1,721,000 research outputs found
Sviluppo di un sistema Brain-Computer Interface per il controllo ambientale
Full text linkUna Brain-Computer Interface (BCI) è un sistema per la comunicazione non muscolare tra uomo e macchina, basata sull’acquisizione (non-invasiva) e l’elaborazione in tempo reale dell’attività cerebrale.
Le BCI sono prevalentemente basate sul segnale elettroencefalografico (EEG), nel quale alcune caratteristiche (e.g. componenti in frequenza, risposte a stimoli sensoriali) correlano con processi cognitivi dell’utente che ne specificano l’intenzione, anche in assenza di un comportamento motorio.
Esse costituiscono in prospettiva un sistema di ausilio alla comunicazione e controllo per persone con gravi disabilità motorie o per persone che solo temporaneamente si trovano in situazione o ambienti in cui la loro mobilità risulta ridotta, si pensi ad esempio agli astronauti.
Dagli anni ‘90 sono oggetto d’indagine scientifica (più di 500 lavori pubblicati solo nel 2009), ma mancano ancora studi sull’utilizzabilità di sistemi basati sul BCI per le attività della vita quotidiana.
Il lavoro svolto è stato finalizzato alla traslazione delle conoscenze disponibili in campo BCI, al fine di favorirne l’utilizzo al di fuori del laboratorio di ricerca
Si è partiti da un survey delle conoscenze disponibili in letteratura, con particolare attenzione ai meccanismi neurologici per la comunicazione non-muscolare. E si è poi passati allo sviluppo e validazione di interfacce utente non visive, volte a favorire la portabilità e l’utilizzo in concorrenza con azioni che interferirebbero con l’attenzione visiva. Inoltre si è sviluppato e validato un sistema per il controllo domotico utilizzabile tramite un BCI. Infine si è passati alla progettazione e realizzazione di dispositivi embedded per l’implementazione di un BCI.A Brain-computer Interface (BCI) is a system that allow non muscular communication between man and machine, based on the acquisition (not-invasive) and the real time elaboration of the cerebral activity. The BCIs are predominantly based on the electroencephalography signal (EEG), in which some characteristics (e.g. frequency components, response to sensory stimuli) correlate with the user’s trials cognitive specifying his intentions, also in absence of a motor behavior. BCI systems constitute in perspective a aid to the communication and control for people with serious motor disability or for people that temporarily are in situations or environment that reduce which their mobility, for example the astronauts.
From 90s BCI system are object of scientific investigation (more than 500 jobs were published only in the 2009), but studies on the usability of BCI system for daily life activities still miss.
The developed job is finalized to the translation of the available knowledge in BCI field, with the purpose of bring it out from the research laboratory. This work starts from a survey of the available knowledge in literature, with particular attention to the neurological mechanisms for the not-muscular communication. Then we as passed to the development and validation of non visual user interface, directed to favor the portability and the use in competition with actions that would interfere with the visual attention. Furthermore we developed and validated a system for the domotic control usable through a BCI. Finally we passed to the planning and realization of embedded devices for the implementation of a BCI
Attending to tactile, visual or bimodal targets: effects on the P3 and the relevance for brain machine interfaces
No full textThe P3 is a peak in EEG occurring after the presentation of a target. Research has focused on visual and auditory P3s. However, for controlling brain machine interfaces, tactile P3s are more suitable since tactile stimuli are not noticed by others and keep the user's eyes and ears free. We investigated P3s in response to tactile and visual stimuli unimodally, and bimodally. The tactile stimulus was a burst of vibration delivered by one of eight tactors around the waist. The analogous visual stimulus was a flashed circle in a schematic representation of the tactor layout. Participants attended to the vibrations and/or flashes of the target presented amongst non-targets. Tactile targets evoke stronger P3s than visual targets on frontal and central electrodes; the opposite happens on the occipital channel. Visuo-tactile stimuli only modestly strengthened the P3. We conclude that tactile stimuli applied to the waist are suitable to elicit P3s and have great potential for use in BMIs. In a follow-up study, we demonstrate this by building an example BMI
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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