• Nuclear Engineering and Technology
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• 제34권3호
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• pp.250-258
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• 2002

This Paper is to apply the well-established coarse mesh finite difference(CMFD) method to the method of characteristics(MOC) transport calculation as an acceleration scheme. The CMFD problem is first formulated at the pin-cell level with the multi-group structure To solve the cell- based multi-group CMFD problem efficiently, a two-group CMFD formulation is also derived from the multi-group CMFD formulation. The performance of the CMFD acceleration is examined for three test problems with different sizes including a realistic quarter core PWR problem. The CMFD formulation provides a significant reduction in the number of ray tracings and thus only about 9 ray tracing iterations are enough for the realistic problem. In computing time, the CMFD accelerated case is about two or three times faster than the coarse-mesh rebalancing(CMR) accelerated case.

• 한국산학기술학회논문지
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• 제21권10호
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• pp.379-385
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• 2020

본 논문은 전투차량에 장착되는 온수히터의 코어부위 냉각수 누수방지를 위한 설계에 관한 것이다. 온수히터는 가온된 냉각수를 승무원실의 히터 코어에 흘려 난방하는 장치로, 전투차량 운용 시 온수히터 코어 부위의 냉각수 누수현상이 발생하는 문제점이 확인되었다. 이 문제점은 주로 코어의 탱크와 튜브 부위의 접합부에서 발생하였는데, 이 부위가 취약하여 고압을 가압하였을 때 누수가 발생한 것으로 추정하였다. 이 문제를 개선하기 위하여 용접방식을 개선하고 온수히터 코어 말단 부위를 높은 압력에서 견딜 수 있는 구조로 변경하였다. 기존 코어와 개선 코어에 대하여 순차적으로 압력을 가하였을 때 기존 코어는 7.0 kgf/㎠에서 누수가 발생하였으며 개선 코어는 17.0 kgf/㎠까지 견고하게 구조를 유지하여 개선이 되었음을 입증하였다. 마지막으로 개선한 구조의 체계 적합성을 입증하기 위하여 성능시험 및 환경시험을 실시하였다. 본 논문의 연구결과를 바탕으로 제작된 개선 온수히터는 전투차량에 적용될 예정이며, 신뢰성 확보를 통한 방위력 향상과 유사 장비의 설계 및 고장분석에도 참고자료가 될 것으로 기대된다.

• 융합정보논문지
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• 제10권1호
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• pp.44-50
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• 2020

본 연구는 융합시뮬레이션교육이 간호학생의 문제해결능력과 자기효능감 및 핵심기본간호술 수행자신감에 미치는 효과를 규명하고자 실험군 97명, 대조군 87명을 대상으로 시행된 비동등성 대조군 사후설계 유사실험연구이다. 수집된 자료는 independent t-test, Chi-square test 및 Pearson's correlation으로 분석하였다. 연구결과 융합시뮬레이션 교육 후 실험군의 문제해결능력(t=-2.04, p=.043) 및 핵심기본간호술 수행자신감(t=5.31, p <.001)이 유의하게 높았다. 본 연구결과는 4학년 간호학생에게 세부 전공별 간호단위를 통합한 융합시뮬레이션 교육을 적용하여 간호학생의 임상수행능력을 향상시킬 수 있는 방안을 모색하는 근거를 마련함에 의의가 있다. 효과적인 융합시뮬레이션 교육을 위해 다양한 교과목 콘텐츠의 지속적인 개발 및 그 효과를 검증하는 반복 및 융합 연구를 제안한다.

• 전기학회논문지
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• 제61권10호
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• pp.1536-1541
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• 2012

The study analyzed problems by iron core structure of the three phased transformer on asymmetric three phase lines, which included line disconnections, ground faults, COS OFF, and unbalanced loads on the power distribution system. In particular, by analyzing PT combustion cases within the MOF, the study was able to analyze the combustion cause of the core-type transformer and its effect on the system, conduct simulations and practice demonstrations on the characteristics for each iron core structure of the three phase transformer using PSCAD/EMTDC, and suggest measures to prevent the combustion of the core-type transformer.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.326-330
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• 2005

Aircraft composite structure with honeycomb core experiences core crush problem in manufacturing. To prevent core crush additional processes are needed such as core stabilization and prepreg material tie-down and this is the cause of increasing cost. Recent study shows that high friction prepreg prevent core crush without additional process. This paper presents the analysis of high frictional material which attracts lots of interests through physical property, mechanical property and microscopic

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(1)
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• pp.27-32
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• 1996

In this study, the boundary element method (BEM) is used to treat the homogenization of the baffle and reflector. First, the multigroup diffusion equations (MDE) within the core are solved using BEM as a source problem under the assumption that the core material is uniformly distributed. Then, the solution to MDE for the water reflector which should be extended infinite can be attained from a boundary source problem also via BEM. Finally, these two solutions are coupled through albedos of the slab-shaped baffle so that one could obtain heterogeneous interface currents and fluxes between the core and the baffle/reflector resulting in the location-dependent equivalent parameters for the baffle/reflector.

• 공학교육연구
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• 제20권5호
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• pp.50-58
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• 2017

The purpose of this study is to explore the core competencies of the Fourth Industrial Revolution in the major newspaper articles of social network analysis and to examine the core competencies required by each field and target. To do this, we reviewed prior research focusing on core competency concepts and core competencies of engineering students, and analyzed 227 articles related to core competencies of the 4th Industrial Revolution, focusing on five major newspapers. Through analysis, we analyzed social network with 118 refined core competency keywords. As a result of the research, it was found that core competencies of the 4th Industrial Revolution are the degree centrality in terms 'creativity', 'problem solving ability', 'convergence ability', 'collaboration ability', 'conductivity', 'software ability', 'human literacy', 'personality' order. Also, as a result of the analysis of the ego centric network by field and target, the required core competencies of university and industry were found to be different. Through these discussions, it is necessary to restructure the core competence of engineering students in order to nurture the engineering talents necessary for the 4th Industrial Revolution.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.33-42
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• 2016

Spacer grids play an important role in maintaining the proper form of the fuel assembly structure and ensuring the safety of reactor core design. This study applies the Monte Carlo method to the analysis of the neutronics effects of spacer grids in a typical pressurized water reactor (PWR). The core problem used to analyze the neutronics effects of spacer grids is a modified version of Korea Advanced Institute of Science and Technology benchmark problem 1B, based on an Advanced Power Reactor 1400 (APR1400) core model. The spacer grids are modeled and added to this test problem in various ways. Then, by running MCNP5 for all cases of spacer grid modeling, some important numerical results, such as the effective multiplication factor, the spatial distributions of neutron flux, and its energy spectrum are obtained. The numerical results of each case of spacer grid modeling are analyzed and compared to assess which type has more advantages in accuracy of numerical results and effectiveness in terms of geometry building. The conclusion is that the most realistic modeling for Monte Carlo calculation is the "volume-preserving" streamlined heterogeneous spacer grids, but the "banded" dissolution spacer grids modeling is a more practical yet accurate model for routine (deterministic) analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.556-559
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• 2006

We successfully developed a high performance and highly reliable blazed GxL device with a high optical efficiency and a high contrast ratio. The device demonstrated superior resistance against a high power laser, which is suitable for a large-area laser projector. We operated the world's largest laser projection screen using this device at the 2005 World Exposition in Aichi, Japan, problem free.

• Journal of Information Technology Applications and Management
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• 제27권2호
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• pp.23-36
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• 2020

The promulgation of the overall framework of Chinese students' development of core literacy has made the implementation of core literacy into specific teaching activities an urgent problem to be solved in the field of education. Based on the analysis of the problems existing in the undergraduate education under the mode of emphasizing theory and neglecting practice, this paper constructs the practical teaching system of Database Principle Course Based on the core quality, expounds the implementation strategy of practical teaching, and probes into how to train the students in the practical teaching of database principle Cultivate scientific spirit, learning ability, practical innovation, responsibility and other core literacy. After 5 rounds of practice, students have achieved better development in independent development and collaborative work, and their awareness of practical innovation has been significantly improved.