1,720,956 research outputs found
Road pollution analysis dynamic model (ropadym)
No full textThe pollutant diffusion adjacent to the motorway is strongly influenced by the vehicle induced turbulence. In spring 2001, turbulence measures were carried out in order to evaluate the phenomena intensity and range on the motorway from Mannheim to Heidelberg. It was found that the vehicle induced turbulence has more energy than the natural atmospheric turbulence until a distance of 40-50 meters from the motorway under particular meteorological conditions. Many attempts to create models and mathematical formulas for pollutant concentration distribution evaluations are found in the relevant technical literature. These limit the analysis to two dimensional urban U-sections without taking into account the vehicular transmitted energy to the air. The Road Pollution Analysis using the three dimensional Dynamic Models (ROPADYM). implemented with computational fluid dynamics (CFD) codes which take into account the vehicular motion and consequently the vehicular traffic induced Turbulent Kinetic Energy (TKE). With this approach more accurate pollutant distributions evaluations and predictions in the proximity of road infrastructures is done. This infrastructure can be urban or suburban, a U-section, a tunnel or a discontinuity (e.g. tunnel fornix). ROPADYM models are implemented with the “sliding mesh” technique that allows a faster calculation with a high level definition compared to adaptive mesh techniques. Case studies are worked out and a comparison is given with two dimensional classical approaches
Misura e mitigazione dell’impatto ambientale da traffico veicolare in galleria
No full textThe volumes of a road tunnel including the tunnel exits, affected by the plume effect were analysed by an original numerical simulation model named RO.P.A.DY.M. (ROad Pollution Analysis DYnamic Model). This model was developed by taking into account the fluid-dynamic effects of road-vehicle motion in order to carry out the map of atmospheric pollutant concentrations within the foregoing volumes in near-to-real conditions. With the use of an innovative CFM method (Control Function Method) an objective measure of the environmental impact of road traffic for the foregoing volumes was obtained. The introduction of air-cleaning active systems in the tunnel and at the exits was considered. With the application of the ROPADYM model pollutant concentration maps were produced for the volumes considered in the tunnel, taking into account the cleansing systems. In conclusion, a quantitative evaluation of the effects obtained from the application of these active systems was formulated. This evaluation is expressed for the reduction in both pollutant concentrations and environmental impact
Molte proprietà semplici individuate e dimostrate dagli studenti attraverso ragionamenti concreti simili a quelli naturali. Scelta e uso dei simboli. Sviluppo dell'autostima degli studenti
No full textAttività preliminare svolta nel Laboratorio "Saper ultravedere" nello spazio, inserito nel Progetto Nazionale Lauree Scientifiche
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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
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