1,720,987 research outputs found
IL RUOLO DEI TRASPORTI NELLA PROGRAMMAZIONE DEL MEZZOGIORNO
No full textIl libro, di cui i curatori sono anche autori di alcuni capitoli, riferisce i risultati di una ricerca che il Ministero del Bilancio e della Programmazione Economica ha affidato alla Società Italiana dei Docenti di Trasporti in merito alla valutazione del ruolo svolto dal settore trasporti nel sistema economico e sociale dell'area del Mezzogiorno d'Italia.
L'indagine è stata finalizzata a verificare le possibili deviazioni ed anomalie verificatesi nel tempo fra la programmazione nazionale, a partire dal secondo dopoguerra, ed i risultati conseguiti sul piano reale, con la conseguente possibilità di individuare profili correttivi utili per un'opportuna attività di programmazione futura
CONVENZIONE SULLE RELAZIONI FUNZIONALI TRA ATTIVITA', INFRASTRUTTURE E FLUSSI
No full textIl volume presenta i risultati di una convenzione di ricerca finalizzata ad analizzare le relazioni funzionali tra i flussi (di mobilità, energia, rifiuti, telecomunicazioni, etc) e gli insediamenti sul territorio.
Lo studio di tali relazioni è considerato nella ricerca preliminare alla definizione delle linee fondamentali dell'assetto del territorio antro cui inquadrare gli interventi di sviluppo economico e di salvaguardia ambientale di responsabilità del Ministero dei Lavori Pubblici
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
IEEE 802.11 Ad Hoc Networks: Performance Measurements
No full textIn this paper we investigate the performance of IEEE 802.11b ad hoc networks by means of an experimental study. An extensive literature, based on simulation studies, there exists on the performance of IEEE 802.11 ad hoc networks. Our analysis reveals several aspects that are usually neglected in previous simulation studies. Firstly, since different transmission rates are used for control and data frames, different transmission ranges and carrier-sensing ranges may exist at the same time in the network. In addition, the transmission ranges are in practice much shorter than usually assumed in simulation analysis, not constant but highly variable (even in the same session) and depends on several factors. Finally, the results presented in this paper indicate that for correctly understanding the behavior of an 802.11b
network operating in ad hoc mode, several different ranges must be considered. In addition to the transmission range, the physical carrier
sensing range is very important. The transmission range is highly dependent on the data rate and is up to 100 m, while the physical carrier sensing range is almost independent from the data rate and is approximately 200 m. Furthermore, even though stations are outside from
their respective physical carrier sensing range, they may still interfere if their distance is lower than 350 m
La mobilité urbaine au service d’événements exceptionnels: le plan de l’agence pour la preparation du jubilé pour la XV journée mondiale de la jeunesse de l’an 2000
No full textLa memoria riassume la costruzione dei modelli matematici necessari alla simulazione ed alla gestione dei flussi di domanda in occasione di grandi eventi di massa.
I modelli costruiti sono stati calibrati attraverso lo studio della XV Giornata Mondiale della Gioventù, organizzata a Roma in occasione del Giubileo dell'anno 2000
Understanding the Real Behavior of 802.11 and Mote Ad hoc Networks
No full textIEEE 802.11 and Mote devices are today two of the most interesting wireless technologies for
ad hoc and sensor networks respectively, and many efforts are currently devoted to understanding
their potentialities. Unfortunately, few works adopt an experimental approach, though several
papers highlight that popular simulation and analytical approximations may lead to very inaccurate
results. In this paper we discuss outcomes from an extensive measurement study focused on these
technologies. We analyze the dependence of the communication range on several parameters, such
as node distance from the ground, transmission data rate, environment humidity. Then, we study the
extent of the physical carrier sensing zone around a sending node. On the basis of these elements, we
provide a unified wireless link model for both technologies. Finally, by using this model we analyze
well-known scenarios (such as the hidden node problem), and we modify the traditional formulations
according to our experimental results
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