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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A usabilidade e as tecnologias emergentes no desenvolvimento de produtos de consumo: uma abordagem em ambientes virtuais e neurociência

Vasconcelos, Christianne Soares Falcão e 24 October 2014 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-06-14T12:40:33Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese - versao para impressao (2).pdf: 20650405 bytes, checksum: fadce5f7df96f0068f4ff26a711ed388 (MD5) / Made available in DSpace on 2016-06-14T12:40:33Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese - versao para impressao (2).pdf: 20650405 bytes, checksum: fadce5f7df96f0068f4ff26a711ed388 (MD5) Previous issue date: 2014-10-24 / CAPEs / A avaliação da usabilidade representa uma tarefa essencial no ciclo de desenvolvimento do produto ao buscar uma maior satisfação do usuário e, consequentemente, o sucesso do produto no mercado. Para tal, torna-se fundamental a colaboração e a comunicação eficiente entre os diversos membros da equipe. Neste âmbito, tecnologias são desenvolvidas no sentido de promover um design participativo em todas as fases do processo de design e tem provocado uma mudança de paradigmas. O objetivo desta tese consiste em investigar o potencial das principais tecnologias para a usabilidade de produtos, buscando soluções que tornem a avaliação mais eficiente e inclusiva. Uma revisão de literatura sobre usabilidade e métodos é realizada, contextualizando o tema da pesquisa. Em seguida, as tecnologias emergentes da prototipagem virtual, simulações em ambientes virtuais e a interface cérebro-computador, ou neurociência para o design, são identificadas e suas possíveis aplicações na avaliação da usabilidade apontadas. A aplicação das tecnologias emergentes e o relacionamento destas entre si é avaliada em dois estudos de caso. O primeiro estudo consiste em dois experimentos com profissionais e estudantes de Design. Um questionário foi aplicado para investigar a situação atual da aplicação das tecnologias prototipagem virtual e realidade virtual, como também realizou-se um estudo comparativo entre protótipos. No segundo estudo, um teste de usabilidade com usuários reais utilizando um sistema EEG wireless foi realizado para investigar as atividades cerebrais durante o uso de um produto de consumo. Como resultado, várias lições foram aprendidas, correspondendo a uma importante contribuição para pesquisas no campo do design de produtos. A tese é finalizada com as lições aprendidas e são apresentadas sugestões para futuras pesquisas. / The usability evaluation is an essential task in the product development process to seek a greater user satisfaction and, consequently, the product success in the marketplace. For this, it is necessary the collaboration and effective communication among stakeholders. In this context, technology is developed in order to promote a participatory design at all stages of the design process and has resulted in a paradigm shift. The aims of this thesis are to investigate the potential of key technologies for testing the usability of products, and exploring solutions that make usability evaluation more efficient and comprehensive. A comprehensive literature review on usability and testing methods is provided by contextualizing the research theme. Then the emergent technologies of virtual prototyping, virtual environment simulation and brain computer interfacing or neuroscience for design are identified and possible applications in usability evaluation are outlined. The emerging technologies, their applications and how they relate to each other are evaluated in two case studies. The first study consists of two experiments with professional settings and with design students. A questionnaire was applied to investigate the present situation of virtual prototyping and virtual reality technologies application, and also a comparative study between prototypes was conducted. In the second study, a usability test with real users using a wireless EEG system was performed to investigate the brain activity during the use of a consumer product. As results show, several lessons were learned, representing an important contribution to research in the field of product design. The thesis concludes with best practices (lessons learned) and suggestions for further research.
2

Využitelnost nervového ovládání počítače / Applicability of the device for neural computer control

Němec, Pavel January 2011 (has links)
The main goal of this paper is to test the applicability of the device for neural computer control on a group of ten volunteers. In the next part of the paper author focuses on Electroencephalography and the conversion of analog neural signals from brain to digital form. Next chapter describes currently on the market available devices, which allow customers direct computer controlling with the usage of bio signal from brain. The device selected for the purposes of this paper (Emotiv Epoc) is more described in detail. The last goal is an attempt to predict the future development of this technology. The paper demonstrates applicability of this device in its current form for everyday work with Microsoft Project and presents users who are able to learn to control a computer with this device in just 980 minutes of training.
3

Brain-computer interface games based on consumer-grade electroencephalography devices: systematic review and controlled experiments / Jogos de interface c?rebro-computador baseados em dispositivos comerciais de eletroencefalograma: revis?o sistem?tica e experimentos controlados

Mendes, Gabriel Alves Vasiljevic 31 July 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-02T22:27:19Z No. of bitstreams: 1 GabrielAlvesVasiljevicMendes_DISSERT.pdf: 3791566 bytes, checksum: e847396390a6b6ca2128eefd4423f561 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-06T23:26:09Z (GMT) No. of bitstreams: 1 GabrielAlvesVasiljevicMendes_DISSERT.pdf: 3791566 bytes, checksum: e847396390a6b6ca2128eefd4423f561 (MD5) / Made available in DSpace on 2017-10-06T23:26:09Z (GMT). No. of bitstreams: 1 GabrielAlvesVasiljevicMendes_DISSERT.pdf: 3791566 bytes, checksum: e847396390a6b6ca2128eefd4423f561 (MD5) Previous issue date: 2017-07-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Brain-computer interfaces (BCIs) are specialized systems that allow users to control a computer or a machine using their brain waves. BCI systems allow patients with severe physical impairments, such as those suffering from amyotrophic lateral sclerosis, cerebral palsy and locked-in syndrome, to communicate and regain physical movements with the help of specialized equipment. With the development of BCI technology in the second half of the 20th century and the advent of consumer-grade BCI devices in the late 2000s, brain-controlled systems started to find applications not only in the medical field, but in areas such as entertainment. One particular area that is gaining more evidence due to the arrival of consumer-grade devices is the field of computer games, which has become increasingly popular in BCI research as it allows for more user-friendly applications of BCI technology in both healthy and unhealthy users. However, numerous challenges are yet to be overcome in order to advance in this field, as the origins and mechanics of the brain waves and how they are affected by external stimuli are not yet fully understood. In this sense, a systematic literature review of BCI games based on consumer-grade technology was performed. Based on its results, two BCI games, one using attention and the other using meditation as control signals, were developed in order to investigate key aspects of player interaction: the influence of graphical elements on attention and control; the influence of auditory stimuli on meditation and work load; and the differences both in performance and multiplayer game experience, all in the context of neurofeedback-based BCI games.
4

An Evaluation of Gaze and EEG-Based Control of a Mobile Robot

Khan, Mubasher Hassan, Laique, Tayyab January 2011 (has links)
Context: Patients with diseases such as locked in syndrome or motor neuron are paralyzed and they need special care. To reduce the cost of their care, systems need to be designed where human involvement is minimal and affected people can perform their daily life activities independently. To assess the feasibility and robustness of combinations of input modalities, mobile robot (Spinosaurus) navigation is controlled by a combination of Eye gaze tracking and other input modalities. Objectives: Our aim is to control the robot using EEG brain signals and eye gaze tracking simultaneously. Different combinations of input modalities are used to control the robot and turret movement and then we find out which combination of control technique mapped to control command is most effective. Methods: The method includes developing the interface and control software. An experiment involving 15 participants was conducted to evaluate control of the mobile robot using a combination of eye tracker and other input modalities. Subjects were required to drive the mobile robot from a starting point to a goal along a pre-defined path. At the end of experiment, a sense of presence questionnaire was distributed among the participants to take their feedback. A qualitative pilot study was performed to find out how a low cost commercial EEG headset, the Emotiv EPOCTM, can be used for motion control of a mobile robot at the end. Results: Our study results showed that the Mouse/Keyboard combination was the most effective for controlling the robot motion and turret mounted camera respectively. In experimental evaluation, the Keyboard/Eye Tracker combination improved the performance by 9%. 86% of participants found that turret mounted camera was useful and provided great assistance in robot navigation. Our qualitative pilot study of the Emotiv EPOCTM demonstrated different ways to train the headset for different actions. Conclusions: In this study, we concluded that different combinations of control techniques could be used to control the devices e.g. a mobile robot or a powered wheelchair. Gaze-based control was found to be comparable with the use of a mouse and keyboard; EEG-based control was found to need a lot of training time and was difficult to train. Our pilot study suggested that using facial expressions to train the Emotiv EPOCTM was an efficient and effective way to train it.
5

Detection of Lateralized Readiness Potential using Emotiv EPOC / Detekce LRP pomocí Emotiv EPOC

Bártík, Radovan January 2013 (has links)
Emotiv EPOC is a low-cost consumer headset capable of acquiring a raw EEG signal. The thesis evaluates its usage for an acquisition of research event-related potentials. A controlled laboratory experiment was performed with an objective of isolating the Bereitschaftspotential (Readiness Potential) and other movement-related potentials and comparing the results with the results of the previous research. The possibility of measuring the potential with Emotiv EPOC was not confirmed, most probably due to procedural issues during the experiment, however, further analysis of the data suggests its presence. Other outcomes of the research include qualitative findings about the headset, mainly its hardware construction, and testing feedback of EEGLab, an open source toolbox for EEG processing and visualization.
6

Εφαρμογή ασύρματης ηλεκτροεγκεφαλογραφίας σε άτομα με δυσλεξία / Application of wireless EEG on adults with dyslexia

Κλεάνθους, Τίνα 10 June 2014 (has links)
Τα τελευταία χρόνια, το πρόβλημα της απόκτησης και χρήσης ενός συστήματος ηλεκτροεγκεφαλογραφίας λόγω του υψηλού κόστους του έχει υπερπηδηθεί με την κυκλοφορία πολλών εναλλακτικών συστημάτων λιγότερων δαπανηρών. Το πιο εξελιγμένο από αυτά του μικρού κόστους συστήματα είναι το Emotiv Epoc. Ένα επιπλέον πλεονέκτημα του Emotiv Epoc έναντι των συμβατικών συστημάτων ηλεκτροεγκεφαλογραφίας αποτελεί το γεγονός ότι είναι ασύρματο. Το γεγονός αυτό ανοίγει καινοτόμες οδούς στο πεδίο το νευροεπιστημών αφού δύναται η εκτέλεση πειραμάτων ευρέων εφαρμογών όπως π.χ. λήψη ηλεκτροεγκεφαλικών μετρήσεων εν κινήσει. Μια τέτοια εφαρμογή μπορεί επίσης να αποτελεί και η εκτέλεση πειραμάτων σε μικρά παιδιά στα οποία η καλωδίωση μπορεί να καταστεί πολύ δύσκολη. Με βάση λοιπόν τα παραπάνω, ένα τέτοιο σύστημα θα μπορούσε να χρησιμοποιηθεί με επιτυχία σε παιδία για έγκαιρη διάγνωση της δυσλεξίας η οποία κρίνεται επιβεβλημένη σε πολύ μικρές ηλικίες .Μειονέκτημα όμως ενός τέτοιου ασύρματου συστήματος θα μπορούσε να υποθέσει κανείς ότι είναι η αυξημένη παρουσία θορύβου. Ο θόρυβος αυτός θα μπορούσε να πηγάζει τόσο κατασκευαστικά ( αφού η πληροφορία καταγράφεται ασύρματα ) όσο και λόγω του γεγονότος ότι τέτοιου είδους πειράματα δεν λαμβάνουν χώρα σε μονωμένο ηλεκτρομαγνητικά περιβάλλον. Επιπρόσθετα, οι ηλεκτρονικοί υπολογιστές είναι απαραίτητοι προκειμένου να σχεδιαστεί και να εκτελεστεί ένα οποιοδήποτε πείραμα προκλητών δυναμικών και η αξιοπιστία τους ως ένα μεγάλο βαθμό εξαρτάται από αυτούς. Παρόλα αυτά, η πλειοψηφία των ηλεκτρονικών υπολογιστών λόγω του ότι η χρήση τους βρίσκει εφαρμογή σε μια πληθώρα εφαρμογών δεν καθίσταται δυνατό να παρέχει την χρονική ακρίβεια η οποία είναι απαραίτητη σε τέτοιου είδους πειράματα. Σκοπός της παρούσας διπλωματικής εργασίας είναι η διερεύνηση του κατά πόσο ένα τέτοιο σύστημα ασύρματης ηλεκτροεγκεφαλογραφίας όπως το Emotiv Epoc σε συνδυασμό με τους ηλεκτρονικούς υπολογιστές τους οποίους έχουμε στην διάθεση μας, μπορεί να χρησιμοποιηθεί σε πειράματα προκλητών δυναμικών σε άτομα με δυσλεξία για την ανάκτηση μετρήσεων μεγάλης ακρίβειας. / In recent years, the low-cost wireless EEG systems have become available, spurred by applications in the game industry. These systems offer a wider and more innovative range of options, for example EEG recordings while in motion and are easier to use so they are suitable for children and special populations. For example such systems can in principle be used for mass screening for early diagnosis of dyslexia, an application of tremendous importance for the individual and society. One of the most advanced such systems is the Emotiv Epoc. The wider and more innovative range of options that EEG systems like the Emotiv Epoc provide cannot however be applied to neuroscience experiments, before some technical limitations are overcome. One such drawback is the higher noise levels compared to clinical devices. The source of the noise could be a manufacturing issue (since the data are recorded wirelessly) or the fact that such experiments do not take place in an environment properly insulated from electromagnetic noise. Moreover, computers are necessary in order to design and execute a protocol for evoked response potentials (ERPs) experiments and the precision of the measurements and specifically issues of timing control depend critically on the computer hardware and software. In clinical and research systems specialized software and hardware for this purpose are available and they are the product of decades of highly specialized work. Very few such software exist today for research and clinical applications with wireless EEG systems in general although some simple tools are beginning to appear. The purpose of this thesis is to investigate whether a wireless EEG system like the Emotiv Epoc can be used with general-purpose computers to retrieve and record precise measurements in order to successfully conduct ERP experiments in general, focusing for the sake of an explicit example to an application for dyslexia, that is of interest to the host laboratory today.
7

Interfaces c?rebro-computador: estudo, design e desenvolvimento do jogo AdmiralMind Battleship

Ferreira, Alessandro Luiz Stamatto 28 March 2014 (has links)
Made available in DSpace on 2014-12-17T15:48:12Z (GMT). No. of bitstreams: 1 AlessandroLSF_DISSERT.pdf: 5359322 bytes, checksum: 38000f531a3025444d952f3756cbb61a (MD5) Previous issue date: 2014-03-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Interface C?rebro-Computador (ICC) ? uma ?rea que v?m sendo estudada h? d?cadas, mas apenas nos ?ltimos anos atingiu um n?vel de maturidade suficiente para permitir o seu uso com jogos digitais. Considerando que no futuro as ICCs far?o parte de sistemas interativos, ? preciso estudar o seu uso, avaliar quais s?o seus desafios e limita??es e, tamb?m, entender de forma mais apurada como adapt?-la para uso conjugado com outras formas usuais de intera??o humano-computador. Nesta pesquisa, investigamos apenas as ICCs n?o-invasivas por entendermos que esse tipo de ICC poder? ser, de fato, utilizada por usu?rios finais nesse novo paradigma de intera??o. Um dos grandes potenciais de uso de ICCs ? no dom?nio de jogos digitais, onde podem aumentar a imers?o e a divers?o atrav?s de um controle via ondas cerebrais. Apesar disso, nos dias atuais, ainda existem grandes dificuldades no processo de design e desenvolvimento de jogos dessa natureza. Como resultados da pesquisa destacamos o extenso levantamento da ?rea, a identifica??o de desafios de intera??o relacionados a ICCs, a identifica??o dos stakeholders atrav?s do referencial te?rico-metodol?gico da Semi?tica Organizacional, a confec??o de um design-rationale para apoiar o processo de design de jogos dessa natureza e, ainda, o design e a implementa??o em C++ de um jogo de batalha naval via uma ICC h?brida baseada em movimento imaginado para uso com o headset EEG Emotic EPOC
8

Asymmetry of Gains and Losses: Behavioral and Electrophysiological Measures

Flores, Diego Gonzalo 01 December 2016 (has links)
The purpose of this research was to explore the effects of small monetary or economic gains and/or losses on choice behavior through the use of a computerized game and to determine gain/loss ratio differences using both behavioral and electrophysiological measures. Participants (N=53) played the game in several 36 minute sessions. These sessions operated with concurrent variable-interval schedules for both rewards and penalties. Previously, asymmetrical effects of gains and losses have been identified through cognitive studies, primarily due to the work of nobel laureates Daniel Kahneman and Amos Tversky (1979). They found that the effect of a loss is twice (i.e., 2:1) that of a gain. Similar results have been observed in the behavioral laboratory as exemplified by the research of Rasmussen and Newland (2008), who found a 3:1 ratio for the effect of losses versus gains. The asymmetry of gains and losses was estimated behaviorally and through event-related brain potentials (ERPs) and the cognitive (Kahneman and Tversky) and behavioral (Rasmussen and Newland) discrepancy elucidated. In the game, the player moves an animated submarine around sea rocks to collect yellow coins and other treasures on the sea floor. Upon collecting a coin, one of three things can happen: The player triggers a penalty (loss), the player triggers a payoff (gain), or there is no change. The behavioral measures consisted in counting the number of clicks, reinforces, and punishers and then determining ratio differences between punished (loss) and no punished condition (gain) conditions. The obtained gain/loss ratio corresponded to an asymmetry of 2:1. Similarly ratio differences were found between male and female, virtual money and cash, risk averse versus risk seeking, and generosity versus profit behavior. Also, no ratio difference was found when players receive information about other player's performances in the game (players with information versus players without information). In electroencephalographic (EEG) studies, visual evoked potentials (VEPs) and ERPs components (e.g., P300) were examined. I found increased ERP amplitudes for the losses in relation to the gains that corresponded to the calculated behavioral asymmetry of 2:1. A correlational strategy was adopted that sought to identify neural correlates of choice consistent with cognitive and behavioral approaches. In addition, electro cortical ratio differences were observed between different sets of electrodes that corresponded to the front, middle, and back sections of the brain; differences between sessions, risk averse and risk seeking behavior and sessions with concurrent visual and auditory stimuli and only visual were also estimated.

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