About me

I was born in County Kerry in south-western Ireland. As an undergraduate, I studied mathematics at Trinity College Dublin , won a foundation scholarship in 1993 and graduated in 1995 with a first class honours degree and a college gold medal. In 1998, I completed the M.Sc degree by research in mathematics at Trinity College Dublin on the topic of group-invariant Hilbert spaces of analytic functions in several complex variables. The work of my masters thesis was carried out under the supervision of Dr. Richard Timoney.

After spending some time working in industry and lecturing mathematics at the Institute of Technology, Tallaght, I commenced work on a Ph.D degree at the Hamilton Institute, National University of Ireland, Maynooth under the supervision of Professor Robert Shorten in 2001. I graduated with a Ph.D in 2004 and my thesis topic was the Lyapunov stability of switched linear systems.

From 2004 to 2007 I was a member of the Systems Biology team at the Hamilton Institute. Currently, I am a faculty member and co-ordinator of graduate studies at the Hamilton Institute with particular responsibility for co-ordinating the graduate programme in network mathematics: a joint initiative with the CTVR in Trinity College, which has run each summer since 2008.

Teaching

EE304: Probability and Statistics for Engineers

Current Research Interests

• Stability theory of positive and monotone dynamical systems and applications to epidemiology.

• Max Algebra and its applications to ranking schemes.

• Applications of graph theory in Biology and social network analysis.

Publications

Journal Publications and Preprints

1. Stability and positivity of equilibria for subhomogeneous cooperative systems, V.S. Bokharaie, O. Mason and F. Wirth, Nonlinear Analysis:Theory Methods and Applications, 74(17), pp. 6416-6426, 2011.

2. Spectral Properties of matrix polynomials over the max algebra, B. Benek Gursoy and O. Mason, Linear Algebra and its Applications, 435(7), pp. 1626-1636, 2011.

3. P1-max and S-max properties and asymptotic stability in the max algebra, B. Benek Gursoy and O. Mason, Linear Algebra and its Applications, 435(5), pp. 1008-1018, 2011.

4. Correction to ``D-Stability and Delay-independent stability of homogeneous cooperative systems'', V. S. Bokharaie, O. Mason and M. Verwoerd, IEEE Transactions on Automatic Control, 56(6), pp. 1489, 2011

5. D-Stability and Delay-independent stability of homogeneous cooperative systems, V. S. Bokharaie, O. Mason and M. Verwoerd, IEEE Transactions on Automatic Control, 55(12), pp. 2882-2885, 2010

6. Quadratic Lyapunov functions for systems with state-dependent switching, W. M. Griggs, C. K. King, R. N. Shorten, O. Mason and K. Wulff, Linear Algebra and its Applications, 433: 52-63, 2010

7. On copositive linear Lyapunov functions for sets of linear positive systems, F. Knorn, O. Mason and R. Shorten, Automatica, 45(8): 1943-1947, 2009

8. Observations on the stability properties of cooperative systems, O. Mason and M. Verwoerd, Systems and Control Letters, 58: 461-467, 2009

9. On computing the critical coupling coefficient for the Kuramoto model on a complete Bipartite graph, M. Verwoerd, O. Mason, SIAM Journal of Applied Dynamical Systems, 8(1): 417-453, 2009

10. An elementary proof of the Barker, Berman, Plemmons result on diagonal stability and extensions, R. N. Shorten, O. Mason, C. King, Linear Algebra and its Applications, 431(1):34-40, 2009

11. The role of control and systems theory in Systems Biology, P. Wellstead, E. Bullinger, D. Kalamatianos, O. Mason and M. Verwoerd, Annual Reviews in Control, 32:33-47, 2008

12. Global phase-locking in finite populations of phase-coupled oscillators, M. Verwoerd and O. Mason, SIAM Journal of Applied Dynamical Systems, 7(1): 134-160, 2008

13. Stability theory for switched and hybrid systems, R. N. Shorten, F. Wirth, O. Mason, K. Wulff, C. King-SIAM Review, 49(4): 545-592, 2007

14. Graph Theory and Networks in Biology, O. Mason and M. Verwoerd, IET Systems Biology, 1 (2), 89-119, 2007

15. On the Kalman-Yakubovich-Popov lemma and common Lyapunov solutions for matrices with regular inertia, O. Mason, R. Shorten and S. Solmaz, Linear Algebra and its Applications, 420, pp 183-197, 2007

16. Some results on quadratic stability of switched systems with interval uncertainty, E. Zeheb, O. Mason, S. Solmaz and R. Shorten, International Journal of Control, 80 (6), 825-831, 2007

17. On the stability of switched positive linear systems, L. Gurvits, R. Shorten and O. Mason, IEEE Transactions on Automatic Control, 52 (6), 1099-1103, 2007

18. On linear copositive Lyapunov functions and the stability of switched positive linear systems, O. Mason and R. Shorten, IEEE Transactions on Automatic Control, 52 (7), 1346-1349, 2007

19. Discussion on ``Multi-Layer Switching Control using Generalized Sampled-Data Hold Functions'', M. Verwoerd and O. Mason, European Journal of Control, 12 (5), 500-504, 2006

20. On the simultaneous diagonal stability of a pair of positive linear systems, O. Mason and R. Shorten, Linear Algebra and its Applications, 413, pp 13-23, 2006

21. A result on common quadratic Lyapunov functions, R.N. Shorten, K.S. Narendra and O. Mason, IEEE Transactions on Automatic Control, 48(1), pp 110-113, 2003

22. A unifying framework for the Circle Criterion and other quadratic stability criteria, R.N. Shorten, O. Mason, F. O Cairbre and P. Curran, International Journal of Control 77(1), pp 1-8, 2004

23. The geometry of convex cones associated with the Lyapunov inequality and the common Lyapunov function problem, O. Mason and R. Shorten, Electronic Journal of Linear Algebra, 12:42-63, 2005

24. Issues in the design of switched linear control systems: A benchmark study, D.J. Leith, R.N. Shorten, W.E. Leithead, O. Mason and P. Curran, International Journal of Adaptive Control and Signal Processing, 17, pp 103-118, 2003

25. On common quadratic Lyapunov functions for stable discrete-time LTI systems, O. Mason and R.N. Shorten, IMA Journal of Applied Maths, 59, pp 271-283, 2004

Conference Publications

• On common quadratic Lyapunov functions, R.N. Shorten, K.S. Narendra and O. Mason, IEEE Conference on Decision and Control, Las Vegas, 2002

• On common quadratic Lyapunov functions for pairs of stable discrete-time LTI systems, O. Mason and R.N. Shorten, American Control Conference, Denver, 2003

• A conjecture on the existence of common quadratic Lyapunov functions for positive linear systems, O. Mason and R. N. Shorten, American Control Conference, Denver, 2003

• A unifying framework for the Circle Criterion and other quadratic stability criteria, R. N. Shorten, O. Mason, F. O Cairbre and P. Curran, European Control Conference, Cambridge, 2003

• A wind turbine benchmark for hybrid system analysis and design, D.J. Leith, W.E. Leithead, O. Mason and R.N. Shorten, IFAC World Congress, Barcelona, 2002

• On the existence of common quadratic Lyapunov functions for single input single output systems, R. Shorten, K. S. Narendra, O. Mason and K. Wulff, Proceedings of the 12th Yale Workshop on Adaptive and Learning Systems, 2003

• Preliminary results on the stability of switched positive linear systems, L. Gurvits, R. Shorten and O. Mason, Mathematical Theory of Networks and Systems (MTNS), Leuven, 2004

• Some results on the stability of positive switched linear systems, O. Mason and R. Shorten, IEEE Conference on Decision and Control, 2004

• Towards a Systems Understanding of the Cerebral Motor Circuit, P. Wellstead, O. Mason, W. O Connor, K-H. Cho, E. Bullinger, O. Wolkenhauer and S. Duncan, Foundations of Systems Biology in Engineering (FOSBE), 2005

• Graph Theory and Networks in Biology, O. Mason and M. Verwoerd, International Conference on Systems Biology, Yokohama, 2006

• Protein Interaction Networks, Essentiality and Sensitivity, F. Knorn and O. Mason, Computational Methods in Systems Biology, Trento, 2006

• Quadratic and Copositive Lyapunov Functions and the Stability of Positive Switched Linear Systems, O. Mason and R. Shorten, American Control Conference, 2007

• Conditions for the Existence of Fixed Points in a Finite System of Coupled Oscillators, M. Verwoerd and O. Mason, American Control Conference, 2007

• On the growth of the largest component in duplication-divergence models of protein interaction networks, T. Rutjes, O. Mason and M. Verwoerd, Foundations of Systems Biology in Engineering (FOSBE), 2007

• Necessary and Sufficient Conditions for Joint Quadratic Lyapunov Function Existence: The Two-Dimensional Case, W. Griggs, C. King, R. Shorten, O. Mason and K. Wulff, Mediterranean Conference on Control and Automation, 2009

• Stability and D-stability for switched positive systems, O. Mason, V. Bokharaie and R. Shorten, 3rd International Symposium on Positive Systems, POSTA, 2009

• Applications of linear copositive Lyapunov functions for switched linear positive systems, F. Knorn, O. Mason and R. Shorten 3rd International Symposium on Positive Systems, POSTA, 2009

• On the D-stability of linear and nonlinear positive switched systems, V. S. Bokharaie, O. Mason and F. Wirth, Mathematical Theory of Networks and Systems (MTNS), 2010

• Spread of epidemics in time-dependent networks, V. S. Bokharaie, O. Mason and F. Wirth, Mathematical Theory of Networks and Systems (MTNS), 2010

Book Chapters

• Inference of protein function from the structure of interaction networks, O. Mason, M. Verwoerd and P. Clifford, to appear in "Structural Analysis of Complex Networks:Theory and Applications", Birkhauser, 2008

• Convex cones, Lyapunov functions and the stability of switched linear systems, R. Shorten, O. Mason and K.Wulff, Chapter in "Switching and Learning in Feedback Systems", Springer LNCS 3355, 2005

• Control of yaw-rate and sideslip in 4-wheel steering cars with actuator constraints, M. Vila- plana, O. Mason, D. Leith and W. Leithead, Chapter in "Switching and Learning in Feedback Systems", Springer LNCS 3355, 2005

Thesis

• Switched Systems, Convex Cones and Common Lyapunov Functions, 2004

Selected Recent Presentations

• Monotonicity and Riccati Differential Equations on Euclidean Jordan Algebras; Invited presentation at special session on positive systems, AIMS International Conference on Dynamical Systems, Differential Equations and Applications, TU Dresden, 2010

• Hybrid and Positive Systems in Biology and Elsewhere; Invited lectures at CIGENE, Norwegian University of Life Sciences, 2009

• Stability and D-stability for Positive Switched Systems; 3rd International Symposium on Positive Systems, Valencia, 2009

• Structure and Dynamics in Systems Biology - An Overview of Activities at the Hamilton Institute; Seminar at University College Cork, April 2008

• Cells, Signals and Synchronisation; Seminar at the University of Bristol, October 2007

• Switched Systems and Positivity; Seminar at the Technical University of Berlin, January 2007

• Lyapunov stability of time-varying positive linear systems; Seminar at the Free University of Berlin, November 2006

• Theory and analysis of interaction networks; Systems Biology Workshop at NUI Maynooth, September 2005

• Analysis of biological interaction networks: some recent results and open problems; Workshop on Data, Algorithms and Decision-making, Institute of Information Theory and Automation, Czech Academy of Sciences, Prague, December 2005

• Switched linear systems and common quadratic Lyapunov functions; Seminar Series of the Mathematics Department, University of Limerick, October 2005.

Miscellany

• I was a member of the organising committee of the Hamilton Institute workshop on Nonnegative matrices in 2004 and again in 2008.

• I served on the organising committee of the 2006 International Workshop on Systems Biology and on the committee for the 2008 workshop.

• I act as a reviewer for the IEEE Transactions on Automatic Control, the IEEE Transactions on Circuits and Systems, SIAM Journal of Control and Optimization, SIAM Journal of Matrix Analysis and its Applications, Linear Algebra and its Applications, IET Systems Biology and Systems and Control Letters. I also write reviews for Mathematical Reviews.

• I was one of the principal organisers of the Hamilton Mathematics Challenge: an online maths contest for secondary school students.