• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.1-9
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• 2013

ADD (Agency for Defense Development) has developed the naval warfare simulation environment (QUEST), this paper describes the model library of naval weapon systems for the application of underwater warfare simulation included in the QUEST. Models are basically developed in order to measure the effectiveness and tactical development of underwater engagement between ships and weapons. Analyzing the mission space of underwater engagement and the functionality of the legacy models, we define standards of the model structure and developed the model components. Each components are the well-defined environment, system, subsystem, algorithm models, and the interfaces are defined between them. Users can construct a model in an efficient way to various warfare scenarios using the re-usable model components and co-work with the common model library.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.63-65
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• 2012

최근 군사 모의 소프트웨어는 사용자의 다양한 요구 변화에 빠르게 적응하기 위해 컴포넌트를 조합하여 구성하는 방법으로 개발되고 있다. 이와 같은 소프트웨어에서 부대의 과업을 달성하기 위해 사용자의 관여 없이 부대구성원(부대원 또는 예하부대)의 전술적 행위(협업)를 모의하는 기술은 대규모의 군사 모의를 가능하게 하는 중요한 기술 중 하나이다. 부대 구성원의 협업을 모델링하고 구현하는 기술은 사용자(모의 부대장)로 하여금 부대구성원의 세부적인 제어를 요구하지 않고 자신이 제어하는 부대에 할당된 임무 달성에 집중시키는 등의 이점을 제공한다. 본 연구를 통해 우리는 군 도메인에서 사용하고 있는 OneSAF와 FLAMES, VR-Forces 등의 컴포넌트 기반의 모의 소프트웨어를 분석하고, 이들 소프트웨어에서 협업 모델의 위치를 설명한다. 다음으로 역할 개념을 기반으로 부대구성원들의 협업 모델을 제안한다. 본 연구에서는 프로토타입의 개발을 통해 제안 모델의 적용 가능성을 검증한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.527-530
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• 2000

최근의 소프트웨어 위기를 해결할 수 있는 최적의 대안으로서 컴포넌트 기술을 개발, 산업계에 확산하기 위하여 다양한 영역의 비즈니스 컴포넌트를 개발 보급하여야 한다. 비즈니스 컴포넌트를 개발하기 위하여는 컴포넌트의 조립 모델을 정의한 개념적 아키텍쳐를 우선적으로 설정하여야하며 이 모델에 기반한 체계화된 명세 방법을 정의하여 각 컴포넌트가 일관적 체계에 따라 명세화되어 개발할 수 있는 체계를 구축하여야 한다. 본 연구에서는 정통부 사업의 일환으로 수행된 공용 컴포넌트 뱅크 구축을 위한 영역 아키텍쳐 모델을 제시하고, 컴포넌트 뱅크에 구축할 컴포넌트 개발을 위한 명세 방법의 개념 모델과 명세 단계를 제시하고 이를 비즈니스 응용 영역에 적용하여 개발한 명세화 접근 방법 및 개발 결과에 대하여 논한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.2
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• pp.251-256
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• 2006

In this paper we consider multi-stage, multi-product production, inventory systems which have assembly-tree-structure. We propose a new mathematical model for pull type ordering systems based on JIT manufacturing systems. To apply the model to an actual automobile parts manufacturer, the objective of proposed model is to minimize the sum of inventory and setup costs. Finally, a numerical example and computational results are given to illustrate the proposed model.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.7-20
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• 2017

In this study, effects of grain size distribution on the shear strength and rheological properties are investigated for coarse- and fine-grained soils by using direct shear apparatus. Shear strengths are estimated for fine-grained soils with the maximum particle size of 0.075 mm and coarse-grained soils with the maximum particle size of 0.425 mm and fine contents of 17% prepared at dry and liquid limit states. The direct shear tests are conducted under the relatively slow shear velocity, which corresponds to the reactivated landslide or debris flow after collapse according to the landslide classification. In addition, for the evaluation of rheological properties, residual shear strengths for both fine- and coarsegrained soils prepared under liquid limit states are obtained by multiple reversal shear tests under three shear velocities. From the relationship between residual shear strengths and shear rates, Bingham plastic viscosity and yield stress are estimated. The direct shear tests show that cohesions of fine-grained soil are greater than those of coarse-grained soil at both dry and liquid limit states. However, internal friction angles of fine-grained soil are smaller than those of coarse-grained soil. In case of rheological parameters, the plastic viscosity and yield stress of fine-grained soils are greater than those of coarse-grained soils. This study may be effectively used for the prediction of the reactivated landslide or debris flow after collapse.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.115-124
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• 2003

To guarantee the proper functions of a satellite in the extreme space environment, the several test models are developed generally. There are advantages that the design and the analysis of Flight Model(FM) can be validated through these test models, and the functional reliabilities can be increased by reflecting the modifications on the final design of FM. The integration and test of Structure & Thermal Model(STM) of KOMPSAT, being currently developed, have been completed. In this paper, the processes of design/analysis and integration of the STM propulsion system, one of the KOMPSAT modules, are described.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.642-652
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• 2009

Most of lap jointed aircraft structures encounter the fretting damages, which provoke fretting cracks prematurely and lead to significant reduction of fatigue life. In the case of ageing aircrafts especially, this fretting fatigue problem is a fatal threat for the safety and airworthiness. Recently, as the service life extension program(SLEP) of ageing aircrafts has become a hot issue, the prediction of fretting fatigue life is also indispensable. On these backgrounds, a series of experimental tests of fretting fatigue on bolted lap joint specimens, were performed. And the fretting crack initiation and propagation life of each specimen were evaluated using existing and newly proposed prediction models with the fretting parameters obtained from the FEA results for elasto-plastic contact stress analyses. The validations of prediction models were also discussed, comparing the prediction results with experimental test ones.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.415-422
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• 1994

Recent new town construction project proouced large numbers of apartment houses using precast concrete (P. C.) panels. l'bst construction companies involved in this project put their management focus on to the individual control of P.C. panel producing plants and the job sites. Little attention was paid to the integrated management of the production. transportation. and im;tallation of P. C. panels. Numerous job site delays experienced in the new town project were largely based on the poor coordination between these three key disciplines of the P. C. apartment construction. This stlldy was initiated with an .intention to improve coordination between these disciplines. Activities of these disciplines were identified and related data were gathered. This was performed through the interv:iews with the personnel involved in P. C. constructlon and through the analy::;is of the related documents and publications. Based on this information. the authors are nolol developing a model IoIhich will provide a foundation for opt:iJnal.ly coorc.inated control of the proouction. transportation, and installation of P. C. panels for apartment construction. In this paper. the authors briefly present intermediate results of this study.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.79-87
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• 2017

Korea Aerospace Research Institute has being developed a staged combustion cycle rocket (SCCR) engine with high specific impulse to send a 3-ton class satellite into geostationary orbit while conducted Korean Space Launch Vehicle (KSLV) II project. The SCCR engine is different from the KSLV-II engine, which is open cycle engine using a gas-generator. The SCCR engine with closed cycle is composed of a pre-burner, a turbo pump, and a main combustor. The technology demonstration model (TDM0) was assembled and tested in the 7ton-class engine combustion test facility of Naro Space Center, and the combustion test was successfully conducted. Afterward engine-shaped SCCR engine model (TDM1) is being designed and developed for the next combustion test.

• Journal of the Korean Geotechnical Society
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• v.34 no.11
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• pp.33-41
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• 2018

Soil internal erosion is a phenomenon in which fines attached to the solid skeleton are detached by fluid flow, and this continuous fine migration weakens the hydro-mechanical characteristics of the ground structure. This paper proposed governing equations for fine migration in pore spaces and its related scheme for the numerical analysis. Phase diagram for fine particles includes three different states: detached fines in the liquid phase ($c_e$), attached fines in the solid phase (${\sigma}_a$), and pore-clogged fines in the solid phase (${\sigma}_s$). Numerical formulations for finite element method are developed based on the hydraulic governing equations of pore fluid and fine migration. This study proposed a method of estimating model parameters for fine detachment, attachment, and clogging from 1D erosion experiments. And it proposed an analytical formula for hydraulic permeability function considering fine clogging. Numerical analysis of the previous erosion test developed the numerical scheme and verified the adequacy of fine migration models.