1,721,059 research outputs found
Minimal Forcemyography Human-Machine Interface for Hand Gesture Recognition
No full textThis study proposes a very simple Human-Machine Interface (HMI) to recognize six basic hand gestures. The device is equipped with only two forcemyography (FMG) sensors applied to specific forearm muscles and it is a scaled-down version of a previous one used for gesture recognition and control of exoskeletons and prostheses. Data collected from five healthy subjects were considered. A double-threshold segmentation technique of the two FMG signals allowed the extraction of features (i.e., mean, standard deviation, root mean square, area, slope) to recognize the hand gestures. Features were recalculated every 100 ms to provide real-time performance. Classification performance was evaluated using both Linear Discriminant Analysis (LDA) and a Linear-Support Vector Machine (L-SVM) classifier and applying 10-fold cross-validation. The mean accuracy across all subjects resulted in 93.07% and 96.14% using LDA and L-SVM, respectively. In summary, this research represents a further step forward in the field of FMG-based HMIs. The reduction of FMG sensors and optimization of data processing techniques, including segmentation and feature extraction, provide a more effective and easier-to-use HMI that can be employed in a variety of applications ranging from computer applications, games, prosthesis and exoskeleton control, etc
Use of the PAH fingerprints for identifying pollution sources
No full textMolecular signatures are investigated since long time for source assessment; characteristic behaviours are sought both in emission and aerosol composition. In this study, particulates released by stationary and vehicle sources were characterised for PAH contents by using similar top-to-bottom procedures. Group fingerprints and concentration ratios between pairs of compounds were investigated. The approach based on diagnostic ratios was applied to the study-cases of cities lying in Northern, Central and Southern Italy, and of localities in the Rome province, exposed to emission sources of different strength and nature. The results were compared with those observed in the Mediterranean Sea Region. In general, vehicles were confirmed as the principal source of PAHs, while minor and season dependent contributions could be associated to wood burning and soil resuspension. Original molecular signatures identified felt promising in the perspective of the PAH source reconciliation. (C) 2014 Elsevier B.V. All rights reserved
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
Naps, cognition and performance
No full textDaytime napping is a frequent habit of many individuals, whether healthy or not, and may occur in a wide variety of contexts. There are several reasons for napping in the human adult, including prophylactic strategies or recuperative need, respectively before or after sleep loss, or even pure appetitive drive. Thus, it is of great theoretical and clinical interest to assess the impact of naps on individuals’ performance, especially on cognitive functioning. As the outgrowth of a symposium held by the authors at the 5th Congress of the World Federation of Sleep Research and Sleep Medicine Societies in Cairns, Australia, September 2007, this review will specifically explore: a) the newly developed experimental daytime split-sleep schedules and their effects on recovery, compared with those deriving from a single consolidated sleep episode of equal duration; b) whether naps may be beneficial to wakefulness performance in the working context, through accurate review of ‘‘on field’’ studies; c) the impact of naps on cognition, in light of the very recent advances in the study of naps and memory processes; d) the main features of napping behavior in older individuals and its impact on their health and general functioning, since it is widely recognized that napping may change as a result of the aging process
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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