1,721,292 research outputs found
Optimal Interception of Evasive Missile Warheads: Numerical Solution of the Differential Game
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Probability of precipitation using SEVIRI-like data and artificial neural networks.
No full textMETEOSAT-8 provides new means to address the challenge of using geostationary satellite data to estimate precipitation: the SEVIRI sensor has higher spatial and temporal resolution and a higher number of spectral channels than the old METEOSAT sensor. This work aims to assess quantitatively the potential
improvement due to the new channels. Appropriate visible (VIS) and infrared (IR) channels on the MODIS instrument have been used to simulate SEVIRI channels. Artificial Neural Network (ANN) techniques have been adopted to establish an indirect procedure to estimate Probability of Precipitation (PoP). The PoP ANN estimator is used to classify cloudy pixels into rain and no rain classes (with a threshold value of 1/32 mm h-1) and its performance has been assessed in terms of the Equitable Threat Score (ETS). The analysis involves winter season and morning/early night hours. The results obtained were compared with the most nearly corresponding METEOSAT-based scheme available in the Nimrod nowcasting system of the Met Office (UK). The evident impact of new channels on the performance shows that a new SEVIRIbased scheme could provide better estimation of precipitation. An optimum set of channels and features (Local Variability and Textural) useful for an operational operative PoP estimator has been selected and proposed in both day and night-time cases. In daytime, the 1.6μm channel combined with a visible
channel showed remarkable skill at distinguishing raining from non-raining pixels
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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