• Title, Summary, Keyword: formalism

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Effective Simulation Modeling Formalism for Autonomous Control Systems (자율제어시스템의 효과적인 시뮬레이션 모델링 형식론)

  • Chang, Dae Soon;Cho, Kang H;Cheon, Sanguk;Lee, Sang Jin;Park, SangChul
    • Journal of the Korean Society for Quality Management
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    • v.46 no.4
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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.

Algorithm for Transformation of Timed Petri Nets to DEVS Formalism (시간 페트리네트를 DEVS 형식론으로 변환하는 알고리즘)

  • 김영찬;김탁곤
    • Journal of the Korea Society for Simulation
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    • v.11 no.2
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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.

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The Aesthetic Values of Formalism Art to Wear (형식주의 예술의상의 미적 가치)

  • 서승미;양숙희
    • The Research Journal of the Costume Culture
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    • v.11 no.1
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    • pp.118-134
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    • 2003
  • The first purpose of this study is to take a better look it the background of Formalism art in the cultural society and to examine the aesthetic value of the formative arts of formalism architecture that are ail basically founded upon the study of Formalism. Secondly, it analyzes the aesthetic value of Formalism Art to Wear, Which can be explained as a mixture of art and fashion, by investigate to the features of art history. The results are as follows; First, Formalism Art to Wear of Simultaneity does not represent continuance but simultaneous. In other words. inside the same time and place of dimension, events art visualized without transformation. Secondly, formalism Art to Wear of Geometrical Aesthetics deals with a purely genuine atmosphere that pursues absolute perfection, composed abstract of geometrical shapes. Thirdly, Fomarlism Art to Wear of Deformation breaks analysis from balance and symmetry showing extreme transformation nil new vitality. Fourthly, Formalism Art to Wear of Space Extension experiments with post-corporeality. Post-corporeality centers the human body extension that is open to various boundaries of implosion and electronic technologies, providing us with a new Cyborg of the digital body.

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Structured DEVS Formalism: A Structural Modelling Method of Discrete Event Systems (Structured DEVS Formalism: 이산사건 시스템의 구조적 모델링 기법)

  • Song, Hae-Sang
    • Journal of the Korea Society for Simulation
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    • v.21 no.2
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    • pp.19-30
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    • 2012
  • In recent decades, it has been known that the Discrete Event System Specification, or DEVS, formalism provides sound semantics to design a modular and hierarchical model of a discrete event system. In spite of this benefit, practitioners have difficulties in applying the semantics to real-world systems modeling because DEVS needs to specify a large size of sets of events and/or states in an unstructured form. To resolve the difficulties, this paper proposes an extension of the DEVS formalism, called the Structured DEVS formalism, with an associated graphical representation, called the DEVS diagram, by means of structural representation of such sets based on closure property of set theory. The proposed formalism is proved to be equivalent to the original DEVS formalism in their model specification, yet the new formalism specifies sets in a structured form with a concept of phases, variables and ports. A simplified example of the structured DEVS with the DEVS diagram shows the effectiveness of the proposed formalism which can be easily implemented in an objected-oriented simulation environment.

Object-Oriented Simulation of Container Terminal using a DEVS Formalism (DEVS 형식론을 이용한 컨테이너터미널의 객체지향 시뮬레이션에 관한 연구)

  • 성경빈;정희균;박용욱;이철영
    • Journal of Korean Port Research
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    • v.14 no.1
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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.

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A Simplified PBM and Application to the Loss Analysis of a Dielectric Optical Waveguide

  • Park, Young-Kyu;Chung, Gwiy-Sang;Seo, Yong-Su
    • Journal of Electrical Engineering and information Science
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    • v.2 no.5
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    • pp.100-107
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    • 1997
  • W have developed the simplified formalism of PSBM in order to save calculation time and to increase the accuracy. Using this new formalism of PBM, we have evaluated the loss of the three kinds of waveguide; bent, Y-branch, and cascaded Y-branches. It takes nearly half of the conventional PBM calculation time, even in spite of increasing of he calculation accuracy. This simplified formalism of PBM would be used efficiently in analysis of complicated three dimensional dielectric optical waveguide.

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Devlopment HLA DEVS-Obj-C Environment for Distributed Simulation (분산 시뮬레이션을 위한 HLA DEVS-Obj-C 환경 구축)

  • 최두진;조대호
    • Proceedings of the Korea Society for Simulation Conference
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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

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A Methodology for Variable Structure System Specification: Formalism, Framework, and Its Application to ATM-Based Network System

  • Lee, Kyou-H.;Choi, Kil-Y.;Kim, Jae-G.;Vansteenkiste, G.C.
    • ETRI Journal
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    • v.18 no.4
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    • pp.245-264
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    • 1997
  • This paper presents a formalism-based methodology and its implemented environment which constitutes a sound framework for real-time systems development. The software and/or hardware systems developed in such a formal manner are well structured and maintainable. We first propose a set-theoretic VSSS (Variable Structure System Specification) formalism. This formalism is the core of the presented methodology which supports a means of formal specification for real-time systems. We then develop the environment, including VSSS language definition, a translator for the language, and supporting libraries for real-time execution. Finally, a demonstration of the methodology in development of a real-time event manager, a subsystem of an ATM-based communication system, shows the correctness and efficiency of the methodology.

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Integrated Hybrid Modeling Methodology and Simulation Engine Design Based on HDEVS Formalism (HDEVS 형식론에 기반한 통합 하이브리드 모델링 방법론 및 시뮬레이션 엔진 설계)

  • Kwon, Se Jung;Sung, Changho;Song, Hae-Sang;Kim, Tag Gon
    • Journal of the Korea Society for Simulation
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    • v.22 no.1
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    • pp.21-30
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    • 2013
  • A hybrid system is a combination of sub systems which have different types of state and time: a typical example is a combination of discrete event and continuous systems. A HDEVS(Hybrid DEVS) formalism was proposed for modeling and analyzing a hybrid system. The HDEVS formalism allows modelers to construct a hierarchical and modular model based on the mathematical set theory. Because the HDEVS formalism was applied to the distributed and interoperated simulators, modelers should make several heterogenous models dividing a target system. Hence, this paper proposes an extended hybrid coupled model of HDEVS formalism and an integrated hybrid modeling methodology in contrast to the existing simulation framework on interoperable simulators. By applying the proposed modeling method, a target system can be translated to a hybrid model in a similar form as the target system. This paper also contains a simulation engine design for the proposed modeling methodlogy and a case study which simulates water tank control systems.

Logical Analysis of Real-time Discrete Event Control Systems Using Communicating DEVS Formalism (C-DEVS형식론을 이용한 실시간 이산사건 제어시스템의 논리 해석 기법)

  • Song, Hae Sang;Kim, Tag Gon
    • Journal of the Korea Society for Simulation
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    • v.21 no.4
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    • pp.35-46
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    • 2012
  • As complexity of real-time systems is being increased ad hoc approaches to analysis of such systems would have limitations in completeness and coverability for states space search. Formal means using a model-based approach would solve such limitations. This paper proposes a model-based formal method for logical analysis, such as safety and liveness, of real-time systems at a discrete event system level. A discrete event model for real-time systems to be analyzed is specified by DEVS(Discrete Event Systems Specification) formalism, which specifies a discrete event system in hierarchical, modular manner. Analysis of such DEVS models is performed by Communicating DEVS (C-DEVS) formalism of a timed global state transition specification and an associated analysis algorithm. The C-DEVS formalism and an associated analysis algorithm guarantees that all possible states for a given system are visited in an analysis phase. A case study of a safety analysis for a rail road crossing system illustrates the effectiveness of the proposed method of the model-based approach.