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# Research

I am an RA in the AESOP research group in the Department of Computing at Imperial College. See my publications there. Various files and additional data referenced by my Ph. D. thesis are available on this page.

My research is concerned with the analysis of very large stochastic performance models with specific application to the performance modelling of computer and communication networks.

My CV is available as a PDF or on the web. For a more detailed version, please email me to request it.

## Invited talks / Tutorials

- University of Illinois at Urbana-Champaign - Coordinated Science Laboratory (March 2013) - Seminar: Scalable Performance Analysis of Massively Parallel Stochastic Systems (slides)
- Center for the Mathematics of Information, Caltech (February 2013) - Postdoctoral Seminar Series: Some Theory and Applications of Martingales for Performance Analysis
- Budapest University of Technology and Economics (BME) - Seminar Series on Advances in Telecommunications, Networking and Computing (November 2012) - Seminar: Scalable Performance Analysis of Massively Parallel Stochastic Systems (slides)
- Edinburgh University - Laboratory for Foundations of Computer Science (October 2012) - Seminar: Scalable Performance Analysis of Massively Parallel Stochastic Systems (slides)
- 12th Joint ACM SIGMETRICS / Performance Conference 2012 - Tutorial: Basic Theory and some Applications of Martingales
- 11th INFORMS Telecommunications Conference 2012 - Doctoral Dissertation Award Finalist Talk (slides)

## Group seminars

- Mean-field analysis for large-scale GSMPs and interacting fluid models (29th November 2012) (slides)

## Publications

### Journal papers

- Richard A. Hayden, Jeremy T. Bradley, Allan Clark Performance specification and evaluation with Unified Stochastic Probes and fluid analysis, IEEE Transactions on Software Engineering, to appear 2012
- Richard A. Hayden, Anton Stefanek, Jeremy T. Bradley, Fluid computation of passage-time distributions in large Markov models, Theoretical Computer Science, 2012
- Richard A. Hayden, Jeremy T. Bradley, A fluid analysis framework for a Markovian process algebra, Theoretical Computer Science, 2010
- Richard A. Hayden, Jeremy T. Bradley, Evaluating fluid semantics for passive stochastic process algebra cooperation, Performance Evaluation, 2009

### International conference and workshop papers

- Richard A. Hayden, Mean field for performance models with deterministically-timed transitions, QEST 2012, 9th International Conference on Quantitative Evaluation of Systems, London, September 2012
- Matej Kohut, Anton Stefanek, Richard A. Hayden, Jeremy T. Bradley, Specification and efficient computation of passage-time distributions in GPA, QEST 2012, 9th International Conference on Quantitative Evaluation of Systems, London, September 2012
- Anton Stefanek, Richard A. Hayden, Marc Mac Gonagle, Jeremy T. Bradley, Mean-field analysis of Markov models with reward feedback, ASMTA 2012, 19th International Conference on Analytic and Stochastic Modelling Techniques and Applications, Grenoble, June 2012
- Anton Stefanek, Richard A. Hayden, Jeremy T. Bradley, GPA - A tool for fluid scalability analysis of massively parallel systems, QEST 2011, 8th International Conference on Quantitative Evaluation of Systems, Germany, September 2011
- Anton Stefanek, Richard A. Hayden, Jeremy T. Bradley, Fluid analysis of energy consumption using rewards in massively parallel Markov models, ICPE 2011, 2nd ACM/SPEC International Conference on Performance Engineering, Germany, March 2011
- Anton Stefanek, Richard A. Hayden, Jeremy T. Bradley, A new tool for the performance analysis of massively parallel computer systems, QAPL 2010, 8th Workshop on Quantitative Aspects of Programming Languages, Cyprus, March 2010
- Richard A. Hayden, Jeremy T. Bradley, Shared Transaction Markov Chains for Fluid Analysis of Massively Parallel Systems, MASCOTS 2009, 17th Annual Meeting of the IEEE International Symposium on Modelling, Analysis and Simulation of Computer and Telecommunication Systems, United Kingdom, September 2009
- Richard A. Hayden, Jeremy T. Bradley, Fluid semantics for passive stochastic process algebra cooperation, VALUETOOLS 2008, 3rd International Conference on Performance Evaluation Methodologies and Tools, Greece, October 2008
- Jeremy T. Bradley, Richard A. Hayden, William Knottenbelt, Tamas Suto Extracting response times from fluid analysis of performance models, SIPEW 2008, SPEC International Performance Evaluation Workshop, Germany, June 2008
- Andrew Cheadle, Tony Field, John Ayres, Neil Dunn, Richard A. Hayden, Johan Nyström-Persson, Visualising dynamic memory allocators, ISMM 2006, International Symposium on Memory Management, Canada, June 2006.

### Short journal papers

- Richard A. Hayden Mean-field approximations for performance models with generally-timed transitions, SIGMETRICS Performance Evaluation Review, 2011
- Anton Stefanek, Richard A. Hayden, Jeremy T. Bradley Fluid computation of the performance-energy trade-off in large scale Markov models, SIGMETRICS Performance Evaluation Review, 2011
- Jeremy T. Bradley, Nigel Thomas, Richard A. Hayden, Anton Stefanek, Invited Response to Computer Journal Lecture by Prof. J. Hillston, The Computer Journal, 2012

### National conference and workshop papers

- Richard A. Hayden, Convergence of ODE approximations and bounds on performance models in the steady-state, PASTA 2010, 9th Workshop on Process Algebra and Stochastically Timed Activities, September 2010
- Anton Stefanek, Richard A. Hayden, Jeremy T. Bradley, Hybrid analysis of large scale PEPA models, PASTA 2010, 9th Workshop on Process Algebra and Stochastically Timed Activities, September 2010
- Anton Stefanek, Richard A. Hayden, Jeremy T. Bradley, GPA - Tool for rapid analysis of very large scale PEPA models, UKPEW 2010, 26th UK Performance Engineering Workshop, July 2010
- Richard A. Hayden, Jeremy T. Bradley, A functional central limit theorem for PEPA, PASTA 2009, 8th Workshop on Process Algebra and Stochastically Timed Activities, August 2009
- Jeremy T. Bradley, Richard A. Hayden, William Knottenbelt, Tamas Suto, Extracting fluid response times from PEPA models, PASTA 2008, 7th Workshop on Process Algebra and Stochastically Timed Activities, July 2008
- Richard A. Hayden, Jeremy T. Bradley, ODE-based general moment approximations for PEPA, PASTA 2008, 7th Workshop on Process Algebra and Stochastically Timed Activities, July 2008
- Richard A. Hayden, Jeremy T. Bradley, Fluid-flow solutions in PEPA to the state space explosion problem, PASTA 2007, 6th Workshop on Process Algebra and Stochastically Timed Activities, July 2007