Showing papers by "Bernard P. Zeigler published in 2001"

A layered modeling and simulation architecture for agent-based system development

Abstract: The paper proposes a layered architectural framework to support agent based system development in a collaborative, multidisciplinary engineering setting. This architecture is viewed from two distinct perspectives. First, the environment must enable agent based modeling and simulation. Second, it should support concurrent (team oriented) engineering. The main focus is on the proposed layered architecture delineating various needs of an agent based system, thus supporting incremental specification design, implementation, and testing. In our discussions, we distinguish between performing agents and simulated agents. The former refers to agents as they are performing their tasks in real-world settings. The latter refers to agents that have their behavior simulated in a virtual environment. In these terms, the proposed framework is intended to form the basis for environments that support development of agents, in both performance and simulation modes, as well as in hybrid combination (both performing and simulated agents interacting at the same time). The proposed framework is a step toward realization of agent based systems under the umbrella of the simulation based acquisition (SBA) initiative of the US Department of Defense.

Discrete event modeling and simulation technologies : a tapestry of systems and AI-based theories and methodologies

Abstract: Introduction.- Part I: Modeling & simulation.- Part II: AI.- Part III: Software engineering.- Part IV: Collaborative/distributed computing.The complete table of contentscan be found on the Internet:http://www.springer.de

Design and implementation of distributed real-time DEVS/CORBA

Abstract: In this paper the design and implementation of Distributed Real-Time DEVS/CORBA is discussed as an extension of previously developed DEVS-based modeling and simulation frameworks. The major objective in developing Distributed Real-Time DEVS/CORBA is to establish a framework in which the distributed real-time systems can be designed through DEVS-based modeling and simulation studies, and then migrated with minimal additional effort to be executed in the real-time distributed environment. This environment will provide generic support for developing models of distributed embedded software systems, evaluating their performance and timing behavior through simulation and easing the transition from simulation to actual executions In this paper we describe detailed design and implementation aspects of the environment which was implemented over Visibroier CORBA middleware and ACE/TAO real-time CORBA services.

DEVS-on-a-chip: implementing DEVS in real-time Java on a tiny Internet interface for scalable factory automation

Abstract: This paper describes our effort to implement DEVS on a TINI Chip which has limited memory and processing ability. A set of well-defined DEVS interfaces make it possible to define a just-as-needed DEVS real time environment and run on the chip efficiently. As a case study for real time data gathering, processing and management, a DEVS coupled model has been composed from a set of primitive DEVS atomic models in this application area. This coupled model gets real time temperature from a sensor and runs data processing such as quantizer, moving averager, maximum and minimum extractor, etc. before it transfers the data to database.

Rtdevs/corba: a distributed object computing environment for simulation-based design of real-time discrete event systems

Abstract: Ever since distributed systems technology became increasingly popular in the real-time computing area about two decades ago, real-time distributed object computing technologies have been attracting more attention from researchers and engineers. While highly effective object-oriented methodologies are now widely adopted to reduce the development complexity and maintenance costs of large scale non-real-time software applications, real-time systems engineering practice has not kept pace with these system development methodologies. Indeed, real-time design techniques have not fully adopted the concepts of modular design and analysis which are the main virtues of object-oriented design technologies. As a consequence, the demand for object-oriented analysis, design, and implementation of large-scale real-time applications has been growing. To address the need for object-oriented real-time systems engineering environments we propose the Real-Time DEVS/CORBA (RTDEVS/CORBA) distributed object computing environment. In this dissertation, we show how this environment is an extension of previously developed DEVS-based modeling and simulation frameworks that have been shown to support an effective modeling and simulation methodology in various application areas. The major objective in developing Distributed Real-Time DEVS/CORBA is to establish a framework in which distributed real-time systems can be designed through DEVS-based modeling and simulation studies, and then migrated with minimal additional effort to be executed in the real-time distributed environment. This environment provides generic support for developing models of distributed embedded software systems, evaluating their performance and timing behavior through simulation

DEVS modeling and simulation: a new layer of middleware

Abstract: This paper discusses a concept of DEVS middleware that would provide a set of services for constructing discrete event models and executing them in simulation or in real-time. Although generic middleware such as CORBA and MPI supports simulation and simulation-oriented middleware such as High Level Architecture Runtime Infrastructure exists, there are many issues that either not addressed at all or have been inadequately addressed in existing systems. DEVS Middleware would improve modeling and simulations due to the beneficial formal properties of DEVS, enhance interoperability among components adhering to the DEVS protocol, and reduce programming complexity by hiding lower level Simulation and execution details. The DEVS Middleware concept includes components for model construction and for mapping models onto simulators or real-time execution engines to support the novel concept of "distributed programming by modeling." This paper discusses several sub-layers that have been identified within the overall DEVS middleware concept, existing work that can be brought to bear on developing these layers and the integration needed to create a widely accepted standard.

Design and Development of Data Distribution Management Environment

Abstract: This paper describes the design and development of the DEVS/GDDM environment, a layered simulation environment that supports data dis tribution management and allows us to study space-based quantization schemes. These schemes aim to achieve effective reduction of data commu nication in distributed simulation. After a brief review of the space-based quantization scheme and an HLA-Interface environment, we discuss the design issues of the DEVS/GDDM environ ment. We analyze system performance and scalability of the space-based quantization scheme, especially with predictive and multiplex ing extensions, and empirical results for a ballis tic missiles simulation executing on the DEVS/ GDDM environment on NT networking plat forms. The results indicate the DEVS/GDDM environment is very effective and scalable due to reduced local computation demands and ex tremely favorable communication data reduction.

Space-based data management for high performance distributed simulation

Abstract: 14 There is a rapidly growing demand to model and simulate complex large-scale distributed systems and to collaboratively share geographically dispersed data assets and computing resources to perform such distributed simulation with reasonable conmiunication and computation resources. Interest management schemes have been studied in the literature. In this dissertation we propose an interest-based quantization scheme that is created by combining a quantization scheme and an interest management scheme. We show that this approach provides a superior solution to reduce message traffic and network data transmission load. As an environmental platform for data distribution management, we extended the DEVS/HLA distributed modeling and simulation environment. This environment allows us to study interest-based quantization schemes in order to achieve effective reduction of data communication in distributed simulation. In this environment, system modeling is provided by the DEVS (Discrete Event System Specification) formalism and supports effective modeling based on hierarchical and modular object-oriented technology. Distributed simulation is performed by a highly reliable facility using the HLA (High Level Architecture). The extended DEVS/HLA environment, called DEVS/GDDM (Generic Data Distribution Management), provides a high level abstraction to specify a set of interest-based quantization schemes. This dissertation presents a performance analysis of centralized and distributed configurations to study the scalability of the interest-based quantization schemes. These 15 results illustrate the advantages of using space-based quantization in reducing both network load and overall simulation execution time. A real world application, relating to ballistic missiles simulation, demonstrates the operation of the DEVS/GDDM environment. Theoretical and empirical results of the ballistic missiles application show that the space-based quantization scheme, especially with predictive and multiplexing extensions, is very effective and scalable due to reduced local computation demands and extremely favorable conmiunication data reduction with a reasonably small potential for error. This realistic case study establishes that the DEVS/GDDM environment can provide scalable distributed simulation for practical, real-world applications.

Capacity analysis for mixed technology production: Evaluating production ramp resource modifications via distributed simulation

Abstract: This paper describes the design and development of a discrete event simulation based, dynamic, capacity analysis tool. Manufacturing capacity analysis, traditionally approached through the prescribed tools of mathematical programming, is presently devoid of a dynamic simulation framework that delivers multi-period asset evaluations based on a real-time performance estimate. A suggested framework for this class of decisions involves periodic (quarterly), deterministic, constrained evaluation models to specify resource allocation decisions. Capacity evaluation models are inherently non-stationary due to the structural modifications that occur when adding new production resources. Homogeneity is employed here in the uniform description of heterogeneous resources as general mathematical objects, or discrete event models (DEVS). Each object represents both the individual production resource's dynamic state and static parameters. Exercising these objects via simulation optimizes resources through Return on Oper...

Interface for scalable DEVS and distributed container object specifications

Abstract: In this paper, we present two specifications, scalable DEVS specification and distributed container object specification, to support scalability and interoperability of DEVS-based modeling and simulation (M and S) systems. The scalable DEVS specification lists a set of interfaces which create and simulate DEVS models, and control simulation activities among simulators. The distributed container object specification provides a heterogeneous and distributed collection framework focusing on ensemble operations. The proposed specifications contain a rich set of both data and operations which are necessary for building scalable M and S environments that should provide invariance in both performance and quality of service of a system as the size, complexity, and interdependence of its elements increases. We describe design and implementation aspects of those specifications.

Development of DEVS/GDDM environment: realization of space-based data management

Abstract: This paper describes the design and development of DEVS/GDDM, an environmental platform for data distribution management, that allows us to study the interestbased quantization scheme in order to achieve effective reduction of data communication in distributed simulation. After a brief review of interest-based quantization scheme, we discuss the implementation of this scheme as a layer above the DEVS/HLA modeling and simulation environment. This paper presents theoretical analysis for bandwidth utilization of the interest-based quantization scheme, especially with predictive and multiplexing extensions, and empirical results in ballistic missiles simulation executing on the DEVS/GDDM environment in NT networking platforms. The results indicate that the DEVS/GDDM environment is very effective and scalable due to reduced local computation demands and extremely favorable communication data reduction with a reasonably small potential for error.