• Elastomers and Composites
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• 제53권3호
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• pp.175-180
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• 2018

Solution-styrene-butadiene rubber (SSBR) composites were manufactured using four kinds of fillers: silica-silane coated carbon black (SC-CB) hybrid, starch-SC-CB hybrid, pure silica, and pure starch. The influence of filler type on the mechanical properties of the rubber matrix was studied in this work. SC-CB was prepared by silane-graft-coating using vinyl triethoxy silane and carbon black, which enhanced the dispersion effect between the rubber matrix and the filler, and improved the mechanical properties of the compounds. The morphology of the composites was observed by field-emission scanning electron microscopy (FE-SEM). The thermal decomposition behavior of the composites was determined by thermogravimetric analysis (TGA), and the crosslinking behavior of the composites was tested using a rubber process analyzer (RPA). The hardness, tensile strength, swelling ratio, and gas transmittance rate of the composites were evaluated according to ASTM. The test results revealed that with the addition of SC-CB, the hybrid fillers, especially those blended with silica, showed a better reinforcement effect, the highest hardness and tensile strength, and stable thermal decomposition behavior. This implies that the silica-SC-CB hybrid filler has a notable mechanical reinforcement effect on the SSBR matrix. Because of self-crosslinking during its synthesis, the starch-SC-CB hybrid filler produced the most dense matrix, which improved the anti-gas transmittance property. The composites with the hybrid fillers had better anti-swelling properties as compared to the neat SSBR composite, which was due to the hydrophilicity of silica and starch.

• 컴퓨터교육학회논문지
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• 제6권1호
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• pp.109-120
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• 2003

오늘날 웹 활용이 본격적인 대중화 시대로 접어들게 되면서 교육현장에서도 다양한 교육방법이 연구, 개발되어 WBI 학습, 웹기반 CAI, 원격강의 등 웹을 기반으로 하는 가상교육이 활발히 진행되고 있다. 웹기반 교육이 교실수업에 비해 가지는 장점을 최대한 살려서 현실성 있고 효율적인 교육의 효과를 얻으려면 학습자의 능력과 관심, 흥미, 적성 등을 고려한 웹기반 수준별 수업 모형 개발이 요구된다. 본 논문에서는 제7차 교육과정에서 실시되는 단계형 수준별 교육과정에서 진급형 수업모형과 심화 보충형 수업모형을 웹기반 수업을 위해 혼합한 혼합형 수준별 수업모형으로 제시하고 구현한다. 또한, 모형의 비교를 위하여 이를 실업계고등학교의 전산회계 교과에 적용한다. 웹기반 수업을 하기 위해서 인터넷이 가능한 학교 전산실을 이용하며 100분 동안 학생들이 자율적으로 웹기반 학습을 하도록 한다. 수업 적용을 하고 설문 조사를 실시하여 웹기반 수업에 대한 효과와 수업모형의 학업성취도에 미치는 영향을 분석 후 결과를 제시한다.

• KEPCO Journal on Electric Power and Energy
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• 제2권1호
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• pp.49-54
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• 2016

현재 대부분의 도서지역에서는 태양광발전을 효율적으로 운용하기 위하여 대용량 연축전지가 많이 사용되고 있지만, 풍력발전의 도입, 축전지 교체로 인하여 리튬이온전지의 도입이 증가하고 있다. 따라서 본 논문에서는 기존에 많이 보급되어 사용되고 있는 연축전지와 리튬이온전지의 장점을 최대한 활용하기 위하여, 연축전지와 리튬이온전지용 하이브리드 ESS의 최적 운용평가를 할 수 있는 알고리즘을 제시하였다. 상기의 알고리즘을 이용하여 시뮬레이션을 수행한 결과, 각 전지의 도입비용과 운용비용이 최소화 되는 운용조건에서 최적구성비를 산출하였다. 이에 따라 본 논문에서 제안한 하이브리드 ESS의 최적구성 알고리즘에 대한 유용성을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1675-1680
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• 2014

A peroxopolyoxotungsten-based ionic hybrid was synthesized by anion-change of peroxopolyoxometalate (POM) $PW_4O{_{24}}^{3-}$ with dicationic long-chain alkyl imidazolium ionic liquids. The characterization was conducted by FT-IR, TGA, $^1H$-NMR and CHN Elemental analyses. Its catalytic performance was evaluated by the epoxidation of soybean oil with $H_2O_2$ under solvent-free condition, including testing of organic cations influence, catalytic reusability and reaction conditions. The catalyst was proved to be a highly efficient recyclable catalyst for epoxidation of various vegetable oils with $H_2O_2$, showing high $H_2O_2$ utilization efficiency, high catalytic activity, convenient recovery and good reuse ability.

• Mycobiology
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• 제31권3호
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• pp.151-156
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• 2003

Two fungal isolates obtained from roots of Cymbidium goeriingii in Jeju island were confirmed to be symbiotic with orchid plantlets, and were compared with other orchid mycorrhizal(OM) fungi previously isolated. The two isolates differed in their peloton structures formed in the roots of Cymbidium kanran hybrid 'Chungsu' and in responses of orchid plant. These two isolates differed from the additionally tested OM fungi in some features, and from root damaging species of Rhizoctonia and Fusarium as based on cluster analysis after PCR-RAPD with the primers, Bioneer-28 and OPO-2. With this simple and fast technique, it was possible to distinguish OM fungi from the plant root pathogenic fungi based on calculation of their polymorphic bands. This technique can therefore be helpful to distinguish the OM fungi from the root pathogens. Particularly, the new isolates are considered as new resource of symbiotic fungi for horticultural industries.

• Carbon letters
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• 제27권
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• pp.72-80
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• 2018

In the present work, a comparative study of the mechanical behavior of two series of elastomeric composites, based on carboxylated styrene butadiene rubber (X-SBR) and reinforced with rice bran carbon (RBC) and graphite, is reported. Hybrid composites of X-SBR filled with RBC-graphite were also investigated in terms of the cure characteristics, hardness, tensile properties, abrasion resistance, and swelling. It was observed that the cure times decreased with the incorporation of a carbon filler whereas the torque difference, tensile strength, tensile modulus, hardness, and swelling resistance increased compared to the neat X-SBR revealing a favorable characteristic of crosslinking. Dynamic rheological analysis showed that the G' values of the composites, upon the addition of RBC-graphite, were changed to some extent. This demonstrates that the presence of a strongly developed network of fillers will ensure a reinforcing characteristic in a polymer matrix.

• 한국간호교육학회지
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• 제29권1호
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• pp.27-40
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• 2023

Purpose: The study aimed to examine the concept and attributes of the quality of clinical nursing education for new graduate nurses. Methods: This study adopted a hybrid model introduced by Schwartz-Barcott and Kim. In the theoretical stage, the meaning and attributes of the quality of clinical nursing education for new graduate nurses were determined by analyzing eight articles. In the fieldwork stage, data were collected using semi-structured interviews with five new graduate nurses and seven experienced nurses. The data were analyzed by qualitative content analysis methods developed by Elo and Kyngӓs. In the final analysis, a final result was arrived at comparing, contrasting, and integrating the attributes of the concepts derived in the theoretical and field-work stages. Results: The quality of clinical nursing education for new graduate nurses was identified as excellence or the standard of education for new graduate nurses that would support them in adapting to clinical settings and transitioning to professional nurses. The attributes of the quality of clinical nursing education were founded to possess three dimensions, six categories, and 18 attributes. The multidimensional attributes of the quality of clinical nursing education for new graduate nurses were confirmed as education resources, design, method, content, evaluation, interaction, and outcome under the three dimensions of input, process, and output. Conclusion: The concept and nature of the quality of clinical nursing education observed in this study can be utilized as a basis for the future development, evaluation, and improvement of clinical nursing education for new graduate nurses in healthcare organizations.

• 한국컴퓨터교육학회 학술대회
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• 한국컴퓨터교육학회 2017년도 하계학술대회
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• pp.57-59
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• 2017

대화 시스템(dialogue system)은 텍스트나 음성을 통해 다양한 분야에서 특정한 목적을 수행할 수 있는 시스템이다. 대화 시스템을 구현하기 위한 방법으로 인공 신경망(neural network)을 기반으로한 end-to-end learning 방식이 제안되었다. End-to-end learning 방식을 이용한 식당 예약 시스템 모델의 학습을 위해 페이스북은 영어로 이루어진 식당 예약에 관련된 학습 대화 데이터셋(The 6 dialog bAbI tasks)을 구축하였다. 하지만 end-to-end learning 방식의 학습은 많은 학습 데이터가 필요하다는 단점이 존재하는데, 액션 템플릿(action template)의 정의를 통해 도메인 지식을 표현함으로써 일반적인 end-to-end learning 방식보다 적은 학습량으로 좋은 성능의 모델을 학습할 수 있는 Hybrid Code Network 구조를 제안한 연구가 있다. 본 논문에서는 Hybrid Code Network 구조를 이용하여 한국어 식당 예약 시스템을 구축할 수 있는 방법을 제안하고, 한국어로 이루어진 식당 예약에 관련한 학습 대화 데이터를 구축하는 방법을 제안한다.

• 한국항행학회논문지
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• 제15권2호
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• pp.281-286
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• 2011

데이터 정렬은 현대 사회에 존재하는 수많은 디지털 데이터에 대한 중요한 가공 작업 중의 하나이지만, 데이터가 방대할수록 정렬 과정 자체도 많은 연산시간을 소비한다. 본 논문에서 데이터 배열을 분할하여 PC에 있는 CPU와 GPU에서 각각 동시에 정렬을 수행하는 혼합 정렬 알고리즘을 제안하였다. 각 장치의 처리 성능을 바탕으로 가장 효율적인 배열의 분할 범위를 결정하고 각각 분할된 영역을 CPU와 GPU에서 동시에 정렬함으로써 전체 정렬 시간을 단축시켰다. 실험결과에서 알 수 있듯 혼합 정렬이 GPU만 활용한 정렬보다 8%이상 정렬 수행 속도를 향상시켰다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제26권3호
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• pp.111-131
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• 2019

We introduce (CLRg) property for hybrid pair $F:X{\times}X{\rightarrow}2^X$ and $g:X{\rightarrow}X$. We also introduce joint common limit range (JCLR) property for two hybrid pairs $F,G:X{\times}X{\rightarrow}2^X$ and $f,g:X{\rightarrow}X$. We also establish some common coupled fixed point theorems for hybrid pair of mappings under generalized (${\psi},{\theta},{\varphi}$)-contraction on a noncomplete metric space, which is not partially ordered. It is to be noted that to find coupled coincidence point, we do not employ the condition of continuity of any mapping involved therein. As an application, we study the existence and uniqueness of the solution to an integral equation. We also give an example to demonstrate the degree of validity of our hypothesis. The results we obtain generalize, extend and improve several recent results in the existing literature.