1,720,972 research outputs found
Computation of information rates by means of discrete states density recursion
No full textStarting from the existing works on the computation of information rates of channels with memory, we present a modification of these methods that can be used for continuous-state space models. The principle used for developing this alternative method is based on the partitioning of the continuous-state space into sub-sets, each one representing a state of a trellis, and the association between the states and the probability density functions built and updated on such sub-sets. The paper discusses the cases in which the method provides a computational advantage and it presents numerical results regarding the relevant example of the Wiener phase noise model
Improved torsional exciter for non-destructive tests of structural members
No full textBritish extension of the Italian Patent N. 1216934, 198
Overview about E-Mobility Conducted Immunity Tests on ESA Communication Lines
Full text linkDue to the complexity of the Automotive Electromagnetic Compatibility legislation in force, this article aims to describe a simplified overview of several technical standards relating to conducted immunity tests on electronic sub-assemblies, where communication lines are involved. The discussed automotive standards reported in this article are: ISO 11452-1 and ISO 11452-4 for continuous narrowband electromagnetic fields immunity test, bulk current injection and tubular wave coupler, IEC 61000-4-5 for immunity against surge events, IEC 61000-4-4 for electrical fast transient/burst events immunity, ISO 10605 for electrostatic discharge events immunity, ISO 7637-2 and ISO 7637-3 for transient disturbances events immunity. For each cited standard, disturbance bandwidth evaluation was performed. Practical examples are reported, with analysis and discussion of some of the adoptable disturbance countermeasures applicable on controlled area network communication lines, and possible design advantages and disadvantages with different types of filtering and suppression circuit solutions
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
Performance Evaluation of LoS MIMO Microwave Radio Systems Over Frequency Selective Multipath Fading Channels
No full textAlthough spectrally efficient microwave LoS-MIMO (Line of Sight-Multiple Input Multiple Output) systems seem to be practically attractive mainly at higher frequency bands (above 15 GHz), also at lower frequency bands, where frequency selective multipath fading is the dominant impairment for the outage time, they could play a significant role. Under this perspective, the paper analyzes performance of LoS-MIMO systems affected by frequency selective fading, taking into account the necessary equalization for satisfying the outage objectives. For the purpose of the analysis, we adopted a frequency selective 2×2 LoS-MIMO channel model extrapolated from the 2-ray model historically used in SISO (Single Input Single Output) systems and, exploiting the full statistical behaviour of the propagation channel model, we described a methodology for the evaluation of frequency selective LoS-MIMO outage performance. Then the proposed methodology is used to investigate the effectiveness of equalization in the intersymbol and mutual interference reduction of two equalizer structures, linear MMSE and MMSE Partial Response, using as a practical reference the target outage probability predicted on the same link for a SISO system. Finally, it is discussed the opportunity of using the Condition Number of the LoS-MIMO channel matrix transfer function as an exhaustive indicator of the channel quality
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
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