• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.5
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• pp.56-64
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• 2020

A wind tunnel test of 29.7% scaled model of NASA Common Research Model was performed in small low speed wind tunnel. The wind tunnel model was fabricated in Aluminium in consultation with NASA Langley Research Center and AIAA Drag Prediction Workshop committee members. The static aerodynamic forces and moments were measured at a relatively low Reynolds number of 0.3 × 10⁶ due to tunnel capability limitations. Pitching moment of three types of model support(Fin sting, Blade sting and Belly sting) were compared. The pitching moment for corrected Belly sting and Fin sting were similar. The result of pitching moment for Blade sting was very small.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.10
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• pp.753-763
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• 2020

A wind tunnel test of 29.7% scaled model of NASA Common Research Model with belly model support was performed in small low speed wind tunnel. The static aerodynamic forces and moments of CRM were measured with belly sting support configuration. Pitching moments of belly sting with various fairings were compared and small interference fairing shape was found. The belly sting model support interference and reducing effect of fairing shapes with CFD analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.167-174
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• 2021

Computational Fluid Dynamics (CFD) was performed under low-speed wind tunnel test conditions using a 29.7% scale model of the NASA common research model. A wind tunnel test was conducted to measure the aerodynamic coefficient of the CRM with Belly sting model support configuration at a low Reynolds number of 0.3×106 and it was compared with the aerodynamic coefficient of CFD analysis. In order to verify the validation of the analysis, a computational analysis under the conditions of the advance research was performed and compared. The interference effect of the Belly sting model support affected not only the fuselage but also the main and tail wings.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.2
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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.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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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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• v.19 no.2
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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.

• Journal of the military operations research society of Korea
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• v.28 no.1
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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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• v.5 no.1
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1528-1538
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• 2016

Common data link systems are designed to transmit the imaginary and signal intelligence data at long distance air-ground line of sight(LOS) link. In this paper, we analyze the received power variation according to the communication distance of the common data link using curved earth 2-Ray model suitable for received signal power analysis of long distance air-ground wireless channel. We propose optimal elevation angle control method of the receiving antenna to reduce a power variation caused by ground-reflected wave. Proposed method can get additional link margin compared to the conventional method without any additional hardware performance enhancement.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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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.