1,721,211 research outputs found
Combining semilattices and semimodules
No full textWe describe the canonical weak distributive law δ: SP → PS of the powerset monad P over the S-left-semimodule monad S, for a class of semirings S. We show that the composition of P with S by means of such δ yields almost the monad of convex subsets previously introduced by Jacobs: the only difference consists in the absence in Jacobs’s monad of the empty convex set. We provide a handy characterisation of the canonical weak lifting of P to EM(S) as well as an algebraic theory for the resulting composed monad. Finally, we restrict the composed monad to finitely generated convex subsets and we show that it is presented by an algebraic theory combining semimodules and semilattices with bottom, which are the algebras for the finite powerset monad Pf
Transparent gap filler solution over a DVB-RCS2 satellite platform in a railway scenario: Performance evaluation study
No full textIn this work, a performance study of a system equipped with a transparent Gap Filler solution in a DVB-RCS2 satellite platform has been provided. In particular, a simulation model based on a 3-state Markov chain, overcoming the blockage status through the introduction of a transparent Gap Filler (using devices on both tunnel sides) has been implemented. The handover time, due to switching mechanism between satellite and Gap Filler, has been taken into account. As reference scenario, the railway market has been considered, which is characterized by a N-LOS condition, due to service disruptions caused by tunnels, vegetation and buildings. The system performance, in terms of end-to-end delay, queue size and packet loss percentage, have been evaluated, in order to prove the goodness of communications in a real railroad path
RFI: il caso studio della stazione GNSS dell’Università di Palermo
No full textLa sperimentazione descritta in questo lavoro riguarda la prima parte di una ricerca, tuttora in corso, che vede coinvolti l’Agenzia Regionale Protezione Ambiente Sicilia (ARPA) e il Dipartimento di Rappresentazione dell’Università di Palermo (DIRAP), avente come tema le problematiche relative alle interferenze da radio frequenza registrate dalla stazione permanente GNSS dell’Università di Palermo. La stazione è stata materializzata nel 2006 e dal 2007 fa parte della rete di stazioni permanenti GNSS-NRTK gestita dal DIRAP, per attività di studio di ricerca.
In particolare, in questo lavoro sono illustrati i test che sono stati condotti e i risultati in termini di interferenza elettomagnetica
RFI: a case study of the University of Palermo
No full textThe work shows the results of testing conducted from last years with the GNNS CORS of University of Palermo, in term of radio frequency interference, by a team composed of researchers of Dipartimento di Rappresentazione (DIRAP), Faculty of Engineering of Palermo and to the Laboratory of Physics of the Agenzia Regionale per la Protezione dell’Ambiente (ARPA) of the Sicilian Region. The CORS is first installed inside a scientific network with 9 permanent station located in western Sicily with distance between 22 and 80 kilometres and carry out for real time positioning experience. The main goal of the work is to verify the radio frequency interference which has been subjected CORS in last years.
The methodological approach consists of several measures of electromagnetic field, supported by the analysis of raw data with scientific software (TEQC, QC2SKY, NDA)
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
MONITORAGGIO DINAMICO DEI CAMPI ELETTROMAGNETICI NELLE AREE URBANE: PROBLEMATICHE E CASI STUDIO
No full textMessa a punto di una procedura teorico-sperimentale per la misura dell'impatto vibrazionale dovuto al traffico veicolare sugli edifici di interesse storico-artistico.
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