• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.349-353
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• 2013

공동주위의 유동에 대한 연구결과를 보면 개방형 공동(L/D<10)과 밀폐형 공동(L/D>13)으로 구별하는 데 개방형 공동은 앞전에서 발생한 자유전단층이 뒷전 부근에 재부착하여 공동을 완전히 연결하므로, 자유전단층과 외부유동과의 상호작용으로 발생하는 심한 압력변화에 의해 진동현상이 나타나게 된다. 이것은 큰 소음을 유발하고, 구조물의 고장 혹은 파괴의 원인이 되기도 하고, 공력 성능 및 안정성에 해를 주고 민감한 계기를 손상 시킬 수도 있다. 본 논문에서는 공동을 연구하기 위해 EDISON_CFD를 사용하여 공동의 시뮬레이션하기 위해 격자를 구성하고 세장비를 각각 1/5, 1/3, 1/2, 1, 2, 5 로 변화를 주어 M=1.5 일 때 밀도, 압력, 마하수와 유동구조를 세장비에 따라 결과를 비교, 분석한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.983-994
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• 2014

In this paper, we analyze the telecom services and their socio-economic effect of using open spectrum, which is to access sharing spectrum. For this, we suggest a concept and a classification of open spectrum as spectrum access model and make a survey for analyzing the socio-economic effect of spectrum, 2,605 MHz which is candidated for sharing between 2.9~5.925 Hz in Korea. From survey results, we propose Mobile Telecommunications Assist Service and WiFi as the most effective services and Smart Car Service and M2M, IoT, and RFID/USN Service as the effective services to open spectrum.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.193-201
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• 2011

This paper presents the holistic notion and model of an open social u-learning community, anchored with open content, providing an interactive online study group experience akin to sitting with study buddies on a world-wide campus quad. The interactive social u-learning community design helps conceptualize and maximize advantages of ubiquitous environment in learning. The model is enabled by state-of-the-art web technologies; real-time collaboration technologies for a highly interactive experience; intelligent recommender systems to help learners connect with relevant content and other learners; and mining and analytics to assess learner outcomes. Hence, u-learning design is highly scalable yet interactive and engaging.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1921-1926
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• 2004

The tone generation mechanism and aeroacoustic characteristics have been investigated for flow over open cavities using direct acoustic numerical simulations. Physically the tone generation mechanism of open cavity is more complicated when flow instabilities are excited by the correlation effects of flow parameters. From non-dimensional parameter studies in very low Mach number range, it is shown that characteristics of cavity resonance inherently involve typical acoustic pattern at each discrete tone frequency, and especially in laminar flow the fundamental tone frequency is determined within flow instability criterion of laminar shear layer as well as cavity geometry, length to depth ratio.

• Journal of Korea Technology Innovation Society
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• v.15 no.3
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• pp.722-743
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• 2012

Confronted with increasing global competition and rising research and development risks, the global open innovation has receiving increased attention. This study empirically investigates whether or not international cooperative R&D is effective by evaluating the quality indicators with the patents with international co-applications. The number of patents with international co-applications has dramatically increased in recent years. According to the results, the outcome from international cooperative R&D is prominent in term of all the evaluation criteria such as the number of citation, patent families, claims, and et cetera, compared with that from domestic cooperative R&D. Based on the patent quality, the information technology sector holds the top spot and high-tech sectors such as bio and automobile industries show the better quality performances. By identifying high betweeneess centrality in the network analysis of international cooperative R&D, the US is indicated as the most central country in such cooperative activity, and then Germany, the UK, Canada, and France come after.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.2
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• pp.159-179
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• 2024

Based on the case of collaboration between large companies and startups, this study suggests the importance of establishing mutual cooperation and trust relationships for the success of open innovation strategy from the perspective of cooperative game theory. It also provides implications for how this can be implemented. Due to information asymmetry and differences in organizational culture and decision-making structures between large companies and startups, collaboration is likely to proceed in the form of non-cooperative games among players in general open innovation, leading to the paradox of open innovation, which lowers the degree of innovation. Accordingly, this study conducted a case study on collaboration between large company 'G' and startup 'S' based on the research question "How did we successfully promote open innovation through cooperative game-type collaboration?" The study found that successful open innovation requires (1) setting clear collaboration goals to solve the organizational problem between large companies and startups, (2) supporting human resources for qualitative growth of startups to solve reliability problems, (3) leading to strategic investment and joint promotion of new projects to solve the profit distribution problem. This study is significant in that it contributes to expanding the discussion of the success factors of open innovation to the importance of interaction and strategic judgment considering the organizational culture and decision-making structure among players, and empirically confirming the success conditions of open innovation from the perspective of cooperative game theory.

• Electronics and Telecommunications Trends
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• v.28 no.5
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• pp.198-208
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• 2013

개방형 혁신에 대한 관심이 고조되고 인터넷을 통한 공동작업이 활발해짐에 따라, 가상의 작업공간을 지원하는 시스템의 필요성이 증대되고 있다. 특히, R&D 분야에서는 연구원이 보유한 전문기술들을 묶어서 집단지성으로 이끌어 내어 창의와 협업을 지원하는 R&D 협업시스템의 개발이 요구된다. 따라서 본 논문에서는 이식성이 높고 다양한 R&D 협업 환경에 능동적으로 대처할 수 있는 확장성과 안정성을 구현한 R&D 협업시스템을 소개한다. 향후에도 R&D 및 ICT 환경변화에 따른 지속적인 보완 개발을 통하여 R&D분야에 적용할 경우 미래 전 산업 연구 개발 분야에 큰 도움을 줄 수 있을 것으로 기대된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.10
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• pp.995-1004
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• 2014

Due to the development of spectrum use technology and various services based on radio spectrum, the scarcity of spectrum has been heightened. In this circumstances both the efficiency and fairness of spectrum use need to be raised. Open spectrum access can be a useful approach for both goal. For the open spectrum access the legal institution needs to be reformed to enable it. From the starting point of spectrum use till the end of spectrum use there can be various issues of rights and obligations. So the legal institution for various legal status of spectrum use and establishment and continuous management of DB and fast and respectable dispute resolution mechanism is required.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.281-284
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• 2008

The flow of combustor in scramjet engine is supersonic speed. So residence time and mixing ratio are very important factors for efficient combustion. This study used open cavity on fuel/air mixing model and laser schlieren was carried out to investigate flow characteristics around a jet orifice and a cavity. A source of illumination has 10 ns endurance time so it can observe unsteady flow characteristics efficiently. Pressure was measured by varying momentum flux ratio. And the change of critical ignition point was observed to change of momentum flux ratio.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.4
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• pp.9-15
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• 2009

The flow of combustor in scramjet engine has supersonic speed so that the residence time and mixing ratio are very important factors for the efficient combustion. This study used open cavity(L/D=4.8) as a fuel/air mixing model. Laser schlieren visualization and pressure measurement were carried out to observe the flow characteristics around a jet orifice and a cavity at the time of fuel injection. As a result of 10ns laser schlieren, unsteady flow which was around the cavity could be observed effectively. Pressure was measured that momentum flux ratio(J) was changed. And the change of critical ignition point could be observed by the momentum flux ratio changed.