• 한국안전학회지
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• 제14권2호
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• pp.116-121
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• 1999

When plate anchors are embedded in soft clay, they may undergo a deformation under the pressure of sustained load. The critical depth at which the transition from a shallow to a deep anchor takes place depends on the properties of soil. Laboratory model tests were performed for the short-term net ultimate uplift capacity of a circular anchors with respect to various embedment depths and moisture content in saturated kaolinite. The tests have been conducted with the anchor at two different moisture contents. Based on the model test results, empirical relationships between the net load, rate of strain, and time have been developed. In creep tests of kaolinite for load versus ultimate uplift capacity, the displacement of plate anchors rapidly increases during the primary stage but thereafter becomes constant over a period of time.

• 한국안전학회지
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• 제10권4호
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• pp.3-8
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• 1995

Anchors find their use in providing tie-back resistance for submerged footings, transmission towers, tunnels and ocean structures. Laboratory model teats were performed for the short-term net ultimate uplift capacity of a circular anchors with respect to various embedment depths and moisture content in saturated bentonite. The tests have been conducted with the anchor at two different moisture contents. Based an the model test results, empirical relationships between the net load, rate of strain, and time have been developed. Test results are as follows. 1) In creep tests for load versus ultimate uplift capacity, the displacement of plate anchors rapidly increases during the primary stage but thereafter becomes constant over a period of time. 2) Displacement increased with the increase of the sustain load and embedded ratio in soil. 3) If the load is less than or equal to 75% of the short-term ultimate uplift capacity, a complete pullout does not occur due to creep.

• 디지털산업정보학회논문지
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• 제7권1호
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• pp.85-93
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• 2011

2010 trend of Web services is Social Network Service. What does Social Network Service are like this? What could really be used? I also take advantage of future can I do? To elicit answers to the question of Social Network Service and the overall status of the root is used in the case Learn about the current utilization plan after the proposed research. The use of practices being applied to Social Network Service, the three theories were derived positive and negative aspects. Research based on more than the utilization of Social Network Service to build a social safety net to take advantage and use of learning aids were divided into suggestions. Utilized for building a social safety net, and when the reported channel to channel, the use of learning aids to learning that one day, one-on learning by applying the proposed total of four kinds of utilization.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2003년도 춘계학술대회
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• pp.299-304
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• 2003

Manufacturing companies must possess a new type of production system with characteristics of reconfigurability, reusability and scalability (Dove 1995), i.e. an agile manufacturing system. Such system will allow flexibility not only in producing a variety of part, but also in changing the system itself, which is a difference form flexible manufacturing systems. A fundamental early step in the reconfiguring process for agile manufacturing system is to develop a model that adequately describes the proposed systems, in order to be able to study and evaluate the impact of the reconfiguring decision on the system performance, before its construction. Therefore, in this paper, an Object & Knowledge-based Interval Timed Petri-Net (OKITPN) approach is proposed.

• 대한토목학회논문집
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• 제39권3호
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• pp.399-407
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• 2019

대한민국에서 건설업은 타 업종들과 비교하여 안전사고의 위험성이 가장 높게 나타난다. 따라서 건설업 내 안전성 향상을 도모하기 위해 여러 연구가 예전부터 진행이 되어 왔고, 본 연구에선 건설현장 영상 데이터를 기반으로 물체 탐지 및 분류 알고리즘을 이용해서 효과적인 안전모 자동탐지 시스템을 구축하여 건설현장 노동자들의 안전성 향상에 기여하고자 한다. 본 연구에서 사용된 알고리즘은 Convolutional Neural Network (CNN) 기반의 물체 탐지 및 분류 알고리즘인 Region-based Fully Convolutional Networks (R-FCN)이고 이를 Transfer Learning 기법을 사용하여 딥러닝을 실시하였다. ImageNet에서 수집한 1089장의 사람과 안전모가 포함된 영상으로 학습을 시행하였고 그 결과, 사람과 안전모의 mean Average Precision (mAP)은 각각 0.86, 0.83로 측정되었다.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.1015-1021
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• 2016

Structures, systems, and components (SSCs) important to safety of nuclear facilities shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions. Although SSC classification guidelines for nuclear power plants have been well established and applied, those for research reactors have been only recently established by the International Atomic Energy Agency (IAEA). Korea has operated a pool-type research reactor (the High Flux Advanced Neutron Application Reactor) and has recently exported another pool-type reactor (Jordan Research and Training Reactor), which is being built in Jordan. Korea also has a plan to build one more pool-type reactor, the Kijang Research Reactor, in Kijang, Busan. The safety classification of SSCs for pool-type research reactors is proposed in this paper based on the IAEA methodology. The proposal recommends that the SSCs of pool-type research reactors be categorized and classified on basis of their safety functions and safety significance. Because the SSCs in pool-type research reactors are not the pressure-retaining components, codes and standards for design of the SSCs following the safety classification can be selected in a graded approach.

• Nuclear Engineering and Technology
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• 제50권7호
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• pp.1168-1172
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• 2018

This study went beyond making an indicator simply based on theoretical arguments, and explored a wide spectrum of different types of perceptions about energy safety to make a concept of energy safety for the Korean society. The energy safety schemata of people can be divided into three types. Type1 is concern about multi-level risks-responsibility-centric, type2 is concern about security and personal burden-expertise-centric, and type3 is concern about health and personal burden-responsibility-centric. Questions were designed on the basis of the characteristics, differences and commonalities of the three types of perceptions, explored through the Q methodology, and Koreans' perception of nuclear safety was examined. Based on the results of this research the following components of trust in nuclear safety were derived, risk perception, responsibility, honesty, expertise and procedural justification. The items for specifically evaluating them were developed, and factor analysis was conducted, and as a result, the validity of each item was proven. The components of the nuclear safety trust indicator do not exist independently, but influence each other continuously through interactions. For this reason, rather than focusing on any one of them, laws and systems must be improved first so that they can move together in one big frame.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2055-2061
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• 2022

In the event of a short-circuit accident on a 4.16 kV non-safety bus, the voltage is temporarily lowered as backflow occurs on the safety bus. In such cases, the undervoltage relay of the safety bus shall not pick up the undervoltage so as not to interfere with the operation of the safety motors. The aim of this study is to develop an adaptive undervoltage protection scheme for the 4.16 kV safety bus considering the faults on the 13.8 kV and 4.16 kV non-safety buses connected to secondary windings of the three winding transformers, UAT and SAT. The result of this study will be the adaptive undervoltage protection scheme for the safety bus of nuclear power plants satisfying functional requirements of the safety related medium voltage motors. The adaptive undervoltage protection scheme can be implemented into an integrated digital protective relay to make user friendly and reliable protection scheme.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1814-1820
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• 2023

Safety classification of systems, structures, and components (SSC) is an essential activity for nuclear reactor design and operation. The current regulatory trend is to require risk-informed safety classification that considers first, the severity, but also the frequency of SSC failures. While safety classification for nuclear power plants is covered in many regulatory and scientific publications, research reactors received less attention. Research reactors are typically of lower power but, at the same time, are less standardized i.e., have more variability in the design, operational modes, and operating conditions. This makes them more challenging when considering safety classification. This work presents the Integrated Risk-Informed Safety Classification (IRISC) procedure which is a novel extension of the IAEA recommended process with dedicated probabilistic treatment of research reactor designs. The article provides the details of probabilistic analysis performed within safety classification process to a degree that is often missing in most literature on the topic. The article presents insight from the implementation of the procedure in the safety classification for the MARIA Research Reactor operated by the National Center for Nuclear Research in Poland.

• 한국방사선학회논문지
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• 제17권5호
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• pp.791-800
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• 2023

본 연구는 부산에 거주하는 시민을 대상으로 방사선 사회안전망 구축과 시민의 안전의식 및 안전 문화 정착에 대해 조사하여 방사선으로부터 안전한 사회를 조성할 수 있는 기틀을 마련하고자 수행하였다. 자료수집은 온라인 설문을 실시하고, 200부의 설문을 분석하였다. 자료는 SPSS Window Ver 28.0을 이용하여 분석하였다. 집단 간 차이 검증을 위해 t-test와 일원배치분산분석(one way ANOVA)을 실시하였으며, 변수 간의 연관성을 확인하기 위하여 상관분석을 실시하였다. 그리고 변수 간 미치는 영향을 확인하기 위하여 다중선형회귀분석(Multiple Linear Regression Analysis)을 실시하였다. 그 결과 첫째, 사회안전망 구축, 시민의 안전의식, 안전 문화 정착에서 성별은 남자, 연령은 20대, 학력은 고등학교 졸업 그룹의 점수가 높게 나타났다. 그중 성별에서 사회안전망 구축은 유의수준 .01, 안전 문화정착은 유의수준 .05에서 통계적 차이를 보였다. 직업에서는 방사선 사회안전망 구축에 대해서 전문직 종사자와 서비스직 종사자가 유의수준 .05에서 통계적 차이를 나타냈다. 둘째, 다중회귀분석 결과 방사선 사회안전망 구축의 하부요인인 '지자체 방사선 안전교육'이 시민의 안전의식과 안전 문화 정착에 정적인 영향을 끼치는 것으로 나타났다. 셋째, 사회안전망 구축과 시민의 안전의식, 안전 문화 정착 간 상관관계 분석 결과 정적 상관을 나타냈다. 따라서, 방사선 사회안전망 구축이 잘되어 있으면 시민의 안전의식과 안전문화 정착에도 긍정적인 영향을 미치는 것으로 판단된다.