Hierarchical, modular discrete-event modelling in an object-oriented environment

SIMULATION ◽  
1987 ◽  
Vol 49 (5) ◽  
pp. 219-230 ◽  
Author(s):  
Bernard P. Zeigler
Keyword(s):  
Distributed Simulation ◽  
Discrete Event ◽  
Object Oriented ◽  
Simulation Models ◽  
Object Oriented Programming ◽  
Model Base ◽  
Knowl Edge ◽  
Design Alternatives ◽  
Event Models ◽  
Devs Formalism

Hierarchical, modular specification of discrete-event models of fers a basis for reusable model bases and hence for enhanced simulation of truly varied design alternatives. We describe an envi ronment which realizes the DEVS formalism developed in Zeigler (1984) for hierarchical, modular models. It is implemented in PC-Scheme, a powerful Lisp dialect for microcomputers contain ing an object-oriented programming subsystem. Since both the implementation and the underlying language are accessible to the user, the result is a capable medium for combining simula tion modelling and artificial intelligence techniques. The envi ronment is developed in an object-oriented manner which lends itself to model base organization using the entity structure knowl edge representation. It also serves as a medium for developing hierarchical distributed simulation models and architectures.

DEVSim++ Toolset for Defense Modeling and Simulation and Interoperation

2010 ◽  
Vol 8 (3) ◽  
pp. 129-142 ◽  
Author(s):  
Tag Gon Kim ◽  
Chang Ho Sung ◽  
Su-Youn Hong ◽  
Jeong Hee Hong ◽  
Chang Beom Choi ◽  
...  
Keyword(s):  
Modeling And Simulation ◽  
Distributed Simulation ◽  
Discrete Event ◽  
Model Verification ◽  
High Level Architecture ◽  
Event Models ◽  
The Republic ◽  
Devs Formalism ◽  
High Level ◽  
The Military

Discrete Event Systems Specification (DEVS) formalism supports the specification of discrete event models in a hierarchical and modular manner. Efforts have been made to develop the simulation environments for the modeling and simulation (M&S) of systems using DEVS formalism, particularly in defense M&S domains. This paper introduces the DEVSim++ toolset and its applications. The Object-Analysis Index (OAI) matrix is a tabular form of objects and analysis indices for requirements analysis. DEVSim++ is a realization of DEVS formalism in C++ for M&S. VeriTool is a DEVS model verification tool. DEVSimHLA is a library to support High-level Architecture (HLA) in DEVSim++. Other tools, including KComLib, FOM2CPPClass, and KHLAAdaptor, are used to develop a smart adaptor that allows for the interoperation of simulators of any kind. PlugSim is a distributed simulation framework using plug-in methods. These tools are utilized in every stage of the M&S development process, as well as in every application of the M&S missions to the military domain. Accordingly, the applications implemented by the toolset are used in the training, analytic, and acquisition missions of the Republic of Korea military branches. We expect the DEVS applications to become more prolific as M&S demands grow, and our toolset is already proven as complete and efficient in the domain of defense M&S.

The DEVS Formalism

2013 ◽  
pp. 62-102
Author(s):  
Rhys Goldstein ◽  
Gabriel A. Wainer ◽  
Azam Khan
Keyword(s):  
Formal Specification ◽  
Discrete Event ◽  
Simulation Models ◽  
Object Oriented Programming ◽  
Event Simulation ◽  
The Core ◽  
Modular Model ◽  
Core Concepts ◽  
Devs Formalism ◽  
The Relationship

The DEVS formalism is a set of conventions introduced in 1976 for the specification of discrete event simulation models. This chapter explains the core concepts of DEVS by applying the formalism to a single ongoing example. First, the example is introduced as a set of informal requirements from which a formal specification is to be developed. Readers are then presented with alternative sets of modeling conventions which, lacking the DEVS formalism’s approach to representing state, prove inadequate for the example. The chapter exploits the DEVS formalism’s support for modular model design, as the system in the example is specified first in parts and later as a combination of those parts. The concept of legitimacy is demonstrated on various model specifications, and the relationship between DEVS and both object-oriented programming and parallel computing is discussed.

Using Object-Oriented Frame Language for Realizing Discrete Event Simulation

1996 ◽  
Author(s):  
Ming Dong ◽  
Jianzhong Cha ◽  
Mingcheng E
Keyword(s):  
Knowledge Base ◽  
Discrete Event Simulation ◽  
Discrete Event ◽  
Object Oriented ◽  
Simulation Models ◽  
Activity Cycle ◽  
Event Simulation ◽  
Knowledge Based ◽  
Inference Engines ◽  
Reasoning About Knowledge

Abstract In this paper, we realize knowledge-based discrete event simulation model’s representation, reasoning and implementation by means of object-oriented(OO) frame language. Firstly, a classes library of simulation models is built by using the OO frame language. And then, behaviours of simulation models can be generated by inference engines reasoning about knowledge base. Lastly, activity cycle diagrams can be used to construct simulation network logic models by connecting the components classes of simulation models. This kind of knowledge-based simulation models can effectively solve the modeling problems of complex and ill-structure systems.

scholarly journals WSN-SES/MB: System Entity Structure and Model Base Framework for Large-Scale Wireless Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 430
Author(s):  
Su Man Nam ◽  
Hyung-Jong Kim
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Large Scale ◽  
Discrete Event ◽  
Cost Savings ◽  
Simulation Models ◽  
Wireless Sensor ◽  
System Specification ◽  
Model Base ◽  
System Entity Structure

Large-scale wireless sensor networks are characterized by stringent energy and computation restrictions. It is exceedingly difficult to change a sensor network’s environment configurations, such as the number of sensor nodes, after deployment of the nodes. Although several simulators are able to variously construct simulation models for sensor networks before their deployment, the configurations should be modified with extra human effort as the simulators cannot freely generate diverse models. In this paper, we propose a novel framework, called a system entity structure and model base for large-scale wireless sensor networks (WSN-SES/MB), which is based on discrete event system specification formalism. Our proposed framework synthesizes the structure and models for sensor networks through our modeling construction process. The proposed framework achieves time and cost savings in constructing discrete event simulation-based models. In addition, the framework increases the diversity of simulation models by the process’s pruning algorithm. The simulation results validate that the proposed framework provides up to 8% time savings and up to 23% cost savings as compared to the manual extra effort.

A Synchronization Mechanism with Shared Storage Model for Distributed Manufacturing Simulation Systems

2015 ◽  
Vol 9 (3) ◽  
pp. 248-260 ◽  
Author(s):  
Hironori Hibino ◽  
◽  
Yoshiro Fukuda ◽  
Yoshiyuki Yura ◽  
◽  
...  
Keyword(s):  
Manufacturing Systems ◽  
Manufacturing System ◽  
Distributed Simulation ◽  
Discrete Event ◽  
Simulation Models ◽  
Model Concept ◽  
Shared Storage ◽  
Storage Model ◽  
Synchronization Mechanism ◽  
Simulation Systems

Simulators play important roles in the designing of new acturing systems. As manufacturing systems are being created on larger and more complicated scales than ever before, it is increasingly necessary to have opportunities for several persons to design a manufacturing system concurrently. In this case, the designers often use suitable discrete event simulators to evaluate their assigned subsystems. After the subsystems are evaluated, it is necessary to evaluate the full system. To do this, the designers need to make the manufacturing system model by synchronizing several different simulators. In such distributed simulation systems using discrete event simulators, it is important to manage a distributed simulation clock and each simulator clock as well as to define interfaces among the simulation models. With the simulation clock, it is often necessary to perform rollbacks. The rollback function returns the simulation clock to a past time in order to synchronize events among the simulations. However, most commercially available simulators do not include the rollback function.The purpose of this research is to develop a distributed simulation synchronization method that includes a function for managing distributed simulation clocks without the rollback function and for managing interfaces among simulation models.In this paper, we propose a storage model concept as the method. We develop an algorithm to implement the proposed concept, and we develop a distributed simulation system configuration using HLA. A case study is then carried out to evaluate the performance of the cooperative work.

COMBINING MODELICA MODELS WITH DISCRETE EVENT FORMALISMS FOR SIMULATION USING THE DES/M ENVIRONMENT

2005 ◽  
Vol 15 (02) ◽  
pp. 349-355 ◽  
Author(s):  
MANUEL A. PEREIRA REMELHE ◽  
SEBASTIAN ENGELL
Keyword(s):  
Modeling And Simulation ◽  
Discrete Event ◽  
Object Oriented ◽  
Software Tools ◽  
Modeling Languages ◽  
Physical Systems ◽  
Simulation Techniques ◽  
Discrete Event Control ◽  
Event Models ◽  
Technical Systems

Technical systems that include complex physical dynamics as well as extensive discrete event control, require powerful modeling and simulation techniques. As the most adequate means for modeling hybrid physical systems, we advocate the use of object-oriented modeling languages such as Modelica. However, the discrete event models often require the use of dedicated graphical editors that cannot be defined appropriately using Modelica. The purpose of the DES/M modeling environment [10] is to provide such editors for different discrete event formalisms and to translate discrete event models automatically into Modelica components such that a discrete event controller can be integrated easily into Modelica models and simulated using standard Modelica software tools. This contribution presents the main concepts used for the representation of several discrete event formalisms in the Modelica language and discusses the class of discrete event formalisms that can be supported by the DES/M environment.

Discrete Event Simulation: An Efficient Tool to Assist Shipyard Investment and Production Planning

2004 ◽  
Vol 20 (03) ◽  
pp. 176-182
Author(s):  
Matthias Krause ◽  
Frank Roland ◽  
Dirk Steinhauer ◽  
Maximilian Heinemann
Keyword(s):  
Discrete Event Simulation ◽  
Discrete Event ◽  
Object Oriented ◽  
Simulation Models ◽  
Resource Planning ◽  
Simulation Tool ◽  
Production Flow ◽  
Holistic Model ◽  
Event Simulation ◽  
Tool Set

The complexity both of the product ship and the shipbuilding process make planning tasks in long, medium, and short terms difficult and lead to serious uncertainties. Discrete event simulation can be used to test and evaluate different scenarios in investment planning, scheduling, and resource planning. Using a virtual shipyard environment, the cost to find optimum solutions and the risk related to wrong decisions in the real world can be drastically reduced. However, due to the special skills and efforts usually needed to develop simulation models, the practical application of production flow simulation in shipyards is still rather limited. Object-oriented simulation tool sets specially developed for shipbuilding needs provide the chance to drastically reduce these efforts. Object libraries containing general and shipbuilding specific components with defined interfaces shorten the time needed for development of models for similar purposes. Furthermore, the integration of discrete event simulation models for certain shipyard facilities into a holistic model of the entire enterprise is made possible by using a tool set. Because of costs, some shipyards shy away from investing in simulation techniques. Networking activities and joint projects on simulation issues help to overcome those obstacles. German Flensburger Schiffbaugesellschaft already uses a simulation tool set successfully and actively cooperates with universities and other shipyards, while Center of Maritime Technologies has gathered experience in this field during participation in several simulation projects with other shipyards, for example, Jos. L. Meyer and Aker Ostsee. The article revues practical applications of simulation, gives an impression of how object-oriented simulation tool libraries can be structured, and outlines collaboration possibilities for making simulation applications affordable.

scholarly journals DVCompute Simulator for discrete event simulation

2021 ◽  
Vol 16 (93) ◽  
pp. 93-108
Author(s):  
David E. Sorokin ◽  
Keyword(s):  
Discrete Event Simulation ◽  
Large Scale ◽  
Distributed Simulation ◽  
Discrete Event ◽  
Simulation Models ◽  
General Purpose ◽  
Agent Based Modeling ◽  
Agent Based ◽  
Event Simulation ◽  
Programming Techniques

The author of this article represents his own work DVCompute Simulator, which is a collection of general-purpose programming libraries for discrete event simulation. The aim of the research was to create a set of simulators in the Rust language, efficient in terms of speed of execution, based on a unified approach and destined for different simulation modes. The simulators implement such modes as ordinary sequential simulation, nested simulation and distributed simulation. The article describes that nested simulation is related to Theory of Games, while distributed simulation can be used for running large-scale simulation models on supercomputers. It is shown how these different simulation modes can be implemented based on the single approach that combines many paradigms: the event-oriented paradigm, the process-oriented one, blocks similar to the GPSS language and even partially agent-based modeling. The author's approach is based on using the functional programming techniques, where the simulation model is defined as a composition of computations. The results of testing two modules are provided, where the modules support both the optimistic and conservative methods of distributed simulation.

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