Table of Contents:

  1. Principal Investigator.
  2. Productivity Measures.
  3. Summary of Objectives and Approach.
  4. Detailed Summary of Technical Progress.
  5. Transitions and DOD Interactions.
  6. Software and Hardware Prototypes.
  7. List of Publications.
  8. Invited and Contributed Presentations.
  9. Honors, Prizes or Awards Received.
  10. Project personnel promotions obtained.
  11. Project Staff.
  12. Misc Hypermedia URL.
  13. Keywords.

Principal Investigator.

Productivity Measures.

Summary of Objectives and Approach.

  1. Virtual reality (VR) is emerging as an important approach to the modeling and simulation of complex systems. But software technology for scientists to build VR-based applications fosters development of closed applications each built from scratch. A scientist's ability to merge models and systems once developed is solely dependent upon their ability to `hack' software, since the principles of VR system interconnection are poorly understood and no software engineering guidelines have ever been developed for use in VR applications. We are studying the issue of interoperation between VR systems, that is the virtual environment, in order to discover essential principles governing their construction and effective use. Our approach focuses upon the control properties of interfaces between VR applications: existing VR applications will be examined in order to expose commonalities, and our abstractions of VR control behavior will be specified in terms of the software bus model of interconnection. As principles of VR interoperation emerge, we will build prototype implementations of corresponding software interconnection tools to evaluate the application of those principles back in the domains from which our test problems were drawn. As a result of this research, scientists who use VR technology will have a sound basis for leveraging existing resources in new applications, and similarly, they will have an appropriately abstract framework for specifying how multiple models should be merged operationally.

Detailed Summary of Technical Progress.

  1. Our analysis of existing VR applications proceeds as study architectural walk-through programs. In collaboration with colleagues at University of North Carolina at Chapel Hill, we have preliminary apparatus assembled to interconnect multiple instantiations of existing walk-through processes, and will shortly be testing this mapped across various underlying network configurations.

Transitions and DOD Interactions.

Software and Hardware Prototypes.

List of Publications.

  1. Surgeon: a packager for dynamically reconfigurable distributed applications. C. Hofmeister, E. White and J. Purtilo. Software Engineering Journal, vol. 8, no. 2, (March 1993), pp. 95-101.
  2. The Polylith Software Bus. J. Purtilo. ACM Transactions on Programming Languages and Systems}, vol. 16, no. 1, (January 1994), pp. 151-174.
  3. A pattern-based object linking mechanism for component-based software development environments. L. Spicknall Fruth, E. White and J. Purtilo To appear, Journal of Systems and Software.
  4. Dynamic reconfiguration in distributed systems: Adapting software modules for replacement. C. Hofmeister and J. Purtilo. IEEE International Conference on Distributed Computer Systems, pp. 101-110, (May 1993).
  5. A packager for multicast software in distributed systems. C. Chen, E. White and J. Purtilo. International Conference on Software Engineering and Knowledge Engineering}, (1993), pp. 612-621.
  6. Experiences with CCB-directed projects in the classroom. J. Purtilo and S. Siegel. Proceedings of SEI Conference on SE Education, (1994), pp. 285-302.
  7. Planning for change: a reconfiguration language for distributed systems. B. Agnew, C. Hofmeister and J. Purtilo. Proceedings of International Workshop on Configurable Distributed System, (1994), pp. 15-22.
  8. Virtual environment architectures: interoperability through software interconnection technology. P.D. Stotts and J. Purtilo. Proceedings of Third IEEE Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises, Morgantown WVa, IEEE Computer Society Press, (April 1994), pp. 211-224.
  9. Tool support for tailored software prototyping. C. Chen, A. Porter and J. Purtilo. Proceedings of Symposium on Assessment of Quality Software Development Tools, (June 1994), pp. 171-181.
  10. Configuration-level programming of distributed applications using implicit invocation. C. Chen and J. Purtilo. Proceedings of IEEE Int'l Conference on Frontiers of Computer Technology, Singapore, (August 1994), pp. 43-49.

Invited and Contributed Presentations.

Honors, Prizes or Awards Received.

Project Personnel Promotions Obtained.

Project Staff.

  1. The entire interconnection team is
  2. Jim Purtilo

  3. Liz White

  4. Chen Chen

  5. Tae-Hyung Kim

  6. Charles Falkenberg

  7. Gilberto Matos

  8. Liqin Cao

  9. Scott Walker

  10. Brent Agnew

  11. Jim Duff

  12. ... And the Next Generation ...

Misc Hypermedia.


  1. Dynamic reconfiguration
  2. Software bus
  3. Virtual Reality Infrastructure