1,838 research outputs found
Structure and Dynamics of a Phase-Separating Active Colloidal Fluid
We examine a minimal model for an active colloidal fluid in the form of
self-propelled Brownian hard spheres that interact purely through excluded
volume. Despite the absence of an aligning interaction, this system shows the
signature behaviors of an active fluid, including anomalous number fluctuations
and phase separation behavior. Using simulations and analytic modeling, we
quantify the phase diagram and separation kinetics. The dense phase is a unique
material that we call an active hexatic, which exhibits the structural
signatures of a crystalline solid near the crystal-hexatic transition point,
but the rheological and transport properties associated with a viscoelastic
fluid.Comment: 5 pages, 5 figure
Spectral Clustering with Jensen-type kernels and their multi-point extensions
Motivated by multi-distribution divergences, which originate in information
theory, we propose a notion of `multi-point' kernels, and study their
applications. We study a class of kernels based on Jensen type divergences and
show that these can be extended to measure similarity among multiple points. We
study tensor flattening methods and develop a multi-point (kernel) spectral
clustering (MSC) method. We further emphasize on a special case of the proposed
kernels, which is a multi-point extension of the linear (dot-product) kernel
and show the existence of cubic time tensor flattening algorithm in this case.
Finally, we illustrate the usefulness of our contributions using standard data
sets and image segmentation tasks.Comment: To appear in IEEE Computer Society Conference on Computer Vision and
Pattern Recognitio
Influence of Ni doping on the electronic structure of Ni_2MnGa
The modifications in the electronic structure of Ni_{2+x}Mn_{1-x}Ga by Ni
doping have been studied using full potential linearized augmented plane wave
method and ultra-violet photoemission spectroscopy. Ni 3d related electron
states appear due to formation of Ni clusters. We show the possibility of
changing the minority-spin DOS with Ni doping, while the majority-spin DOS
remains almost unchanged. The total magnetic moment decreases with excess Ni.
The total energy calculations corroborate the experimentally reported changes
in the Curie temperature and the martensitic transition temperature with x.Comment: 4 pages, 4 figures, accepted in Phys. Rev.
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