• 한국시뮬레이션학회논문지
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• 제13권2호
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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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• 제37권4호
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• pp.418-424
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• 2013

센서네트워크 라우팅 프로토콜에 있어서 시뮬레이션과 물리적 구현은 모두가 중요한 작업이다. 본 연구에서는 무선센서네트워크를 이용하여 여러 제약조건 내에서 효과적인 지하매설물 감시 방법을 제안한다. 먼저 적용 대상 네트워크의 프로토콜을 물리적으로 구현하기 위해서 센서 네트워크 라우팅 프로토콜의 기존 nesC 코드를 적용하는 분산 이벤트기반 시뮬레이션을 구현하고 분석하였다. 또한, TOSSIM[2]과 분산이벤트 기반의 Ptolemy II를 연동한 VIPTOS(Visual Ptolemy and TinyOS)환경에서 지하 매설물 감시를 위한 라우팅프로토콜 응용모델의 시뮬레이션을 수행하고 실행결과를 분석하였다.

• 한국빅데이터학회지
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• 제4권2호
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• pp.73-83
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• 2019

4차 산업혁명의 기술 등장 이후 대규모 데이터 시대에서 새로운 가치 창출을 위한 데이터 정보 분석은 다양한 분야에서 시도되고 있다. 대용량 데이터를 빠르게 처리하는데 있어서 분산 데이터 처리는 이미 필수적이다. 하지만 아직 국방 분야에서 운용하고 있는 시뮬레이션들은 쌓여 있는 비정형 데이터를 활용할 수 있는 시스템이 미비하다. 이에 본 연구에서는 훈련간 발생하는 문제에 대응하기 위한 지휘결심에 가시화된 데이터를 제공하기 위해서 대대급 규모의 시뮬레이션 모델에 적용 가능한 분산 처리 플랫폼을 제안한다. 전략게임 데이터 50만개를 분석하는 과정으로, 데이터가 가지고 있는 여러 요인들 중 승리요인에 영향을 미치는 요소들을 분석할 수 있게 구현하였다. 결과적으로 상위 10%에 있는 팀들의 데이터를 분석하는 과정에서의 분산처리 사용한 결과를 측정 및 비교 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권9호
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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.

• 한국시뮬레이션학회논문지
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• 제8권4호
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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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• 제44권2호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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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.

• 대한산업공학회지
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• 제18권2호
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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.

• 한국시뮬레이션학회논문지
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• 제24권4호
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• pp.69-76
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• 2015

응용과학이 집약된 현대의 전쟁은 예측하기 어렵고 복잡도가 높아서, 전장 모의환경의 구축과 시뮬레이션 기반 획득을 통한 분석이 필수적이다. 국방 M&S 에서의 전장 모의환경 구축은 그 규모와 형태에 따라 다양한 연구기관이 참여한다. 이러한 추세에 따라, 전장 모의환경의 모델링을 분산 시스템으로 재구성하여 다양한 시스템에서의 접근을 수용할 필요가 있다. 본 논문에서는 분산전장 모의환경 구축 방법을 제안하고 단일부대 1:1 교전모델의 사례를 통해 검증한다. 제안하는 분산전장 모의환경 구축 방법은 다수의 참여자로부터 비롯되는 다양한 시스템 환경에서 전장 모의환경 모델링 및 시뮬레이션을 가능하게 하며, 구축된 분산 환경 또한 구축 예시로서 활용될 것으로 기대한다.

• 한국시뮬레이션학회논문지
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• 제5권2호
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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.