1,721,033 research outputs found
Full-Wave Modeling of Via Holes and Equivalent Circuit Extraction for Signal Integrity Analysis
No full textEfficient modeling of discontinuities and dispersive media in printed transmission lines
No full textThe finite-difference time-domain method is applied
to the analysis of transmission lines on printed circuit boards. The
lossy, dispersive behavior of the dielectric substrate is accurately
accounted for by means of several algorithms whose accuracy is
discussed and compared. Numerical results are validated by comparisons
with measurements and an equivalent circuit of slot in the
ground plane is proposed
Differential Signalling in PCBs: Modeling and Validation of Dielectric Losses and Effects of Discontinuities
No full textThis paper focuses on differential signal transmission
above ground planes with gaps, taking into account the dielectric
and conductive losses of the substrate. An equivalent lumped circuit is proposed and its suitability is investigated by comparing
the obtained numerical results With the measured data. Furthermore the differential to common mode conversion of the waves, while crossing the gap, is theoretically analyzed and experimentally verified
Extraction of SPICE-type equivalent circuits of signal via transitions using the PEEC method
No full textDigital devices and discontinuities are typically analyzed by inserting their equivalent circuits into SPICE-type simulators. The partial element equivalent circuit (PEEC) method has been proven to be very useful for electromagnetic modeling. It can be used in both the time and the frequency domain. We employ the PEEC technique as an efficient full-wave modeling tool to derive SPICE-type equivalent circuits of signal via transition structures. A nodal analysis technique is utilized in conjunction with an optimization algorithm to extract the equivalent circuits, whose component values are the parameters optimized. The good agreement between different approaches demonstrates that the proposed approach can be a powerful tool for deriving the equivalent circuits of signal via transitions
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
Derivation of homogeneous permittivity of composite materials with aligned cylindrical inclusions for causal electromagnetic simulations
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