1,721,043 research outputs found
Sviluppo e test dell'elettronica di front-end per i fototubi a grande dimensione dell'esperimento JUNO
Full text linkUna delle grandi sfide riguardanti la fisica del neutrino riguarda l'identificazione della sua gerarchia di massa. Il Jiangmen Underground Neutrino Observatory (JUNO) e' un rivelatore a scintillatore liquido di nuova generazione, determinato a trovare una risposta a questa questione ancora irrisolta rilevando anti-neutrini elettronici da reattore, generati da centrali nucleari poste ad una distanza di circa 50 km, con una risoluzione energetica senza precedenti del 3% @ 1 MeV, grazie ad una immensa massa bersaglio di 20 mila tonnellate di liquido scintillatore, attorniato da circa 18'000 tubi fotomoltiplicatori (PMT) di grandi dimensioni, il tutto immerso in una piscina d'acqua a circa 700 metri di profondita'. La tesi introduce la fisica riguardante l'oscillazione del neutrino in vuoto, fenomeno sfruttato da JUNO per studiare il problema della gerarchia di massa. Successivamente vengono introdotte le principali interazioni del neutrino con il rivelatore, incentrandosi sulla reazione di inverse beta decay per la rilevazione di anti-neutrini elettronici. In questa sezione vengono spiegate anche le differenti sorgenti di neutrini che l'esperimento JUNO rilevera' e il segnale di fondo atteso, oltre al vasto programma di fisica del neutrino di JUNO verra' descritto. Successivamente verra' descritta l'elettronica di front-end. Una risoluzione di 0.1 fotoelettroni e una finestra di sincronizzazione di 16 ns sono solo alcune delle caratteristiche necessarie a raggiungere i requisiti di JUNO. Da qui nasce il concetto della Global Control Unit (GCU): una scheda custom a bassa potenza, sviluppata da Universita' e INFN di Padova, capace di svolgere differenti funzioni, dalla trasmissione di dati alla loro analisi, grazie all'intelligenza garantita da un Field Programmable Gate Array (FPGA), un circuito integrato configurabile dopo produzione, presente su scheda. La GCU verra' inoltre posizionata molto vicina ai PMT, sott'acqua, per evitare qualsiasi possibile degradazione del segnale causato da una grande lunghezza dei cavi. Dopo la descrizione della scheda, la configurazione della sua FPGA (chiamato comunemente firmware) e la sua caratterizzazione, le funzionalita' della GCU vengono testate su di un piccolo rivelatore a scintillatore liquido a modello JUNO, con installati 48 PMT. Il rivelatore si trova ai Laboratori Nazionali di Lgnaro (INFN-LNL) ed e' stato progettato da Universita'/INFN Padova. Dopo una breve descrizione dell'apparato, vengono mostrati i risultati ottenuti utilizzando l'elettronica di readout di JUNO. La realizzazione di questo rivelatore e' stata cruciale, in quanto ha permesso di testare l'elettronica di JUNO su di un vero setup multicanale, acquisendo esperienza chiave per poi la successiva installazione sul rivelatore finale.One of the many challenges neutrino physics is facing is the neutrino's mass hierarchy determination. The Jiangmen Underground Neutrino Observatory (JUNO) is a new generation Liquid Scintillator (LS) detector, determined on answering this question by detecting reactor electron anti-neutrinos generated from nuclear power plants at a medium baseline, around 50 km, featuring an unprecedent energy resolution of 3% @ 1 MeV, thanks to a 20 kton of LAB LS surrounded by about 18'000 20 inches Photo Multiplier Tubes (PMT), all immersed in a water pool about 700 m underground. The thesis introduces the physics of neutrinos flavor oscillation, as vacuum oscillations are exploited by JUNO to tackle the neutrinos mass hierarchy problem. Neutrino interactions with the JUNO detector are then explained, focusing on the inverse beta decay reaction for reactor anti-neutrino detection. The correlated background together with the different neutrino's sources for JUNO and its broad physics program are further described. Afterwards, the front-end electronics to achieve JUNO's demanding requirements are investigated. An energy resolution of 0.1 photoelectron and a 16 ns window timing synchronization are just some of the necessary specifications to reach the challenging target. Hence, the concept of the Global Control Unit (GCU) has been introduced: a custom and low power hardware platform, developed by INFN-Padova/University of Padova, with intelligence on board, able to perform several different tasks such as selective readout and transmission, placed very close to the PMTs to avoid any degradation of the signals caused by long cables. The intelligence is provided by a Field Programmable Gate Array (FPGA), which is an integrated circuit, configurable after manufacturing. After a description of the board, its FPGA configuration (commonly called firmware) implementation and its characterization, the GCUs functionalities have been tested on a small JUNO mock-up LS detector featuring 48 PMTs, located at the INFN National Laboratories of Legnaro and designed by the Padova JUNO group. After a brief description of the apparatus, the results obtained using the JUNO readout electronics are shown. The realization of such detector has been crucial in order to test the electronics on a real LS detector and be prepared for its final deployment in JUNO
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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