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Sample Dissertation Format Towards A Novel Unified Framework for Developing Formal, Network and Validated Agent-Based Simulation Models of Complex Adaptive Systems Muaz Ahmed Khan Niazi Computing Science and Mathematics School of Natural Sciences University of Stirling Scotland UK This thesis has been submitted to the University of Stirling In partial fulfillment for the degree of Doctor of Philosophy 2011 Abstract Literature on the modeling and simulation of complex adaptive systems (cas) has pri- marily advanced vertically in different scientific domains with scientists developing a variety of domain-specific approaches and applications. However, while cas researchers are inherently interested in an interdisciplinary comparison of models, to the best of our knowledge, there is currently no single unified framework for facilitating the development, comparison, communication and validation of models across different scientific domains. In this thesis, we propose first steps towards such a unified framework using a combination of agent-based and complex network-based modeling approaches and guidelines formulat- ed in the form of a set of four levels of usage, which allow multidisciplinary researchers to adopt a suitable framework level on the basis of available data types, their research study objectives and expected outcomes, thus allowing them to better plan and conduct their re- spective research case studies. Firstly, the complex network modeling level of the proposed framework entails the de- velopment of appropriate complex network models for the case where interaction data of cas components is available, with the aim of detecting emergent patterns in the cas under study. The exploratory agent-based modeling level of the proposed framework allows for the development of proof-of-concept models for the cas system, primarily for purposes of exploring feasibility of further research. Descriptive agent-based modeling level of the proposed framework allows for the use of a formal step-by-step approach for developing agent-based models coupled with a quantitative complex network and pseudocode-based specification of the model, which will, in turn, facilitate interdisciplinary cas model com- parison and knowledge transfer. Finally, the validated agent-based modeling level of the proposed framework is concerned with the building of in-simulation verification and vali- dation of agent-based models using a proposed Virtual Overlay Multiagent System approach for use in a systematic team-oriented approach to developing models. The pro- posed framework is evaluated and validated using seven detailed case study examples selected from various scientific domains including ecology, social sciences and a range of complex adaptive communication networks. The successful case studies demonstrate the potential of the framework in appealing to multidisciplinary researchers as a methodologi- cal approach to the modeling and simulation of cas by facilitating effective communication - ii - and knowledge transfer across scientific disciplines without the requirement of extensive learning curves. - iii - Declaration I, Muaz Niazi hereby declare that this work has not been submitted for any other degree at this University or any other institution and that, except where reference is made to the work of other authors, the material presented is original. Some portions of the thesis chap- ters have been published as follows: • Parts of Chapter 3 in [2], [3]. • Parts of Chapter 4 in [4]. • Parts of Chapter 5 in [5], [6]. • Parts of Chapter 6 in [7-9]. Qasim Siddique helped in some of the simulation experiments. Some ideas of research simulation were formulated based on ad- vice from Dr. Saeed Bhatti and Dr. Abdul Rauf Baig. Muaz Niazi - iv - Acknowledgements This thesis would not have been possible without the help and support of a large number of individuals. First and foremost, I would like to thank my family members, especially my beloved parents, who have endured my absence during my research and helped me tre- mendously in all ways possible. Without your continued help, support and guidance, this would never have been possible. Thank you. I am deeply indebted to my principal supervisor and founding Head of our COSIPRA Lab, Dr. Amir Hussain who provided stimulating advice, guidance and encouragement to me every step of the way. I would like to thank Kamran, Dr. Erfu, Thomas, Rozniza, Erik and Andrew from the COSIPRA lab. I would also like to thank Kerstin Rosee who, on be- half of Dr. Amir, would keep me on my toes by requiring regular updates. Writing updates always pushed me, by forcing me to quantify my progress and obtain critical feedback on a periodic basis. I would also like to thank Ian MacLellan from the International Office. Fi- nally, I would especially like to thank my Examiners Dr. Keshav Dahal (from Bradford University) and Dr. Savitri Maharaj for their constructive criticism and helpful comments, which helped me considerably in shaping up the thesis in a much better way than I had originally planned. - v - Table of Contents Abstract ................................................................................................................................. ii Declaration ........................................................................................................................... iv Acknowledgements ............................................................................................................... v Table of Contents ................................................................................................................. vi List of Figures ..................................................................................................................... xii List of Tables ...................................................................................................................... xvi List of Abbreviations ......................................................................................................... xvii 1 Introduction ...................................................................................................................... 1 1.1 Modeling cas ............................................................................................................ 2 1.2 Motivation ................................................................................................................ 9 1.3 Aims and Objectives .............................................................................................. 10 1.4 Original Contributions ........................................................................................... 11 1.5 Proposed framework for the Modeling and Simulation of cas ............................... 13 1.5.1 Overview of the proposed framework .............................................................. 13 1.5.2 Proposed framework levels formulated in terms of cas study objectives ......... 15 1.5.3 Proposed framework levels formulated in relation to available data types ....... 18 1.6 Publications ............................................................................................................ 19 1.6.1 Refereed Conferences and Workshops .............................................................. 19 1.6.2 Published Journal papers ................................................................................... 19 1.7 Overview of the thesis ............................................................................................ 20 1.7.1 Overview of case studies .................................................................................. 20 1.7.2 Outline of the Thesis ......................................................................................... 21 2 Complex Adaptive Systems: Background and Related Work ........................................ 23 2.1 Overview ................................................................................................................ 23 2.2 Complex Adaptive Systems (cas)........................................................................... 23 2.2.1 The Seven Basics of cas .................................................................................... 26 2.2.2 Emergence ......................................................................................................... 29 2.3 Examples of cas ..................................................................................................... 30 2.3.1 Natural cas example 1: Cas in plants ................................................................ 30 2.3.2 Natural cas example 2: Cas in social systems ................................................... 31 2.3.3 Artificial cas example 1: Complex adaptive communication networks ............ 34 2.3.4 Artificial cas example 2: Simulation of flocking boids .................................... 36 - vi - 2.4 Modeling cas .......................................................................................................... 37 2.4.1 Complex Network Modeling ............................................................................ 38 2.4.1.1 Complex Network Methods ...................................................................... 39 2.4.1.2 Theoretical basis ........................................................................................ 40 2.4.1.3 Centralities and other Network measures .................................................. 41 2.4.1.4 Software tools for Complex Networks ...................................................... 44 2.4.2 Agent-based Modeling and Agent-based
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