1,720,994 research outputs found
On the Use of Complex Excitation Sequences for Eddy Current Testing
No full textEddy Current Testing (ECT) is a Non Destructive technique widely used in many industrial
application fields in which it is very important to detect the presence of thin defects ( generally called cracks) in
conductive materials. Features of this technique are the cost-effective implementation and the kind of retrieved
measured data that make possible estimating geometrical characteristics of a crack as position, length, width and
depth. The analysis of these characteristics allows the user to accept or discard realized components then
improving the production chain. To accomplish for this task some aspects have to be taken into account during
the measurement process. They mainly concern with the realization of suitable measurement setup and post
processing stages. As far as the measurement setup is concerned, crucial aspects are the choice of measurement
and excitation devices. As for the former, in the past years the literature deeply explored many types of
measurement probes highlighting advantages and disadvantages of different solutions. The choice of optimized
excitation devices and strategies is now interesting recent studies about Non Destructive ECT (ND-ECT):
together with common aspects as the amplitude and the frequency of the exciting signal, recently the attention
has been paid to issues as the type of signal to be adopted. In particular it has been found as the use of complex
excitation signals, meant as signals different from the sinusoidal ones and with wide frequency content, might
raise eddy current responses trying to support the measurement, detection and characterization stages when
“difficult cases” are explored (i.e. very short or annealed cracks). In this paper the authors propose an
experimental comparison of different excitation signal designed to improve the quality of experimental data
when difficult cases are experienced (such as annealed and small cracks) and consequently to obtain a more
reliable extraction of defects geometrical features
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
An FPGA-based instrument for the estimation of R, L, and C parameters under nonsinusoidal conditions
No full textIt is well know that the most of today electric and electronic devices frequently work with non sinusoidal waveforms, then, all the passive R, L, and C component, sited in these circuits, are involved with non sinusoidal stimuli. Because of its intrinsic non-linearity, real resistors, inductors, capacitors and so on show behaviors very different from those expected in sinusoidal environment. Consequently, a problem of reliable assessment of these components in presence of non sinusoidal environments arises. This problem is even more critical in applications such as the creation of hybrid filters, control circuits based on patterns of sensing elements, circuits of digital protection in power systems, where the design and control of electrical and electronic circuits depend on the correct modeling of the R, L and C components. In previous researches authors proposed a suitable measurement method for the estimation of R, L and C parameters of passive components in non sinusoidal conditions. This paper deals with the realization of a FPGA-based measurement instrument able to continuously update the estimated values of the considered components. The instrument realization passes through an optimized implementation of the previous-proposed measurement method aimed in minimizing the hardware resources and the computational burden, and increase the measurement rate. After a preliminary tuning of the measurement method, carried out in simulation environment, the hardware and the software architectures of the realized measurement instruments together with the measurement strategy are described, and experimentally characterize
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
Electrical energy metering: Some challenges of the European Directive on Measuring Instruments (MID)
No full textThe introduction of static electric energy meter together with voltage and current distortions in the electric networks are revolutionizing the measurement of the electrical energy. Several questions and studies are proposed in the scientific literature concerning with metrological and reliability aspects of the actual electrical energy measurement. The European Directive on Measuring Instruments (MID) represents a different spin on setting the performance and safety requirements for those meters. The International Organization of Legal Metrology (OIML) has published the document D11 discussing recommendations for legislation to meet the MID. An OIML technical committee is drafting the recommendation (IR46) that would give regulatory bodies an easily-adoptable set of requirements and tests to meet the requirements of the MID. With the introduction of the MID directive, the actual discussion involves aspects as the metrological characterization of the meters. The paper proposes an analysis of the test settings imposed by the actual MID-harmonized standards, regarding the electric energy metering. The aim is to check the presence of degree of freedom in the test settings that could compromise both result reliability and the compliance/non-compliance of a given apparatus
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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