• Journal of the Korea Society for Simulation
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• v.12 no.3
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• pp.83-94
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• 2003

For 24 hours-7 days service on distributed systems, a great deal of efforts are investigated on high availability for seamless operation. In this paper, we propose a dynamic reconfiguration framework of distributed systems, called "hot-swapping" framework. This framework allows us to upgrade and exchange a number of modules of a distributed system without stopping running service as well as the system itself. In order to hide the state of service operation, the framework employes the "proxy" design pattern. Our framework provides two types of proxies: a static proxy and a dynamic proxy, Static proxies can achieve fast execution time, but they need to be changed whenever any minor change exists in the related swappable module. Meanwhile, dynamic proxies takes longer execution time, but do not need to be changed under minor changes of swappable modules. We compare performances of static and dynamic proxies and also apply the framework to a real situation with security management modules. management modules.

• Journal of the Korea Society for Simulation
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• v.23 no.2
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• pp.57-64
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• 2014

This paper proposes a framework to construct the synthetic battlefield based aviation engagement simulation model for the distributed system. The proposed framework has the synthetic battlefield in the HLA (High Level Architecture)/RTI (Run-Time Infrastructure) based distributed system to reflect environmental effects into the aviation engagement simulation model. In an aviation engagement, the environment affects weapon systems such as detection and movement. Therefore, environmental effects are required to be reflected in the simulation. However, former researches are inadequate for complex operations of weapon systems that are requirements of the engagement simulation. Thus, the construction of the engagement simulation system of which reflects environmental effects based on environmental data is still difficult. The main objective of this paper is to propose a framework to solve the difficulty and constructs an example system based on the proposed framework.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.149-158
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• 2019

This paper introduces an integrated Modeling & Simulation framework for the efficient development of the rescue robot which rescues a wounded patients or soldiers and disposes a dangerous objects or explosive materials in the battlefields and disastrous environments. An integrated M&S(Modeling & Simulation) framework would have enabled us to perform the dynamic simulation program GAZEBO based Software-in-the-Loop Simulation(SILS) which is to replacing the robot platform hardware with a simulation software. An integrated M&S framework would help us to perform designing robot and performance validation of robot control results more efficiently. Furthermore, Tele-operation performance in the unstructured environments could be improved. We review a case study of applying an integrated M&S framework tool in validating performance of mobility stabilization control, one of the most important control strategy in the rescue robot.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.945-946
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• 2011

• Bulletin of the Korean Chemical Society
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• v.19 no.4
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• pp.422-428
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• 1998

In the present paper, we report a molecular dynamics (MD) simulation of non-rigid zeolite-A framework only as the base case for a consistent study of the role of intraframework interaction on several zeolite-A systems using the same technique in our previous studies of rigid zeolite-A frameworks. Usual bond stretching, bond angle bending, torsional rotational, and non-bonded Lennard-Jones and electrostatic interactions are considered as intraframework interaction potentials. The comparison of experimental and calculated structural parameters confirms the validity of our MD simulation for zeolite-A framework. The radial distribution functions of non-rigid zeolite-A framework atoms characterize the vibrational motion of the framework atoms. Mean square displacements are all periodic with a short period of 0.08 ps and a slow change in the amplitude of the vibration with a long period of 0.53 ps. The displacement auto-correlation (DAC) and neighbor-correlation (DNC) functions describe the up-and-down motion of the framework atoms from the center of α-cage and the back-and-forth motion on each ring window from the center of each window. The DAC and DNC functions of the framework atoms from the center of α-cage at the 8-ring windows have the same period of the up-and-down motion, but those functions from the center of 8-ring window at the 8-ring windows are of different periods of the back-and-forth motion.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.509-516
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• 2011

As a high interest in low-carbon transportation, investment of the railway systems has increased. Because the layout of tracks is very complex and the movement pattern of the train is not fixed in the railway depot, there is a need for simulation technology for a more accurate analysis of the railway depot. But most previous researches and commercial simulation tools focused on the main-line. This research suggests the simulation framework for analysis of the railway depot. The simulation framework will help to develop the simulation tools of the railway depot.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.100-114
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• 2007

Decision makers in the service industry must effectively cope with queuing problems, service capacity optimization, service efficiency and service quality problems. This study proposes a computer simulation-enabled MCDM framework that integrates computer simulation analysis, Taguchi method, expert opinion and multiple criteria decision making (MCDM) to assist decision makers in coping with decision problems. In this framework, Taguchi method is adopted to reduce the time required for the simulation experiment. Computer simulation analysis is adopted to obtain useful information for rapid decision-making without interrupting actual production. MCDM is used to select the optimal alternative. The illustrative result is extremely promising.

• Spatial Information Research
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• v.18 no.5
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• pp.119-131
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• 2010

Researchers require repetitive works such as data format analysis, reformatting and map reprojection in order to use geospatial data. To solve above problems, they are building web-based simulation systems with web developers. But the web-based systems are not efficiently developed because there is not the appropriate simulation framework for a web-based system using geospatial data. In this study, the geospatial simulation framework that can be effectively applied to the web-based system was designed and proposed. Also, the framework was composed of 7 modules; web mapping service, GIS mapping, statistics, model, processing,graphics, and geospatial datasets. In order to evaluate the effectiveness of the framework, a case study of urban growth has been verified. Experts who are not specialized in geospatial information disciplines expect to build easily a web-based system using geospatial data.

• Structural Engineering and Mechanics
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• v.30 no.3
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• pp.331-350
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• 2008

A framework for multi-platform analytical and multi-component hybrid (testing-analysis) simulations is described in this paper and illustrated with several application examples. The framework allows the integration of various analytical platforms and geographically distributed experimental facilities into a comprehensive pseudo-dynamic hybrid simulation. The object-oriented architecture of the framework enables easy inclusion of new analysis platforms or experimental models, and the addition of a multitude of auxiliary components, such as data acquisition and camera control. Four application examples are given, namely; (i) multi-platform analysis of a bridge with soil and structural models, (ii) multiplatform, multi-resolution analysis of a high-rise building, (iii) three-site small scale frame hybrid simulation, and (iv) three-site large scale bridge hybrid simulation. These simulations serve as illustrative examples of collaborative research among geographically distributed researchers employing different analysis platforms and testing equipment. The versatility of the framework, ease of including additional modules and the wide application potential demonstrated in the paper provide a rich research environment for structural and geotechnical engineering.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.2
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• pp.189-202
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• 2009

As naval ships become more complex with the reduced cost and time for their development, modeling and simulation are increasingly used. The US navy has being applied the concept of a simulation-based acquisition(SBA) to their acquisition process. However, there have been few studies on a simulation-based acquisition for naval ships (SBA-NS) in the Korean naval shipbuilding. In this paper, we discuss a framework to establish collaborative environment(CE) for an advanced naval ships acquisition based on PLM. For this, we propose architectures and a naval ship information model for design the framework of the SBA-NS. To design the framework, we develop the methodology that is composed of three major processes that are the requirement analysis process, the SBA-NS architectures design process and the design process of a reference model of a naval ship product information. Applying the methodology, the framework suitable for the Korean Navy context is developed.