• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2112-2124
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• 2023

With the rise of economic and safety standards for nuclear reactors, new concepts of Gen-IV reactors and modular reactors showed more complex designs that challenge current tools for reactor physics analysis. A Monte Carlo (MC) two-step method was proposed in this work. This calculation scheme uses the continuous-energy MC method to generate multi-group cross-sections from heterogeneous models. The multi-group MC method, which can adapt locally-heterogeneous models, is used in the core calculation step. This calculation scheme is verified using a Gen-IV modular lead-based fast reactor (LFR) benchmark case. The influence of homogenized patterns, scatter approximations, flux separable approximation, and local heterogeneity in core calculation on simulation results are investigated. Results showed that the cross-sections generated using the 3D assembly model with a locally heterogeneous representation of control rods lead to an accurate estimation with less than 270 pcm bias in core reactivity, 0.5% bias in control rod worth, and 1.5% bias on power distribution. The study verified the applicability of multi-group cross-sections generated with the MC method for LFR analysis. The study also proved the feasibility of multi-group MC in core calculation with local heterogeneity, which saves 85% time compared to the continuous-energy MC.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.4
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• pp.663-686
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• 2017

The purpose of this study was to identify the effects of convergent approach of mathematics education on students' problem-solving ability and self-efficacy by designing and applying mathematics curriculum based on STEAM. The results are as follows. First, the test results between the two groups did not show any statistically significant difference in terms of problem solving ability, but the experimental group showed a higher average score than the comparative group. Compared with the standard deviation of the experimental group, It can be seen that the level of difference between students is great. This suggests that STEAM-based mathematics lessons have a positive effect on the problem solving ability of low-level students. Second, the results of the self-efficacy t-test of STEAM-based mathematics class showed statistically significant results at a 5% significance level. In the sub-domain, the preference for the difficulty of the mathematics task, except math self-confidence and the math self-regulation efficacy, were statistically significant at a 5% significance level. This study shows that STEAM-based mathematics classes have a positive effect on the students' positive aspects. Through the STEAM program, students learn that mathematics is connected with other fields, and it provides an opportunity to explore on their own, and they more became interested, motivated, and achievement. Also, through the results of the STEAM-based mathematics class, it can be seen that the expressive power and self-confidence are increased by using the non-formal representation outside of the existing formal representation center. The result of this study can be summarized as follows: A STEAM-based mathematics class has a positive effect on problem solving ability and self-efficacy. Therefore, it is interpreted that the application of the STEAM program focusing on mathematics accounts for education effectives.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.103-114
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• 2020

This study was conducted on Yuanming New Garden in China, which re-lighted the previously lost or damaged original space through representation from the perspective of creating traditional landscape. We looked at the composition of this place, the comparison of relevant literature and actual representation, and the characteristics of representation techniques. The results are as follows. First, TYuanming New Garden is a representation space with the motif of Yunamingyuan in Beijing. An advisory group of some 400 related experts discussed the prototype. The historicity of the real space was considered in the representation process. Second, New Yuanmingyuan garden was recreated based on the 'The Forty Scenic Views of Yuanmingyuan', and 31 of the scenic spots were created. The buildings in each precinct had a 1:1 scale response with structures that were previously constructed in Yuanmingyuan, Beijing. New Yuanmingyuan garden's way in which the main landscape is laid out around the Fuhai Lake(福海), which the landscape is drawn appeared was the same as Yuanmingyuan in Beijing. However, some of the facilities were reproduced on the basis of the 'The Forty Scenic Views of Yuanmingyuan', so they turned out to be different from what Yuanminyuan in Beijing looks like today. New Changchunyuan garden was represented around water landscape of the Western Mansins(Xiyang Lou, 西洋樓) area and the Haeakgaegum(海岳開襟), and the buildings and the facilities were reconstructed based on the 'Copper Print of Western Mansins'. Third, Yuanming New Garden made a prototype of the 'The Forty Scenic Views of Yuanmingyuan' and 'Copper Print of Western Mansins' during the process of synchronic changes in the garden. In addition, the original space and the ambiguous original space or exhibition space were clearly identified through the plant. On the other hand, due to the reenactment of buildings, the spatial composition and placeability of the original spaces of Yuanmingyuan garden and Changchunyuan garden in Beijing were not inherited, and the introduction of elements that did not match traditional landscaping spaces, and the introduction of garden elements that were not prototype and other variations for the use of tourism were found to be drawback.

• Research in Mathematical Education
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• v.17 no.1
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• pp.63-78
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• 2013

Trigonometric ratios are difficult concepts to teach and learn in middle school. One of the reasons is that the mathematical terms (sine, cosine, tangent) don't convey the idea literally. This paper deals with the understanding of a concept from the learner's standpoint, and searches the orientation of teaching that make students to have full understanding of trigonometric ratios. Such full understanding contains at least five constructs as follows: skill-algorithm, property-proof, use-application, representation-metaphor, history-culture understanding [Usiskin, Z. (2012). What does it mean to understand some mathematics? In: Proceedings of ICME12, COEX, Seoul Korea; July 8-15,2012 (pp. 502-521). Seoul, Korea: ICME-12]. Despite multi-aspects of understanding, especially, the history-culture aspect is not yet a part of the mathematics class on the trigonometric ratios. In this respect this study investigated the effect of history approach on students' understanding when the history approach focused on the mathematical terms is used to teach the concept of trigonometric ratios in Grade 9 mathematics class. As results, the experimental group obtained help in more full understanding on the trigonometric ratios through such teaching than the control group. This implies that the historical derivation of mathematical terms as well as the context of mathematical concepts should be dealt in the math class for the more full understanding of some mathematical concepts.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.2
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• pp.691-708
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• 2014

This paper formalizes a special type of social networking knowledge, which is called "workflow performer-role affiliation networking knowledge." A workflow model specifies execution sequences of the associated activities and their affiliated relationships with roles, performers, invoked-applications, and relevant data. In Particular, these affiliated relationships exhibit a stream of organizational work-sharing knowledge and utilize business process intelligence to explore resources allotting and planning knowledge concealed in the corresponding workflow model. In this paper, we particularly focus on the performer-role affiliation relationships and their implications as organizational and business process intelligence in workflow-driven organizations. We elaborate a series of theoretical formalisms and practical implementation for modeling, discovering, and visualizing workflow performer-role affiliation networking knowledge, and practical details as workflow performer-role affiliation knowledge representation, discovery, and visualization techniques. These theoretical concepts and practical algorithms are based upon information control net methodology for formally describing workflow models, and the affiliated knowledge eventually represents the various degrees of involvements and participations between a group of performers and a group of roles in a corresponding workflow model. Finally, we summarily describe the implications of the proposed affiliation networking knowledge as business process intelligence, and how worthwhile it is in discovering and visualizing the knowledge in workflow-driven organizations and enterprises that produce massively parallel interactions and large-scaled operational data collections through deploying and enacting massively parallel and large-scale workflow models.

• The Research Journal of the Costume Culture
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• v.15 no.6
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• pp.917-928
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• 2007

The purposes of this study were to investigate the hairdo attitude and hairdo involvement importances and differences depending on age. For the experimental work, questionnaires for research are prepared and asked to people who are women living in Seoul and Kyoung-Ki Do. They are collected from September to October 2006. 406 questionnaires are used in the analysis. The collected data were 'analyzed by using SPSS 12.0 software with factor analysis, Cronbach's alpha, paired T-test, and T-test. The results of this study were as follows; To analyze differences in the hairdo attitude and the hair involvement depending on different age groups, two groups were identified: one group of women aged $20{\sim}35$, and the other group of those aged $45{\sim}60$. 1. When the hairdo attitude factors were prioritized, orientations toward 'constancy' and 'consciousness of others' were found to be most critical, followed by those toward 'leader's fashion conformity' and 'distinct individuality'. When the hairdo involvement factors were prioritized, 'interests and pleasure in hairdo' were found to be most important, followed by 'symbolic representation', 'risk awareness', 'coordination of hairdo', and 'fashionableness'. 2. When difference in the hairdo attitude was analyzed, a significant difference was shown in orientations toward 'leader's fashion conformity' and 'consciousness of others'. 3. As for the hairdo involvement of the groups, a significant difference was found only in 'coordination of hairdo', signalling that the younger women put more focus on the coordination.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.491-496
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• 2019

The purpose of this study was to apply a concept map to the first-year students of radiologic science and report its effects. The concept map is a visual representation of a major concept and related linking statements. Concept maps are useful tools for students to construct and organize content they have learned. The subjects of this study were first-year grade and at one university in Chungbuk, Korea. They were divided into active and passive participant groups in the class. And they were evaluated the educational effects such as satisfaction, fidelity, learning achievement, and interest before and after using the concept map. As a result, the passive participant group significantly increased the educational effect except for satisfaction, and the active participant group significantly increased the educational effect in all variables (p<0.05). These results showed that concept mapping, which induces first-year grade students to participate in class, could be helpful in radiologic education. It is expected to be used as basic data in various radiologic educational methodology studies in the future.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1269-1286
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• 2017

This paper presents a newly developed resonance self-shielding method based on Tone's method in $APOLLO3^{(R)}$ for fast and thermal reactor calculations. The new method is based on simplified models, the narrow resonance approximation for the slowing down source and Tone's approximation for group collision probability matrix. It utilizes mathematical probability tables as quadrature formulas in calculating effective cross-sections. Numerical results for the ZPPR drawer calculations in 1,968 groups show that, in the case of the double-column fuel drawer, Tone's method gives equivalent precision to the subgroup method while markedly reducing the total number of collision probability matrix calculations and hence the central processing unit time. In the case of a single-column fuel drawer with the presence of a uranium metal material, Tone's method obtains less precise results than those of the subgroup method due to less precise heterogeneous-homogeneous equivalence. The same options are also applied to PWR UOX, MOX, and Gd cells using the SHEM 361-group library, with the objective of analyzing whether this energy mesh might be suitable for the application of this methodology to thermal systems. The numerical results show that comparable precision is reached with both Tone's and the subgroup methods, with the satisfactory representation of intrapellet spatial effects.

• The Korean Journal of Health Service Management
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• v.5 no.2
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• pp.187-197
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• 2011

The purpose of this study is to analyze factors related to the job stress experienced by call center employees at public institutions, so as to provide basic data to relieve work-related stress and enhance the job satisfaction of such employees. To promote objectivity and representation, the study was conducted by way of survey, the subjects being call center employees in 8 public institutions that operate call centers, which are located in the Busan and Seoul areas. Of the 240 surveys distributed, 196 were collected and 173 of those were used for analysis after eliminating 25 with insufficient responses. The results of this study are as follows. First, in terms of general properties, it was determined that employees with higher levels of education and families to support had greater job stress. second, in terms of job-related properties, employees who were unsatisfied with the job, HR policies, and their relationship with superiors and/or colleagues had greater job stress. In terms of the group that was satisfied compared with the group that was unsatisfied with the job, HR policies, and their relationship with superiors and/or colleagues, regular workers had less job stress than irregular workers.

• Journal of Korean Elementary Science Education
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• v.38 no.3
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• pp.375-386
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• 2019

This study explores how elementary school students construct food pyramid prediction models using scientific reasoning. Thirty small groups of sixth-grade students in the Kyoungki province (n=138) participated in this study; each small group constructed a food pyramid prediction model based on scientific reasoning, utilizing prior knowledge on topics such as biotic and abiotic factors, food chains, food webs, and food pyramid concepts. To understand the scientific reasoning applied by the students during the modeling process, three forms of qualitative data were collected and analyzed: each small group's discourse, their representation, and the researcher's field notes. Based on this data, the researcher categorized the students' model patterns into three categories and identified how the students used scientific reasoning in their model patterns. The study found that the model patterns consisted of the population number variation model, the biological and abiotic factors change model, and the equilibrium model. In the population number variation model, students used phenomenon-based reasoning and relation-based reasoning to predict variations in the number of producers and consumers. In the biotic and abiotic factors change model, students used relation-based reasoning to predict the effects on producers and consumers as well as on decomposers and abiotic factors. In the equilibrium model, students predicted that "the food pyramid would reach equilibrium," using relation-based reasoning and model-based reasoning. This study demonstrates that elementary school students can systematically elaborate on complicated ecology concepts using scientific reasoning and modeling processes.