• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2011-2018
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• 2024

Since RF breakdown is one of the primary limitations to improving the performances of RF accelerators, extensive efforts have been dedicated to locating the breakdowns. However, most existing methods rely on specialized techniques, resulting in high financial burdens. Although the method based on transient response of transmission line (TL) is suitable for facilities with sporadic recoverable breakdowns, practical operations are susceptible to notable errors. This study revisits the fundamental theories of lossless TL and investigates the wave process to understand the characteristics of the reversed pulse induced by the breakdowns. By utilizing steadystate response of the TL and employing phasor method, we derive analytical formulas to determine the exact location of breakdowns within the faulty cell for constant-gradient TW accelerator. Furthermore, the derived formulas demonstrate their independence from RF phase, thereby distinguishing them from traditional phasebased methods. Additionally, experimental validations are conducted at the HUST injector, and the results confirm the consistency of the analysis. Thus, the proposed method represents a promising improvement over the TL-based approaches and serves as a valuable complement to current techniques. Importantly, this method demonstrates particular advantages for constructed TW accelerators seeking to achieve a balance among high performance, low costs, and compact layouts.

• 한국조리학회지
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• 제17권4호
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• pp.1-12
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• 2011

본 연구는 조리전공 고등학생을 대상으로 교육 서비스가 학교만족도에 미치는 영향을 분석하여 학교만족도와 추천의도를 높이기 위한 방안을 모색하고자 하였다. 선행연구를 토대로 교육서비스 요인을 도출하였고 총282개의 표본을 대상으로 자기기입식 설문을 실시하였다. 수집된 설문 데이터는 SPSS 12.0을 이용하여 빈도분석, 요인분석, 신뢰도 분석, 회귀분석 동의 분석 방법으로 검증하였다. 분석 결과는 다음과 같다. 회귀분석을 통해 '전문교과서비스'와 '시설서비스'가 학교만족도에 긍정적인 (+)영향을 주며 학교만족도는 추천의도를 향상시키는 것으로 나타났다. 이러한 분석 결과를 토대로 교육서비스의 수요자인 조리 전공 고등학생들의 학교만족도를 높이기 위해서는 내실 있는 전문교과 운영과 시설투자에 관한 재정적 지원이 필요함을 확인하였다. 한계점과 추후 연구 방향에 대해서도 논의하였다.

• 한국컴퓨터정보학회논문지
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• 제27권3호
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• pp.127-135
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• 2022

이 연구의 목적은 중등체육교원 임용고사 육상실기평가에 대한 예비체육교사의 인식을 탐색하는데 있다. 이를 위해 인간 내면의 감정, 의견, 인식 등을 탐색할 수 있는 Q방법론을 활용하였다. 분석결과 3가지 유형이 탐색되었고, 각 유형은 전문시설지원요구형과 전문기술지도요구형 그리고 평가방법개선요구형으로 명명되었다. 결론으로, 중등체육교원 임용고사 육상실기평가를 준비하는데 있어 예비체육교사들은 전문시설의 지원과 전문기술을 지도받을 수 있는 기회의 제공 그리고 평가 방법과 절차에 대한 구체적인 사전 안내 등을 희망하는 것으로 해석되었다.

• Human Ecology Research
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• 제55권5호
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• pp.539-553
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• 2017

This study explored the organization of high school Home Economics (HE) selective curriculum for the Fourth Industrial Revolution. We critically review the change process of HE curriculum as well as problems based on the understanding of the Fourth Industrial Revolution. The results were as follows. First, regarding the characteristic consistently shown in the revision process of high school curriculum, the huge increase of the number of subject organized resulted from the intensification of the selective-centered curriculum strengthening the choice for school and students. However, HE was reduced to some 'Technology-Home Economics' subject and a single subject 'HE Science' as a selective subject was subsequently combined with Technology after the $7^{th}$ curriculum period. Consequently, HE hard to organize the career-focused curriculum, emphasized by the revised 2015 curriculum due to the insufficient number of subjects. Second, the choice of HE in high school curriculum should be expanded as measures to organize the HE curriculum of high school to cope with changes that result from the Fourth Industrial Revolution. For the operation of the career-focused curriculum, career selective subjects and specialized subjects should be more diversely established. In accordance with changes in a future society that results from the Fourth Industrial Revolution, the HE education community should be prepared in advance to be organized as a selective subject when revising a subsequent curriculum, by newly establishing subjects necessary to students through collective intelligence and deliberation with pedagogists and scholars for subject content as well as by producing/getting approval from government-recognized textbooks.

• 대한지구과학교육학회지
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• 제17권1호
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• pp.70-85
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• 2024

이 연구의 목적은 기후 행동이 참여자에게 미치는 영향은 무엇인지, 고등학교에서 기후 행동 교육이 어려운 이유는 무엇인지를 알아보는 것이었다. 이를 위해 기본적 질적 연구(basic qualitative research) 방법을 택하였으며 연구참여자는 활동 당시의 중학생 5명이다. 연구 결과는 다음과 같다. 중학생 때의 기후 행동으로 참여자의 진로는 구체적으로 변하였고 기후 소양은 함양되었다. 그리고 고등학교에서 기후 행동 교육은 충분하지 않았다. 기후 행동 교육을 하는 환경 과목은 많은 학생의 선택을 받지 못하여 개설이 어려웠으며 대학 입시에 대한 부담으로 창의적 체험활동 시간에 기후 행동 교육을 하는 것은 비현실적이었다. 이 연구의 논의점은 다음과 같다. 기후 행동은 진로를 구체화하고 기후 소양을 함양하는 데 일조하기 때문에 중학생에게 장려할 필요가 있다. 또한 기후 행동은 지속성이 중요하기 때문에, 기후 소양을 꾸준히 유지할 수 있도록 초·중·고등학교의 교육과정에 기후 행동 교육을 전문적으로 할 수 있는 과목을 개설할 필요가 있다.

• 한국초등과학교육학회지:초등과학교육
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• 제33권4호
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• pp.646-654
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• 2014

The aim of this study was to investigate the patterns of the elementary school students' interests to animals and plants based on affinity toward animals and plants, and curiosity about animals and plants by using a cluster analysis. In addition, the differences of the big five personality traits by the identified clusters was examined. A total number of 411 elementary school students participated in the study. The students were clustered into four distinct interest groups with respect to the level of interests to animals and plants. Cluster 1 'Developed Interest to Organisms group' showed high levels in the interest to both animals and plants. Cluster 2 'Developed Interest to Animals group' showed high interest to animals and relatively low interest to plants whereas cluster 3 'Developed Interest to Plants group' showed high interest to plants and relatively low interest to animals. Lastly, cluster 4 were identified as 'Lack of Interest to Organisms group' by showing low levels of interest to both animals and plants. The four identified groups also showed different distributions of students according to gender and school year. These results support gender difference in the interest to animals and plants and suggest the decreased and specialized interest with school year. The Big Five personality traits excluding neuroticism were positively related with the interest to organisms and the identified groups showed significant differences in the traits. These findings indicate that agreeableness, conscientiousness, extraversion, and openness can be significant predictors of the interests to animals and plants.

• Journal of Communications and Networks
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• 제14권5호
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• pp.546-553
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• 2012

Compact routing intends to achieve good tradeoff between the routing path length and the memory overhead, and is recently considered as a main alternative to overcome the fundamental scaling problems of the Internet routing system. Plenty of studies have been conducted on compact routing, and quite a few universal compact routing schemes have been designed for arbitrary network topologies. However, it is generally believed that specialized compact routing schemes for peculiar network topologies can have better performance than universal ones. Studies on complex networks have uncovered that most real-world networks exhibit power-law degree distributions, i.e., a few nodes have very high degrees while many other nodes have low degrees. High-degree nodes play the crucial role of hubs in communication and inter-networking. Based on this fact, we propose two highest-degree landmark based compact routing schemes, namely HDLR and $HDLR^+$. Theoretical analysis on random power-law graphs shows that the two schemes can achieve better space-stretch trade-offs than previous compact routing schemes. Simulations conducted on random power-law graphs and real-world AS-level Internet graph validate the effectiveness of our schemes.

• 대한금속재료학회지
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• 제48권4호
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• pp.369-375
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• 2010

Ti-6Al-4V ELI alloy, which is commonly used as a biomaterial, is associated with a high elastic modulus and poor biocompatibility. This alloy presents a variety of problems on several areas. Therefore, the development of good non-toxic biocompatible biomaterials with a low elastic modulus is necessary. Particularly, hydroxyapatite (HA) is an attractive material for human tissue implantation. This material is widely used as artificial bone due to its good biocompatibility and similar composition to human bone. Many scientists have studied the fabrication of HA as a biomaterial. However, applications of bulk HA compact are hindered by the low strength of HA when it is sintered. Therefore, HA has been coated on Ti or Ti alloy to facilitate good bonding between tissue and the HA surface. However, there are many problems when doing this, such as the low bonding strength between HA and Ti due to the different thermal expansion coefficients and mechanical properties. In this study, a Ti-HA composite with a porous surface was successfully fabricated by pulse current activated sintering (PCAS) and a subsequent leaching process.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.1-8
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• 2011

Techniques to evaluate gene expression profiling, such as sufficiently sensitive cDNA microarrays or real-time quantitative PCR, are efficient methods for monitoring human pluripotent stem cell (hESC/iPSC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turn-around time, and the involvement of highly specialized technical expertise. Hence, there is an urgency of rapid, cost-effective, robust, yet sensitive method development for routine screening of hESCs/hiPSCs. A critical requirement in hESC/hiPSC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all three germ layers, including ectoderm, mesoderm, and endoderm. To quantify the modulation of gene expression in hESCs/hiPSC during their propagation, expansion, and differentiation via embryoid body (EB) formation, we developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR platform technology. Among the 9 gene primers tested, 5 were pluripotent markers comprising set 1, and 3 lineage-specific markers were combined as set 2, respectively. We found that these 2 sets were not only effective in determining the relative differentiation in hESCs/hiPSCs, but were easily reproducible. In this study, we used the hES/hiPS cell lines to standardize the technique. This multiplex RT-PCR assay is flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC/hiPSC lines during routine maintenance and directed differentiation.

• 한국지구과학회지
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• 제26권1호
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• pp.30-40
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• 2005

본 연구의 목적은 과학영재학교 재학생을 대상으로 과학영재학교의 교수활동에 관한 학생의 인식을 밝히고 과학과 실험수업의 실제 분석하는데 있다. 이를 위하여 과학과 교육과정 편제 및 운영, 교수$\cdot$학습방법 평가 방법에 관한 설문 결과와 과학과 실험수업에서의 언어적 상호작용 유형을 분석하였다. 과학영재학교 교육과정 편제 및 운영에 대한 학생들의 인식을 조사한 결과, 심화선택과목의 학점 비중을 더 높여야 한다는 의견과 보통교과의 학점을 줄이고 수학 및 과학 교과의 학점을 늘려야 한다는 의견이 상대적으로 높게 나타났다. 또한 과학영재학교 과학과 수업시사간에 주로 사용되는 수업방법으로는 강의나 설명, 조별수업, 토론이 대다수를 차지하였고 학생들이 선호하는 수업방법으로는 강의나 설명, 토론 외에도 탐구학습, 개인연구, 문제해결학습 등 다양하게 나타났다. 그리고 학생들이 선호하는 평가방법은 지필 평가와 보고서평가, 실험 평가의 순으로 나타났다. 과학영재학교 과학실험 수업에서 상호작용 유형을 분석한 결과, 교사 질문의 수준에 따라 교사-학생 상호작용 유형이 다르게 나타났고, 실험과정 중에는 학생-학생 상호작용에 의해 탐구활동이 활성화되었다.