Shape from Shading Revisited

When : Wednesday, November 16, 2005 - 16:00
Speaker : Prof. Jan Koenderink
Affiliation : Universiteit Utrecht, The Netherlands
Where : DEI - Aula Magna

Abstract :

'Shape from Shading' (SFS) has been extensively studied in machine
vision (first quantitative algorithms date from the 1950's in
astronomy). Shading has also been studied as an important visual cue,
and it is of considerable importance in the visual arts. It is
remarkable that the formal theories appear not to have the slightest
affinity to generally accepted artistic usage. Moreover the bulk of the
algorithms that have been proposed are particularly awkward candidates
for biological implementation. Moreover, it is not at all evident that
the 'SFS problem' as it is generally formulated has much relevance in
real life. One aspect that is particularly doubtful concerns the
observational basis for the calculations. I show that psychophysical
evidence suggests structures that fall neatly in line with artistic
praxis. I develop a formal apparatus for 'relative SFS', a method that
seeks to find the relief with respect to some fiducial (global) shape.
Such methods are also special because they manage with local
operations, whereas conventional SFS has to rely on global algorithms.
I also reconsider the observational basis and suggest that 'surface
illuminance flow' is an observable that complements 'shading' in
realistic settings.
Jan J. Koenderink graduated in Physics and Mathematics in 1967 at
Utrecht University. He has been associate professor in Experimental
Psychology at the Universiteit Groningen, then in 1974 returned to the
Universiteit Utrecht where he presently holds a chair in the Department
of Physics and Astronomy. He founded the Helmholtz Instituut in which
multidisciplinary work in biology, medicine, physics and computer
science is coordinated.
He has received an honorific degree (D.Sc.) in Medicine from the
University of Leuven and is a member of the Royal Netherlands Academy
of Arts and Sciences. He participates in the editorial boards of a
number of scientific journals, scientific boards of international
conferences and scientific institutes.
Research interests include cognitive science, ecological physics and
machine intelligence.

Precise Optical Measurement and Quantum Communication With Entangled Photons

When : Wednesday, June 1, 2005 - 17:00
Speaker : Prof. Alexander Sergienko
Affiliation : Boston University, Boston, USA
Where : DEI - AUla Magna

Abstract :

The power and high information capacity of entangled states has been so far demonstrated in several areas of quantum communication and quantum computing. We recently developed new techniques for precise optical measurement in life sciences and optoelectronics that take advantage of quantum entanglement and exceed traditional approaches both in resolution and in the amount of obtained information about the system under evaluation. We review our latest results in engineering special entangled-photon states with particular spectral, spatial, and polarization characteristics that enhance performance of quantum cryptography and such novel measurement technologies as quantum optical coherence tomography and quantum ellipsometry.
Alexander V. Sergienko (e-mail:; URL: received his M.S. and Ph.D. degrees in Physics from the Physics Department of Moscow State University in 1981 and 1987, respectively. After spending 1990-1991 academic year at the University of Maryland College Park as a Visiting Professor he joined the University of Maryland Baltimore County as a Research Assistant Professor in 1991. In 1996 Prof. Sergienko has joined the Faculty of the Department of Electrical and Computer Engineering at Boston University. Professor Sergienko is currently holding joint appointments in the Department of Electrical & Computer Engineering and in the Department of Physics. He is also a co-Director of the Quantum Imaging Laboratory at Boston University.


When : Tuesday, May 10, 2005 - 18:00
Speaker : Prof. Dr. Egon Balas
Affiliation : Carnegie Mellon University, Pittsburgh, PA
Where : DEI - AUla Magna

Abstract :

In the last 15 years the state of the art in mixed integer programming (MIP) has undergone a radical change. Known in the period 1960-1990 as a universal modeling tool which could be used to more or less accurately represent a variety of optimization problems from practically all areas of human activity, MIP was also known as a class of problems unsolvable in practice beyond prohibitively small instance sizes. The change occurred during the early 90's, and as a result today's leading commercial MIP codes are able to handle routinely most of the problems submitted to them. The jump in efficiency is due to a number of factors, like faster computers, faster and more reliable linear programming codes, etc.; but to a considerable extent, it is due to better cutting plane techniques and clever combinations of cutting planes with branch and bound. Ideas originating in the disjunctive programming approach during the 70's have led to the development of lift-and-project, a method for generating and analyzing cutting planes through a higher dimensional representation. This in turn has led to a reinterpretation and revival of the classical cutting planes of the early 60's. Starting with the late 90's, the leading commercial MIP codes contain cutting plane modules. First these were limited to the classical cuts, easiest to implement; but in 2003 one of these codes had its standard cut generating module replaced by a new one that produces lift-and-project cuts in the space of the original variables, leading to a further improvement in performance.


Egon Balas is University Professor of Industrial Administration and Applied Mathematics, as well as the Thomas Lord Professor of Operations Research, at Carnegie Mellon University. He has a doctorate in Economic Science from the University of Brussels and a doctorate in Mathematics from the University of Paris. Professor Balas research interests are in mathematical programming, primarily integer and combinatorial optimization. He has played a leading role in the development of enumerative and cutting plane techniques for 0-1 programming, and is mainly known as the developer of the approach called disjunctive programming or lift-and-project. He has also developed scheduling algorithms and software. Dr. Balas has served or is serving on the editorial boards of numerous professional journals. In 1980 Dr. Balas received the US Senior Scientist Award of the Alexander von Humboldt Foundation; in 1995 he received the John von Neumann Theory Prize of INFORMS; and in 2001 he was the first American to be awarded the EURO Gold Medal of the European Association of Operational Research Societies. In 2004 he was elected an outside member of the Hungarian Academy of Sciences. Professor Balas has published over 200 articles and scientific studies in the professional literature. He is also the author of the memoir Will to Freedom: A Perilous Journey Through Fascism and Communism. Syracuse University Press, 2000, also available in Hungarian, Romanian, French and Italian versions.

Scaling CMOS Technology to its Limits: A Physicist's Perspective

When : Thursday, March 17, 2005 - 15:30
Speaker : Prof. Massimo Fischetti
Affiliation : University of Amherst, USA
Where : Aula Magna DEI

New Frontiers in Optical Communications: MAN and Broadband Access

When : Wednesday, January 12, 2005 - 12:00
Speaker : Prof. Leonid Kazovsky
Affiliation : Stanford University, USA
Where : Aula Magna DEI

Abstract :


This talk will review where and why, in author's opinion, the most
interesting optical networking research will take place within the next
five to ten years.
First, we will briefly review research activities of the Stanford Photonics
and Networking Research Laboratory. Next, we will discuss the forces
driving deployment, research and development of next-generation optical
networks. Further, we will focus on two areas where most of the new action
will take place: metropolitan area networks and broadband access. Then, we
will discuss interconnection challenges. Lastly, we will look into the
question of key optical components that will be needed for future networks.


Prof. Leonid Kazovsky is a head of the Stanford Photonics and Networking
Research Laboratory which he founded in 1990. Prior to joining Stanford in
1990, Prof. Kazovsky was with Bellcore (now Telcordia). Prof. Kazovsky is
a Fellow of IEEE, Fellow of OSA, and serves on editorial boards of several
journals and conferences.