553 research outputs found

    Schematisation in Hard-copy Tactile Orientation Maps

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    This dissertation investigates schematisation of computer-generated tactile orientation maps that support mediation of spatial knowledge of unknown urban environments. Computergenerated tactile orientation maps are designed to provide the blind with an overall impression of their surroundings. Their details are displayed by means of elevated features that are created by embossers and can be distinguished by touch. The initial observation of this dissertation states that only very little information is actually transported through tactile maps owing to the coarse resolution of tactual senses and the cognitive effort involved in the serial exploration of tactile maps. However, the differences between computer-generated, embossed tactile maps and manufactured, deep-drawn tactile maps are significant. Therefore the possibilities and confines of communicating information through tactile maps produced with embossers is a primary area of research. This dissertation has been able to demonstrate that the quality of embossed prints is an almost equal alternative to traditionally manufactured deep-drawn maps. Their great advantage is fast and individual production and (apart from the initial procurement costs for the printer)low price, accessibility and easy understanding without the need of prior time-consuming training. Simplification of tactile maps is essential, even more so than in other maps. It can be achieved by selecting a limited number from all map elements available. Qualitative simplification through schematisation may present an additional option to simplification through quantitative selection. In this context schematisation is understood as cognitively motivated simplification of geometry and synchronised maintenance of topology. Rather than further reducing the number of displayed objects, the investigation concentrates on how the presentation of different forms of streets (natural vs. straightened) and junctions (natural vs. prototypical) affects the transfer of knowledge. In a second area of research, a thesis establishes that qualitative simplification of tactile orientation maps through schematisation can enhance their usability and make them easier to understand than maps that have not been schematised. The dissertation shows that simplifying street forms and limiting them to prototypical junctions does not only accelerate map exploration but also has a beneficial influence on retention performance. The majority of participants that took part in the investigation selected a combination of both as their preferred display option. Tactile maps that have to be tediously explored through touch, uncovering every detail, complicate attaining a first impression or an overall perception. A third area of research is examined, establishing which means could facilitate map readersâ options to discover certain objects on the map quickly and without possessing a complete overview. Three types of aids are examined: guiding lines leading from the frame of the map to the object, position indicators represented by position markers at the frame of the map and coordinate specifications found within a grid on the map. The dissertation shows that all three varieties can be realised by embossers. Although a guiding line proves to be fast in size A4 tactile maps containing only one target object and few distracting objects, it also impedes further exploration of the map (similar to the grid). In the following, advantages and drawbacks of the various aids in this and other applications are discussed. In conclusion the dissertation elaborates on the linking points of all three examinations. They connect and it is argued that cognitively motivated simplification should be a principle of construction for embossed tactile orientation maps in order to support their use and comprehension. A summary establishes the recommendations that result from this dissertation regarding construction of tactile orientation maps considering the limitations through embosser constraints. Then I deliberate how to adapt schematisation of other maps contingent to intended function, previous knowledge of the map reader, and the relation between the time in which knowledge is acquired and the time it is employed. Closing the dissertation, I provide an insight into its confines and deductions and finish with a prospective view to possible transfers of the findings to other applications, e.g. multimedia or interactive maps on pin-matrix displays and devices

    Library Facilities and Services for Differently Abled Students in Universities of Karnataka: A Study

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    Purpose – In Karnataka, there are considerable number of differently abled persons, who are studying in various educational institutions. It has been observed that some of the educational institutions provided with suitable access facilities in Libraries to the disabled, but majority of them are devoid of this facility. In this article, an attempt has been made to study on the facilities being provided to the disabled users in some of the University Libraries of Karnataka. The facilities being provided are briefed under 3 major categories – (1) Access to resources, (2) Physical access to library building, and (3) Services and communications. Design/Methodology/Approach – Questionnaire method has been adopted to collect data from identified 21 Universities in India. Responses received from the Libraries have been analysed and presented. Findings – The findings are presented under above mentioned 3 major categories in the body of the article. Originality/Value – The present work is original in nature. The study will be useful to the disabled to understand on the facilities available for them in the selected Universities of Karnataka

    “AccessBIM” - A Model of Environmental Characteristics for Vision Impaired Indoor Navigation and Way Finding

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    The complexity of modern indoor environments has made navigation difficult for individuals with vision impairment. Hence, this thesis presents the AccessBIM framework, which is an optimized database that’s facilitates generation of a real-time floor plan with path determination. The AccessBIM framework has the potential to play an integral role in improving the independence and quality of life for people with vision impairment whilst also decreasing the cost to the community related to caretakers

    Aerospace Medicine and Biology: A continuing bibliography with indexes (supplement 314)

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    This bibliography lists 139 reports, articles, and other documents introduced into the NASA scientific and technical information system in August, 1988

    Using Sonic Enhancement to Augment Non-Visual Tabular Navigation

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    More information is now readily available to computer users than at any time in human history; however, much of this information is often inaccessible to people with blindness or low-vision, for whom information must be presented non-visually. Currently, screen readers are able to verbalize on-screen text using text-to-speech (TTS) synthesis; however, much of this vocalization is inadequate for browsing the Internet. An auditory interface that incorporates auditory-spatial orientation was created and tested. For information that can be structured as a two-dimensional table, links can be semantically grouped as cells in a row within an auditory table, which provides a consistent structure for auditory navigation. An auditory display prototype was tested. Sixteen legally blind subjects participated in this research study. Results demonstrated that stereo panning was an effective technique for audio-spatially orienting non-visual navigation in a five-row, six-column HTML table as compared to a centered, stationary synthesized voice. These results were based on measuring the time- to-target (TTT), or the amount of time elapsed from the first prompting to the selection of each tabular link. Preliminary analysis of the TTT values recorded during the experiment showed that the populations did not conform to the ANOVA requirements of normality and equality of variances. Therefore, the data were transformed using the natural logarithm. The repeated-measures two-factor ANOVA results show that the logarithmically-transformed TTTs were significantly affected by the tonal variation method, F(1,15) = 6.194, p= 0.025. Similarly, the results show that the logarithmically transformed TTTs were marginally affected by the stereo spatialization method, F(1,15) = 4.240, p=0.057. The results show that the logarithmically transformed TTTs were not significantly affected by the interaction of both methods, F(1,15) = 1.381, p=0.258. These results suggest that some confusion may be caused in the subject when employing both of these methods simultaneously. The significant effect of tonal variation indicates that the effect is actually increasing the average TTT. In other words, the presence of preceding tones increases task completion time on average. The marginally-significant effect of stereo spatialization decreases the average log(TTT) from 2.405 to 2.264

    Wayfinding across ocean and tundra: what traditional cultures teach us about navigation

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    Research on human navigation by psychologists and neuroscientists has come mainly from a limited range of environments and participants inhabiting western countries. By contrast, numerous anthropological accounts illustrate the diverse ways in which cultures adapt to their surrounding environment to navigate. Here, we provide an overview of these studies and relate them to cognitive science research. The diversity of cues in traditional navigation is much higher and multimodal compared with navigation experiments in the laboratory. It typically involves an integrated system of methods, drawing on a detailed understanding of the environmental cues, specific tools, and forms part of a broader cultural system. We highlight recent methodological developments for measuring navigation skill and modelling behaviour that will aid future research into how culture and environment shape human navigation

    Taux : a system for evaluating sound feedback in navigational tasks

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    This thesis presents the design and development of an evaluation system for generating audio displays that provide feedback to persons performing navigation tasks. It first develops the need for such a system by describing existing wayfinding solutions, investigating new electronic location-based methods that have the potential of changing these solutions and examining research conducted on relevant audio information representation techniques. An evaluation system that supports the manipulation of two basic classes of audio display is then described. Based on prior work on wayfinding with audio display, research questions are developed that investigate the viability of different audio displays. These are used to generate hypotheses and develop an experiment which evaluates four variations of audio display for wayfinding. Questions are also formulated that evaluate a baseline condition that utilizes visual feedback. An experiment which tests these hypotheses on sighted users is then described. Results from the experiment suggest that spatial audio combined with spoken hints is the best approach of the approaches comparing spatial audio. The test experiment results also suggest that muting a varying audio signal when a subject is on course did not improve performance. The system and method are then refined. A second experiment is conducted with improved displays and an improved experiment methodology. After adding blindfolds for sighted subjects and increasing the difficulty of navigation tasks by reducing the arrival radius, similar comparisons were observed. Overall, the two experiments demonstrate the viability of the prototyping tool for testing and refining multiple different audio display combinations for navigational tasks. The detailed contributions of this work and future research opportunities conclude this thesis

    The Speed, Precision and Accuracy of Human Multisensory Perception following Changes to the Visual Sense

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    Human adults can combine information from multiple senses to improve their perceptual judgments. Visual and multisensory experience plays an important role in the development of multisensory integration, however it is unclear to what extent changes in vision impact multisensory processing later in life. In particular, it is not known whether adults account for changes to the relative reliability of their senses, following sensory loss, treatment or training. Using psychophysical methods, this thesis studied the multisensory processing of individuals experiencing changes to the visual sense. Chapters 2 and 3 assessed whether patients implanted with a retinal prosthesis (having been blinded by a retinal degenerative disease) could use this new visual signal with non-visual information to improve their speed or precision on multisensory tasks. Due to large differences between the reliabilities of the visual and non-visual cues, patients were not always able to benefit from the new visual signal. Chapter 4 assessed whether patients with degenerative visual loss adjust the weight given to visual and non-visual cues during audio-visual localization as their relative reliabilities change. Although some patients adjusted their reliance on vision across the visual field in line with predictions based on cue relative reliability, others - patients with visual loss limited to their central visual field only - did not. Chapter 5 assessed whether training with either more reliable or less reliable visual feedback could enable normally sighted adults to overcome an auditory localization bias. Findings suggest that visual information, irrespective of reliability, can be used to overcome at least some non-visual biases. In summary, this thesis documents multisensory changes following changes to the visual sense. The results improve our understanding of adult multisensory plasticity and have implications for successful treatments and rehabilitation following sensory loss
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