1,720,969 research outputs found
Electrocardiogram features detection using stationary wavelet transform
Get PDFThe main objective of this paper is to provide a novel stationary wavelet transform (SWT) based method for electrocardiogram (ECG) feature detection. The proposed technique uses the detail coefficients of the ECG signal decomposition by SWT and the selection of the appropriate coefficient to detect a specific wave of the signal. Indeed, the temporal and frequency analysis of these coefficients allowed us to choose detail coefficient of level 2 (Cd2) to detect the R peaks. In contrast, the coefficient of level 3 (Cd3) is determined to extract the Q, S, P, and T waves from the ECG. The proposed method was tested on recordings from the apnea and Massachusetts Institute of Technology–Beth Israel hospital (MIT-BIH) databases. The performances obtained are excellent. Indeed, the technique presents a sensitivity of 99.83%, a predictivity of 99.72%, and an error rate of 0.44%. A further important advantage of the method is its ability to detect different waves even in the presence of baseline wander (BLW) of the ECG signal. This property makes it possible to bypass the filtering operation of BLW
ECG Generator for Educational Biomedical Engineering Laboratory
Get PDFThe aim of this work is to design and implement an ECG generator for didactic biomedical engineering laboratory. The proposed generator provides analog ECG signals using synthesized or experimental records. The technique used in this work consists to generate the desired ECG waveforms through the PWM outputs of an Arduino board and low-pass filter. To provide many educational functions in both analog instrumentation and digital processing, the generator supplies output voltages in asymmetric or differential mode. To allow the user to setup the ECG signal to be generated, a LabVIEW application has been implemented. Experimentations on proposed generator and results were accomplished using the NI USB 6009 acquisition module and NI MAX software
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Design and SystemC-AMS Modeling of a Parallel Direct Digital Synthesizer
Get PDFThis paper presents a new parallel direct digital frequency synthesis (PDDS) circuit providing simultaneous multichannel. The proposed circuit has several applications in instrumentation, identification and data communications. After analysis of a set of design architectures and their limitations, we opted for a rapid and optimized architecture using Wave Arithmetic Unit (WAU) to operate in a largest frequency range. The effectiveness of our proposed circuit is demonstrated by a high-level design of digital blocks in SystemC and analog blocks in SytsemC-AMS language. Finally, the analysis of result responses of all modules confirms the correct PDDS performances for an open microelectronic integration technology
Solution analytique et généralisation d'un contraste à référence
Get PDF- Cet article traite du problème de la séparation aveugle de sources par la considération d'un système à référence. À partir d'un contraste à référence, on construit une famille de contrastes puis on développe une solution analytique. Les résultats de simulation présentent une comparaison de notre proposition avec le contraste de base et en tenant compte de plusieurs valeurs du paramètre de généralisation
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