Speaker: Manfred Opper (U Southampton) Title: Tractable Inference for Probabilistic Models Abstract: Probabilistic models (aka graphical models, Bayes belief networks) provide a powerful framework for modeling statistical dependencies between data. Their applications range from medical expert systems over encoders in telecommunication systems to spatial probabilistic models in meteorology. The price that a modeler has to pay for the high degree of flexibility of these models is the vast increase in computational complexity for adapting the models to data and for predicting unobserved causes (hidden nodes) from observations when the number of nodes in the network is large. Hence, the development of tractable but approximate inference techniques for Bayes networks is an important area of resarch. My talk will discuss ideas for approximate inference algorithms and their applications. Bio: Manfred Opper obtained a PhD in physics in 1987 in Giessen, Germany. After that he began to work on the application of statistical physics to the theory of neural networks. Following postdoctoral visits at the Ecole Normale Superieure in Paris (1989) and at the University of California at Santa Cruz (1990) he received the habilitation degree in theoretical physics in 1991. In 1992 he was awarded the Physics Prize of the German Physical Society for work on the dynamics of learning in neural networks. He was awarded a 3 year Heisenberg fellowship in 1994 enabling him to work at the machine learning group of UC Santa Cruz and at the Department of Complex systems of the Weizmann Institute in Israel. He joined the Neural Computing Research Group at Aston University as a Reader in 1997. In 2004 he moved to Southampton University where he is a reader at the ISIS research group. His research interests are in the cross connections between statistical physics, computational learning theory, information theory and mathematical statistics. He is currently working on the theory and applications of Gaussian processes and on the development of efficient inference techniques for complex probabilistic models.