• 정보과학회 논문지
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• 제42권7호
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• pp.823-833
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• 2015

하이브리드 시스템은 연속 시스템과 이산 시스템으로 구성된 동적 시스템이다. 하이브리드 시스템은 자동차, 항공, 군사 방어 등 시스템을 명세 하는데 사용되고 있으며 이를 위해 다양한 모델링 언어와 지원 도구가 개발되고 사용되어 왔다. 제안되어 사용되고 있는 언어와 도구들은 목적에 따라 특정한 특징들을 갖고 있다. 한국전자 통신연구원에서 제안한 하이브리드 시스템 모델링 언어인 ECML (ETRI CPS Modeling Language)은 DEV&DESS (Differential Event and Differential Equation Specified System) 형식론을 CPS (Cyber-Physical System) 환경에 맞게 확장한 언어이며 모델링 및 시뮬레이션을 지원한다. 논문에서는 ECML을 소개하고 정형 정의를 제안한다. 또한 제안된 정의에 따라 간단한 차량 모델을 명세한 사례연구를 수행한다.

• 한국항공우주학회지
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• 제48권2호
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• pp.159-166
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• 2020

본 연구는 복잡한 다수 무인기 시스템을 효율적으로 운용하기 위해 이산 사건 모델 기반의 다수 무인기 이종 임무 할당 기법을 제안한다. 이종 임무의 생성, 임무 할당, 무인기 출동, 임무 수행, 무인기 수리 및 정비에 이르는 무인기의 임무 시작에서 종료까지 일련의 과정을 이산 사건 모델링을 통해 수학적으로 정의하고, 이를 기반으로 주어진 임무 상황에서 필요한 최적 무인기 대수를 도출한다. 도출된 최적 무인기 대수를 적용하여 이산 사건 모델 기반의 반복 시뮬레이션을 통해 그 결과를 검증한다. 제안된 이종 임무 할당 기법으로 운용자는 제한된 무인기 자원을 효율적으로 활용하여 주어진 임무 상황에서 최적의 임무 계획을 수립할 수 있다.

• 한국군사과학기술학회지
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• 제9권3호
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• pp.25-32
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• 2006

Weapon systems composed of several subsystems execute various engagement missions in distributed combat environments in cooperation with a large number of subordinate/adjacent weapon systems as well as higher echelons through tactical data links. Such distributed weapon systems require distributed real-time simulation test beds to integrate and test their operational software, analyze their performance and effects of cooperated engagement, and validate their requirement specifications. These demands present significant challenges in terms of real-time constraints, time synchronization, complexity and development cost of an engagement simulation test bed, thus necessitate the use of high-performance distributed real-time simulation architectures, and modeling and simulation techniques. In this paper, in order to meet these demands, we presented a distributed real-time simulation system based on High Level Architecture(HLA) and Discrete Event System Specification(DEVS). We validated its performance by using it as a test bed for developing the Engagement Control System(ECS) of a surface-to-air missile system. The proposed technique can be employed to design a prototype or model of engagement-level distributed real-time simulation systems.

• 한국시뮬레이션학회논문지
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• 제14권2호
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• pp.57-71
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• 2005

A simulation for the analysis of the evasive capability of a conventional costal submarine against a light Anti-Submarine Warfare (ASW) torpedo has been studied. The Torpedo, Submarine Controller, Devoy, and Jammer models of this simulation are analysised and designed using Unified Modeling Language (UML) and in addition they are modeled Discrete Event System Specification (DEVS). We examine maximum speed, acceleration, countermeasure systems capabilities of a submarine, and sonar range of a torpedo as the factors which affect the evasive capability of the submarine. This paper shows the relationships between those various factors and the submarine's evasive capability as the outcome of the simulation. The simulation models can be applied for simulation based acquisition (SBA) of a submarine system.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.415-424
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• 1995

Combined models, specified by two or more modeling formalisms, can represent a wide variety of complex systems. This paper describes a methodology for the development of combined models in two model types of discrete event and continuous process. The methodology is based on transformation of continuous state space into discrete one to homomorphically represent dynamics of continuous processes in discrete events. This paper proposes a formal structure which can combine model of the DES and the CS within a framework. The structure employs the DEVS formalism for the DES models and differential or polynomial equations for the CS models. To employ the proposed structure to specify a DEVS/CS combined model, a modeler needs to take the following steps. First, a modeler should identify events in the CS and transform the states of the CS into the DES. Second, a modular employs the formalism to specify the system as the DES. Finally, a moduler developes sub-models for the CS and continguos states of the DES and establishs one-to-one correspondence between the sub-models and such states. The proposed formal structre has been applied to develop a DEVS/CS combined model for the human cardiovascular system. For this, the cardiac cycle is partitioned into a set of phases based on events identified through observation. For each phase, a CS model has been developed and associated with the phase. To validate the DEVS/CS combined model developed, then simulate the model in the DEVSIM + + environment, which is a model simulation results with the results obtained from the CS model simulation using SPICE. The comparison shows that the DEVS/CS combined model adequately represents dynamics of the human heart system at each phase of cardiac cycle.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.812-815
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• 1996

In this paper, we consider the optimal control problem based on Discrete Event Dynamic Systems(DEDS) in the Temporal Logic framework(TLF) which have studied for a convenient modeling technique. The TLF is enhanced with objective functions(event cost indices) and a measurement space is also defined. Our research goal is the design of the optimal controller for DEDSs. This procedure could be guided by the heuristic search methods. For the heuristic search, we suggested the Stochastic Ruler algorithm, instead of the A algorithm with difficulties as following; the uniqueness of solutions, the computational complexity and how to select a heuristic function. This SR algorithm is used for solving the optimal problem. An example is shown to illustrate our results.

• 대한조선학회논문집
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• 제47권4호
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• pp.628-645
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• 2010

To perform the engagement level simulation between the underwater vehicle model and the surface model those are constituted with various systems/ sub-systems, we implemented four different federates as a federation according to the IEEE 1516 HLA (High Level Architecture) protocol that is the international standard in the distributed simulation. Those are CFCS (Command and Fire Control System) federate, motion federate, external entities (torpedos, countermeasure and surfaceship) federate, and visualization federate that interacts with OSG (Open Scene Graph)-based visualization rendering module. In this paper, we present the detailed method about the model constitution for discrete event simulation in the distributed environment. For the sake of this purpose, we introduce the DEVS (Discrete Event System Specification)-HLA-based modeling method of the CFCS federate that reflects not only the interations between models, but also commands from user and tactics manager that is separated from the model. The CFCS federate makes decisions in various missions such as the normal diving, the barrier misision, the target motion analysis, the torpedo launch, and the torpedo evasion. In the perspective of DEVS modeling, the CFCS federate is the coupled model that has the tactical data process model, command model and fire control model as an atomic model. The message passing and time synchronization with other three federates are settled by the $m\ddot{a}k$ RTI (Runtime Infrastructure) that supports IEEE 1516. In this paper, we provides the detailed modeling method of the complicated model that has hierarchical relationship such as the CFCS system in the submarine and that satisfies both of DEVS modeling method for the discrete event simulation and HLA modeling method for the distributed simulation.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1999년도 추계공동학술대회 논문집:21세기지식경영과 정보기술
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• pp.759-768
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• 1999

In this paper, we developed a simulation model of a car parts assembly line to improve the system performance such as worker's utilization balancing, productivity. This simulation model has been developed using QUEST, a true 3D discrete event simulation pakcage that is designed for modeling and analysis of manufacturing systems. We have suggested the results obtained to improve the system performances of an existing production line.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.543-547
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• 2004

본 연구에서는 현재의 그래픽 시뮬레이션 시스템의 한계를 파악하기 위한 노력으로서 그래픽 시뮬레이션 시스템을 이용한 건설 프로세스 시뮬레이션 결과의 시각화와 장비 운용의 사실적 묘사를 위한 물리적 모델링에 관해서 다루었다. 비정형 물체를 다루는 공사인 토공작업에 대한 시각화를 위하여서 건설공사에 주로 사용되는 수학/통계적 시뮬레이션인 불연속사건 시뮬레이션(Discrete Event Simulation) 프로그램의 출력을 분석하여 작업시간, 대기시간, 운반물량 등에 대한 수치적 결과가 건설작업의 3차원 그래픽 시각화로 표현될 수 있도록 장비, 자재, 작업환경에 대한 객체지향 모델을 설계하였다. 또한 그래픽 시뮬레이션을 통해서 시공과정을 현실과 보다 유사하게 표현하기 위한 일환으로서, 물리적 특성을 고려하여야만 합리적으로 묘사할 수 있는 대표적 장비운용 특성인 크레인 붐(Boom)을 움직였을 때 나타나는 케이블과 자재의 추진동에 관한 물리적 모델링을 수행하여 건설 그래픽 시뮬레이션 시스템의 유용도를 제고하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 춘계학술대회
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• pp.87-91
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• 1995

Combined models, specified by two or more modeling formalisms, can represent a wide variety of complex systems. This paper describes a methodology for the development of combined models in two model types of discrete events and continuous process. The methodology is based on transformation of continuous state space into discrete one to homomorphically represent dynamics of continuous processes in discrete events. As an example, a combined model of human heart is developed which Incorporates conventional differential equation formalism with Zeigler's DEVS(Discrete Event Specification System) [4]formalism.