Preface:

Building on the success of previous CoSMoS workshops, we are pleased to be running the fourth CoSMoS as a satellite event of the 2011 European Conference on Artificial Life (ECAL11) in Paris, France. ECAL11 is an especially good fit for the CoSMoS workshop, examining critical properties of living and life-like systems and attracting a broad range of interdisciplinary researchers. The systems examined by these researchers are inherently complex, and various modelling and simulation techniques have become key to exploring and understanding their properties.

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.

The focus for the fourth CoSMoS workshop is on how complex systems simulations can begin to approach the scale of real-world complex systems. To complement this theme, our invited keynote speaker was Prof. Dirk Helbing from ETH Zürich, Switzerland, who is the scientific coordinator of FuturICT agship, which aims "to understand and manage complex, global, socially interactive systems, with a focus on sustainability and resilience".

The main session of the workshop is based on six full paper submissions:

Andrews et al. summarise the modelling concepts of the CoSMoS approach to complex systems simulations, and describe how these models can be related via their common metamodel, and how CoSMoS can be applied to engineering bio-inspired systems.

Evora et al. present a framework for simulating complex energy systems, and describe an agent-based model and simulation of household electricity demand which is used to investigate the load curve of 1000 households composed of different social groups.

McEwan et al. show how complex mathematical models can be expressed using techniques for specifying finite state machines, and how this enables a systems approach to be used at a coarser granularity than typically seen in systems biology.

Guest et al. explore the benefits and pitfalls of visualisation as a tool to aid understanding of complex systems, presenting a case-study of agent communication on the intra-individual, inter-individual and community scales

Droop et al. describe a hybrid multiscale modelling approach based on Petri net and object-oriented models, which is applied to a case-study on prostate cell division and differentiation.

Polack et al. complement the paper by Droop et al. by investigating the validity of the prostate cell simulation, and discussing more general issues of validating complex systems simulation for scientific research..

We also invited authors to submit abstracts, for presentation in a poster session. Abstracts for the following posters are presented in the proceedings:

Mancy et al. develop an alternative multiscale pairwise approximation approach for ecological modelling, and compare to a spatially explicit multiscale simulation.

Alden et al. present an agent-based simulation of Peyer's Patch formation developed following the CoSMoS approach, and explore how the simulation results relate back to observation of the real system

Eleftherakis et al. propose a framework to enable the engineering of emergent properties into artificial distributed networks, combining classical software engineering practices with multi-agent systems.

Clayton et al. explore the Go programming language for developing cellular automata type simulations, comparing Go to more established CSP based concurrent languages.

Our thanks go to our keynote speaker and to all the contributors for their hard work in getting these papers, abstracts and posters prepared and revised. All submissions received multiple reviews, and we thank the programme committee for their prompt, extensive and in-depth reviews. We would also like to extend a special thanks to the organising committee of ECAL11 for enabling our workshop to be co-located with this conference. 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(CoSMoS11,
  editor = "Susan Stepney and Peter H. Welch and Paul S. Andrews and Carl G. Ritson",
  title = "Proceedings of the 2011 Workshop on Complex Systems Modelling and Simulation,
          Paris, France, August 2011",
  booktitle = "Proceedings of the 2011 Workshop on Complex Systems Modelling and Simulation,
          Paris, France, August 2011",
  publisher = "Luniver Press",
  year = 2011
)