Results 1 - 10 of 12,102

Segmentation of brain MR images through a hidden Markov random field model and the expectation-maximization algorithm

by Yongyue Zhang, Michael Brady, Stephen Smith - IEEE TRANSACTIONS ON MEDICAL. IMAGING , 2001
"... The finite mixture (FM) model is the most commonly used model for statistical segmentation of brain magnetic resonance (MR) images because of its simple mathematical form and the piecewise constant nature of ideal brain MR images. However, being a histogram-based model, the FM has an intrinsic limi ..."
Abstract - Cited by 639 (15 self) - Add to MetaCart
The finite mixture (FM) model is the most commonly used model for statistical segmentation of brain magnetic resonance (MR) images because of its simple mathematical form and the piecewise constant nature of ideal brain MR images. However, being a histogram-based model, the FM has an intrinsic

Free-form deformation of solid geometric models

by Thomas W. Sederberg, Scott R. Parry - IN PROC. SIGGRAPH 86 , 1986
"... A technique is presented for deforming solid geometric models in a free-form manner. The technique can be used with any solid modeling system, such as CSG or B-rep. It can deform surface primitives of any type or degree: planes, quadrics, parametric surface patches, or implicitly defined surfaces, f ..."
Abstract - Cited by 701 (1 self) - Add to MetaCart
, for example. The deformation can be applied either globally or locally. Local deformations can be imposed with any desired degree of derivative continuity. It is also possible to deform a solid model in such a way that its volume is preserved. The scheme is based on trivariate Bernstein polynomials

Climate and atmospheric history of the past 420,000 years from the Vostok ice core,

by J R Petit , J Jouzel , D Raynaud , N I Barkov , J.-M Barnola , I Basile , M Bender , J Chappellaz , M Davisk , G Delaygue , M Delmotte , V M Kotlyakov , M Legrand , V Y Lipenkov , C Lorius , L Pé , C Ritz , E Saltzmank , M Stievenard - Antarctica. Nature , 1999
"... Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial-interglacial cycles. The succession of changes through each climate cycle and termination was similar, and atmospheric and climate properties oscillated between stable bounds. Inte ..."
Abstract - Cited by 716 (15 self) - Add to MetaCart
temperature, and of atmospheric greenhousegas concentrations, with respect to global ice volume and Greenland air-temperature changes during glacial terminations. The ice record The data are shown in Figs 1, 2 and 3 (see Supplementary Information for the numerical data). They include the deuterium content

Measuring phase-synchrony in brain signals

by Eugenio Rodriguez, Jacques Martinerie, Francisco J. Varela - Hum. Brain Mapp , 1999
"... r r Abstract: This article presents, for the first time, a practical method for the direct quantification of frequency-specific synchronization (i.e., transient phase-locking) between two neuroelectric signals. The motivation for its development is to be able to examine the role of neural synchronie ..."
Abstract - Cited by 346 (6 self) - Add to MetaCart
that whereas long-scale effects do reflect cognitive processing, short-scale synchronies are likely to be due to volume conduction. We discuss ways to separate such conduction

Stochastic global optimization

by Anatoly Zhigljavsky , 2008
"... Stochastic global optimization methods are methods for solving a global optimization prob-lem incorporating probabilistic (stochastic) elements, either in the problem data (the objective function, the constraints, etc.), or in the algorithm itself, or in both. Global optimization is a very important ..."
Abstract - Cited by 289 (6 self) - Add to MetaCart
optimization we refer to the ‘Journal of Global Optimization ’ and two volumes of the ‘Handbook of Global Optimization ’ [1,2]. If the objective function is given as a ‘black box ’ computer code, the optimization problem is es-pecially difficult. Stochastic approaches can often deal with problems of this kind

Independent component analysis of electroencephalographic data

by Tzyy-ping Jung, Scott Makeig, Anthony J. Bell - Adv. Neural Inform. Process. Syst , 1996
"... The electroencephalogram (EEG) is a non-invasive measure of brain electrical activity recorded as changes in potential difference between points on the human scalp. Because of volume conduction through cerebrospinal fluid, skull and scalp, EEG data collected from any point on the scalp includes acti ..."
Abstract - Cited by 306 (61 self) - Add to MetaCart
The electroencephalogram (EEG) is a non-invasive measure of brain electrical activity recorded as changes in potential difference between points on the human scalp. Because of volume conduction through cerebrospinal fluid, skull and scalp, EEG data collected from any point on the scalp includes

BrainWeb: Online Interface to a 3D MRI Simulated Brain Database

by Chris A. Cocosco, Vasken Kollokian, Remi K.-S. Kwan, G. Bruce Pike, Alan C. Evans - NeuroImage , 1997
"... Introduction: The increased importance of automated computer techniques for anatomical brain mapping from MR images and quantitative brain image analysis methods leads to an increased need for validation and evaluation of the effect of image acquisition parameters on performance of these procedures ..."
Abstract - Cited by 283 (3 self) - Add to MetaCart
, online on WWW, a set of realistic simulated brain MR image volumes (Simulated Brain Database, SBD) that allows the above issues to be examined in a controlled, systematic way. Methods: The 3D simulated MR images are generated by varying specific imaging parameters and artifacts in an MRI simulator

A finite-volume, incompressible Navier–Stokes model for studies of the ocean on parallel computers.

by John Marshall , Alistair Adcroft , Chris Hill , Lev Perelman , Curt Heisey - J. Geophys. Res., , 1997
"... Abstract. The numerical implementation of an ocean model based on the incompressible Navier Stokes equations which is designed for studies of the ocean circulation on horizontal scales less than the depth of the ocean right up to global scale is described. A "pressure correction" method i ..."
Abstract - Cited by 293 (32 self) - Add to MetaCart
Abstract. The numerical implementation of an ocean model based on the incompressible Navier Stokes equations which is designed for studies of the ocean circulation on horizontal scales less than the depth of the ocean right up to global scale is described. A "pressure correction" method

A voxel-based morphometric study of ageing in 465 normal adult human brains.

by Catriona D Good , Ingrid S Johnsrude , John Ashburner , Richard N A Henson , Karl J Friston , Richard S J Frackowiak - NeuroImage , 2001
"... Voxel-based-morphometry (VBM) is a whole-brain, unbiased technique for characterizing regional cerebral volume and tissue concentration differences in structural magnetic resonance images. We describe an optimized method of VBM to examine the effects of age on grey and white matter and CSF in 465 n ..."
Abstract - Cited by 267 (2 self) - Add to MetaCart
Voxel-based-morphometry (VBM) is a whole-brain, unbiased technique for characterizing regional cerebral volume and tissue concentration differences in structural magnetic resonance images. We describe an optimized method of VBM to examine the effects of age on grey and white matter and CSF in 465

A three dimensional statistical analysis for CBF activation studies in human brain

by K. J. Worsley, A. C. Evans, S. Marrett, P. Neelin - Journal of Cerebral Blood Flow and Metabolism , 1992
"... Many studies of brain function with positron emission tomography (PET) involve the interpretation of a subtracted PET image, usually the difference between two images under baseline and stimulation conditions. The purpose of these studies is to see which areas of the brain are activated by the stimu ..."
Abstract - Cited by 250 (33 self) - Add to MetaCart
Many studies of brain function with positron emission tomography (PET) involve the interpretation of a subtracted PET image, usually the difference between two images under baseline and stimulation conditions. The purpose of these studies is to see which areas of the brain are activated
Results 1 - 10 of 12,102