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30
A tutorial on support vector machines for pattern recognition
 Data Mining and Knowledge Discovery
, 1998
"... The tutorial starts with an overview of the concepts of VC dimension and structural risk minimization. We then describe linear Support Vector Machines (SVMs) for separable and nonseparable data, working through a nontrivial example in detail. We describe a mechanical analogy, and discuss when SV ..."
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Cited by 2356 (11 self)
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The tutorial starts with an overview of the concepts of VC dimension and structural risk minimization. We then describe linear Support Vector Machines (SVMs) for separable and nonseparable data, working through a nontrivial example in detail. We describe a mechanical analogy, and discuss when SVM solutions are unique and when they are global. We describe how support vector training can be practically implemented, and discuss in detail the kernel mapping technique which is used to construct SVM solutions which are nonlinear in the data. We show how Support Vector machines can have very large (even infinite) VC dimension by computing the VC dimension for homogeneous polynomial and Gaussian radial basis function kernels. While very high VC dimension would normally bode ill for generalization performance, and while at present there exists no theory which shows that good generalization performance is guaranteed for SVMs, there are several arguments which support the observed high accuracy of SVMs, which we review. Results of some experiments which were inspired by these arguments are also presented. We give numerous examples and proofs of most of the key theorems. There is new material, and I hope that the reader will find that even old material is cast in a fresh light.
ObjectCentered Surface Reconstruction: Combining MultiImage Stereo and Shading
 International Journal of Computer Vision
, 1995
"... Our goal is to reconstruct both the shape and reflectance properties of surfaces from multiple images. We argue that an objectcentered representation is most appropriate for this purpose because it naturally accommodates multiple sources of data, multiple images (including motion sequences of a rig ..."
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Cited by 121 (19 self)
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Our goal is to reconstruct both the shape and reflectance properties of surfaces from multiple images. We argue that an objectcentered representation is most appropriate for this purpose because it naturally accommodates multiple sources of data, multiple images (including motion sequences of a rigid object), and selfocclusions. We then present a specific objectcentered reconstruction method and its implementation. The method begins with an initial estimate of surface shape provided, for example, by triangulating the result of conventional stereo. The surface shape and reflectance properties are then iteratively adjusted to minimize an objective function that combines information from multiple input images. The objective function is a weighted sum of stereo, shading, and smoothness components, where the weight varies over the surface. For example, the stereo component is weighted more strongly where the surface projects onto highly textured areas in the images, and less strongly othe...
Predictive ApplicationPerformance Modeling in a Computational Grid Environment
, 1999
"... This paper describes and evaluates the application of three local learning algorithms  nearestneighbor, weightedaverage, and locallyweighted polynomial regression  for the prediction of runspecific resourceusage on the basis of runtime input parameters supplied to tools. A twolevel knowl ..."
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Cited by 62 (12 self)
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This paper describes and evaluates the application of three local learning algorithms  nearestneighbor, weightedaverage, and locallyweighted polynomial regression  for the prediction of runspecific resourceusage on the basis of runtime input parameters supplied to tools. A twolevel knowledge base allows the learning algorithms to track shortterm fluctuations in the performance of computing systems, and the use of instance editing techniques improves the scalability of the performancemodeling system. The learning algorithms assist PUNCH, a networkcomputing system at Purdue University, in emulating an ideal user in terms of its resource management and usage policies. 1. Introduction It is now recognized that the heterogeneous nature of the networkcomputing environment cannot be effectively exploited without some form of adaptive or demanddriven resource management (e.g., [10, 11, 12, 14, 18, 27]). A demanddriven resource management system can be characterized by its a...
Frequency Analysis of Gradient Estimators in Volume Rendering
 IEEE Transactions on Visualization and Computer Graphics
, 1996
"... ..."
Speaker Independent AudioVisual Database For Bimodal ASR
 Proc. Europ. Tut. Work. AudioVisual Speech Proc., Rhodes
, 1997
"... This paper describes the audiovisual database collected at AT&T Labs#Research for the study of bimodal speech recognition. To date, this database consists of twomultiple speaker parts, namely isolated confusable words and connected letters, thus allowing the study of some popular and relatively ..."
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Cited by 26 (3 self)
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This paper describes the audiovisual database collected at AT&T Labs#Research for the study of bimodal speech recognition. To date, this database consists of twomultiple speaker parts, namely isolated confusable words and connected letters, thus allowing the study of some popular and relatively simple speaker independent audiovisual recognition tasks. In addition, a single speaker connected digits database is collected to facilitate speedy development and testing of various algorithms. Intentionally,no lip markings are used on the subjects during data collection. Development of robust and speaker independent algorithms for mouth location and lip contour extraction is thus necessary in order to obtain informative features about visual speech #visual front end#. We describe our approach to this problem, and we report our automatic speechreading and audiovisual speech recognition results on the single speaker connected digits task. 1.
Using 3Dimensional Meshes To Combine ImageBased and GeometryBased Constraints
 IN EUROPEAN CONFERENCE ON COMPUTER VISION
, 1994
"... A unified framework for 3D shape reconstruction allows us to combine imagebased and geometrybased information sources. The image information is akin to stereo and shapefromshading, while the geometric information may be provided in the form of 3D points, 3D features or 2D silhouettes. A form ..."
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Cited by 24 (4 self)
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A unified framework for 3D shape reconstruction allows us to combine imagebased and geometrybased information sources. The image information is akin to stereo and shapefromshading, while the geometric information may be provided in the form of 3D points, 3D features or 2D silhouettes. A formal integration framework is critical in recovering complicated surfaces because the information from a single source is often insufficient to provide a unique answer. Our approach to shape recovery is to deform a generic objectcentered 3D representation of the surface so as to minimize an objective function. This objective function is a weighted sum of the contributions of the various information sources. We describe these various terms individually, our weighting scheme, and our optimization method. Finally, we present results on anumber of difficult images of real scenes for which a single source of information would have proved insufficient.
From Regular Images to Animated Heads: A Least Squares Approach
 in European Conference on Computer Vision
, 1998
"... We show that we can effectively fit arbitrarily complex animation models to noisy image data. Our approach is based on leastsquares adjustment using of a set of progressively finer control triangulations and takes advantage of three complementary sources of information: stereo data, silhouette edge ..."
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Cited by 23 (8 self)
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We show that we can effectively fit arbitrarily complex animation models to noisy image data. Our approach is based on leastsquares adjustment using of a set of progressively finer control triangulations and takes advantage of three complementary sources of information: stereo data, silhouette edges and 2D feature points.
Analysis and Computation of Immersed Boundaries, With Application to Pulp Fibres
 University of British Columbia
, 1997
"... We accept this thesis as conforming ..."
A Projective Framework for Structure and Motion Recovery from Two Views of a Piecewise Planar Scene
, 2000
"... In this paper, we consider the problem of finding an optimal reconstruction from two views of a piecewise planar scene. We consider the general case of uncalibrated cameras, hence place us in a projectlye framework. In this case, there is no meaningful metric information about the object space that ..."
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Cited by 7 (1 self)
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In this paper, we consider the problem of finding an optimal reconstruction from two views of a piecewise planar scene. We consider the general case of uncalibrated cameras, hence place us in a projectlye framework. In this case, there is no meaningful metric information about the object space that could be used to define optimization criteria. Taking into account that the images are then the only spaces where an optimization process makes sense, there is a need at each step of the reconstruction process, from the detection of planar structures to motion estimation and actual 3D reconstruction, of a consistent image level representation of geometric 3D structures. In our case, we need to represent camera motion and 3D points that are subject to coplanarity constraints. It is well known that camera motion between two views can be represented on the image level via the epipolar geometry (fundamental matrix). Coplanarity constraints can be expressed via a collection of 2D homographies. Unfortunately, these algebraic entities are overparameterized in the sense that the 2D homographies must in addition obey constraints imposed by the epipolar geometry. We are thus looking for a minimal and consistent representation of motion (epipolar geometry) and structure (points+homographies) that in addition should be easy to use for minimizing reprojection error in a bundle adjustment manner. In this paper, we propose such a representation and use it to devise fast and accurate estimation methods for each step of the reconstruction process, including image point matching, plane detection and optimal triangulation of planes and points on planes. We make extensive use of the quasilinear optimization principle. A great number of experimental results show that the new methods give sup...
A Mean Field Stochastic Theory for SpeciesRich Assembled Communities
"... A dynamical model of an ecological community is analyzed within a "meanfield approximation" in which one of the species interacts with the combination of all of the other species in the community. Within this approximation the model may be formulated as a master equation describing a one ..."
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Cited by 7 (2 self)
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A dynamical model of an ecological community is analyzed within a "meanfield approximation" in which one of the species interacts with the combination of all of the other species in the community. Within this approximation the model may be formulated as a master equation describing a onestep stochastic process. The stationary distribution is obtained in closed form and is shown to reduce to a logseries or lognormal distribution, depending on the values that the parameters describing the model take on. A hyperbolic relationship between the connectance of the matrix of interspecies interactions and the average number of species, exists for a range of parameter values. The time evolution of the model at short and intermediate times is analyzed using van Kampen's approximation, which is valid when the number of individuals in the community is large. Good agreement with numerical simulations is found. The large time behavior, and the approach to the stationary state, is obtained by solvi...