Most of the listed topics (but not all of them) can be tackled on all levels, as Honours, Masters or PhD projects. Please talk to me about details.
All projects listed below study self-organized systems and natural computation.
The paradigmatic example of self-organized groups are colonies of social insects, such as ants, termites, and (some species of) bees and wasps, whose strikingly organized and seemingly purposeful behavior at the group level is organized without any central "master plan". An ant colony's activities, such as coordinated attack when threatened or the building of complex trail networks, require elaborate coordination and decision making. Yet, despite the involvement of up to millions of individuals, there is no leader making the decisions: the complex behavior at the colony level emerges from simple interactions between myriads of individuals that only process local information.
Many aspects of self-organized phenomena in nature can be better understood from the viewpoint of information processing. Natural computation studies such phenomena as computational processes and uses information theory to explain their behavior.
Self-organized behavior exhibits a number of properties that are highly desirable in technical applications, specifically robustness, adaptiveness and parallelism. Hence, social insect behavior has been used as an inspiration for a wide range of engineering tasks. Among the most important examples of so-called "Swarm Intelligence" applications are ant colony optimization, a method for combinatorial optimization, swarm robotics and network routing.
We are specifically interested in the adaptiveness of self-organized systems, i.e. their ability to "reorganize" in order to adapt to a changing environment.
The projects offered come in two flavors: Some are theoretical and mainly concerned with understanding real biological systems, in particular ant colonies and slime molds. Others are technical and use the insights gained from the study of self-organizing systems to develop new solutions to computational problems.
All projects require a keen interest in inter-disciplinary work and an open mind. In the biological projects we are closely collaborating with the Behavior and Genetics of Social Insects Lab and the Center for Mathematical Biology at the School of Biological Sciences, University of Sydney. If you wish, you may have the opportunity in some projects to spend time in the lab, directly studying the behavior of real social insects. For most projects you will need skills in simulation (usually Java, Mathematica or Matlab) and for some you will also need advanced mathematical modelling (Dynamic Systems). I will warn you in these cases... Don't sign up for any of these projects without consulting me first!
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Ant colonies organize their foraging as well as other activities using indirect communication by laying pheromone trails (stygmergy) or using direct communication between individuals (invitation behavior). Mass recruitment by trail laying species has been widely studied (see, for example, this paper), is reasonably well understood, and has served has served as an inspiration for the solution of various computational problems (e.g. ant colony optimization). A excellent overview of this is given in Self-Organization in Biological Systems by Scott Camazine et al. (eds.) and in Information Processing in Social Insects by Claire Detrain et al. (eds.).
Recent studies suggest that recruitment by invitation behavior results in different properties on the colony level, potentially allowing the colony to adapt more quickly to changing environments. The project aims to understand (some of) the differences between these two forms of organization. We compare the two behaviors by performing parallel experiments with two different species in the lab (you can actively participate) and attempt to model the behavior with simulation models and/or analytic dynamic system models. |
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Recent studies have shown that ant colonies, somewhat counter-intuitively, use "noisy" communication to their advantage (paper). The studies suggest that noise allows self-organized systems generally, and ant colonies in particular, to adapt flexibly in changing environments. This can best be explained using an information-theoretic approach to quantify how quickly information about the environment spreads through a colony. We will study this phenomenon by developing simulations of known biological experiments that allow us to directly measure the information throughput. We will extend these simulations to predict results of yet-to-be-conducted experiments. |
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Recently it has been discovered that the True Slime Mold Physarum Polycephalum, an amoeba-like unicellular organism, is "smart enough" to solve the shortest path problem in mazes (news article). We are interested in whether slime molds can also flexibly adapt when the maze changes. We will explore this by building biologically realistic simulations of their behavior. |
A classical mathematical problem is the "Stable Marriage" (see also this survey paper). The challenge is a to find a pairing of a group of men and women into couples such that the overall stability (happiness?) of the group based on individual preferences for partners is in some sense optimized. We will attempt to solve this problem with a self-organizing algorithm, and we are specifically interested in the question whether this enables the group to reorganize optimally when new partners become available (or existing ones become unavailable). NB: This project is not sponsored by rsvp.com.au
The discovery that the True Slime Mold Physarum Polycephalum, an amoeba-like unicellular organism, can solve the shortest path problem in mazes (news article) has recently served as an inspiration for a new shortest path algorithm, termed Physarum Solver (paper). While this algorithm is theoretically interesting, its computational complexity limits its practical usefulness. Unlike other nature-inspired algorithms, such as Ant Colony Optimization or Genetic Algorithms, Physarum Solver does not use stochastic sampling to reduce the problem space. We will explore whether it is possible to extend Physarum Solver in this form and how this compares to other nature-inspired search methods.
FPGAs (Field-programmable gate arrays) are reconfigurable hardware circuits that can significantly speed up complex processing tasks. As they have to be specifically programmed for each task, the cost of configuration has to be balanced with the gain in processing speed. In a setting where different types of tasks arrive in an essentially unpredictable form, the reconfiguration management becomes a crucial component. Recently, a configuration algorithm based on the principles of task allocation in social insect colonies has been proposed (paper). Similar algorithms have previously already been used successfully for other optimization tasks, for example for paint booth scheduling in the car industry. We aim to better understand the performance of these algorithms for stochastic task arrivals using micro-simulation and, where appropriate, mathematical models.
The Causal Robotics Group and the Natural Computation Lab are building a swarm of micro robots that will eventually live in building 63. This is an open-ended long term project. Its aim is to experimentally explore self-organizing "intelligent" behaviour as we find it, for example, in ant colonies and swarms of bees. This is part of an ARC project investigating the principles of self-organized collective decision making, often somewhat more spectacularly termed Swarm Intelligence. The swarm will initially comprise about 20 micro robots that are customized from extensible off-the shelf units, specifically iRobots and/or ePucks. There is a variety of different honours projects available within this long-term initiative, including the development of control algorithms, simulations, and specialized sensor and actuator software/hardware. Talk to me about details if you are interested. You must be a competent programmer and in some cases an inclination to tinker with hardware, maybe even knowing how to use a soldering iron would help!