Results 1  10
of
349
Ideal spatial adaptation by wavelet shrinkage
 Biometrika
, 1994
"... With ideal spatial adaptation, an oracle furnishes information about how best to adapt a spatially variable estimator, whether piecewise constant, piecewise polynomial, variable knot spline, or variable bandwidth kernel, to the unknown function. Estimation with the aid of an oracle o ers dramatic ad ..."
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Cited by 1269 (5 self)
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spline ts and piecewisepolynomial ts, when equipped with an oracle to select the knots, are not dramatically more powerful than selective wavelet reconstruction with an oracle. We develop a practical spatially adaptive method, RiskShrink, which works by shrinkage of empirical wavelet coe cients. Risk
Minimax Estimation via Wavelet Shrinkage
, 1992
"... We attempt to recover an unknown function from noisy, sampled data. Using orthonormal bases of compactly supported wavelets we develop a nonlinear method which works in the wavelet domain by simple nonlinear shrinkage of the empirical wavelet coe cients. The shrinkage can be tuned to be nearly minim ..."
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Cited by 321 (29 self)
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We attempt to recover an unknown function from noisy, sampled data. Using orthonormal bases of compactly supported wavelets we develop a nonlinear method which works in the wavelet domain by simple nonlinear shrinkage of the empirical wavelet coe cients. The shrinkage can be tuned to be nearly
b Coef®cient of volume expansion
"... convection flow of a micropolar fluid over a stretching sheet ..."
Errorcorrection Mechanism Tests for Cointegration in a Singleequation Framework
 Journal of Times Series Analysis
, 1998
"... Abstract. A new test is proposed for cointegration in a single equation framework where the regressors are weakly exogenous for the parameters of interest. The test is denoted as an error correction mechanism (ECM) test and is based upon the ordinary least squares coef®cient of the lagged dependent ..."
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Cited by 175 (2 self)
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Abstract. A new test is proposed for cointegration in a single equation framework where the regressors are weakly exogenous for the parameters of interest. The test is denoted as an error correction mechanism (ECM) test and is based upon the ordinary least squares coef®cient of the lagged dependent
Multicomponent apparent diffusion coef®cients in human brain²
"... ABSTRACT: The signal decay with increasing bfactor at fixed echo time from brain tissue in vivo has been measured using a line scan StejskalTanner spin echo diffusion approach in eight healthy adult volunteers. The use of a 175 ms echo time and maximum gradient strengths of 10 mT/m allowed 64 bf ..."
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ABSTRACT: The signal decay with increasing bfactor at fixed echo time from brain tissue in vivo has been measured using a line scan StejskalTanner spin echo diffusion approach in eight healthy adult volunteers. The use of a 175 ms echo time and maximum gradient strengths of 10 mT/m allowed 64 bfactors to be sampled, ranging from 5 to 6000 s/ mm 2 , a maximum some three times larger than that typically used for diffusion imaging. The signal decay with bfactor over this extended range showed a decidedly nonexponential behavior wellsuited to biexponential modeling. Statistical analyses of the fitted biexponential parameters from over 125 brain voxels (15 Â 15 Â 1 mm 3 volume) per volunteer yielded a mean volume fraction of 0.74 which decayed with a typical apparent diffusion coefficient around 1.4 mm 2 /ms. The remaining fraction had an apparent diffusion coefficient of approximately 0.25 mm 2 /ms. Simple models which might explain the nonexponential behavior, such as intraand extracellular water compartmentation with slow exchange, appear inadequate for a complete description. For typical diffusion imaging with bfactors below 2000 s/mm 2 , the standard model of monoexponential signal decay with bfactor, apparent diffusion coefficient values around 0.7 mm 2 /ms, and a sensitivity to diffusion gradient direction may appear appropriate. Over a more extended but readily accessible bfactor range, however, the complexity of brain signal decay with bfactor increases, offering a greater parametrization of the water diffusion process for tissue characterization.
Smoothing Spline Models for the Analysis of Nested and Crossed Samples of Curves
 Journal of the American Statistical Association
, 1998
"... We introduce a class of models for an additive decomposition of groups of curves strati ed by crossed and nested factors, generalizing smoothing splines to such samples by associating them with a corresponding mixed e ects model. The models are also useful for imputation of missing data and explorat ..."
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Cited by 127 (1 self)
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cubic splines. The model parameters are estimated using a highly e cient implementation of the EM algorithm for restricted maximum likelihood (REML) estimation based on a preliminary eigenvector decomposition. Variability of computed estimates can be assessed with asymptotic techniques or with a novel
stable computation of multipole translation and rotation coef cients for the 3D Helmholtz equation
, 2001
"... Abstract. We develop exact expressions for the coef cients of series representations of translations and rotations of local and multipole fundamental solutions of the Helmholtz equation in spherical coordinates. These expressions are based on the derivation of recurrence relations, some of which, to ..."
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Cited by 19 (5 self)
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Abstract. We develop exact expressions for the coef cients of series representations of translations and rotations of local and multipole fundamental solutions of the Helmholtz equation in spherical coordinates. These expressions are based on the derivation of recurrence relations, some of which
Surface Fitting with Hierarchical Splines
 ACM Transactions on Graphics
, 1995
"... We consider the fitting of tensor product parametric spline surfaces to gridded data. The continuity of the surface is provided by the basis chosen. When tensor product splines are used with gridded data, the surface fitting problem decomposes into a sequence of curve fitting processes, making the c ..."
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Cited by 57 (1 self)
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We consider the fitting of tensor product parametric spline surfaces to gridded data. The continuity of the surface is provided by the basis chosen. When tensor product splines are used with gridded data, the surface fitting problem decomposes into a sequence of curve fitting processes, making
Improved Satellite Drag Coef cient Calculations from Orbital Measurements of Energy Accommodation
"... Signi cant discoveries about gas–surface interactions that havebeen made in 90 years of laboratory experiments and 30 years of orbital measurements are reviewed. This information is used to improve the calculation of drag coef cients for satellites in low Earth orbit for several different satellit ..."
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Signi cant discoveries about gas–surface interactions that havebeen made in 90 years of laboratory experiments and 30 years of orbital measurements are reviewed. This information is used to improve the calculation of drag coef cients for satellites in low Earth orbit for several different
Results 1  10
of
349