111,935 research outputs found
A wavelet methodology for EEG time-frequency analysis in a time discrimination task
No full textEEG signals recorded by surface electrodes placed on the scalp can be thought as nonstationary
stochastic processes in both time and space, especially in response to external stimuli.
Cognitive tasks, in particular, are reflected by changes in EEG dynamics concerning both rhythms
energy and connectivity across different brain regions. In the frequency-domain, EEG analysis is
complicated and time-frequency methodologies are needed. The Wavelet Transform, in particular,
represents a powerful tool for analysing, within a time-frequency embedding, the EEG. In this study
we applied a wavelet-based methodology to extract quantitative time-frequency parameters from EEG
signals recorded during a time discrimination task in 12 subjects. We used a continous wavelet
transform with a complex Morlet as mother function. In order to improve the time-frequency resolution
and to make it satisfactory, each of the four standard EEG rhythms (i.e. theta, alpha, beta, gamma) was
studied with Morlet wavelet parameters tuned ad hoc on the basis of both the width of the specific
frequency band and the particular type of activity under examination. The numerical values of the
estimated time-frequency indexes were then compared, evidencing statistically significant differences
in the brain response between experimental conditions
Efficacia di interventi diserbanti e della pacciamatura organica nel controllo delle infestanti del rosmarino
No full textRisposta di Kalankhoe Blossfeldiana Poelln., Osateospermum e Fuchsia ibridi a differenti trattamenti con regolatori di crescita
No full textElectrophysiological correlates of reference memory in a time discimination task: an ERPand ERD/ERS study
No full textStrike-slip contractional stepovers in the Southern Alps (northeastern Italy)
No full textStrike-slip pop-ups are seldom recognized because they are sites of rapid uplift and erosion. In addition, they can easily be confused with shortening structures of different age. In the Neogene central-eastern Southern Alps, the western termination of the ENE-trending Valsugana thrust is located at the interference with the suborthogonal Calisio Line, which is an inverted Permian normal fault. Just west of the Calisio Line the Mt. Cornetto di Folgaria (MCF) structural and topographic high is a large-scale pop-up localised at the restraining stepover between the sinistral Calisio and Schio-Vicenza strike-slip faults, which trend at high angle to the thrust belt. The MCF pop-up developed in post-Tortonian times, when the kinematics of these faults changed from dextral to sinistral. At a smaller scale, strike-slip restraining and releasing stepovers of pre-existing steep fault segments show that these inherited faults are kinematically linked and constitute an important mechanical anisotropy responsible for strain partitioning into strike-slip and dip-slip displacements. The analysis of the MCF pop-up and related minor structures suggests that in fold-and-thrust-belts affected by strike-slip faults at high angle to the belt axis, contractional structures related to strike-slip restraining bends and stepovers may be more common than what is usually thought
Comparison Between Experimental and Simulated Knock Statistics Using an Advanced Fuel Surrogate Model
No full textThe statistical tendency of a GDI spark-ignition engine to undergo knocking combustion as a consequence of spark timing variation is numerically investigated. In particular, attention is focused on the importance to match combustion-relevant and knock-relevant fuel properties to ensure consistency with the experimental evidence. An inhouse surrogate formulation methodology is used to emulate real gasoline properties, comparing fuel models of increasing complexity. Knock is investigated using a proprietary statistical knock model (GruMo Knock Model, GK-PDF). The model can infer a log-normal distribution of knock intensity within a RANS formalism, by means of transport equations for variances and turbulence-derived probability density functions (PDFs) for physical quantities. The calculated distributions are compared to measured statistical distributions. The proposed numerical/experimental comparison constitutes an advancement in synthetic chemistry integration into 3D-CFD combustion simulations
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Artificial neural network algorithm for online glucose prediction from continuous glucose monitoring.
No full textBackground and Aims: Continuous glucose monitoring (CGM) devices could be useful for real-time management of diabetes therapy. In particular, CGM information could be used in real time to predict future glucose levels in order to prevent hypo-/hyperglycemic events. This article proposes a new online method for predicting future glucose concentration levels from CGM data.
Methods: The predictor is implemented with an artificial neural network model (NNM). The inputs of the NNM are the values provided by the CGM sensor during the preceding 20 min, while the output is the prediction of glucose concentration at the chosen prediction horizon (PH) time. The method performance is assessed using datasets from two different CGM systems (nine subjects using the Medtronic [Northridge, CA] Guardian® and six subjects using the Abbott [Abbott Park, IL] Navigator®). Three different PHs are used: 15, 30, and 45 min. The NNM accuracy has been estimated by using the root mean square error (RMSE) and prediction delay.
Results: The RMSE is around 10, 18, and 27 mg/dL for 15, 30, and 45 min of PH, respectively. The prediction delay is around 4, 9, and 14 min for upward trends and 5, 15, and 26 min for downward trends, respectively. A comparison with a previously published technique, based on an autoregressive model (ARM), has been performed. The comparison shows that the proposed NNM is more accurate than the ARM, with no significant deterioration in the prediction delay
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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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