5,978 research outputs found

    A Study of e+e- -> H0A0 -> bbbb at 3 TeV at CLIC

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    The precise determination of the masses of the CP-odd and -even heavy Higgs bosons is an important part of the study of Supersymmetry and its relation with cosmology through dark matter. This note presents a determination of the A0 boson mass with the e+e- -> H0A0 -> b b b b process for a dark matter motivated cMSSM scenario with M(A) = 1141 GeV at CLIC. The analysis is performed with full simulation and reconstruction at 3 TeV accounting for beamstrahlung effects. SM and SUSY backgrounds are considered and the effect of the overlay of gamma gamma -> hadrons events on the signal is studied for various assumptions for the detector time-stamping capabilities. The di-jet mass resolution is improved by applying a kinematic fit. The A0 mass can be determined with a statistical accuracy of ~3-5 GeV for 3 inverse ab of statistics and 0 to 20 bunch crossings of gamma gamma background integrated in one event, respectively.Comment: 11 pages, 4 figure

    Gravitational waves emitted by extrasolar planetary systems

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    In this paper we consider the Extra-solar Planetary Systems recently discovered in our Galaxy as potential sources of gravitational waves. We estimate the frequency and characteristic amplitude of the radiation they emit due to the orbital motion, using the quadrupole formalism. In addition, we check whether the conditions needed for the resonant excitation of the f- and g-modes of the central star can be fulfilled. By a Roche-lobe analysis, we show that there could exist systems in which the low-order g-modes could be excited, although this does not happen in the systems discovered up to now.Comment: 14 pages, 5 figures. Accepted for publication on International Journal of Modern Physics D. Table 6 and minor typos correcte

    Disseny per a edició digital: l'experiència de Domus

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    En los últimos años, uno de los fenómenos más relevantes que está emergiendo como línea de desarrollo en el ámbito de la edición en línea es la búsqueda de una experiencia de lectura lo más fluida posible en diferentes soportes y dispositivos. A pesar de la rápida proliferación de ediciones en iPad de muchas revistas y periódicos, la tendencia dominante parece buscar, en lugar de "layouts" específicos para cada soporte, un código que se pueda adaptar a las dimensiones físicas de los diferentes dispositivos. La historia del nacimiento de la edición digital de la revista "Domus" puede ofrecer una interesante aproximación en esta época concreta de cambio y evolución.In recent years one of the most relevant fields of development in online publications is the search for new supports and devices that will enable reading experiences to be as smooth and free-flowing as possible. In spite of the swift proliferation of iPad editions of many magazines and newspapers, theprevailing trend seems not favour the idea of specific layouts for each support, but rather to find a code that may be adapted to the physical dimensions of the different devices. The story of the birth of the digital edition of the review Domus offers an interesting perspective of this specific period of evolution and change.En aquests darrers anys, un dels fenòmens més rellevants que està sorgint com a línia de desenvolupament en el camp de l'edició en línia és la recerca d'una experiència de lectura el més fluïda possible en diferents suports i dispositius. Malgrat la ràpida proliferació d'edicions iPad de moltes revistes i diaris, la tendència dominant sembla buscar, en lloc de "layouts" específics per a cada suport, un codi que es pugui adaptar a les dimensions físiques dels diferents dispositius. La història del naixement digital de la revista "Domus" pot oferir una interessant aproximació a aquesta etapa concreta de canvi i evolució

    Retirement Systems, Demography, Happiness and Welfare Redistribution

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    This research investigates whether an equity improvement within retirement-systems domain may positively influence demography, people’s happiness and their financial conditions. In particular, a fertility-boosting policy has been tested, acting on the contributory rate. This project has been carried out by using software simulation and with specific Agent-based Computational Economics (ACE) methodology. Two virtual worlds have been created, in order to try to reproduce Italian society. In the first model, (W1), vertical equity has been improved, while in the second one, (W2), it is has not. Five further variants of these two worlds have been produced by altering some parameters, in order to test our hypothesis through several simulations. The research outcomes prove that an equity improvement can positively influence demographic trends, can increase the level of happiness in the society, and can grant a more homogeneous welfare redistribution.Retirement systems, demography, happiness, wealth distribution, equity, software simulation, Agent Based Computational Economics

    The Bus Goes Wireless: Routing-Free Data Collection with QoS Guarantees in Sensor Networks

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    Abstract—We present the low-power wireless bus (LWB), a new communication paradigm for QoS-aware data collection in lowpower sensor networks. The LWB maps all communication onto network floods by using Glossy, an efficient flooding architecture for wireless sensor networks. Therefore, unlike current solutions, the LWB requires no information of the network topology, and inherently supports networks with mobile nodes and multiple data sinks. A LWB prototype implemented in Contiki guarantees bounded end-to-end communication delay and duplicate-free, inorder packet delivery—key QoS requirements in many control and mission-critical applications. Experiments on two testbeds demonstrate that the LWB prototype outperforms state-of-theart data collection and link layer protocols, in terms of reliability and energy efficiency. For instance, we measure an average radio duty cycle of 1.69 % and an overall data yield of 99.97 % in a typical data collection scenario with 85 sensor nodes on Twist. I

    SURGICAL NAVIGATION AND AUGMENTED REALITY FOR MARGINS CONTROL IN HEAD AND NECK CANCER

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    I tumori maligni del distretto testa-collo rappresentano un insieme di lesioni dalle diverse caratteristiche patologiche, epidemiologiche e prognostiche. Per una porzione considerevole di tali patologie, l’intervento chirurgico finalizzato all’asportazione completa del tumore rappresenta l’elemento chiave del trattamento, quand’anche esso includa altre modalità quali la radioterapia e la terapia sistemica. La qualità dell’atto chirurgico ablativo è pertanto essenziale al fine di garantire le massime chance di cura al paziente. Nell’ambito della chirurgia oncologica, la qualità delle ablazioni viene misurata attraverso l’analisi dello stato dei margini di resezione. Oltre a rappresentare un surrogato della qualità della resezione chirurgica, lo stato dei margini di resezione ha notevoli implicazioni da un punto di vista clinico e prognostico. Infatti, il coinvolgimento dei margini di resezione da parte della neoplasia rappresenta invariabilmente un fattore prognostico sfavorevole, oltre che implicare la necessità di intensificare i trattamenti postchirurgici (e.g., ponendo indicazione alla chemioradioterapia adiuvante), comportando una maggiore tossicità per il paziente. La proporzione di resezioni con margini positivi (i.e., coinvolti dalla neoplasia) nel distretto testa-collo è tra le più elevate in ambito di chirurgia oncologica. In tale contesto si pone l’obiettivo del dottorato di cui questa tesi riporta i risultati. Le due tecnologie di cui si è analizzata l’utilità in termini di ottimizzazione dello stato dei margini di resezione sono la navigazione chirurgica con rendering tridimensionale e la realtà aumentata basata sulla videoproiezione di immagini. Le sperimentazioni sono state svolte parzialmente presso l’Università degli Studi di Brescia, parzialmente presso l’Azienda Ospedale Università di Padova e parzialmente presso l’University Health Network (Toronto, Ontario, Canada). I risultati delle sperimentazioni incluse in questo elaborato dimostrano che l'impiego della navigazione chirurgica con rendering tridimensionale nel contesto di procedure oncologiche ablative cervico-cefaliche risulta associata ad un vantaggio significativo in termini di riduzione della frequenza di margini positivi. Al contrario, le tecniche di realtà aumentata basata sulla videoproiezione, nell'ambito della sperimentazione preclinica effettuata, non sono risultate associate a vantaggi sufficienti per poter considerare tale tecnologia per la traslazione clinica.Head and neck malignancies are an heterogeneous group of tumors. Surgery represents the mainstay of treatment for the large majority of head and neck cancers, with ablation being aimed at removing completely the tumor. Radiotherapy and systemic therapy have also a substantial role in the multidisciplinary management of head and neck cancers. The quality of surgical ablation is intimately related to margin status evaluated at a microscopic level. Indeed, margin involvement has a remarkably negative effect on prognosis of patients and mandates the escalation of postoperative treatment by adding concomitant chemotherapy to radiotherapy and accordingly increasing the toxicity of overall treatment. The rate of margin involvement in the head and neck is among the highest in the entire field of surgical oncology. In this context, the present PhD project was aimed at testing the utility of 2 technologies, namely surgical navigation with 3-dimensional rendering and pico projector-based augmented reality, in decreasing the rate of involved margins during oncologic surgical ablations in the craniofacial area. Experiments were performed in the University of Brescia, University of Padua, and University Health Network (Toronto, Ontario, Canada). The research activities completed in the context of this PhD course demonstrated that surgical navigation with 3-dimensional rendering confers a higher quality to oncologic ablations in the head and neck, irrespective of the open or endoscopic surgical technique. The benefits deriving from this implementation come with no relevant drawbacks from a logistical and practical standpoint, nor were major adverse events observed. Thus, implementation of this technology into the standard care is the logical proposed step forward. However, the genuine presence of a prognostic advantage needs longer and larger study to be formally addressed. On the other hand, pico projector-based augmented reality showed no sufficient advantages to encourage translation into the clinical setting. Although observing a clear practical advantage deriving from the projection of osteotomy lines onto the surgical field, no substantial benefits were measured when comparing this technology with surgical navigation with 3-dimensional rendering. Yet recognizing a potential value of this technology from an educational standpoint, the performance displayed in the preclinical setting in terms of surgical margins optimization is not in favor of a clinical translation with this specific aim

    Low-Noise Charge Preamplifier for Electrostatic Beam Position Monitoring Sensor at the ELENA Experiment

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    AbstractThe Extra Low ENergy Antiproton ring (ELENA) is a synchrotron under construction at CERN aimed to decelerate the antiprotons from the existing Antiproton Decelerator (AD) to an energy of 100 keV. The orbit measurement of the beam is accomplished by 20 electrostatic Beam Position Monitoring (BPM) sensors to measure complete orbits every 20ms with a resolution of 0.1mm for intensities in the range of 1-3×107 charges. For the conditioning of the pick-up signals from the BPMs a low-noise charge amplifier has been purposely designed and is under testing. The circuit must feature a bandwidth of 40MHz and an equivalent input voltage noise spectral density of 0.4 nV/√Hz for a sensor capacitance CS of about 26 pF. After amplification, the sum and difference signals are analogically derived and sent over 50 m cables to further blocks for digitalization and processing
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