Results 181 to 190 of about 15,466 (317)
Magnetic Resonance in Medicine, EarlyView.ABSTRACT Purpose To improve the accuracy of diffusion‐weighted powder average signals for diffusion encoding with arbitrary b‐tensors. Methods We identify an intrinsic dihedral (D2$$ {D}_2 $$) symmetry of diffusion signals for arbitrary diffusion encoding, which defines their natural signal space (a quotient of 3D rotations).
Sune Nørhøj Jespersen +1 more
wiley +1 more source
Image Encoding With Blipped Gradients in an Echo Train
Magnetic Resonance in Medicine, EarlyView.ABSTRACT Purpose An MRI scanner was designed and built to encode k$$ k $$‐space points in the spin echoes occurring between 180∘$$ 18{0}^{\circ } $$ pulses in an echo train by using blipped B0$$ {B}_0 $$ gradient pulses applied just prior to those spin echoes.
Logi Vidarsson, Gordon E. Sarty
wiley +1 more source
The relationship between equatorial wave interaction and heavy rainfall in Southeast Asia
Quarterly Journal of the Royal Meteorological Society, EarlyView.This study examines the statistical relationship between co‐occurring equatorial waves and heavy rainfall in Southeast Asia. Heavy rainfall is more closely related to combined wave activity than to individual waves in many regions of Southeast Asia. The figure shows GPM–IMERG rainfall (shading) and ERA5 850‐hPa winds (vectors) composited on days when ...
Samantha Ferrett +7 more
wiley +1 more source
An Orthogonal Polynomial Approach to Estimate the Term Structure of Interest Rates [PDF]
In this paper, we introduce a new algorithm to estimate the term structure of interest rates. It is obtained from a constrained optimization, where the objective is to minimize the integral of squared first derivatives of the instantaneous forward ...
Hans-Jürg Büttler
core
Epistemic and aleatoric uncertainty quantification in weather and climate models
Quarterly Journal of the Royal Meteorological Society, EarlyView.Aleatoric and epistemic uncertainties over time on weather and climate time‐scales, estimated through ensembles that sample aleatoric and epistemic uncertainty using Bayesian neural networks for parameterisations in the Lorenz 1996 model. The spread shows the 16th and 84th percentiles.
Laura A. Mansfield +1 more
wiley +1 more source
Elliptic Biorthogonal Polynomials Connected with Hermite's Continued Fraction
Symmetry, Integrability and Geometry: Methods and Applications, 2007 We study a family of the Laurent biorthogonal polynomials arising from the Hermite continued fraction for a ratio of two complete elliptic integrals. Recurrence coefficients, explicit expression and the weight function for these polynomials are obtained.
Luc Vinet, Alexei Zhedanov
doaj
Discrete Transforms and Orthogonal Polynomials of (Anti)symmetric Multivariate Sine Functions. [PDF]
Entropy (Basel), 2018 Brus A, Hrivnák J, Motlochová L.
europepmc +1 more source
New views of some invariants associated with the Cartesian 2D velocity gradient tensor
Quarterly Journal of the Royal Meteorological Society, EarlyView.Vorticity and divergence of horizontal flow are fundamental quantities in meteorology; both are linear functions of the four elements of the 2D velocity gradient tensor and both are formally unchanged under coordinate rotation. We explore four quadratic functions of the elements that are geometrically invariant in this sense, finding some novel ...
I. Roulstone, S. A. Clough, A. A. White
wiley +1 more source
Boundary characteristic orthogonal polynomials method in the vibration analysis of multi-span plates acting upon a moving mass. [PDF]
Heliyon, 2019 Kashani Rad H +2 more
europepmc +1 more source
Quarterly Journal of the Royal Meteorological Society, EarlyView.An energy‐conserving discrete framework for the vertical discretisation of stratified ocean models is developed using internal gravity‐wave theory. A β$$ \beta $$‐indexed family of schemes is analysed through perturbation theory, revealing optimal parameter choices and grid designs that reduce truncation errors significantly.
Gabriel Derrida +3 more
wiley +1 more source