Search results for "BESS"
showing 10 items of 144 documents
Zvaigžņotā Debess: 2017/18, Ziema (238)
2017
Contents: “ZVAIGŽŅOTĀ DEBESS” FORTY YEARS AGO: I.Vilka. Starry Sky and Birds’ Journeys (abridged) ; N.Cimahoviča. Spirals of Saturn’s Rings (abridged) ; I.Šmelds. V Readings of Friedrich Zander ; DEVELOPMENTS in SCIENCE: K.Schwartz. Most Distant Galaxy Clusters and 3D Structure of the Universe ; DISCOVERIES: M.Gills. The Day when Multi-Messenger Astronomy Was Announced ; I.Pundure. ESO Telescopes and Hubble Observe the Source of Gravitational Waves for the First Time ; I.Eglītis. Asteroid “Balklavs” ; SPACE RESEARCH and EXPLORATION: R.Misa. Mission of Cassini – Discoveries to the Very End ; J.Jaunbergs. The Icy World Tethys ; OBSERVATORIES and INSTRUMENTS: M.Gills. The Giant Radio Telescope…
On first exit times and their means for Brownian bridges
2017
For a Brownian bridge from $0$ to $y$ we prove that the mean of the first exit time from interval $(-h,h), \,\, h>0,$ behaves as $O(h^2)$ when $h \downarrow 0.$ Similar behavior is seen to hold also for the 3-dimensional Bessel bridge. For Brownian bridge and 3-dimensional Bessel bridge this mean of the first exit time has a puzzling representation in terms of the Kolmogorov distribution. The result regarding the Brownian bridge is applied to prove in detail an estimate needed by Walsh to determine the convergence of the binomial tree scheme for European options.
On 1-Laplacian Elliptic Equations Modeling Magnetic Resonance Image Rician Denoising
2015
Modeling magnitude Magnetic Resonance Images (MRI) rician denoising in a Bayesian or generalized Tikhonov framework using Total Variation (TV) leads naturally to the consideration of nonlinear elliptic equations. These involve the so called $1$-Laplacian operator and special care is needed to properly formulate the problem. The rician statistics of the data are introduced through a singular equation with a reaction term defined in terms of modified first order Bessel functions. An existence theory is provided here together with other qualitative properties of the solutions. Remarkably, each positive global minimum of the associated functional is one of such solutions. Moreover, we directly …
Stochastic acceleration in generalized squared Bessel processes
2015
We analyze the time behavior of generalized squared Bessel processes, which are useful for modeling the relevant scales of stochastic acceleration problems. These nonstationary stochastic processes obey a Langevin equation with a non-Gaussian multiplicative noise. We obtain the long-time asymptotic behavior of the probability density function for non-Gaussian white and colored noise sources. We find that the functional form of the probability density functions is independent of the statistics of the noise source considered. Theoretical results are in good agreement with those obtained by numerical simulations of the Langevin equation with pulse noise sources.
Plan d’action suffragiste en faveur de la cause féminine: femmes rédactrices, catalyseurs des réformes sociales et politiques dans l’Angleterre victo…
2019
National audience; La suppression du droit de timbre en 1855 et des taxes sur le papier en 1861, en Angleterre, favorise la création de plusieurs organes de presse dont le magazine féministe The Englishwoman’s Journal (1858-1864). Sa stratégie éditoriale consiste à promouvoir les analyses critiques des journalistes de sexe féminin contre les politiques conservatrices anglaises concernant la condition féminine. Les co-fondatrices du groupe de Langham Place, Barbara Leigh Smith (1827-1891) et Bessie Rayner Parkes (1829-1925), donnent la parole à la communauté féminine qui n’a de véritable possibilité d’expression et de communication que l’écriture. Se dégageant de toute restriction d’expressi…
Single-shot ultrafast laser processing of high-aspect-ratio nanochannels using elliptical Bessel beams
2017
Ultrafast lasers have revolutionized material processing, opening a wealth of new applications in many areas of science. A recent technology that allows the cleaving of transparent materials via non-ablative processes is based on focusing and translating a high-intensity laser beam within a material to induce a well-defined internal stress plane. This then enables material separation without debris generation. Here, we use a non-diffracting beam engineered to have a transverse elliptical spatial profile to generate high aspect ratio elliptical channels in glass of dimension 350 nm x 710 nm, and subsequent cleaved surface uniformity at the sub-micron level.
Zvaigžņotā Debess: 2019, Vasara (244)
2019
Stationary heat flux profile in turbulent helium II in a semi-infinite cylindrical channel
2012
In this paper we determine a set of solutions for a system of partial dif- ferential equations describing stationary heat flux in a semi-infinite cylindrical channel filled with turbulent superfluid helium. This study uses a continuous model for liquid helium II, derived from Extended Thermodynamics, in which the heat flux q is a fundamental variable. The influence of the vortex line den- sity on the radial distribution of the heat flux is especially discussed.
La historia imaginada por el cine europeo de finales del siglo XX. Chéreau, Besson, Olmi
2017
Análisis de tres películas de historia europeas de la última década del siglo XX. La reina Margot, Patrice Chéreau, 1994; Juana de Arco de Luc Besson, 1999; El oficio de las armas, Ermanno Olmi, 2001. La tesis muestra las diferentes formas en que este cine neobarroco se conjuga con la historia, atendiendo al análisis del cine en su relación con la historia, las fuentes escritas e iconográficas, el teatro, las artes plásticas, el cómic, la cultura popular, así como con el propio cine. También hace especial mención a las representaciones sociales como forma de conocimiento propia del cine.
The exact distribution of a weighted Convolution of two Gamma distributions
2006
Si considera una rappresentazione della funzione di densit`a di probabilit`a di una Convoluzione ponderata di distribuzioni Gamma, in cui una funzione ipergeometrica confluente descrive come le differenze tra i parametri di scala delle componenti determinino allontanamenti da una densit`a Gamma. Si considera il caso specifico di una convoluzione di due variabili gamma per mostrare, come al vantaggio interpretativo si aggiunga la possibilit`a di derivare in forma esplicita e computazionalmente semplice, espressioni della funzione di ripartizione e dei momenti. Si mostra la relazione tra tale distribuzione ed il sistema delle distribuzioni di Bessel, e si generalizza inoltre al caso di convol…