1,721,221 research outputs found
The short FFT database and the peak map for the hierarchical search of periodic sources
No full textIn the hierarchical search for periodic sources the construction of the short FFT database (SFDB) plays a key role for the next steps of the search, in terms of easy and fast access to the needed information and of data quality. The last information is crucial when combining data over long time periods, given the presence of non-stationarities in the noise. We will outline here the procedure we use to construct the SFDB and in particular the peak map, which is the first step of the hierarchical procedure, describing the tools we use to remove disturbances, which would enhance the noise floor. We will also describe the data and information we evaluate and store to characterize each FFT Particular emphasis is given to the procedure used to construct the estimator of the average noise spectral density, which is needed for good detection efficiency in the identification of peaks. We will give some examples, using non-stationary data of the resonant detector Nautilus and simulated signals added to the noise
Evaluation of sensitivity and computing power for the Virgo hierarchical search for periodic sources
No full textIn this paper we present the hierarchical search for periodic gravitational sources that we propose for the data analysis of the Virgo and Explorer and Nautilus resonant gravitational antennae. All the equations that can be used to 'tune' the algorithm are presented
Complication in massive allograft reconstructions for bone tumours.
No full textAims: Massive allografts have been widely employed to replace skeletal defects after bone tumour resection. They have major advantages but the major concern is the long term behaviour of the implant. The aim of the present study was to evaluate the incidence of complications in allograft reconstruction and to describe the new techniques to decrease their rate. Methods: The present series includes 68 patients with 70 massive allografts operated from 1996 to 2002. 35 were males and 35 females with an average age of 31 years (4–79). The massive allograft was used as osteoarticular reconstruction in 28 cases, composite in 28, intercalary in 10, knee arthrodesis reconstruction in 3 and scapular replacement in one case. In 7 cases a vascularized fibula was associated. The femur was involved in 23 cases, the humerus in 16 and the tibia in 17, the pelvis in 7, the radius in 3, the scapula in 2 and patella and a finger in 1 case. Results: Infection rate on 68 cases was 6% (4 cases). All infections healed after surgical revision. Two patients were lost at fu and 10 patients have less than 12 months of fu. The 58 patients left have an average fu of 34 months (12–71). Among these patients 45% had one or more complications treated surgically and 2/3 of the cases healed. Non union rate was 12% and fracture rate 5%. Conclusion: Allograft reconstruction showed a high rate of complications. Almost half of the patients (45%) presented one or more complications which required surgery in 40% of cases. Aggressive antibiotic perioperative regimen and adequate soft tissue coverage of the graft may reduce the risk of infections. Biologic augmentation with vascularized grafts, bone marrow and/or growth factors may reduce non union rate. Cement filling of the graft and composite implant (with prosthesis association) have been introduced in order to decrease the risk of diaphyseal and articular fractures
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
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