1,721,005 research outputs found
Suppression of late-time instabilities in 3D-FDTD analyses by combining digital filtering techniques and efficient boundary conditions
No full textA new computational procedure is developed to suppress late-time instabilities in three-dimensional finite-difference time-domain analyses. The method combines low-pass filtering schemes with absorbing boundary conditions. The computational domain is truncated at only a few cells from the scattering object. Applications concern the analysis of long transients exciting frequencies up to a few megahert
Integral equation boundary conditions for the efficient FDTD analysis of low-frequency transient problems
No full textInnovative boundary conditions are proposed for the efficient truncation of FDTD grids in the analysis of low-frequency transient problems, in which the minimum excited wavelength is hundreds times greater than the space discretization step. The electromagnetic transient source is coupled inside the discretized FDTD domain by enforcing electric- and magnetic-field integral-equations on the grid borders. Critical aspects of the numerical implementation are discussed. Numerical applications demonstrate the validity of the proposed procedureInnovative boundary conditions are proposed for the efficient truncation of FDTD grids in the analysis of low-frequency transient problems, in which the minimum excited wavelength is hundreds times greater than the space discretization step. The electromagnetic transient source is coupled inside the discretized FDTD domain by enforcing electric- and magnetic-field integral-equations on the grid borders. Critical aspects of the numerical implementation are discussed. Numerical applications demonstrate the validity of the proposed procedur
Radiated susceptibility of wiring system aboard lightning struck aircraft. Part I: Sensitivity to the p.u.l. external parameters.
No full textMODELING OF MAGNETIC FIELD COUPLING WITH CABLE BUNDLE HARNESSES
No full textA field-to-line coupling model is developed for cable bundle harnesses in terms of the scattering currents and total line voltages. The equivalent distributed sources representing the effects of electromagnetic coupling are expressed as a function of the incident magnetic-field components. Such a formulation is particularly suitable to be used for the analysis of multiconductor transmission lines excited by a transient field, when data for the incident electric field are either inaccurate or not available. This model allows the accurate calculation of the induced voltages and currents on complex cable bundles. The effects on the induced voltages and currents due to ground losses and to the presence of the dielectric sheath in shielded and unshielded cables is discussed, considering bundles excited by either slow or fast transient fields. Numerical applications demonstrate the validity of the proposed procedure
On the use of fitting models for the time-domain analysis of problems with frequency-dependent parameters
No full text
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
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