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Professor David Avis

Department of Communications and Computer Engineering
School of Informatics
Kyoto University
Yoshida-honmachi  36-1, Sakyo-ku,  Kyoto 606-8501, Japan
TEL: 075-753-5953
FAX: 075-753-5972

Email avis@i.kyoto-u.ac.jp
Office:  Engineering Building No. 10, room 342       access       map

 cv      short cv     Online publications 

 lrs Vertex Enumeration/Convex Hull package    Reverse search applications, implementations, tutorial, demo


School of Informatics International Courses           

  My courses:   Introduction to Algorithms and Informatics     Computational Intractability    Polyhedral Computation    

   Informatics Seminar

   Tohoku course

Geometric Computation Group

Geometric structures, especially high dimensional polyhedra, have become essential components of models in many areas of engineering and science. Applications arise in such diverse areas as bio-mechanics, chemistry, embedded systems, game theory, physics, robotics, scheduling and wireless networks. They are also at the heart of discrete optimization, particularly linear and integer programming. Related computational problems are computationally hard, and many important practical problems are currently out of reach with present technology. Our goal is to create new theoretical methods for geometric computation and to implement them in efficient, easily usable software for end-users. Research in this group is divided into three areas.

Research Topics

1. Polyhedral Computation.
We continue the development of the lrs library. This freely distributed and widely used code employs the reverse search technique and exact arithmetic to compute the vertices or faces of high dimensional polyhedra. New theoretical advances will be needed to improve its performance on the highly symmetric and degenerate combinatorial polytopes often found in practice.  We also work with current users of the software to develop additional features and new applications.

2. Discrete Optimization.
Problems in discrete optimization abound, with such well known examples as the travelling salesman problem, vehicle routing problems, scheduling problems, etc. The most promising general purpose approach to solving these kinds of problems is integer programming, and in particular, the branch-and-cut framework. Success with applying these methods often depends on a thorough study of the underlying polyhedral model using tools from polyhedral computation. We will look at specific new application areas for these techniques, as well as more fundamental questions on the complexity of the underlying computations.

3. Quantum Information.
The scale of future integrated circuity made the study of related quantum effects inevitable. As an exciting by-product the field of quantum information was born. This extends information theory to explore the additional communication power available by using quantum objects, such as entangled photons. Correlations between observations is at the very heart of this exciting area. Polyhedral models can completely describe correlations obtained by classical experiments, but quantum correlations require new geometric structures. We investigate the power of quantum information using tools from polyhedral computation and discrete optimization, especially semi-definite programming.


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