1,720,980 research outputs found
Comparison of High-Resolution Pressure Peaks in Closed and Open-Section Wind Tunnels
No full textWind tunnel testing represents an established technique for the assessment of wind-induced pressure on cladding systems. Nonetheless, some physical events, such as the strong negative peaks of pressure that occur on a building’s lateral facades, are not fully understood. These events can be catastrophic for cladding systems, which motivates their further investigation. The objective of the present work is to study the nature of extreme suction events, by comparing high-resolution pressure tap measurements on a high-rise building collected at two different facilities: the closed-circuit wind tunnel of Politecnico di Milano, and the open-circuit Wall of Wind facility at Florida International University. We first compare the statistics of the two atmospheric boundary layers, and subsequently present results for the mean and root mean square pressure distributions and negative peak pressure events. The experiments provide consistent results, and they both exhibit two types of negative peak pressure events: one is characterized by an extremely short duration and spatial extension, while the other impacts a larger portion of the facade
A comparative analysis of construction costs of onshore and shallow- and deep-water offshore wind farms
No full textRecent years have seen renewed effort in the technological development of wind energy industry, where alongside onshore and shallow water offshore turbines, deep water offshore turbines have made their appearance, which represent the next frontier. One of the main aspects while developing a wind energy project is the overall cost and its breakdown between the main components. A comparative analysis of the costs associated with the different solution, the assessment of the key parameters of the wind economy, is therefore crucial when evaluating the possible investments. The aim of this work is to compare typical costs of onshore, shallow- and deep-water offshore wind farms, through an analysis of the aspects that characterize the wind economy, such as the cost of capital and operation and maintenance, and of their subheadings
Probabilistic Assessment of the peak response of horizontal axis wind turbines to wind and seismic actions
No full textThis study presents some results on the peak response assessment of a 5-MW, land-based Horizontal Axis
Wind Turbines (HAWTs) support structure, under the combined effects of wind and seismic loads. Using a
decoupled approach, simulations of the wind and seismic loads effects are performed separately applying a
specific model to define the aerodynamic damping and then joined. Then, the probabilistic assessment of
the multi-hazard peak response parameters was developed from Monte Carlo simulations of the tower
structure subjected to different wind and seismic loads scenarios
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
The effect of lift-up buildings on wind-induced forces and ventilation in simple urban geometries
No full textVariations 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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