1000 resultados para D-ASTERISK VERTEX


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We calculate the form factors and the coupling constant in the D*D rho vertex in the framework of QCD sum rules. We evaluate the three-point correlation functions of the vertex considering D, rho and D* mesons off-shell. The form factors obtained are very different but give the same coupling constant: g(D*D rho) = 4.3 +/- 0.9 GeV(-1). (C) 2011 Elsevier B.V. All rights reserved.

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We evaluate the mass of the B(s0) scalar meson and the coupling constant in the B(s0)BK vertex in the framework of QCD sum rules. We consider the B(s0) as a tetraquark state to evaluate its mass. We get m(Bs0) = (5.85 +/- 0.13) GeV, which is in agreement, considering the uncertainties, with predictions supposing it as a b (s) over bar state or a B (K) over bar bound state with J(P) = 0(+). To evaluate the g(Bs0BK) coupling, we use the three-point correlation functions of the vertex, considering B(s0) as a normal b (s) over bar state. The obtained coupling constant is: g(Bs0BK) = (16.3 +/- 3.2) GeV. This number is in agreement with light-cone QCD sum rules calculation. We have also compared the decay width of the B(s0) -> BK process considering the B(s0) to be a b (s) over bar state and a BK molecular state. The width obtained for the BK molecular state is twice as big as the width obtained for the b (s) over bar state. Therefore, we conclude that with the knowledge of the mass and the decay width of the B(s0) meson, one can discriminate between the different theoretical proposals for its structure.

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With this final master thesis we are going to contribute to the Asterisk open source project. Asterisk is an open source project that started with the main objective of develop an IP telephony platform, completely based on Software (so not hardware dependent) and under an open license like GPL. This project was started on 1999 by the software engineer Mark Spencer at Digium. The main motivation of that open source project was that the telecommunications sector is lack of open solutions, and most of the available solutions are based on proprietary standards, which are close and not compatible between them. Behind the Asterisk project there is a company, Digum, which is the project leading since the project was originated in its laboratories. This company has some of its employees fully dedicated to contribute to the Asterisk project, and also provide the whole infrastructure required by the open source project. But the business of Digium isn't based on licensing of products due to the open source nature of Asterisk, but it's based on offering services around Asteriskand designing and selling some hardware components to be used with Asterisk. The Asterisk project has grown up a lot since its birth, offering in its latest versions advanced functionalities for managing calls and compatibility with some hardware that previously was exclusive of proprietary solutions. Due to that, Asterisk is becoming a serious alternative to all these proprietaries solutions because it has reached a level of maturity that makes it very stable. In addition, as it is open source, it can be fully customized to a givenrequirement, which could be impossible with the proprietaries solutions. Due to the bigness that is reaching the project, every day there are more companies which develop value added software for telephony platforms, that are seriously evaluating the option of make their software fully compatible withAsterisk platforms. All these factors make Asterisk being a consolidated project but in constant evolution, trying to offer all those functionalities offered by proprietaries solutions. This final master thesis will be divided mainly in two blocks totally complementaries. In the first block we will analyze Asterisk as an open source project and Asterisk as a telephony platform (PBX). As a result of this analysis we will generate a document, written in English because it is Asterisk project's official language, which could be used by future contributors as an starting point on joining Asterisk. On the second block we will proceed with a development contribution to the Asterisk project. We will have several options in the form that we do the contribution, such as solving bugs, developing new functionalities or start an Asterisk satellite project. The type of contribution will depend on the needs of the project on that moment.

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L'expérience LHCb sera installée sur le futur accélérateur LHC du CERN. LHCb est un spectromètre à un bras consacré aux mesures de précision de la violation CP et à l'étude des désintégrations rares des particules qui contiennent un quark b. Actuellement LHCb se trouve dans la phase finale de recherche et développement et de conception. La construction a déjà commencé pour l'aimant et les calorimètres. Dans le Modèle Standard, la violation CP est causée par une phase complexe dans la matrice 3x3 CKM (Cabibbo-Kobayashi-Maskawa) de mélange des quarks. L'expérience LHCb compte utiliser les mesons B pour tester l'unitarité de cette matrice, en mesurant de diverses manières indépendantes tous les angles et côtés du "triangle d'unitarité". Cela permettra de surdéterminer le modèle et, peut-être, de mettre en évidence des incohérences qui seraient le signal de l'existence d'une physique au-delà du Modèle Standard. La reconstruction du vertex de désintégration des particules est une condition fondamentale pour l'expérience LHCb. La présence d'un vertex secondaire déplacé est une signature de la désintégration de particules avec un quark b. Cette signature est utilisée dans le trigger topologique du LHCb. Le Vertex Locator (VeLo) doit fournir des mesures précises de coordonnées de passage des traces près de la région d'interaction. Ces points sont ensuite utilisés pour reconstruire les trajectoires des particules et l'identification des vertices secondaires et la mesure des temps de vie des hadrons avec quark b. L'électronique du VeLo est une partie essentielle du système d'acquisition de données et doit se conformer aux spécifications de l'électronique de LHCb. La conception des circuits doit maximiser le rapport signal/bruit pour obtenir la meilleure performance de reconstruction des traces dans le détecteur. L'électronique, conçue en parallèle avec le développement du détecteur de silicium, a parcouru plusieurs phases de "prototyping" décrites dans cette thèse.<br/><br/>The LHCb experiment is being built at the future LHC accelerator at CERN. It is a forward single-arm spectrometer dedicated to precision measurements of CP violation and rare decays in the b quark sector. Presently it is finishing its R&D and final design stage. The construction already started for the magnet and calorimeters. In the Standard Model, CP violation arises via the complex phase of the 3 x 3 CKM (Cabibbo-Kobayashi-Maskawa) quark mixing matrix. The LHCb experiment will test the unitarity of this matrix by measuring in several theoretically unrelated ways all angles and sides of the so-called "unitary triangle". This will allow to over-constrain the model and - hopefully - to exhibit inconsistencies which will be a signal of physics beyond the Standard Model. The Vertex reconstruction is a fundamental requirement for the LHCb experiment. Displaced secondary vertices are a distinctive feature of b-hadron decays. This signature is used in the LHCb topology trigger. The Vertex Locator (VeLo) has to provide precise measurements of track coordinates close to the interaction region. These are used to reconstruct production and decay vertices of beauty-hadrons and to provide accurate measurements of their decay lifetimes. The Vertex Locator electronics is an essential part of the data acquisition system and must conform to the overall LHCb electronics specification. The design of the electronics must maximise the signal to noise ratio in order to achieve the best tracking reconstruction performance in the detector. The electronics is being designed in parallel with the silicon detector development and went trough several prototyping phases, which are described in this thesis.

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L'objectiu d'aquest projecte és la creació d'una prova de concepte de comunicacions unificades utilitzant productes de programari lliure existents. Aquesta prova de concepte servirà per poder fer demostracions del funcionament general del programari implicat amb el mínim de preparacions, instal·lacions i configuracions prèvies possibles. El projecte es dividirà en dos appliances o LiveCD, creats a traves de Suse Studio, anomenats Comunicacions Unificades i Comunicacions Unificades 2.Els productes de programari lliure que composen el Servidor de Comunicacions Unificades els podem classificar en productes principals, plugins o addons dels productes i productes secundaris.Com a productes principals tenim els següents servidors que cobreixen les necessitats principals del Servidor de Comunicacions Unificades:Asterisk v1.8.3 : Servidor de telefonia amb veu sobre IP (VoIP).FreePBX v2.9.0beta2 : GUI de control i administració d'Asterisk.Openfire v3.7.0 : Servidor de IM basat en el protocol XMPP.BigBlueButton v0.71a : Sistema de conferència web. Pendent finalitzar-ne l'implementació.I els seguents productes principals que cobreixen les necessitats del servidor de Comunicacions Unificades 2:Zimbra v7.0.1 : Servidor de correu electrònic i de calendari. Pendent resoldre conflicte inicialització LDAP.Funambol v9.0.0 : Sincronització Zimbra amb mòbils.Com a plugins o addons del productes tenim, classificats segons el producte:Asterisk addons: chan_jingle i chan_gtalkZimlets: Asterisk, Google Translator, Funambol i SocialsOpenfire pugins: Asterisk, Facebook i GmailCom a productes secundaris tenim els clients necessaris per poder utilitzar l'appliance:Firefox: Navegador web que servirà com a interfície d'usuari per les diferents eines d'administració i la demostració.Pigdin o Spark: Clients de missatgeria instantània, per l'appliance Comunicacions Unificades.A més d'instal·lar aquests productes, s'implementa una interfície web, mitjançant Drupal, en format HTML per enllaçar les diferents eines d'administració dels productes, per a cadascun dels dos appliances i es realitzara un Kiosk appliance per a familiaritzar-se amb l'entorn SuseStudio.

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A systematic determination of the gluon distribution is of fundamental interest in understanding the parton structure Of nuclei and the QCD dynamics. Currently, the behavior of this distribution at small x (high energy) is completely undefined. In this Letter we analyze the possibility of constraining the nuclear effects present in Xg(A) using the inclusive observables which would be measured in the future electron-nucleus collider at RHIC. We demonstrate that the Study of nuclear longitudinal and charm structure functions allows to estimate the magnitude of shadowing and antishadowing effects in the nuclear gluon distribution. (C) 2008 Elsevier B.V. All rights reserved.

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We calculate the form factors and the coupling constant in the rho D*D* vertex in the framework of QCD sum rules. We evaluate the three point correlation functions of the vertex considering both rho and D* mesons off-shell. The form factors obtained are very different but give the same coupling constant: g rho D*D* = 6.60 +/- 0.31. This number is 50% larger than what we would expect from SU(4) estimates. (c) 2007 Elsevier B.V. All rights reserved.

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Using the pure spinor formalism for the superstring, the vertex operator for the first massive states of the open superstring is constructed in a manifestly super-Poincare covariant manner. This vertex operator describes a massive spin-two multiplet in terms of ten-dimensional superfields.

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Using the pure spinor formalism for the superstring, the vertex operator for the first massive states of the open superstring is constructed in a manifestly super-Poincaré covariant manner. This vertex operator describes a massive spin-two multiplet in terms of ten-dimensional superfields. © SISSA/ISAS 2002.

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Hyperspectral remote sensing exploits the electromagnetic scattering patterns of the different materials at specific wavelengths [2, 3]. Hyperspectral sensors have been developed to sample the scattered portion of the electromagnetic spectrum extending from the visible region through the near-infrared and mid-infrared, in hundreds of narrow contiguous bands [4, 5]. The number and variety of potential civilian and military applications of hyperspectral remote sensing is enormous [6, 7]. Very often, the resolution cell corresponding to a single pixel in an image contains several substances (endmembers) [4]. In this situation, the scattered energy is a mixing of the endmember spectra. A challenging task underlying many hyperspectral imagery applications is then decomposing a mixed pixel into a collection of reflectance spectra, called endmember signatures, and the corresponding abundance fractions [8–10]. Depending on the mixing scales at each pixel, the observed mixture is either linear or nonlinear [11, 12]. Linear mixing model holds approximately when the mixing scale is macroscopic [13] and there is negligible interaction among distinct endmembers [3, 14]. If, however, the mixing scale is microscopic (or intimate mixtures) [15, 16] and the incident solar radiation is scattered by the scene through multiple bounces involving several endmembers [17], the linear model is no longer accurate. Linear spectral unmixing has been intensively researched in the last years [9, 10, 12, 18–21]. It considers that a mixed pixel is a linear combination of endmember signatures weighted by the correspondent abundance fractions. Under this model, and assuming that the number of substances and their reflectance spectra are known, hyperspectral unmixing is a linear problem for which many solutions have been proposed (e.g., maximum likelihood estimation [8], spectral signature matching [22], spectral angle mapper [23], subspace projection methods [24,25], and constrained least squares [26]). In most cases, the number of substances and their reflectances are not known and, then, hyperspectral unmixing falls into the class of blind source separation problems [27]. Independent component analysis (ICA) has recently been proposed as a tool to blindly unmix hyperspectral data [28–31]. ICA is based on the assumption of mutually independent sources (abundance fractions), which is not the case of hyperspectral data, since the sum of abundance fractions is constant, implying statistical dependence among them. This dependence compromises ICA applicability to hyperspectral images as shown in Refs. [21, 32]. In fact, ICA finds the endmember signatures by multiplying the spectral vectors with an unmixing matrix, which minimizes the mutual information among sources. If sources are independent, ICA provides the correct unmixing, since the minimum of the mutual information is obtained only when sources are independent. This is no longer true for dependent abundance fractions. Nevertheless, some endmembers may be approximately unmixed. These aspects are addressed in Ref. [33]. Under the linear mixing model, the observations from a scene are in a simplex whose vertices correspond to the endmembers. Several approaches [34–36] have exploited this geometric feature of hyperspectral mixtures [35]. Minimum volume transform (MVT) algorithm [36] determines the simplex of minimum volume containing the data. The method presented in Ref. [37] is also of MVT type but, by introducing the notion of bundles, it takes into account the endmember variability usually present in hyperspectral mixtures. The MVT type approaches are complex from the computational point of view. Usually, these algorithms find in the first place the convex hull defined by the observed data and then fit a minimum volume simplex to it. For example, the gift wrapping algorithm [38] computes the convex hull of n data points in a d-dimensional space with a computational complexity of O(nbd=2cþ1), where bxc is the highest integer lower or equal than x and n is the number of samples. The complexity of the method presented in Ref. [37] is even higher, since the temperature of the simulated annealing algorithm used shall follow a log( ) law [39] to assure convergence (in probability) to the desired solution. Aiming at a lower computational complexity, some algorithms such as the pixel purity index (PPI) [35] and the N-FINDR [40] still find the minimum volume simplex containing the data cloud, but they assume the presence of at least one pure pixel of each endmember in the data. This is a strong requisite that may not hold in some data sets. In any case, these algorithms find the set of most pure pixels in the data. PPI algorithm uses the minimum noise fraction (MNF) [41] as a preprocessing step to reduce dimensionality and to improve the signal-to-noise ratio (SNR). The algorithm then projects every spectral vector onto skewers (large number of random vectors) [35, 42,43]. The points corresponding to extremes, for each skewer direction, are stored. A cumulative account records the number of times each pixel (i.e., a given spectral vector) is found to be an extreme. The pixels with the highest scores are the purest ones. N-FINDR algorithm [40] is based on the fact that in p spectral dimensions, the p-volume defined by a simplex formed by the purest pixels is larger than any other volume defined by any other combination of pixels. This algorithm finds the set of pixels defining the largest volume by inflating a simplex inside the data. ORA SIS [44, 45] is a hyperspectral framework developed by the U.S. Naval Research Laboratory consisting of several algorithms organized in six modules: exemplar selector, adaptative learner, demixer, knowledge base or spectral library, and spatial postrocessor. The first step consists in flat-fielding the spectra. Next, the exemplar selection module is used to select spectral vectors that best represent the smaller convex cone containing the data. The other pixels are rejected when the spectral angle distance (SAD) is less than a given thresh old. The procedure finds the basis for a subspace of a lower dimension using a modified Gram–Schmidt orthogonalizati on. The selected vectors are then projected onto this subspace and a simplex is found by an MV T pro cess. ORA SIS is oriented to real-time target detection from uncrewed air vehicles using hyperspectral data [46]. In this chapter we develop a new algorithm to unmix linear mixtures of endmember spectra. First, the algorithm determines the number of endmembers and the signal subspace using a newly developed concept [47, 48]. Second, the algorithm extracts the most pure pixels present in the data. Unlike other methods, this algorithm is completely automatic and unsupervised. To estimate the number of endmembers and the signal subspace in hyperspectral linear mixtures, the proposed scheme begins by estimating sign al and noise correlation matrices. The latter is based on multiple regression theory. The signal subspace is then identified by selectin g the set of signal eigenvalue s that best represents the data, in the least-square sense [48,49 ], we note, however, that VCA works with projected and with unprojected data. The extraction of the end members exploits two facts: (1) the endmembers are the vertices of a simplex and (2) the affine transformation of a simplex is also a simplex. As PPI and N-FIND R algorithms, VCA also assumes the presence of pure pixels in the data. The algorithm iteratively projects data on to a direction orthogonal to the subspace spanned by the endmembers already determined. The new end member signature corresponds to the extreme of the projection. The algorithm iterates until all end members are exhausted. VCA performs much better than PPI and better than or comparable to N-FI NDR; yet it has a computational complexity between on e and two orders of magnitude lower than N-FINDR. The chapter is structure d as follows. Section 19.2 describes the fundamentals of the proposed method. Section 19.3 and Section 19.4 evaluate the proposed algorithm using simulated and real data, respectively. Section 19.5 presents some concluding remarks.

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El objetivo de este trabajo es desarrollar una aplicación web que sirva de gestión de los aparatos conectados a la centralita Asterisk y generar los ficheros de configuración, tanto para los terminales como para el correcto funcionamiento de la centralita. Además, se instalará un servidor que conecte centralita y Google Apps para que los usuarios puedan usar el videochat de Gmail como softphone, permitiéndoles enviar y recibir llamadas a través de la centralita de la universidad en cualquier parte del mundo.

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Actualment ens trobem en un món on tot gira al voltant de les noves tecnologies, i un pilar fonamental és l'oci i l'entreteniment. Això engloba principalment les indústries del cinema, videojocs i realitat virtual. Un dels problemes que tenen aquestes indústries és com crear l'escenari on es produeix la història. L'objectiu d'aquest projecte de final de carrera és crear una eina integrada al skylineEngine, que serveixi per crear edificis de manera procedural, on l'usuari pugui definir l'estètica d'aquest edifici, introduint la seva planta i els perfils adequats. El que s'implementarà serà una eina de modelatge per a dissenyadors, que a partir d'una planta i perfils pugui crear l'edifici.Aquest projecte es desenvoluparà a sobre del mòdul de generació d'edificis del skylineEngine, una eina pel modelatge de ciutats que s'executa sobre el Houdini 3D, que és una plataforma genèrica pel modelatge procedural d'objectes.El desenvolupament d'aquest projecte implica:• Estudi de la plataforma de desenvolupament Houdini 3D i de les llibreries necessàries per la incorporació de scripts Python. Estudi de les EEDD internes de Houdini.• Aprendre i manejar el llenguatge de programació Python.• Estudi del codi de l'article Interactive Architectural Modeling with Procedural Extrusions, per en Tom Kelly i en Peter Wonka, publicat a la revista ACM Transactions on Graphics (2011).• Desenvolupament d'algorismes de conversió de geometria d'una estructura tipus face-vertex a una de tipus half-edge, i viceversa.• Modificació del codi Java per acceptar crides sense interfície d'usuari i amb estructures de dades generades des de Python.• Aprendre el funcionament de la llibreria JPype per permetre enllaçar el Java dins el Python.• Estudi del skylineEngine i de les llibreries per la creació d'edificis.• Integració del resultat dintre del skylineEngine.• Verificació i ajust de les regles i paràmetres de la simulació per a diferents edificis

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Este proyecto busca analizar, diseñar e implementar una nueva solución de telefonía para el Centro Social de Oficiales de la Policía Nacional contemplando la posibilidad de optar por una migración hacia un sistema VoIP bajo software libre con Asterisk. En consecuencia, se deben evaluar las tecnologías actuales buscando proveer nuevas funcionalidades en el servicio telefónico generando bajos costos en su implementación, funcionamiento y mantenimiento.

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A new 3-D zinc phosphate, [C5N2H14][Zn-2(PO3(OH))(3)], has been synthesised under solvothermal conditions in the presence of 1-methylpiperazine. The structure, determined by single-crystal X-ray diffraction at 293 K (RMM = 520.9, orthorhombic, space group P2(1)2(1)2(1); a = 10.0517(2) &ANGS;, b = 10.4293(2) &ANGS; and c = 14.9050(5) &ANGS;; V = 1562.52 &ANGS;(3); Z = 4; R(F) = 2.60%, wR(F) = 2.93%), consists of vertex linked ZnO4 and PO3(OH) tetrahedra assembled into (4.8) net sheets which in turn are linked through further PO3(OH) units to generate a 3-D framework. 1-Methylpiperazinium cations reside within the 3-D channel system, held in place by a strong network of hydrogen bonds. The (4.8) net sheets occur in a number of zeolite structures e.g. ABW and GIS and related zinc phosphate phases. © 2004 Academie des sciences. Published by Elsevier SAS. All rights reserved.

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A new 3-D zinc phosphate, [C5N2H14][Zn-2(PO3(OH))(3)], has been synthesised under solvothermal conditions in the presence of 1-methylpiperazine. The structure, determined by single-crystal X-ray diffraction at 293 K (RMM = 520.9, orthorhombic, space group P2(1)2(1)2(1); a = 10.0517(2) &ANGS;, b = 10.4293(2) &ANGS; and c = 14.9050(5) &ANGS;; V = 1562.52 &ANGS;(3); Z = 4; R(F) = 2.60%, wR(F) = 2.93%), consists of vertex linked ZnO4 and PO3(OH) tetrahedra assembled into (4.8) net sheets which in turn are linked through further PO3(OH) units to generate a 3-D framework. 1-Methylpiperazinium cations reside within the 3-D channel system, held in place by a strong network of hydrogen bonds. The (4.8) net sheets occur in a number of zeolite structures e.g. ABW and GIS and related zinc phosphate phases. © 2004 Academie des sciences. Published by Elsevier SAS. All rights reserved.