Distributed Simulation Systems for Multi-Agent Models and Distributed Virtual Environments



Complex autonomous systems involve dynamic and unpredictable interactions between large numbers of components including software, hardware devices (such as sensors), and social entities (people or collective bodies). Examples of such systems range from embedded systems such as robots and autonomous vehicles, to systems controlling critical infrastructures, such as defence and smart city systems, to biological systems, to business applications with decision-making capabilities, to social systems and services, such as e-government and e-learning, to Digital Twins and Distributed Virtual Environments such as massively multiplayer online games (MMOGs) and Metaverses (e.g. Facebook Meta).

In this landscape, Multi-Agent Systems (MAS) and individual-based modelling play an increasingly critical role at different levels: for modelling and simulating social aspects, actors and stakeholders, as a modelling paradigm for system dynamics and emerging behaviour, and as a key technology for intelligent infrastructure management. MAS have emerged as a particularly suitable paradigm for modelling complex systems. When embedded in a real (e.g. in autonomous vehicles) or virtual system (e.g. a metaverse), a MAS is itself a complex system whose properties and emergent behaviour have also to be analysed via simulation. 

The application of agent-based simulation to ever more complex socio-technical systems-of-systems has placed it in the highly computation-intensive world with computational requirements far exceeding the memory and performance capabilities of conventional computer systems. Distributed simulation has emerged as the  only  viable approach to alleviate the simulation bottleneck in the design and analysis of large, complex, agent-based systems and meet the performance and interoperability requirements of MAS models.  At the same time the emergence of high bandwidth and low latency network and IoT infrastructures have fostered the development of large scale DVE applications which aim to support hundreds of thousands, if not millions, of participants. As DVEs become larger, more data-intensive and latency-sensitive, scalability becomes a crucial element for their successful deployment. With my team we have pioneered the field of Distributed Simulation of complex MAS models and have delivered a set of novel systems for MAS simulation and Distributed Virtual Environments:

  • Developed the PDES-MAS system, a generic optimistic distributed simulation engine specific for MAS and one of the earliest efforts that pioneered the field of distributed simulation of MAS models. PDES-MAS has been the first system to address the problems of state partition, interest management and synchronisation in an integrated, adaptive and fully transparent manner. It is also the first system that has developed optimistic synchronisation for MAS simulations. The development of PDES-MAS started with funding from EPSRC (Project: GR/R45338/01)

  • Investigated the utilisation of the High Level Architecture (HLA) for distributed MAS simulations and developed two different HLA-based Distributed Simulation systems for MAS: HLA_RePast and HLA_Agent. These have been the very first efforts to distribute MAS simulation executives with the HLA, thus pioneering this approach.

  • HLA_RePast is the first ever system to integrate HLA with RePast, a widely used free and open-source, cross-platform, agent-based modeling and simulation toolkit. HLA_RePast allows the development of federations of multiple Java-based lightweight sequential MAS models. 
  • HLA_Agent has integrated HLA with the pioneering SimAgent toolkit which is primarily designed to support the design and implementation of very complex,biologically inspired, cognitively rich agents.

  • In one of the earliest efforts that pioneered the deployment of HLA simulations on the Grid, developed the HLA_Grid_RePast  system for the execution of HLA_RePast  on Grid platforms. This work was part of the DS-Grid project, one of only four international “sister” projects funded by the e-Science Core Programme with the aim to establish synergistic links between individual UK e-Science projects and leading Grid/e-Science projects from around the globe (Project GR/S82862/01, in partnership with NTU, Singapore). This was the first time ever such a cross-continental HLA infrastructure for MAS simulations was set up  and the first time a RePast simulation was partitioned across 2 continents, executing HLA_RePast Federates across UK and Singapore.

  • Developed a series of novel approaches for interest management in distributed simulations and DVEs including: synchronised range queries, adaptive push-pull algorithms, and algorithms for parallel and continuous interest matching.

Systems

Awards

  • 19th Annual ACM Best of Computing, 2014

           

           


    • Outstanding Paper Award, Euro-SIW 2003
    • Outstanding Paper Award, Euro-SIW 2005
  

Events

Publications

Surveys

  • Sameera Abar, Gregory O'hare, Theodoropoulos Georgios, Pierre Lemarinier “Agent based Modeling and Simulation Tools: A Review of the State-of-Art Software”, Computer Science Review (CSR), Elsevier, doi: 10.1016/j.cosrev.2017.03.001
  • Elvis Liu, Theodoropoulos Georgios, "Interest Management for Distributed Virtual Envi-ronments: A Survey", ACM Computing Surveys, Volume 46 Issue 4, April 2014. doi: 10.1145/2535417
  • G. Theodoropoulos, R. Minson, R. Ewald, M. Lees. “Simulation Engines for Multi-Agent Systems” in “Multi-Agent Systems: Simulation and Applications”, edited by Adelinde M. Uhrmacher and Danny Weyns (Editors), Publisher: Taylor and Francis. eBook ISBN 9781315218786,  Chapter 3, 30 pages.

Papers on PDES-MAS

  • Shuyi Chen, Masatoshi Hanai, Zhengchang Hua, Nikos Tziritas, and Theodoropoulos Georgios, “Efficient Direct Agent Interaction in Optimistic Distributed Multi-Agent-System Simulations”, 2020 ACM SIGSIM Conference on Principles of Advanced Discrete Simulation (PADS2020), June 15-17, 2020, Miami, Florida, USA. doi: 10.1145/3384441.3395977
  • Vinoth Suryanarayanan, Georgios Theodoropoulos, “Synchronised Range Queries in Distributed Simulations of Multi-Agent Systems”, ACM Transactions on Modeling and Computer Simulation (TOMACS), Volume 23, Issue 4, October 2013 DOI Bookmark: 10.1145/2517449
  • Vinoth Suryanarayanan, Georgios Theodoropoulos, Michael Lees, “PDES-MAS: Distributed Simulation of Multi-agent Systems”, International Conference on Computational Science, ICCS 2013 Barcelona, Spain, June 5 - June 7, 2013. DOI bookmark. 10.1016/j.procs.2013.05.231
  • M. Lees, B. Logan, G. Theodoropoulos, “Analysing Probabilistically Constrained Optimism”, Concurrency and Computation: Practice and Experience Journal, special issue on “Distributed Simulation, Virtual Environments and Real Time Applications”, Vol 21, 11, 1467-1482, ISSN: 1532-0626, DOI Bookmark: 10.1002/cpe.1397.
  • D. Chen, R. Ewald, G. Theodoropoulos, R. Minson, T Oguara, M. Lees, B. Logan, and A. Uhrmacher “Data Access in Distributed Simulation of Complex Systems”, Journal of Systems and Software, Elsevier, Volume 81, Issue 12, December 2008, Pages 2345-2360. DOI Bookmark:10.1016/j.jss.2008.04.041
  • M. Lees, B. Logan, G. Theodoropoulos, “Using Access Patterns to Analyze the Performance of Optimistic Synchronization Algorithms in Simulations of MAS”, Transactions of the Society for Computer Simulation International, Volume 84, Number 10/11, October 2008, Pages: 481-492. ISSN: 0037-549. DOI Bookmark: 10.1177/0037549708096691.
  • B. G. W. Craenen, V. Suryanarayanan, and G. K. Theodoropoulos. "A middleware for interfacing with simulation systems of multi-agent models". 2nd Workshop on DIstributed SImulation & Online gaming (DISIO 2011), Best Paper Award, In Proceedings of the 4th International ICST Conference on Simulation Tools and Techniques (SIMUTools '11). Barcelona, Spain - March 21, 2011. ICST (Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering), Brussels, BEL, pages 273–279. ISBN 978-1-936968-00-8.
  • Vinoth Suryanarayanan, Bart Craenen, Georgios Theodoropoulos, “Synchronised Range Queries in Distributed Simulations of Multi-Agent Systems”, the 14th International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2010), October 17-20, 2010, Fairfax, Virginia USA. Nominated for Best Paper Award. DOI bookmark: 10.1109/DS-RT.2010.18
  • Vinoth Suryanarayanan, Rob Minson, Georgios Theodoropoulos “Synchronised Range Queries”, 13th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2009) October 2009, Singapore. Nominated for Best Paper Award. DOI Bookmark: 10.1109/DS-RT.2009.31
  • R. Ewald, D. Chen, G. Theodoropoulos, M. Lees, B. Logan, T Oguara and A. Uhr-macher “Performance Analysis on Shared Data Accessing Algorithms for Distributed Simulation of Multi Agent Systems”, the 20th ACM/IEEE/SCS Workshop on Principles of Advanced and Distributed Simulation (PADS 2006), May 23–26, 2006, Raffles Ho-tel, Singapore. Pages: 29-36, ISBN~ISSN:1087-4097, 0-7695-2587-3. doi: 10.1109/PADS.2006.29
  • M. Lees, B. Logan, D. Chen, T. Oguara G. Theodoropoulos “Analysing the Performance of Optimistic Synchronisation Algorithms in Simulations of Multi-Agent Systems”, the 20th ACM/IEEE/SCS Workshop on Principles of Advanced and Distributed Simulation (PADS 2006), May 23–26, 2006, Raffles Hotel, Singapore. Pages: 37 - 44, ISBN ~ ISSN:1087-4097, 0-7695-2587-3. DOI Bookmark: 10.1109/PADS.2006.10 Nominated for Best Paper Award
  • M. Lees, B. Logan, D. Chen, T. Oguara G. Theodoropoulos “Decision-Theoretic Throttling for Optimistic Simulations of Multi-Agent Systems”, The 9th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2005), October 10-12, 2005 Montreal, Qc. Canada. ISBN: 0-7695-2462-1, Pages: 171-178, DOI Bookmark: 10.1109/DISTRA.2005.16
  • T. Oguara, D. Chen, G. Theodoropoulos, M. Lees, B. Logan, “An Adaptive Load Management Mechanism for Distributed Simulation of Multi-agent Systems”, The 9th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2005), October 10-12, 2005 Montreal, Qc. Canada. ISBN: 0-7695-2462-1, Pages: 179-186. DOI Bookmark: 10.1109/DISTRA.2005.9
  • M.Lees, B.Logan, R.Minson, T. Oguara, G. Theodoropoulos “Modelling Environments for Distributed Simulation”, 1st International Workshop on Environments for Multiagent Systems (E4MAS), in conjunction with the 3rd International Joint Conference on Autonomous Agents and Multi-Agent Systems (AAMAS04), New York, 19-23 July 2004. Lecture Notes on Artificial Intelligence (LNAI), No: 3374, 2005. Springer, ISBN 3-540-24575-8, Pages: 150-167. DOI Bookmark: 10.1007/b106134
  • Lees, M., Logan, B., Theodoropoulos, G., “Time Windows in Multi-Agent Distributed Simulation”, Modelling and Simulation of Distributed Systems and Networks, 5th European Simulation Congress (EUROSIM’04), European Simulation Societies Federation), 6-10 September 2004, ESIEE, Cite Descartes, Marne la Vallee, France. ISBN 3-901608-28, Full Papers CD Volume. 6 Pages.
  • M.Lees, B. Logan, R.Minson, T. Oguara, G. Theodoropoulos, “Distributed Simulation of MAS”, Joint Workshop on Multi-Agent and Multi-Agent-Based Simulation (MAMABS’04), in conjunction with the 3rd International Joint Conference on Autonomous Agents and Multi-Agent Systems (AAMAS04), New York, 19-23 July 2004. Lecture Notes on Artificial Intelligence (LNAI), No: 3415, 2005. Springer, ISBN 3-540-25262-2, Pages: 25-36. DOI Bookmark: 10.1007/b106991
  • Lees, M., Logan, B., Theodoropoulos, G., “Adaptive Optimistic Synchronisation in Distributed Simulations of Agent-based Systems”, The 17th European Simulation Multiconference, June 9 - 11, 2003 Nottingham, UK. ISBN 3-936150-25-7 , Pages 77-82.
  • Theodoropoulos, G., Logan, B., “An Approach for Interest Management And Dynamic Load Balancing In Distributed Simulations”, 2001 European Simulation Interoperability Workshop, 2001 Euro-SIW, University of Westminster, Harrow Campus, Harrow, Middlesex, United Kingdom, June 25-27, 2001. Paper No: 01E-SIW-83, Pages 565-571.
  • Logan, B., Theodoropoulos, G. “The Distributed Simulation of Agent-Based Systems”, Proceedings of the IEEE Journal, Special Issue on Agent-Oriented Software Approaches in Distributed Modelling and Simulation. February 2001, Volume 89, Issue 2, Pages: 174-186. DOI Bookmark: 10.1109/5.910853.
  • Theodoropoulos, G., Logan, B., “A Unified Framework for Interest Management and Dynamic Load Balancing in Distributed Simulation” Proceedings of 12th European Simulation Symposium (ESS’2000), 28-30 September 2000, University of Hamburg, Hamburg, Germany, Society for Computer Simulation International, editor: Dietmar Moeller. ISBN 1-56555-190-7, Pages: 111-115.
  • Logan, B., Theodoropoulos, G., “Dynamic Interest Management in the Distributed Simulation of Agent-Based Systems”, Proceedings of 10th AI, Simulation and Planning In High Autonomy Systems Conference, Sheraton Hotel, Tucson, Arizona, March 6-8 2000, Society for Computer Simulation International, editors: H. Sarjoughian, F. Cellier, Michael Marefat, J. Rozenblit, ISBN-10: 1-56555-194-X, ISBN-13: 978-1-56555-194-7, Pages: 45-50.
  • Theodoropoulos, G., Logan, B., “A Framework for the Distributed Simulation of Agent-Based Systems”, 13th European Simulation Multiconference (ESM99), Warsaw, Poland, June 1-4, 1999, editor: H. Szczerbicka. Society for Computer Simulation International, ISBN 1-56555-171-0 Pages: 58-65.
  • Theodoropoulos, G., Logan, B., "Distributed Simulation of Agent-based Systems", Pro-ceedings of 3rd Euro-conference on Parallel and Distributed Computing for Computa-tional Mechanics", Weimar, 20-25 March 1999., editor: B.H.V.Topping, CIVIL-COMP-PRESS, 10 Saxe-Coburg Place, Edinburgh, EH3 5BR, UK, ISBN: 0-948749-59-8. Pag-es: 147-153, doi: 10.4203/ccp.57.7.1

Papers on HLA_RePast

  • Yuanxi Liang, Wentong Cai, Stephen J. Turner, Georgios K. Theodoropoulos, Rob Minson, “Interfacing RePast with HLA Using a Generic Architecture for COTS Simulation Package Interoperability”, 2009 Joint SISO/SCS Spring Simulation Interoperability Workshop (Paper No: 09S-SIW-070) 23-27 March 2009, Doubletree Hotel San Diego-Mission Valley, CA.
  • Minson, R., Theodoropoulos, G., “Distributing RePast Agent-Based Simulations with HLA”, Computation and Concurrency Practice and Experience Journal – Wiley, Volume 20, Issue 10 (July 2008), Pages 1225-1256, ISSN:1532-0626. DOI Bookmark: 10.1002/cpe.1280
  • Minson, R., Theodoropoulos, G., “Distributing RePast Agent-Based Simulations with HLA”, 2004 European Simulation Interoperability Workshop, 2004 Euro-SIW, Edinburgh, June 2004. Paper No: 04E-SIW-046, 12 pages.

Papers on HLA_Grid_RePast

  • Dan Chen, Stephen J. Turner, Wentong Cai, Theodoropoulos Georgios, Muzhou Xiong, Michael Lees, “Synchronization in Simulation Federation Community Networks”, the Journal of Parallel and Distributed Computing, Elsevier. Vol. 70, Issue 2, pp 144-159, February 2010. doi: 10.1016/j.jpdc.2009.10.006
  • Jiang, M., Theodoropoulos, G., Anane, R., “An Architecture for GRID-enabled Distributed Simulation”, International Journal of High Performance Computing and Network-ing (IJHPCN), Special Issue on Performance Evaluation of Web and Grid Based Com-puting. Interscience. Volume 6, Issue 1, June 2009, Pages:47-55. ISSN:1740-0562. doi: 10.1504/IJHPCN.2009.026291
  • D. Chen, G. Theodoropoulos, S. Turner, W. Cai, Y. Zhang, R. Minson, “Large Scale Agent-based Simulation on the Grid”, Future Generation Computer Systems - The International Journal of Grid Computing: Theory, Methods and Applications, ISSN: 0167-739X, Elsevier. Volume 24, Issue 7, July 2008, Pages 658-671. DOI Bookmark: 10.1016/j.future.2008.01.004.
  • G. Theodoropoulos, Y. Zhang, D. Chen, R. Minson, S. Turner, W. Cai X. Yong and B. Logan “Large Scale Distributed Simulation on the Grid”, International Workshop on Large Scale Distributed Simulations on the Grid, (DS-Grid 2006), 6th IEEE International Symposium on Cluster Computing and the Grid 16-19 May 2006, Singapore , Volume 2, Pages 63-71, ISBN: 0-7695-2585-7. DOI Bookmark: 10.1109/CCGRID.2006.151
  • Y. Zhang, G. Theodoropoulos, R. Minson, S. Turner, W. Cai X. Yong and B. Logan “Grid-aware Large Scale Distributed Simulation of Agent-based Systems”, 5rd European Simulator Interoperability Workshop (Euro-SIW), 27-30 June 2005: Toulouse, France, SISO. Outstanding Paper Award Paper no: 05E-SIW-047, 10 pages
  • Jiang, M., Theodoropoulos, G., Anane, R., “A Framework for Distributed Simulation on a Grid”, Winter International Symposium on Information and Communication Technologies, ACM WISICT04, Hyatt Regency, Cancun, Mexico, January 5-8th, 2004. ACM International Conference Proceeding Series, ISBN 0-9544145-3-5.
  • Ming Jiang, R. Anane and G. Theodoropoulos, "Load balancing in distributed simulations on the grid," 2004 IEEE International Conference on Systems, Man and Cybernetics (IEEE Cat. No.04CH37583), The Hague, Netherlands, 2004, pp. 3232-3238 vol.4, doi: 10.1109/ICSMC.2004.1400838.

Papers on HLA_Agent

  • Lees, M., Logan, B., Theodoropoulos, G., “Distributed Simulation of Agent-based Systems in HLA”, ACM Transactions on Modeling and Computer Simulation Journal (TOMACS). Volume 17, Number 3, July 2007, ISSN 1049-3301, doi: 10.1145/1243991.1243992
  • Lees, M., Logan, B., Theodoropoulos, G., “Games, Agents and HLA”, Simulation Mod-elling Practice and Theory Journal, Elsevier, Special Issue on “Distributed Systems Modelling”, Vol. 14, Issue 6, August 2006, Pages752-767. doi: 10.1016/j.simpat.2005.10.007 
  • Lees, M., Logan, B., Oguara, T., Theodoropoulos, G., “Simulating Agent-Based Systems with HLA: The Case of Sim_Agent. PART II”, 2003 European Simulation Interoperability Workshop, 2003 Euro-SIW, Stockholm, Sweden, June 2003. Paper No: 03E-SIW-76 Outstanding Paper Award. 12 pages.
  • Lees, M., Logan, B., Theodoropoulos, G., “Simulating Agent-Based Systems with HLA: The Case of Sim_Agent”, 2002 European Simulation Interoperability Workshop, 2002 Euro-SIW, University of Westminster, Harrow Campus, Harrow, Middlesex, United Kingdom, June 2002. ISBN 1-930638-24-8, Paper No: 02E-SIW-51, Pages: 285-293

Papers on Interest Management for DVEs

  • E. S. Liu and G. K. Theodoropoulos, "An analysis of parallel interest matching algorithms in distributed virtual environments," 2013 Winter Simulations Conference (WSC), Washington, DC, USA, 2013, pp. 2889-2901, doi: 10.1109/WSC.2013.6721658.
  • Elvis Liu and Georgios Theodoropoulos, "Parallel Interest Matching Algorithm for Distributed-Memory Systems", 15th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT'11), Salford, Manchester, UK. Best Paper Award. DOI bookmark: 10.1109/DS-RT.2011.34
  • E. S. Liu and G. K. Theodoropoulos, "A fast parallel matching algorithm for continuous interest management," Proceedings of the 2010 Winter Simulation Conference, 5-8 December 2010, Marriott Waterfront Hotel, Baltimore, MD, USA, 2010, pp. 1490-1500, doi: 10.1109/WSC.2010.5679043.
  • Elvis Liu, Georgios Theodoropoulos, "A Continuous Matching Algorithm for Interest Management in Distributed Virtual Environments", the 24th Workshop on Principles of Advanced and Distributed Simulation (ACM/IEEE/SCS PADS) 2010, May 17-19, 2010, Atlanta, Georgia, USA.  DOI Bookmark: 10.1109/PADS.2010.5471665           
  • Elvis Liu, Georgios Theodoropoulos, “An Approach for Parallel Interest Matching in Distributed Virtual Environments”, 13th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2009) October 2009, Singapore.  Selected as the 2nd Best Paper. DOI Bookmark: 10.1109/DS-RT.2009.34
  • Minson, R., Theodoropoulos, G.,  “Load Skew in Cell-Based Interest Management Systems”, 12th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2008) October 2008, Vancouver, Canada, Pages: 43-50, ISBN ~ ISSN:1550-6525, 978-0-7695-3425-1, DOI Bookmark: 10.1109/DS-RT.2008.41.
  • Minson, R., Theodoropoulos, G.,  “Push-Pull Interest Management for Virtual Worlds”, 11th  IEEE International Symposium on Object/component/service-oriented Real-time distributed Computing, 5-7 May 2008, Orlando, Florida, USA. Pages: 189-194,  ISBN:978-0-7695-3132-8, DOI Bookmark: 10.1109/ISORC.2008.82.
  • Minson, R., Theodoropoulos, G.,  “An Evaluation of Push-Pull Algorithms in Support of Cell-Based Interest Management”, 11th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2007) October 2007, Chania, Greece, Pages: 39-47, ISBN ~ ISSN:1550-6525, 0-7695-3011-7, DOI Bookmark: 10.1109/DS-RT.2007.13
  • R. Minson and G Theodoropoulos, “A Design for Adaptive Support of Range Queries via Push-Pull Algorithms”, 21st International Workshop on Principles of Advanced and Distributed Simulation (PADS 2007), in conjunction with Federated Computing Research Conference FCRC 2007, June 12-15, 2007, San Diego, California, USA. Pages: 53-60, ISBN:0-7695-2898-8. DOI Bookmark: 10.1109/PADS.2007.11
  • Minson, R., Theodoropoulos, G., “Adaptive Interest Management via Push-Pull Algorithms”, 10th IEEE International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2006) October 2-6, 2006, Torremolinos, Malaga, Spain. Pages: 119 - 126, ISBN ~ ISSN: 1550-6525, 0-7695-2697-7. DOI Bookmark: 10.1109/DS-RT.2006.8
  • Minson, R., Theodoropoulos, G.,  “An Adaptive Interest Management Scheme for Distributed Virtual Envronments”, 19th ACM/IEEE/SCS Workshop on Principles of Advanced and Distributed Simulation (PADS 2005), June 1-3, 2005, Monterey, CA., USA  Pages: 273-281, ISBN~ISSN:1087-4097,0-7695-2383-8. DOI Bookmark: 10.1109/PA DS.2005.3