• Composites Research
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• v.27 no.4
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• pp.123-129
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• 2014

Ceramic matrix composites (CMCs) consist of such reinforcements as carbides, nitrides, borides and oxides, which have high melting points, low density, high modulus and high strength, for the purpose of increasing toughness. These materials are used for heat shielding systems for aerospace vehicles, high-temperature gas turbine combustion chambers, turbine blades, stator vane parts, etc. Oxide CMCs are used for the components of burner and flame holder and the high-temperature gas duct. CMCs are also applied to brake disks, which are subjected to severe thermal shock, and slide bearing parts under heavy loads. The research and development of the CMC are progressed for the strategic purpose in defense and energy industry; for instance, for aerospace applications in the U.S., and for hyper-speed aircraft, gas turbines, and atomic fissions in U.S., Japan, and Europe.

• Proceedings of the Korean System Dynamics Society
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• 2003.02a
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• pp.29-55
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• 2003

최근의 통신서비스 시장은 경쟁의 도입과 기술의 발전이라는 두 축에 힘입어 양질의 서비스를 보다 저렴한 요금으로 소비자들에게 제공하고자 노력하여 왔다. 그러나 이러한 통신서비스의 질적 향상 노력에도 불구하고 여전히 통신서비스의 품질은 소비자들의 기대수준에는 미치지 못하고 있다는 지적이 있다 더욱이 문제가 되는 것은 소비자가 인지하고 있는 통신 서비스 품질의 기대수준은 시간의 흐름에 따라 동태적으로 변화하는 것이어서 한 시점에서의 통신 서비스 품질 수준의 측정으로는 정책적으로 큰 의미를 설명하기 어려운 실정이다. 이와 관련하여 많은 선행 연구들이 다양한 측면에서 시행되어져 왔지만 이제까지의 많은 선행 연구들은 대부분이 통신서비스의 특성을 제대로 고려하지 않고, 고객만족의 향상과 불일치를 가져오고 있는 성능품질만을 측정한다거나, 시간의 흐름에 따라 변화해 가는 소비자가 서비스에 대해 인지하고 있는 중요도나 기대수준을 고려하지 않고 있으며, 각 구성요소간의 동태적 인과고리에 대한 고려 없이 연구가 이루어져 전반적인 통신 서비스의 고객만족을 전체적인 시각에서 평가한 연구는 극히 드물다. 따라서 본 연구는 통신서비스의 고객만족을 피드백 관점, 동태적 관점, 사실적 관점의 시스템 다이내믹스 방법론을 적용하여 전반적인 동태적 고객만족 모형을 구현하고 이를 정책적으로 활용할 수 있는가에 대한 접근을 시도하였다. 고객만족은 결코 한순간에 머물러 있는 것이 아니며 체감품질 및 기대수준의 영향을 받아 지속적으로 변화해간다 따라서 어떻게 기대수준을 관리하고 고객의 기대에 부응하는 체감품질을 관리하는 것이 지속적인 고객만족을 획득할 수 있는 가를 시뮬레이션 모형을 통해 가시적으로 시스템의 행태를 구현함으로써 그 이해의 폭을 넓히고자 시도하였다.으로써 웹에서의 혁신적이며 크로스 사이트, 크로스 장르적인 컨텐츠 플래닝의 가능성을 시사하는데 의의가 있다고 하겠다.y used to some of interactive storytelling through hyper text in CD-ROM and web sites. More complicated and different structured models were born through games that offered graphics, virtual spaces and interactivity. When drawn onto a structural graph, few attributes and similarities seem to occur. This paper will try to outline and discuss structural graphs of interactive storytelling methods and suggest some ways for better storytelling design.eal sales volume, but the case study could verified that this method is effective to the evaluation of marketability in case of completely new product got on the typical category and the product category could be set up the population clearly.의 무게와 부피는 24주간 다소 감소하는 경향을 보였으나 통계적인 유의차는 없었다. 냉동저장 감자의 무게와 부피 변화는 48주간 전혀 없었다. 상온 냉장저장 감자의 조직의 강도(hardness)는 24주

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.266-269
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• 2003

This study predicts the maintenance and operation level of the bridge based on the LCC concept. In order to predict the LCC of the given case, suggested the maintenance and operation level after reviewing other related materials. Apply the real information of the maintenance and operation to the three casesof the maintenance and operation level (real, current, and prevented maintenance and operation level). And based on such analytical measures, maintenance and operation costs and LCC in maintenance and operation level, have been predicted: therefore, suggests the basic information about maintenance and operation level for the bridge. With a result of this study, we could obtain (1)the LCC of PSC-bridge and RC-bridge is more economy than Steel-bridge and (2)more active maintenance and operation of a bridge is absolutely necessary.

• Korean Management Science Review
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• v.32 no.1
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• pp.83-100
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• 2015

We analyze a duopoly competition when two firms face input cost increases. The objective of this study is to determine the firms' optimal strategy between a price increase and downsizing under conditions of a spatially differentiated market and consumers' diminishing utility on the product size. We develop a theoretical model of two competing firms offering homogenous products using the standard Hotelling model to determine how firms' optimal strategies change when facing input cost increases. In this paper, there are two types of duopoly competitions: symmetric and asymmetric. In the symmetric case, the two firms have the same marginal cost and are producing and selling identical products. In the asymmetric case, the two firms have different marginal costs. The results show that the optimal strategy decision depends on the size of the input cost increase and the cost differences between the two firms. We find that when two firms are asymmetric (i.e., they have different marginal costs), the two firms might choose asymmetric pairs of strategies in equilibrium under certain conditions. When the cost differences between the two firms are sufficiently large and the cost increase is sufficiently small, the cost leader chooses price increase, and the cost-disadvantaged firm chooses downsizing in equilibrium. This asymmetric strategy reduces price competition between two firms, and consumers are better off. When the cost differences between the two firms are sufficiently large, downsizing is the dominant strategy for the cost-disadvantaged firm. The cost-disadvantaged firm finds it more profitable to reduce the product size than to increase its price to reduce price competition, because consumers prefer downsizing to price increases. This paper might be a good starting point for further analytical research in this area.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.4
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• pp.3-12
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• 2003

Due to the high demand on energy resources accompanied by continuing industrialization and urbanization, the world marine transportation of crude and product oils is being gradually increased. In Korea, we are exposed to the large-scale marine oil spill accidents because a very large oil tanker of 300,000 tonnage must enter Korean Ports every day to meet the domestic demand on oils. Although we are exerting our strength to reduce the probability of marine oil pollution accidents, a unrestorable oil spill is to occur owing to human errors, severe weather conditions, or combined causes. Thus, area contingency plan equipped with appropriate management system for response and restoration for the worst case discharge scenario must be entirely prepared to protect mine environments and coastal resources. In particular, we are focusing on the Environmental Sensitivity Index Map(ESI Map) to reduce the environmental consequences of both spills and clean-up efforts by specifying protection Priorities in advance and identifying in-situ response strategies. In this paper, Korean ESI Map is introduced with brief definition of sensitivity to oiling and main features of the software developed hitherto.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.389-394
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• 2017

In a conventional ship structure, stiffeners with an asymmetric section, such as inverted angles, are used widely despite the disadvantage of strength compared to the stiffeners with a symmetric section, such as a built-up T. On the other hand, T-type built-up members are attracting more attention than L-type inverted angles due to the increased size of ships. The purpose of this study was to develop an optimal design program for a built-up T, and apply an evolution strategy as an optimization technique. In the optimization process, the gross thickness concept was adopted for the design variables and objective function, and the constraints are set up based on HCSR (Harmonized Common Structural Rules). Using the developed program in this study, the optimal stiffener design was carried out for 300K VLCC and 158K COT of which the orders were obtained lately. The optimal results revealed the weight reduction effect of 144 tons and 60 tons, respectively.

• The Journal of the Korea Contents Association
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• v.16 no.9
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• pp.628-637
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• 2016

The purpose of this study was to explore factors influencing quality of life among cancer survivors in order to identify strategies for cancer survivors to go back to normal life and carry on stable and high quality life. This study used Korea National Health and Nutrition Examination Survey(2010-2014), conducted by Korea Centers for Disease Control and Prevention(KCDC). The sample of this study was 610 cancer survivors and their average time since diagnosis was about 11 years. The most powerful influencing factors for quality of life among cancer survivors were activity limitation(${\beta}$=.30, p<.001), followed by age(${\beta}$=-.20, p<.001), subjective health status(${\beta}$ =-.19, p<.001), and economic status(${\beta}$=.12, p=.004). According to the result, limitation on daily activities or social activities due to physical or mental debilitation was a strong factor that lowers quality of life among cancer survivors. Hence, there is a need for manpower and infrastructure that facilitates, supports, and manage daily activities of cancer survivors.

• Air Cleaning Technology
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• v.28 no.1
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• pp.29-40
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• 2015

중국의 급속한 산업화로 대기, 수질, 폐기물 등 환경오염문제가 심화, 고착화되면서 이를 개선하기 위해 중국 정부는 환경규제를 지속적으로 강화하고 있다. 또한 외국인 투자유치로 제조업 육성에 어느 정도 성공을 거둠에 따라 외국인 투자 유치와 제조업 경영활동에 있어 환경 이슈를 매우 중요시하고 있어 신규 및 사업확장에 제동이 걸리고 있다. 중국은 신규법인수 기준으로 우리나라의 최대 해외직접투자국이며, 제조업종에 대한 투자금액이 전체 투자금액의 88.3%를 차지하고 있다. 중국에 진출한 기업들은 중소기업이 전체 진출기업의 약 90%로 중국의 환경규제 강화는 중국에 진출한 우리 중소기업들에게 직접적인 영향을 미치고 있다. 중국 정부는 분야별 환경목표를 강화하고 오염물질배출 업체를 퇴출시키는 등 강력한 조치를 전개하고 있으며, 중앙 정부의 환경목표 강화 기조와 더불어 해당 지역민의 친환경에 대한 요구가 점차 커짐에 따라, 각 지방정부는 환경 관련 지역 목표 달성을 위해 업체 관리감독을 대폭 강화하고 있는 추세이다. 이러한 중국의 환경규제 강화는 진출 기업이나 진출을 준비하는 기업들의 설비투자비나 오염배출비용 부담 증가 등 상당한 리스크로 작용하고 있으며 향후에도 중국의 환경규제 강화 기조는 지속될 것으로 전망된다. 실제 중국에 진출한 기업들은 환경규제를 직접적으로 체감하고 있다. 규제집행의 강도가 눈에 띄게 높아져 엄격한 기준을 적용받고 처벌수위 역시 높아졌으며, 과거 관시를 통해 원만한 해결이 가능했다면 이제는 환경규제에 대해 원칙적이고 보수적인 공무원의 태도로 인해 관시로도 해결이 어려운 경우가 다반사이다. 또한, 주민들도 환경규제에 대한 인식수준이 높아짐에 따라 미미한 사안에도 즉각적인 반응을 보여 민원제기 사례가 빈번히 발생하고 환경안전 기준이 점점 높아짐에 따라 이에 대응하기 위해 환경안전 설비추가, 친환경연료 사용 등 추가적인 비용이 발생하고 있다. 이에 이미 진출한 기업들은 소재지 환경규제의 강화 전망 및 이로 인한 손실정도를 사전에 파악하고 다양한 옵션에서 대응전략을 마련해야 하며, 향후 중국 진출계획을 가지고 있는 기업들은 진출에 앞서 지역별로 차별화된 시장기회와 환경규제 강도 등 현지 실사를 통한 현장중심 리스크 분석을 실시해야 한다. 또한 이미 진출한 기업 및 진출예정 기업 모두 환경규제가 강화되고 있는 중국에서 사업을 하기 위해서는 법규와 기본원칙을 반드시 준수하고 규제가 더 강화될 것 이라는 기조를 인식할 필요가 있다.

• Journal of The Korean Association of Information Education
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• v.16 no.2
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• pp.151-164
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• 2012

The purpose of this study was to examine moderating effect of academic self-efficacy and learning flow between social presence and academic achievement of cyber university students. For this purpose, the 371 students of W cyber university were participated in the web-survey system for two weeks at the end of second semester in 2011. The results of this study through hierarchical multiple regression analysis indicated that social presence significantly predicted on academic achievement. Academic self-efficacy was not significant moderating variable between social presence and academic achievement. And Learning flow was used as a significant moderated variable in the relationships among social presence and academic achievement. Based on these study results, effective management strategies for improving cyber university students' academic achievement were proposed.

• The Journal of Korean Association of Computer Education
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• v.15 no.3
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• pp.61-69
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• 2012

The purpose of the present study is to examine the prediction of academic self-efficacy, learning flow, academic stress, and emotional exhaustion on course satisfaction of cyber university students. The total of 536 students registered in a meditation course at W cyber university was participated in the web-based survey in the spring semester of 2011, and finally 331 students completed this survey. The hypothetical model proposed was composed of academic self-efficacy, learning flow, academic stress, emotional exhaustion as the predictor variables, and course satisfaction as the criterion variable. According to the results of this study through multiple regression analysis, academic self-efficacy, learning flow, academic stress, and emotional exhaustion significantly predicted on course satisfaction. Based on the results of this study, effective methods and strategies for constructing cyber educational environments that enable students to improve academic self-efficacy and learning flow as well as reducing academic stress and emotional exhaustion should be considered.