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نتایج جستجو برای Curvilinear anisotropy

تعداد نتایج: 22226  
Journal: :Neurocomputing 2004
John Aldo Lee, Amaury Lendasse, Michel Verleysen,

Dimension reduction techniques are widely used for the analysis and visualization of complex sets of data. This paper compares two recently published methods for nonlinear projection: Isomap and Curvilinear Distance Analysis (CDA). Contrarily to the traditional linear PCA, these methods work like multidimensional scaling, by reproducing in the projection space the pairwise distances measured in...

2007
Pierre Demartines,

R esum e : L'ACC est un r eseau de neurones auto-organis e qui donne une carte de la sous-vari et e d'un nuage de donn ees en grandes dimensions non lin eairement d ependantes. Le principe est de construire une relation entre un espace d'entr ee (les don-n ees) et un espace de sortie (la carte) au moyen d'un ensemble de neurones ayant chacun deux vecteurs-poids : un pour l'entr ee et l'autre po...

2013
Robin A. Damion, Aleksandra Radjenovic, Eileen Ingham, Zhongmin Jin, Michael E. Ries,

We develop a curvilinear invariant set of the diffusion tensor which may be applied to Diffusion Tensor Imaging measurements on tissues and porous media. This new set is an alternative to the more common invariants such as fractional anisotropy and the diffusion mode. The alternative invariant set possesses a different structure to the other known invariant sets; the second and third members of...

1995
Xiaoyang Mao, Lichan Hong, Arie E. Kaufman,

This paper presents a splatting algorithm for volume rendering of curvilinear grids. A stochastic sampling technique called Poisson sphere/ellipsoid sampling is employed to adaptively resample a curvilinear grid with a set of randomly distributed points whose energy support extents are well approximated by spheres and ellipsoids. Filter kernels corresponding to these spheres and ellipsoids are ...

2010
Shuodao Wang, Jianliang Xiao, Jizhou Song, Heung Cho Ko, Keh-Chih Hwang, Yonggang Huang, John A. Rogers,

Advanced methods are now available for conformally wrapping planar, silicon-based electronics circuits onto complex, curvilinear surfaces. Here, buckling physics of circuits configured into mesh geometries consisting of silicon islands interconnected by narrow ribbons leads to out of plane displacements across different parts of the curvilinear surface, in a way that accommodates strains associ...

Journal: :Journal of Approximation Theory 2001
Emmanuel J. Candès, David L. Donoho,

Let C(t) : I 7→ R be a simple closed unit-speed C curve in R with normal ~n(t). The curve C generates a distribution Γ which acts on vector fields ~v(x1, x2) : R 2 7→ R by line integration according to Γ(~v) = ∫ ~v(C(t)) · ~n(t)dt. We consider the problem of efficiently approximating such functionals. Suppose we have a vector basis or frame Φ = (~ φμ); then an m-term approximation to Γ can be f...

2000
A A Abrikosov,

The 'tHooft's 5N-parametric multiinstanton solution is generalized to curvilinear coordinates. Expressions can be simplified by the gauge transformation that makes η-symbols constant in the vierbein formalism. This generates the compensating addition to the gauge potential of pseudoparticles. Typical examples (4-spherical, 2 + 2-and 3 + 1-cylindrical coordinates) are studied and explicit formul...

1999
A. A. Abrikosov,

The multi-instanton solutions by ’tHooft and Jackiw, Nohl & Rebbi are generalized to curvilinear coordinates. Expressions can be notably simplified by the appropriate gauge transformation. This generates the compensating addition to the gauge potential of pseudoparticles. Singularities of the compensating connection are irrelevant for physics but affect gauge dependent quantities. The third con...

2007
David M. Reed, Lawson Wade, Peter G. Carswell, Wayne E. Carlson,

Computational fluid dynamics simulations result in large multivariate data sets with information such as pressure, temperature and velocity available at grid points for a sequence of steps. Velocity data is typically visualized by displaying a particle animation or streamlines. We present an efficient method for calculating particle paths based on velocity data from curvilinear grids. In order ...

Journal: :J. Comput. Physics 2012
Jean-François Remacle, Thomas Toulorge, Jonathan Lambrechts,

This paper describes a technique that enables to generate high order / curvilinear meshes in a robust fashion. Accurate estimates of jacobian bounds are used for deriving an unconstrained optimization procedure. Both 2D and 3D valid high order meshes are presented that demonstrate the efficiency of the new technique.