• 한국추진공학회지
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• 제24권5호
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• pp.56-64
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• 2020

29.7% 축소 NASA 표준 연구 모형에 대하여 소형 저속 풍동에서 시험을 수행하였다. 풍동시험 모형은 NASA Langley 연구소와 AIAA 항력추정 워크숍 위원회의 지침에 따라 알루미늄으로 제작하였다. 풍동의 능력 한계 등으로 상대적으로 낮은 레이놀즈수인 0.3 × 10⁶ 에서 정적 힘과 모멘트를 측정하였다. 세 가지 타입(핀 스팅, 블레이드 스팅, 벨리 스팅) 모형지지부에 대하여 피칭모멘트를 비교하였다. 보정된 벨리 스팅과 핀 스팅에 의한 피칭모멘트 보정량은 비슷하였으며 블레이드 스팅에 의한 피칭모멘트 값이 가장 적었다.

• 한국항공우주학회지
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• 제48권10호
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• pp.753-763
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• 2020

29.7% 축소 NASA Common Research Model을 벨리 스팅 모형지지부에 장착하여 저속에서 풍동시험을 수행하였다. 다양한 형상의 페어링을 장착한 벨리 스팅 모형지지부에 대하여 공력계수를 측정하는 시험을 수행하였으며 그 결과를 고찰하였다. 벨리 스팅 모형지지부에 장착된 CRM 형상을 이용하여 힘과 모멘트를 측정하였다. 벨리 스팅 페어링 형상 변화에 따른 피칭모멘트로부터 벨리 스팅 간섭 효과를 감소시키는 형상을 찾았다. 전산해석을 통해 벨리 스팅 모형지지부의 간섭과 시험부 페어링의 간섭 감소효과를 확인하였다.

• 한국항공우주학회지
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• 제49권3호
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• pp.167-174
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• 2021

NASA Common Research Model의 29.7% 축소 모형에 대하여 저속 풍동시험 조건으로 수치해석을 수행하였다. 낮은 레이놀즈수 영역인 0.3×106에서 Belly sting 모형 지지부를 장착한 CRM의 공력계수를 측정하는 시험이 수행되었으며, 수치해석 결과와 비교하였다. 해석의 타당성을 검증하기 위해 선행연구 조건으로 전산해석을 수행하여 비교하였다. Belly sting 모형 지지부 유무에 대한 해석 결과 지지부에 의한 간섭 효과로 동체뿐만 아니라 주날개, 꼬리날개까지 공력에 영향이 있음을 확인하였다.

• 대한산업공학회지
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• 제43권2호
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• pp.120-126
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• 2017

This paper has proposed the development direction and R&D analysis approach that the diversity of defense R&D process and product should be mainly under consideration. It has shown that there is a fair possibility of the various quality assess to meet the R&D requirements in defense-based. Thus, the analysis on multiple quality elements is carried out with defense R&D characteristics. Especially, a quality management master planning based on the quality model of establishing defense R&D policy has proposed, identifying relevant quality characteristics on the R&D of weapon system and the R&D of core technology. That is, this paper is not only interested in determining an appropriate model for improving the quality of a R&D weapon system but also argued efforts in order to reap the best possible outcome and process on both the R&D of weapon system and quality of the R&D of core technology including present R&D activities.

• 품질경영학회지
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• 제46권3호
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• pp.397-410
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• 2018

Purpose: A main aims to classify quality attributes for quality assurance activities of military supplies by company size, and to derive the necessity for business improvement by company size to improve customer satisfaction through customer satisfaction coeffiecient and PCSI Index. Methods: Through a survey of defense and general businesses located in Busan and South Gyeongsang Province, the quality of service elements are classified and the client satisfaction factor and PCSI is calculated for the quality assurance activities. Results: Determine the current level of customer satisfaction with the quality of the Defence quality assurance service and present operational factors that need improvement by size of the company. Conclusion: The attractive quality of service factors for quality assurance work were in common and different and the need for improvement was identified based on differences in PCSI Index by Company size.

• Management Science and Financial Engineering
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• 제19권2호
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• pp.1-11
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• 2013

An interesting puzzle in business practices is that although many researchers emphasize the benefits of a revenue-sharing contract, a wholesale contract has remained to be the most common contractual form. By introducing the concept of unobservable efforts, we examine the contractual efficiency of a wholesale contract and a revenue-sharing contract. The multi-task agency model and experimental design approach are used to analyze the relationship between the contractual efficiency and parameters. A major finding of our study is that a wholesale contract coordinates unobservable efforts, while it fails to coordinate the order quantity decision. Because unobservable efforts have mixed effects on the contractual efficiency, the superiority of contract type depends on parameters. This finding implies that a wholesale contract can be a competitive contract, especially when unobservable efforts are heavily involved. Our conclusion is that the current popularity of a wholesale contract is manager's rational response to complex supply chain environments rather than irrational behaviors.

• 한국국방경영분석학회지
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• 제28권1호
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• pp.115-135
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• 2002

The limits of current DN(Defense networks), private and closed network, become to reality; for Example, high expense of construction and maintenance of networks, restriction of new subscribers on DN. Therefore, a network using web environment that reflect fast development of If and IS(Information Security) technology is demanded for MND. Meeting the requirement of reliable IS system and extension and improvement of DN using common network, we can reduce the expense to extend, maintain, repair DN, form the environment that makes military business cooperate better with civil company and government agency, advance implementing Defense computing and networking service for field small size units that was a exception of Defense digitalization. But it is essential to construct DN based on common network that there are security requisites; confidentiality, integrity, availability, efficiency, log, backup, restoration, that have to be realized at demanding level for IS. This thesis suggested four measurements; replacement DN with common network to resolve the requirements of building new network and improvement of performance for private DN, linkage with common network for new requirement, distribution of traffic using common network, configuration of DN using Internet and Proposed a refinement of IS management organization to treat security threat of common network flexibly, and LAN IS standard model of DN based on the web environment.

• Asian Journal of Innovation and Policy
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• 제5권1호
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• pp.1-18
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• 2016

Catch-up is a well-known and familiar terminology for innovation scholars in developing countries such as Taiwan, Korea and China. The strategy, however, is too difficult to perform in each industry. This study looks into a catch-up strategy that Apple and Xiaomi used and examines the results on the creative imitation of business model in the smartphone industry. It is quite surprising that even Apple is based on catch-up strategy. They wanted to catch-up Nokia. Our case study shows that these two companies quickly caught up with the leaders, and the common feature of their strategy is characterized as creative imitation of business model. Creative imitation of business model is different from creative imitation of innovation. Furthermore, this research confirms that the creative imitation of business model leads to aggressive creative innovation.

• 한국통신학회논문지
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• 제41권11호
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• pp.1528-1538
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• 2016

영상정보용 데이터링크는 장거리의 공중-지상 환경에서 영상과 신호정보를 전송하도록 설계된 통신 시스템이다. 본 논문은 장거리 공중-지상 채널환경의 신호 분석에 적합한 곡면지구 2-Ray 모델을 사용하여 영상정보용 데이터 링크의 통신거리에 따른 수신전력 변화 폭을 분석하고 지면 반사파에 의한 수신전력의 변화폭을 경감할 수 있는 수신 안테나의 최적 고각 제어방법을 제안한다. 제안된 방법은 추가적인 하드웨어 성능 향상 없이도 기존의 고각 제어 방법에 비하여 추가적인 링크마진을 확보할 수 있다.

• 한국군사과학기술학회지
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• 제21권3호
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• pp.386-395
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• 2018

Quality management is essential to achieve the desired quality throughout a program. Especially in phase of research and development(R&D) of a program, that is an effective and efficient way to achieve the quality goals and improve the quality of a program in total life cycles. For applying the quality management to a R&D program, characteristics of the program should be considered in various aspects. In this study, the characteristics of developments of defense weapon systems were analyzed and the meaning of quality in that field was defined. And then, application methods of the quality management were established and the quality management model with four view points(external, organization, programs, practices) was proposed. In addition, detailed tasks of the quality management activities were described and some examples of applying the model were introduced.