Tuesday, November 17, 2009


So I've been seduced by micro-blogging lately instead of doing much writing over here. It makes me think of the trend away from test match cricket towards the twenty-20 variety ...

Anyway. I have to say that I've been enjoying getting into it. Follow me over at twitter: @jlizier

Writing up

Well, that came around much more quickly than I was expecting. The last three and a half years doing my PhD have been really enjoyable, so on one hand writing up my thesis makes me a little sad to be finishing up. On the other hand, it's quite exciting and I'm looking forward to seeing the bound, finished product.

Anyway, I'm well on the way at the moment, with about 4.5 chapters out of the 6 technical chapters done. And I'm only just hitting the writer's block stage; well that's an overstatement, I'm just having a little trouble getting the right tone on this chapter. Nothing serious. I'm still on track for a pre-Christmas submission. As I said to my supervisors, the only risk is that they won't provide the feedback fast enough :).

I'm looking forward to a nice holiday over Christmas and January, then who knows where I'll end up next year. I put my first post-doc application in last week, I'm working on another one, and planning to put in a local application early next year. Watch this space.

Monday, November 16, 2009

Neural Computation discussion group

Today I'm just going to run a quick advertisement for a new series we're starting in our discussion group on"Neural Computation". It's on Fridays @ 2 pm at CSIRO Marsfield (north-west Sydney), but is open to anyone from outside who is interested.

More details, including the schedule of talks, is available at http://www.prokopenko.net/entropy.html

As it happens, stumbling upon a link for these talks and subsequently coming along to them is how I met Mikhail which led to me starting my PhD. So if you're interested in the area, do come along as you never know where it might lead you!

Thursday, October 1, 2009

Funny stunt

Here I was thinking that I was procrastinating about writing up my PhD. Not as much as these guys:
One of the funniest things I've seen for a while ...

Wednesday, September 16, 2009

Apology to Turing

Not mine, the British government's.

Better late than never.

Saturday, August 22, 2009

Information, computation and complex systems workshop

A quick post to advertise the Information, Computation and Complex Systems satellite meeting, which is part of ECCS 09.

From the workshop page:
This workshop will bring together mathematicians and scientists to discuss methods and applications of information theory to complex systems. This includes the perspective of complex systems as computers.
The question of good measures of complexity alone is vital for complex systems research. Many proposals have been made, quite a few based on information theory. The workshop addresses the following topics:
  1. Mathematics of information theoretic tools for complex systems
  2. Information theory applied to complex systems
  3. Complex systems as information processors

The workshop will provide a forum for discussing the various existing information-theoretic and computation-theoretic tools, and their use in complex systems.
The focus will be on the mathematics of information and computation theory applied to complex systems. We encourage both theorists and experimentalists to attend, with either an information theoretic approach or a need for an information theoretic approach.

I think this will be a really interesting workshop, as it directly relates to the focus of my PhD. The invited presentations should be quite good. I'm hoping to get the opportunity to present my own approach of the local information dynamics of distributed computation in complex systems, and hope to meet some people there with the need for this kind of approach.

Submissions are apparently open until Mon 24/8/09, hope to see you there.

Update 1/9/09 - my submission "Coherent local information dynamics in complex computation" was accepted, so I'm now looking forward to presenting at ICCS. The schedule has been posted.

Wednesday, July 8, 2009

The Ashes 2009

Tonight (Australian time) marks the start of the 2009 Ashes series in the UK. For the uninitiated, The Ashes is the "trophy" for Australia vs England cricket series. These series occur roughly every two years, with a series hosted by each country each four years. For an Australian player or fan, an Ashes series in England is as good as it gets.

To say I am looking forward to the coverage is an understatement. I would really love to get to England for the series one day. I'll be nearby in Germany during the last game of the series this year, but unfortunately all of the tickets are sold out.

As I'm sitting here watching the first few overs, I've been thinking about how I can almost mark progress in my life by what I was doing while watching the Ashes from England every four years. In 1989 I was just finishing primary school. I hadn't been interested in or playing cricket for long, but it sure took up a lot of my thinking. In 1993 I was mid-way through high school, and by this point was taking my studies fairly seriously as I had realised what I could achieve academically. I remember watching the games up late after coming home some of the first times I was allowed to go out with my friends at night. By 1997 I was a couple of years into uni, really enjoying engineering. I was also going out with my wife (then girlfriend) by then and my enduring memory of that series is watching it at her place after everyone else was asleep. 2001 was a big year for growing up: first full-time job, moving out with my girlfriend and thinking about getting married. It was nice watching that series late at night in a place I could call my own. Much better was 2005, when I could watch it in an apartment I owned rather than rented. By this time, we were married, and I had established myself at work though I was thinking a lot about how to go about doing a PhD as I was watching the games. This time, I'm sitting in our own house, am writing up my thesis, and my wife has begun her PhD studies. This time around I'll be occupied by what I/we are going to do next year once I'm finished. I wonder where I will be in four years time?

Monday, June 29, 2009

The information dynamics of cascading failures in energy networks

Disclaimer: shameless self-promotion follows.

So our submission:
Joseph T. Lizier, Mikhail Prokopenko, David J. Cornforth, "The information dynamics of cascading failures in energy networks"
to ECCS 2009 was accepted, and I'll be presenting it in the Policy, Planning and Infrastructure track currently on the Friday morning of the conference.

The abstract is as follows:
Small failures in electrical energy networks can lead to cascading failures that cause large and sustained power blackouts. These can disrupt important services and cost millions of dollars. It is important to understand these events so that they may be avoided. We use an existing model for cascading failures to study the information dynamics in these events, where the network is collectively computing a new stable distribution of flows. In particular, information transfer and storage across the network are shown to exhibit sensitivity to reduced network capacity earlier than network efficiency does, and so could be a useful indicator of critical loading. We also show that the local information dynamics at each node reveals interesting relationships between local topological features and computational traits. Finally, we demonstrate a peak in local information transfer in time coinciding with the height of the cascade's spread.
In a nutshell, this paper describes an application of our framework for the information dynamics of distributed computation to the phenomena of cascading failures on networks. The focus is on energy networks, though the results are applicable to other types of networks, e.g. transport.

Information dynamics may at first not seem applicably to cascading failures, but there are a few good reasons for the application here. First, cascading failures are akin to damage spreading phenomena, and both are often cited as mechanisms of information transfer in networks: it is useful to explore this quantitatively. Further, when a cascading failure occurs, the network is actually computing a new stable state (or attractor), so quantifying the information dynamics is a direct study of this computation. To underline all that, I really like this quote from Melanie Mitchell's new book:
The phenomena of cascading failures emphasizes the need to understand information spreading and how it is affected by network structure.
Primarily, the results show that we get maximisations of information transfer and storage in the network near the critical phase, aligning with our findings in Random Boolean Networks (RBNs) in a paper at ALifeXI last year. We also find some interesting relationships between topological properties of the individual nodes and their own local information dynamics.

From here, I'll be combining this work with that on RBNs in my PhD thesis, and probably seeking to make a journal submission from their combination.

Thursday, June 18, 2009

Second International Workshop on Guided Self-Organisation (GSO-2009)

Just a quick post to advertise The Second International Workshop on Guided Self-Organisation (GSO-2009) which I'm planning on attending in August.

A few pertinent clips from the workshop's website:

"... by its very nature, self-organization more often than not has its own way. To be useful in practice, methods of guiding self-organization towards prespecified goals have to be developed. Adding and controlling constraints provides one possibility to this end.
Many properties of self-organisation can be characterised formally (e.g., information-theoretically). However, the lack of agreement of what is meant by complexity, constraints, etc, as well as a common methodology across multiple scales leaves any definition of self-organisation somehow vague, indicating a clear gap. Filling this gap and identifying common principles of guidance are the main themes of GSO-2009. The workshop will put particular emphasis on principles based on information flows through the perception-action loop of embodied systems."

GSO-2008 was a really interesting week, so am hoping for the same level of inspiration this time round.

Registration is open, hope to see you there.

Monday, April 20, 2009

Directed information structure

The good news is that we recently received a notice of acceptance of an abstract we submitted to CNS*2009 (July 18-23) in collaboration with John-Dylan Haynes and Jakob Heinzle from the Bernstein Centre for Computational Neuroscience (BCCN) in Berlin.

Titled "Directed information structure in inter-regional cortical interactions in a visuomotor tracking task", it deals with a method for identifying directed information structure between distinct regions (of variables) in a large multi-variate set. The method identifies an interesting hierarchical structure for the given visuomotor task.

My supervisor will be at CNS to present the poster, and the abstract will be included in a supplement to BMC Neuroscience soon. We're currently working on a more complete journal paper reporting on this experiment.

CNS*2009 should be a good meeting, particularly the Methods of Information Theory in Computational Neuroscience workshop. Wish I was going!

Thursday, April 2, 2009

ECAL and ECCS calls for papers

Just thought I'd share two calls for papers for conferences that I will be / have submitted to this year.

The European Conference on Complex Systems (ECCS09) will be held from 21-25 September 2009, at the University of Warwick, UK. I've never been to ECCS before, but I've heard good things from several people about it. I like the way it appears to be a real melting pot of all areas of complex systems science, so I'm looking forward to seeing some interesting perspectives there. On that note, I think there will be some interesting applications related papers there, e.g. in the Policy, Planning and Infrastructure track. I also like the tiered submission structure, where you can submit 2, 6 or 15 page papers, and (if accepted) get a poster, 20 min or 40 min presentation: it gives you choice, and appropriate relative reward for work. We've submitted a paper on cascading failures in energy networks (more details if we're accepted). The first submission deadline has passed, though they have two more deadlines coming up (19/4 and 3/5): apparently slots will be filled on a "first arrival - frist serve policy".

The 10th European Conference on Artificial Life (ECAL2009) will be held from September 13-16 2009 in Budapest, Hungary. I was at the last ECAL in Lisbon in 2007 and thoroughly enjoyed it. It's a good crowd, with a nice mix of biologists and computer scientists. We're currently working on a paper combining some of my work on information dynamics with my PhD colleague Mahendra Piraveenan's work on network topological measures: this is something I had wanted to do for a while, but isn't in the form I thought it would be (nothing wrong with that though). More details if we're accepted. Anyway, ECAL are now following the lead of ALifeXI in allowing abstract only submissions (which I think is fine in principle), and allowing both to have presentation slots (this I'm not sure about - I had the impression that some, not all, of what came through the abstract only channel was under-prepared; I prefer the ECCS approach). Paper submission is by April 30.

Hope to see you there! (assuming we get accepted...)

Thursday, March 26, 2009

Save the .au internet

The Australian Government is proposing an internet filter for all content coming down Australian people's lines. I don't disagree with the aim of stamping out things like child pornography but anyone with half a brain knows that:
  1. Anyone wanting access to the sort of stuff this is intended to block will find a way around it. (This reminds me of when I was chatting to my wife's 14 yr old cousin who told me every kid in school knew how to use proxies to get around the school's content filter). More targeted strategies would have better success than a blanket approach like this that only harms the general populous (see point 3).
  2. Inevitably this sort of BS goes 1984 with the government allowed to block anything they want without public scrutiny (the list of blocked sites won't be made public). Think the great internet wall of China.
  3. The costs (a big slow-down in speeds, mistaken blockings etc) would be for nothing.
For more details, see:
  1. a recent article ...
  2. some great commentary ...
  3. and for how to sign a petition on this, see GetUp's campaign below:

Thursday, March 12, 2009


No, I'm not talking about redundancy in the information sense, but in terms of employment. On Monday I was made redundant from my part-time job, along with a number of other staff members there.

This kind of thing happens from time to time: I think almost everyone in the company had been made redundant from some previous job. Indeed, it's the second time for me after Telstra closed their research laboratories (see 1 and 2) three years ago.

A few things I just want to mention.
Firstly, the law around redundancy entitlements has changed, thanks to our our previous prime minister John Howard, friend of the worker. No severance payments are necessary anymore, just your 1 month's notice and good luck. In this market, you're going to be lucky to get a new job within 1 month - that's what a redundancy payment was designed for.
Also, I was asked to keep working through my notice period with the prospect of continuing on contract once the period ended. Obviously this is good, but without anything in writing I'm a bit concerned that we'll get to the end of the month and there won't be a contract. I'm sure a lot of others have had this dilemma over the years.

All that being said, I know that in the long run I am a very lucky guy, and things here could definitely be worse ...

(Update: the contract did come through before the notice period ended, and I'm still happily working there. Hopefully things pick up, as we're working on some really promising services.)

Wednesday, January 14, 2009

Happy New Year

2008 is no more.
It was very much a mixed year, with some great highs and some rather upsetting lows. But that's life.
A few people have told me that felt the same way about 2008; which is interesting. Perhaps there was something in the stars :).

Highlights included some great holidays: a trip to Port Douglas for my 30th, a weekend in the Hunter Valley with friends, what is becoming an almost annual trip to Europe (this year mainly around France, plus a little of Italy, Germany and the UK), and a couple of days at Terrigal across new year's.

On the PhD front, I had the first journal article from my PhD published, and I was really pleased that it was in a good physics journal (PRE). I also had 2 conference papers at ALifeXI in Winchester, another conference paper that I was a minor author on, and the year ends with 2 other journal articles submitted. ALifeXI was a great experience itself, as was GSO-2008 (see previous post), and I enjoyed lab visits at The University of Hertfordshire (UK) and The Bernstein Center for Computational Neuroscience (in Berlin). Unfortunately though, a significant amount of my experimental work went nowhere this year, particularly in the second half, which has been quite frustrating. That's the nature of research though: if everything turned out the way you thought/hoped, it would be engineering rather than science.

I enjoyed my part-time engineering job this year, feeling like I made a solid contribution to the team. It was nice to have a large role in our latest client implementation. For most of the year I was doing 2 days/week, but just before Christmas they've accomodated my request to drop down to one day/week. This will allow me to focus properly on my studies and get a decent night's sleep!

On the home front, our renovation work has mostly ground to a halt, although we did undertake one major project: the front garden. There are a couple of items still to complete, but I'm really happy with the results. I also finally built a myth-tv box (a home-brewed hard drive recorder), which was quite satisying from a geek perspective.
Turning 30 wasn't as challenging as I thought it would be, helped by two great parties my wife organised for me.
Speaking of whom, late in the year she was accepted to start her doctorate this year (in Education at The University of Technology, Sydney), which was really exciting. I know she's going to love the experience, and make an excellent contribution to her field.

The downsides were mainly health related.
I broke my ankle the night I arrived home from ALifeXI in August. It was the first time I've broken anything, and to be honest I didn't cope very well (mentally) for the first few weeks on crutches. But I had an awesome physio (Rick Reeve at West Ryde) who was really on the ball, and made a big difference to my mental health as well as physical. It was as simple as a break can be, but a break is a break and some 5 months later it's still not quite back to normal.
There were a couple of other health issues for us, which I don't want to go into here right now, and these really threw us on a number of occasions. For the moment, things seem to be back on track, but only time will tell.
There were some serious health issues for friends and family as well, including cancer, and the outcome there remains uncertain.
If all of this has taught me anything, it's the importance of staying positive.

Finally, it's been a tough year for our families. My in-laws bought a country pub, and it's been a lot of hard work for them settling into it. My parents started the year facing a few challenges, but things seem to be stable now, and importantly they seem happy.

What does 2009 hold? There's only one way to find out ... bring it on.