• Korean Journal of Computational Design and Engineering
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• v.17 no.1
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• pp.35-44
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• 2012

Many automobile manufacturers are doing experiment on manufacturing environments by using an augmented reality technology. However, system layout and process simulation by using the virtual reality technology have been performed actively more than by using the augmented reality technology in practical use so far. Existing automobile assembly by using the augmented reality requires the precise calibrating work after setting the robot because the existing augmented reality system for the automobile assembly system configuration does not include the end tip deflection and the robot joints deflection due to the heavy weight of product and gripper. Because the robot is used mostly at the automobile assembly, the deflection problem of the robot joint and the product in the existing augmented reality system need to be improved. Moreover camera lens calibration has to be performed precisely to use augmented reality. In order to improve this problem, this paper introduces a method of the software based calibration to apply the augmented reality effectively to the automobile assembly system. On the other hand, the camera lens calibration module and the direct compensation module of the virtual object displacement for the augmented reality were designed and implemented. Furthermore, the developed automobile assembly system oriented AR-system was verified by the practical test.

• Journal of Computing Science and Engineering
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• v.2 no.4
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• pp.375-393
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• 2008

The dynamic cast operation allows flexibility in the design and use of data management facilities in object-oriented programs. Dynamic cast has an important role in the implementation of the Data Management Services (DMS) of the Mission Data System Project (MDS), the Jet Propulsion Laboratory's experimental work for providing a state-based and goal-oriented unified architecture for testing and development of mission software. DMS is responsible for the storage and transport of control and scientific data in a remote autonomous spacecraft. Like similar operators in other languages, the C++ dynamic cast operator does not provide the timing guarantees needed for hard real-time embedded systems. In a recent study, Gibbs and Stroustrup (G&S) devised a dynamic cast implementation strategy that guarantees fast constant-time performance. This paper presents the definition and application of a cosimulation framework to formally verify and evaluate the G&S fast dynamic casting scheme and its applicability in the Mission Data System DMS application. We describe the systematic process of model-based simulation and analysis that has led to performance improvement of the G&S algorithm's heuristics by about a factor of 2. In this work we introduce and apply a library for extracting semantic information from C++ source code that helps us deliver a practical and verifiable implementation of the fast dynamic casting algorithm.

• Water Engineering Research
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• v.1 no.4
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• pp.267-277
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• 2000

This study reports an examination of the sensitivity of water resources in the Keum River basin to climate change. Assuming a doubling in $CO_2$ concentrations, a cooperative study provided four climate change scenarios for this study, which have been translated into temperature and precipitation scenarios on a basin scale. The study utilized these temperature and precipitation data for each climate change scenario as inputs to the NWS-PC model to generate the corresponding streamflow scenario over the Keum River basin. A reservoir simulation model for the Dae-Chung Dam in the Keum River basin has been developed with an object-oriented simulation environment, STELLA. For each streamflow scenario, the performance of the reservoir was assessed in terms of reliability, resiliency, and vulnerability. Although the simulation results are heavily dependent on the choice of the climate change scenarios, the following conclusions can be clearly concluded: (1) the future streamflow over the Dae-Chung Dam tends to decease during the dry period, which seriously increases competitive water use issues and (2) flood control issues predominate under the $2CO_2$-High case.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.11a
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• pp.241-247
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• 2000

날로 복잡해지고 거대해지는 시스템의 추세를 감안할 때 앞으로 시스템 분야의 주요 구성요소간 상호작용을 분석하여 최적의 시스템 운영방안을 도출하기 위해서는 시뮬레이션 기법의 도입이 필수적이다. Simplus 3D는 분석대상 시스템을 주요 객체 단위로 Model 상에 재구성하여 이들의 움직임과 주체적 의사결정 논리를 자체 서술어를 사용하여 묘사하도록 고안된 범용 그래픽 시뮬레이션 소프트웨어로 사용자가 정의한 Logic을 Procedure 또는 Function화하여 별도의 File에 저장하고 재활용 가능하며, 객체별 Logic Trace가 가능하여 객체 시나리오의 상세분석 및 Logic 디버깅이 용이하다. 또한 대상시스템의 특성에 따라 Macro한 수준의 개략적인 묘사부터 Micro한 수준의 제어 알고리듬에 이르기까지 묘사의 수준이 자유롭고, 시뮬레이션에 주로 사용되는 물류설비 및 Logic을 Module로 제공하며 필요시 Custom Logic을 추가할 수 있다. 분포형태는 일양분포, 지수분포, 정규분포 등 다양한 분포형태를 지원하며 9999개까지의 Random Number Seed 지정이 가능하다. 일반 PC에서도 실행 가능하며 3차원 Animation과 다양한 형태의 Report를 제공함으로써 비전문가나 의사결정자가 각종 대안에 대한 시뮬레이션 결과를 시각적으로 확인하여 쉽게 이해할 수 있도록 하였다. Simplus 3D는 현재까지 생산시스템, 항만 및 교통 등의 분야에 광범위하게 활용되고 있으며, 본 논문에서는 기아자동차 WBS 물류시스템 시뮬레이션 모델과 고속도로 톨게이트 시뮬레이션 모델을 활용사례로 소개하고자 한다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.543-547
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• 2004

Visualization of construction process simulation and physical modeling were considered to overcome the limitations of current graphical simulation. The output of discrete-event simulation programs which are the most common mathematical statistical simulation tool for construction processes were analyzed for the visualization of earthmoving process that dealing with objects without fixed. Object-oriented models for equipment, material and work environments were devised to effectively visualize the numerical simulation results of the working time, the queuing time as well as the amount resources etc. The oscillation of the crane's cable and the lifted material that should be considered to rationally modeled and simulated by construction graphical simulation. The derived equation of motion was solved by numerical analysis procedure. Then obtained results was used for physical modeling.

• Journal of the Korea Society for Simulation
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• v.21 no.2
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• pp.31-39
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• 2012

Simulation Framework is a basic software tool used to develop simulation applications. This paper describes the development of a discrete event simulation framework based on DEVS(Discrete EVent System Specification) formalism, using MATLAB language which is widely used in technical computing and engineering disciplines. The newly developed framework utilizing MATLAB object oriented programming combines the convenience of MATLAB language and the sophisticated architecture of the DEVS formalism. Hence, it supports the productivity, flexibility, extensibility that are required for the simulation application software development of the weapon systems engagement. Moreover, it promises a simulation application the increased the computation speed proportional to the number of CPU of a multi-core processor, providing the batch simulation functionality based on MATLAB parallel computing technology.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.29-39
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• 2008

Recently, an ALV (Automated Lifting Vehicle) is studied as an efficient transporter, which can reduce the waiting time during ship operation in a container terminal. There are little of studies on an ALV system considering dynamic factors after analysing the cooperation between equipments. The performance of an ALV depends on self-loading & unloading of an ALV, vehicle’s interference, and occupancy of an available transfer point under dynamic environment. So, it is very difficult to evaluate the productivity of a container terminal with an ALV system. Therefore the simulation model with operational rules that be apt for an ALV system must be developed. Also the model has to consider the characteristics of interface operations and vehicle traffic. Supposing an container terminal with perpendicular layout, this study analyses the process of container handling operation and proposes operational rules such as the ALV dispatching, routing algorithm and so on for a model. We developed a simulation model for a container terminal with an ALV system using object-oriented simulation software, Anylogic.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.258-262
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• 2000

This paper reports on the development of the analysis program of the valve train system, IV-TAP. It is essential to verify the stability of the design and to improve the performance of the system. In order to do that effi챠ently, it is required that integrated and interactive simulation analysis program. IV-TAP is developed in the base of the object-oriented, capsulation, modulization, OLE(objected linking and embedding) and variational design theory. So it contain the expandability and flexibility of the structure. In additon to that, it is programed to make the convenient user interface by using the visualization programming. It can support the modification of the valve element as well as the development of the valve system in the beginning. It is expected to reduce the money and effort for design the valve train system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1279-1288
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• 1999

DEVSim++ is a C++ based, object-oriented modeling/simulation environment which realizes the hierarchical, modular DEVS formalism for discrete event systems specification. The paper describes a methodology for performance modeling and analysis of an ATM-based network system within the DEVSim++ environment. The methodology develops performance models for the system using the DEVS framework and implement the models in C++. Performance indices measured are the length of queues located at connection of the system and cell waiting times with respect to QoS grades for a network bandwidth of 155 Mbps.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.457-459
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• 1998

본 논문에서는 하드웨어-소프트웨어 시스템에서의 시스템 레벨 모델링 및 통합 모의 실험(co-simulation)에 관한 새로운 방법을 다루고 있다. 복잡한 시스템의 하드웨어와 소프트웨어를 하나의 객체 지향 방법론으로 모델링 및 모의 실험하여 빠르고 쉽고 정확하게 시스템의 성능을 예측하고 분석하여, 시스템 설계가 최적화 되도록 도움을 주는 설계 도구를 제안한다. ASIC, 보조 디바이스, 벗, 디스크 및 소프트웨어 등을 객체 지향 모델링 방법인 UML(Unified Modeling Language) 형식론으로 시스템의 구조를 GUI을 사용하여 모델링하고, 이것으로부터 자동적으로 DEVS(Discrete EVent System) 모의 실험 모델을 생성해내어 통합 모의 실험을 수행함으로써 시스템의 성능을 쉽고 빠르게 측정하고 예측하는 방법론을 제시한다. UML과 DEVS는 형식론으로서, UML은 추상화 수준의 시스템 모델링과 그래픽 사용자 인터페이스를 제공하며, 모의 시험은 DEVS의 시뮬레이터인 DEVS++을 사용하였다. DEVS++는 C++ 라이브러리 형태이므로 쉽게 UML에서 DEVS 형식론으로 모의 실험 모델을 추가하여 간단한 모델링할 수 있을 뿐만 아니라 정확한 모의 실험 결과를 얻을 수 있다.