oliver.obst.eu

The Third International Workshop on Guided Self-Organisation (GSO-2010) will be held at Indiana University in Bloomington, Indiana, USA, 4-6 September 2010.

The workshop is comprised of a group of researchers with diverse yet related interests, overlapping in the area of self-organizing systems and methods for characterizing those systems in ways that may ultimately allow them to be guided toward prespecified goals. Information theory and graph theory are core to many of these methods; quantifying complexity and its sources a common theme.

If interested in participating, send an extended abstract to the email addresses on the workshop web site.  Selected works from the workshop will likely be published in a special journal issue (as has been the case in the past).  More information on the GSO-2010 web site.

guided self-organisation, workshop, artificial life, ai

You are invited to submit to and/or attend The First Australasian Workshop on Computation in Cyber-Physical Systems (CompCPS-2010).
We are organising this event here in Sydney, on the 15-16 July, in the Lecture Theatre at the CSIRO Marsfield site.

The name “cyber-physical system” (CPS) was chosen by the NSF and other United States federal agencies for systems that coherently combine computational and physical elements.

The CPS field builds up on knowledge and practical experiences of embedded systems, sensor networks, multi-robot teams, modular/swarm robotics, amorphous computing, programmable materials, evolvable/adaptive hardware, etc., and yet promise to form a unique field.

This Workshop will focus on distributed computation in CPS – the computation processes that integrate multiple data streams, compress and structure high-dimensional information, synchronise the distributed dynamics, adapt to topological changes within networks, optimise multiple sensorimotor loops, etc.

Several prominent invited speakers from Australia, Spain and USA will present different aspects of this rapidly developing research field.

Anyone interested in participating in the workshop is encouraged to submit a two-page extended abstract by May 16, 2010. Notifications will be sent by June 11, 2010 to all those who will be invited to the workshop. All accepted submissions will be allocated an oral presentation slot. See the Workshop Web Page for details.

cyber-physical systems, workshop, australia, call for papers, Sydney, australasia, sensor networks

To get a quick overview on what is happening this year at NIPS, I have taken the titles of accepted papers and used the resulting text to produce a word cloud (a screen shot created using http://www.wordle.net/). The word cloud shows the hottest topics as the largest words (unsurprisingly, ‘learning’ is the most prominent word in all the titles). But see for yourselves…

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Our new paper describes a mathematical model for generic neural microcircuits, with potential engineering applications, as well as implications to understand how networks in biology are shaped to be optimally adapted to requirements of their environment.

Reservoir computing (RC) is a recent paradigm in the field of recurrent neural networks. Networks in RC have a sparsely and randomly connected fixed hidden layer, and only output connections are trained. RC networks have recently received increased attention as a mathematical model for generic neural microcircuits to investigate and explain computations in neocortical columns. Applied to specific tasks, their fixed random connectivity, however, leads to significant variation in performance. Few problem-specific optimization procedures are known, which would be important for engineering applications, but also in order to understand how networks in biology are shaped to be optimally adapted to requirements of their environment. We study a general network initialization method using permutation matrices and derive a new unsupervised learning rule based on intrinsic plasticity (IP). The IP-based learning uses only local learning, and its aim is to improve network performance in a self-organized way. Using three different benchmarks, we show that networks with permutation matrices for the reservoir connectivity have much more persistent memory than the other methods but are also able to perform highly nonlinear mappings. We also show that IP-based on sigmoid transfer functions is limited concerning the output distributions that can be achieved.

neurophysiology, optimisation, physiological models, recurrent neural nets, unsupervised learning, reservoir computing, echo state networks

The principle of least effort in communications has been shown, by Ferrer i Cancho and Solé, to explain emergence of power laws (e.g., Zipf’s law) in human languages. In our new paper, Origins of Scaling in Genetic Code (O. Obst, D. Polani, M. Prokopenko), published on ECAL 2009, we  apply the principle and the information-theoretic model of Ferrer i Cancho and Solé to genetic coding. The application of the principle is achieved via equating the ambiguity of signals used by “speakers” with codon usage, on the one hand, and the effort of “hearers” with needs of amino acid translation mechanics, on the other hand. The re-interpreted model captures the case of the typical (vertical) gene transfer, and confirms that Zipf’s law can be found in the transition between referentially useless systems (i.e., ambiguous genetic coding) and indexical reference systems (i.e., zero-redundancy genetic coding). As with linguistic symbols, arranging genetic codes according to Zipf’s law is observed to be the optimal solution for maximising the referential power under the effort constraints. Thus, the model identifies the origins of scaling in genetic coding — via a trade-off between codon usage and needs of amino acid translation. Furthermore, the paper extends Ferrer i Cancho ­ Solé model to multiple inputs, reaching out toward the case of horizontal gene transfer (HGT) where multiple contributors may share the same genetic coding. Importantly, the extended model also leads to a sharp transition between referentially useless systems (ambiguous HGT) and indexical reference systems (zero-redundancy HGT). Zipf’s law is also observed to be the optimal solution in the HGT case.

genetic code, evolution, language, zipf’s law, horizontal gene transfer

I was excited to find one of my approaches being used in a commercial product for emergency egress simulation, sold by a company in the US: Back in 2006, Heni, Jan and I published an approach we called Inverse Steering Behaviors in the chapter “Fast, Neat, and Under Control: Arbitrating Between Steering Behaviors” of AI Game Programming Wisdom 3. The technique builds on Steering Behaviors by Craig Reynolds – reactive procedures for physical agents (like robots or simulated creatures) to move in a lifelike way within dynamic environments. Developed in the late 80s, steering behaviors found applications for example in movies like Lord of the Rings. Our Inverse Steering Behaviors improve the arbitration between individual behaviors, which results in less collisions. Back when we did the work, we used the approach in our robotic soccer team for navigation and to dribble around opponents. The agent-based emergency evacuation simulation system sold by  Thunderhead Engineering, is called Pathfinder.
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In a paper that was recently accepted at the European Symposium on Artificial Neural Networks (ESANN 2009), we look at different ways to influence the performance of echo state networks. Traditionally, echo state networks and other reservoir computing approaches use a fixed random connected reservoir, which leads to significant variation in performance. Only few problem specific optimisation procedures are known to date. We study a general initialization method using permutation matrices and derive a new unsupervised learning rule based on intrinsic plasticity (IP) for echo state networks. Using three different benchmarks, we show that networks with permutation matrices for the reservoir connectivity have much longer memory than the other methods, but are also able to perform highly non-linear mappings. We also show that IP based on sigmoid transfer functions is limited concerning the output distributions that can be achieved.

Studies on Reservoir Initialization and Dynamics Shaping in Echo State Networks,
J. Boedecker, O. Obst, N.M. Mayer, M. Asada. The full paper will be available after the conference (April) is now available.

neural networks, intrinsic plasticity, echo state networks, reservoir computing

ICDL is a multidisciplinary conference pertaining to all subjects related to
the development and learning processes of natural and artificial systems,
including perceptual, cognitive, behavioral, emotional and all other mental
capabilities that are exhibited by humans, higher animals, and robots. Its
visionary goal is to understand autonomous development in humans and higher
animals in biological, functional, and computational terms, and to enable such
development in artificial systems. ICDL strives to bring together researchers
in neuroscience, psychology, artificial intelligence, robotics and other
related areas to encourage understanding and cross-fertilization of latest
ideas. ICDL2009 is held in Shanghai, June 5-7, 2009.
For a list of topics of see the CfP at http://www.icdl09.org/.

icdl, conference, cfp, learning, development, robotics

Finally, the book Computers in Sport (edited by P. Dabnicki and A. Baca) appeared. In this book, my colleagues and I have a chapter “Approaching a Formal Soccer Theory from the Behavior Specification in Robotic Soccer“, where we discuss a top-down approach to modelling soccer knowledge, as it can be found in soccer theory books. The goal is to model soccer strategies and tactics in a way that they are usable for multiple robotic soccer leagues in the RoboCup. We investigate if and how soccer theory can be formalized such that specification and execution are possible. The advantage is clear: theory abstracts from hardware and from specific situations in different leagues. We introduce basic primitives compliant with the terminology known in soccer theory, discuss an example on an abstract level and formalize it. The formalization of soccer presented here is appealing. It goes beyond the behaviour specification of soccer playing robots. For sports science a unified formal soccer theory might help to better understand and to formulate basic concepts in soccer. The possibility of the formalization to develop computer programs, which allow to simulate and to reason about soccer moves, might also take sports science a step further.
Get your copy of the book at your local book shop or at Amazon .

Technorati Tags: book, sport, computers, robocup, robots, theory

The Idiap research institute (http://www.idiap.ch) seeks several PhD
students in the field of brain-computer interfaces (BCI) to work in the
team of Prof. José del R. Millán (http://people.epfl.ch/jose.millan).

The doctoral student will work in the framework of European and Swiss
projects related to the development of noninvasive brain-actuated
devices in areas ranging from communication to neuroprostheses, and from
interaction to rehabilitation. Projects aim at developing practical BCI
technology, but will also investigate basic questions such as online
adaptation, cognitive processes, multimodal signal fusion, and
brain-robot interaction.

Interested candidates should apply through the Idiap online recruitment
system http://jobs.idiap.ch and send the requested material.

Technorati Tags: job, phd, positions, robotics, brain-computer interfaces, bci, europe