1,721,012 research outputs found
Design techniques of two-layer architectures for WDM optical networks
No full textA general method for designing multilayered WDM optical networks, based on the combined use of single- and multi-hop connection modes, is presented. It takes into account variable values for the number of users and wavelengths in each cluster. Closed form expressions are derived for the transmission capacity and the optimum number of channels for intra-cluster communications, either in the case of uniform or non-uniform traffic distribution. The analytical approach is particularly useful in the presence of constraints on the number of wavelengths, due to technological limits or non-linear phenomena, when sub-optimal solutions must be necessarily addressed. The proposed method is integrated with the adoption of well-known selection procedures, like simulated annealing or genetic algorithms, to reduce the computational effort
Space division architectures for crosstalk reduction in optical interconnection networks
No full textSperimentazione di impianti a portata variabile per la climatizzazione di sale operatorie
No full textIn questo lavoro vengono descritti i primi risultati ottenuti su un modello sperimentale, "full scale" di una sala operatoria climatizzata mediante un impianto a portata variabile a tutt'aria esterna, controllato da un sistema di supervisione ed acquisizione ed elaborazione dati. La variazione della portata è correlata alle misure di concentrazione di un gas tracciante, immesso in ambiente da un apposito sistema di rilascio, che simula la presenza di gas anestetici derivanti dalle attività condotte dallo staff operatorio.La conformazione architettonica ed impiantistica della sala in prova possono essere variate a piacere, in modo da poter riprodurre esattamente in scala reale le tipologie utilizzate nelle diverse realtà ospedaliere. Il sistema di prova così costruito è in grado di simulare fenomeni di inquinamento ambientale di qualunque natura e di studiare gli effetti di diffusione, accumulo e rimozione all'interno del volume di controllo, in dipendenza delle caratteristiche prestazionali e componentistiche dell'impianto di condizionamento dell'aria
Energy Savings and dynamical Control of HVAC Systems in operating Theatre: an Experimental Approach
No full textIn this paper the problem of anaesthetic gases dilution in operating theatres has been examined, by experiences carried out in a full scale testing room. The performance of two different HVAC plants have been compared, one of them working in static conditions at 20 external air changes per hour, whereas the other has been dynamically driven by an automatic control system between 10 and 20 external air changes per hour. In the latter case, the flow control operate as a function of the concentration level of tracer gas, simulating a pollutant, sampled in real time by a suitable monitoring system. The results demonstrate that a dynamic HVAC system can guarantee good environmental conditions and satisfactory comfort, as well as remarkable energy savings
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
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