• 한국시뮬레이션학회논문지
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• 제8권4호
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• pp.109-124
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• 1999

The major objective of this research is to design and build the variable structure DEVS modeling & simulation framework. To do this, we have proposed the direct message passing mechanism between the model and its simulator to deal with the structural demand from the model during the simulation. In this approach, four types of basic messages are introduced for the vertical(creation/deletion of the child) and horizontal(creation/deletion of the brother) structural changes. Proposed methodology has been successfully applied to the multi-processor system and the forest fire information system.

• 에너지공학
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• 제25권1호
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• pp.108-112
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• 2016

본 연구에서는 국내 원전 산업의 데이터 기반 설계기법 전환을 위하여 관련 문헌을 조사하고 데이터 기반 설계기술에 대한 개념을 정립하였다. 또한 국내외 원전 산업 기술동향 분석을 통해 데이터 기반 설계통합시스템 Framework 개발 및 관련 주요기능을 도출하였다. 국내 원전 건설 시 최신 설계통합시스템 적용에 따라 이를 활용하는 제작사, 시공사 및 발주자의 업무수행 방식 또한 전면적인 전환을 위한 원전 건설단계별 업무프로세스 개선방향을 도출하였다. 이는 기자재 3D 모델 통합, 3D CAD 모델생성, 시공검토 Simulation 등 모델기반 현장설계 수행이 가능하며, 현장설계에서 발생하는 모든 설계도면 및 관련 정보가 데이터 기반 3D CAD 시스템으로 통합관리가 가능하여 이를 운영단계에 이관하여 O&M 단계에서 데이터 기반 운영체계가 가능함에 따라 발전소 안전 운영에 향상이 기대된다.

• 해양환경안전학회지
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• 제23권2호
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• pp.146-152
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• 2017

본 논문은 시뮬레이터 시스템이 가지는 복잡성과 확장성 문제를 해결하기 위한 방법으로 웹 기술을 이용한 선박운항 시뮬레이터 프레임워크를 제안한다. 기존 시뮬레이터 시스템의 필수 기능을 분석하고, 이를 대체할 수 있는 웹 기반 기술을 선별하여 프레임워크를 구성하였다. 또한, 이를 바탕으로 서버와 클라이언트 핵심 기술을 구현하였으며, 이를 통합하여 웹 브라우저를 통해 사용이 가능한 선박운항 시뮬레이터 시스템의 시작품을 제작하였다. 제작된 시작품은 시험평가를 통해 시간과 장소의 제약을 받지 않고 다수의 사용자가 동시에 시뮬레이션 서비스를 이용할 수 있음을 확인하였으며, 향후 다양한 시뮬레이션 분야에 적용될 수 있기를 기대한다.

• Steel and Composite Structures
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• 제10권2호
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• pp.129-149
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• 2010

The objective of this study is to formulate a general 3D material-structural analysis framework for the thermomechanical behavior of steel-concrete structures in a fire environment. The proposed analysis framework consists of three sequential modeling parts: fire dynamics simulation, heat transfer analysis, and a thermomechanical stress analysis of the structure. The first modeling part consists of applying the NIST (National Institute of Standards and Technology) Fire Dynamics Simulator (FDS) where coupled CFD (Computational Fluid Dynamics) with thermodynamics are combined to realistically model the fire progression within the steel-concrete structure. The goal is to generate the spatial-temporal (ST) solution variables (temperature, heat flux) on the surfaces of the structure. The FDS-ST solutions are generated in a discrete form. Continuous FDS-ST approximations are then developed to represent the temperature or heat-flux at any given time or point within the structure. An extensive numerical study is carried out to examine the best ST approximation functions that strike a balance between accuracy and simplicity. The second modeling part consists of a finite-element (FE) transient heat analysis of the structure using the continuous FDS-ST surface variables as prescribed thermal boundary conditions. The third modeling part is a thermomechanical FE structural analysis using both nonlinear material and geometry. The temperature history from the second modeling part is used at all nodal points. The ABAQUS (2003) FE code is used with external user subroutines for the second and third simulation parts in order to describe the specific heat temperature nonlinear dependency that drastically affects the transient thermal solution especially for concrete materials. User subroutines are also developed to apply the continuous FDS-ST surface nodal boundary conditions in the transient heat FE analysis. The proposed modeling framework is applied to predict the temperature and deflection of the well-documented third Cardington fire test.

• 한국항행학회논문지
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• 제25권5호
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• pp.336-343
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• 2021

항공전자시스템은 항공기의 뇌와 신경, 오감에 해당하는 것으로 비행 및 임무를 수행하기 위해 통신/식별/항법/무장/시현 계통의 항공기 탑재 전자장비로 구성된다. 비행체 체계에서의 비중이 50%에 육박하며, 4차 산업혁명 기반 기술이 발전됨에 따라 중요도 및 비중이 증가되는 추세이다. 항공기의 개발 소요시기에 따라 개발 기간은 점점 단축되고 있으며 항공전자시스템 통합 및 검증을 위한 안정적인 항공용 SIL의 적기 개발이 반드시 필요하다. 본 논문에서는 기존 항공용 SIL을 프레임워크 기반의 항공용 SIL로 대체하기 위한 방안을 제안한다. 그리고 대체 적용한 결과를 바탕으로 항공용 시뮬레이션 모델 프레임워크의 성능을 평가한다.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.14-23
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• 2017

In high-density high-rise cities such as Hong Kong, buildings account for nearly 90% of energy consumption and 61% of carbon emissions. Therefore, it is important to study the design of buildings, especially high-rise buildings, to achieve lower carbon emissions in the city. The carbon emissions of a building consist of embodied carbon from the production of construction materials and operational carbon from energy consumption during daily operation (e.g., air-conditioning and lighting). An integrated analysis of both types of carbon emissions can strengthen the design of low carbon buildings, but most of the previous studies concentrated mainly on either embodied or operational carbon. Therefore, the primary objective of this study is to develop a holistic methodology framework considering both embodied and operational carbon, in order to enhance the sustainable design of low carbon high-rise buildings. The framework will be based on the building information modeling (BIM) technology because BIM can be integrated with simulation systems and digital models of different disciplines, thereby enabling a holistic design and assessment of low carbon buildings. Structural analysis program is first coupled with BIM to validate the structural performance of a building design. The amounts of construction materials and embodied carbon are then quantified by a BIM-based program using the Dynamo programming interface. Operational carbon is quantified by energy simulation software based on the green building extensible Markup Language (gbXML) file from BIM. Computational fluid dynamics (CFD) will be applied to analyze the ambient wind effect on indoor temperature and operational carbon. The BIM-based framework serves as a decision support tool to compare and explore more environmentally-sustainable design options to help reduce the carbon emissions in buildings.

• 한국군사과학기술학회지
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• 제17권5호
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• pp.654-662
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• 2014

In the development of the weapon systems, utilization of Modeling & Simulation is growing in every aspect of development process. For the higher utilization of M&S, reuse of the M&S resources is needed to reduce the cost of M&S. I propose the M&S architecture framework that can enhance the reusability of the M&S resources in developing surface-to-air weapon systems. This M&S architecture design framework enables interoperability between the system and sub-systems. In this paper, the advantage and the necessity of the M&S architecture design framework will be described by introducing the cases that the M&S architecture framework reused in the combat experiments, the system development tests, the system operational tests and the concept developments in real projects. These cases will show the high reusability and efficiency of the M&S architecture design framework.

• 한국시뮬레이션학회논문지
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• 제21권1호
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• pp.89-96
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• 2012

최근 모델링 및 시뮬레이션 기술이 다양한 분야에서 활용되고 있으며 특히, 국방 분야에서는 모의기반획득(Simulation Based Acquisition)이 필수적인 정책으로 인식되고 있다. 모의기반획득 과정 중 시험평가 단계에서는 실제 시험이 불가능한 시험평가 환경을 모의하고 실장비 연동검증을 위한 모의 기반 시험환경 구축이 필요하다. 이때 시험평가의 효율성 및 신뢰성향상을 위해 시험평가 장비의 상호운용성, 재사용성 및 신뢰성 확보가 중요하다. 본 연구에서는 지대공 유도무기 체계 시험평가의 효율성을 위해 시뮬레이션 프레임워크 기반 모의기를 제작하였고 시험평가 신뢰성 향상을 위해 VV&A 프로세스를 적용하였다. 지대공유도무기 시험평가를 위한 통합시험시스템의 개발과정 및 특징에 대해 설명하고 실제 시험평가 적용사례 및 결과를 제시하며 향후 활용방안 및 연구방향에 대하여 설명한다.

• Journal of Information Processing Systems
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• 제12권3호
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• pp.538-547
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• 2016

Cloud computing is a new style of computing in which dynamically scalable and reconfigurable resources are provided as a service over the internet. The MapReduce framework is currently the most dominant programming model in cloud computing. It is necessary to protect the integrity of MapReduce data processing services. Malicious workers, who can be divided into collusive workers and non-collusive workers, try to generate bad results in order to attack the cloud computing. So, figuring out how to efficiently detect the malicious workers has been very important, as existing solutions are not effective enough in defeating malicious behavior. In this paper, we propose a security protection framework to detect the malicious workers and ensure computation integrity in the map phase of MapReduce. Our simulation results show that our proposed security protection framework can efficiently detect both collusive and non-collusive workers and guarantee high computation accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권6호
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• pp.1982-2004
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• 2014

Wireless Mesh Networks (WMNs) are emerging as promising, convenient next generation wireless network technology. There is a great need for a secure framework for routing in WMNs and several research studies have proposed secure versions of the default routing protocol of WMNs. In this paper, we propose a security framework for Hybrid Wireless Mesh Protocol (HWMP) in WMNs. Contrary to existing schemes, our proposed framework ensures both end-to-end and point-to-point authentication and integrity to both mutable and non-mutable fields of routing frames by adding message extension fields to the HWMP path selection frame elements. Security analysis and simulation results show that the proposed approach performs significantly well in spite of the cryptographic computations involved in routing.