1,720,999 research outputs found
A Cost-effective Indoor Vibrotactile Navigation System for the Blind
No full textThis paper describes the development of an indoor vibrotactile navigation system for the visually impaired people. We aimed at realizing a wearable, low-cost, and effective system able to help blind users in unknown indoor environments that they might visit occasionally, such as hospitals, airports, museums, etc.
The designed system implements a Bluetooth (BT) localization service, and provides wayfinding cues to the user by means of a wearable device equipped with five motors. The last part of our work describes early results obtained by the use of electroencephalographic (EEG) analysis to evaluate the vibrotactile feedback
EEG correlates of postural audio-biofeedback
No full textThe control of postural sway depends on the dynamic integration of multi-sensory information in the central nervous system. Augmentation of sensory information, such as during auditory biofeedback (ABF) of the trunk acceleration, has been shown to improve postural control. By means of quantitative electroencephalography (EEG), we examined the basic processes in the brain that are involved in the perception and cognition of auditory signals used for ABF. ABF and Fake ABF (FAKE) auditory stimulations were delivered to 10 healthy naive participants during quiet standing postural tasks, with eyes-open and closed. Trunk acceleration and 19-channels EEG were recorded at the same time. Advanced, state-of-the-art EEG analysis and modeling methods were employed to assess the possibly differential, functional activation, and localization of EEG spectral features (power in alfa, beta, and gamma bands) between the FAKE and the ABF conditions, for both the eyes-open and the eyes-closed tasks. Participants gained advantage by ABF in reducing their postural sway, as measured by a reduction of the root mean square of trunk acceleration during the ABF compared to the FAKE condition. Population-wise localization analysis performed on the comparison FAKE – ABF revealed:
(i) a significant decrease of alfa power in the right inferior parietal cortex for the eyes-open task; (ii) a significant increase of gamma power in left temporo-parietal areas for the eyes-closed task; (iii) a significant increase of gamma power in the left temporo-occipital areas in the eyes-open task. EEG outcomes supported the idea that ABF for postural control heavily modulates (increases) the cortical activation in healthy participants. The sites showing the higher ABF-related modulation are among the known cortical areas associated with multi-sensory, perceptual integration, and sensori-motor integration, showing a differential activation between the eyes-open and eyes-closed conditions
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Effect of refrigerated storage on muscle lipid quality of sea bass (Dicentrarchus labrax) fed on diets containing different levels of vitamin E
No full textThe effect of refrigeration at 1 degrees C on total lipid, phospholipid and fatty acid content of muscle was examined in 4 groups of sea bass (Dicentrarchus labrax) fed diets rich in fish oil and supplemented with increasing levels of vitamin E as antioxidant (139, 254, 495, and 942 ppm, respectively). After 1, 3, 6, 9 and 12 days refrigeration, muscle from the 4 sea bass groups contained increasing concentrations of vitamin E ton average 9.4, 13.1, 19.8 and 28.8 ppm) related to diet levels. However lipid parameters were unaffected until the end of the trial. The results indicate that the experimental conditions preserve lipid quality in sea bass muscle at least over the time range examined, irrespective of dietary formula. (C) 1999 Elsevier Science Ltd. All rights reserved
The influence of different levels of dietary vitamin E on sea bass (Dicentrarchus labrax) flesh quality
No full textSea bass Dicentrarchus labrax fillet quality was investigated after feeding with four diets (A, B, C or D) containing different levels of dietary vitamin E (139 mg kg-1, 254 mg kg-1, 493 mg kg-1 and 942 mg kg-1, respectively). Six-hundred and eighty fish (mean initial weight 208 g) were equally divided into four 20 m3 tanks and fed for 87 days. Filtered seawater with a temperature ranging from 18.2 to 26.3 °C was supplied continuously. At the end of the experiment, fish were stored at 1 °C for 12 days. At one, three, six, nine and 12 days, 20 fish per group were processed for proximate composition, vitamin E and induced thiobarbituric acid reactive substances (TBARs) analyses. No significant differences in proximate composition were registered between groups. The flesh lipid content ranged from 88.0 g kg-1 (group B) to 96.8 g kg-1 (group A). Vitamin E fillet content was significantly different between groups, reaching levels of 98.0, 150.7, 225.2 and 302.0 μg g-1 lipids for group A, B, C and D, respectively. Induced TBARs values were statistically different only for group A compared with the other groups. No significant variations were registered in relation to preservation time. Because of the positive influence of vitamin E on seafood quality and the correlation between its dietary level and flesh deposition, the α-tocopherol content of the diet should be well above fish minimum requirements
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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