Results 11 - 20 of 5,558

Bayesian inference on phylogeny and its impact on evolutionary biology.

by John P Huelsenbeck , Fredrik Ronquist , Rasmus Nielsen , Jonathan P Bollback - Science , 2001
"... 1 As a discipline, phylogenetics is becoming transformed by a flood of molecular data. These data allow broad questions to be asked about the history of life, but also present difficult statistical and computational problems. Bayesian inference of phylogeny brings a new perspective to a number of o ..."
Abstract - Cited by 235 (10 self) - Add to MetaCart
)]. MCMC has revolutionized Bayesian inference, with recent applications to Bayesian phylogenetic inference (1-3) as well as many other problems in evolutionary biology (5-7). The basic idea is to construct a Markov chain that has as its state space the parameters of the statistical model and a stationary

Real-time visual tracking of complex structures

by Tom Drummond, Roberto Cipolla - IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE , 2002
"... This paper presents a novel framework for three-dimensional model-based tracking. Graphical rendering technology is combined with constrained active contour tracking to create a robust wire-frame tracking system. It operates in real time at video frame rate (25 Hz) on standard hardware. It is based ..."
Abstract - Cited by 226 (7 self) - Add to MetaCart
. It is based on an internal CAD model of the object to be tracked which is rendered using a binary space partition tree to perform hidden line removal. The visible edge features are thus identified online at each frame and correspondences are found in the video feed. A Lie group formalism is used to cast

A Numerical Method for the Study of the Circulation of the World Ocean

by Kirk Bryan - JOURNAL OF COMPUTATIONAL PHYSICS 135, 154–169 (1997) , 1997
"... A model is presented for studying ocean circulation problems taking into account the complicated outline and bottom topography of the World Ocean. To obtain an efficient scheme for the study of low-frequency, large-scale current systems, surface gravity-inertial waves are filtered out by the "r ..."
Abstract - Cited by 211 (2 self) - Add to MetaCart
;rigid-lid" approximation. To resolve special features of the ocean circulation, such as the Equatorial Undercurrent, the numerical model allows for a variable spacing in either the zonal or meridional direction. The model is designed to be as consistent as possible with the continuous equations with respect to energy

An O(ND) Difference Algorithm and Its Variations

by Eugene W. Myers - Algorithmica , 1986
"... The problems of finding a longest common subsequence of two sequences A and B and a shortest edit script for transforming A into B have long been known to be dual problems. In this paper, they are shown to be equivalent to finding a shortest/longest path in an edit graph. Using this perspective, a s ..."
Abstract - Cited by 212 (4 self) - Add to MetaCart
to have O(N +D expected-time performance under a basic stochastic model. A refinement of the algorithm requires only O(N) space, and the use of suffix trees leads to an O(NlgN +D ) time variation.

Beam tracing polygonal objects

by Paul S Heckbert , Pat Hanrahan - In Computer Graphics (Proceedings of ACM SIGGRAPH , 1984
"... Abstract Ray tracing has produced some of the most realistic computer generated pictures to date. They contain surface texturing, local shading, shadows, reflections and refractions. The major disadvantage of ray tracing results from its point-sampling approach. Because calculation proceeds ab init ..."
Abstract - Cited by 214 (1 self) - Add to MetaCart
coherence of polygonal environments by combining features of both image and object space hidden surface algorithms. Instead of tracing infinitesimally thin rays of light, we sweep areas through a scene to form "beams." This technique works particularly well for polygonal models since for this case

Parameterized Modeling and Recognition of Activities

by Yaser Yacoob, Michael Black - Computer Vision and Image Understanding , 1999
"... this paper we consider a class of human activities--atomic activities--which can be represented as a set of measurements over a finite temporal window (e.g., the motion of human body parts during a walking cycle) and which has a relatively small space of variations in performance. A new approach for ..."
Abstract - Cited by 203 (7 self) - Add to MetaCart
their representation using principal component analysis. The recognition of variants of modeled activities is achieved by searching the space of admissible parameterized transformations that these activities can undergo. This formulation iteratively refines the recognition of the class to which the observed activity

On the Sensitivity of the Hough Transform for Object Recognition

by W. Eric L. Grimson, Daniel P. Huttenlocher - IEEE TRANS. ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE , 1990
"... Object recognition from sensory data involves, in part, determining the pose of a model with respect to a scene. A common method for finding an object's pose is the generalized Hough transform, which accumulates evidence for possible coordinate transformations in a parameter space whose axes ar ..."
Abstract - Cited by 128 (5 self) - Add to MetaCart
Object recognition from sensory data involves, in part, determining the pose of a model with respect to a scene. A common method for finding an object's pose is the generalized Hough transform, which accumulates evidence for possible coordinate transformations in a parameter space whose axes

Temporal sequence learning and data reduction for anomaly detection

by Terran Lane, Carla E. Brodley - ACM TRANSACTIONS ON INFORMATION SYSTEMS SECURITY , 1999
"... The anomaly detection problem can be formulated as one of learning to characterize the behaviors of an individual, system, or network in terms of temporal sequences of discrete data. We present an approach to this problem based on instance based learning (IBL) techniques. To cast the anomaly detecti ..."
Abstract - Cited by 191 (6 self) - Add to MetaCart
detection task in an IBL framework, we employ an approach that transforms temporal sequences of discrete, unordered observations into a metric space via a similarity measure that encodes intra-attribute dependencies. Classification boundaries are selected from an a posteriori characterization of the valid

Progressive Simplicial Complexes

by Jovan Popovic, Hugues Hoppe , 1997
"... In this paper, we introduce the progressive simplicial complex (PSC) representation, a new format for storing and transmitting triangulated geometric models. Like the earlier progressive mesh (PM) representation, it captures a given model as a coarse base model together with a sequence of refinement ..."
Abstract - Cited by 169 (2 self) - Add to MetaCart
of refinement transformations that progressively recover detail. The PSC representation makes use of a more general refinement transformation, allowing the given model to be an arbitrary triangulation (e.g. any dimension, non-orientable, non-manifold, non-regular), and the base model to always consist of a

Partial and approximate symmetry detection for 3D geometry

by Niloy J. Mitra, Leonidas J. Guibas, Mark Pauly - ACM TRANSACTIONS ON GRAPHICS , 2006
"... “Symmetry is a complexity-reducing concept [...]; seek it everywhere.” Alan J. Perlis Many natural and man-made objects exhibit significant symmetries or contain repeated substructures. This paper presents a new algorithm that processes geometric models and efficiently discovers and extracts a com ..."
Abstract - Cited by 176 (26 self) - Add to MetaCart
compact representation of their Euclidean symmetries. These symmetries can be partial, approximate, or both. The method is based on matching simple local shape signatures in pairs and using these matches to accumulate evidence for symmetries in an appropriate transformation space. A clustering stage
Results 11 - 20 of 5,558