Preface:

Building on the success of the first CoSMoS workshop, we are pleased to be running the second CoSMoS workshop in association with the 8th International Conference on Artificial Immune Systems (ICARIS), in York, UK. The immune system exemplifies a complex system --- immune regulation and protection against harmful micro-organisms emerges from the interaction of large populations of different immune cells. Artificial immune systems seek to understand and exploit the properties of the real immune system. As such, the modelling and simulation of complex systems fits well within the scope of the ICARIS series of conferences.

The genesis of the CoSMoS workshop is the similarly-named CoSMoS research project, a four year EPSRC funded research project at the Universities of York and Kent. The project aims are stated as:

The project will build capacity in generic modelling tools and simulation techniques for complex systems, to support the modelling, analysis and prediction of complex systems, and to help design and validate complex systems. Drawing on our state-of-the-art expertise in many aspects of computer systems engineering, we will develop CoSMoS, a modelling and simulation process and infrastructure specifically designed to allow complex systems to be explored, analysed, and designed within a uniform framework.

As part of the project, we are running annual workshops, to disseminate best practice in Complex Systems modelling and simulation. To allow authors the space to describe their systems in depth we put no stringent page limit on the submissions.

We are delighted this year to welcome the world renowned immunologist Irun Cohen from the Weizmann Institute of Science, Israel as our keynote speaker. In recent years Cohen has worked closely with David Harel, a computer scientist also at the Weizmann Institute of Science. Together they have led the way in developing predictive models and simulations of real complex systems, notably the immune system. In the first paper presented here, Cohen and Harel reflect on their experiences of coming from very difference disciplines to work together in an truly inter-disciplinary setting.

Continuing the immune system theme, Read, Timmis, Andrews and Kumar present a model of the autoimmune disease Experimental Autoimmune Encephalomyelitis in mice. The model is the first step in producing a predictive simulation of the disease to provide insight into the real system. Tools from the unified modelling language are used to express the model, which provides insight into UML's expressive capabilities when applied to complex system modelling.

Hone examines the issue of using numerical integration methods to analyse mathematical models formulated in terms of differential equations, focussing on a number of non-standard discretisation methods that have the potential to be extremely useful in modelling biological systems.

Hoverd and Stepney consider the design of complex systems and the role played by the environment in the interactions of complex systems agents. They present an abstract software architecture for environment-oriented complex system simulations, providing examples of how this could be implemented.

Nash and Kalvala focus on the use of process calculi and the well studied aggregation behaviour of the Dictyostelium discoideum amoeba, showing how the pi-Calculus can be used to model various aspects of the aggregation behaviour such as cell locality and intra-cellular signal transduction.

Finally, Ghetiu, Alexander, Andrews, Polack and Bown examine the issue of applying argumentation techniques used for safety critical systems to complex system. The work presented here shows how these techniques can be used to argue that two different implementations of a complex system simulation are adequately equivalent.

Our thanks go to Irun Cohen for presenting his keynote and to all the contributors for their hard work in getting these papers prepared and revised. We thank the programme committee for their prompt, extensive and in-depth reviews of all the papers submitted. We would also like to thank Bob French and Mandy Kenyon from the Research Support Office in the Department of Computer Science, University of York for their invaluable assistance behind the scenes. We hope that readers will enjoy this set of papers, and come away with insight on the state of the art, and some understanding of current progress in Complex Systems Modelling and Simulation.

@proceedings(CoSMoS09,
  editor = "Susan Stepney and Peter H. Welch and Paul S. Andrews and Jon Timmis",
  title = "Proceedings of the 2009 Workshop on Complex Systems Modelling and Simulation,
          York, UK, August 2009",
  booktitle = "Proceedings of the 2009 Workshop on Complex Systems Modelling and Simulation,
          York, UK, August 2009",
  publisher = "Luniver Press",
  year = 2009
)