• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2395-2403
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• 2024

With the rapid development of DC high voltage accelerator, higher requirements have been raised for the design of DC high voltage power supply, requiring more stable high voltage with lower output ripple. Therefore, it also puts forward higher requirements for the parameter design of the voltage doubling rectifier circuit, which is the core component of the DC high voltage power supply. In order to obtain output voltage with better performance, the effects of the working frequency, the stage capacitance and the load resistance on the output voltage of the voltage doubling rectifier circuit are studied in detail by simulation. It can be concluded that the higher the working frequency of the transformer, the larger the stage capacitance, the larger the load resistance and the better the output voltage performance in a certain range. Based on this, a 2.5 MV voltage doubling rectifier circuit driven by a 120 kHz frequency transformer is designed, developed and tested for the power supply of the neutron source device towards BNCT. Experimental results show that this voltage doubling rectifier circuit can satisfy the design requirements, laying a certain foundation for the engineering design of DC high voltage power supply of neutron source device.

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.133-144
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• 2018

IEC 62278, the Railway System Safety Standard, requires for hazard analysis to prevent or control the hazard that the railway system may have. If hazard analysis is not performed sufficiently, there is a high probability that accidents will occur. For this reason, hazard analysis methods are actively studied. In this paper, we propose the hybrid hazard analysis method to combine two representative hazard analysis methods: reliability-based and system-theoretic. As the proposed method is complementary to existing ones, it covers both the hazard caused by failure of components and the hazard occurred from the unintended control between components. It applies to the development of a safety protection mechanism for multiple cruise control system that automatically control the speed of trains to avoid the collision among trains. As a result, we drive more safety requirements than the existing analysis methods and it turns out that the safety requirements protect the trains with respect to the identified hazards.

• Journal of KIISE:Software and Applications
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• v.33 no.2
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• pp.186-200
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• 2006

Analysis model focuses only on functional requirements and postpones nonfunctional requirements and implementation specific issues until subsequent design activities are undertaken. Based on the analysis models, the design activities are performed by refining and clarifying the analysis models. Thus, the quality of analysis models has a vast impact on the design models. Therefore, much effort should be taken to build correct analysis model. In this paper, we propose a set of structural constraints that analysis models of typical object-oriented development methods should satisfy. Three kinds of constraints are proposed: class related constraints, relation related constraints, and usage related constraints. For each constraint, formal definition and description with OCL are provided. In addition, through a case study with two medium-sired industrial systems, we demonstrated that the proposed approach can help to identify and correct serious deficiencies in object-oriented analysis models.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.478-480
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• 2011

The increasing interest in the hot cracking behavior of the high alloy metal weldment is placing stringent demands on the manufacturing techniques and performance requirements, and the manufacture employs the high quality and efficiency high alloy metal welding technology. This paper covers recent research trends of the hot cracking behavior of the high alloy metal weldment including the SCI-E analysis of published papers, research subjects and research institute analysis.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.475-477
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• 2011

The increasing interest in the laser brazing is placing stringent demands on the manufacturing techniques and performance requirements, and the manufacture employs the high quality and efficiency laser brazing technology. This paper covers recent research trends of the laser brazing technology including the SCI-E analysis of published papers, research subjects and research institute analysis.

• Journal of the Korean Home Economics Association
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• v.38 no.10
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• pp.117-132
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• 2000

The purpose of this study was to analysis on the current state of batterer intervention programs in South Korea. This study was composed of two parts. First, intervention programs for domestic violence batterer in foreign countries were reviewed. Second, bitterer programs in South Korea were explored. In order to expand these bitterer programs in South Korea, culturally appropriate intervention, more innovative research on comparison analysis of diverse intervention approaches, program impact, type of curriculum, and intervention protocol, evaluation criteria, requirements pertaining to program facilitators, political assistance, and coordinated community response and community service are strongly needed.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2014-2015
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• 2007

This paper deals with design and analysis of thrust magnetic bearing. Using the solutions obtained from equivalent magnetic circuit, we predict the electromagnetic characteristics such as thrust, time constant and power loss according to design parameters. And then, using non-linear finite element analysis, a detailed design is performed considering saturation in order to meet requirements.

• Journal of KIISE:Software and Applications
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• v.29 no.12
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• pp.860-872
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• 2002

Fault tree analysis is the most widely used saftly analysis technique in industry. However, the analysis is often applied manually, and there is no systematic and automated approach available to validate the analysis result. In this paper, we demonstrate that a real-time model checker UPPAAL is useful in formally specifying the required behavior of safety-critical software and to validate the accuracy of manually constructed fault trees. Functional requirements for emergency shutdown software for a nuclear power plant, named Wolsung SDS2, are used as an example. Fault trees were initially developed by a group of graduate students who possess detailed knowledge of Wolsung SDS2 and are familiar with safety analysis techniques including fault tree analysis. Functional requirements were manually translated in timed automata format accepted by UPPAAL, and the model checking was applied using property specifications to evaluate the correctness of the fault trees. Our application demonstrated that UPPAAL was able to detect subtle flaws or ambiguities present in fault trees. Therefore, we conclude that the proposed approach is useful in augmenting fault tree analysis.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.103-110
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• 2010

TPR(Total Physical Response) is a new representative learning method for children's education. Today's approach to TPR has focused on signals from a user which becomes input data in a human-computer interaction, but the accuracy of sensing from body signals(e. g. motion and voice) isn't so perfect that it seems difficult to apply on an education system. To overcome these limits, we suggest a mediating interface device which can detect the user's motion using correct numerical values such as acceleration and angular speed. In addition, we suggest new design requirements for the mediating device through analyzing children's behavior as human factors by ethnography research and protocol analysis. As a result, we found that; children are unskilled in physical control when they use objects; tend to lean on an object unconsciously with touch. Also their behaviors are restricted, when they use objects. Therefore a mediating device should satisfy new design requirements which are make up for unskilled handling, support familiar and natural physical activity.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.232-241
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• 2021

This study was conducted to prepare a countermeasure for turnover due to the effect of education satisfaction at franchise stores on turnover factors through the medium of education requirements. In the method of collecting data, 237 copies of the questionnaire method were used as the final data. The results are first, the analysis of educational requirements in general characteristics shows that academic background (F=5.655, p<).01), Analysis of the factors for turnover shows that position (t=-2.809, p<).Significant differences were shown in 01. Second, educational satisfaction is the educational requirement (r=-.16, p<).The correlation between 05) and turnover factors (r=-.18) is significant, and the educational requirement is turnover factors (r=.53, p<).It is shown to be a significant static correlation with 01. Third, designers (B=.25), t=2.332, p<.05) and educational requirements (B=.88, t=9.313, p<).001) has been shown to have significant static effects. Fourth, the educational requirements for educational satisfaction and turnover factors are significant (β=.52, p<).We can see that it is fully mediated by 001.Therefore, it is believed that it will be possible to investigate quarterly satisfaction and demand after communication and training with workers at direct stores, and reduce turnover through various curriculum education.