The traveling salesman problem, or TSP for short, is easy to state: given a number of 'cities' along with the cost of travel between each pair of them, find the cheapest way of visiting all the cities and returning to your starting point. The simplicity of the statement is deceptive - the TSP is one of the most intensely studied problems in comp...
Creator:
Cook, William (Georgia Institute of Technology)
Created:
2002-10-16
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
The first completely sequenced genome, the virus Lambda at 50,000 nucleotides, was sequenced via the shotgun method by Sanger and coworkers at Cambridge in 1981. The shotgun method consists of randomly sampling and determining 500-700 nucleotide 'reads' and then assembling them to reconstruct the sampled sequence. It was long believed that this ...
Creator:
Myers, Gene (University of California, Berkeley)
Created:
2003-05-06
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
The Human Genome Project has catalyzed the emergence of a new approach to biology termed systems biology. Systems biology analyzes all the interrelationships of the elements in a biological system, rather than studying them one at a time, as has been the modus operandi in biology for the past 30 years. This systems approach has also emerged in t...
Creator:
Hood, Leroy E. (Institute for Systems Biology)
Created:
2003-09-15
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Throughout his life, either as participant, support individual, or involved spectator, the speaker has been involved in some aspect of drag racing. As such he has witnessed the birth and growth of many myths concerning dragster speed and acceleration. In this talk the speaker uses his mathematical training to identify rather elementary mathemati...
Creator:
Tapia, Richard (Rice University)
Created:
2003-11-20
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Secrets of the heart include the changes in the circulation occurring at birth, the muscular fiber architecture of the cardiac ventricles, the collagen fiber architecture of the heart valves, the electrical activity that coordinates and controls the heartbeat, and the vortex flow patterns of blood in the cardiac chambers. In this lecture, mathem...
Creator:
Peskin, Charles S. (New York University)
Created:
2003-06-05
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Frustrated by difficulties in explaining seemingly aberrant financial market behavior using contemporary methods of financial economics, a new school of behavioral finance has arisen that mixes psychology and economics. Despite the superficial appeal of this multi-disciplinary approach, this talk critiques behavioral finance by using the analyti...
Creator:
Ross, Stephen (Massachusetts Institute of Technology)
Created:
2004-03-30
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Is there something remarkable about the great precision and subtlety of the mathematical laws that appear to govern, in full detail, the behavior of the physical universe? Or do the perceived laws of physics merely reflect our own attempts to make some order out of the complication of observed physical action? Are all our own actions governed co...
Creator:
Penrose, Roger FRS (University of Oxford)
Created:
2004-10-05
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
What caused hundreds of Japanese children to fall into seizures while watching an episode of the cartoon show Pokemon? Why do women roommates sometimes find that their menstrual periods occur in sync?The tendency to synchronize is one of the most mysterious and pervasive drives in all of nature. Every night along the tidal rivers of Malaysia, th...
Creator:
Strogatz, Steven H. (Cornell University)
Created:
2004-01-07
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
The rise in divorce rates in developed countries, including the US, is a widespread, important and poorly understood phenomenon. The benefits of happy marriages are clear. Laboratory methods have been developed to observe interactions of couples to identify patterns that are predictive of divorce or whether the couple will be unhappily married.M...
Creator:
Murray, James D. (University of Washington)
Created:
2004-11-18
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
3D optical elements modulate light through interaction with an entirevolume of variable refractive index (as opposed to a sequence of surfacesused in traditional optics.) One commonly used form of 3D optics isgradient-index (GRIN) where the modulation is base-band. Instead, we haveemphasized use of modulations on a spatial carrier (grating.) We ...
Creator:
Barbastathis, George (Massachusetts Institute of Technology)
Created:
2005-11-11
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Adaptive sampling, also called 'Active Learning', uses informationgleaned from previous measurements (e.g., feedback) to guide and focusthe sampling process. Theoretical and experimental results have shownthat adaptive sampling can dramatically outperform conventionalnon-adaptive sampling schemes. I will review some of the mostencouraging theore...
Creator:
Nowak, Robert (University of Wisconsin, Madison)
Created:
2005-12-08
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We propose a new approach to classical detection problem of discriminationof a true signal from an interferent signal. We show that the detectionperformance, as quantified by the receiver operating curve (ROC), can besubstantially improved when the signal is represented by a multi-componentdata set that is actively manipulated by a shaped probin...
Creator:
Levis, Robert J. (Temple University)
Created:
2005-11-09
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We present a direct imaging algorithm for both the location and geometry of extended targets. Our algorithm is based on a physical factorization of the response matrix of an active array. A resolution and noise level based thresholding is used for regularization. Our algorithm is extremely simple and efficient since no forward solver or iteratio...
Creator:
Zhao, Hongkai (University of California, Irvine)
Created:
2005-10-20
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
in collaboration with Gunther Uhlmann and Hart SmithIn reflection seismology one places sources and receivers on theEarth's surface. The source generates waves in the subsurface that arereflected where the medium properties vary discontinuously; thesereflections are observed in all the receivers. The data thus obtainedare commonly modeled by a s...
Creator:
De Hoop, Maarten (Purdue University)
Created:
2005-10-21
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Joint work with Doug Oldenburg.Image appraisal in geophysical inverse problem can provide insight into theresolving capability and uncertainty of estimates. Although a rigorous approachto solve nonlinear appraisal analysis is still lacking but several methods havebeen proposed in the past such as linearized Backus-Gilbert analysis, funnelfunctio...
Creator:
Routh, Partha S. (Boise State University)
Created:
2005-10-18
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
I will present a qualitative, model free theory forimaging in clutter with coherent interferometry.Coherent interferometry is a smoothed form of Kirchhoffor travel time migration that is implemented adaptivelyin order to optimize the bias-variance tradeoff in theimage quality, as it is being formed. I will show theresults of numerical simulation...
Creator:
Papanicolaou, George C. (Stanford University)
Created:
2005-10-17
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Classical detection theory for sensing relies on fixed targetillumination and independent identically distributed noise for target andclutter characterization. Unfortunately in many cases such as sensing andcommunications in urban or atmospheric scenarios, we encounter much morecomplex clutter and target conditions due to scattering from multipl...
Creator:
Bonneau, Bob (US Air Force Research Laboratory)
Created:
2005-10-17
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
ATR Theory, especially the performance prediction aspects, are fundamentalto integrated sensing and processing. Offline and online prediction andfeedback are essential processing tools for assessing which sensing actionswill likely provide the most information. I'll discuss the overlap betweenActive Vision, ATR Theory, and ISP and highlight rele...
Creator:
Arnold, D. Gregory
Created:
2005-12-05
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Imaging sensors, hardware, and algorithms are under increasingpressure to accommodate ever larger and higher-dimensional data sets;ever faster capture, sampling, and processing rates; ever lower powerconsumption; communication over ever more difficult channels; andradically new sensing modalities. Fortunately, over the past fewdecades, there has...
Creator:
Baraniuk, Richard G. (Rice University)
Created:
2005-11-07
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Optical spectroscopy offers an ideal area for testing and development of compressive sensing systems. Measurement costs can be high, generalized sampling strategies are easily implemented and prior information and feature specific tasks are common. This talk describes experimental and conceptual studies of compressive spectroscopy in the DISP gr...
Creator:
Brady, David J. (Duke University)
Created:
2005-12-07
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Conventional wisdom and common practice in acquisition andreconstruction of images or signals from frequency data follows thebasicprinciple of the Nyquist density sampling theory. This principlestates that to reconstruct an image/signal, the number of Fouriersamples weneed to acquire must match the desired resolution of the image/signal, e.g.the...
Creator:
Candès, Emmanuel J. (California Institute of Technology)
Created:
2005-12-05
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Computers crash, hang, succumb to viruses, run buggy programs, and harbor spyware. By contrast, mathematics is free of all imperfection. Why are imperfect computational devices so vital for the future of mathematics?
Creator:
Hales, Thomas (University of Pittsburgh)
Created:
2005-03-30
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
In this talk I will first show how to use simpleand classical results from distance geometry toaddress the problem of sensor localization underphysical constraints.Then I will move into presenting some recent resultsin video processing that I wish could be done at the sensorlevel. For example, I will show techniques thatreduce the video data to ...
Creator:
Sapiro, Guillermo R. (University of Minnesota, Twin Cities)
Created:
2005-12-09
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
An approximation of the solution to a hyperbolic equation with a damping term is introduced. It is built as the composition of Fourier integral operators (FIO). We prove the convergence of this approximation in the sense of Sobolev norms as well as for the wavefront set of the solution. We apply the introduced method tonumerically image seismic ...
Creator:
Le Rousseau, Jerome (Aix-Marseille Université, Université de Provence))
Created:
2005-10-20
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Data fusion and multi-cue data matching are fundamental tasks arisingin a variety of systems that process large amounts of data. Thesetasks often rely on dimensionality reduction techniques thattraditionally follow a data acquisition/reprocessing phase.In this talk, I will describe a powerful framework based on diffusionsthat can be used in orde...
Creator:
Lafon, Stephane (Google Inc.)
Created:
2005-12-06
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Dimensionality reduction methods have played a central role in exploration of parsimonious structural models, complexity regularizationin inverse problems, and data compression. Examples are PCA, Laplacian eigenmaps, ISOMAP, and matching pursuits which attempt to fit asubspace to the data. For integrated sensing and processing (ISP) systems dime...
Creator:
Hero, Alfred O. III (University of Michigan)
Created:
2005-12-08
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
The human brain contains about 100 billion neurons, each making about 1000 synaptic connections with other neurons. This huge dynamical system communicates with itself and its environment via electrical impulses called spikes. How is incoming information turned into spikes, and how do spikes create decisions and behaviors? I will show how mathem...
Creator:
Holmes, Philip J. (Princeton University)
Created:
2005-12-08
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
It has been noted that many realistic networks have a power law degree distributionand exhibit the small world phenomenon. We consider graph drawing methods that takeadvantage of recent developments in the modeling of such networks.Our main approach is to partition the edge set of a graph into 'local' edgesand 'global' edges, and to use a force-...
Creator:
Chung Graham, Fan
Created:
2005-11-08
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Complex systems are ubiquitous in mathematics, biology,engineering, and physics, and the past ten years have witnessed an exponentialincrease in the literature associated such systems. A shared conceptualframework is becoming apparent among challenges as seemingly different as thefollowing: the search by mathematicians for exact high-order trigo...
Creator:
Sidles, John A. (University of Washington)
Created:
2005-11-09
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Detecting pathology using the 'stiffness' of the tissue is more that 2000 years old. Even today it is common for surgeons to feel lesions during surgery that have been missed by advanced imaging methods. Palpation is subjective and limited to individual experience and to the accessibility of the tissue region to touch. It appears that a means of...
Creator:
Greenleaf, James F. (Mayo Clinic)
Created:
2005-10-17
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Traditional optical design typically exploits only limitedprior knowledge of the object space to be imaged (e.g., resolution, field of view, nominal range, etc.) It is possibleto include stronger object space constraints (e.g., specificobjects of interest, operational SNR, background characteristics, etc.) into the optical design and thus genera...
Creator:
Neifeld, Mark A. (University of Arizona)
Created:
2005-11-11
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
The talk will be divided in two parts. The first part will be devoted to diffraction tomography based on the scalar wave equationto obtain images of the refractive-index distribution of an object embedded in a homogeneous medium, with emphasis on experimentalverifications of this technique in applications using light or ultrasound. The second pa...
Creator:
Stamnes, Jakob J. (University of Bergen)
Created:
2005-10-19
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
One can trade off complexity in imaging system hardware and strictsystem tolerances for complexity in post-detection data processing.We describe an extreme example in this trade-off space: a coherentimaging approach that eliminates the imaging system hardware entirely(except for the detector array), relying on a phase retrievalalgorithm to form ...
Creator:
Fienup, James R. (University of Rochester)
Created:
2005-12-07
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Sensor networking is an emerging technology that promises anunprecedented ability to monitor the physical world via a spatiallydistributed network of small and inexpensive wireless sensor nodes.The nodes can measure the physical environment with a wide variety ofsensors, including acoustic, seismic, thermal, and infrared. While thepractically un...
Creator:
Nowak, Robert
Created:
2005-11-10
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Solving the phase retrieval problem, i.e. reconstructing a compact, multidimensional function from the modulus of its Fourier transform, has applications in astronomy, x-ray diffraction, optical wave-front sensing, and other areas of physics and engineering. To solve such problems, one must have constraints on the function in order to have a cha...
Creator:
Fienup, James R. (University of Rochester)
Created:
2005-11-09
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
An important problem (perhaps the most important problem to theDepartment of Defense) in modern remote sensing is that of correctlyidentifying potential targets at great distances and in all kind ofweather. Because of their ability to see through clouds and in theabsence of ambient radiation, active radar systems are usuallyrequired for this tas...
Creator:
Borden, Brett (Naval Postgraduate School)
Created:
2005-10-17
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We present recent work on imaging and reconstruction of objectsfrom radar backscatter measurements taken over wide aspect angles.Radar backscattering is a function of several variables, includinglocation, (complex-valued) amplitude, polarization, and the aspect(azimuth and elevation) of the interrogating sensor. Thishigh-dimensional data is ofte...
Creator:
Moses, Randy (The Ohio State University)
Created:
2005-10-18
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We consider a very general inverse problem on directed graphs.Surprisingly, this problem can actually be solved, explicitly, in a largeclass of examples. I will describe the construction of these examples, aswell as the method used to produce the inversion formulas. This is jointwork with F. Alberto Grunbaum.
Creator:
Matusevich, Laura Felicia (Texas A & M University)
Created:
2005-11-10
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Interbed multiples form a class of multiples in seismic data characterized by the property that all reflection points lie in thesubsurface. This sets them apart from surface multiples, which have at least one reflection point at the surface of the earth.For surface multiples there is a well established procedure to predict them from the data, i....
Creator:
Ten Kroode, Fons (The Shell Group)
Created:
2005-10-20
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We consider imaging the earth's topography using synthetic apertureRADAR (SAR), as well as real aperture RADAR (RAR). We use a simplescalar wave model for the radio waves. Instead of the common approachof singly-scattered waves, we consider the situation where a reflecting'wall' is located in the vicinity of the region of interest (ROI). Wewill ...
Creator:
Nolan, Clifford (University of Limerick)
Created:
2005-10-18
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Processing information at the sensor level can not only help reduce theamount of data acquired but also enhance the overall performance of thesystem. In this talk I will first present methods for shaping thethree-dimensional response of an optical system. Then I will discuss howto integrate tailored optical responses with digital postprocessinga...
Creator:
Piestun, Rafael (University of Colorado)
Created:
2005-12-07
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We consider the problem of determining earth properties fromseismic data, i.e. measurements with broadband acoustic wavesusing sources and receivers at the surface. For current dataprocessing methods this is considered as a partially linearizedinverse problem, where data is modelled by linearization about asmooth background medium, with a medium...
Creator:
Stolk, Chris (Universiteit Twente)
Created:
2005-10-19
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
We present some of our recent work on coherent image reconstruction.The primary application that has driven this work has been syntheticaperture radar, although we have extended our approach to othermodalities such as ultrasound imaging as well. One of the motivationsfor our work has been the increased interest in using reconstructedimages in au...
Creator:
Cetin, Mujdat (Massachusetts Institute of Technology)
Created:
2005-10-17
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Joint work with Abhijit Mahalanobis.The concept of Integrated Sensing and Processing (ISP) suggests that asensor should collect data in a manner that is consistent with the endobjective. Thus ISP seeks to minimize the collection of redundant data,reduce processing time and improve overall performance. We present acase study of ISP using a multi-...
Creator:
Muise, Robert (Lockheed Martin)
Created:
2005-12-05
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
COMP-I is a program under the DARPA MONTAGE program focusing on theconstruction of thin digital imaging systems. COMP-I uses opticalprefilters to encode the impulse response of multiple aperture imagingsystems. The COMP-I program is near the completion of phase Idevelopment and has produced both visible and IR imaging systems basedon focal plane...
Creator:
Brady, David J. (Duke University)
Created:
2005-11-07
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
The representation of color for perception differs from therepresentation for displays. We consider the map from (r,g,b)-space to (Intensity, hue, saturation)-space, and show how this non-linear space is useful for sensingdevices.
Creator:
Zucker, Steven W. (Yale University)
Created:
2005-12-09
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.
Joint work with Florence Delprat-Jannaud. Geophysicists are quite aware of the important troubles that can be met whenthe seismic data are contaminated by multiple reflections. The situationthey have in mind is the one where multiple reflections are generated byisolated interfaces associated with high impedance contrasts. We here studya more ins...
Creator:
Lailly, Patrick (Institut Français du Pétrole)
Created:
2005-10-21
Contributed By:
University of Minnesota, Institute for Mathematics and its Applications.