency. In some cases, a measured rate of corrosion may not be available. The technical modules of RBI program employ default values for corrosion, typically derived from published data or from experience with similar processes, for use until inspection results are available. This paper describes the case study of corrosion and damage assessment by using RBI methodology in petrochemical plant. Specifically, this paper reports the methodology and the results of its application to the petrochemical units using the $KGS-RBI^{TM}$ program, developed by the Korea Gas Safety Corporation to suit Korean situation in conformity with API 581 Codes.

• Safety and Health at Work
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• 제10권4호
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• pp.409-419
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• 2019

Although the rare earth elements (REEs) recycling industry is expected to increase worldwide in hightech industry, regulations for worker safety have yet to be established. This study was conducted to understand the potential hazard/risk of REE recycling and to support the establishment of regulations or standards. We review the extensive literature on the toxicology, occupational safety, and health issues, and epidemiological surveys related to the REEs, and propose suitable management measures. REE recycling has four key steps such as collection, dismantling, separation, and processing. In these processes, hazardous substances, such as REEs-containing dust, metals, and chemicals, were used or occurred, including the risk of ignition and explosion, and the workers can be easily exposed to them. In addition, skin irritation and toxicities for respiratory, nervous, and cardiovascular systems with the liver toxicity were reported; however, more supplementary data are needed, owing to incompleteness. Therefore, monitoring systems concerning health, environmental impacts, and safety need to be established, based on additional research studies. It is also necessary to develop innovative and environment-friendly recycling technologies, analytical methods, and biomarkers with government support. Through these efforts, the occupational safety and health status will be improved, along with the establishment of advanced REE recycling industry.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.426-433
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• 2017

This paper describes the development process, the innovative techniques used and insights gained from the latest integrated, full scope, multistate Level 2 PSA analysis conducted at the Leibstadt Nuclear Power Plant (KKL), Switzerland. KKL is a modern single-unit General Electric Boiling Water Reactor (BWR/6) with Mark III Containment, and a power output of $3600MW_{th}/1200MW_e$, the highest among the five operating reactors in Switzerland. A Level 2 Probabilistic Safety Assessment (PSA) analyses accident phenomena in nuclear power plants, identifies ways in which radioactive releases from plants can occur and estimates release pathways, magnitude and frequency. This paper attempts to give an overview of the advanced modeling techniques that have been developed and implemented for the recent KKL Level 2 PSA update, with the aim of systematizing the analysis and modeling processes, as well as complying with the relatively prescriptive Swiss requirements for PSA. The analysis provides significant insights into the absolute and relative importances of risk contributors and accident prevention and mitigation measures. Thanks to several newly developed techniques and an integrated approach, the KKL Level 2 PSA report exhibits a high degree of reviewability and maintainability, and transparently highlights the most important risk contributors to Large Early Release Frequency (LERF) with respect to initiating events, components, operator actions or seismic component failure probabilities (fragilities).

• 응용통계연구
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• 제24권4호
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• pp.575-586
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• 2011

본 연구는 보험산업에서 관심을 갖는 파산확률의 근사적 추이를 살펴보기 위하여 크레임의 분포가 정규변동성 성질을 갖는 사례를 통하여 파산가능성의 추이를 살펴보고, 정확한 파산확률 유도에 결정적인 역할을 하는 계수를 추정하는 실증연구에 초점을 둔다. 추정된 결정계수와 보험위험 확률모형의 안전지수와의 연관성을 분석하여 파산확률의 추이를 진단하는 방법도 함께 진행된다.

• International Journal of Aeronautical and Space Sciences
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• 제16권3호
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• pp.451-462
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• 2015

Safety is the first priority in civil aviation, and so the International Civil Aviation Organization (ICAO) has introduced and mandated the use of Safety Management Systems (SMS) by airlines, airports, air traffic services, aircraft maintenance organizations, and training organizations. The aircraft manufacturing industry is the last for which ICAO has mandated the implementation of SMS. Since SMS is a somewhat newer approach for most manufacturers in the aviation industry, they hardly believe in the value of implementing SMS. The management of safety risk characteristics that occur during early aircraft development stages and the systematic linkage that the safety risk has to do with an aircraft in service could have a significant influence on the safe operation and life cycle of the aircraft. This paper conducts a case analysis of the McDonnell Douglas MD-11 accident/incident to identify the root causes and safety risk levels, and also verified why aircraft manufacturing industry should begin to adopt SMS in order to prevent aircraft accident.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.347-349
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• 2014

Model verification and validation (V&V) is a current research topic to build computational models with high predictive capability by addressing the general concepts, processes and statistical techniques. The hypothesis test for validity check is one of the model validation techniques and gives a guideline to evaluate the validity of a computational model when limited experimental data only exist due to restricted test resources (e.g., time and budget). The hypothesis test for validity check mainly employ Type I error, the risk of rejecting the valid computational model, for the validity evaluation since quantification of Type II error is not feasible for model validation. However, Type II error, the risk of accepting invalid computational model, should be importantly considered for an engineered products having high risk on predicted results. This paper proposes a technique named as the response-adaptive experimental design to reduce Type II error by adaptively designing experimental conditions for the validation experiment. A tire tread block problem and a numerical example are employed to show the effectiveness of the response-adaptive experimental design for the validity evaluation.

• 기본간호학회지
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• 제17권2호
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• pp.249-258
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• 2010

Purpose: To develop an e-learning blood-borne infection control program and to evaluate the effects of the program on risk perception, knowledge, preventive health behaviors related to blood-borne infections, and satisfaction with the program by nursing student. Methods: The program was developed through the processes of analysis, design, development, implementation, and evaluation. The pre-experimental research design involved a one group pretest-posttest design. The setting was two universities located in Daejeon, Korea. Results: Using the program that was designed and developed, results for the total score of risk perception, knowledge, and preventive health behaviors in the post-test application were significantly higher than in the pre-test application (p<.05). Relevance and usefulness of the information received the highest ratings, while the system's design were demonstrated to have the lowest ratings. Those areas requiring correction were modified accordingly. Conclusions: Application of an e-learning blood-borne infection control program is effective, and can be expanded to other student nurses who also have a high risk of blood-borne infections.

• Industrial Engineering and Management Systems
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• 제14권4호
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• pp.372-378
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• 2015

In labor-intensive enterprise, such as garment factory, assembly line is widely used as a manufacturing process for reducing costs and production time. However, for the sake of the various working capacity of worker, idle or delay may happen and influence the rear processes. If these unforeseeable delay happened continuously, it may influence the whole manufacturing process and a model, which is called limited-cycle model with multiple periods (LCMwMP), is assumed to evaluate the influence risk. In order to minimize the risk, the assignment of the workers is focused on. In this paper, we deal with an assembly line as LCMwMP model when two kinds of workers exist, whose efficiency is assumed to two different groups. We consider an optimization problem for finding an assignment of workers to the line that minimizes total expected risk, which is exchanged to expected cost by reset model of LCMwMP. First, reset model as a simple model of LCMwMP is introduced. Then, some hypotheses of the rules of the optimal worker assignment are proposed and some numerical experiments are researched assuming the processing time as Erlang distribution. Finally, the other rules on other certain conditions are discussed.

• 정보보호학회논문지
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• 제27권6호
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• pp.1483-1490
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• 2017

스마트워치는 사용자가 착용하는 소형 스마트 기기로 연결성, 기능성 및 유용성을 위해 호스트 기기인 스마트폰과 페어링 과정을 필요로 한다. 페어링 과정 이후에는 사용자의 의식 없이도 스마트워치와 스마트폰 기기 간의 데이터 업데이트 및 백업 과정이 가능하며 스마트폰의 다양한 데이터가 복제되어 스마트워치로 넘어온다. 본 연구는 플랫폼별 스마트워치에 대해 스마트폰으로부터 복제되어 넘어오는 데이터를 사용 시점별로 추출 및 관찰하여 분석한다. 또한 스마트워치 사용자를 대상으로 실시한 보안관련 인식에 대한 설문조사를 바탕으로 데이터 추출 실험 결과에 따른 보안 및 개인 정보보호관점에서의 데이터별 위험도 평가를 수행하고 대응방안을 고찰한다.

• 한국산업보건학회지
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• 제29권3호
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• pp.278-288
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• 2019

Objectives: The objectives of this study are to summary controversy over health risks among semiconductor workers, to review major cancer risk results conducted in semiconductor operation and to evaluate occupational health activities in Korea for controlling hazardous agents generated in semiconductor operations Methods: Major occupational health issues that has been social controversies among semiconductor workers since 2007 were reviewed through an extensive literature, report and article review. Results: Since a female semiconductor worker aged 22 died from leukemia in 2007, job-association of a number of former semiconductor workers with various types of cancer and rare diseases have been denied by the Korea Workers' Compensation and Welfare Service (KWCWS), but some of them were later awarded compensation as an occupational disease by the administrative court. Two epidemiologic cancer risk studies conducted in Korea found increased risks in leukemia and non-Hodgkin's lymphoma among semiconductor workers. Various legal occupational health activities taken in semiconductor industry were found to fail to assess a complex characteristics of semiconductor operations, such as drastic changes in chemical use, processes, and technology, multiple exposure. National compensation regulation also showed the limitation to evaluate job-association of semiconductor workers who had worked in semiconductor operation. Conclusions: National legal measures should be taken to improve several occupational health activities and duties for protecting workers. In addition, the KWCWS program should be revised so that all workers who meet minimal job or environment associations can be compensated.