• Nuclear Engineering and Technology
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• 제52권2호
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• pp.230-237
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• 2020

In this part, an implicit time dependent solution is presented for the Boltzmann transport equation discretized by the analytic coarse mesh finite difference method (ACMFD) over the spatial domain as well as the simplified P₃ (SP₃) for the angular variable. In the first part of this work we proposed a SP₃-ACMFD approach to solve the static eigenvalue equations which provide the initial conditions for temp dependent equations. Having solved the 3D multi-group SP₃-ACMFD static equations, an implicit approach is resorted to ensure stability of time steps. An exponential behavior is assumed in transverse integrated equations to establish a relationship between flux moments and currents. Also, analytic integration is benefited for the time-dependent solution of precursor concentration equations. Finally, a multi-channel one-phase thermal hydraulic model is coupled to the proposed methodology. Transient equations are then solved at each step using the GMRES technique. To show the sufficiency of proposed transient SP₃-ACMFD approximation for a full core analysis, a comparison is made using transport peers as the reference. To further demonstrate superiority, results are compared with a 3D multi-group transient diffusion solver developed as a byproduct of this work. Outcomes confirm that the idea can be considered as an economic interim approach which is superior to the diffusion approximation, and comparable with transport in results.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.114-120
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• 2014

In this paper, a method for multi-physics analysis of the temperature-dependent properties of an oil-immersed transformer is discussed. To couple thermal fields with electromagnetic and fluid fields, an algorithm employing a user defined function (UDF) is proposed. Using electromagnetic analysis, electric power loss dependent on temperature rise is calculated; these are used as input data for multi-physics analysis in order to predict the temperature rise. A heat transfer coefficient is applied only at the outermost boundary between transformer and the atmosphere in order to reduce the analysis region. To verify the validity of the proposed method, the predicted temperature rises in high-voltage (HV) and low-voltage (LV) windings and radiators were compared with the experimental values.

• 한국융합학회논문지
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• 제11권12호
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• pp.161-176
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• 2020

본 연구는 부모구성(부모, 한부모)에 따라 부모의 양육태도(감독, 애정, 합리적 설명)가 자아탄력성을 매개로 아동의 삶의 만족도에 미치는 영향력에 차이가 있는지 검증하고자 하였다. 이를 위해 한국청소년정책연구원의 KCYPS 초4 패널 데이터에서 총 310명의 데이터를 활용해 다집단분석을 실시하였다. 분석결과 첫째, 애정적 양육태도는 부모구성에 상관없이 삶의 만족도에 유의미한 정적 영향을 미쳤다. 둘째, 양육태도(애정, 감독)는 한부모가정 집단에서 자아탄력성에 유의미한 정적 영향을 미쳤으나 부모가정 집단에서는 유의한 영향을 미치지 않았다. 셋째, 애정적인 양육태도는 한부모가정 집단에서만 자아탄력성을 매개하여 자녀의 삶의 만족도에 유의한 영향을 미쳤다. 본 연구는 아동의 삶의 만족에 영향을 주는 요인들의 구조적 관계를 검증하고, 부모구성에 따라 그 양상이 달라짐을 밝혔다는 것에 의의가 있다. 마지막으로 연구의 한계와 실무적 개입방법, 후속 연구에서의 방향성 등을 제시하였다.

• 품질경영학회지
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• 제31권1호
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• pp.21-41
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• 2003

The purpose of this research is to identify if psychological temptation, site quality and sense of community influence user's flow and addiction and if causalities among flow, addiction, customer satisfaction and customer loyalty are different between Korean and Japanese online games. To perform our research, we use MCSF(Multi-group Confirmatory Factor Analysis) and MSEM(Multi-group Structural Equation Model). The empirical results of SEM(Structural Equation Model) including high-order factor analysis indicate that all of paths in our model are the same for both countries. Therefore, site quality and sense of community have impacts on the flow, while on the other hand, psychological temptation has impacts on the addiction. Customer satisfaction and loyalty are positively related not with the addiction but with the flow. In addition, customer loyalty is significantly influenced by the flow and the customer satisfaction. In Conclusion, the empirical results of MSEM(Multi-group Structural Equation Model) indicate sense of community to flow, flow to loyalty and customer satisfaction to loyalty are different between Korea and Japan. This indicates that companies to penetrate into Japa online game industry should have a concern with Japanese Social and Cultural features and to develop strategies which correspond with Japanese culture.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1789-1803
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• 2022

RAST-F is a new full-core analysis code based on the two-step approach that couples a multi-group cross-section generation Monte-Carlo code MCS and a multi-group nodal diffusion solver. To demonstrate the feasibility of using MCS/RAST-F for fast reactor analysis, this paper presents the coupled nodal code verification results for the MET-1000 and CAR-3600 benchmark cores. Three different multi-group cross-section calculation schemes are employed to improve the agreement between the nodal and reference solutions. The reference solution is obtained by the MCS code using continuous-energy nuclear data. Additionally, the MCS/RAST-F nodal solution is verified with results based on cross-section generated by collision probability code TULIP. A good agreement between MCS/RAST-F and reference solution is observed with less than 120 pcm discrepancy in k_eff and less than 1.2% root-mean-square error in power distribution. This study confirms the two-step approach MCS/RAST-F as a reliable tool for the three-dimensional simulation of reactor cores with fast spectrum.

• 복식
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• 제61권10호
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• pp.119-134
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• 2011

The present study proposes and tests an integrative model for global consumers to examine the relation among fashion marketing mix, brand attitude, brand loyalty, and purchase intention in the jeans market. The questionnaire surveys 692 consumers in the United States, China, and France. The statistical analysis methods that are used are as follows: frequency analysis, factor analysis, SEM analysis, and multi-group analysis. The results show that fashionability, perceived quality, and advertising have a direct and also a positive effect on brand attitude; however, advertising didn't have a direct effect on purchase intention. In addition, the results of the SEM analysis show that brand attitude leads to brand loyalty, while also showing a direct and indirect positive effect on purchase intention. Furthermore, the multi-group analysis reveals significant differences in SEM among countries such as the United States, China, and France.

• International Journal of Aeronautical and Space Sciences
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• 제5권2호
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• pp.71-76
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• 2004

This paper describes the antenna analysis of the multi-beam for communicationsatellite. The design core parameters of the antenna system are optimal antennadiameter, feed horn type and hom size, F/D, and the coordinate of offset horns. Thepaper deals with the method to determine design core parameters of optimal antennadiameter, feed horn type and horn size. F/D, and the coordinate of offset horns, andthe performances of design result.

• 공학교육연구
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• 제23권2호
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• pp.49-60
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• 2020

The purpose of this study is to empirically verify whether there are differences according to group characteristics in the effect of job characteristic requirements on practice performance in university long-term on-site training. Specifically, the relationship between job characteristics (job scope, job content, coaching, benefits), practical satisfaction, and occupational competencies was examined according to the group characteristics (gender types, major types, corporation types). For this purpose, the survey data were collected and analyzed for 752 students who participated in K university long-term on-site training. As a result of the analysis, first, it was found that the job characteristics (job scope job content, coaching, benefits) had structural relationship affecting occupational competence through mediation of practice satisfaction. Second, As for the differences according to the group characteristics, there were differences in the relations. Based on the result, theoretical and practical implications and follow-up studies were proposed.

• 한국노년학
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• 제40권1호
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• pp.33-49
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• 2020

본 연구는 사회적 배제의 잠재유형을 구분하고 노후의 경제적 불안에 미치는 영향을 실증적으로 분석하였다. 또한 주관적 계층의식에 따라 그 영향력이 달라지는지를 함께 살펴보고자 하였다. 이를 위해 2016년 한국종합사회조사(KGSS) 14차 자료를 사용하여, 조사 당시 기준 만 18세의 성인남녀 1,041명의 응답지를 분석하였다. STATA14와 MPLUS 7 통계프로그램을 이용하여 기술통계분석과 t-test, 잠재계층분석(LCA), 잠재집단에 대한 다항로지스틱분석을 실시하였다. 마지막으로 다중회귀분석을 실시하여 변수 간 영향관계 및 조절 효과를 확인하였다. 연구결과 사회적 배제의 유형은 3집단으로 나타났으며, 사회활동배제집단(49.3%), 다차원적 배제집단(30.9%), 사회 활동 적극집단(19.7%)의 순으로 나타났다. 사회활동배제집단은 경제, 고용, 건강 배제의 가능성이 가장 낮지만, 공식/비공식 사회활동의 배제가 두드러진 집단이며, 다차원적 배제집단은 모든 영역에서 배제를 경험할 가능성이 50% 이상인 집단으로 나타났다. 사회활동 적극집단은 비공식 사회활동에 매우 적극적으로 참여하는 것이 특징인 집단이다. 다항로지스틱 분석결과 사회활동배제집단은 다른 집단에 비해 청년층이 많이 포함되었으며, 다차원적 배제집단에는 배우자가 없는 여성노인이 많이 포함되어 있는 것으로 나타났다. 마지막으로 다중회귀분석 결과 사회적 배제 유형은 주관적 계층의식과 상호작용하여 노후의 경제적 불안에 영향을 미치는 것으로 나타났다. 이러한 연구결과를 바탕으로 노후의 경제적 불안을 예방하기 위한 정책적·실천적 방안을 제언하였다.

• Mycobiology
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• 제43권3호
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• pp.210-217
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• 2015

A seed-borne fungus, Curvularia sp. EML-KWD01, was isolated from an indigenous wheat seed by standard blotter method. This fungus was characterized based on the morphological characteristics and molecular phylogenetic analysis. Phylogenetic status of the fungus was determined using sequences of three loci: rDNA internal transcribed spacer, large ribosomal subunit, and glyceraldehyde 3-phosphate dehydrogenase gene. Multi loci sequencing analysis revealed that this fungus was Curvularia spicifera within Curvularia group 2 of family Pleosporaceae.