Institute for Mathematics and its Applications University of Minnesota 400 Lind Hall 207 Church Street SE Minneapolis, MN 55455 
20042005 Program
See http://www.ima.umn.edu/matter for a full description of the
20042005 program on
Mathematics of Materials and Macromolecules: Multiple Scales, Disorder, and Singularities
and http://www.ima.umn.edu/schedule for schedule updates.
Topics to be covered in lectures, discussion, and poster sessions include pattern formation, coarsegraining in statistical physics, epitaxial growth, atomic to continuum models, and complex fluids.
The PI summer graduate program, which is open only to graduate students from IMA Participating Institutions, is currently full.
The aim of the program is to bring together some of the leading researchers to present stateoftheart results as well as to identify open problems and future directions. One feature of the program is that it will focus on the deeper issue of studying the interplay of the physical, link, and network layers in wireless networks. It will emphasize therefore involve stochastic calculus, information theory, signal processing, optimization, and control theory. Our objective is to facilitate the communications between academia and the industry, and to bridge the mathematical sciences, engineering, and operations research communities.
The program will consist of a 3day tutorial, which precedes a 5day workshop. The tutorial is aimed especially at young researchers new to this area, will provide background knowledge for the workshop, and entry to this active research area. Topics of the workshop include: control and optimization approach to wireless networks, network planning and optimization, air interface scheduling, multihop networks, coding theory for highspeed data over wireless, performance measurement of wireless data networks, information theory of multiple antennas, wireless channel prediction.
11:15a12:15p  From discrete to continuum systems: Crystallization in two dimensions  Florian Theil University of Warwick  Lind Hall 409  MS 
All Day  Chair: Mitchell Luskin  EE/CS 3180  W6.811.05  
8:30a9:15a  Coffee and Registration  EE/CS 3176  W6.811.05  
9:15a9:30a  Welcome and Introduction  Douglas N. Arnold University of Minnesota  EE/CS 3180  W6.811.05 
9:30a10:30a  Estimating systematic errors: sloppy models  James P. Sethna Cornell University  EE/CS 3180  W6.811.05 
10:30a11:30a  Coffee  EE/CS 3176  W6.811.05  
11:00a12:00p  Inserting computational chemistry in materials science: a guided tour  Claude Le Bris CERMICS  EE/CS 3180  W6.811.05 
12:00p2:30p  Lunch Break  W6.811.05  
2:30p3:30p  Boundary conditions for molecular dynamics  Xiantao Li University of Minnesota  EE/CS 3180  W6.811.05 
3:45p4:45p  IMA Tea and more (with POSTER SESSION)  Lind Hall 400  W6.811.05  
A mechanical model of the teleost fin ray  Silas Alben New York University  Courant Institute  
Higher order gradient continuum description of atomistic models for crystalline solids  Marcel Arndt University of Bonn  
A stochastic immersed boundary method for biological fluid dynamics at microscopic length scales  Paul Atzberger Rensselaer Polytechnic Institute  
A nonlinear membrane model by means of Young measures  Marian Bocea University of Utah  
Microtwists & Nanodefects  Antonio Di Carlo Universita` degli Studi Roma Tre  
A direct approach to numerical homogenization in finite elasticity  Antoine Gloria CERMICS  ENPC  
On the use of topological indices in quantitative structureproperty relationships for macromolecules  Kevin W. Mclaughlin University of Wisconsin  River Falls  
General nonlinear hydrodynamic description of nonNewtonian fluids  Harald Pleiner Max Planck Institute for Polymer Research  
Slip boundary condition for the moving contact line in immiscible twophase flows  Tiezheng Qian Hong Kong University of Science and Technology  
Anchoring distortions coupled with plane Couette and Poiseuille flows of nematic polymers  Hong Zhou Naval Postgraduate School  
Nonaffine deformations of networks of semiflexible polymers  Erik van der Giessen University of Groningen 
All Day  Chair: Robert V. Kohn  EE/CS 3180  W6.811.05  
9:00a9:30a  Coffee  EE/CS 3176  W6.811.05  
9:30a10:30a  Thermodynamic framework for systematic coarsegraining of atomistic models for fluids  Hans Christian Oettinger ETHZ  EE/CS 3180  W6.811.05 
10:30a11:30a  Coffee  EE/CS 3176  W6.811.05  
11:00a12:00p  A paradigm of kinetic theories for suspensions and nematic polymers  Qi Wang Florida State University  EE/CS 3180  W6.811.05 
12:00p2:30p  Lunch Break  W6.811.05  
2:30p3:30p  Systematic coarsegraining and concurrent multiresolution simulation of molecular liquids  Cameron F. Abrams Drexel University  EE/CS 3180  W6.811.05 
3:30p3:45p  Coffee  W6.811.05  
3:45p4:45p  Dislocation field theory in 2D: formulation and validation  Erik van der Giessen University of Groningen  EE/CS 3180  W6.811.05 
All Day  Chair: Richard D. James  EE/CS 3180  W6.811.05  
9:00a9:30a  Coffee  EE/CS 3176  W6.811.05  
9:30a10:30a  Continuum approach to crystal surface morphology evolution  Dionisios Margetis Massachusetts Institute of Technology  EE/CS 3180  W6.811.05 
10:30a11:00a  Coffee  EE/CS 3176  W6.811.05  
11:00a12:00p  Selfassembly and shape transitions of epitaxial nanowires and strained monolayer islands  Vivek Shenoy Brown University  EE/CS 3180  W6.811.05 
12:00p2:30p  Lunch Break  W6.811.05  
2:30p3:30p  Computations of strained heteroepitaxy in 3 dimensions using kinetic Monte Carlo  Peter Smereka University of Michigan  EE/CS 3180  W6.811.05 
3:30p3:45p  Coffee  EE/CS 3176  W6.811.05  
3:45p4:45p  The effect of screening and correlations in Ostwald ripening  Barbara Niethammer Humboldt Universität zu Berlin  EE/CS 3180  W6.811.05 
All Day  Chair: Claude Le Bris  EE/CS 3180  W6.811.05  
9:00a9:30a  Coffee  EE/CS 3176  W6.811.05  
9:30a10:30a  Slip boundary condition for the moving contact line in immiscible twophase flows  Tiezheng Qian Hong Kong University of Science and Technology  EE/CS 3180  W6.811.05 
10:30a11:00a  Coffee  EE/CS 3176  W6.811.05  
11:00a12:00p  Multiscale modeling of contact line dynamics  Weiqing Ren Princeton University  EE/CS 3180  W6.811.05 
12:00p2:30p  Lunch Break  W6.811.05  
2:30p3:30p  Simple lattice systems with complex macroscopic description  Andrea Braides II Universita degli studi di Rome (Tor Vergata)  EE/CS 3180  W6.811.05 
1:00p1:15p  Welcome  Douglas N. Arnold University of Minnesota Philip Fleming Motorola, Inc.  EE/CS 3180  SP6.227.1.05 
1:15p1:45p  Overview  Philip Fleming Motorola, Inc.  EE/CS 3180  SP6.227.1.05 
1:45p2:00p  Break  EE/CS 3176  SP6.227.1.05  
2:00p3:00p  Entropy, inference, and channel capacity  Sean P. Meyn University of Illinois  UrbanaChampaign  EE/CS 3180  SP6.227.1.05 
3:00p3:30p  Break  EE/CS 3176  SP6.227.1.05  
3:30p4:30p  System analysis of wireless packet networks carrying voice over IP  Philip Fleming Motorola, Inc.  EE/CS 3180  SP6.227.1.05 
4:30p5:00p  Break  EE/CS 3176  SP6.227.1.05  
5:00p6:00p  Scheduling and resource management in 3G, Wimax and allIP wireless networks  Thierry Klein Lucent Technologies 
EE/CS 3180  SP6.227.1.05 
7:00p8:00p  Dinner  Location: TBA  SP6.227.1.05 
8:30a9:00a  coffee and rolls  EE/CS 3176  SP6.227.1.05  
9:00a10:30a  Capacity, architecture, and protocols for ad hoc wireless networks  P. R. Kumar University of Illinois  UrbanaChampaign  EE/CS 3180  SP6.227.1.05 
10:30a11:00a  Break  EE/CS 3180  SP6.227.1.05  
11:00a12:30p  Capacity, architecture, and protocols for ad hoc wireless networks  P. R. Kumar University of Illinois  UrbanaChampaign  EE/CS 3180  SP6.227.1.05 
12:30p2:00p  Lunch  SP6.227.1.05  
2:00p3:00p  Entropy, inference, and channel capacity  Sean P. Meyn University of Illinois  UrbanaChampaign  EE/CS 3180  SP6.227.1.05 
3:00p3:30p  Break  EE/CS 3176  SP6.227.1.05  
3:30p4:30p  Scheduling and resource management in 3G, Wimax and allIP wireless networks  Thierry Klein Lucent Technologies 
EE/CS 3180  SP6.227.1.05 
5:00p6:00p  Reception  EE/CS 3176  SP6.227.1.05 
8:00a8:30a  coffee and rolls  EE/CS 3176  SP6.227.1.05  
8:30a10:00a  System analysis of wireless packet networks carrying voice over IP  Philip Fleming Motorola, Inc.  EE/CS 3180  SP6.227.1.05 
10:00a10:30a  Break  EE/CS 3176  SP6.227.1.05  
10:30a11:30a  Entropy, inference, and channel capacity  Sean P. Meyn University of Illinois  UrbanaChampaign  EE/CS 3180  SP6.227.1.05 
11:30a1:00p  Lunch  SP6.227.1.05  
1:00p2:30p  Scheduling and resource management in 3G, Wimax and allIP wireless networks  Thierry Klein Lucent Technologies 
EE/CS 3180  SP6.227.1.05 
2:30p3:00p  Wrapup  Douglas N. Arnold University of Minnesota Philip Fleming Motorola, Inc.  EE/CS 3180  SP6.227.1.05 
8:30a9:15a  Coffee  EE/CS 3176  SP6.227.1.05  
9:15a9:30a  Opening:  Douglas N. Arnold University of Minnesota  EE/CS 3180  SP6.227.1.05 
9:30a10:30a  Cross layer optimization in wireless networks  Francois Baccelli Ecole Normale Superieure  EE/CS 3180  SP6.227.1.05 
10:30a11:00a  Coffee  EE/CS 3176  SP6.227.1.05  
11:00a12:00p  Flowlevel performance in wireless data networks  Sem C. Borst Lucent Technologies  Bell Laboratories  EE/CS 3180  SP6.227.1.05 
12:00p2:00p  Lunch  SP6.227.1.05  
2:00p3:00p  Characterization and computation of optimal distributions for channel coding  Sean P. Meyn University of Illinois  UrbanaChampaign  SP6.227.1.05  
3:00p3:15p  Coffee  EE/CS 3176  SP6.227.1.05  
3:15p4:15p  Scheduling high speed data in (adversarial) wireless networks  Matthew Andrews Lucent Technologies  EE/CS 3180  SP6.227.1.05 
4:15p4:45p  Second Chances  EE/CS 3180  SP6.227.1.05  
5:00p6:30p  Reception and Poster Session  Lind Hall 400  SP6.227.1.05  
High SNR analysis of MIMO broadcast channels  Nihar Jindal University of Minnesota  
Cooperation vs. compression for sensor networks  Chulhan Lee University of Texas  Austin  
Effective capacity approach to providing statistical qualityofservice guarantees in wireless networks  Dapeng Wu University of Florida 
9:00a9:30a  Coffee  EE/CS 3176  SP6.227.1.05  
9:30a10:30a  Selforganizing control of network structure in wireless communication  Martin Greiner Siemens  EE/CS 3180  SP6.227.1.05 
10:30a11:00a  Coffee  EE/CS 3176  SP6.227.1.05  
11:00a12:00p  Control of multinode mobile Communications networks with time varying channels via stability methods  Harold J. Kushner Brown University  EE/CS 3180  SP6.227.1.05 
12:00p2:00p  Lunch  SP6.227.1.05  
2:00p3:00p  An optimization model of protocol stack and hetergeneous protocols  Steven Low California Institute of Technology  EE/CS 3180  SP6.227.1.05 
3:00p3:15p  Coffee  EE/CS 3176  SP6.227.1.05  
3:15p4:15p  Crosslayer control in wireless networks with QoS constraints  Eytan Modiano Massachusetts Institute of Technology  EE/CS 3180  SP6.227.1.05 
4:15p4:45p  Second Chances  EE/CS 3180  SP6.227.1.05 
9:00a9:30a  Coffee  EE/CS 3176  SP6.227.1.05  
9:30a10:30a  Spectrum Sharing Games  Randall A. Berry Northwestern University  EE/CS 3180  SP6.227.1.05 
10:30a11:00a  Coffee  EE/CS 3176  SP6.227.1.05  
11:00a12:00p  Structural results in cross layer optimization of wireless networks  Vikram Krishnamurthy University of British Columbia  EE/CS 3180  SP6.227.1.05 
12:00p1:30p  Lunch  SP6.227.1.05  
1:30p2:30p  Convergence and optimality of channel aware scheduling and resource allocation algorithms  Rajeev Agrawal Motorola, Inc.  EE/CS 3180  SP6.227.1.05 
2:30p3:30p  TBA  Kenneth L. Clarkson Bell Laboratories  EE/CS 3180  SP6.227.1.05 
3:30p4:00p  Coffee  EE/CS 3176  SP6.227.1.05  
4:00p5:00p  Crosslayer design for wireless networks  Ness Shroff Purdue University  EE/CS 3180  SP6.227.1.05 
5:00p5:30p  Second Chances  EE/CS 3180  SP6.227.1.05 
9:00a9:30a  Coffee  EE/CS 3176  SP6.227.1.05  
9:30a10:30a  Some Information theory and codes for halfduplex relays  Gerhard Kramer Lucent Technologies  EE/CS 3180  SP6.227.1.05 
10:30a11:00a  Coffee  EE/CS 3176  SP6.227.1.05  
11:00a12:00p  TBA  Colin D. Frank Motorola, Inc.  EE/CS 3180  SP6.227.1.05 
12:00p1:30p  Lunch  SP6.227.1.05  
1:30p2:30p  Overlay networks for wireless ad hoc networks  Christian Scheideler Johns Hopkins University  EE/CS 3180  SP6.227.1.05 
2:30p3:30p  Distributed canonical correlation and distortionrate analyses for centralized compressionestimation using wireless sensor networks  Georgios Giannakis University of Minnesota  EE/CS 3180  SP6.227.1.05 
3:30p4:00p  Coffee  EE/CS 3176  SP6.227.1.05  
4:00p5:00p  Heavy traffic models and control of wireless systems  Robert Buche North Carolina State University  EE/CS 3180  SP6.227.1.05 
5:00p5:30p  Second Chances  EE/CS 3180  SP6.227.1.05  
6:00p8:00p  Dinner  SP6.227.1.05 
8:30a9:00a  Coffee  EE/CS 3176  SP6.227.1.05  
9:00a10:00a  Mathematical problems in ad hoc wireless networks  Wing Shing Wong Chinese University of Hong Kong  EE/CS 3180  SP6.227.1.05 
10:00a10:15a  Coffee  EE/CS 3176  SP6.227.1.05  
10:15a11:15a  Optimization of IEEE 802.11 DCF based on Bayesian estimation of the number of competing terminals  Xiaodong Wang Columbia University  EE/CS 3180  SP6.227.1.05 
11:15a12:15p  Energy efficiency in multipleaccess wireless networks: Nash equilibria in power control games  Vincent Poor Princeton University  EE/CS 3180  SP6.227.1.05 
12:15p12:45p  Second Chances and Concluding Remarks  EE/CS 3180  SP6.227.1.05 
Event Legend: 

MS  Materials Seminar 
SP6.227.1.05  2005 Summer Program: Wireless Communication 
W6.811.05  Effective Theories for Materials and Macromolecules 
Cameron F. Abrams (Drexel University)  Systematic coarsegraining and concurrent multiresolution simulation of molecular liquids 
Abstract: Systematic coarsegraining is a class of techniques in which judicious approximations are invoked to coarsen a system of many degrees of freedom onto one with relatively fewer in a statistical mechanically consistent way. Collective variables are chosen and the resulting potentials of mean force at a given thermodynamic state are derived from the atomic level potential energy hypersurface. These techniques are briefly reviewed in their connection with the molecular simulation of specific synthetic polymers. Further developments incorporating onthefly coarsegraining into concurrent multiresolution simulations of simple molecular liquids are also discussed.  
Rajeev Agrawal (Motorola, Inc.)  Convergence and optimality of channel aware scheduling and resource allocation algorithms 
Abstract: With an abstraction of serving rateadaptive sources on a broadcasttype wireless channel as a utility maximization problem, it is shown how one can design many intuitive online scheduling policies based upon the feedback that one obtains at the scheduler. Using a stochastic approximation argument it is then shown that the constructed algorithms converge to optimal solutions of the utility maximization problem over different sets which critically depend on the quality of the feedback information. We then apply the theory developed above to the downlink in a CDMA based wireless network. In terms of operational variables the problem is to select a subset of the users for transmission at each transmission oppurtunity and for each of the users selected, to choose the modulation and coding scheme, transmission power, and number of codes used. We refer to this combination as the physical layer operating point (PLOP). Each PLOP consumes different amounts of code and power resources. Thus, the task is to pick the ``optimal'' PLOP taking into account both systemwide and individual user resource constraints that can arise in a practical system. Using an information theoretic model for the achievable rate per code results in a tractable convex optimization problem. By exploiting the structure of this problem, we give algorithms for finding the optimal solution with geometric convergence. We also use insights obtained from the optimal solution to construct low complexity near optimal algorithms that are easily implementable. Numerical results comparing these algorithms are also given.  
Silas Alben (New York University  Courant Institute)  A mechanical model of the teleost fin ray 
Abstract: This work considers the mechanics of fish swimming. In collaboration with the Lauder lab at Harvard, we are studying the structure of fish fin rays. Approximately half of all fish species utilize the same basic structurebody segments linked by a collagen networkto transduce fin ray shape and motion from a given input force. We present a simple coupled elastica model which uses only geometry and a single elastic constant to obtain the scalings of forces and displacements.  
Matthew Andrews (Lucent Technologies)  Scheduling high speed data in (adversarial) wireless networks 
Abstract: Wireless networks for transmitting high speed data are becoming increasingly common. Such networks lead to new and interesting scheduling problems, in large part because the quality of a wireless channel constantly changes over time. It is important to schedule in an opportunistic fashion, i.e. we want to transmit data between two users during the times when the associated wireless channel has good quality. A number of models have been proposed for studying such systems. These differ according to the assumptions made on the arrival process, the assumptions made on the channel conditions, and the metrics that are to be optimized. In this talk we shall survey some of these models and present contrasting scheduling results that arise in each model. We shall concentrate on the case in which the channel conditions are governed by an adversary and present limits on the optimum fairness and qualityofservice that can be achieved in the resulting adversarial environment.  
Marcel Arndt (University of Bonn)  Higher order gradient continuum description of atomistic models for crystalline solids 
Abstract: We propose an upscaling scheme for the passage from atomistic to continuum mechanical models for crystalline solids. It is based on an expansion of the deformation function up to a given order and leads to a continuum mechanical model which involves higher order gradients. The resulting model is an approximation of the atomistic system for a fixed and finite number of atoms within the quasicontinuum regime. The higher order terms allow the description of the microscopic material properties to a higher extent than commonly used continuum mechanical models. In particular, the discreteness effects of the underlying atomistic model are captured. Our upscaling technique is compared to other upscaling schemes and analyzed with respect to wellposedness and the asymptotic scale behavior. The qualitative properties of our technique are numerically studied for the model problem of a onedimensional atomic chain. The approach is then applied to the physically more relevant threedimensional example of a silicon crystal. The resulting approximation properties are studied.  
Paul Atzberger (Rensselaer Polytechnic Institute)  A stochastic immersed boundary method for biological fluid dynamics at microscopic length scales 
Abstract: With advances in cell and molecular biology there is an increasing interest in modeling microscopic systems at a coarse level where methods such as molecular dynamics become infeasible as a consequence of the wide range of active length and time scales. An alternative approach is to use a continuum description where neglected degrees of freedom of the system are accounted for by an effective model either through averaging or an appropriate stochastic model. In this poster an extension of the immersed boundary method [1] is presented for this purpose which includes appropriate stochastic forcing to model thermal fluctuations of the fluid and immersed structures. A stochastic numerical method is presented which deals with stiffness in the system by carefully handling statistical contributions of the dynamics of the fluid and immersed structures over long time steps. A number of physical checks are presented for the method which show for example that immersed particles diffuse with the appropriate scaling in the physical parameters and have the correct equilibrium statistics. The method is also demonstrated to reproduce wellknown hydrodynamic effects such as the 3/2 decay in the tail of the velocity autocorelation function of a Brownian particle. In conclusion, numerical results are presented for specific applications to polymers and membranes. [1] Peskin, C.S (2002), The immersed boundary method, Acta Numerica, 11, pp. 139.  
Randall A Berry (Northwestern University)  Spectrum Sharing Games 
Abstract: In wireless networks a key consideration is how to mitigate interference among multiple users in a given spectrum band. This is especially true in unlicensed or open bands, where users may be deployed without any centralized frequency planning or control. In this talk, we describe some simple mathematical models for sharing a given spectrum band. We discuss both a case where a spectrum manager controls access and a case where there is no manager and users implement a distributed algorithm to manage access. In the first case, we describe an auction mechanisms where the users bid for spectrum access. We model this auction as a game and characterize the equilibrium. In the second case, we discuss a distributed algorithm, in which users announce "price" signals which indicate the cost of interference to them. We relate this algorithm to a "fictitious" game, which in certain cases is supermodular. This relation is used to characterize the algorithms convergence. Extensions to multichannel networks will also be discussed, where users can allocate their power over multiple frequency bands, as in a OFDM system.  
Marian Bocea (University of Utah)  A nonlinear membrane model by means of Young measures 
Abstract: The integral representation of a relaxed functional arising in the derivation of a nonlinear membrane model is obtained in terms of a special class of Young measures generated by sequences of scaled gradients. Algebraic and analytical conditions on parametrized probability measures both necessary and sufficient to guarantee that they belong to this class are identified, in the spirit of Kinderlehrer and Pedregal's characterization of gradient Young measures. Joint work with Irene Fonseca.  
Sem C. Borst (Lucent Technologies  Bell Laboratories)  Flowlevel performance in wireless data networks 
Abstract: Channelaware scheduling strategies provide an effective mechanism for improving throughput performance in wireless data networks by exploiting channel fluctuations. In the talk, we focus on the flowlevel performance of channelaware scheduling algorithms in a dynamic setting with random finitesize data transfers. We show that in certain cases the flowlevel performance may be evaluated by means of a multiclass ProcessorSharing model where the total service rate varies with the total number of users. In addition, we present simple necessary conditions for flowlevel stability in the presence of channel variations, and establish that these are also sufficient for a broad class of utilitybased scheduling strategies and arbitrary rate statistics. Time permitting, we conclude with a discussion of capacity issues and flowlevel performance in wireless networks with multiple interacting base stations.  
Andrea Braides (II Università degli studi di Rome (Tor Vergata))  Simple lattice systems with complex macroscopic description 
Abstract: I will present a homogenized description of the simplest lattice systems, where the lattice energy depends on a variable that possesses only two states (without loss of generality we may take these two values as +1 and 1). The overall behavior of the system, as the number of nodes increases can be described, upon scaling, by a continuum expansion. in terms of Gammaconvergence. In the limit energies we may recognize bulk terms, interfacial energies, antiphase boundaries and microscopical oscillations, depending on the lattice parameters and shape. Some comments on the random case will also be given.  
Robert Buche (North Carolina State University)  Heavy traffic models and control of wireless systems 
Abstract: Heavy traffic methods are useful for wireline queueing analysis and show promise for wireless systems. The main difference compared to the wireline setting is the randomlyvarying environment in which wireless systems operate. In the heavy traffic analysis, typically a Brownian driven stochastic differential equation with reflection (SDER) models the queueing dynamics. We will discuss these models and the associated stochastic control problem along with some numerical simulation results. Recently, the importance of modeling long range dependence in wireless systems has been shown. We will give some initial comments on extending the analysis to this case where the SDER is driven by a more general Levy process.  
Antonio Di Carlo (Università degli Studi Roma Tre)  Microtwists & Nanodefects 
Abstract: Abstract: Prototype nanoelectromechanical devices incorporating individual multiwall carbon nanotubes as torsion bars or rotary bearings have been fabricated and tested by various groups. Typical length scales are: 1 micron for the overall span, 25 nm for the diameter, 0.5 nm for the interwall gap. The experimental evidence collected so far is puzzling, pointing out a need for a better understanding of the interwall mechanical coupling mechanisms. We speculate that the basic mechanism behind progressive interwall coupling is the formation of bridging defects, that is, covalent links between adjacent walls, triggered by inward migration of chromium atoms (which are evaporated onto the outer wall of the nanotube when fabricating the device).  
Philip Fleming (Motorola, Inc.)  System analysis of wireless packet networks carrying voice over IP 
Abstract: Joint work with Amitava Ghosh and Ivan Vukovic. This tutorial will cover the system architecture, protocol design and performance characteristics of voice and other quasirealtime applications such as pushtotalk over wireless packet networks. We address features of the bearer path such as voice coding and IP header compression as well as control plane characteristics such as call setup and handoff latency. We will give an overview of the next generation wireless wide area network technologies, HRPD (EVDO), HSUPA/HSDPA and 802.16e and present analysis and simulation of system behavior for each under moderate and heavy loading conditions using both real and nonrealtime traffic and mixtures. Packet scheduling and media access control will also be discussed in some detail. Toward the end of the tutorial we will discuss open research areas.  
Georgios Giannakis (University of Minnesota)  Distributed canonical correlation and distortionrate analyses for centralized compressionestimation using wireless sensor networks 
Abstract: Wireless sensor networks deployed to perform surveillance and
monitoring tasks have to operate under stringent energy and
bandwidth limitations. These motivate well distributed compression
and estimation scenarios based on reduced dimensionality sensor
observations which may have to be severely quantized before
transmission to a fusion center. We will show how distributed
correlation analysis can be used to compress observations and
explore the fundamental performance limits dictated by distortionrate
analysis in this decentralized estimation setup. We will further
present interesting tradeoffs that emerge even in distributed
meanlocation estimation based on severely quantized observations
along with their fundamental errorvariance limits. Estimators
utilizing either independent or colored binary data will be
developed and analyzed. Corroborating simulations will provide
comparisons with the clairvoyant estimators based on unquantized
sensor observations, and include a motivating application with a
sensor net employed for habitat monitoring. In the poster session
we will also discuss dynamical systems and present (extended)
Kalman Filtering ideas based on singlebit observations.
Brief Bio: G. B. Giannakis received his B.Sc. in 1981 from the Ntl. Tech. Univ. of Athens, Greece and his M.Sc. and Ph.D. in Electrical Engineering in 1983 and 1986 from the Univ. of Southern California. Since 1999 he has been a professor with the Department of Electrical and Computer Engineering at the University of Minnesota, where he now holds an Endowed ADC Chair in Wireless Telecommunications. His general interests span the areas of communications and signal processing, estimation and detection theory  subjects on which he has published more than 200 journal papers, 350 conference papers, and two edited books. Current research focuses on complexfield and spacetime coding, multicarrier, ultrawide band wireless communication systems, crosslayer designs and wireless sensor networks. He is the (co) recipient of six best paper awards from the IEEE Signal Processing (SP) and Communications Societies (1992, 1998, 2000, 2001, 2003, 2004) and also received the SP Society's Technical Achievement Award in 2000. He is an IEEE Fellow since 1997 and has served the IEEE in various editorial and organizational posts. 

Antoine Gloria (CERMICS  ENPC)  A direct approach to numerical homogenization in finite elasticity 
Abstract: We present a direct approach to tackle the numerical simulation of a homogenized problem in nonlinear elasticity at finite strain. We provide an approximation result for this problem and derive an error estimate in the particular case of convex energy densities. We have implemented this approach in a nonlinear elasticity solver and performed several numerical tests on idealized rubber foams.  
Martin Greiner (Siemens)  Selforganizing control of network structure in wireless communication 
Abstract: Wireless multihop ad hoc communication networks represent an infrastructureless peertopeer generalization of todays cellular networks. Since a central control authority is missing, the complex network has to selforganize itself for various operating tasks. Key is the design of simple, yet robust distributive control rules, which allow the overall network to perform well. Two examples from topology control are given. The first one addresses the connectivity issue, where a selforganizing rule is presented and shown to lead to strong network connectivity almost surely. A generic packettraffic analysis is used in the second example to first develop a phenomenological description of the endtoend throughput capacity for fixed network structures and then to sketch further steps towards a selforganizing rule for obtaining throughputoptimized network structures.  
Nihar Jindal (University of Minnesota)  High SNR analysis of MIMO broadcast channels 
Abstract: The behavior of the multiple antenna broadcast channel at high SNR is investigated. The sum rate capacity (achievable by dirty paper coding), the sum rate achievable using transmitter beamforming, and an upper bound to the sum rate capacity are studied. Though these three terms are equivalent in the sense of the multiplexing gain, i.e. in terms of first order growth, there is an absolute difference between the corresponding rates. These difference terms are calculated and simple and intuitive geometrical interpretations are given.  
Gerhard Kramer (Lucent Technologies)  Some Information theory and codes for halfduplex relays 
Abstract: A relay channel has a source terminal transmitting a message to a destination terminal with the help of one or more relays. We review a selection of the existing information theory for such channels, with emphasis on halfduplex models. We further consider aspects of code and receiver design, including phase and symbol synchronization.  
Vikram Krishnamurthy (University of British Columbia)  Structural results in cross layer optimization of wireless networks 
Abstract: In the first part of the talk, we consider the interaction between the physical and link layers for single user systems. By using a Lagriangian approach to constrained Markov decision processes and stochastic dominance results, we examine the structural effects of buffer size, fading channel dynamics and traffic dynamics on system throughput. Also a channel aware ARQ protocol is proposed that uses a partially observed Markov deicision process to optimize the tradeoff between latency and throughput. In the second part of the talk, we consider cross layer admission control and vertical handoff between WLAN and CDMA networks for multiuser systems. We present gradient learning based stochastic approximation algorithms to optimize the resulting constrained Markov decision process.  
P. R. Kumar (University of Illinois  UrbanaChampaign)  Capacity, architecture, and protocols for ad hoc wireless networks 
Abstract: Topics This tutorial is motivated by two considerations. (i) There has been some progress in recent years in developing a quantitative framework for wireless networks. (ii) The research community is entering a phase of designing several second generation protocols for wireless networks which aim to not only improve performance, but also to address unmet needs. Our goal in this tutorial is twofold: (i) We will provide a clear presentation of the key ideas underlying this emerging theory of wireless networks. The goal is to make the theory accessible to all researchers in the area, to understand the questions addressed, the questions unaddressed, the methods used, and address its shortcomings, as well as its results, i.e., basically to understand it. (ii) We will provide some candidate second generation protocol designs. In particular we will stress the importance of paying attention to the architecture of the implementation. We will also address some issues related to the emerging topic of crosslayer design. We will also stress the importance of implementing designs.  
Harold J. Kushner (Brown University)  Control of multinode mobile Communications networks with time varying channels via stability methods 
Abstract: Consider a communications network consisting of mobiles, each of which can be scheduled to serve as a receiver and/or transmitter. Data from many external sources arrives at the various mobiles in some random way. Each mobile can serve as a node in the possibly multihop path from source to destination. At each mobile the data is queued according to the sourcedestination pair until transmitted. Time is divided into small scheduling intervals. The connecting channels are randomly varying due to the motion of the mobiles and consequent scattering. At the beginning of the intervals, the channels are estimated via pilot signals and this information is used for scheduling. The issues are the allocation of transmission power and/or time and bandwidth to the various queues at the various mobiles in a queue and channelstate dependent way to assure stability and good operation. Lost packets might or might not have to be retransmitted. The decisions are made at the beginning of the scheduling intervals. In a recent work, stochastic stability methods were used to develop scheduling policies for the simple system where there is a single transmitter communicating with many mobiles. The resulting controls were readily implementable and allowed a range of tradeoffs between current rates and queue lengths, under very weak conditions. Here the basic methods and results are extended to the network case. The choice of Liapunov function allows a choice of the effective performance criteria. All essential factors are incorporated into a "mean rate" function, so that the results cover many different systems. Because of the nonMarkovian nature of the problem, we use the perturbed Stochastic Liapunov function method, which is designed for such problems.  
Claude Le Bris (CERMICS)  Inserting computational chemistry in materials science: a guided tour 
Abstract: We will introduce the audience to the basic modelling in computational quantum chemistry. We will overview the mathematical and numerical aspects, pointing out some recent works. A special emphasis will be laid upon the approaches used for large size systems, and, beyond, the different methods coupling quantum chemistry models and models of materials science.  
Chulhan Lee (University of Texas  Austin)  Cooperation vs. compression for sensor networks 
Abstract: In a sensor network, nodes share information about their observations, and the amount of shared information can often be substantial. This paper compares two different strategies that exploit this redundant information  compression and cooperation. It finds compression to be the winning strategy when energy savings is the most important objective, but finds cooperation to be the throughput maximizing strategy. A weighted optimization problem is formulated to obtain intermediate schemes that allow a critical level of cooperation in the system, thereafter compressing all other redundant information.  
Xiantao Li (University of Minnesota)  Boundary conditions for molecular dynamics 
Abstract: At the atomic scale, crystalline solids can be modelled by Molecular dynamics (MD), which provides a very useful tool to study crystal structure and defect dynamics. MD simulations can be conducted either in isolation, with some experimental loading condition applied to its boundary, or they can be coupled with a continuum model replacing all the atoms outside of the atomistic region. In both cases, a key issue is to eliminate the reflection of phonons at the boundary or the continuum/atomistic interface. In this talk, I will present a variational formulation for constructing boundary conditions that suppress phonon reflections. Local boundary conditions, which are practical for computational purpose, are obtained from this formulation. A few examples, including 1D chain, 2D triangular lattice, 3D BCC lattice and Graphene (complex lattice) will be given. Finally we apply these boundary conditions to fracture simulations. This is joint work with Weinan E (Princeton).  
Steven Low (California Institute of Technology)  An optimization model of protocol stack and hetergeneous protocols 
Abstract: Can we integrate the various protocol layers into a single coherent theory by regarding them as carrying out an asynchronous distributed primaldual computation over the network to implicitly solve a global optimization problem? Different layers iterate on different subsets of the decision variables using local information to achieve individual optimalities, but taken together, these local algorithms attempt to achieve a global objective. Such a theory will expose the interconnection between protocol layers and can be used to study rigorously the performance tradeoff in protocol layering as different ways to distribute a centralized computation. We describe some preliminary work on cross layer interactions involving HTTP, TCP, IP, MAC, and scheduling. All of these instances can be integrated within a utility maximization model. We present equilibrium and stability properties of networks shared by TCP sources that react to different pricing signals where the current utlity maximization model breaks down.  
Dionisios Margetis (Massachusetts Institute of Technology)  Continuum approach to crystal surface morphology evolution 
Abstract: The design of small devices with novel properties relies on the synthesis and stability of nanoscale surface structures. At temperatures below roughening crystal surfaces have flat, macroscopic regions known as "facets'' and evolve via the motion of interacting atomic steps. This talk describes macroscopic evolution laws on the basis of the microscopic step motion. First, continuum evolution equations in (2+1) dimensions are derived from kinetic considerations; the surface height profile outside facets satisfies a nonlinear PDE that accounts for mass fluxes parallel and transverse to steps via an appropriate tensor mobility. Second, the PDE is tested through comparisons of analytical predictions with experimental results and numerical simulations that follow the motion of individual steps. The challenging problem of suitable boundary conditions at the boundaries of facets is discussed.  
Kevin W. Mclaughlin (University of Wisconsin  River Falls)  On the use of topological indices in quantitative structureproperty relationships for macromolecules 
Abstract: Chemical graph theory has been extensively applied to predicting the physical properties of small molecules through quantitativestructure property relationships (QSPR). This has been accomplished by demonstrating strong correlations between physical properties and one or more topological indices. Extending the application of topological indices to macromolecules can lead to potential problems for such models. Using the Hosoya index, we illustrate both the problems associated with degeneracy of a topological index as molecular size and complexity increases, and what limits should be placed on the development of such models.  
Sean P. Meyn (University of Illinois  UrbanaChampaign)  Characterization and computation of optimal distributions for channel coding 
Abstract: This presentation concerns the structure of optimal codes for stochastic channel models. An investigation of an associated dual convex program reveals that the optimal distribution in channel coding is typically discrete. Based on this observation we construct a new class of algorithms is introduced, based on the cuttingplane method, to generate discrete distributions that are optimal within a prescribed class. This lecture builds upon a tutorial lecture to be presented by Meyn prior to the workshop at IMA.  
Eytan Modiano (Massachusetts Institute of Technology)  Crosslayer control in wireless networks with QoS constraints 
Abstract: In this talk we will describe algorithms for resource allocation in wireless networks that attempt to optimize network performance across multiple layers of the protocol stack. In the first part of the talk we will consider the joint problem of flow control, routing, and scheduling in a wireless network subject to Quality of Service requirements. In particular, we will describe a dynamic control strategy that maximizes the sum utility in the network; and can be used to achieve a wide range of fairness objectives. In the second part, we consider a wireless transmitter whose data rate can be controlled by varying the transmission power. For such a system we will describe optimal transmission policies that satisfy delay constraints and also minimize the total transmission energy expenditure.  
Barbara Niethammer (Humboldt Universität zu Berlin)  The effect of screening and correlations in Ostwald ripening 
Abstract: The classical theory by Lifshitz, Slyozov and Wagner describes diffusion limited coarsening of particles in the limit of vanishing volume fraction. Due to several shortcomingis of the LSW theory first order corrections in terms of the volume fraction should be taken into account. We discuss a new method to effeciently identify firstorder corrections in a statistically homogeneous system. The key idea is to relate the full system of particles to systems where a finite number of particles has been removed. This method allows to decouple screening and correlation effects and allows to effiently evaluate conditional expected values of the particle growth rates.  
Hans Christian Oettinger (ETHZ)  Thermodynamic framework for systematic coarsegraining of atomistic models for fluids 
Abstract: For this talk, I distinguish between two fundamentally different simulation approaches in materials science, "bruteforce simulations" and "thermodynamically guided simulations." Bruteforce simulations can be thought of as computer experiments mimicking the physical situation of interest directly on a computer; thermodynamically guided simulations rely on a nonequilibrium statistical ensemble containing the variables of some coarsegrained description of the system of interest. The availability of an appropriate coarsegrained level of description is thus crucial for thermodynamically guided simulations and should be considered as a reasonable price to pay for bridging widely separated time scales (and deeper understanding). The above remarks are elaborated in the context of molecular dynamics simulations of Lennard Jones fluids and of polymer melts. It is shown how simulations based on nonequilibrium ensembles can help to bridge the wide range of time scales from monomer motions to polymer processing. The importance of coarsegrained models for specifying an ensemble and for identifying suitable quantities of interest is illustrated.  
Harald Pleiner (Max Planck Institute for Polymer Research)  General nonlinear hydrodynamic description of nonNewtonian fluids 
Abstract: We review conventional constitutive equations for nonNewtonian fluids from a hydrodynamic point of view. Using general thermodynamic and symmetry arguments and applying valid physical principles we describe viscoelasticity by setting up nonlinear dynamic equations either for a relaxing (Eulerian) strain tensor or for a transient orientational order parameter tensor. This covers the usual nonNewtonian effects, like shear thinning, strain hardening, stress overshoot, normal stress differences and non exponential stress relaxation. In both cases an effective dynamic equation for the stress tensor can be derived in terms of a power series and compared with conventional nonNewtonian rheological models. It is more general in structure than those, comprises most, restricts some, and discards a few of them. In addition, we generalize this approach into a 2fluid description for multicomponent fluids, which is appropriate, when the relative velocity of the different components is relaxing slowly. Special emphasis is laid on nonlinearities involving velocities that are governed by symmetry and other general invariance principles. It is shown that the proper velocities, with which the dynamic quantities are transported and convected, cannot be chosen at will, since there are subtle relations among them. Within allowed combinations the convective velocities are generally material dependent and not fixed by general principles. The socalled stress division problem, i.e. how the total stress is distributed between the different components, is shown to depend partially on the choice of the convected velocities, but is otherwise also material dependent. A set of reasonably simplified equations is given for viscoelastic fluids, polymeric gels, and ferrofluids focusing on an effective concentration dynamics that may be used for comparison with experiments.  
Vincent Poor (Princeton University)  Energy efficiency in multipleaccess wireless networks: Nash equilibria in power control games 
Abstract: The energy efficiency (measured in bitsperJoule) of multipleaccess wireless data networks is considered via the behavior of Nash equilibria in noncooperative power control games. Particular issues considered include the effects of multiuser detection and multiple antennas on energy efficiency, energy efficient carrier loading in multicarrier CDMA systems, and the effects of delay constraints on energy efficiency. Some open problems of interest are also discussed.  
Tiezheng Qian (Hong Kong University of Science and Technology)  Slip boundary condition for the moving contact line in immiscible twophase flows 
Abstract: From extensive molecular dynamics simulations on immiscible twophase flows, we find the relative slipping between the fluids and the solid wall everywhere to follow the generalized Navier boundary condition, in which the amount of slipping is proportional to the sum of tangential viscous stress and the uncompensated Young stress. The latter arises from the deviation of the fluidfluid interface from its static configuration. We give a continuum formulation of the immiscible flow hydrodynamics, comprising the generalized Navier boundary condition, the NavierStokes equation, and the CahnHilliard interfacial free energy. Our hydrodynamic model yields interfacial and velocity profiles matching those from the molecular dynamics simulations at the molecularscale vicinity of the contact line.  
Weiqing Ren (Princeton University)  Multiscale modeling of contact line dynamics 
Abstract: The moving contact line (MCL) problem is analyzed using the multiscale methods developed recently by Ren and E. It is wellknown that the noslip boundary condition results in a nonintegrable singularity in the stress at the contact line. Numerous empirical slip models have been proposed to remove the stress singularity. For the multiscale method, we solve the NavierStokes (NS) equations for the macroscale flow field, and calculate the needed boundary condition, e.g., the shear stress, at the contact line region based on molecular dynamics (MD). In the talk, we will discuss the details of the multiscale method, the validation study, and the results on large scale contact line problem.  
Christian Scheideler (Johns Hopkins University)  Overlay networks for wireless ad hoc networks 
Abstract: In this talk I will give an overview of various techniques to organize Wireless nodes in an overlay network with nearoptimal communication Paths between any pair of nodes. Many of these overlay network constructions are based on the theory of graph spanners. Spanners first appeared in computational geometry, were then discovered as an interesting tool for approximating NPhard problems, and have recently also attracted a lot of attention in the context of routing and topology control in wireless ad hoc networks. After introducing the concept of graph spanners and giving several Examples relevant for wireless ad hoc networks, I will discuss various distributed, selfstabilizing protocols for maintaining a spanner among the wireless nodes, using a very simple wireless communication model just to provide a proof of concept. Afterwards, I will also discuss a much more realistic wireless communication model that has just recently been published, and I will demonstrate how to design a selfstabilizing overlay network protocol within that model.  
James P. Sethna (Cornell University)  Estimating systematic errors: sloppy models 
Abstract: Joint work with Søren Fredericksen, Karsten W. Jacobsen, and Kevin S. Brown Science is filled with multiparameter models that must be fit to observations. An ecosystem has many interacting species, a cell has interacting proteins and genes, and a material has many atoms whose forces are governed by quantummechanical electronic calculations. A key question for these models is when we can trust their predictions: usually only wisdom and experience can judge for which problems a given model will likely be reliable. One source of unreliability in these models is that they are sloppy: the parameters are illdetermined by the data, with enormous ranges giving roughly equivalent fits. These parameters giving roughly equivalent fits, however, do not yield the same predictions! By using an ensemble of good parameter sets, we have been able to produce `sloppy model' estimates of the errors in one particular system: the interatomic potential for the element Molybdenum. Our error estimates capture most of the systematic error in this system, for three different forms of the interatomic potential.  
Vivek Shenoy (Brown University)  Selfassembly and shape transitions of epitaxial nanowires and strained monolayer islands 
Abstract: Several interesting shape transitions have been recently observed during the growth of submonolayer islands on latticemismatched substrates. These shapes, which allow relaxation of mismatch strain, include nanowires that are elongated along certain crystallographic directions with widths in the singledigit nanometer range, shapes that show concave boundaries in equilibrium and formation of highly ramified or branched structures during growth. In this talk, I will present a sharp interface model and a phasefield model to study the shapes (kinetic and equilibrium) of individual islands and stability and coarsening kinetics of monolayer island arrays. Our model includes the kinetics of adatom diffusion on the terraces and island edges, attachment kinetics to islands, substratemediated elastic interactions between the islands and anisotropies associated with the creation of island edges. Particular emphasis will be given to selfassembled growth of regular arrays of epitaxial nanowires that have potential applications as nonlithographically fabricated interconnects.  
Ness Shroff (Purdue University)  Crosslayer design for wireless networks 
Abstract: Joint work with Xiaojun Lin. In this talk we develop an optimal crosslayer solution for rate control in multihop wireless networks. In particular, we study the impact on the performance of crosslayer rate control if the network control and information from the lower layers is imperfect, a practical reality in communication networks. We establish desirable results on the performance bounds of crosslayered rate control under an imperfect platfrom. Our crosslayered approach provides provably better performance bounds when compared with a layered approach (that does not design rate control and scheduling together). The insights drawn from our analyses also enable us to design a fully distributed crosslayered rate control and scheduling algorithm under a restrictive interference model.  
Peter Smereka (University of Michigan)  Computations of strained heteroepitaxy in 3 dimensions using kinetic Monte Carlo 
Abstract: The growth of strained heteroepitaxial films in 3 dimensions using a SolidonSolid model is discussed. Elastic effects are included by using a ball and spring model. The system is evolved in time using a kinetic Monte Carlo method. Discrete models of this form naturally include nanoscale effects, such as nucleation, which are difficult to incorporate in continuum models. On the other hand, it is more computationally intensive to use these discrete models simulate film growth on experimentally relevant length scales. This talk will discuss some of the computational challenges and approaches we have developed for simulation of heteroepitaxy. In addition, some preliminary results of film growth will be presented which shows that when the elastic effects are small the film grows in a layerbylayer fashion. However, when the elastic effects become strong we observe mound formation (selfassembled quantum dots).  
Florian Theil (University of Warwick)  From discrete to continuum systems: Crystallization in two dimensions 
Abstract: While the analysis of contiuum models of spatially extended systems is a well studied mathematical discipline, much less is know about the relation between discrete systems and their continuum limits. I will highlight some of the challenges which arise when passing from discrete to continuum scales and give an overview of recent mathematical developments. A fundamental challenge in this area is the crystallization problem where one attempts to characterize the asymptotic behavior of the ground state of N particles that interact via LennardJones type potentials with each other. I will report on new mathematical results which partically solve this problem.  
Qi Wang (Florida State University)  A paradigm of kinetic theories for suspensions and nematic polymers 
Abstract: In this talk, I will present a systematic approach to the development of kinetic theories for suspensions and nematic polymers ranging from rigid bodies to deformable ones. The theories account for the molecular configuration of the suspensions and polymers. For example, the kinetic theory for biaxial liquid crystal polymers account for the broken symmetry at the molecular level in the transport equation for the number density function as well as the mesoscopic stress tensor calculation. We will discuss the connection with the existing kinetic theories and give some examples in simple flows.  
Xiaodong Wang (Columbia University)  Optimization of IEEE 802.11 DCF based on Bayesian estimation of the number of competing terminals 
Abstract: The performance of the Distributed Coordination Function (DCF) of the IEEE 802.11 protocol has been shown to heavily depend on the number of terminals accessing the distributed medium. The DCF uses a carrier sense multiple access scheme with collision avoidance (CSMA/CA) where the backoff parameters are fixed and determined by the standard. While those parameters were chosen to provide a good protocol performance under light loads, they fail to provide an optimum utilization of the channel in many scenarios. In particular, under heavy load scenarios, the utilization of the medium can drop tenfold. Most of the optimization mechanisms proposed in the literature are based on adapting the DCF backoff parameters to the estimate of the number of competing terminals in the network. However, existing estimation algorithms are either inaccurate or too complex. In this paper we propose an enhanced version of the IEEE 802.11 DCF that employs an adaptive estimator of the number of competing terminals based on sequential Monte Carlo methods. The algorithm uses a Bayesian approach, optimizing the backoff parameters of the DCF based on the predictive distribution of the number of competing terminals. We show that our algorithm is simple yet highly accurate even at small time scales. We implement our proposed new DCF in the ns2 simulator and show that it outperforms existing methods. We also show that its accuracy can be used to improve the results of the protocol even when the nodes are not in saturation mode. Moreover, we show that there exists a Nash equilibrium strategy that prevents rogue nodes from changing their parameters for their own benefits, making the algorithm applicable in a complete distributed fashion without having to modify the standard or the existing base stations.  
Wing Shing Wong (Chinese University of Hong Kong)  Mathematical problems in ad hoc wireless networks 
Abstract: In this talk, we discuss selected problems arising from ad hoc wireless networks, problems such as the fairness in routing and distributed state estimation. We show how these problems lead naturally to concepts such as generalized PerronFrobenius eigenvectors, von Neumann equilibrium, and low data rate distributed controller, as well as to Baynesian decision function and stochastic approximation.  
Dapeng Wu (University of Florida)  Effective capacity approach to providing statistical qualityofservice guarantees in wireless networks 
Abstract: The nextgeneration wireless networks are targeted at supporting various applications such as voice, data, and multimedia with diverse quality of service (QoS) requirements. To provide explicit QoS guarantees such as a data rate, delay bound, and delaybound violation probability triplet, it is necessary to analyze a QoS provisioning system in terms of these QoS measures. This task requires characterization of the service (channel modeling), and queueing analysis of the system. However, the existing channel models such as finitestate Markov chain models, do not explicitly characterize a wireless channel in terms of these QoS measures. This leads to high complexity in characterizing the relation between the control parameters of QoS provisioning and the calculated QoS measures. Recognizing that the above difficulty is the lack of a channel model that can easily relate the control parameters of a QoS provisioning system to the QoS measures, we propose and develop a linklayer channel model termed the effective capacity (EC) model. The EC model captures the effect of channel fading on the queueing behavior of the link, using a computationally simple yet accurate model, and thus, is a critical tool for designing efficient QoS provisioning mechanisms. Such an approach to channel modeling and QoS provisioning, is called effective capacity approach. In this poster, I will present our effective capacity approach to channel modeling.  
Hong Zhou (Naval Postgraduate School)  Anchoring distortions coupled with plane Couette and Poiseuille flows of nematic polymers 
Abstract: The aim of this work is to model and simulate Processinginduced heterogeneity in rigid, rodlike nematic polymers In viscous solvents. We employ a mesoscopic orientation tensor model due to Doi, Marrucci and Greco which extends the small molecule, liquid crystal theory of LeslieFrank to nematic polymers. We focus simulations in the regime of weak flow and strong distortional elasticity to expose the effects due to wall anchoring conflicts. A remarkably simple diagnostic emerges in this physical parameter regimes, in which salient morphology features are controlled by the amplitude and sign of the difference in plate anchoring angles of the director field at the two plates.  
Erik van der Giessen (University of Groningen )  Dislocation field theory in 2D: formulation and validation 
Abstract: Plastic deformation of crystalline metals at the scale of micrometers and smaller is often size dependent, particularly in the presence of strain gradients. Standard local theories are not able to capture these size effects because they lack a material length scale. Therefore, numerous nonlocal models have been proposed during the last decade, the majority of which are phenomenological straingradient theories. An alternative description will be presented here, which is termed Dislocation Field Theory (DFT). It is based on a rigorous statistical averaging of the dislocation motion of edge dislocations gliding on a single slip system. The resulting field equations are then coupled to a crystal plasticity model using Orowan's relation. The resulting DFT is subsequently generalized to multipe slip, albeit in two dimensions. The main characteristic that distinguishes DFT from other plastic straingradient theories is that the material length scale the average dislocation spacing is not a material constant but evolves with deformation. It will be shown how the few material parameters in DFT are fitted to discrete dislocation results for one particular problem, and how the subsequent predictions of the theory for other problems compares with discrete dislocation simulations. The problems addressed include shearing of a model composite; constrained shear; bending; and stress relaxation in a thin film. 
Cameron F. Abrams  Drexel University  6/7/2005  6/11/2005 
Prathima Agrawal  Auburn University  6/26/2005  6/30/2005 
Rajeev Agrawal  Motorola, Inc.  6/26/2005  7/1/2005 
In Soo Ahn  Bradley University  6/21/2005  7/1/2005 
Silas Alben  Harvard University  6/7/2005  6/12/2005 
Jeffrey G. Andrews  University of Texas  Austin  6/21/2005  7/1/2005 
Matthew Andrews  Lucent Technologies  6/26/2005  7/1/2005 
Marcel Arndt  University of Bonn  6/7/2005  6/12/2005 
Douglas N. Arnold  University of Minnesota  7/15/2001  8/31/2006 
Donald G. Aronson  University of Minnesota  9/1/2002  8/31/2005 
Festus Asemota  University of Benin  6/20/2005  7/3/2005 
Alexei Ashikhmin  Lucent Technologies  Bell Laboratories  6/26/2005  7/1/2005 
Paul Atzberger  Rensselaer Polytechnic Institute  6/8/2005  6/11/2005 
Gerard Awanou  University of Minnesota  9/2/2003  8/31/2005 
Francois Baccelli  Ecole Normale Superieure  6/26/2005  7/1/2005 
Yuliy Baryshnikov  Bell Laboratories  6/8/2005  6/11/2005 
James Berger  Duke University  6/16/2005  6/18/2005 
Randall A. Berry  Northwestern University  6/26/2005  7/1/2005 
Marian Bocea  University of Utah  6/7/2005  6/11/2005 
Sem C. Borst  Lucent Technologies  Bell Laboratories  6/26/2005  7/1/2005 
Nigel Boston  University of Wisconsin  6/26/2005  7/1/2005 
Andrea Braides  II Università degli studi di Rome (Tor Vergata)  6/1/2005  6/15/2005 
Robert Buche  North Carolina State University  6/21/2005  7/1/2005 
MariaCarme Calderer  University of Minnesota  9/1/2004  6/30/2005 
Eric Cances  CERMICS  6/8/2005  6/12/2005 
Pedro Ponte Castaneda  Ecole Polytechnique  6/7/2005  6/11/2005 
Dov Chelst  DeVry University  6/21/2005  7/3/2005 
Qianyong Chen  University of Minnesota  9/1/2004  8/31/2006 
RongRong Chen  University of Utah  6/21/2005  6/29/2005 
AeGyeong Cheong  Clemson University  5/13/2005  6/13/2005 
Kenneth L. Clarkson  Bell Laboratories  6/26/2005  7/1/2005 
Cristina Comaniciu  Stevens Institute of Technology  6/26/2005  7/1/2005 
Brian Conrey  American Institute of Mathematics  6/16/2005  6/18/2005 
Antonio DeSimone  SISSAItaly  3/10/2005  7/15/2005 
Antonio Di Carlo  Università degli Studi Roma Tre  4/10/2005  6/12/2005 
Brian DiDonna  University of Minnesota  9/1/2004  8/31/2006 
Nicolas P. Dirr  Max Planck Institute for Math in the Sciences  6/6/2005  6/12/2005 
Georg Dolzmann  University of Maryland  5/31/2005  6/3/2005 
Tyrone Duncan  University of Kansas  6/26/2005  7/1/2005 
Kossi Delali Edoh  Elizabeth City State University  6/21/2005  7/1/2005 
Martin Eiger  Telcordia Technologies  6/26/2005  7/1/2005 
David Eisenbud  Mathematical Sciences Research Institute  6/16/2005  6/18/2005 
Ryan S. Elliott  University of Michigan  1/1/2005  6/30/2005 
Guler Ergun  University of BathUK  6/7/2005  6/12/2005 
Dean Evasius  National Science Foundation  6/17/2005  6/19/2005 
Ali Eydgahi  Unversity of Maryland Eastern Shore  6/21/2005  7/2/2005 
Philip Fleming  Motorola, Inc.  6/22/2005  6/24/2005 
Colin D. Frank  Motorola, Inc.  6/26/2005  7/1/2005 
Avner Friedman  Ohio State University  6/16/2005  6/19/2005 
Gero Friesecke  University of Warwick  6/4/2005  6/11/2005 
Tim Garoni  University of Minnesota  8/25/2003  8/31/2005 
Adriana Garroni  Università di Roma La Sapienza  6/1/2005  6/15/2005 
Eugene C. Gartland Jr.  Kent State University  1/10/2005  6/30/2005 
Georgios Giannakis  University of Minnesota  6/21/2005  7/1/2005 
Antoine Gloria  CERMICS  ENPC  5/25/2005  6/12/2005 
Mark Green  California State University  Los Angeles  6/16/2005  6/18/2005 
Martin Greiner  Siemens  6/25/2005  7/2/2005 
Phillip A. Griffiths  Institute for Advanced Study  6/17/2005  6/18/2005 
Colette Guillope  University of Paris XII  6/6/2005  6/14/2005 
Robert Gulliver  University of Minnesota  9/1/2004  6/30/2005 
Katherine Guo  Bell Laboratories  6/26/2005  7/3/2005 
Rohit Gupta  University of Minnesota  6/22/2005  7/1/2005 
ChuanHsiang Han  University of Minnesota  9/1/2004  8/31/2005 
Nidhi Hegde  France Telecom  6/21/2005  7/1/2005 
John Hobby  Bell Laboratories  6/26/2005  7/1/2005 
Michael L. Honig  Northwestern University  6/26/2005  7/1/2005 
Qun Huo  North Dakota State University  6/7/2005  6/11/2005 
Syed Ali Jafar  University of California  Irvine  6/22/2005  7/1/2005 
Richard D. James  University of Minnesota  9/1/2004  6/30/2005 
Arulsaravana Jeyaraj  University of California  Irvine  6/21/2005  7/1/2005 
Chuanyi Ji  Georgia Institute of Technology  6/22/2005  7/1/2005 
Shi Jin  University of Wisconsin  1/4/2005  6/30/2005 
Yasong Jin  University of Kansas  6/21/2005  7/2/2005 
Nihar Jindal  University of Minnesota  6/22/2005  7/2/2005 
Sookyung Joo  University of Minnesota  9/1/2004  8/31/2006 
Vladimir Kamotski  University of BathUK  5/24/2005  6/14/2005 
Chiu Yen Kao  University of Minnesota  9/1/2004  8/31/2006 
Sang Wu Kim  Iowa State University  6/22/2005  6/25/2005 
Robert V. Kohn  New York University  6/6/2005  6/10/2005 
Soumitri Kolavennu  Honeywell  6/26/2005  7/1/2005 
Richard Kollar  University of Minnesota  9/1/2004  8/31/2005 
Gerhard Kramer  Lucent Technologies  6/26/2005  7/1/2005 
Vikram Krishnamurthy  University of British Columbia  6/26/2005  7/1/2005 
Komandur R. Krishnan  Telcordia Technologies  6/27/2005  7/1/2005 
P. R. Kumar  University of Illinois  UrbanaChampaign  6/21/2005  7/1/2005 
Matthias Kurzke  University of Minnesota  9/1/2004  8/31/2006 
Harold J. Kushner  Brown University  6/26/2005  7/1/2005 
Batool Labibi  K. N. Toose University of Technology  6/21/2005  7/2/2005 
Christopher J. Larsen  Worcester Polytechnic Institute  6/7/2005  6/12/2005 
Claude Le Bris  CERMICS  6/1/2005  6/17/2005 
Chulhan Lee  University of Texas  Austin  6/22/2005  7/2/2005 
Sungyun Lee  Korea Advanced Institute of Science & Technology  6/7/2005  6/11/2005 
Frederic Legoll  University of Minnesota  9/3/2004  8/31/2006 
Debra Lewis  University of Minnesota  7/15/2004  8/31/2006 
Xiantao Li  University of Minnesota  8/3/2004  8/31/2005 
Chun Liu  Pennsylvania State University  9/1/2004  6/30/2005 
Hailiang Liu  Iowa State University  1/1/2005  6/30/2005 
Xin Liu  University of California  Davis  6/22/2005  7/1/2005 
Yuanjin Liu  Wayne State University  6/21/2005  7/2/2005 
Deborah F. Lockhart  National Science Foundation  6/17/2005  6/19/2005 
David Love  Purdue University  6/25/2005  7/1/2005 
Steven Low  California Institute of Technology  6/26/2005  7/1/2005 
Tom Luo  University of Minnesota  6/26/2005  7/1/2005 
Mitchell Luskin  University of Minnesota  9/1/2004  6/30/2005 
Dionisios Margetis  Massachusetts Institute of Technology  6/7/2005  6/12/2005 
Karsten Matthies  Freie University Berlin  5/1/2005  6/15/2005 
David Mclaughlin  New York University  6/16/2005  6/18/2005 
Kevin W. Mclaughlin  University of Wisconsin  River Falls  6/7/2005  6/11/2005 
Sean P. Meyn  University of Illinois  UrbanaChampaign  6/21/2005  6/29/2005 
Wei Mo  Iowa State University  6/21/2005  7/1/2005 
Eytan Modiano  Massachusetts Institute of Technology  6/26/2005  7/1/2005 
Bagisa Mukherjee  Penn State Worthington Scranton  5/8/2005  6/9/2005 
Arnie Neidhardt  Telcordia Technologies  6/21/2005  7/1/2005 
Mahdi Nezafat  University of Minnesota  6/22/2005  7/1/2005 
Barbara Niethammer  Humboldt Universität zu Berlin  6/2/2005  6/11/2005 
Hans Christian Oettinger  ETHZ  6/7/2005  6/11/2005 
MiaoJung Yvonne Ou  University of Central Florida  6/7/2005  6/12/2005 
Peter Philip  University of Minnesota  8/22/2004  8/31/2006 
Harald Pleiner  Max Planck Institute for Polymer Research  5/10/2005  6/18/2005 
Vincent Poor  Princeton University  6/21/2005  7/1/2005 
Lea Popovic  University of Minnesota  9/2/2003  8/31/2005 
Alexandre Proutiere  France Telecom  6/21/2005  7/2/2005 
Tiezheng Qian  Hong Kong University of Science and Technology  6/7/2005  6/12/2005 
Leela Rakesh  CMU  6/7/2005  6/12/2005 
Weiqing Ren  Princeton University  6/7/2005  6/12/2005 
William Rundell  National Science Foundation  6/16/2005  6/18/2005 
Rolf Ryham  Pennsylvania State University  9/1/2004  6/30/2005 
Tathagata Samanta  Florida Institute of Technology  6/21/2005  7/2/2005 
Vittorio Sansalone  Italian Agency for New Technologies, Energy and the Environment  5/25/2005  6/12/2005 
Chekad Sarami  Fayetteville State University  6/21/2005  7/1/2005 
Arnd Scheel  University of Minnesota  7/15/2004  8/31/2006 
Christian Scheideler  Johns Hopkins University  6/26/2005  7/2/2005 
George R Sell  University of Minnesota  9/1/2004  6/30/2005 
James P. Sethna  Cornell University  5/30/2005  6/12/2005 
Vivek Shenoy  Brown University  6/8/2005  6/11/2005 
TienTsan Shieh  Indiana University  9/1/2004  6/30/2005 
ShagiDi Shih  University of Wyoming  5/1/2005  7/2/2005 
Ness Shroff  Purdue University  6/26/2005  7/1/2005 
Rahul Sinha  Illinois Institute of Technology  6/21/2005  7/1/2005 
Ioana Sirbu  Western Illinois University  6/7/2005  6/12/2005 
Peter Smereka  University of Michigan  5/30/2005  6/12/2005 
Valery P. Smyshlyaev  University of BathUK  4/10/2005  6/16/2005 
Qingshuo Song  Wayne State University  6/22/2005  7/1/2005 
Kevin William Sowerby  University of Auckland  6/21/2005  7/2/2005 
Daniel Spirn  University of Minnesota  9/1/2004  6/30/2005 
Peter J. Sternberg  Indiana University  8/15/2004  6/15/2005 
Vladimir Sverak  University of Minnesota  9/1/2004  6/30/2005 
Jun Tan  Motorola, Inc.  6/22/2005  7/1/2005 
Choon Yik Tang  Honeywell  6/26/2005  7/1/2005 
Alain B. Tchagang  University of Minnesota  6/22/2005  7/1/2005 
Luciano Teresi  Università degli Studi Roma Tre  4/10/2005  6/12/2005 
Florian Theil  University of Warwick  4/4/2005  6/11/2005 
Lev Truskinovsky  Ecole Polytechnique, Palaiseau  6/1/2005  6/11/2005 
Igor Tsukerman  University of Akron  6/7/2005  6/11/2005 
Gabriel Turinici  CERMICS  5/22/2005  6/10/2005 
Eric van den Berg  Telcordia Technologies  6/26/2005  7/1/2005 
Erik van der Giessen  University of Groningen  6/7/2005  6/10/2005 
Sriram Vishwanath  University of Texas  Austin  6/21/2005  7/1/2005 
Pascal Olivier Vontobel  ETH  Zurich  6/21/2005  7/2/2005 
Fan Wang  Motorola, Inc.  6/21/2005  7/1/2005 
Qi Wang  Florida State University  6/8/2005  6/12/2005 
Xiaodong Wang  Columbia University  6/26/2005  7/1/2005 
Zhengdao Wang  Iowa State University  6/22/2005  7/1/2005 
Wing Shing Wong  Chinese University of Hong Kong  6/26/2005  7/1/2005 
Doug Wright  University of Minnesota  2/15/2005  8/31/2005 
Dapeng Wu  University of Florida  6/27/2005  7/2/2005 
Baisheng Yan  Michigan State University  9/1/2004  6/15/2005 
Gregory E. Yawson  Lawrence Technological University  6/7/2005  6/11/2005 
Yunjung Yi  Honeywell  6/26/2005  7/1/2005 
George Yin  Wayne State University  6/21/2005  7/1/2005 
Aaron Nung Kwan Yip  Purdue University  1/16/2005  6/30/2005 
Emmanuel Yomba  University of Ngaoundéré  10/6/2004  8/31/2005 
Hossein Zare  University of Minnesota  6/22/2005  7/1/2005 
Ofer Zeitouni  University of Minnesota  6/26/2005  7/1/2005 
Junshan Zhang  Arizona State University  6/21/2005  6/25/2005 
Lisa Zhang  Lucent Technologies  6/22/2005  6/24/2005 
Qian Zhang  University of Wisconsin  Madison  6/21/2005  7/2/2005 
Qing Zhang  University of Georgia  6/26/2005  7/2/2005 
Hong Zhou  Naval Postgraduate School  6/8/2005  6/11/2005 
Johannes Zimmer  MaxPlanckInstitute for Math in the Sciences  5/29/2005  6/12/2005 