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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.
21

Validation d’une vidéo d’animation pour l’évaluation visuelle de l’hémianopsie homonyme

Ferreri, Jeff 08 1900 (has links)
Mémoire de maîtrise présenté en vue de l'obtention de la maîtrise en psychologie (M. Sc) / Contexte : L’hémianopsie homonyme (HH) a un impact significatif sur les activités quotidiennes, et les méthodes actuelles d’évaluation des personnes ayant une amputation du champ visuel ne permettent pas de combiner l’évaluation de la vision centrale et périphérique. Objectifs : Cette étude visait à valider un film d’animation innovant comme nouvel outil d’évaluation pour mesurer l’étendue du champ visuel aveugle, à établir une norme auprès d’une population contrôle en bonne santé visuelle et à déterminer le niveau de faisabilité du test. Méthodologie : La vidéo d’animation présentait une série de personnages à détecter. Elle était présentée sur 160° répartis sur 3 moniteurs d’ordinateur. Un eye-tracker était utilisé pour vérifier la stabilisation de la tête et le contrôle de la fixation. Quarante participants en bonne santé, âgés de 18 à 75 ans, ont été recrutés. Résultats : La plupart des animations ont été perçues par des participants contrôle sains, ce qui a permis d’établir une norme pour le test. Concernant l’appréciation du test, 60 % des participants l’ont beaucoup apprécié, 29 % l’ont aimé et 11 % ont eu une opinion neutre. Conclusion : Cet outil écologique évalue simultanément la vision centrale et la vision périphérique à l’aide d’un film d’animation. Avec des normes établies à partir d’une population générale ayant une vision saine et un accueil positif des participants, cet outil pourrait être utilisé pour évaluer et dépister les personnes suspectées d’avoir une HH, en particulier chez les enfants. / Background: Homonymous hemianopia (HH) has a significant impact on daily activities, and current methods of assessing people with visual field amputation don’t combine assessment of central and peripheral vision. Objectives: The aim of this study was to validate an innovative animated film as a new assessment tool for measuring the extent of the blind visual field, to establish a standard in a visually healthy control population, and to determine the test’s feasibility. Methodology: The animated video presented a series of characters that needed to be detected. It was presented in 160 degrees on 3 computer monitors. An eye tracker was used to check head stabilization and fixation control. Forty healthy participants aged between 18 and 75 were recruited. Results: Most of the animations were perceived by healthy control participants, helping to establish a standard for the test. In terms of appreciation of the test, 60% of participants liked it a lot, 29% liked it and 11% had a neutral opinion. Conclusion: This ecological tool simultaneously assesses central and peripheral vision using an animated film. With standards based on a general population with healthy vision and a positive reception from participants, this tool could be used to assess and screen people suspected of having HH, particularly in children.
22

Look2Hook - A Comparative Study of Eye-tracker and Mouse Based Object Selection in a Complex Environment / Look2Hook - En Komparativ Studie av Eye-tracker och Musbaserad Objekt Selektion i en Komplex Miljö

Erlandsson, Oskar January 2021 (has links)
In this thesis the Tobii eye-tracker 4L was used to investigate how well eye-tracking solutions such as a confirmation-click and dwell-time algorithm compares to the standard mouse input device when performing selection tasks in a map environment. In order to distinguish the different complexity one could face, two user cases are proposed. Scenario one includes non clustered objects. Scenario two include clustered occluded objects. A user study with nine different participants where conducted in order to compare the execution times and find out how error prone the different methods were. Each test participant performed eight different tests, three in the non-clustered scenario and five in the clustered scenario. In two of the tests in the clustered scenario test participants were aided with zooming through a zoom algorithm. The methods was evaluated by calculating the average execution times and errors along with the corresponding standard deviations. In order to grasp the users experience a subjective cognitive load score was calculated with the help of a questionnaire. The eye-tracker methods was found to be competitive in comparison to mouse interaction in the more simple non-clustered case. However, in a more complex scenario such as the clustered case the mouse interaction had the lowest average completion time and cognitive load score. A different type of selection behaviour was discovered among the test participants in the clustered scenario due to the difference in precision between the eye-tracker and mouse interaction. Finally interesting areas to consider in the future is presented and discussed. / I denna avhandling användes en Tobii eye-tracker 4L för att undersöka hur väl eye-tracking metoder så som en bekräftelseklick och dwell-time algoritm jämför sig med standard mus interaktion vid objekt selektion i en kartmiljö. För att urskilja variationen i komplexitet man kan möta föreslås två olika användarfall. Scenario ett inkluderar objekt som är distinktivt separerade och därav ej grupperade. Scenario två inkluderar grupperade samt ockluderade objekt. En användarstudie med nio olika deltagare genomfördes för att jämföra exekveringstiderna och ta reda på hur felbenägna de olika metoderna var. Varje testdeltagare utförde åtta olika tester, tre i det icke-grupperade scenariot och fem i det grupperade scenariot. I två av testerna i det grupperade scenariot fick deltagarna hjälp med att zooma genom en zoomalgoritm. Metoderna utvärderades genom att beräkna de genomsnittliga exekveringstiderna samt antal fel tillsammans med motsvarande standardavvikelser. För att förstå hur användarna upplevde de olika metoderna togs en subjektiv kognitiv belastningspoäng fram genom ett frågeformulär. Eye-tracker metoderna var konkurrenskraftiga i jämförelse med musinteraktion i det enklare fallet där objekt ej var grupperade. I ett mer komplext scenario, såsom i det grupperade fallet, hade dock musinteraktionen den lägsta genomsnittliga exekveringstiden och kognitiva belastningspoängen. En annan typ av selektions beteende upptäcktes bland testdeltagarna i det grupperade scenariot på grund av skillnaden i precision mellan eye-trackern och musinteraktionen. Slutligen presenteras och diskuteras intressanta områden att överväga vid framtida arbeten.
23

Odpověď zrakového analyzátoru při řízení vozidla v reálných podmínkách a na simulátoru při paralelní motorické úloze. / The response of the visual system when driving a car in real conditions and in a simulator during a parallel motor task.

Čiháková, Lucie January 2011 (has links)
Work title: The response of the visual system when driving a car in real conditions and in a simulator during a parallel motor task. Aims: To implement a laboratory measurement in a driving simulator and in real conditions during a parallel motor task. To track the response of the visual system during the task and to determine potential differences in the response of the visual system and in the speed in the simulator and in the real car environment. Methods: The laboratory measurement was realized in a driving simulator OCTAVIA II. The measurement in real conditions was realized in Škoda Octavia as well. The eye-tracking method was used to track the drivers` eyes. Results: In the simulator the more experienced driver managed to do the parallel motor task within a shorter period of time than the less experienced driver, lower frequency of looks at the radio during the tasks with the more experienced driver was not proved. There was not an evidence of more balanced speed during the drive with the more experienced driver in the simulator. On the average the driver spent shorter time doing the tasks in the real environment than in the simulator and the total number of looks at the radio was lower. The speed of the drive in the real environment was lower than the speed in the simulator. Key words:...
24

Investigação experimental do Kindchenschema lorenziano: Preferência visual de portadores de Síndrome de Williams e Transtorno do Espectro Autista em resposta a imagens neotênicas faciais / Experimental investigation of the lorenzian Kindchenschema: visual preference of Williams Syndrome patients and Autistic Spectrum Disorder in response to neotenic facial images

Carvalho, André Paulo Correa de 11 December 2018 (has links)
A neotenia é um importante processo biológico-evolutivo que conserva traços fenotípicos do jovem no indivíduo adulto. A neotenia modifica a velocidade típica da ontogênese das características morfológicas compartilhadas pelos ancestrais. Essas mudanças podem representar oportunidades de mudanças fenotípicas dramáticas com poucas alterações genéticas, possibilitando alterações de estados especializados. O etólogo Konrad Lorenz reconheceu características neotênicas em humanos e algumas espécies de mamíferos na fórmula estrutural do corpo (principalmente da face) típica de infantes. Essa fórmula corpórea foi batizada por Lorenz de Kindchenschema. Os humanos típicos respondem quando observam traços infantis ativando uma resposta chamada de Efeito Kindchenschema (EK). Neste efeito verifica-se uma diminuição da agressividade, estimulação do cuidado parental e engajamento social. São raros os trabalhos de escaneamento do olhar em portadores de disfunções do neurodesenvolvimento, como a Síndrome de Williams (SW) e o Transtorno do Espectro Autista (TEA). O presente trabalho é o primeiro na literatura a investigar o escaneamento do olhar em portadores de SW e TEA usando estímulos faciais neotênicos de humanos e animais. Na presente investigação foram estudados 21 portadores de SW e 25 portadores de TEA, o grupo controle (GC) contou com 33 participantes. Encontramos uma correspondência entre os resultados declarados do estímulo preferido e o tempo de fixação. Os resultados mostraram que todos os participantes fixaram mais a região dos olhos de humanos e animais, sendo que o GC fixou mais tempo do que os portadores de SW e TEA. Foi possível separar usando o tempo de fixação nos olhos e HeatMaps os três grupos investigados. É viável a produção de um exame clínico auxiliar rápido e não-invasivo para indivíduos com suspeita de uma disfunção do neurodesenvolvimento. Talvez a região do nariz e boca sejam menos importantes e as orelhas mais importantes do que pensávamos nos estímulos neotênicos. Os estímulos mais neotênicos de infantes humanos e animais produziram um padrão semelhantes do tempo de fixação nos três grupos estudados. Esses resultados demonstram que portadores de SW e TEA respondem positivamente a estímulos faciais neotênicos. Sugerimos que as novas investigações na área incorporem também como variáveis faciais as orelhas, cor do cabelo e olhos, e simetria facial / Neoteny is an important biological-evolutionary process that retains phenotypic traits of the young in the adult individual of a species. Neoteny modifies the typical ontogeny velocity of the morphological characteristics shared with the ancestors. These changes may represent opportunities for dramatic phenotype modifications with few genetic changes, allowing for alterations in specialized states. The ethologist Konrad Lorenz has recognized neotenic characteristics in humans and some species of mammals in the structural formula of the body (mainly of the face) typical of infants. This body formula was named by Lorenz Kindchenschema. Typical humans respond when they observe infant traits by activating a response called the Kindchenschema Effect (KE). In this effect, there is a decrease in aggressiveness, stimulation of parental care and social engagement. There is a paucity of eye scanning in individuals with neurodevelopmental disorders such as Williams Syndrome (WS) and Autistic Spectrum Disorder (ASD). The present work is the first in the literature to investigate the eye scanning in WS and ASD patients using neotenic facial stimuli of humans and animals. In the present investigation, 21 WS and 25 ASD participants were studied. The control group (CG) had 33 participants. We found a correspondence between the stated results of the preferred stimulus and the fixation time. The results showed that all the participants fixed more the region of the eyes of humans and animals, and the CG fixed more time than the WS and ASD participants. It was possible to distinguish, using the fixation time in the eyes and Heat Maps, the three groups. The production of a rapid and non-invasive auxiliary clinical examination is feasible for individuals suspected in presenting a neurodevelopmental dysfunction. Perhaps the nose and mouth areas are less important, and the ears are more important than previously considered with respect. The more neotenic stimuli of human and animal infants produced a similar pattern of fixation time in the three groups studied. This may represent a greater adaptive value than we thought of those with WS and ASD. We suggest that the new investigations can also incorporate facial variables as ears, hair color and eyes, and facial symmetry
25

Investigação experimental do Kindchenschema lorenziano: Preferência visual de portadores de Síndrome de Williams e Transtorno do Espectro Autista em resposta a imagens neotênicas faciais / Experimental investigation of the lorenzian Kindchenschema: visual preference of Williams Syndrome patients and Autistic Spectrum Disorder in response to neotenic facial images

André Paulo Correa de Carvalho 11 December 2018 (has links)
A neotenia é um importante processo biológico-evolutivo que conserva traços fenotípicos do jovem no indivíduo adulto. A neotenia modifica a velocidade típica da ontogênese das características morfológicas compartilhadas pelos ancestrais. Essas mudanças podem representar oportunidades de mudanças fenotípicas dramáticas com poucas alterações genéticas, possibilitando alterações de estados especializados. O etólogo Konrad Lorenz reconheceu características neotênicas em humanos e algumas espécies de mamíferos na fórmula estrutural do corpo (principalmente da face) típica de infantes. Essa fórmula corpórea foi batizada por Lorenz de Kindchenschema. Os humanos típicos respondem quando observam traços infantis ativando uma resposta chamada de Efeito Kindchenschema (EK). Neste efeito verifica-se uma diminuição da agressividade, estimulação do cuidado parental e engajamento social. São raros os trabalhos de escaneamento do olhar em portadores de disfunções do neurodesenvolvimento, como a Síndrome de Williams (SW) e o Transtorno do Espectro Autista (TEA). O presente trabalho é o primeiro na literatura a investigar o escaneamento do olhar em portadores de SW e TEA usando estímulos faciais neotênicos de humanos e animais. Na presente investigação foram estudados 21 portadores de SW e 25 portadores de TEA, o grupo controle (GC) contou com 33 participantes. Encontramos uma correspondência entre os resultados declarados do estímulo preferido e o tempo de fixação. Os resultados mostraram que todos os participantes fixaram mais a região dos olhos de humanos e animais, sendo que o GC fixou mais tempo do que os portadores de SW e TEA. Foi possível separar usando o tempo de fixação nos olhos e HeatMaps os três grupos investigados. É viável a produção de um exame clínico auxiliar rápido e não-invasivo para indivíduos com suspeita de uma disfunção do neurodesenvolvimento. Talvez a região do nariz e boca sejam menos importantes e as orelhas mais importantes do que pensávamos nos estímulos neotênicos. Os estímulos mais neotênicos de infantes humanos e animais produziram um padrão semelhantes do tempo de fixação nos três grupos estudados. Esses resultados demonstram que portadores de SW e TEA respondem positivamente a estímulos faciais neotênicos. Sugerimos que as novas investigações na área incorporem também como variáveis faciais as orelhas, cor do cabelo e olhos, e simetria facial / Neoteny is an important biological-evolutionary process that retains phenotypic traits of the young in the adult individual of a species. Neoteny modifies the typical ontogeny velocity of the morphological characteristics shared with the ancestors. These changes may represent opportunities for dramatic phenotype modifications with few genetic changes, allowing for alterations in specialized states. The ethologist Konrad Lorenz has recognized neotenic characteristics in humans and some species of mammals in the structural formula of the body (mainly of the face) typical of infants. This body formula was named by Lorenz Kindchenschema. Typical humans respond when they observe infant traits by activating a response called the Kindchenschema Effect (KE). In this effect, there is a decrease in aggressiveness, stimulation of parental care and social engagement. There is a paucity of eye scanning in individuals with neurodevelopmental disorders such as Williams Syndrome (WS) and Autistic Spectrum Disorder (ASD). The present work is the first in the literature to investigate the eye scanning in WS and ASD patients using neotenic facial stimuli of humans and animals. In the present investigation, 21 WS and 25 ASD participants were studied. The control group (CG) had 33 participants. We found a correspondence between the stated results of the preferred stimulus and the fixation time. The results showed that all the participants fixed more the region of the eyes of humans and animals, and the CG fixed more time than the WS and ASD participants. It was possible to distinguish, using the fixation time in the eyes and Heat Maps, the three groups. The production of a rapid and non-invasive auxiliary clinical examination is feasible for individuals suspected in presenting a neurodevelopmental dysfunction. Perhaps the nose and mouth areas are less important, and the ears are more important than previously considered with respect. The more neotenic stimuli of human and animal infants produced a similar pattern of fixation time in the three groups studied. This may represent a greater adaptive value than we thought of those with WS and ASD. We suggest that the new investigations can also incorporate facial variables as ears, hair color and eyes, and facial symmetry
26

Eye Gaze and Cortisol Levels in Socially Anxious Young Adults During an Interactive Real World Task

Colson, Chelsea M. 01 May 2018 (has links)
Social anxiety is a disorder where people fear social interactions and is associated with physiological changes. Eye tracking studies have shown that people with social anxiety spent more time gazing at emotional faces presented on a computer screen and spent more time gazing at the eye region. There has been limited studies on tracking eye gaze in a real-life setting interacting with another person. We used a wearable eye tracker during a brief one-on-one interview about participants’ challenges faced at work or school. Along with self-report psychological measures about social anxiety and shyness, we also measured participants’ salivary cortisol as a metric for physiological stress. We hypothesized that socially anxious individuals would have higher cortisol levels and spent more time gazing at the face. However, there was no change in cortisol levels before and after the interview. In addition, socially anxious individuals had lower cortisol levels than less anxious people. Furthermore, the time spent fixating on the region of interest (ROI), which was the face, was not correlated with social anxiety, anxiety or shyness. Paradoxically, the more socially anxious participants seem to have had a lower physiological stress response than less socially anxious participants.
27

DIGITAL INPAINTING ALGORITHMS AND EVALUATION

Mahalingam, Vijay Venkatesh 01 January 2010 (has links)
Digital inpainting is the technique of filling in the missing regions of an image or a video using information from surrounding area. This technique has found widespread use in applications such as restoration, error recovery, multimedia editing, and video privacy protection. This dissertation addresses three significant challenges associated with the existing and emerging inpainting algorithms and applications. The three key areas of impact are 1) Structure completion for image inpainting algorithms, 2) Fast and efficient object based video inpainting framework and 3) Perceptual evaluation of large area image inpainting algorithms. One of the main approach of existing image inpainting algorithms in completing the missing information is to follow a two stage process. A structure completion step, to complete the boundaries of regions in the hole area, followed by texture completion process using advanced texture synthesis methods. While the texture synthesis stage is important, it can be argued that structure completion aspect is a vital component in improving the perceptual image inpainting quality. To this end, we introduce a global structure completion algorithm for completion of missing boundaries using symmetry as the key feature. While existing methods for symmetry completion require a-priori information, our method takes a non-parametric approach by utilizing the invariant nature of curvature to complete missing boundaries. Turning our attention from image to video inpainting, we readily observe that existing video inpainting techniques have evolved as an extension of image inpainting techniques. As a result, they suffer from various shortcoming including, among others, inability to handle large missing spatio-temporal regions, significantly slow execution time making it impractical for interactive use and presence of temporal and spatial artifacts. To address these major challenges, we propose a fundamentally different method based on object based framework for improving the performance of video inpainting algorithms. We introduce a modular inpainting scheme in which we first segment the video into constituent objects by using acquired background models followed by inpainting of static background regions and dynamic foreground regions. For static background region inpainting, we use a simple background replacement and occasional image inpainting. To inpaint dynamic moving foreground regions, we introduce a novel sliding-window based dissimilarity measure in a dynamic programming framework. This technique can effectively inpaint large regions of occlusions, inpaint objects that are completely missing for several frames, change in size and pose and has minimal blurring and motion artifacts. Finally we direct our focus on experimental studies related to perceptual quality evaluation of large area image inpainting algorithms. The perceptual quality of large area inpainting technique is inherently a subjective process and yet no previous research has been carried out by taking the subjective nature of the Human Visual System (HVS). We perform subjective experiments using eye-tracking device involving 24 subjects to analyze the effect of inpainting on human gaze. We experimentally show that the presence of inpainting artifacts directly impacts the gaze of an unbiased observer and this in effect has a direct bearing on the subjective rating of the observer. Specifically, we show that the gaze energy in the hole regions of an inpainted image show marked deviations from normal behavior when the inpainting artifacts are readily apparent.
28

Ανάκτηση εικόνας βάσει υφής με χρήση Eye tracker / A texture based image retrieval technique using Eye tracker

Καραδήμας, Ηλίας 11 January 2011 (has links)
Η ραγδαία αύξηση των εικόνων, σε συνδυασμό με την αδυναμία των συστημάτων ανάκτησης εικόνας βάσει περιεχομένου να εξάγουν σημασιολογικά χαρακτηριστικά, οδήγησαν στην εισαγωγή του ανθρώπινου παράγοντα στην πειραματική διαδικασία. Ένας πολύ συνηθισμένος και επιτυχημένος τρόπος χρησιμοποίησης του ανθρώπινου συστήματος όρασης είναι μέσω της καταγραφής των οφθαλμικών κινήσεων. Στο σύστημα ανάκτησης το οποίο προτείνεται στην παρούσα εργασία γίνεται καταγραφή των σημείων εστίασης που προέκυψαν κατά την παρατήρηση των εικόνων βάσεως. Από τα σημεία αυτά, γίνεται εξαγωγή χαρακτηριστικών υφής με δύο μεθόδους, τα φίλτρα Gabor και το διακριτό μετασχηματισμό συνημιτόνου (DCT), παράγοντας πολυδιάστατα διανύσματα. Τα διανύσματα αυτά συγκρίνονται ανά δύο μέσω του μη παραμετρικού WW test, δημιουργώντας έναν πίνακα αποστάσεων. Με την εισαγωγή μιας ζητούμενης εικόνας στο σύστημα, τα χαρακτηριστικά υφής της συγκρίνονται με αυτά της βάσης προσθέτοντας μια επιπλέον διάσταση στον πίνακα απόστασης. Η απεικόνιση της σχέσης μεταξύ όλων των εικόνων (συμπεριλαμβανομένης και της αιτούμενης) γίνεται σε ένα χάρτη τριών διαστάσεων μέσω πολυδιάστατης κλιμάκωσης (MDS αλγόριθμος). Τα αποτελέσματα τα οποία προέρχονται από τα φίλτρα Gabor παρουσιάζουν μεγαλύτερη αξιοπιστία, κάνοντας εφικτή την επέκταση του συστήματος με χρήση μίας μεγαλύτερης βάσης εικόνων. / The rapid increase of images, combined with the weakness of the Content Based Image Retrieval (CBIR) systems to extract semantic features, led to the introduction of the human factor into the experimental procedure. A very common and successful way of using the human vision system is through the record of eye movements. In the retrieval system which is proposed in the present thesis, the fixation points that arose from viewing the database images are recorded. From these points, the texture features are extracted using two methods, Gabor filters and Discrete Cosine Transform (DCT), producing multidimensional vectors. These vectors are compared through the non parametric WW test, creating a distance matrix. By producing a query image in the system, its’ texture features are compared to those of the database, adding an extra dimension to the distance matrix. The visual representation of the relation among all the images (query image included), is depicted in a three dimensional map using multidimensional scaling (MDS algorithm). The results obtained from Gabor filters are characterized by higher robustness, making the expansion of the system possible, by using a bigger image database.
29

Využití IT při analýze působení outdoorové reklamy / The application of IT for analysis of outdoor advertising effects

Jeníčková, Tereza January 2009 (has links)
This thesis deals with use of Information technology for analysis of exposure to advertising communications, focusing on outdoor advertising.In the theoretical part is a brief outline of the beginnings and development of advertising, its effects on people, whether it can change their consumption behaviour, its position in the modern world and the way new technology along with psychology can be used for its analysis. The second part gives insight in the practical research of effects of outdoor advertising on people. There is an approach of Eye Camera technology in praxis, preparation for research, problems solved in its course. Data obtained are both verbally and graphically interpreted.
30

Rysy z eye-trackeru v syntaktickém parsingu / Eye-tracking features in syntactic parsing

Agrawal, Abhishek January 2020 (has links)
In this thesis, we explore the potential benefits of leveraging eye-tracking information for dependency parsing on the English part of the Dundee corpus. To achieve this, we cast dependency parsing as a sequence labelling task and then augment the neural model for sequence labelling with eye-tracking features. We also augment a graph-based parser with eye-tracking features and parse the Dundee Corpus to corroborate our findings from the sequence labelling parser. We then experiment with a variety of parser setups ranging from parsing with all features to a delexicalized parser. Our experiments show that for a parser with all features, although the improvements are positive for the LAS score they are not significant whereas our delexicalized parser significantly outperforms the baseline we established. We also analyze the contribution of various eye-tracking features towards the different parser setups and find that eye-tracking features contain information which is complementary in nature, thus implying that augmenting the parser with various gaze features grouped together provides better performance than any individual gaze feature. 1

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