• Nuclear Engineering and Technology
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• 제32권6호
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• pp.537-548
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• 2000

The requirement of ultra high reliability of the safety critical software can not be demonstrated by testing alone. The specification based on formal method is recommended for safety system software. But there exist various kinds of formal methods, and this variety of formal method is recognized as an obstacle to the wide use of formal method. In this paper six different formal method have been applied to the same part of the functional requirements that is calculation algorithm intensive. The specification results were compared against the criteria that is derived from the characteristics that good software requirements specifications should have and regulatory body recommends to have. The application experience shows that the critical characteristics should be defined first, then appropriate method has to be selected. In our case, the Software Cost Reduction method was recommended for internal condition or calculation algorithm checking, and statechart method is recommended for the external behavioral description.

• 대한수의학회지
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• 제61권3호
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• pp.20.1-20.9
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• 2021

This study is to develop a new scoring system for rating Hazard analysis and critical control points prerequisite evaluation items for meat shops to provide a more objective and accurate evaluation of food safety compliance. The importance of each item was measured by looking at the hazard severity level and the rate of non-compliance associated with it. It was found that the new scoring system is more stringent and gives a clearer picture of compliance with the most critical safety standards, and therefore is expected to have a positive effect on the hygiene and safety of livestock products.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.19-29
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• 2021

This paper presents the validation of the MCS code for critical safety analysis with burnup credit for the spent fuel casks. The validation process in this work considers five critical benchmark problem sets, which consist of total 80 critical experiments having MOX fuels from the International Criticality Safety Benchmark Evaluation Project (ICSBEP). The similarity analysis with the use of sensitivity and uncertainty tool TSUNAMI in SCALE was used to determine the applicable benchmark experiments corresponding to each spent fuel cask model and then the Upper Safety Limits (USLs) except for the isotopic validation were evaluated following the guidance from NUREG/CR-6698. The validation process in this work was also performed with the MCNP6 for comparison with the results using MCS calculations. The results of this work showed the consistence between MCS and MCNP6 for the MOX fueled criticality benchmarks, thus proving the reliability of the MCS calculations.

• 한국산학기술학회논문지
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• 제17권6호
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• pp.598-608
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• 2016

본 논문은 임상간호사의 환자안전역량 강화를 위한 기초자료로 제공하기 위해 환자안전역량에 영향을 미치는 요인을 파악하고자 비판적 사고성향, 문제해결능력 및 자기효능감을 독립변수로 정하여 서술적 조사연구를 시행하였으며, 중소병원에 근무하는 6개월 이상 경력의 임상간호사 373명을 대상으로 하였다. 자료분석 결과 환자안전역량에 영향을 미치는 요인은 문제해결능력(${\beta}=.403$, p<.001)이 가장 큰 것으로 나타났으며 자기효능감(${\beta}=.156$, p=.005), 환자안전사고 보고 경험(${\beta}=.137$, p=.002), 비판적 사고성향(${\beta}=.130$, p=.018) 순으로 영향을 미치는 것으로 나타났다. 이들 변수는 대상자의 환자안전역량에 대해 42.3%(adj $R^2=.423$) 설명하였다(F=20.305, p<.001). 비판적 사고성향, 문제해결능력, 자기효능감은 학부과정에서부터 강조되는 것으로 실제 의료현장에서 환자의 안전을 최일선에서 다루는 임상간호사에게는 더욱이 필요한 요인이라고 볼 수 있다. 따라서 환자안전역량 강화를 위해서는 의료기관 자체 내에서 임상간호사를 위한 비판적 사고성향, 문제해결능력 및 자기효능감을 높이기 위한 교육프로그램과 같은 다양한 전략과 활동들이 요구된다고 생각된다. 또한 환자안전을 최우선으로 생각하고 환자안전사고 발생 시 적극적인 보고를 독려하는 한편 환자안전사고 보고를 저해하는 요인들을 면밀히 사정하여 보완하여 보고율 향상과 더불어 환자안전역량 강화에도 힘써야 할 것이다.

• International Journal of Safety
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• 제3권1호
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• pp.38-46
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• 2004

This paper introduces the software life-cycle V&V (verification and validation) tasks for the KNICS (Korea nuclear instrumentation and control system) project. The objectives of the V&V tasks are mainly to develop a programmable logic controller (PLC) for safety critical instrumentation and control (I&C) systems, and then to apply the PLC to developing the prototype of an engineered safety features-component control system (ESF-CCS) in nuclear power plants. As preparative works for the software V&V, various kinds of software plans and V&V task procedures have been developed according to the software life-cycle management. A number of software V&V tools have been adopted or developed to efficiently support the V&V tasks. The V&V techniques employed in this work include a checklist-based review and inspection, a requirement traceability analysis, formal verification, and life-cycle based software testing.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 춘계학술발표회요약집
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• pp.178.1-178
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• 2001

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3241-3251
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• 2023

The potential for recriticality and sub-critical boron concentrations is analyzed during the relocation of the fuel rods in the assembly, which we call late phase of a severe accident, via coupling between MELCOR and whole-core Monte Carlo analyses by Serpent 2. The recriticality, initiated during the early phase, is found to maintain when the fuel assemblies containing intact fuel rods are submerged by the cooling water. It is also found that the effect of the negative reactivity insertion via remaining fission products in the fuel debris increases as the burnup increases. The sub-critical boron concentrations during the late phase are found to be 76~544 ppm lower than those during the early phase. Therefore, it can be concluded that the boron concentration that prevents recriticality not only during the early phase but also during the late phase is the sub-critical boron concentration during the early phase.

• 디지털융복합연구
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• 제16권12호
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• pp.511-521
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• 2018

본 연구의 목적은 간호대학생의 비판적 사고성향과 임상의사결정능력 및 환자안전 지식, 태도가 임상실습 시 환자안전수행능력에 미치는 영향을 조사하고 이들 변수간의 관련성을 파악하여 환자안전수행능력의 향상을 위한 중재 프로그램 개발의 기초자료를 마련하기 위함이다. 자료분석은 SPSS 21.0 프로그램을 이용하여 t-tests, one-way ANOVA 등을 실시하였다. 연구결과, 대상자의 환자안전 수행능력은 비판적 사고성향(r=.278, p=.001)과 양적 상관관계,. 임상의사결정능력(r=.202, p=.014)과 양적 상관관계, 환자안전 태도(r=.421, p<.001)와 양적 상관관계가 있었다. 환자안전 수행능력에 미치는 영향요인은 성별(${\beta}=.175$, p=.031), 환자안전 교육(${\beta}=-2.266$, p=.025), 비판적 사고성향(${\beta}=3.354$, p=.001), 환자안전 태도(${\beta}=.368$, p<.001)로서 설명력은 31.5%의 영향력을 보였다(R2=.561, F=4.56 p<.001). 간호대학생의 임상실습 교육에 필요한 환자안전 수행능력을 증진하기 위해서 비판적 사고성향, 임상의사결정능력, 환자안전교육에 대한 교과 과정의 수립이 필요하다.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.138-145
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• 2019

With the application of digital technology to safety-critical infrastructures, cyber-attacks have emerged as one of the new dangerous threats. In safety-critical infrastructures such as a nuclear power plant (NPP), a cyber-attack could have serious consequences by initiating dangerous events or rendering important safety systems unavailable. Since a cyber-attack is conducted intentionally, numerous possible cases should be considered for developing a cyber security system, such as the attack paths, methods, and potential target systems. Therefore, prior to developing a risk-informed cyber security strategy, the importance of cyber-attacks and significant critical digital assets (CDAs) should be analyzed. In this work, an importance analysis method for cyber-attacks on an NPP was proposed using the probabilistic safety assessment (PSA) method. To develop an importance analysis framework for cyber-attacks, possible cyber-attacks were identified with failure modes, and a PSA model for cyber-attacks was developed. For case studies, the quantitative evaluations of cyber-attack scenarios were performed using the proposed method. By using quantitative importance of cyber-attacks and identifying significant CDAs that must be defended against cyber-attacks, it is possible to develop an efficient and reliable defense strategy against cyber-attacks on NPPs.

• 한국항행학회논문지
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• 제21권1호
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• pp.50-57
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• 2017

최근 국내에서 추진된 항공 관련 안전필수시스템 기술 개발 사업들이 중도에 종료되거나 최종 단계에서 실용화되지 못하는 사례가 종종 발생했다. 사업실패의 원인은 여러 가지 요인이 있겠지만 본 연구에서는 불완전한 시험평가 절차에 주안점을 두고 관련 연구를 수행하였다. 일반적으로 안전필수시스템의 시험평가 프로세스는 시스템의 전 수명주기에 걸쳐 분포되고 단계별 연속성을 가져야 하며 시스템 설계 및 획득 전략의 성숙도에 따라 다양한 방법으로 실행될 수 있다. 본 논문의 목적은 국내 안전필수 항행시스템 개발 사업의 리스크를 줄이고 성공률을 높이기 위한 방안으로 국내외 시험평가 프로세스를 분석하여 새로운 전략을 제시하는 것이다. 먼저 안전필수시스템에 대한 검증 및 확인 기법에 대해 토의하고 선진기관의 시험평가 프로세스 및 절차와 국내 현황을 분석한 뒤 국내외 시험평가 프로세스를 비교함으로써 불완전한 시험평가 절차에 대한 보완책을 제시하였다.