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Events for September 22, 2006
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The Physical View of Computational Complexity
Fri, Sep 22, 2006 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Dr. Allon Percus
Division of Computer, Computational and Statistical Sciences, LANL / Department of Mathematics, UCLAPhysicists define a phase transition as an abrupt change in microscopic order, such as the transition from a solid to a liquid. Many fundamental problems in computer science exhibit phase transitions as well. The classic example is satisfiability: given a set of logical constraints acting on Boolean variables, can one assign truth values to the variables so that all constraints are simultaneously satisfied? For randomly generated formulas with many variables, as one increases the number of constraints per variable, there is a threshold at which the answer goes abruptly from almost certainly yes to almost certainly no. Moreover, this phase transition is connected with algorithmic performance. Over a wide range of computational problems, the hardest instances to solve are those near the transition. I will discuss the role of phase transitions in random combinatorial problems,demonstrating how the physical view of the phase structure has transformed our understanding of average-case computational complexity and inspired new algorithmic approaches.Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Shane Goodoff
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Finite-Length Optimization of Iterative Coding Systems Via Scaling
Fri, Sep 22, 2006 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Prof. Ruediger Urbanke, Swiss Federal Institute of TechnologyABSTRACT: The infinite-length performance of iterative coding systems is by now relatively well understood. Much less is known about the practical important case of finite-length codes. I will argue that a method called "finite-length scaling", which is based on relating the code performance of various lengths, is a useful tool for the analysis and optimization of real systems. This method has the advantage that it is in principle applicable in a fairly general setting.So far, however, the method has been worked out explicitly only for the case of transmission over the binary erasure channel and we are just about to understand the case of transmission over the binary symmetric channel under Gallager A decoding.I will describe what remains to be done and what we can expect to see as final result.[This is joint work with Abdelaziz Amraoui, Jeremie Ezri, and Andrea Montanari.]Bio: Ruediger L. Urbanke received his Diplomingenieur from the Vienna Institute of Technology in 1990 and his M.S. and Ph.D. in Electrical Engineering from Washington University in 1992 and 1995, respectively. From 1995-1999 he held a position at the Mathematics of Communications Department at Bell Labs. Since November 1999, he has been on the Faculty of the Swiss Federal Institute of Technology in Lausanne. He is a recipient of a Fulbright Scholarship and a co-recipient of the IEEE Transactions on Information Theory 2002 Best Paper Award. Since October 2000 he has been an Associate Editor of the IEEE Transactions on Information Theory.Host: Prof. Giuseppe Caire, caire@usc.edu
Location: Vivian Hall of Engineering (VHE) - 217
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Chem-Bio Informatics Approaches to Drug Design by Dr. Rajni Garg
Fri, Sep 22, 2006 @ 01:00 PM - 02:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Computer assisted drug design techniques play a major role in lead optimization in drug discovery and development, which significantly reduces the time and cost. Chem.-bio informatics encompasses the design, organization, storage, management, retrieval, analysis, dissemination, visualization and use of chemical and biological information. Various tasks involved are data mining, molecular modeling (docking), defining quantitative structure-activity relationships (QSAR), pharmacophore mapping, structure/substructure searching etc. for predicting biological activity and other properties from chemical structure. Lately, many engineering approaches such as data mining, neural networks, pattern recognition, shape analysis and 3D graphics are being increasingly applied for multi-modality data analysis in order to understand the drug-receptor interaction. In the first part of the talk an introduction of QSAR, neural network, pharmacophore mapping and some of the molecular modeling techniques will be presented. The second half will focus on role of some of the emerging approaches in chem.-bio informatics and a few selected applications in HIV drug design and environmental toxicity will be presented.Bio:
Dr. Rajni Garg received the Ph.D. degree from Birla Institute of Technology and Science (BITS), Pilani, India in 1996. She joined Professor Corwin Hansch’s laboratory for her postdoctoral research in 1997. She is now a Research Professor in Chemistry and Bimolecular Science Department at Clarkson University, NY; and chemistry and Biochemistry Department at Cal State, San Marcos, CA. Her research interests are in the areas of computer-aided drug design, database development, data mining, chembioinformatics, and environmental toxicity prediction. Dr. Garg is a member of ACS, ISCB, AAAS and many other Societies. She received ACS Cycle of Excellence Award for most accessed article in Chem. Rev. in 2004. Currently, Dr. Garg is advising 3 graduate students research at Clarkson University (see website www.clarkson.edu/~rgarg). Students in her lab have received prestigious CCG Excellence Graduate Award (230th ACS National Meeting, 2005), Shipley Teaching Assistantship award (2005-2006), and CINF- Graduate Fellowship (231st ACS National Meeting, 2006) and summer internships in Pfizer, Wyeth etc. Dr. Garg is a co-author of 32 technical publications in international journals. She has presented her research in 37 national and international conferences as well as contributed two book chapters. Dr. Garg serves as expert reviewer for articles submitted in Mini-Reviews in Medicinal Chemistry, Current Medicinal Chemistry, Bioorganic Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters, Internet Electronic Journal of Molecular Design and Letters in Drug Design and Discovery.Host: Professor CC Jay Kuo, x04658, cckuo@sipi.usc.eduLocation: Grace Ford Salvatori Hall Of Letters, Arts & Sciences (GFS) - 116
Audiences: Everyone Is Invited
Contact: Gloria Halfacre
