• Journal of KSNVE
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• v.7 no.4
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• pp.571-578
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• 1997

Recently, many general-purpose packages for fluid-structure interaction problems have been announced. However, they have a lot of limitations to model structures in the fluid-structure interaction problems reasonably. Utilizing general-purpose packages such as MSC/NASTRAN and SYSNOISE, in this paper, a method to slove the radiation scattering problems with some accuracy in the fluid-structure interaction problems was developed. Using a simple model, the results from the presented method here are compared with those from SYSNOISE. The result shows quite a good agreement between the two methods. The problems, which could not be solved by SYSNOISE, were tried to solve with the presented method and results were presented. It was proved that this method could be safely used to solve fluid-structure interaction problems.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.252-257
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• 2006

Low vibration characteristics of a vehicle are mainly influenced by the local stiffness of the joint structure beam section. The method of substituting equivalent beam element to spring element for the joint is presented. Formation process of the equivalent beam joint modeling is described in terms of key section properties. To get required dynamic characteristics section properties of the equivalent beam element are set to design variables. The study shows that the equivalent beam joint model can be effectively used for low frequency vibration analysis of a vehicle.

• 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 Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.528-533
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• 1995

An analyical method is proposed to construct a clamp jointed structure as an equivalent stiffness matrix element in the finite element modal analysis of a complex beam structure. Static structural analysis was first made for the detail finite element model of the clamp joint. Utilizing the results of this analysis, the equivalent stiffness matrix element was buildup by using the flexibility influence coefficient method and Guyan condensation. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam. And the finite element analysis results were compared to those experimental modal analysis. Comparison shows doog agreement each other Furthermore the effects of normal contact(or clamping) load on the equivalent stiffness matrix was also examined. The equivalent stiffness matrix showed little change in spite of the remakable increase in the contact load on the clamp joint.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.177-184
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• 2008

Vehicle body frame stiffness affects the dynamic and static characteristics. Vehicle frame structure performance is greatly affected by crossmember and joint design. While the structural characteristic of these joint vary widely, there is no known tool currently in use that quickly predicts joint stiffness early in design cycle. This paper present the joint design factors affecting on low frequency vibration. The joint factors are joint panel thickness, flange width and weld point space. To study the effect on vehicle low frequency vibration, case studies for these factors are performed. The result can present design guide for high-stiffness vehicle.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.419-420
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• 2009

• Information and Communications Magazine
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• v.26 no.3
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• pp.52-59
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• 2009

본 고에서는 정보통신 기술과 전쟁이론의 결합을 통하여 새롭게 제시되고 있는 네트워크중심전(Network-centric warfare)의 기본철학을 지원하는데 있어서 필수적으로 요구되는 도구의 통합과 정보의 통합을 효과적으로 추진하기 위하여 통신 네트워크의 요구사항을 도출하고, 이를 만족시키기 위하여 BcN(광대역통합망) 아키텍처를 기반으로 Military-BcN 아키텍처의 기본 설계 방향에 제시한다.

• Proceedings of the Acoustical Society of Korea Conference
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• 1992.06a
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• pp.164-167
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• 1992

본 고에서는 후천적인 청각 장애나 노령화 및 산업화에 따라 난청자가 증가하고 있는 현대사회에서 난청자를 위한 통화대책을 강구하고자, 청각과 전화 통화와의 관계, 청력손실의 측정방법, 전화통화의 입장에서 본 난청의 분류, 청각 장애에 따른 청각 특성에 대해서 총괄하였다. 그리고 난청자가 전화통화를 하고자 할 때 청력손실의 정도와 장애 부위에 따른 통화방법을 고찰하였다. 여기에서는 가벼운 정도의 난청자인 경우에는 최저 가청한계를 고려한 고음향 출력 전화기, 또 난청의 정도가 심한 난청자는 골도 청각을 이용한 골도 전화기가 유용한 통화수단임을 소개하였다. 또한 CCITT 및 외국에서 적극적으로 검토하고 있는 문제로서, 보청기 착용자가 사회와 접촉하기 위한 수단인 보청기와 전화기의 결합 방법을 종합 검토하였다.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.217-218
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• 2009

• The Journal of the Acoustical Society of Korea
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• v.12 no.4
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• pp.63-71
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• 1993

본 고에서는 청각장애인 및 고령인을 위한 통화대책을 강구하고자, 청각과 전화통화와의 관계, 청각장애 정도와 장애부위에 따른 고출력 전화기, 골도 전화기의 복지형전화기 및 보청기와 전화기와의 결합방법을 종합 검토한다. 또한, 고령인을 위한 전화기로서 자동다디얼이나 수화증폭 등의 기능과 긴급시에 필요한 연락을 가능하게 하는 기능을 가지고 있는 긴급통보 기능의전화기에 관하여 기술한다.