• Journal of the Korea Society for Simulation
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• v.13 no.2
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• pp.23-34
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• 2004

Regenerative simulation (RS) is a method of stochastic steady-state simulation in which output data are collected and analysed within regenerative cycles (RCs). Since data collected during consecutive RCs are independent and identically distributed, there is no problem with the initial transient period in simulated processes, which is a perennial issue of concern in all other types of steady-state simulation. In this paper, we address the issue of experimental analysis of the quality of sequential regenerative simulation in the sense of the coverage of the final confidence intervals of mean values. The ultimate purpose of this study is to determine the best version of RS to be implemented in Akaroa2 [1], a fully automated controller of distributed stochastic simulation in LAN environments.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.418-424
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• 2013

Both simulation and physical implementation are valuable tasks in sensor network routing protocols. In this paper, we propose an efficient underground utilities monitoring method within several constraints using wireless sensor network. First, in order to physically implement protocol of network which is applied, the distributed event-based simulation, which applies an existing nesC codes of sensor network routing protocols, is implemented and analyzed. Also, we have performed the simulation and analyzed the execution results for application model of routing protocols for monitoring underground utilities in the VIPTOS(Visual Ptolemy and TinyOS) environments which combine TOSSIM and Ptolemy II based on distributed event.

• The Journal of Bigdata
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• v.4 no.2
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• pp.73-83
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• 2019

Since the emergence of the fourth industrial revolution, data analysis is being conducted in various fields. Distributed data processing has already become essential for the fast processing of large amounts of data. However, in the defense sector, simulation used cannot fully utilize the unstructured data which are prevailing at real environments. In this study, we propose a distributed data processing platform that can be applied to battalion level simulation models to provide visualized data for command decisions during training. 500,000 data points of strategic game were analyzed. Considering the winning factors in the data, variance processing was conducted to analyze the data for the top 10% teams. With the increase in the number of nodes, the model becomes scalable.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.9
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• pp.2194-2212
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• 2013

The multicast routing architectures have become indispensable due to the increasing needs for extreme communication services anywhere and anytime. The most recent approaches are called hierarchical and fully distributed, what have been proposed by O. Said et al. in a previous work. These proposed architectures were introduced to enhance the service-centric approach. In this paper, NS2 is used to build a simulation environment to test the hierarchical and the fully distributed multicast architectures as regards the service-centric one. The results of simulation show that the performance of the hierarchical and the fully distributed architectures outperforms the service-centric architecture. Furthermore, the fully distributed architecture is found to have the best performance.

• Journal of the Korea Society for Simulation
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• v.8 no.4
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• pp.9-24
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• 1999

We describe a heterogeneous simulation framework, so called DEVS-HLA, in which conventional simulation models and the DEVS (Discrete Event System Specification) models are interoperable. DEVS-HLA conceptually consists of three layers: model layer, DEVS BUS layer, and HLA (High Level Architecture) layer. The model layer has a collection of heterogeneous simulation models, such as DEVS, CSIM, SLAM, and so on, to represent various aspects of a complex system. The DEVS BUS layer provides a virtual software bus, DEVS BUS, so that such simulation models can communicate with each other. Finally, the HLA layer is employed as a communication infrastructure, which supports several good features for distributed simulation. The DEVS BUS has been implemented on the HLA/RTI (Run-Time Infrastructure) and a simple example of a flexible manufacturing system has been developed to validate the DEVS-HLA.

• ETRI Journal
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• v.44 no.2
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• pp.313-326
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• 2022

This study presents a noble scheme for distributed and parallel simulations with optimized agent placement for simulation instances. The traditional parallel simulation has some limitations in that it does not provide sufficient performance even though using multiple resources. The main reason for this discrepancy is that supporting parallelism inevitably requires additional costs in addition to the base simulation cost. We present a comprehensive study of parallel simulation architectures, execution flows, and characteristics. Then, we identify critical challenges for optimizing large simulations for parallel instances. Based on our cost-benefit analysis, we propose a novel approach to overcome the performance constraints of agent-based parallel simulations. We also propose a solution for eliminating the synchronizing cost among local instances. Our method ensures balanced performance through optimal deployment of agents to local instances and an adaptive agent placement scheme according to the simulation load. Additionally, our empirical evaluation reveals that the proposed model achieves better performance than conventional methods under several conditions.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.171-173
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• 2002

This paper presents a power system decomposition technique for digital simulation of large power system. To decompose power system, distributed transmission line model is used. But this model can be used only for long transmission lines. In this paper, capacitor compensation method is proposed to use distributed transmission line model for short transmission line. And case study shows proposed method can be used for effective power system decompositon in digital simulation of large power system.

• Journal of Korean Institute of Industrial Engineers
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• v.18 no.2
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• pp.31-42
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• 1992

This paper introduces a distuibuted simulation scheme that is useful in the top-down FMS building approach. In the scheme, we first introduce "FMS Shell" that contains basic functions and structure of FMS's. To test a proposed FMS, appropriate features of the proposed FMS are added to the shell, then distributed simulation is performed with the resulting software. This runs like a real system only without hardware devices. An real application case is stated at later part of this paper.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.69-76
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• 2015

Modern warfare, which adopt an intensive technique of applied sciences, is difficult to predict, and has a high complexity. Thus, it is necessary to build a battle-field environment and simulation-based analysis. Various organizations are participated to build battlefield model for defense M&S according to a scale and format. On the basis of this trend, approaching from various systems is needed to reconfigure battlefield modeling for distributed system. This paper proposes building design for battlefield simulation environment with a sample of one-to-one single unit engagement model. The proposed method can expect to utilize an example of distributed environment for various participants that are involved in battlefield modeling and simulation.

• Journal of the Korea Society for Simulation
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• v.5 no.2
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• pp.41-58
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• 1996

The Discrete Event Systems Specification(DEVS) formalism specifies a discrete event system in a hierarchical, modular form. This paper presents a distributed simulation environment D-DEVSim++ for models specified by the DEVS formalism. D-DEVSim++ employs a new simulation scheme which is a hybrid algorithm of the hierarchical simulation and Time Warp mechanisms. The scheme can utilize both the hierarchical scheduling parallelism and the inherent parallelism of DEVS models. This hierarchical scheduling parallelism is investigated through analysis. Performance of the proposed methodology is evaluated through benchmark simulation on a 5-dimensional hypercube parallel machine. The performance results indicate that the methodology can achieve significant speedup. Also, it is shown that the analyzed speedup for the hierarchical scheduling time corresponds the experiment.