1,721,023 research outputs found
Scale model investigation on the influence of boundary conditions on the airborne sound insulation of lightweight double walls
No full textSound reduction index measurements were performed inside a 1:10 scale model of two adjoining rooms of a test facility in an acoustic laboratory, with the aim of investigating the influence of the boundary conditions on the acoustic performance of lightweight double walls. The model was built entirely of polymethyl methacrylate (PMMA). The specimen double walls were built using the same acrylic material. At first, measurements were performed on a single homogeneous panel, in order to check the reliability of the whole procedure and the repeatability of the measurements. Agood correspondence was found between theoretically calculated values and measured values of the sound reduction index above the critical frequency. A second set of measurements was carried out on model double walls comprising two leaves, connected to each other only by a border frame running along the whole wall perimeter. It was found that the effect of the border frame is a reduction of the performance of the double wall, to under that of a single plate with the same total surface mass. A third set of measurements was carried out inserting vertical studs to connect the two leaves. It was found that the presence of the studs causes a general decrease of the sound reduction index values and a decomposition of the critical frequency. Afourth set of measurements was carried out on the same double wall using border frames made of different materials. The experimental results show that damped materials (wood, rubber) give a better performance than rigid materials (acrylic, aluminium)
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
Advanced Process Control Applications to Water Resources Systems: Two Industrial Case Studies
No full textThis paper presents two industrial case studies where Advanced Process Control techniques have been applied. The first case study is represented by a hydroelectric plant located in Italy. In this plant, a model predictive controller has been designed and installed, in order to optimally satisfy the production plan. The predictive control approach has been motivated by the availability of forecasts on water requests by the hydroelectric plant and by the goodness of fit performances of the obtained linear process model. The second case study is represented by a pumping station located in an Italian Water Distribution Network. Advanced control logics have been designed in order to optimally and automatically manage the scheduling of the involved pumps. The developed Advanced Process Control systems have been successfully installed on the real plants, obtaining energy efficiency and process control improvement
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
Cani guida per non vedenti: addestramento e livelli di cortisolo
No full textThe aim of this study was to determine cortisol levels in plasma and hair of guide dogs during fosterage and training. Eighty-five dogs (32 M and 53 F) were used. Animals up to one year old were looked after by foster owners who dealed with their “socializing”; then, dogs were specifically trained for about six months for their future task. Dogs underwent monthly blood and hair sampling of that were used to determine cortisol levels by RIA. Significantly Higher levels in hair cortisol (P<0.01) were observed in dogs undergoing training as compared to the other group whereas fostered dogs showed higher levels of cortisol (P<0.01) in plasma. During the fosterage period, plasma levels of cortisol were higher in males (P<0.01) than in females, whereas hair levels were similar. During the training period, no differences between sexes were detected
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