1,721,149 research outputs found
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
31P Nuclear Magnetic resonance study of growth and dimorphic transition in Candida albicans.
No full textA 31P NMR study of the fungal pathogen Candida albicans was carried out. Yeast-form cells at
different phases of growth, as well as germ tubes and hyphae were examined. In all cases, the
NMR spectra showed well separated resonance peaks arising from phosphorus-containing
metabolites, the most prominent being attributable to inorganic phosphate (P,) polyphosphates,
sugar phosphates and mononucleotides, NAD, ADP and ATP. Relevant signals were also
detected in the phosphodiester region. The intensity of most signals, as measured relative to that
of PI, was clearly modulated both at the different phases of growth and during yeast-to-mycelium
conversion, suggesting significant changes in the intracellular concentration of the corresponding
metabolites. In particular, the intensity of the polyphosphate signal was high in
exponentially growing, yeast-form cells, then progressively declined in the stationary phase, was
very low in germ tubes and, finally, undetectable in hyphae.
NMR spectral analysis of the PI region showed that from early-stationary phase, P, was
present in two different cellular compartments, probably corresponding to the cytoplasm and
the vacuole. From the chemical shift of Pi, the pH values of these two compartments could be
evaluated. The cytoplasmic pH was generally slightly lower than neutrality (6.74-8), whereas
the vacuolar pH was always markedly more acidic
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
Dispersed generation units providing system ancillary services in distribution networks by a centralised control
No full textNew ESPRIT-based method for an efficient assessment of waveform distortions in power systems
No full textAn Optimal Control of Distributed Energy Resources to Improve the Power Quality and to Reduce Energy Costs of a Hybrid AC-DC Microgrid
No full textExponential weighted method and a compromise programming method for multi-objective operation of plug-in vehicle aggregators in microgrids
No full textDistribution networks are undergoing radical changes due to the high level of penetration of dispersed
generation and storage systems. This trend is strongly modifying the structure as well as the management
of distribution networks, which are progressively approaching the new concept of microgrids
(MGs). Also, the level of penetration of storage systems for plug-in electric vehicles (PEVs) is increasing
significantly due to the significant potential that PEVs have for reducing both emission levels and transportation
costs. The inclusion of these vehicles in MGs leads to a series of challenges in grid operation,
especially ensuring the provision of services that can improve the operation of distribution networks.
This paper deals with MGs, including renewable generation plants and aggregators of PEV fleets
connected to the grid through power electronic devices. A multi-objective optimization model is
presented for obtaining optimal, coordinated operation of MGs. A multi-objective model was solved using
two different methods, i.e., the exponential weighted criterion method and a compromise programming
method. Both of these methods appeared to be particularly suitable when computational time is an
important issue, as it is in the case of optimal control. The effectiveness of the multi-objective approach
was demonstrated with numerical applications to a low-voltage microgrid; other multi-objective
model-solving algorithms also were assessed in order to compare their programming complexity and
the computational efforts required
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