• Nuclear Engineering and Technology
• /
• 제55권6호
• /
• pp.2112-2124
• /
• 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.

• 한국초등수학교육학회지
• /
• 제21권4호
• /
• pp.663-686
• /
• 2017

본 연구는 초등학교 3학년 학생을 대상으로 STEAM을 적용한 수학 교과 중심의 프로그램을 설계하고 현장에 적용하여 수학 교육의 융합적 접근이 학생들의 문제해결력과 자기효능감에 미치는 영향을 밝히고자 하였다. 본 연구를 위하여 D광역시 소재 C초등학교 3학년 2개 학급을 사전 검사를 통하여 실험집단과 비교집단으로 선정하여 문제해결력과 자기효능감 검사를 실시하고 결과를 분석하였다. 또한 수업결과물과 사후설문지를 분석하여 학생들의 문제해결과정에서 나타나는 융합적 사고력과 학습에 대한 긍정적인 변화정도를 파악하고자 하였다. 본 연구의 결과를 살펴보면, 문제해결력과 관련하여 두 집단 간의 검사 결과는 통계적으로 유의미한 차이를 나타내지는 않았으나 실험집단은 비교집단에 비해 수준별 고른 성취수준과 높은 평균점수를 보였다. 또한 STEAM 기반 수학 수업을 진행한 실험 집단의 자기효능감 t-검정을 실시한 결과 5% 유의수준에서 통계적으로 유의미한 결과를 보여 자기효능감에 긍정적인 영향을 미치는 것으로 나타났으며, 수업 결과물 및 소감문을 통하여 표현력의 향상과 수학적 태도의 긍정적인 변화를 확인할 수 있었다. 이를 통해 수학 교과를 중심으로 한 STEAM 프로그램 적용은 학생들의 정의적 영역에 긍정적인 영향을 주며 수학교과 수업 개선 전략으로 활용될 수 있을 것이다.

• 한국전통조경학회지
• /
• 제38권1호
• /
• pp.103-114
• /
• 2020

본 연구는 전통조경 조성 관점에서 재현을 통해 과거 소실된 또는 원형이 훼손된 공간을 재조명한 중국의 원명신원을 대상으로 조성경위, 관련 사례와 재현 실제 비교, 재현기법 상에 나타나는 특성을 살펴본 결과 다음과 같은 결론을 도출하였다. 첫째, 원명신원은 북경 원명원을 모티브로 재현된 공간으로 관련 전문가 400여 명의 자문단을 두고 상당부분 원형에 대한 논의가 진행되었고, 재현과정에서 원형공간의 역사성을 고려하였다. 둘째, 신원명원은 원명원 40경을 토대로 재현한 곳으로 원명원 40경 중 31개 경구를 조성하였으며, 각 경구 내 건조물들은 과거 북경 원명원에 조성된 건조물들과 1:1 스케일의 대응체계를 지니고 있었다. 복해를 중심으로 주요 경관이 펼쳐지는 신원명원의 경관연출 방식은 북경 원명원과 동일하게 나타났으나, 일부 시설들은 원명원 40경을 토대로 재현하여 현재 변화된 북경 원명원의 모습과는 다르게 나타났다. 신장춘원은 서양루 구역과 해악개금 일대 수경을 중심으로 재현하였으며, 건축물과 수경시설들은 서양루 20경 동판화를 토대로 당시의 모습을 재현하였다. 셋째, 원명신원의 재현특성을 살펴본 결과 정원의 통시적 변화과정 중 원명원 40경과 서양루 동판화 제작 당시의 모습을 원형으로 삼았다. 또한 식재를 통해 원형공간과 원형이 모호한 지역 또는 전시공간을 명확히 구분하였다. 반면, 건조물 중심의 재현으로 인해 원형공간인 북경 원명원 및 장춘원의 공간구성과 장소성이 계승되지 못하고, 전통조경공간과 어울리지 않는 요소의 도입, 원형과 무관한 정원요소의 도입 등 관리 편의성 증진과 관광활용을 위한 변형 등이 한계점으로 나타났다.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제17권1호
• /
• pp.63-78
• /
• 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)
• /
• 제8권2호
• /
• pp.691-708
• /
• 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.

• 복식문화연구
• /
• 제15권6호
• /
• pp.917-928
• /
• 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.

• 대한방사선기술학회지:방사선기술과학
• /
• 제42권6호
• /
• pp.491-496
• /
• 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
• /
• 제49권6호
• /
• pp.1269-1286
• /
• 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.

• 보건의료산업학회지
• /
• 제5권2호
• /
• pp.187-197
• /
• 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.

• 한국초등과학교육학회지:초등과학교육
• /
• 제38권3호
• /
• pp.375-386
• /
• 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.