• Journal of the KSME
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• v.30 no.3
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• pp.258-266
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• 1990

그간 화인세라믹에 대한 기대는 점점 더해졌으며 신소재붐의 최고의 지위를 확보했다고도 할 수 있다. 더욱이 최근에 있어서 실소온도이상의 높은 임계온도를 갖는 세라믹 초전도체가 발견되 었으며 새로운 재료의 개발은 신기술을 창성할 뿐만 아니라 산업 및 국민생활에도 변혁을 가져올 가능성이 확인되어 신소재로의 기대가 더한층 높아졌다. 각종 기술부품등으로서의 화인세라믹은 자동차용 엔진연구를 시작으로 발전되어 최근에는 점차로 그 제품개발의 단계에 도달하고 있다. 이와 같이 하나의 소재가, 말하자면 공업재료로서 정착하기에는 엄격한 개발경쟁과 그에 따른 시간이 요하게 된다. 본 글에서는 엔지니어링 세라믹의 개발경과를 살펴보고 최근의 동향 및 응용의 현상에 관하여 기술하고자 한다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.29-29
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• 2010

건물일체형 태양전지 (BIPV; building integrated photovoltaics)나 야외 태양광 발전 차양 등의 태양광 발전에는 기존의 유리 기판 태양전지보다 가볍고 유연한 flexible 박막 태양전지가 설치하고 운영하는데 적합하다. 이러한 flexible 박막 태양전지는 자동차나 휴대기기의 전원이나 배터리의 충전기기로도 쓰이며 그 수요가 증가 추세에 있다. 특히, flexible Cu(In, Ga)$Se_2$(CIGS) 박막 태양전지는 기존의 flexible 실리콘 박막 태양전지보다 효율이 높아서 앞으로 성장 잠재력이 매우 높다. 세계적으로도 많은 기업이 상용화를 추진하고 있으며, 2007년부터 시장에 진입하고 있다. 그러나 현재의 flexible CIGS 박막 태양전지는 유리 기판 CIGS 박막 태양전지보다 효율이 낮고 패키지를 유리에서 플라스틱으로 대체하기 때문에 수명이 짧다. 또한, 아직도 완전한 양산 체제로 전환이 이루어지지 않았기 때문에 해결해야 할 문제점이 많이 있다. Flexible 기판으로는 스테인리스 스틸이나 폴리머 기판이 사용되는데, 유리 기판에 비해 저가 태양전지를 제조할 수 있을 뿐만 아니라 roll-to-roll 공정을 적용할 수 있어 가격 경쟁력을 확보할 수 있다. 특히, 금속 유연기판을 사용할 경우, 유리 기판에 비해 상대적으로 고온 공정이 가능한 장점이 있다. 그러나, 금속 기판을 사용할 경우 해결해야 할 두 가지 이슈가 있다. 첫째, CIGS 흡수층 형성에 도움을 주는 Na의 공급 문제이다. 유리 기판의 경우 기판에 포함되어 있는 Na이 확산을 통해 공급되지만, 금속 기판의 경우 별도의 Na 공급 방법을 고려해야 한다. 둘째, 불순물 확산 방지막 및 전기 절연층으로 사용되는 유전체 박막의 문제이다. 현재 다양한 금속 산화물 유전체 박막을 사용한 연구가 진행되고 있다. 본 논문에서는 flexible CIGS 박막 태양전지의 기술적 이슈 및 현재 연구 현황을 살펴보고, 스테인리스 스틸 기판을 이용한 CIGS 박막 태양전지에서 유전체 확산 방지막에 따른 특성을 비교하고자 한다. 스테인리스 스틸 기판의 불순물로부터의 확산을 방지하기 위하여 두 종류(intrinsic ZnO와 SiOx)의 유전체 박막을 각각 Na가 도핑된 Mo층과 스테인리스 스틸 기판 사이에 삽입하여 소자를 제작하였다. 확산 방지막이 없는 경우, SiOx층을 사용한 경우, 그리고 intrinsic ZnO 층을 사용한 경우에, 효율은 각각 7.47, 11.64, and 13.95%로 나타났다. 셀의 크기는 $0.47\;cm^2$이고, 반사방지막은 사용하지 않았다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.58-65
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• 2021

In this study, as a method to increase the recycling of circulating fluidized bed combustion ash(CFBCA), CFBCA was utilized to produce autoclave aerated concrete product since CFBCA contains quicklime and calcium sulfate components that are required for the manufacture of autoclave aerated concrete. Successful achievement of such objective will bring cost reduction with high value addition, saving of natural resources, and the reduction of environmental load. Various mixing designs were designed to evaluate the properties of autoclave aerated concrete made of CFBCA. Based on series of experimental program, prototypes mix design for factory manufacturing was obtained. According to the experimental results, it was confirmed that gypsum can be replaced with CFBCA through the method of pre-treating the CFBCA as a slurry. It was possible to produce competitive autoclave aerated concrete products using CFBCA.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.282-293
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• 2010

Currently, due to the rapid growth of Internet businesses, competition is deepening even in Internet portal markets. In markets where competition is severe, companies can no longer hold a competitive advantage if they cannot deliver their own distinguished, unique images to customers. Therefore, this research planned to establish distinguished positioning strategies by comparing competition relationships among portals which go through building positioning maps and understanding the evaluation attributes and ideal points of internal portal images preferred by segmented customer groups. College students who are heavy users of the Internet were selected as research subjects, and they were led to make an evaluation of the image of Internet portals they mainly use. The analysis result showed that attributes distinguished the most among portals were entertainment, additional service, and convenience while the attribute distinguished the least was customer service. Moreover, understanding of preference and ideal points regarding portals also showed significant differences by segmented groups. Such research results are expected to become meaningful raw data in regards to building distinguished market segment strategies in Internet portal markets.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.205-214
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• 2017

The purpose of this study is to identify the perceptions of organizational members in new product development. This study suggested the successful new product development through the awareness among CEO and other members of the recognition of various factors that appear in the process of new product development by technical-oriented venture companies. Other members were more competitive in the technical area than CEO and were recognized as important strategic factors. As perceived market environment, perception of macro-environment is perceived by other members to be sensitive technical environment and economic factors, and law part is recognized as important. Recognition in a micro-environment has been associated with higher perceptions of employees and competitors, and siliar perceptions of marketing strategy and supplier relationships. This study suggested strategies for successful new product development by reducing the difference of perception between communication and environment of new products by SEMs and venture companies.

• Convergence Security Journal
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• v.12 no.3
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• pp.123-129
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• 2012

Due to the high digital technology, various devices such as TV, PC, smartphone, and pad computer are connected to each other using internet and under the circumstance internet services of which the running platforms are mainly PC become "N-screenlized" by extending their service platform to non-PC devices. As a digital TV has outstanding features of being the most influential device in the living room and having the wide spectrum of users, several internet services has been ported on the digital TV platform (in the form of data services) in order to enhance their brand powers. Most of the services, however, failed to get a satisfactory results as the data services are defeated by the broadcasting contents in the competition for the viewer's interests. In the paper, the design guidelines that make data services not to compete with the broadcasting contents are proposed and a prototype of a data service that accommodates the guidelines is introduced. The prototype, called "TV ideal-type world-cup", does not disturb a viewer's watching broadcast contents and channel-changing behavior while it is running and its service flow is designed for a viewer to achieve the goal of service in a few minutes so that the viewer can enjoy the service in a commercial period.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.1
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• pp.257-284
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• 2020

The purpose of this study is to derive differentiation strategy through strategy competition analysis on public libraries in order to enhance the competitiveness and efficiency of libraries. To that end, this study conducted a status analysis, management resources analysis, external and internal environment analysis on four public libraries located in Jung-gu, Incheon to identify the situation of strategy competition, and conducted a competitor analysis, customer segment analysis, and customer value analysis of four public libraries through various library related statistical data, national library operation evaluation data, library user satisfaction surveys, and interview with chief librarian and senior librarians. As the result, this study suggests three differentiation strategies by library. First of all, the four public libraries need to provide customized services targeting different target users within the region. Secondly, public libraries need to develop active library services that directly visit passive users, who are information have-nots, considering geographical accessibility and the composition of the population in the region. Last, public libraries should form a cultural community that cooperate with the local community and develop various programs that reflect the identity of the region.

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.69-81
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• 2000

The vegetation structure of Abies holophylla forest was analyzed to provide the information for conservation of Abies holophylla forest at Wol-jong Temple in Mt. Odae national park, southern Korea. The layer structure of Abies holophylla forest was consists of tree layer(2 species), subtree layer(20 species), shrub layer(46 species) and herb layer(87 species), The importance value of Abies holophylla was the highest one 34.09%, and those of Acer pseudo-sieboldianum. Acer barbinerve, Philadelphus schrenckii. Isodon excisus, Acer triflorum, Staphylea bumalda, Carex humilis, Isodon japonicus, Acer mono and Actinidia polygama were 23.07%, 14.44%, 10.72%, 8.49%, 7.80%, 7.65%, 6.79%, 5.76%, 5.47% and 5.41%, respectively, Especially, when predicting succession in Abies holophylla forest, such seedlings were not formed and succession was governed by competition of Acer species, Quercus species and Tilia species of subtree and shrub layer.

• Journal of Life Science
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• v.21 no.1
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• pp.127-133
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• 2011

${\beta}$-Galactosidase was immobilized on chitosan bead by covalent bonding using glutaraldehyde. The characteristics of the immobilized enzyme were investigated. Maximum immobilization yield of 75% was obtained on chitosan bead. Optimum pH and temperature for the immobilized enzyme was 7.0 and $50^{\circ}C$, respectively. The immobilized enzyme showed a broader range of pH and temperature compared to a free one. A mathematical model for the operation of the immobilized enzyme in a packed-bed reactor was established and solved numerically. Under different inlet lactose concentrations and feed flow rate conditions, lactose conversion was measured in a packed-bed reactor. The experimental results of continuous operation in a packed-bed reactor were compared to theoretic results using Michaelis-Menten kinetics with competitive product inhibition and external mass transfer resistance. The model predicted the experimental data with errors less than 5%. Process optimization of continuous operation in a packed-bed reactor was also conducted. In a recirculation packed-bed operation, conversion of lactose was 97% in 3 hours. In a continuous packed-bed operation, the effect of flow rate and initial lactose concentration was investigated. Increasing flow rates and initial lactose concentration decreased the conversion of substrate.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.103-115
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• 2016

The 106 buildings of 200 meters' height or greater were completed around the world in 2015 (CTBUH, The Council on Tall Buildings and Urban Habitat). They beat every previous year on record, including the previous record high of 99 completions in 2014. This brings the total number of 200-meter-plus buildings in the world to 1,040, exceeding 1,000 for the first time in history and marking a 392% increase from the year 2000, when only 265 existed. South Korea recorded three completions during 2015 - improving slightly over 2014, in which it had one. This study focused on the fact that high-rise building development project risks have not reduced in Korea in spite of numerous studies and measures. And it attempted to examine whether existing studies and measures have been presented on the basis of the accurate analysis of existing studies and measures and classify and analyze the characteristics of each phase' s risk factors in the hope that its results would be one reference point as to the measure to prevent high-rise building development project risks in the future. A high-rise building development project is the high risk project as compared with the low-rise project. Because a high-rise development project takes long and is very sensitive to the changing environment. Therefore, in order to succeed the project it becomes necessary to effectively manage the risk involved in the process of the high-rise building development project. The result of this study can be used as the guideline to make the risk management system for the high-rise development project.