• 시스템엔지니어링학술지
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• 제15권1호
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• pp.51-59
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• 2019

After Fukushima Dai-ichi NPP accident, the need for implementation of diverse and flexible coping strategies (FLEX) became evident. However, to ensure the effectiveness of the safety strategy, it is essential to quantify the uncertainties associated with the station blackout (SBO) scenario as well as the operator actions. In this paper, a systems engineering approach for uncertainty analysis (UA) of a SBO scenario in advanced pressurized water reactor is performed. MARS-KS is used as a best estimate thermal-hydraulic code and is loosely-coupled with Dakota software which is employed to develop the uncertainty quantification framework. Furthermore, the systems engineering approach is adopted to identify the requirements, functions and physical architecture, and to develop the verification and validation plan. For the preliminary analysis, 13 uncertainty parameters are propagated through the model to evaluate the stability and convergence of the framework. The developed framework will ultimately be used to quantify the aleatory and epistemic uncertainties associated with an extended SBO accident scenario and assess the coping capability of APR1400 and the effectiveness of the implemented FLEX strategies.

• 한국멀티미디어학회논문지
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• 제22권3호
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• pp.349-356
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• 2019

When a prescription change occurs in the hospital depending on a patient's improvement status, pharmacists directly classify manually returned pills which are not taken by a patient. There are hundreds of kinds of pills to classify. Because it is manual, mistakes can occur and which can lead to medical accidents. In this study, we have compared YOLO, Faster R-CNN and RetinaNet to classify and detect pills. The data consisted of 10 classes and used 100 images per class. To evaluate the performance of each model, we used cross-validation. As a result, the YOLO Model had sensitivity of 91.05%, FPs/image of 0.0507. The Faster R-CNN's sensitivity was 99.6% and FPs/image was 0.0089. The RetinaNet showed sensitivity of 98.31% and FPs/image of 0.0119. Faster RCNN showed the best performance among these three models tested. Thus, the most appropriate model for classifying pills among the three models is the Faster R-CNN with the most accurate detection and classification results and a low FP/image.

• 시스템엔지니어링학술지
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• 제19권2호
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• pp.18-31
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• 2023

Exploring artificial intelligence and machine learning for nuclear safety has witnessed increased interest in recent years. To contribute to this area of research, a machine learning model capable of accurately predicting nuclear power plant response with minimal computational cost is proposed. To develop a robust machine learning model, the Best Estimate Plus Uncertainty (BEPU) approach was used to generate a database to train three models and select the best of the three. The BEPU analysis was performed by coupling Dakota platform with the best estimate thermal hydraulics code RELAP/SCDAPSIM/MOD 3.4. The Code Scaling Applicability and Uncertainty approach was adopted, along with Wilks' theorem to obtain a statistically representative sample that satisfies the USNRC 95/95 rule with 95% probability and 95% confidence level. The generated database was used to train three models based on Recurrent Neural Networks; specifically, Long Short-Term Memory, Gated Recurrent Unit, and a hybrid model with Long Short-Term Memory coupled to Convolutional Neural Network. In this paper, the System Engineering approach was utilized to identify requirements, stakeholders, and functional and physical architecture to develop this project and ensure success in verification and validation activities necessary to ensure the efficient development of ML meta-models capable of predicting of the nuclear power plant response.

• Earthquakes and Structures
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• 제4권3호
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• pp.241-264
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• 2013

Since the beginning of the twentieth century, the progressive and rapid spread of reinforced concrete (RC) has led to the adoption of mixed masonry-RC solutions, such as the confined masonry. However, together with structures conceived with a definite role for earthquake behaviour, the spreading of RC technology has caused the birth of mixed solutions inspired more by functional aspects than by structural ones, such as: internal masonry walls replaced by RC frames, RC walls inserted to build staircases or raising made from RC frames. Usually, since these interventions rise from a spontaneous build-up, any capacity design or ductility concepts are neglected being designed only to bear vertical loads: thus, the vulnerability assessment of this class becomes crucial. To investigate the non-linear seismic response of these structures, suitable models and effective numerical tools are needed. Among the various modelling approaches proposed in the literature and codes, the authors focus their attention on the equivalent frame model. After a brief description of the adopted model and its numerical validation, the authors aim to point out some specific peculiarities of the seismic response of mixed masonry-RC structures and their repercussions on safety verification procedures (referring in particular way to the non-linear static ones). In particular, the results of non-linear static analyses performed parametrically to various configurations representative of different interventions are discussed.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.1047-1057
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• 2016

Design engineering process for field programmable gate array (FPGA)-based reactor trip functions are developed in this work. The process discussed in this work is based on the systems engineering approach. The overall design process is effectively implemented by combining with design and implementation processes. It transforms its overall development process from traditional V-model to Y-model. This approach gives the benefit of concurrent engineering of design work with software implementation. As a result, it reduces development time and effort. The design engineering process consisted of five activities, which are performed and discussed: needs/systems analysis; requirement analysis; functional analysis; design synthesis; and design verification and validation. Those activities are used to develop FPGA-based reactor bistable trip functions that trigger reactor trip when the process input value exceeds the setpoint. To implement design synthesis effectively, a model-based design technique is implied. The finite-state machine with data path structural modeling technique together with very high speed integrated circuit hardware description language and the Aldec Active-HDL tool are used to design, model, and verify the reactor bistable trip functions for nuclear power plants.

• 한국간호교육학회지
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• 제26권3호
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• pp.322-331
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• 2020

Purpose: The purpose of this study was to investigate the validity and reliability of the Korean Version of the Grit (Grit-K) scale for nursing students in Korea. Methods: The participants in the study were 277 nursing students. Their grit was verified by using self-reports and the results of a questionnaire. Grit was translated into Korean and its content validity was verified by five experts. The validity of the instrument was verified through item analysis, exploratory factor analysis, and confirmatory factor analysis. Reliability verification was analyzed by using internal consistency reliability. Results: Two factors were identified through exploratory factor analysis and six items of the original instrument were found to be valid. In the confirmatory factor analysis, the validity of the instrument was verified as the model. The internal consistency reliability was also acceptable and Grit was found to be an applicable instrument. Conclusion: This study shows that the Korean Version of the Grit Questionnaire is a valid and reliable instrument to assess nursing students in Korea.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.181-184
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• 2009

증강현실 기반의 콘텐츠를 제작하는 데에는 많은 시간과 비용이 필요할 뿐만 아니라 컴퓨터공학, 가상현실, 증강현실, 3차원 그래픽스, 컴퓨터 시각과 같은 여러 분야에 숙련된 기술자의 도움이 필요하다. 이에 본 논문에서는 전문적인 엔지니어가 아닌 콘텐츠 작가나 일반인도 쉽고 빠르게 증강현실 콘텐츠를 저작할 수 있는 도구의 형태를 제안하고 있다. 목표로 하는 저작도구가 갖추어야 할 기술적인 요구사항인 "쉽고 빠른 저작", "풍부한 표현력", "검증 및 확인의 용이성", "대화식 저작 및 디버깅" 등을 만족시키기 위해, 정형적이고 시각적인 명세기법을 활용하고 스크립트 언어 인터프리터를 내장한 대화식 프레임워크 기반의 저작도구를 제안하고자 한다.

• 기본간호학회지
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• 제26권1호
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• pp.12-22
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• 2019

Purpose: This study was done to verify the self-directed learning instrument (SDLI) developed to measure self-directed learning ability in nursing students. Methods: The participants for the study were 425 nursing college students. Their self-directed learning was verified using self-reports and results through questionnaires. SDLI was translated into Korean through translation/reverse translation process and its content validity verified by five experts. The validity of the instrument was verified through item analysis, exploratory factor analysis, and confirmatory factor analysis. Reliability verification was analyzed using internal consistency reliability. Results: Four factors were identified through exploratory factor analysis and 20 items of the original instrument were found to be valid. In the confirmatory factor analysis, the validity of the instrument was verified as the model was valid. The internal consistency reliability was also acceptable and SDLI was found to be an applicable instrument. Conclusion: SDLI has been developed and verified by selecting nursing students as participants for the study. Use if SDLI is expected to improve the quality of self-directed learning in nursing education and to be used in future nursing research.

• 한국응급구조학회지
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• 제26권1호
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• pp.139-150
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• 2022

Purpose: This protocol aims to improve the simplicity of the existing two-person cardiopulmonary resuscitation (CPR) by focusing on chest compressions and artificial respiration, and classifying the roles within the scope that can be observed. Methods: In this study, the protocol was developed by forming an expert group consisting of a professor from the emergency and rescue department, a professor from the nursing department, and a first aid officer from the fire department. In addition, if the number of panels is 15 and the derived content validity ratio (CVR) value exceeds 0.49, a reference point that satisfies content validity at 95% reliability is presented. Results: All 11 performance items exceeded the CVR value of 0.49 to meet the reference point, and the CVR range of this protocol is 0.625 to 1.000. Conclusion: In order to improve the quality of three-person CPR, verification of simulation models and continuous protocol revision should be conducted by individuals specializing in various fields.

• 인터넷정보학회논문지
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• 제23권2호
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• pp.79-86
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• 2022

본 논문은 역공학 기반 소프트웨어 가시화를 통해 설계 개선 실현과 고품질화에 초점을 두고 있다. 앞으로의 4차 산업의 다양한 영역에서 새로운 기술과 복잡한 소프트웨어가 대두됨에 따라 안정성과 신뢰성을 겸비한 소프트웨어 검증이 이슈화되고 있다. 간단한 연산 소프트웨어부터 기계 학습기반의 데이터 지향 소프트웨어까지 다양한 소프트웨어 고품질화를 위한 역공학 기반 UML 설계 추출 및 가시화 방법을 제안한다. 이를 기반으로 목표 설계에 대한 정확도를 확인하고 코드 내부 복잡도 식별을 이용하여 설계 개선을 통한 소프트웨어 품질 향상을 기대한다.