146,031 research outputs found
La città e le mura: nuovi dati dall’area Nord della città antica
No full textThis paper deals with the excavations held by the University of Napoli "L'Orientale" in the urban area and the Northern walls of Cumae in Campania. The excavations in the urban area, directed by Matteo D'Acunto, found layers going back as early as the early archaic and archaic periods. They found part of a house which was established in the second half of the 8th Cent. BC with a well preserved series of hearth
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Analysis and design of CMOS and bipolar SiGe:C integrated circuits for low power RF receivers and radar applications
No full textThis dissertation proposes the analysis and the design of two radio-frequency integrated circuits.
In the first part a low-power wireless receiver front-end for Wireless Sensor Networks is developed. The circuit comprises a Low-Noise Amplifier, Voltage Controlled Oscillators and Mixers, building a complete single-stage quadrature receiver front-end for low-power applications. The compact architecture based on a current reuse topology is described and motivated; an in-depth time-variant analysis is performed to optimize the circuit; a test 2.4GHz receiver is finally designed and realized in a cheap 90nm CMOS technology with a 3μm thick top metal for high-quality integrated inductors. Measurement results confirm the correctness of our analysis and the validity of the proposed circuit architecture.
In the second part of this dissertation a X-band upconverter for a Frequency-Modulated Continuous-Wave radar system is developed. The goal of the project is that of developing a wideband upconverter with a clean output spectrum and low phase noise. The proposed architecture is constituted by two mixers, baseband interfaces, a pre-power amplifier and the on-chip circuitry to generate quadrature local oscillator signals from an external reference local oscillator. Several mechanisms which lead to spurious tones at the output are discussed, with emphasis on the design issues related to the image-rejection, the mismatches and the nonlinearities in the large-signal baseband interface.
Two versions of the modulator are designed and compared: a) a CMOS version built in a 65nm digital technology based on a zero DC current passive mixer for minimum flicker noise and b) a bipolar version built in a 0.35μm SiGe:C technology based on an active Gilbert mixerQuesta tesi di dottorato propone l'analisi e la progettazione di due circuiti integrati a radio-frequenza.
Nella prima parte del lavoro viene sviluppato il front-end di un ricevitore wireless a basso consumo di potenza per Wireless Sensor Networks. Il circuito, che comprende un amplificatore a basso rumore, oscillatori locali e mixer, costituisce un sistema di ricezione completo implementato in un singolo stadio per ridurre il consumo di potenza.
L'architettura proposta, basata sulla tecnica del riutilizzo della corrente di polarizzazione, viene motivata e descritta in dettaglio; segue un'accurata analisi tempo-variante dell'architettura per l'ottimizzazione del circuito proposto; il ricevitore a 2.4GHz è stato infine realizzato con una tecnologia CMOS digitale a 90nm con top metal ottimizzato per la realizzazione di induttori integrati con alto fattore di qualità. Le misure effettute sui campioni confermano la correttezza della nostra analisi e la validità dell'architettura proposta.
Nella seconda parte di questa tesi di dottorato viene sviluppato un upconverter per un Frequency-Modulated Continuous-Wave radar in banda X. L'obiettivo del progetto è quello di realizzare un upconverter a banda larga, con uno spettro in uscita libero da toni spuri e con minimo phase noise. L'architettura proposta comprende due mixer con relative interfacce in banda base, un amplificatore a radiofrequenza e tutta la circuiteria per la generazione dei segnali in quadratura per pilotare i mixer a partire da un oscillatore locale esterno di riferimento.
Vengono analizzati vari meccanismi di generazione di toni spuri all'uscita, con particolare enfasi sui problemi legati alla reiezione dell'immagine, ai mismatches ed alle nonlinearità generate nell'interfaccia in banda base.
Due versioni del modulatore sono state progettate e confrontate: a) una versione realizzata in una tecnologia CMOS a 65nm digitale basata su un mixer passivo a corrente di polarizzazione nulla per minimizzare la generazione di rumore flicker e b) una versione realizzata in una tecnologia bipolare SiGe:C a 0.35μm basata su un mixer di Gilbert attiv
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Correction to: Intra-ligamentary autologous conditioned plasma and healing response to treat partial ACL ruptures (Archives of Orthopaedic and Trauma Surgery, (2018), 138, 5, (675-683), 10.1007/s00402-018-2885-1)
No full textWith regards to Berardo Di Matteo, second author. The author's name is incorrectly listed on Pub-Med. The first and last name have been mixed up
[Book Review] Teaching the History of the Book, edited by Matteo Pangallo and Emily B. Todd
No full textBook review of Teaching the History of the Book, edited by Matteo Pangallo and Emily B. Todd. 
Effects of induction interactions on the orientational order of solutes in liquid crystals
No full textIn a recent paper (di Matteo, A.; Ferrarini, A.; Moro, G. J. J. Phys. Chem. B 2000, 104, 7764) a method to derive a mean field potential for molecules in nematic phases based on their structure and charge distribution has been presented. The potential consists of a shape and a reaction field contribution, accounting for short range and electrostatic intermolecular interactions, respectively. The model is extended here by introducing induction interactions in the reaction field. In the spirit of our approach, aimed at a realistic picture at a semiphenomenological level, an appropriate description is obtained in terms of distributed polarizabilities. The Thole model of interacting damped atom dipoles has been singled out as a suitable one, although also different choices have been considered. The orientational order parameters calculated in this way for a set of typical polar and nonpolar solutes in nematic solvents are reported, and the influence of induction interactions is discussed
ASPETTANDO per strumenti a tastiera acustici, elettronici, informatici di Matteo Segafreddo
No full textLa composizione ASPETTANDO evidenzia musicalmente due dimensioni distinte espresse dal Cristo [B] e dall’artista bulgaro Christo Vladimirov Javacheff [A], attraverso una grafica musicale specifica delle immagini poetico-testuali.
Queste due dimensioni sono contestualmente sintetizzate da un’articolazione musicale “polarizzante” ed indicativa nel titolo "Aspettando". Esse corrispondono esteticamente alla spazializzazione e all’astrattismo sonoro-gestuale delle fluttuazioni timbriche di ogni singolo evento poetico-artistico-musicale.
Il brano impiega una grafica sonora “aleatorio-strutturata” ed articola i vari elementi linguistici in un'unità stilistica dell’intero percorso compositivo.
Il lavoro è eseguibile attraverso tutti gli strumenti a tastiera: acustici, elettronici ed informatici
Supporting data for the paper "Efficient white noise sampling and coupling for multilevel Monte Carlo with non-nested meshes"
No full textThe attached files contain the supporting data for the paper "Efficient white noise sampling and coupling for multilevel Monte Carlo with non-nested meshes" by Matteo Croci, Michael B. Giles, Marie E. Rognes and Patrick E. Farrell, as accepted in SIAM/ASA Journal on Uncertainty Quantification on 09 September 2018.
See README file for additional information regarding the data
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