1,721,050 research outputs found
A robotic cutting tool for contaminated structure maintenance and decommissioning
No full textAbstract With the global dependency on fossil fuels being undermined by growing prices and environmental concerns, nuclear power is returning as a solution for energy demands, however the increased cost of maintaining and updating ageing plants could render them nuclear alternative counter-economic. The development of tools specifically targeted at the maintenance field is vital to ensure the longevity and safety of existing power plants. This paper proposes a robotic tool capable of remotely cutting composite material structures. With design and engineering focused on the safety of the operator and automation, the proposed machine presents sufficient flexibility to be utilised in both maintenance and decommissioning of structures with low to medium levels of radioactive contamination
Fattori di rischio macroeconomici e rendimenti delle strategie di portafoglio: ipotesi teoriche ed evidenza empirica
Full text linkFrom Fama-French (1993) and Carhart (1997) studies, which identify size, value, and momentum factors in addition to market risk as significant drivers of stock returns, the micro-finance research addressed the measurement of macroeconomic factors’ impacts on returns of portfolio strategies based on these multi-factor models. These analyses could be crucial in explaining the low or negative correlation often found in literature between the returns of such strategies (Cooper-Priestley 2009; Avramov et al. 2012; Asness et al. 2013; Wisniewski-Jackson 2020; Dahlquist-Hasseltoft 2020).
The contribution of this paper is twofold: i) to explain the theoretical foundation of expected impacts of the main macroeconomic factors on the returns of value and momentum strategies regarding equity and bond asset classes; ii) to verify whether these relationships are supported (in terms of sign and statistical significance) by the most recent empirical literature. The analysis shows that: i) univocal hypotheses on the expected links cannot be formulated; the causes of persistent returns of the two strategies, in fact, can be explained by adopting different theoretical perspectives, behavioural vs risk-premium models, which assume different linkages with macroeconomic factors; ii) the empirical findings are mixed; they could be also explained by differences, among studies, in country
samples (Continental Europe, Emerging Markets, UK, Developed Asia, and
USA), time periods, and testing methodology used. Nonetheless, the provided literature review is useful in delineating a comprehensive framework of the expected and empirically observed links
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
Two-spinor form of first-order gravity coupled to Dirac fields
No full textA two-spinor formalism for the Einstein Lagrangian is developed. The gravitational field is regarded as a composite object derived from soldering forms. Our formalism is geometrically and globally well-defined and may be used in virtually any 4m-dimensional manifold with arbitrary signature as well as without any stringent topological requirement on space-time, such as parallelizability. Interactions and feedbacks between gravity and spinor fields are considered. As is well known, the Hilbert–Einstein Lagrangian is second order also when expressed in terms of soldering forms. A covariant splitting is then analysed leading to a first-order Lagrangian which is recognized to play a fundamental role in the theory of conserved quantities. The splitting and thence the first-order Lagrangian depend on a reference spin connection which is physically interpreted as setting the zero level for conserved quantities. A complete and detailed treatment of conserved quantities is then presented
Andrologia e sessualità: un'indagine sul territorio
No full textricerca sui centri italiani di andrologia e sulle problematiche più frequenti degli utent
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