Overview
  Qualifications
  Research Statement
  Work Experience
  Publications
  Awards and Grants
  Technical and Professional Skills
  Referees
Joseph Troy LIZIER
B.Sc.(Adv) B.E.(Hons I & Medal) Ph.D.
joseph.lizier at gmail.com
+61 2 8005 5769 (AU); +49 176 991 04523 (DE)

Overview


Qualifications


Research Statement

My primary research interest lies in the information dynamics of distributed computation in complex systems. The physics or nature of distributed computation has long been of interest in complex systems, artificial life, bioinformatics and computational neuroscience. Systems in all of these domains are often described in terms of memory, communication or signalling and processing. The hypothesis I am following is that if we can describe and quantify distributed computation in these terms, with particular attention to their dynamics, then we will be better able to understand computation in nature and its sources of complexity. It will also allow us to answer meaningful questions about computation in complex systems; e.g. when and how much information is transferred between two brain regions. This approach should also provide insights on how to better design distributed computing systems.

I have produced a framework to quantitatively define each of these distributed operations on information during computation. Formally they are information storage, transfer and modification, and collectively referred to as information dynamics. They are measured information-theoretically, and are called dynamics since they are studied on a local scale in space and time. I have introduced new measures including the active information storage and separable information (for modification), localised existing measures including the transfer entropy and excess entropy, and compared to other related measures including causal information flow (see papers [11,16,18,29] below).

Importantly, the framework has provided quantitative evidence for several long-held conjectures regarding distributed computation in theoretical systems, such as the roles of emergent structures in cellular automata [11,16,18,29]. I have also studied whether these computational properties are maximised in order-chaos phase transitions [13,24,25,31]. Further, I have produced a Java toolkit to implement the measures, and applied them to study computation in models of gene regulatory networks [13,24,25], artificial life systems [12,14], and in computational neuroscience [19,20,27,28], with promising results in each domain. The existing work shows the approach is theoretically sound and has strong potential for making inroads for complex systems science into many disciplines.

Currently I am studying how the physical structure of complex networks relates to their computational capabilities [19,22,25]. For example, I have found that ordered networks tend to be biased towards information storage behaviour, random networks tend to be biased towards information transfer behaviour, while small-world networks exhibit something of a balance between these operations [25]. I am also concentrating on applications to complex networks in computational neuroscience [19,27,28], e.g. examining task-based differences in spatiotemporal information transfer patterns in brain imaging data [27].

I have successfully collaborated on this work with researchers from the Max Planck Institute for Mathematics in the Sciences, CSIRO ICT Centre, The University of Sydney, Indiana University, Bernstein Center for Computational Neuroscience, Osaka University, University of Delaware, and Doshisha University.


Work Experience

Postdoctoral Researcher Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany (Dec 2010 to present).
I am currently based in Prof. Juergen Jost's Dynamical Systems and Network Analysis, and Cognition and Neurosciences groups. My postdoctoral work aims to investigate how information is manipulated in complex networks, harnessing the expertise at MPI regarding dynamical systems, complex networks, synchronisation, information theory and computational neuroscience. Read more about my current research in my Research Statement above, and at http://lizier.me/joseph/.

Research Associate (part-time) The University of Sydney (July 2010 to Nov 2010).
Writing up papers from my thesis work, and co-supervising an honours student.

Senior R&D Engineer (part-time) Seeker Wireless (Dec 2006 to Oct 2010).
I assisted with research and development for the SIM toolkit client-side component of Seeker's mobile handset location solution. This included prototype work for new features, development on the production code-base, testing and investigation of specific handset compatibility issues, development of automatic build and deployment tools, and some Java web application development.

Casual Academic Tutor Department of Computing, and Department of Electronics, Macquarie University (Aug 2006 to Nov 2006).
I tutored the courses ELEC116 Introduction to Electronic Systems (for 1st year students), and COMP333 Algorithm Theory and Design (for 3rd year students), which involved running weekly tutorials, laboratories, and marking of assignments. My teaching evaluations are available on request.

Senior Research Technologist Telstra Research Laboratories (Jan 2001 to Jan 2006).
My role at TRL covered a wide variety of technologies, in particular service management, mobile telecommunications and XML web services. I was involved across all research activities including prototype development, consulting on emerging technologies, product trials and vendor evaluations. My roles in these projects ranged from regular team member to technical lead and project leader.
The project areas I was involved in, and my roles in these projects, included:

Tutor School of Electrical and Information Engineering, The University of Sydney (Jul to Nov 2000).
I tutored the course ELEC1102 Foundations of Electrical Circuits (for 1st year students), which involved running weekly 2 hour mini-lecture/tutorials for classes of 60 students, as well as marking of weekly assignments. The course lecturer, Dr. Jamie Evans, wrote in a letter of recommendation - "Quite simply, I do not believe the students could have had a better tutor."

Industrial Experience Student Chancellor's Industry Scholarship in Engineering
This involved summer vacation placements with: Telstra Research Laboratories (Sydney, Dec 1999 to Feb 2000, developing service management software), BHP Steel (Port Kembla, Dec 1997 to Feb 1998, designing earth leakage detection and overhead crane warning systems), and Integral Energy (Seven Hills, Dec 1996 to Feb 1997, database management).

Summer Vacation Research Student School of Physics, The University of Sydney (Dec 1998 to Jan 1999)
I assisted in Dr. Ferg Brand’s research, designing and conducting experiments to investigate Bragg reflection of millimetre waves from an illuminated semiconductor.

Tutor Casual (1996 to 1999) and with Five Senses Education (1997)
One-on-one tutor for both high school and university students for Maths and Physics.


Selected Publications

See and download all publications (plus abstract-only work) at http://lizier.me/joseph/publications/.
See also my list of presentations on these pulications at http://lizier.me/joseph/presentations/. A selection of publications is as follows: (show all)

  1. J.T. Lizier, F. M. Atay and J. Jost, "Information storage, loop motifs and clustered structure in complex networks", MPI MIS Preprint 71/2011, 2011.
  2. M. Prokopenko, J.T. Lizier, O. Obst and X.R. Wang, "Relating Fisher information to order parameters", Physical Review E, vol. 84, no. 4, 041116, 2011.
  3. J.T. Lizier, S. Pritam and M. Prokopenko, "Information dynamics in small-world Boolean networks", Artificial Life, vol. 17, no. 4, pp. 293-314, 2011.
  4. X. R. Wang, J.T. Lizier and M. Prokopenko, "Fisher information at the edge of chaos in random Boolean networks", Artificial Life vol. 17, no. 4, pp. 315-329, 2011.
  5. J.T. Lizier, M. Prokopenko and A.Y. Zomaya, "Coherent information structure in complex computation", accepted by Theory in Biosciences special issue on Guided self-organization, 2010, to be published.
  6. J. Boedecker, O. Obst, J.T. Lizier, N.M. Mayer, M. Asada, "Information processing in echo state networks at the edge of chaos", accepted by Theory in Biosciences special issue on Guided self-organization, 2010, to be published.
  7. J.T. Lizier, J. Heinzle, A. Horstmann, J.-D. Haynes, M. Prokopenko, "Multivariate information-theoretic measures reveal directed information structure and task relevant changes in fMRI connectivity", Journal of Computational Neuroscience (Special issue on "Methods of Information Theory in Neuroscience Research"), vol. 30, pp. 85-107, 2011.
  8. J.T. Lizier, M. Prokopenko and A.Y. Zomaya, "Information modification and particle collisions in distributed computation", Chaos: An Interdisciplinary Journal of Nonlinear Science for the Focus issue on "Intrinsic and Designed Computation: Information processing in dynamical systems", vol. 20, no. 3, 037109, 2010.
  9. J.T. Lizier, and M. Prokopenko, "Differentiating information transfer and causal effect", European Physical Journal B, vol. 73, no. 4, pp. 605-615, 2010.
  10. J.T. Lizier, M. Prokopenko and A.Y. Zomaya, "Local Information Transfer as a Spatiotemporal Filter for Complex Systems", Physical Review E, vol. 77, 026110, 2008.
  11. J.T. Lizier and G.E. Town, "Splice Losses in Holey Optical Fibers", IEEE Photonics Technology Letters, Vol. 13, No. 8, pp. 794-796, 2001.
  12. G.E. Town and J.T. Lizier, "Tapered holey fibers for spot-size and numerical aperture conversion", Optics Letters, Vol. 26, No. 14, pp. 1042-1044, 2001

Awards and Grants


Technical and Professional Skills


Referees