• Title/Summary/Keyword: DEVS formalism

Search Result 119, Processing Time 0.034 seconds

An Internet Topology Generator Applying DEVS Modeling (DEVS 모델링을 적용한 인터넷 위상 생성기)

  • Sohn Juhang;Park Sangjoon;Han Jungahn;Kim Hyungjong;;Kim Byunggi
    • Journal of the Korea Society for Simulation
    • /
    • v.13 no.3
    • /
    • pp.43-54
    • /
    • 2004
  • Studies of Internet algorithms or policies require experiments on the real large-scale networks. But practical problems with large real networks make them difficult. Instead many researchers use simulations on the Internet topology models. So, It is Important that study about topology model that reflect characteristic of the internet exactly. We propose new topology model which reflect of hierarchical network and addition, removal of nodes and accompanied change of topologies. In the modeling scheme for network generation, we applied DEVS formalism and analyzed the topologies generated by our algorithms.

  • PDF

Using the DEVS formalism for evaluating logistics system performance (DEVS 형식론을 이용한 물류 시스템의 성능 측정)

  • 조병헌
    • Proceedings of the Korea Society for Simulation Conference
    • /
    • 1999.04a
    • /
    • pp.179-183
    • /
    • 1999
  • 최근 기업활동의 일부로서 물류의 중요성이 급속히 부각되고 있고, 물류의 전략 개발과 모델링 방면에서 많은 연구가 진행되었다. 본 논문에서는 이산 사건 시스템을 기술하는 언어인 DEVS 형식론을 이용하여 물류 시스템의 성능을 측정하는 시뮬레이터를 구현한다. 본 논문의 대상 시스템은 다수의 차량을 이용하여 다수의 창고에서 다종의 물건들을 다수의 판매처로 운송하는 시스템이다. 각각의 창고에서는 판매처에서 요구한 물건들을 적재하여 판매처에서는 원하는 물건들을 하차하고 정해진 시간 내에 배달되는지를 검증한다. 모델링된 시스템을 시뮬레이션화하기 위해 DEVSim++를 이용한다. DEVSim++는 DEVS 형식론을 C++ 언어로 표현한 것이다. 여러 가상의 데이터로 시뮬레이션한 결과 적절히 동작하는 것을 알 수 있었다. 향후 모델을 확장해서 전국적인 규모에서 시뮬레이션할 수 있는 무류 시뮬레이터를 구현하면 물류 관련 업무에서 필수적으로 쓰일 도구가 될 것이다.

  • PDF

Simulation of a Dynamic Scheduling Elevator System using the DEVS formalism (DEVS 형식론을 이용한 동적 스케쥴링 승강기 시뮬레이터의 구현)

  • 권성환
    • Proceedings of the Korea Society for Simulation Conference
    • /
    • 1999.10a
    • /
    • pp.163-168
    • /
    • 1999
  • 본 논문에서는 다수의 승강기들이 서로 협력하여 운영되는 대형 고층 빌딩의 승강기 시스템에 대해서 DEVS 형식론을 이용하여 모델링하고 시뮬레이션한다. 다수의 독립적으로 운영되는 승강기로 이루어진 기존의 승강기 시스템과는 달리, 제안된 시스템에서는 사용자의 요구에 따라 승강기의 스케쥴이 생성, 변경, 삭제되는 동적 스케쥴링 기능을 갖도록 하였다. 제안된 시스템은 승강기 시스템을 나타내는 ELEVATOR 모델과 시뮬레이션 수행에 필요한 실험장치인 EF 모델로 구성된다. ELEVATOR 모델은 빌딩을 나타내는 BUILD 모델, 승강기를 나타내는 ELEV 모델과 각 승가기의 스케쥴을 다이나믹하게 제어하는 SCHED 모델로 구성된다. EF 모델은 실험용 데이터를 생성하는 GENR 모델, 이동하는 승객의 데이터를 추적하고 결과를 수집하는 TRANSD 모델로 구성된다. 모델링된 시스템의 시뮬레이션을 위해 DEVSim++를 이용하여 구현하였다. DEVSim++는 DEVS 형식론을 C++로 구현한 것이다. 시뮬레이션을 통하여 제안된 시스템의 효율, 수행 시간을 기존의 승강기 시스템과 비교, 분석하였다.

  • PDF

Embodimenet of Storage Server Program using Multi-threaded Software Development Process based on DEVS formalism (DEVS 형식론 기반 멀티쓰레드 소프트웨어 개발 방법을 이용한 스토리지 서버 프로그램 구현)

  • Im, Jung-Hyun;Oh, Ha-Ryoung;Soong, Yeong-Rak
    • Annual Conference of KIPS
    • /
    • 2015.04a
    • /
    • pp.544-545
    • /
    • 2015
  • 최근 스토리지 서버에 사용되는 코어가 싱글코어에서 점차 발전하여 멀티코어가 됨에 따라 스토리지 서버에 많은 기능들이 추가되었다. 이러한 기능들을 효과적으로 사용하기 위해서는 스토리지 서버를 효율적으로 관리하는 프로그램이 필요하다. 이에 멀티코어를 효과적으로 사용하여 스토리지 서버를 효율적으로 관리할 수 있도록 멀티쓰레드 프로그램으로 스토리지 서버 프로그램을 구현하였다. 멀티쓰레드 소프트웨어는 동시 동작으로 인해 개발하는데 어려움이 있으므로 이를 해결코자 DEVS 형식론 기반의 멀티쓰레드 소프트웨어 개발 방법을 이용하였다. DEVS 형식론 기반의 모델링과 시뮬레이션을 거치고 소프트웨어를 구현하여 개발의 어려움과 검증에 대한 부분을 해결하였다.

A DEVS-based Modeling & Simulation Methodology of Enabling Node Mobility for Ad Hoc Network (노드 이동성을 고려한 애드 혹 네트워크의 이산 사건 시스템 기반 모델링 및 시뮬레이션 방법론)

  • Song, Sang-Bok;Lee, Kyou-Ho
    • Journal of the Korea Society for Simulation
    • /
    • v.18 no.4
    • /
    • pp.127-136
    • /
    • 2009
  • Modeling and Simulation, especially in mobile ad hoc network(MANET), are the most effective way to analyze performance or optimize system parameters without establishing real network environment. Focusing mainly on overall network behaviors in MANET concerns dynamics of network transport operations, which can efficiently be characterized with event based system states rather than execution details of protocols. We thus consider the network as a discrete event system to analyze dynamics of network transport performance. Zeigler's set-theoretic DEVS(Discrete Event Systems Specification) formalism can support specification of a discrete event system in hierarchical, modular manner. The DEVSim++ simulation environment can not only provide a rigorous modeling methodology based on the DEVS formalism but also support modelers to develop discrete event models using the hierarchical composition methodology in object-orientation. This environment however hardly supports to specify connection paths of network nodes, which are continuously altered due to mobility of nodes. This paper proposes a DEVS-based modeling and simulation methodology of enabling node mobility, and develops DEVS models for the mobile ad hoc network. We also simulate developed models with the DEVSim++ engine to verify the proposal.

Verification of Automatic PAR Control System using DEVS Formalism (DEVS 형식론을 이용한 공항 PAR 관제 시스템 자동화 방안 검증)

  • Sung, Chang-ho;Koo, Jung;Kim, Tag-Gon;Kim, Ki-Hyung
    • Journal of the Korea Society for Simulation
    • /
    • v.21 no.3
    • /
    • pp.1-9
    • /
    • 2012
  • This paper proposes automatic precision approach radar (PAR) control system using digital signal to increase the safety of aircraft, and discrete event systems specification (DEVS) methodology is utilized to verify the proposed system. Traditionally, a landing aircraft is controlled by the human voice of a final approach controller. However, the voice information can be missed during transmission, and pilots may also act improperly because of incorrectness of auditory signals. The proposed system enables the stable operation of the aircraft, regardless of the pilot's capability. Communicating DEVS (C-DEVS) is used to analyze and verify the behavior of the proposed system. A composed C-DEVS atomic model has overall composed discrete state sets of models, and the state sequence acquired through full state search is utilized to verify the safeness and the liveness of a system behavior. The C-DEVS model of the proposed system shows the same behavior with the traditional PAR control system.

Design of a Multi-Thread Architecture for an LLRP Server (LLRP(Low Level Reader Protocol) 서버를 위한 멀티쓰레드 구조의 설계)

  • Lee, Tae-Young;Kim, Yun-Ho;Seong, Yeong-Rak;Oh, Ha-Ryoung
    • The KIPS Transactions:PartA
    • /
    • v.19A no.2
    • /
    • pp.93-100
    • /
    • 2012
  • LLRP (Low-Level Reader Protocol) specifies an interface between RFID readers and RFID applications, also called LLRP servers and clients respectively. An LLRP server should concurrently execute various functions. This paper designs an LLRP server of a multi-threaded architecture. For that, (i) the operational procedure between LLRP servers and clients is investigated, (ii) the functional requirements of LLRP servers are presented, (iii) the operation of an LLRP server is decomposed into several threads to satisfy those functional requirements, and (iv) the operational procedure is further examined in thread-level. To validate the designed architecture, it is modeled and simulated by using the DEVS formalism which specifies discrete event systems in a hierarchical, modular manner. From the simulation result, we can conclude that the proposed architecture conforms the LLRP standard and satisfies all the given functional requirements.

Method for Analysis of C3 System of Systems Using Transformation of Federation Based on an Extended DEVS Formalism (확장된 DEVS 형식론 기반 페더레이션의 변환을 통한 C3 복합 체계의 분석 방법)

  • Kang, Bong Gu;Kim, Tag Gon
    • Journal of the Korea Society for Simulation
    • /
    • v.27 no.3
    • /
    • pp.13-21
    • /
    • 2018
  • The system of systems (SoS) based analysis method for the C3 system consisting of the communication system and the command and control (C2) system has the advantage that detailed analysis is possible, but it requires long execution time per one trial, which makes the analysis of various scenarios difficult. To solve this problem, this paper proposes a method for analysis of C3 SoS using a transformation of a federation into an integrated simulation. This transformation technique reduces the execution time while maintaining accuracy by abstracting the system other than the one to be analyzed, consisting of model hypothesis and function identification. The former can construct an abstracted model for the simulation through the proposed extended Discrete Event Systems Specification (DEVS) formalism and the latter can express the characteristics of the model influenced by other systems. From the case study on C and C2 analysis, the experimental results show that this method shortened the time considerably while maintaining the accuracy within an acceptable error range and we expect that this method will enable the exploratory analysis of the complex systems other than C3.

Vessel and Navigation Modeling and Simulation based on DEVS Formalism : Design for Navigation Simulation Architecture with Modeling for Critical Systems and Agents of Vessel (DEVS 형식론 기반의 선박 항해 모델링 및 시뮬레이션 (I) : 항해 시뮬레이션 아키텍처 설계와 선박 핵심 장비 및 에이전트 모델링)

  • Woo, Sang-Min;Lee, Jang-Se;Hwang, Hun-Gyu
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.23 no.9
    • /
    • pp.1038-1048
    • /
    • 2019
  • Recently, various systems have been developed to support ship navigation safety. In order to verify the usefulness of such a system, it is most ideal to try it on a real vessel, but there are many difficulties. As an alternative, usability verification methods applied with modelling and simulation (M&S) techniques are required such as FMSS, which is closest to reality, is very expansive to construct, and there needs the specialized operator. For this reason, this paper proposes a method to verify the navigation safety support system by modeling and simulation techniques based on the Discrete Event System Specification (DEVS) formalism. As a first step, we designed the navigation simulation architecture based on the SES/MB framework, and details on modelling ship core equipment and navigator agents based on the DEVS. Through this, we are able to implement the navigation simulation system for vessels, and evaluate the effectiveness of navigation safety support elements such as collision avoidance, etc. using developed scenarios.

Gun-oriented Engagement Simulation System (함포교전 시뮬레이션 시스템)

  • Lee, Dong-Hoon;Kim, Cheol-Ho;Kim, Tae-Su
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.10 no.1
    • /
    • pp.78-85
    • /
    • 2007
  • A gun is still one of the major weapons of a combat ship. To assess the ship's fire control capability which is influenced by tracking system, fire control algorithm, gun, the ship itself, target behavior, environment and engagement situation, simulation system for gun-oriented engagement for surface ship is needed. This paper proposes the process for designing and implementing a gun-oriented engagement simulation system using DEVS(Discrete Event Simulation Specification), which is a formalism based on the set theory. It consists of the following activities : 1) analyzing the characteristics of a gun-oriented engagement, 2) constructing the deterministic model of the combat ship of study with DEVS, 3) modeling properties of each entity showing as stochastic errors. With this process, the gun-oriented engagement simulation system is developed and applied for the combat system under development.