Search results for "Regular"
showing 10 items of 855 documents
Locally Convex *-Algebras and the Thermodynamical Limit of Quantum Models
2000
We show that the thermodynamical limit of several physical models is naturally obtained within the framework of topological quasi *-algebras. In particular, the relevance of the algebra L + (D) is shown explicitly by concrete examples.
A comparative study of partitioning methods for crowd simulations
2010
The simulation of large crowds of autonomous agents with realistic behavior is still a challenge for several computer research communities. In order to handle large crowds, some scalable architectures have been proposed. Nevertheless, the effective use of distributed systems requires the use of partitioning methods that can properly distribute the workload generated by agents among the existing distributed resources. In this paper, we analyze the use of irregular shape regions (convex hulls) for solving the partitioning problem. We have compared a partitioning method based on convex hulls with two techniques that use rectangular regions. The performance evaluation results show that the conv…
Convexly generic curves in R 3
1988
We study curves immersed in R 3, with special interest in the description of their convex hull frontier structure from a global viewpoint. Genericity conditions are set for these curves by looking at the singularities of height functions on them. We define panel structures for convexly generic curves and work out numerical relations involving the number of tritangent support planes. As a consequence, a generic version of the 4-vertex theorem for convex curves in R 3 is obtained.
Delta- and Daugavet points in Banach spaces
2020
AbstractA Δ-pointxof a Banach space is a norm-one element that is arbitrarily close to convex combinations of elements in the unit ball that are almost at distance 2 fromx. If, in addition, every point in the unit ball is arbitrarily close to such convex combinations,xis a Daugavet point. A Banach spaceXhas the Daugavet property if and only if every norm-one element is a Daugavet point. We show that Δ- and Daugavet points are the same inL1-spaces, inL1-preduals, as well as in a big class of Müntz spaces. We also provide an example of a Banach space where all points on the unit sphere are Δ-points, but none of them are Daugavet points. We also study the property that the unit ball is the clo…
Infrared renormalization of two-loop integrals and the chiral expansion of the nucleon mass
2007
We describe details of the renormalization of two-loop integrals relevant to the calculation of the nucleon mass in the framework of manifestly Lorentz-invariant chiral perturbation theory using infrared renormalization. It is shown that the renormalization can be performed while preserving all relevant symmetries, in particular chiral symmetry, and that renormalized diagrams respect the standard power counting rules. As an application we calculate the chiral expansion of the nucleon mass to order O(q^6).
Communicative memory of irregular migration: The re-circulation of news images on YouTube
2016
This article analyses user-generated YouTube cut and mix videos of irregular migration as producing communicative memory of those who have suffered at Europe’s external borders. Visual and textual analyses examine a neglected perspective on the study of media representations of migration by examining a particular practice through which people engage with news images and participate in (re)construction of collective memory in relation to irregular migration. The analysis shows that while hegemonic Eurocentric imagery prevails also in the vernacular amateur productions, re-mixing different cultural productions nevertheless complicates the representation of irregular migration and affords alte…
Estudio climático del exponente “n” de las curvas IDF: aplicación para la Península Ibérica
2009
El análisis de las precipitaciones máximas suele llevarse a cabo mediante curvas IDF (Intensidad-Duración-Frecuencia), que a su vez pueden expresarse como curvas IMM (Intensidades Medias Máximas). En este trabajo, hemos desarrollado un índice “n”, definido a partir del exponente que se obtiene de ajustar las curvas climáticas IDF a las curvas IMM. Dicho índice proporciona información sobre el modo en que se alcanzan las precipitaciones máximas en una determinada zona clim´atica, atendiendo a la distribuci´on temporal relativa de las intensidades m´aximas. A partir del an´alisis clim´atico del ´ındice “n”, en la Pen´ınsula Ib´erica se pueden distinguir grandes zonas caracterizadas por m´axim…
Limits of Sobolev homeomorphisms
2017
Let X; Y subset of R-2 be topologically equivalent bounded Lipschitz domains. We prove that weak and strong limits of homeomorphisms h: X (onto)-> Y in the Sobolev space W-1,W-p (X, R-2), p >= 2; are the same. As an application, we establish the existence of 2D-traction free minimal deformations for fairly general energy integrals. Peer reviewed
Sequential Learning with LS-SVM for Large-Scale Data Sets
2006
We present a subspace-based variant of LS-SVMs (i.e. regularization networks) that sequentially processes the data and is hence especially suited for online learning tasks. The algorithm works by selecting from the data set a small subset of basis functions that is subsequently used to approximate the full kernel on arbitrary points. This subset is identified online from the data stream. We improve upon existing approaches (esp. the kernel recursive least squares algorithm) by proposing a new, supervised criterion for the selection of the relevant basis functions that takes into account the approximation error incurred from approximating the kernel as well as the reduction of the cost in th…
Quasi-Newton approach to nonnegative image restorations
2000
Abstract Image restoration, or deblurring, is the process of attempting to correct for degradation in a recorded image. Typically the blurring system is assumed to be linear and spatially invariant, and fast Fourier transform (FFT) based schemes result in efficient computational image restoration methods. However, real images have properties that cannot always be handled by linear methods. In particular, an image consists of positive light intensities, and thus a nonnegativity constraint should be enforced. This constraint and other ways of incorporating a priori information have been suggested in various applications, and can lead to substantial improvements in the reconstructions. Neverth…