Particle swarm optimization (PSO) is a population based stochastic search and optimization process which was introduced in 1995 by Kennedy and Eberhart.  The natural behavior of a bird flock when searching for food is simulated through iterated movements of the individual particles or living organisms in the flock. The goal is to converge to the global optimum of some multi-dimensional fitness function.  Particle Swarm Optimization is conceptually related to other evolutionary algorithms such as Genetic Algorithms, Genetic Programming, Evolution Strategies, and Evolutionary Programming but differs from them in many aspects.

In this talk, we present two novel techniques, which extend the basic PSO algorithm.  The first algorithm called multi-dimensional PSO (M-D PSO) deals with problems in which the dimension of the solution space is not known a priori.  Recall that PSO and most evolutionary algorithms assume a fixed dimension.  Also, many model-based and filtering techniques assume a fixed model dimension or a filter order. M-D PSO solves such a problem by introducing two interleaved PSO iteration processes, a positional PSO (equivalent to the basic PSO operation) followed by a dimensional PSO in which the dimension of a particle is allowed to vary.  In a multi-dimensional search space where the optimum dimension is unknown, swarm particles can seek both positional and dimensional optima. 

Since the backbone of MD PSO is the basic PSO, it is still susceptible to premature convergence, especially at high dimensions.  To address this problem, we propose a second extension of the basic PSO algorithm, called Fractional Global Best Formation (FGBF) technique.  Instead of being guided by the best particle in the swarm (the member of the swarm that achieves the best value of the objective so far) a new particle is created whose j’th component is the best corresponding component of all particles in the whole swarm (i.e. a component-wise best particle).  The new particle is essentially a better guide to the swarm than PSO’s native global best, since it makes use of the larger diversity existing between the components of the swarm particles.  The presented techniques are applied in two well-known domains, nonlinear function minimization and data clustering.  An extensive set of experiments shows that in both application domains, MD PSO equipped with FGBF exhibits an impressive speed gain and converges to the global optima at the true dimension regardless of the search space dimension, swarm size and complexity of the problem.  In the second lecture, we will explore some of the following related extensions and applications:

Dr. MONCEF GABBOUJ received his BS degree in electrical engineering in 1985 from Oklahoma State University, Stillwater, and his MS and PhD degrees in electrical engineering from Purdue University, West Lafayette, Indiana, in 1986 and 1989, respectively.

Dr. Gabbouj is an Academy Professor and Professor at the Department of Signal Processing at Tampere University of Technology, Tampere, Finland.  He is currently a visiting scholar at the School of Electrical and Computer Engineering of Purdue University, West Lafayette, Indiana.  He was Head of the Department during 2002-2007.  Dr. Gabbouj was on sabbatical leave at the American University of Sharjah, UAE in 2007-2008. Dr. Gabbouj was Senior Research Fellow of the Academy of Finland during 2007-2008 and 1997-1998.  Dr. Gabbouj is the co-founder and past CEO of SuviSoft Oy Ltd.  From 1995 to 1998 he was a Professor with the Department of Information Technology of Pori School of Technology and Economics.  From 1994 to 1995 he was an Associate Professor with the Signal Processing Laboratory of Tampere University of Technology, Tampere, Finland.  From 1990 to 1993 he was a senior research scientist with the Research Institute for Information Technology, Tampere, Finland.  His research interests include multimedia content-based analysis, indexing and retrieval; nonlinear signal and image processing and analysis; and video processing, coding and communications.

Dr. Gabbouj is an IEEE Fellow.  He served as Distinguished Lecturer for the IEEE Circuits and Systems Society in 2004-2005, and Past-Chairman of the IEEE-EURASIP NSIP (Nonlinear Signal and Image Processing) Board.  He was chairman of the Algorithm Group of the EC COST 211quat.  He served as associate editor of the IEEE Transactions on Image Processing, and was guest editor of Multimedia Tools and Applications, the European journal Applied Signal Processing.  He is the past chairman of the IEEE Finland Section, the IEEE Circuits and Systems Society, Technical Committee on Digital Signal Processing, and the IEEE SP/CAS Finland Chapter.  He was also Chairman of CBMI 2005, WIAMIS 2001 and the TPC Chair of ISCCSP 2006 and 2004, CBMI 2003, EUSIPCO 2000, NORSIG 1996 and the DSP track chair of the 1996 IEEE ISCAS.  He is also member of EURASIP Advisory Board and past member of AdCom.  He also served as Publication Chair and Publicity Chair of IEEE ICIP 2005 and IEEE ICASSP 2006, respectively.  Dr. Gabbouj is a Honorary Guest Professor of Jilin University, China (2005-2010).

Dr. Gabbouj was the Director of the International University Programs in Information Technology (1991-2007) and vice member of the Council of the Department of Information Technology at Tampere University of Technology.  He is also the Vice-Director of the Academy of Finland Center of Excellence SPAG, Secretary of the International Advisory Board of Tampere International Center of Signal Processing, TICSP, and member of the Board of the Digital Media Institute.  He served as Tutoring Professor for Nokia Mobile Phones Leading Science Program (2005-2007 and 1998-2001).  He is a member of IEEE SP and CAS societies.

Dr. Gabbouj was the recipient of the 2005 Nokia Foundation Recognition Award and co-recipient of the Myril B. Reed Best Paper Award from the 32nd Midwest Symposium on Circuits and Systems and co-recipient of the NORSIG 94 Best Paper Award from the 1994 Nordic Signal Processing Symposium.  He is co-author of nearly 400 publications.

Dr. Gabbouj has been involved in several past and current EU Research and education projects and programs, including ESPRIT, HCM, IST, COST, Tempus and Erasmus.  He also served as Evaluator of IST proposals, and Auditor of a number of ACTS and IST projects on multimedia security, augmented and virtual reality, image and video signal processing.