• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.230-237
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• 2003

Ultrasonic testing method has been developed to evaluate adhesive layers in blast tube for the reliability of the rocket. The main objective of the present work was to find debonding and missing adhesive in epoxy layer between steel and FRP layers. In this approach, the ultrasonic reflection from the interface between the steel sheet and the epoxy adhesive is measured with a high-frequency pulse-echo setup in order to identify contact debonding and missing adhesive. Then, the steel sheet is excited to resonance by low-frequency ultrasound, and the gap size underneath the measuring location is estimated from the resonance responses. For practical application in industry an automated testing system has been developed where the proposed approach is implemented. The performance of the proposed approach has been verified by actual measurement of gap sizes from the cross-sections of cut specimens using an optical microscope.

• Journal of Korean Society for Quality Management
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• v.46 no.1
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• pp.169-188
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• 2018

Purpose: The purpose of this study is to analyze low-temperature starting performance of the light attacker and to search and improve the aircraft system including battery and Battery Charge and Control Unit(BCCU). Methods: In order to improve the starting up performance of the light attacker at low-temp, various deficiency cause were derived and analyzed using Fault Tree Analysis method. As a result, it was confirmed there were drawbacks in the charging and discharging mechanism of the battery. The inactivation of the battery's electrolyte at low-temp and the premature termination of the battery charge were the main cause. After long error and trial, we improved these problems by improving performance of battery and optimizing the charging algorithm of BCCU. Results: It was confirmed that the problems of starting up failures were solved through the combined performance test of the battery and BCCU, the ground test using the aircraft system and the operation test conducted by Korea Airforce operating unit for 3 months in winter. Conclusion: This study showed that the improvement of quality reliability was achieved and thus the start-up performance issue of the light attacker has been resolved at low temperature. And it is expected that the design methodologies of temperature-affected electrical system of aircraft will contribute to the development of the aircraft industry in the future.

• Journal of Mechanical Science and Technology
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• v.18 no.6
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• pp.904-914
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• 2004

The fiber reinforced composite material is widely used in the multi-industrial field because of their high specific modulus and specific strength. It has two main merits which are to cut down energy by reducing weight and to prevent explosive damage proceeding to the sudden bursting which is generated by the pressure leakage condition. Therefore, Pressure vessels using this composite material can be applied in the field such as defence industry and aerospace industry. In this paper, for nonlinear finite element analysis of E-glass/epoxy filament winding of composite vessel subjected to internal pressure, the standard interpretation model is developed by using the ANSYS with AutoLISP and ANSYS APDL languages, general commercial software, which is verified as useful characteristic of the solution. Among the modules of the system, both the process planning module for carrying out the process planning of filament wound composite pressure vessel and the autofrettage process module for obtaining higher residual stress will minimize trial and error and reduce the period for developing new products. The system can serve as a valuable system for experts and as a dependable training aid for beginners.

• Journal of Korean Society for Quality Management
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• v.49 no.1
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• pp.97-112
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• 2021

Purpose: The purpose of this paper is to analyze the technology convergence and its characteristics, focusing on the defense technologies in South Korea. Methods: Patents applied by the Agency for Defense Development (ADD) during 1979~2019 were utilized in this paper. Information Entropy analysis has been conducted on the patents to analyze the usability and potential for development. To analyze the trend of technology convergence in defense technologies, Social Network Analysis(SNA) and Association Rule Mining Analysis were applied to the co-occurrence networks of International Patent Classification (IPC) codes. Results: The results show that sensor, communication, and aviation technologies played a key role in recent development of defense science and technology. The co-occurrence network analysis also showed that the convergence has gradually enhanced over time, and the convergence between different technology sectors largely emerged, showing that the convergence has been diversified. Conclusion: By analyzing the patents of the defense technologies during the last 30 years, this study presents the comprehensive perspectives on trends and characteristics of technology convergence in defense industry. The results of this study are expected to be used as a guideline for decision making in the government's R&D policies in defence industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1831-1837
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• 2014

Unmanned combat vehicles is recognized as a key tool to utilize the military combat power in the area of science and technology. It can be expected to minimize the lose of human life and increase the military power. Unmanned combat systems are based on the complex operation concept and the unit system can be manufactured by combination on unmanned combat vehicles. For the unmanned combat systems, military power exists to sustain the acquisition establishment system and unmanned technology, which is considered to give the suitability such as application area.

• Journal of Digital Convergence
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• v.4 no.1
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• pp.17-30
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• 2006

Recently, Modeling and Simulation, which have been received attention in various in dustries such as national defence, eduction and entertainment, have been researched, and related applications have been developed actively. Especially, it is focused on the to chnology of a virtual reality and a virtual simulation which represents the implementation technology for the simulation education related to the e-Learning industry. However, a solution is needed to fulfill the lack of technology and research about standardize d data elements which could be applied to virtual simulation technologies in common. Therefore, this article suggests the virtual simulation data elements to increase the educational effect of a virtual simulation and interoperability of data among LMS through reference to korean and international standards and the result of related area analysis. In other words, this article aims to define the expression of data element and to propose the guideline elements in the virtual simulation scope.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.850-858
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• 2011

The risk analysis plays an important role in weapon system acquisition project due to uncertainties in the acquisition process. But in domestic, studies on risk analysis are insufficient and risk cost is not included in acquisition budget in policy. Therefore, in this study, we suggest a method that measures risk or success probability of project using the stochastic model. In particular, in order to calculate the success probability, we apply the joint probability distribution model of cost and schedule that are critical factors influencing the project risk. And also we verify the applicability of this model in Korean defence industry environment through case studies.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1428-1432
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• 2007

The object of this paper is development of pneumatic servo actuator technique for energy saving type. In this paper, consist of pneumatic servo actuator technique is pneumatic servo valve, pneumatic motor and cylinder. This technique applied a automobile, aerospace engineering, a ship, defence industry and industrial machine because it have high response, high speed, high precision control, low friction etc., compare with previously technique. But it depend on import the whole quantity. So this study, suggest that through the development of servo actuator applicable the use of industrial field.

• The Journal of Information Technology
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• v.3 no.1
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• pp.155-175
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• 2000

Electronic commerce has already existed for over 20 years. In sectors such as retail and automotive, electronic data interchange(EDI) for application-to-application interaction is being used regularly. For defence and heavy manufacturing, electronic commerce life-cycle management concepts have been developed that aim to integrate information across larger parts of the value chain, from design to maintenance, such as CALS(Computer Assisted Life-cycle Support or Computer Aided Logistics Support). Bolero's mission is to provide guaranteed and secure delivery, in electronic form, of trade documentation, globally, based on a binding legal environment and common procedures. Bolero will also provide a platform for provision of neutral cross-industry services.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.4
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• pp.12-22
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• 2001

Vehicle driving simulators hale been used in the development and modification of models. A simulator can reduce cost and time through a variety of driving simulations in the laboratory. Recently, driving simulators have begun to proliferate in the automotive industry and the associated research community. This paper presents the hardware and software developed fur a driving simulator of construction vehicles. This effect involves the real-time dynamic analysis of wheel-type excavator, the design and manufacturing of the Stewart platform, an integrated control system of the platform, and three-dimensional graphic modeling of the driving environments.