• 품질경영학회지
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• 제46권4호
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• pp.973-982
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• 2018

Purpose: The purpose of this study is to develop an effective simulation modeling formalism for autonomous control systems, such as unmanned aerial vehicles and unmanned surface vehicles. The proposed simulation modeling formalism can be used to evaluate the quality and effectiveness of autonomous control systems. Methods: The proposed simulation modeling formalism is developed by extending the classic DEVS (Discrete Event Systems Specifications) formalism. The main advantages of the classic DEVS formalism includes its rigorous formal definition as well as its support for the specification of discrete event models in a hierarchical and modular manner. Results: Although the classic DEVS formalism has been a popular modeling tool, it has limitations in describing an autonomous control system which needs to make decisions by its own. As a result, we proposed an extended DEVS formalism which enables the effective description of internal decisions according to its conditional variables. Conclusion: The extended DEVS formalism overcomes the limitations of the classic DEVS formalism, and it can be used for the effectiveness simulation of autonomous weapon systems.

• 한국항만학회지
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• 제14권1호
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• pp.47-55
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• 2000

In order to cope with the changes of container terminal situation in these days, many simulation studies for container terminal have been accomplished. But previous simulation studies using simulation language have limitations in model representation and difficulties in modeling of large scaled container terminal system. To make these problems better, this paper addresses an object-oriented simulation of container terminal system using a DEVS formalism. The DEVS(Discrete Event System Specification) formalism, developed by Zeigler, supports specification of discrete event system in a hierarchical and modular manner. The formalism provides a mathematical basis for studying discrete event systems with better understood and sounder semantics. In a step of system modeling, a DEVS formalism aims at the exact system modeling that has a basis of semantics and utilizing the object-oriented manner can flexibly cope with the changes of system environment. In this study a model is developed and verified through the simulation of some alternatives.

• 한국시뮬레이션학회논문지
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• 제22권1호
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• pp.21-30
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• 2013

하이브리드 시스템은 서로 다른 상태와 시간을 가지는 부 시스템의 조합으로 이루어진다. 대표적인 예가 이산 사건 시스템과 연속 시간 시스템의 조합이다. HDEVS 형식론은 이러한 하이브리드 시스템을 모델링하고 분석하기 위해 제안되었는데, 이러한 형식론을 통해 모델러는 수학적인 형식론에 기초한 계층적이고 모듈성이 있는 모델을 설계할 수 있었다. 그러나 HDEVS 형식론이 주로 분산된 연동 시뮬레이션에 적용되었기 때문에 모델러는 하이브리드 시스템을 연동에 참여할 시뮬레이터에 맞게 서로 다른 모델들로 구분하여 재구성해야 했다. 따라서 모델은 시스템을 그대로 표현하기보다 나누어진 모델들의 연동 구조로 표현되었다. 본 논문은 이러한 문제를 해결하고 통합된 하이브리드 모델을 만들 수 있는 모델링 방법론과 그에 대한 시뮬레이션 방법론을 제안한다. 기존에 연동형 구조에 적용되었던 것과 달리, 하이브리드 시스템은 그 시스템 본래의 형태 그대로 통합된 모델로 모델링 될 수 있다. 또한 이 논문은 제안하는 모델링 방법론에 따르는 시뮬레이션 엔진 구조에 대해서 논하고 물탱크 조절 예제를 통한 간단한 사례 연구도 포함한다.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2002년도 추계학술대회 논문집
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• pp.85-89
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• 2002

Development of distributed simulation environment must be required in order to simulate the distributed models regionally and inter-operate with running simulations individually, Simulation based on DEVS formalism is difficult to simulate the distributed models. DEVS formalism is modeling methodology. To specify model, this formalism separates behavior and structure, therefore it is able to design complex model easily. HLA is standard framework of distribute simulation environment, It is defined to facilitate the interoperability and the reusability. RTI (Run Time Infrastructure) is software that provides common service to simulation systems and implementation of the HLA Interface Specification. Method of implementation is that modules cooperating with RTI are added to simulator on DEVS simulation environment. On the DEVS simulation environment (DEVS-Obj -C) that already developed, Highest class of abstract simulator uses service that RTI provide, then This environment is able to change DEVS model into Federate and run distribute simulation that inter-operates with the RTI. Because this distributed simulation environment includes convenience of modeling that obtains through the DEVS formalism and accompanies HLA standard, this environment make it possible to simulate with_ complex systems and heterogeneous simulations

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1999년도 추계학술대회논문집
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• pp.35-42
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• 1999

In order to cope with the changes of container terminal situation in these days, many simulation studies for container terminal have been accomplished. But established simulation studies using simulation language have restrictions in model representation and difficulties in modeling of large scaled container terminal system. To make these problems better, in this paper addresses object-oriented simulation of container terminal system using a DEVS formalism. In a step of system modeling, using a DEVS formalism aim at the exact system modeling that has a basis of semantics and utilizing the object-oriented manner can flexibly cope with the changes of system environment. In this study a model was developed and verified through the simulation of some alternatives.

• 한국시뮬레이션학회논문지
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• 제11권2호
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• pp.77-88
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• 2002

Petri nets is a widely used formalism for specification and analysis of concurrent systems which is a subclass of discrete event systems. The DEVS (Discrete Event System Specification) formalism provides a general framework for specification of discrete event systems in a hierarchical, modular form. Often, modeling a discrete event system may employ both Petri Nets and DEVS formalism. In such a case low-level operational logics are modeled by Petri Nets and high-level managements by the DEVS formalism. Analysis of the system requires simulation of the overall system. This paper presents an algorithm for transformation of Petri Nets to DEVS formalism. The transformation enables modelers to simulate an overall system, which consists of DEVS models and Petri Nets models, in a unified DEVS simulation environment such as DEVSim++. An example for such transformation will be given.

• 한국시뮬레이션학회논문지
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• 제10권3호
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• pp.1-14
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• 2001

A hybrid system is defined as a mixture of continuous systems and discrete event systems. This paper first proposes a framework for hybrid systems modeling, called Hybrid Discrete Event System Specification (HDEVS) formalism. It then presents a method for simulators interoperation in which a continuous system simulator and a discrete event simulator are executed together in a cooperative manner. The formalism can specify a hybrid system in a way that a continuos system and a discrete event system are separately modeled by their own specification formalisms with a support of well-defined interface. We call such interface an A/E converter for analog-to- event conversion and an E/A converter for event-to-analog conversion. Simulators interoperation is based on the concept of pre-simulation in which simulation time for a continuous simulator is advanced in accordance with a discrete event simulator.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 추계학술대회 논문집
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• pp.24-29
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• 1999

Proposed in this paper is a modeling and simulation methodology for a virtual manufacturing environment. Based on DEVS formalism[Zeigler 76], the proposed model, so called GKDEVS, is designed to descript the geometrical knematic structure as well as event-driven and continuous state dynamics. In terms of abstract simulation algorithm[Zeigler 84], the simulation method of GKDEVS is proposed for combined discrete-continuous simulation. Using the GKDEVS, and FMS model consisting of a turing machine, a 3-axis machine and a RGV-mounted robot is constructed and simulated.

• 대한교통학회지
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• 제14권1호
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• pp.101-116
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• 1996

Increased attention has been paid in recent years to the need of traffic management for alleviating urban traffic congestion. This paper presents a discrete event modeling and simulation framework for analyzing the traffic flow. Traffic simulation models can be classified as being either microscopic and macroscopic models. The discrete event modeling and simulation technique can be basically employed to describe the macroscopic traffic simulation model. To do this, we have employed the System Entity Structure/Model Base (SES/MB) framework which integrates the dynamic-based formalism of simulation with the symbolic formalism of AI. The SES/MB framework supports to hierarchical, modular discrete event modeling and simulation environment. We also adopt the Symbolic DEVS (Discrete Event System Specification) to developed the automated analysis methodology for generating optimal signal light policy. Several simulation tests will demonstrates the techniques.

• 한국시뮬레이션학회논문지
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• 제27권3호
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• pp.37-44
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• 2018

복잡한 이산 사건 동적 시스템을 분석하기 위해 모델링 및 시뮬레이션(M&S) 기법을 적용함에 있어서, 기존에는 사용자 수준에 따라 각기 다른 시뮬레이션 환경을 사용해야 했다. 그에 따른 불편함을 해결하기 위하여 본 논문에서는 사용자 수준에 따라 M&S를 수행할 수 있는 통합된 개발 환경 및 개발 환경에서 모델을 효율적으로 관리하기 위해 정형화된 인터페이스를 제안한다. 인터페이스는 확장된 DEVS 형식론 및 모델 제작 규칙으로 구성되어있다. 개발 환경은 모델링 환경과 시뮬레이션 환경으로 나뉘고, 모델링 환경에서는 사용자의 수준별로 다른 모델링 방식을 제공한다. 모델링 작업의 결과로 생성된 모델을 활용하여 시뮬레이션 환경에서 여러 파라미터를 입력해서 시뮬레이션 함으로써 다양한 경우에 대해서 실험을 할 수 있다. 사례 연구에서는 제안한 M&S 환경을 구현한 내용에 대해 소개하고, 환경을 활용해서 복잡한 국방 전투 시스템을 모델링하고, 만들어진 모델을 바탕으로 시뮬레이션 하는 과정을 소개한다.