Le développement des systèmes de communication et de localisation et les progrès des dispositifs mobiles rendent possible la mise en œuvre de nouvelles applications et services, permettant l'accès à des informations temps réel et l'amélioration de l'intégration des personnes aveugles. Dans ce contexte, la thèse a contribué au développement d'un système d'information et de guidage destiné aux personnes aveugles dans les transports en commun. La thèse a porté sur deux aspects critiques de ce type de systèmes: la fiabilité de la transmission de données et la capacité à localiser et à guider l'utilisateur de manière robuste. Elle a d'autre part développé un environnement de simulation pour le prototypage et l'analyse du fonctionnement de l'application nomade ainsi que l'étude des aspects réseaux de communication mobile. Les travaux se sont appuyés sur les acquis des projets RAMPE et INFOMOVILLE / The development of communication and locating systems and the progress of mobile devices have made possible new applications and services, allowing access to real-time information and improving the integration of blind people. ln this context, the thesis has contributed to the development of an information and guidance system to be used by blind travellers in public transports. The work has focused on two critical aspects for this kind of systems: the reliability of data transmission and the ability of localizing and guiding the user in an efficient way. A simulation environment has also been developed that can be used for the prototyping and the analysis of the mobile application as well as for the study of communication over the wireless network. The thesis is based on the results of the RAMPE and INFOMOVILLE projects

AIM AND OBJECTIVES The investigation aimed to determine how the learning of the life sciences is facilitated (mediated) in special schools for blind learners and to establish how the lessons learnt from this experience could be implemented to the advantage of blind learners in the Senior Phase and Further Education and Training Band in inclusive Outcomes-based education settings. METHODOLOGY Educators and blind learners were interviewed through the use of the Qualitative Inquiry methodology as well as its techniques and strategies for data gathering. Analysis of the transcripts resulted in the development of themes/codes discussed in the research investigation. RESULTS Educators spent a good amount of time and effort with blind learners in the biology and life sciences classrooms. It appeared as if the pastoral role of the educator predominantly exceeded the teaching of biology and life sciences to these learners. Further, it became evident that the emphasis did not fall strongly enough on the achievement of the outcomes envisaged with the biology curriculum but more on the establishment of a caring and supportive classroom environment. CONCLUSIONS Biology and other life sciences subjects have much potential for the blind learners in South Africa but they are not offered at some of the schools or efficiently mediated due to educators’ reluctance, lack of knowledge and resources. Learning mediation strategies to make biology and life sciences more accessible to blind learners could be explored. / Thesis (PhD (Curriculum and Instructional Design and Development))--University of Pretoria, 2006. / Curriculum Studies / unrestricted

Ce travail se concentre sur une tâche de micro-navigation en plein air où le but est de naviguer vers une adresse de rue spécifiée en utilisant plusieurs modalités (par exemple, images, texte de scène et GPS). La tâche de micro-navigation extérieure s’avère etre un défi important pour de nombreuses personnes malvoyantes, ce que nous démontrons à travers des entretiens et des études de marché, et nous limitons notre définition des problèmes à leurs besoins. Nous expérimentons d’abord avec un monde en grille partiellement observable (Grid-Street et Grid City) contenant des maisons, des numéros de rue et des régions navigables. Ensuite, nous introduisons le Environnement de Trottoir pour la Navigation Visuelle (ETNV), qui contient des images panoramiques avec des boîtes englobantes pour les numéros de maison, les portes et les panneaux de nom de rue, et des formulations pour plusieurs tâches de navigation. Dans SEVN, nous formons un modèle de politique pour fusionner des observations multimodales sous la forme d’images à résolution variable, de texte visible et de données GPS simulées afin de naviguer vers une porte d’objectif. Nous entraînons ce modèle en utilisant l’algorithme d’apprentissage par renforcement, Proximal Policy Optimization (PPO). Nous espérons que cette thèse fournira une base pour d’autres recherches sur la création d’agents pouvant aider les membres de la communauté des gens malvoyantes à naviguer le monde. / This work focuses on an Outdoor Micro-Navigation (OMN) task in which the goal is to navigate to a specified street address using multiple modalities including images, scene-text, and GPS. This task is a significant challenge to many Blind and Visually Impaired (BVI) people, which we demonstrate through interviews and market research. To investigate the feasibility of solving this task with Deep Reinforcement Learning (DRL), we first introduce two partially observable grid-worlds, Grid-Street and Grid City, containing houses, street numbers, and navigable regions. In these environments, we train an agent to find specific houses using local observations under a variety of training procedures. We parameterize our agent with a neural network and train using reinforcement learning methods. Next, we introduce the Sidewalk Environment for Visual Navigation (SEVN), which contains panoramic images with labels for house numbers, doors, and street name signs, and formulations for several navigation tasks. In SEVN, we train another neural network model using Proximal Policy Optimization (PPO) to fuse multi-modal observations in the form of variable resolution images, visible text, and simulated GPS data, and to use this representation to navigate to goal doors. Our best model used all available modalities and was able to navigate to over 100 goals with an 85% success rate. We found that models with access to only a subset of these modalities performed significantly worse, supporting the need for a multi-modal approach to the OMN task. We hope that this thesis provides a foundation for further research into the creation of agents to assist members of the BVI community to safely navigate.

Indiana University-Purdue University Indianapolis (IUPUI) / To access interactive systems, blind and visually impaired users can leverage their auditory senses by using non-speech sounds. The current structure of non-speech sounds, however, is geared toward conveying user interface operations (e.g., opening a file) rather than large theme-based information (e.g., a history passage) and, thus, is ill-suited to signify the complex meanings of primary learning material (e.g., books and websites). In order to address this problem, this dissertation introduces audemes, a new category of non-speech sounds, whose semiotic structure and flexibility open new horizons for facilitating the education of blind and visually impaired students. An experiment with 21 students from the Indiana School for the Blind and Visually Impaired (ISBVI) supports the hypothesis that audemes increase the retention of theme-based information. By acting as memory catalysts, audemes can play an important role in enhancing the aural interaction and navigation in future sound-based user interfaces. For this dissertation, I designed an Acoustic EDutainment INterface (AEDIN) that integrates audemes as a way by which to vividly anticipate text-to-speech theme-based information and, thus, act as innovative aural covers. The results of two iterative usability evaluations with total of 20 blind and visually impaired participants showed that AEDIN is a highly usable and enjoyable acoustic interface. Yet, designing well-formed audemes remains an ad hoc process because audeme creators can only rely on their intuition to generate meaningful and memorable sounds. In order to address this problem, this dissertation presents three experiments, each with 10 blind and visually impaired participants. The goal was to examine the optimal combination of audeme attributes, which can be used to facilitate accurate recognitions of audeme meanings. This work led to the creation of seven basic guidelines that can be used to design well-formed audemes. An interactive application tool (ASCOLTA: Advanced Support and Creation-Oriented Library Tool for Audemes) operationalized these guidelines to support individuals without an audio background in designing well-formed audemes. An informal evaluation conducted with three teachers from the ISBVI, supports the hypothesis that ASCOLTA is a useful tool by which to facilitate the integration of audemes into the teaching environment.