1,720,967 research outputs found
BAYES INFERENCE IN MULTICRITERIA ANALYSIS FOR HYBRID ELECTRICAL TRANSPORTATION SYSTEMS DESIGN
No full text
The Role Of Availability Parameters For The Choice Of Stand-Alone Power Plants
No full textThe paper tackles the problem of the optimal sizing of a wind power system at the planning stage, consisting in the best choice among many alternatives-as a function of reliability and maintenance, both encompassed in the availability function of the system. Moreover, statistical methods to deal with uncertainty of such parameters are also discussed and illustrated with reference to typical values of wind turbines. In particular, the case studies refer to the sizing of generation capability of a power system, that consists in the choice of the optimal number and size of the generators (assumed as having all the same size and availability) to be installed for a given total installed power. The results show that the solution that features the highest availability might not be also the best in terms of expected performances, evaluated e.g. as expected energy not supplied. Finally, some numerical applications are illustrated regarding a new statistic methodology for handling the unavoidable randomness of the above availability parameters, in order to perform a rational choice among different alternatives
Affidabilità e Manutenzione nel Progetto Ottimale dei Sistemi Elettrici
No full textNel lavoro viene trattato il problema del dimensionamento
ottimale di un sistema elettrico per l’energia (SEE) in fase
di pianificazione – ovvero della migliore scelta tra più
alternative progettuali - in funzione della affidabilità e
della manutenzione, inglobate nella funzione “disponibilità”
del sistema.
In particolare, nelle esemplificazioni viene fatto riferimento
al dimensionamento della generazione di un SEE,
che consiste in pratica nella scelta del numero e della taglia
dei generatori da installare (supposti della stessa taglia
e disponibilità), per una data potenza totale installata.
I risultati mostrano che non sempre la soluzione avente
maggiore disponibilità risulta la migliore anche in termini
di prestazioni “attese”, misurate ad esempio in termini
di carico non fornito. Ciò mostra l’importanza di introdurre
adeguati “indici di rischio” per caratterizzare le
prestazioni globali del sistema; inoltre, sotto opportune
ipotesi, gli indici discussi sono esprimibili analiticamente
in termini dei parametri caratteristici della affidabilità e
della manutenzione, il che consente di effettuare una opportuna
analisi di sensitività degli stessi indici rispetto ai
parametri
Sistemi Elettrici con Sorgenti Fotovoltaiche per l'Alimentazione di carichi Intermittenti
No full text
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
- …
