WSC 2004 Final Abstracts

Tuesday 1:30:00 PM 3:00:00 PM
Web-enabled Government/Defense Applications
Chair: Ernie Page (Mitre)

Efficient Process Interaction Simulation in Java: Implementing Co-Routines Within a Single Java Thread
Richard M. Weatherly and Ernest H. Page (The MITRE Corporation)

Abstract:
The genesis of a research effort to develop a Java-based process-oriented simulation framework is described. A key enabler to the framework is an efficient co-routine mechanism implemented within the context of a single Java thread. A design for such a co-routine mechanism is described and some initial results of an implementation within the IBM Jikes Reference Virtual Machine are given.

Implementing the High Level Architecture in the Virtual Test Bed
José A. Sepúlveda, Luis Rabelo, and Jaebok Park (University of Central Florida), Frank Riddick (National Institute of Standards and Technology) and Cary Peaden (NASA)

Abstract:
The Virtual Test Bed (VTB) is a prototype of a virtual engineering environment to study operations of current and future space vehicles, spaceports, and ranges. The High-Level Architecture (HLA) as defined by the Department of Defense (DoD), is the main environment. The VTB/HLA implementation described here represents different systems that interact in the simulation of a Space Shuttle liftoff. This example implementation displays the collaboration of a simplified version of the Space Shuttle Simulation Model and a simulation of the Launch Scrub Evaluation Model. Spaceports and ranges are complex systems. This VTB framework is a collaborative computing environment that integrates in a seamless fashion simulation models that represent the different stages in the lifecycle of a complex system. A complex system is a non-linear system of systems whose interactions bring together interesting emergent properties that are very difficult to visualize and/or study by using the traditional approach of decomposition.

Parallel Discrete Event Simulation of Space Shuttle Operations
Luis Rabelo, José Sepúlveda, Mario Marin, Amith Paruchuri, Amit Wasadikar, and Karthik Nayaranan (University of Central Florida)

Abstract:
This paper describes the application of parallel simulation techniques to represent structured functional parallelism present within the Space Shuttle Operations Flow, utilizing the Synchronous Parallel Environment for Emulation and Discrete-Event Simulation (SPEEDES), an object-oriented multicomputing architecture. SPEEDES is a unified paral-lel simulation environment, which allocates events over multiple processors to get simulation speed up. Its optimis-tic processing capability minimizes simulation lag time behind wall clock time, or multiples of real-time. SPEEDES accommodates increases in processes complex-ity with additional parallel computing nodes to allow shar-ing of processing loads. This papers focuses on the whole process of developing a model of Space Shuttle Operations Flow represented in a process-driven approach, from the physical systems and processes being simulated, through object oriented design, verification, validation, and imple-mentation.

Abstract:
This paper provides an introduction to the Simulation Reference Markup Language (SRML) through a case study in which a simple self-describing process modeling and simulation representation is developed.

Using XML and BOMs to Rapidly Compose Simulations and Simulation Environments
Paul Gustavson (SimVentions, Inc.) and Tram Chase (SimVentions, Inc)

Abstract:
This paper explores the application of Base Object Models (BOMs), an emerging XML standard, for rapidly composing simulations and simulation environments. We examine how pattern components, supported by the Interface (IF) BOM, play an effective role in defining compositions, and how behavior components, supported by the Encapsulated (ECAP) BOM, can be used to enable simulations both at design time and dynamically at run-time. Finally we explore the potential opportunities BOMs and other XML standards provide for the future of web-based simulation and training.

XML Mediation Services Utilizing Model Based Data Management
Andreas Tolk (Old Dominion University)

Abstract:
The application of XML enabled a new level of interoperability for heterogeneous IT systems. However, XML doesn't ensure that data exchanged is interpreted correctly. This motivates data management to support unambiguous definition of data elements for information exchange. Using a common reference model improves this process leading to "model based data management." The results can be used to configure mediation layers integrating services into a service-oriented architecture. The results of MBDM can be applied in form of an auto-generated XSLT definition used to compose the service without additional modifications with other services. The paper uses the Command and Control Information Exchange Data Model (C2IEDM) – as an example for a common reference model for information exchange – and its potential use in the Global Information Grid – as the military example for a service oriented architecture – to integrate web-enabled M&S applications as an example for applying this method.

SRML Case Study: Simple Self-Describing Process Modeling and Simulation
Steven W. Reichenthal (Boeing)

Abstract:
We describe a different approach to using XML to support the simulation modeling of supply chains. Instead of using XML to specify the simulation constructs, as most previous approaches do, we utilize XML to describe the supply chain itself. The Supply Chain Modeling Language (SCML) is a general, reusable, platform and methodology independent standard for describing a supply chain’s structure and logic. SCML is usable by analysts using many methodologies, including simulation. We describe a sample simulation system (SISCO) that uses SCML files as input. This system uses an algorithm to “map” the SCML file contents to simulation classes contained in a supply chain simulation class library, resulting in an object-oriented simulation model of the supply chain.

Examining the Feasibility of Constructing Simulation Models Using the Web-Based 'Grab-and-Glue' Framework
Tillal Eldabi, Man Wai Lee, and Ray J. Paul (Brunel University)

Abstract:
The Grab and Glue discrete event simulation (Grab-and-Glue) framework has been proposed for several years. This paper investigates the feasibility of this framework. A simulation model of a single server queuing system is constructed by following the Grab-and-Glue framework as a ubiquitous example. Different scissions are grabbed from the Web or programming textbooks, and glued together using JBuilder5. The potential of Grab-and-Glue is discussed as well as the current challenges of constructing Grab-and-Glue simulation models. Some critiques and recommendations for the ongoing research on constructing simulation models based on the Grab-and-Glue framework have also been proposed.

HDPS, an XML/XSLT Based Hierarchal Modeling System
Richard Evan Curry (London Business School) and Kiriakos Vlahos (Athens Laboratory of Business Administration)

Abstract:
HDPS is a practical system for designing modeling paradigms, creating hierarchal model definitions, and evaluating multi-paradigm models - particularly in business and finance. HDPS relies on XML (W3C 2004) to create model types, definitions, and instances. A type defines a modeling paradigm; for example, one type might define discrete event simulation while another may specify linear programming. A definition describes a system such as a firm’s pricing decision process. A model instance is the state and history of a definition when operated upon by a type. Further, each type relies on one or more implementations to provide its functionality. xHDPS, a .NET version of HPDS, implements several modeling paradigms including simulation (discrete event, continuous time, and Monte-Carlo), optimization (linear and non-linear), knowledge-based expert systems, and general calculation (spreadsheet) models. A multi-generation service adoption model demonstrates a typical HDPS model structure with several interconnected models utilizing different modeling paradigms.

XML-Based Supply Chain Simulation Modeling
Dean C. Chatfield (Virginia Tech) and Terry P. Harrison and Jack C. Hayya (Penn State)