1,720,957 research outputs found
Numerical simulations of full-scale enclosure fires in a multilevel library
No full textIn accordance with European policy, Italian regulations concerning building fire safety have been reformulated from prescriptive into performance-based rules. In this context field modeling based on Computational Fluid Dynamics methodology can potentially be applied to fire safety design in order to assess the performance of different designs and safety measures over a wide range of scenarios, so as to minimize the potential danger to life and property. In this work, a CFD code has been used to estimate the consequences of a fire occurring in a multilevel library. The evolution of gas temperatures, velocity field, radiative heat flux, gas and smoke concentrations has been predicted after the fire start. Simulation results have been evaluated with reference to tenability conditions along the evacuation paths in the building. Results have been also used to estimate the exposure to heat of the library ceilings and walls. © 2010 Taylor & Francis Group, London
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
Sensitivity analysis of a computer code for modelling confined fires
No full textFull scale experiments of tunnel fires are expensive and difficult to be carried out while tunnel fires simulation by computer modelling is cheaper and faster. Therefore, such a tool can replace the experiments if simulation results are recognized to be reliable and reflecting the reality. A computational fluid dynamics (CFD) code AIR was employed for the description of the transient behaviour of confined fires. The code solves the balance equations for the conservation of mass, momentum, energy and gas species within the physical domain of interest and yields local predictions of temperature, velocity, smoke, species concentration, etc, as a function of time. Firstly a sensitivity analysis of the computer code with respect to its parameters was performed, then experimental data from literature were employed to test the computer code performances. Simulations were obtained for a small scale steady-state tunnel fire and for an unsteady-state tunnel fire. AIR's performances in simulating tunnel fires were fair. Results depend on code parameters (grid fineness, number of iterations and step time interval) and on initial and boundary conditions such as temperatures, ventilation, heat release rate and radiant and convective heat transfer at the walls. The main AIR's limit is that it cannot manage radiative heat exchange with the walls and time variable boundary conditions as those encountered in transient tunnel fires
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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