1,721,271 research outputs found
Mass media e incendi forestali. Un’analisi preliminare applicata all’Umbria
No full textIn letteratura numerosi studi evidenziano come i media possono influenzare in maniera significativa tanto la percezione pubblica delle calamità naturali, quanto le modalità di reazione alle stesse. Con riferimento al fenomeno degli incendi forestali la ricerca sul ruolo dei mezzi di comunicazione di massa quali importanti strumenti per una corretta comprensione e reazione da parte del pubblico appare meno sviluppata rispetto a quanto disponibile in letteratura per altre tipologie di eventi. Il presente contributo rappresenta uno studio preliminare sulle possibili relazioni tra mezzi/modalità di comunicazione e incendi forestali con riferimento al territorio dell’Umbria e, in particolare, di cinque comuni (Terni, Arrone, Polino, Ferentillo e Montefranco) della Bassa Valnerina (Provincia di Terni). Si è realizzato un censimento dei media locali/regionali (carta stampata e televisione), seguito da una ricognizione delle notizie riportate dagli stessi e che abbiano fatto menzione a incendi boschivi nei mesi di giugno, luglio e agosto degli anni 2007 e 2012.
Le analisi di correlazione realizzate non evidenziano una sistematica relazione forte tra il fenomeno degli incendi in Umbria e l’attività dei mezzi di comunicazione considerati, siano essi quotidiani stampati o servizi di telegiornali televisivi.
Analisi di regressione preliminari hanno evidenziato che rispetto alle superfici bruciate la variabile esplicativa più significativa è rappresentata dalla durata degli incendi. E’ tuttavia degno di nota il fatto che la superficie sia influenzata anche dall’interazione tra durata degli incendi e lunghezza degli articoli pubblicati. Un’analisi qualitativa dei dati raccolti e presentati, infatti, evidenzia come l’attenzione dei media sembra essere condizionata dall’andamento dei fenomeni, con la tendenza ad aumentare la visibilità (numero di articoli/servizi, lunghezza e posizionamento degli stessi) in relazione alla frequenza degli incendi o alla loro dimensione in termini di superficie bruciata. Parimenti, se il riferimento alle cause degli incendi da parte dei mezzi di comunicazione non è comune, laddove presente si contraddistingue per una chiara prevalenza dei casi di incendio doloso. Da un lato ciò è in linea con i dati del Servizio Antincendio Boschivo - anche su scala nazionale - dall’altro risponde forse anche alla maggiore attrattività di questi aspetti nei confronti del pubblico. Il rischio, in questo caso, è però di incorrere in una lettura distorta del fenomeno degli incendi da parte dell’opinione pubblica
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
Peridynamic modelling and experimental verification of nanocomposite properties
No full textNanomodified epoxy resins have recently attracted the interest of the scientific community, since the
addition of low concentrations of nanofillers results in enhanced mechanical, thermal and barrier
properties. Modelling the mechanical properties of nanocomposites is of key importance to increase
their reliability and expand their application fields. In this work, a peridynamics-based representative
volume element model is implemented to estimate the effective tensile properties of nanocomposites. The
newly developed algorithm allows to model randomly distributed nanofillers with different sizes, shapes,
and orientations, and enables the simulation of interphase properties and nanofiller agglomerations.
Numerical results are validated by performing tensile tests on specimens composed by epoxy resin
nanomodified through the addition of montmorillonite clays. The versatility of the model is proved by a
further comparison of the computed results with experimental data reported in literature
Vegetables inhibit, in vivo, the mutagenicity of nitrite combined with nitrosable compounds
No full textNo abstract availabl
- …
