63 research outputs found

    Adaptive Methods for Color Vision Impaired Users

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    Color plays a key role in the understanding of the information in computer environments. It happens that about 5% of the world population is affected by color vision deficiency (CVD), also called color blindness. This visual impairment hampers the color perception, ending up by limiting the overall perception that CVD people have about the surrounding environment, no matter it is real or virtual. In fact, a CVD individual may not distinguish between two different colors, what often originates confusion or a biased understanding of the reality, including web environments, whose web pages are plenty of media elements like text, still images, video, sprites, and so on. Aware of the difficulties that color-blind people may face in interpreting colored contents, a significant number of recoloring algorithms have been proposed in the literature with the purpose of improving the visual perception of those people somehow. However, most of those algorithms lack a systematic study of subjective assessment, what undermines their validity, not to say usefulness. Thus, in the sequel of the research work behind this Ph.D. thesis, the central question that needs to be answered is whether recoloring algorithms are of any usefulness and help for colorblind people or not. With this in mind, we conceived a few preliminary recoloring algorithms that were published in conference proceedings elsewhere. Except the algorithm detailed in Chapter 3, these conference algorithms are not described in this thesis, though they have been important to engender those presented here. The first algorithm (Chapter 3) was designed and implemented for people with dichromacy to improve their color perception. The idea is to project the reddish hues onto other hues that are perceived more regularly by dichromat people. The second algorithm (Chapter 4) is also intended for people with dichromacy to improve their perception of color, but its applicability covers the adaptation of text and image, in HTML5- compliant web environments. This enhancement of color contrast of text and imaging in web pages is done while keeping the naturalness of color as much as possible. Also, to the best of our knowledge, this is the first web recoloring approach targeted to dichromat people that takes into consideration both text and image recoloring in an integrated manner. The third algorithm (Chapter 5) primarily focuses on the enhancement of some of the object contours in still images, instead of recoloring the pixels of the regions bounded by such contours. Enhancing contours is particularly suited to increase contrast in images, where we find adjacent regions that are color indistinguishable from dichromat’s point of view. To our best knowledge, this is one of the first algorithms that take advantage of image analysis and processing techniques for region contours. After accurate subjective assessment studies for color-blind people, we concluded that the CVD adaptation methods are useful in general. Nevertheless, each method is not efficient enough to adapt all sorts of images, that is, the adequacy of each method depends on the type of image (photo-images, graphical representations, etc.). Furthermore, we noted that the experience-based perceptual learning of colorblind people throughout their lives determines their visual perception. That is, color adaptation algorithms must satisfy requirements such as color naturalness and consistency, to ensure that dichromat people improve their visual perception without artifacts. On the other hand, CVD adaptation algorithms should be object-oriented, instead of pixel-oriented (as typically done), to select judiciously pixels that should be adapted. This perspective opens an opportunity window for future research in color accessibility in the field of in human-computer interaction (HCI).A cor desempenha um papel fundamental na compreensão da informação em ambientes computacionais. Porém, cerca de 5% da população mundial é afetada pela deficiência de visão de cor (ou Color Vision Deficiency (CVD), do Inglês), correntemente designada por daltonismo. Esta insuficiência visual dificulta a perceção das cores, o que limita a perceção geral que os indivíduos têm sobre o meio, seja real ou virtual. Efetivamente, um indivíduo com CVD vê como iguais cores que são diferentes, o que origina confusão ou uma compreensão distorcida da realidade, assim como dos ambientes web, onde existe uma abundância de conteúdos média coloridos, como texto, imagens fixas e vídeo, entre outros. Com o intuito de mitigar as dificuldades que as pessoas com CVD enfrentam na interpretação de conteúdos coloridos, tem sido proposto na literatura um número significativo de algoritmos de recoloração, que têm como o objetivo melhorar, de alguma forma, a perceção visual de pessoas com CVD. Porém, a maioria desses trabalhos carece de um estudo sistemático de avaliação subjetiva, o que põe em causa a sua validação, se não mesmo a sua utilidade. Assim, a principal questão à qual se pretende responder, como resultado do trabalho de investigação subjacente a esta tese de doutoramento, é se os algoritmos de recoloração têm ou não uma real utilidade, constituindo assim uma ajuda efetiva às pessoas com daltonismo. Tendo em mente esta questão, concebemos alguns algoritmos de recoloração preliminares que foram publicados em atas de conferências. Com exceção do algoritmo descrito no Capítulo 3, esses algoritmos não são descritos nesta tese, não obstante a sua importância na conceção daqueles descritos nesta dissertação. O primeiro algoritmo (Capítulo 3) foi projetado e implementado para pessoas com dicromacia, a fim de melhorar a sua perceção da cor. A ideia consiste em projetar as cores de matiz avermelhada em matizes que são melhor percebidos pelas pessoas com os tipos de daltonismo em causa. O segundo algoritmo (Capítulo 4) também se destina a melhorar a perceção da cor por parte de pessoas com dicromacia, porém a sua aplicabilidade abrange a adaptação de texto e imagem, em ambientes web compatíveis com HTML5. Isto é conseguido através do realce do contraste de cores em blocos de texto e em imagens, em páginas da web, mantendo a naturalidade da cor tanto quanto possível. Além disso, tanto quanto sabemos, esta é a primeira abordagem de recoloração em ambiente web para pessoas com dicromacia, que trata o texto e a imagem de forma integrada. O terceiro algoritmo (Capítulo 5) centra-se principalmente na melhoria de alguns dos contornos de objetos em imagens, em vez de aplicar a recoloração aos pixels das regiões delimitadas por esses contornos. Esta abordagem é particularmente adequada para aumentar o contraste em imagens, quando existem regiões adjacentes que são de cor indistinguível sob a perspetiva dos observadores com dicromacia. Também neste caso, e tanto quanto é do nosso conhecimento, este é um dos primeiros algoritmos em que se recorre a técnicas de análise e processamento de contornos de regiões. Após rigorosos estudos de avaliação subjetiva com pessoas com daltonismo, concluiu-se que os métodos de adaptação CVD são úteis em geral. No entanto, cada método não é suficientemente eficiente para todos os tipo de imagens, isto é, o desempenho de cada método depende do tipo de imagem (fotografias, representações gráficas, etc.). Além disso, notámos que a aprendizagem perceptual baseada na experiência das pessoas daltónicas ao longo de suas vidas é determinante para perceber aquilo que vêem. Isto significa que os algoritmos de adaptação de cor devem satisfazer requisitos tais como a naturalidade e a consistência da cor, de modo a não pôr em causa aquilo que os destinatários consideram razoável ver no mundo real. Por outro lado, a abordagem seguida na adaptação CVD deve ser orientada aos objetos, em vez de ser orientada aos pixéis (como tem sido feito até ao momento), de forma a possibilitar uma seleção mais criteriosa dos pixéis que deverão ser sujeitos ao processo de adaptação. Esta perspectiva abre uma janela de oportunidade para futura investigação em acessibilidade da cor no domínio da interacção humano-computador (HCI)

    Modern Education and Computer Science

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    Abstract -Adaptive learning technology allows for the development of more personalized online learning experiences with materials that adapt to student performance and skill level

    Assisted Interaction for Improving Web Accessibility: An Approach Driven and Tested by Userswith Disabilities

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    148 p.Un porcentaje cada vez mayor de la población mundial depende de la Web para trabajar, socializar, opara informarse entre otras muchas actividades. Los beneficios de la Web son todavía más cruciales paralas personas con discapacidades ya que les permite realizar un sinfín de tareas que en el mundo físico lesestán restringidas debido distintas barreras de accesibilidad. A pesar de sus ventajas, la mayoría depáginas web suelen ignoran las necesidades especiales de las personas con discapacidad, e incluyen undiseño único para todos los usuarios. Existen diversos métodos para combatir este problema, como porejemplo los sistemas de ¿transcoding¿, que transforman automáticamente páginas web inaccesibles enaccesibles. Para mejorar la accesibilidad web a grupos específicos de personas, estos métodos requiereninformación sobre las técnicas de adaptación más adecuadas que deben aplicarse.En esta tesis se han realizado una serie de estudios sobre la idoneidad de diversas técnicas de adaptaciónpara mejorar la navegación web para dos grupos diferentes de personas con discapacidad: personas conmovilidad reducida en miembros superiores y personas con baja visión. Basado en revisionesbibliográficas y estudios observacionales, se han desarrollado diferentes adaptaciones de interfaces web ytécnicas alternativas de interacción, que posteriormente han sido evaluadas a lo largo de varios estudioscon usuarios con necesidades especiales. Mediante análisis cualitativos y cuantitativos del rendimiento yla satisfacción de los participantes, se han evaluado diversas adaptaciones de interfaz y métodosalternativos de interacción. Los resultados han demostrado que las técnicas probadas mejoran el acceso ala Web y que los beneficios varían según la tecnología asistiva usada para acceder al ordenador

    Developing Accessible Collection and Presentation Methods for Observational Data

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    The processes of collecting, cleaning, and presenting data are critical in ensuring the proper analysis of data at a later date. An opportunity exists to enhance the data collection and presentation process for those who are not data scientists – such as healthcare professionals and businesspeople interested in using data to help them make decisions. In this work, creating an observational data collection and presentation tool is investigated, with a focus on developing a tool prioritizing user-friendliness and context preservation of the data collected. This aim is achieved via the integration of three approaches to data collection and presentation.In the first approach, the collection of observational data is structured and carried out via a trichotomous, tailored, sub-branching scoring (TTSS) system. The system allows for deep levels of data collection while enabling data to be summarized quickly by a user via collapsing details. The system is evaluated against the stated requirements of usability and extensibility, proving the latter by providing examples of various evaluations created using the TTSS framework.Next, this approach is integrated with automated data collection via mobile device sensors, to facilitate the efficient completion of the assessment. Results are presented from a system used to combine the capture of complex data from the built environment and compare the results of the data collection, including how the system uses quantitative measures specifically. This approach is evaluated against other solutions for obtaining data about the accessibility of a built environment, and several assessments taken in the field are compared to illustrate the system’s flexibility. The extension of the system for automated data capture is also discussed.Finally, the use of accessibility information for data context preservation is integrated. This approach is evaluated via investigation of how accessible media entries improve the quality of search for an archival website. Human-generated accessibility information is compared to computer-generated accessibility information, as well as simple reliance on titles/metadata. This is followed by a discussion of how improved accessibility can benefit the understanding of gathered observational data’s context

    Human Computer Interaction and Emerging Technologies

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    The INTERACT Conferences are an important platform for researchers and practitioners in the field of human-computer interaction (HCI) to showcase their work. They are organised biennially by the International Federation for Information Processing (IFIP) Technical Committee on Human–Computer Interaction (IFIP TC13), an international committee of 30 member national societies and nine Working Groups. INTERACT is truly international in its spirit and has attracted researchers from several countries and cultures. With an emphasis on inclusiveness, it works to lower the barriers that prevent people in developing countries from participating in conferences. As a multidisciplinary field, HCI requires interaction and discussion among diverse people with different interests and backgrounds. The 17th IFIP TC13 International Conference on Human-Computer Interaction (INTERACT 2019) took place during 2-6 September 2019 in Paphos, Cyprus. The conference was held at the Coral Beach Hotel Resort, and was co-sponsored by the Cyprus University of Technology and Tallinn University, in cooperation with ACM and ACM SIGCHI. This volume contains the Adjunct Proceedings to the 17th INTERACT Conference, comprising a series of selected papers from workshops, the Student Design Consortium and the Doctoral Consortium. The volume follows the INTERACT conference tradition of submitting adjunct papers after the main publication deadline, to be published by a University Press with a connection to the conference itself. In this case, both the Adjunct Proceedings Chair of the conference, Dr Usashi Chatterjee, and the lead Editor of this volume, Dr Fernando Loizides, work at Cardiff University which is the home of Cardiff University Press

    Methods and techniques for analyzing human factors facets on drivers

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    Mención Internacional en el título de doctorWith millions of cars moving daily, driving is the most performed activity worldwide. Unfortunately, according to the World Health Organization (WHO), every year, around 1.35 million people worldwide die from road traffic accidents and, in addition, between 20 and 50 million people are injured, placing road traffic accidents as the second leading cause of death among people between the ages of 5 and 29. According to WHO, human errors, such as speeding, driving under the influence of drugs, fatigue, or distractions at the wheel, are the underlying cause of most road accidents. Global reports on road safety such as "Road safety in the European Union. Trends, statistics, and main challenges" prepared by the European Commission in 2018 presented a statistical analysis that related road accident mortality rates and periods segmented by hours and days of the week. This report revealed that the highest incidence of mortality occurs regularly in the afternoons during working days, coinciding with the period when the volume of traffic increases and when any human error is much more likely to cause a traffic accident. Accordingly, mitigating human errors in driving is a challenge, and there is currently a growing trend in the proposal for technological solutions intended to integrate driver information into advanced driving systems to improve driver performance and ergonomics. The study of human factors in the field of driving is a multidisciplinary field in which several areas of knowledge converge, among which stand out psychology, physiology, instrumentation, signal treatment, machine learning, the integration of information and communication technologies (ICTs), and the design of human-machine communication interfaces. The main objective of this thesis is to exploit knowledge related to the different facets of human factors in the field of driving. Specific objectives include identifying tasks related to driving, the detection of unfavorable cognitive states in the driver, such as stress, and, transversely, the proposal for an architecture for the integration and coordination of driver monitoring systems with other active safety systems. It should be noted that the specific objectives address the critical aspects in each of the issues to be addressed. Identifying driving-related tasks is one of the primary aspects of the conceptual framework of driver modeling. Identifying maneuvers that a driver performs requires training beforehand a model with examples of each maneuver to be identified. To this end, a methodology was established to form a data set in which a relationship is established between the handling of the driving controls (steering wheel, pedals, gear lever, and turn indicators) and a series of adequately identified maneuvers. This methodology consisted of designing different driving scenarios in a realistic driving simulator for each type of maneuver, including stop, overtaking, turns, and specific maneuvers such as U-turn and three-point turn. From the perspective of detecting unfavorable cognitive states in the driver, stress can damage cognitive faculties, causing failures in the decision-making process. Physiological signals such as measurements derived from the heart rhythm or the change of electrical properties of the skin are reliable indicators when assessing whether a person is going through an episode of acute stress. However, the detection of stress patterns is still an open problem. Despite advances in sensor design for the non-invasive collection of physiological signals, certain factors prevent reaching models capable of detecting stress patterns in any subject. This thesis addresses two aspects of stress detection: the collection of physiological values during stress elicitation through laboratory techniques such as the Stroop effect and driving tests; and the detection of stress by designing a process flow based on unsupervised learning techniques, delving into the problems associated with the variability of intra- and inter-individual physiological measures that prevent the achievement of generalist models. Finally, in addition to developing models that address the different aspects of monitoring, the orchestration of monitoring systems and active safety systems is a transversal and essential aspect in improving safety, ergonomics, and driving experience. Both from the perspective of integration into test platforms and integration into final systems, the problem of deploying multiple active safety systems lies in the adoption of monolithic models where the system-specific functionality is run in isolation, without considering aspects such as cooperation and interoperability with other safety systems. This thesis addresses the problem of the development of more complex systems where monitoring systems condition the operability of multiple active safety systems. To this end, a mediation architecture is proposed to coordinate the reception and delivery of data flows generated by the various systems involved, including external sensors (lasers, external cameras), cabin sensors (cameras, smartwatches), detection models, deliberative models, delivery systems and machine-human communication interfaces. Ontology-based data modeling plays a crucial role in structuring all this information and consolidating the semantic representation of the driving scene, thus allowing the development of models based on data fusion.I would like to thank the Ministry of Economy and Competitiveness for granting me the predoctoral fellowship BES-2016-078143 corresponding to the project TRA2015-63708-R, which provided me the opportunity of conducting all my Ph. D activities, including completing an international internship.Programa de Doctorado en Ciencia y Tecnología Informática por la Universidad Carlos III de MadridPresidente: José María Armingol Moreno.- Secretario: Felipe Jiménez Alonso.- Vocal: Luis Mart

    Usability Tool Support for Model-Based Web Development

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    When web engineering methods are used for the development of web applications, models are created during the development process which describe the website. Using the information present in these models, it is possible to create usability tool support that is more advanced than current approaches, which do not rely on the presence of models. This dissertation presents ideas for tool support during different phases of the development, such as the implementation phase or the testing phase. For example, if a tool knows from a model that the audience of a website are teenagers, it can examine whether the words and sentences used on the website are likely to be understood by teenagers. An approach is presented to augment existing web engineering models with the additional information ("age" in this case) and to make it available to tools, e.g. via embedding it in HTML code. Two prototypes demonstrate the concepts for integrating usability tool support into web engineering

    The Pull Paradigm : foundations of user-centric advanced driver assistant systems based on bidirectional car2X communication

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    This thesis develops applications for vehicular ad-hoc networks that go far beyond the currently established areas of driving safety and traffic efficiency. The ad-hoc network is regarded as a dynamic information resource which is available to any vehicle at any time. In contrast to current state-of-the-art research, the proposed Pull Paradigm starts at the user\u27s vehicle rather than at an information source somewhere in the network, e.g. a braking car. To access information from highly dynamic ad-hoc networks, bidirectional communication and information discovery and retrieval play a vital role. Therefore, in the course of the work, the applicability of the Pull Paradigm to established vehicular ad-hoc networks is thoroughly examined and missing aspects are identified. It turns out that a number of enhancements to almost all layers of the network stack are necessary in order to apply the Pull Paradigm using existing technology. The central elements here are two novel algorithms for managing information flow and dissemination in ad-hoc networks, which are at first formulated from the abstract perspective of graph theory. Using the knowledge gained leads to the development of PADE, a platform that supports development of vehicular ad-hoc network applications. The designed algorithms are then implemented as a routing scheme, integrated and evaluated in large, simulated city scenarios. Furthermore, PADE combines real\u27\u27 and simulated communication technologies and abstracts from them, so that applications can be transferred from the lab into a test vehicle with minimal effort. In order to achieve this ambitious goal, PADE builds on a number of existing simulation and communication technologies. The practical applicability of the Pull approach is shown in two demonstrators that are integrated into a BMW 5 series test vehicle. The presentation module of the PADE platform was tested in the currently largest field operational test for vehicular ad-hoc communication. Over 400 drivers in 120 vehicles experienced the system on a daily basis.In dieser Doktorarbeit werden Anwendungen für Fahrzeug Ad-hoc Netzwerke erarbeitet, die weit über die derzeit etablierten Bereiche der Fahrsicherheit und Verkehrseffizienz hinausgehen. Das Ad-hoc Netzwerk wird dabei als dynamische Informationsressource angesehen, die jedem Fahrzeug zu jedem Zeitpunkt zur Verfügung steht. Im Gegensatz zum derzeitigen Stand der Forschung geht das vorgestellte Pull Paradigma vom Fahrzeug des Benutzers und nicht von der Informationsquelle aus, z.B. einem bremsenden Fahrzeug. Für den Zugriff auf Informationen aus hochdynamischen Ad-hoc Netzen, spielen bidirektionale Kommunikation, Informationssuche und -rücktransport eine entscheidende Rolle. Im Verlauf der Arbeit wird deshalb die Anwendbarkeit des Pull Paradigmas auf etablierte Fahrzeug Ad-hoc Netze untersucht und fehlende Aspekte identifiziert. Es zeigt sich, dass eine Reihe an Erweiterungen auf fast allen Ebenen des Netzwerkstapels nötig sind damit die bestehende Technologie um das Pull Paradigma erweitert werden kann. Zentraler Punkt hierbei sind zwei neuartige Algorithmen zur Informationsverwaltung und -verbreitung in Ad-hoc Netzwerken die zunächst abstrakt aus Sicht der Graphentheorie formuliert werden. Mit Hilfe der gewonnenen Erkenntnisse wird PADE, eine Plattform zur Entwicklung von Anwendungen für Fahrzeug Ad-hoc Netze, entwickelt. Die entworfenen Algorithmen werden dann als Routingverfahren im Netzwerkstapel realisiert, in diesen integriert und auf großflächigen Stadtszenarien im Simulator evaluiert. Des Weiteren vereint PADE echte\u27\u27 und simulierte Kommunikationstechnologien und abstrahiert von diesen, sodass Anwendungen mit minimalem Aufwand vom Labor in ein Testfahrzeug überführt werden können. Um dieses ambitionierte Ziel zu erreichen, wird auf einer Reihe bereits bestehender Simulations- und Kommunikationstechnologien aufgebaut. Die praktische Anwendbarkeit des Pull Paradigmas wird anschließend in zwei Demonstratoren implementiert und in ein BMW 5er Testfahrzeug integriert. Das Präsentationsmodul der PADE Plattform wurde im derzeit weltgrößten Feldversuch für Fahrzeug Ad-hoc Kommunikation von über 400 Fahrern in 120 Fahrzeugen im Alltag getestet

    Persuasive by design: a model and toolkit for designing evidence-based interventions

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