• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.4.2-4.2
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• 2010

최근 열전달율을 획기적으로 향상시킬 수 있는 고 열전도성 나노유체가 주목을 받고 있다. 고 열전도성 나노유체는 액상보다 열전도도가 수백~수만 배 높은 고상의 금속 또는 비금속 나노입자를 물이나 오일 등에 미량 균일하게 분산시킴으로써 기존의 유체가 가지지 못한 높은 열전도율과 분산안정성을 갖는 기능성유체를 말한다. 고 열전도성 나노유체는 기존 냉각시스템에서 냉각유체만 교체할 경우에도 열전달 효율을 20% 이상 향상시킬 수 있는 저비용 고효율작동 유체이다. 이 나노유체는 발전설비, 공조설비, 에너지 산업, 석유화학, 화학공업, 제철산업, 가정용 냉난방설비, 자동차 등 산업 전 분야의 열교환시스템에 활용이 가능하다. 따라서 고 열전도성 나노유체는 종래 열효율의 한계를 돌파할 수 있는 에너지 이용 효율 향상 기술의 패러다임을 바꿀 혁신적인 신소재로 여겨지고 있다. 그러나 현재까지 개발된 나노유체는 초기 열전도 특성은 우수하나 장기간 분산안정성이 확보되지 않아 시간이 경과함에 따라 열전도도가 점점 감소하는 경향을 보인다. 또한 탄소나노튜브를 분산한 나노유체의 경우와 같이 유체의 점도가 크게 증가하여 실제 산업에 적용 시 커다란 동력손실을 초래할 수 있으며 열교환시스템에 파울링이 발생할 소지가 크다. 이러한 문제점을 해결하기 위해서는 나노유체에서 열전달이 일어나는 메커니즘이 규명되어야 하지만 아직 명확한 이론이나 가설이 정립되어 있지 않다. 이 논문에서는 나노유체가 높은 열전도율을 보이는 현상을 설명할 수 있는 몇 가지 이론을 살펴 보고 지금까지 개발된 안정성이 아주 높은 나노유체의 열전도 특성을 비교 분석하여 획기적인 열전도성 나노유체 개발 가능성을 살펴보고자 한다. 이를 위해 나노입자의 조성, 유체 내 농도 및 자기장 등이 나노유체의 열전도율에 미치는 영향을 연구하였다.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.319-321
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• 2007

사회에서 지대한 관심과 논란의 대상이 되고 있는 한전의 고압전력 설비 중 송전선에서 발생하는 ELF(Extremely Low Frequency)전자계 저감을 위한 사회적비용의 계량화에 관한 연구를 하였다. 송전선로에서 발생되는 극저주파 전자계와 토지가격 사이의 관계론 규명하는 본 연구는 분서의 틀로서 극저주파 전자계 저감을 위한 다양한 기법에 대해서 제시하였다. 또한 다양한 황경가치 평가기법을 비교 분석한 결과, 헤도닉가격법이 가장 적정한 것으로 판단되어 이 분석법을 본 연구의 주된 분석도구로 삼고자 한다. 최근 환경질의 가치평가 기법으로 가장 광범위하게 사용되고 있는 기법중 하나인 헤도닉가격법은 기본적으로 주택, 토시 같은 재화는 그 자체가 가진 물리적 특성뿐만 아니라 외적인 환경 등 다양한 특성으로 이루어진 차별적 재화(differentiated product)라는 헤도닉가설(hedonic hypothesis)을 전제로 한다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.427-428
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• 2022

최근 대규모 항만 건설 및 기존 부두 리모델링과 같은 해안 공간 구조물 확충사업이 활발하게 진행되고 있으며 항만 구조물 거동 장기계측을 위한 센서에 대한 관심도 높아지고 있다. 기존의 항만에 적용한 전기식 센서들은 수개월 정도 단기간의 구조물 거동 측정은 가능하지만 수년 이상의 장기계측 시 염수분에 의한 부식 및 내구성에 취약하기 때문에 원활한 측정에 한계점이 있고 센서 설치를 위한 항만 외곽지역 구조물과 육상전원공급설비 배전반 사이의 거리로 인하여 긴 연장의 횡단로 가설전선 보호대 등을 설치해야 하는 어려움이 있다. 따라서, 본 연구에서는 항만 구조물 거동 장기계측을 위해 기존 전기식 센서들의 부식문제점을 파악하여 해수용 4종 센서 IoT 모듈 패키징을 설계하고 외부 전원공급 방해 영향을 최소화한 태양광 발전을 적용한 항만 구조물 거동 계측 시스템을 제안하였다.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.171-180
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• 2014

This study is about effects of government R&D subsidies program participation factor for SMEs R&D performances. Currently, Government R&D subsidies program has been operating in various forms, and each company subsidies, facilities, equipment, personnel and training have been supported. Each of the companies is also involved with various factor of support to participate in the subsides program. Therefore, This study verifies the hypotheses that after government R&D subsidies program of project implementation, various participation factor of companies have an effect positive impact on business management skills of administrative performance. Also, This study verifies the hypothesis of an influence on the R&D investment and the technological capability of technical performance. Through such a analysis results will help to carry out guide for strategic R&D performance management of government R&D subsidies program participation companies.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.2
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• pp.17-25
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• 2015

This research is to analyze the mediating effect of corporate reputation between the organizational slack and corporate performance in venture SMEs. That is, after controlling the firm size, firm age, social capital, environmental uncertainty, we test three hypothesis. First, we test the hypothesis that organizational slack has a positive effect on corporate reputation. Second, we test the hypothesis that corporate reputation has a positive effect on corporate performance. Third, we test the positive mediating role of corporate reputation between organizational slack and corporate performance. For this research, we administered the questionnaire surveys, and got the 250 effective data(companies) of korean venture SMEs. We use SPSS 18.0, and analysis the validity, reliability, correlation and multiple regression analysis of research model. As a result, we can find the three meaningful results. First, organizational slack, especially not absorbed slack but unabsorbed slack, has positive effect on the corporate reputation. Second, corporate reputation has positive effect on corporate performance. Third, corporate reputation has mediating effect between organizational slack, especially not absorbed slack but unabsorbed slack, and corporate performance. Although this research has some limitations of generalization because of the limited size of samples, we has meaning information related to the venture companies in the academic and business field.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.6
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• pp.26-34
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• 2000

The considerations for remaining life of ACSR (Aluminum Stranded Conductors Steel Reinforced) in transmission lines have become gradually important to hold reliability and stability of power supply. The remaining life of ACSR exposed to the atmosphere for a long period may rely on deterioration caused by environmental indices such as atmospheric corrosion, galvanic corrosion, crevice corrosion and fatigue corrosion. One of reduction of useful life in overhead transmission lines built on the ridge of mountain is often caused by forest fires.This paper deals with investigation of strength deterioration performance of ASCR due to fires through several testing and analyzing data for tension load and extension of blazed ACSR. Test samples are ACSR 480[$\textrm{mm}^2$] conductors, which are artificially fired to regular durations. Mechanical properties such as tension load and extension for fired ACSR conductors are tested and estimation functions for mechanical performances corresponding to fire duration are determined. As a result, it can be verified that both tension load and extension of ACSR are reduced by increasing fire duration. Hence, it is obvious that ACSR due to forest fires may lead to mechanical deterioration.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.438-450
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• 2014

The statistical analyzing of environmental-friendly planning elements is getting important because it is getting concerned with the change of residential types and environmental friendly housing. However, in terms of the high-rise residential complex, paper about green building rating system and research about residential satisfaction to residents are lack. Therefore, this paper is analyzing of impotentness and satisfaction about housing subdivision, inside of building, facility, and maintenance. In addition, residential satisfaction(satisfaction, loyalty, preference) and impact relationship of environmental-friendly planning elements are analyzed by PLS structural equation. To sum up, first, improving of green building rating system in housing subdivision is impacted on loyalty if satisfaction was fulfilled. Second, increasing of environmental-friendly planning elements in inside of building is impacted on loyalty if both satisfaction and preference were fulfilled. Third, providing of green building rating system in facility and maintenance is analyzed as preference, but satisfaction hypotheses is not valued.

• Journal of the Korea Institute of Building Construction
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• v.11 no.2
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• pp.189-199
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• 2011

Installation of a proper root barrier in a green roof system is very important in order to protect the concrete slab of roof and the root penetration in the waterproofing layer. To select the proper root barrier materials and methods, it is necessary to understand the environmental conditions affecting the waterproofing-root barrier system in green roof construction site. Therefore, we suggested as the environmental performance indexes four kinds of performance requirements; root penetration, chemical attack by chemical agent or fertilizer, load impact by soil depth and size of plant, and water pressure. The related four test methods were suggested for the inspection of these performance indexes. In this research, we could suggest for kinds of test methods as standard test methods to evaluate the environmental performance of waterproofing-root barrier for greening roof system.

• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.557-567
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• 2007

In underground parking lots of apartment housing, the story height is increased by $300{\sim}400mm$ because of various ducts for HVAC. In order to reduce this story height, this study proposed the 'hybrid beam', which is composed of PC beam with embedded steel beam and insitu concrete. The depth of the hybrid beam is reduced by 300 mm and then the steel beam is embedded over the length of reduced depth to compensate for the loss of strength. Then, we performed the large-scale structural tests on 9 specimens and investigated the flexural behavior of the specimens. The parameters of tests were the shape of steel beam section, the length of the reduced depth, the stage of construction, the effects of slab and shear connectors. The test results showed that the specimens, after the insitu concrete has cured, has the flexural capacity which exceeds the required design capacity regardless of other parameters. On the other hand, the specimens of construction stage do not have sufficient strength. Based on these results, it is thought that the proposed hybrid beam with reduced depth is applicable to the underground parking lots of apartment housing as long as the support is placed at construction stage.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.5
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• pp.73-81
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• 2015

This research is designed to analyze the moderating effect of social capital between organizational slack and managerial practices for open innovation. After controlling the firm size, firm age, and environmental uncertainty, we test two hypotheses. First, we test the hypothesis that organizational slack has a positive effect on managerial practices for open innovation. Especially we focus on the managerial innovation and open innovation because recently managerial innovation and open innovation are more and more important. Second, we test the moderating role of social capital between organizational slack and managerial practices for open innovation. Because social capital is a kind of networking activity, we assume that social capital can contribute to managerial practices for open innovation through the networking activity. For this research, we administered the questionnaire surveys, and got the 250 effective data (companies) in Korea. Then we used the validity, reliability, correlation and multiple regression analysis by means of SPSS 18.0. As a result, we can find the two meaningful results. First, organizational slack, especially not absorbed slack but unabsorbed slack, has positive effect on managerial practices for open innovation. It is because absorbed slack such as excessive facilities, machines, or employees is not useful in managerial practices for open innovation. On the other hand, unabsorbed slack is useful in managerial practices for open innovation because unabsorbed slack such as excessive money or securities is very flexible and active. Taken together, the relationship between managerial practices for open innovation and unabsorbed slack is proven in terms of flexibility. Second, social capital has a moderating effect positively between organizational slack, especially not absorbed slack but unabsorbed slack, and managerial practices for open innovation. A prior study related to the relationship between managerial practices for open innovation and social capital doesn't exist yet, so this analysis result is very meaningful in academic respect. But this research has some limitations. First, this research is analyzed by limited region (Korea) and samples (250 companies), so more global regions and samples are recommended in the future. Second, we focus on managerial practices for open innovation in this paper, so the studies about technological practices for open innovation are recommended in the future.