Peter Lichodzijewski, Ph. D.

Dalhousie University
Halifax, Nova Scotia

plichodz [at symbol] dal [period] ca



Research Interests

I'm interested in using Evolutionary Computation (EC) for model building -- how to use concepts such as populations, genetic variation, and natural selection to automatically build solutions to a given problem. My work has dealt mainly with Genetic Programming (GP), a branch of EC where the solutions take the form of (relatively) simple programs (e.g., arithmetic expressions).

GP, and in general EC, can be used to find novel solutions to some interesting and difficult problems (see the HUMIES page). Two domains that I have experience with are classification and reinforcement learning. Classification deals with the categorization of data, while the goal of reinforcement learning is to learn useful policies through interaction with an environment.

My current work looks at the issues of scalability and solution transparency.  A learning algorithm is viewed as scalable if it can be successfully applied to very large problems (in terms of the number of training instances or environmental states). Solution transparency is important as it allows an end-user to gain insight into the problem by analyzing the models that are developed. My work investigates the usefulness of competitive coevolution in overcoming the issue of scalability, while solution transparency is addressed through bid-based problem decomposition. As it turns out, the latter also provides an elegant way of building solutions that are structured hierarchically which further supports the goal of scalability (though perhaps, but not necessarily, at the expense of solution transparency).

In early 2011, I defended my doctoral thesis "A Symbiotic Bid-Based Framework for Problem Decomposition using Genetic Programming" which delves into these ideas in detail. In the near future I plan to release the associated source code, which for now can obtained by contacting me by email.



Journal Publications
  1. Doucette, J., McIntyre, A., Lichodzijewski, P., Heywood, M.I., "Symbiotic Coevolutionary Genetic Programming: A Benchmarking Study under Large Attribute Spaces," Genetic Programming and Evolvable Machines, Vol. 13, No. 1, pp. 71-101, March 2012. (more)

  2. Lichodzijewski, P., Heywood, M.I., "Coevolutionary Bid-Based Genetic Programming for Problem Decomposition in Classification," Genetic Programming and Evolvable Machines, Vol. 9, No. 4, pp. 331-365, December 2008. (more)

  3. Curry, R., Lichodzijewski, P., Heywood, M.I., "Scaling Genetic Programming to Large Datasets using Hierarchical Dynamic Subset Selection," IEEE Transactions on Systems, Man, and Cybernetics - Part B: Cybernetics, Vol. 37, No. 4, pp. 1065-1073, August 2007. (more)

Book Chapters

  1. Lichodzijewski, P., Heywood, M.I., "The Rubik's Cube and GP Temporal Sequence Learning: An Initial Study," Genetic Programming Theory and Practice, Vol 8., Ch. 3, pp. 35-54, 2011. (more)

  2. Doucette, J., Lichodzijewski, P., Heywood, M.I., "Evolving Coevolutionary Classifiers under Large Attribute Spaces," Genetic Programming Theory and Practice, Vol. 7, Ch. 3, pp. 37-54, 2010. (more)

Conference Publications

  1. Doucette, J., Lichodzijewski, P., Heywood, M.I., "Hierarchical Task Decomposition through Symbiosis in Reinforcement Learning," Proceedings of the 2012 Genetic and Evolutionary Computation Conference, July 2012. (to appear)

  2. Kelly, S., Lichodzijewski, P., Heywood, M.I., "On Meta Actions and Hierarchical Symbiosis," Proceedings of the IEEE Congress on Evolutionary Computation, 2012. (to appear)

  3. Lichodzijewski, P., Heywood, M.I., "Symbiosis, Complexification and Simplicity under GP," Proceedings of the 2010 Genetic and Evolutionary Computation Conference, July 2010. (more)

  4. Heywood, M.I., Lichodzijewski, P., "Symbiogenesis as a Mechanism for Building Complex Adaptive Systems: A Review," Proceedings of the European Workshop on Evolutionary Algorithms and Complex Systems, April 2010. (more)

  5. Lichodzijewski, P., Heywood, M.I., "Binary versus Real-Valued Reward Functions under Coevolutionary Reinforcement Learning," Proceedings of the 9th International Conference on Artificial Evolution, October 2009.

  6. Alshammari, R., Lichodzijewski, P., Heywood, M.I., Zincir-Heywood, A. N., "Classifying SSH Encrypted Traffic with Minimum Packet Header Features using Genetic Programming," Proceedings of the 2009 Genetic and Evolutionary Computation Conference, pp. 2539-2546, July 2009. (more)

  7. Doucette, J., Lichodzijewski, P., Heywood, M.I., "Benchmarking Coevolutionary Teaming under Classification Problems with Large Attribute Spaces," Proceedings of the 2009 Genetic and Evolutionary Computation Conference, pp. 1901-1902, July 2009. (more)

  8. Lichodzijewski, P., Heywood, M.I., "Managing Team-Based Problem Solving with Symbiotic Bid-Based Genetic Programming," Proceedings of the 2008 Genetic and Evolutionary Computation Conference, pp. 363-370, July 2008. (more)

  9. Lichodzijewski, P., Heywood, M.I., "Pareto-Coevolutionary Genetic Programming for Problem Decomposition in Multi-Class Classification," Proceedings of the 2007 Genetic and Evolutionary Computation Conference, pp. 464-471, July 2007. (more)

  10. Lichodzijewski, P., Heywood, M.I., "GP Classifier Problem Decomposition Using First-Price and Second-Price Auctions," Proceedings of the 10th European Conference on Genetic Programming, pp. 137-147, April 2007. (more)

  11. Allulli, L., Lichodzijewski, P., Zeh, N., "A Faster Cache-Oblivious Shortest-Path Algorithm for Undirected Graphs with Bounded Edge Lengths," Proceedings of the 18th ACM-SIAM Symposium on Discrete Algorithms, pp. 910-919, January 2007.  (more)

  12. Wang, S., Lichodzijewski, P., "Boolean Genetic Programming for Promoter Recognition in Eukaryotes," Proceedings of the IEEE Congress on Evolutionary Computation, Vol. 1, pp. 683-690, September 2005. (more)

  13. Lichodzijewski, P., Heywood, M.I., Zincir-Heywood, A.N., "CasGP: Building Cascaded Hierarchical Models Using Niching," Proceedings of the IEEE Congress on Evolutionary Computation, Vol. 2, pp. 1180-1187, September 2005. (more)

  14. Lichodzijewski, P., Heywood, M.I., Zincir-Heywood, A.N., "Cascaded GP Models for Data Mining," Proceedings of the IEEE Congress on Evolutionary Computation, Vol. 2, pp. 2258-2264, July 2004. (more)

  15. Lichodzijewski, P., Wetmore L., Zincir-Heywood, A.N., "Pie: Scalable Routing in Peer-to-Peer Networks," Proceedings of the IEEE Canadian Conference on Electrical and Computer Engineering, Vol. 1, pp. 51-54, May 2004. (more)

  16. Lichodzijewski, P., Zincir-Heywood, A.N., Heywood, M.I., "Dynamic Intrusion Detection Using Self-Organizing Maps," Proceedings of the 14th Annual Canadian Information Technology Security Symposium, May 2002.

  17. Lichodzijewski, P., Zincir-Heywood, A.N., Heywood, M.I., "Host-Based Intrusion Detection Using Self-Organizing Feature Maps," Proceedings of the IEEE International Joint Conference on Neural Networks, Vol. 2, pp. 1714-1719, May 2002. (more)

Theses
  1. Lichodzijewski, P., "A Symbiotic Bid-Based Framework for Problem Decomposition using Genetic Programming," Ph.D. Thesis, Faculty of Computer Science, Dalhousie University, February 2011. (more)

  2. Lichodzijewski, P., "Cascaded GP Models for Data Mining," Master's Thesis, Faculty of Computer Science, Dalhousie University, August 2004.

  3. Lichodzijewski, P., "Network-Based Anomaly Detection Using Self-Organizing Maps", Honours Thesis, Faculty of Computer Science, Dalhousie University, April 2002.