617 research outputs found

    DESIGNING EYE TRACKING ALGORITHM FOR PARTNER-ASSISTED EYE SCANNING KEYBOARD FOR PHYSICALLY CHALLENGED PEOPLE

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    The proposed research work focuses on building a keyboard through designing an algorithm for eye movement detection using the partner-assisted scanning technique. The study covers all stages of gesture recognition, from data acquisition to eye detection and tracking, and finally classification. With the presence of many techniques to implement the gesture recognition stages, the main objective of this research work is implementing the simple and less expensive technique that produces the best possible results with a high level of accuracy. The results, finally, are compared with similar works done recently to prove the efficiency in implementation of the proposed algorithm. The system starts with the calibration phase, where a face detection algorithm is designed to detect the user‟s face by a trained support vector machine. Then, features are extracted, after which tracking of the eyes is possible by skin-colour segmentation. A couple of other operations were performed. The overall system is a keyboard that works by eye movement, through the partner-assisted scanning technique. A good level of accuracy was achieved, and a couple of alternative methods were implemented and compared. This keyboard adds to the research field, with a new and novel combination of techniques for eye detection and tracking. Also, the developed keyboard helps bridge the gap between physical paralysis and leading a normal life. This system can be used as comparison with other proposed algorithms for eye detection, and might be used as a proof for the efficiency of combining a number of different techniques into one algorithm. Also, it strongly supports the effectiveness of machine learning and appearance-based algorithms

    Engineering data compendium. Human perception and performance. User's guide

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    The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

    Panoramic, large-screen, 3-D flight display system design

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    The report documents and summarizes the results of the required evaluations specified in the SOW and the design specifications for the selected display system hardware. Also included are the proposed development plan and schedule as well as the estimated rough order of magnitude (ROM) cost to design, fabricate, and demonstrate a flyable prototype research flight display system. The thrust of the effort was development of a complete understanding of the user/system requirements for a panoramic, collimated, 3-D flyable avionic display system and the translation of the requirements into an acceptable system design for fabrication and demonstration of a prototype display in the early 1997 time frame. Eleven display system design concepts were presented to NASA LaRC during the program, one of which was down-selected to a preferred display system concept. A set of preliminary display requirements was formulated. The state of the art in image source technology, 3-D methods, collimation methods, and interaction methods for a panoramic, 3-D flight display system were reviewed in depth and evaluated. Display technology improvements and risk reductions associated with maturity of the technologies for the preferred display system design concept were identified

    Head tracking two-image 3D television displays

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    The research covered in this thesis encompasses the design of novel 3D displays, a consideration of 3D television requirements and a survey of autostereoscopic methods is also presented. The principle of operation of simple 3D display prototypes is described, and design of the components of optical systems is considered. A description of an appropriate non-contact infrared head tracking method suitable for use with 3D television displays is also included. The thesis describes how the operating principle of the displays is based upon a twoimage system comprising a pair of images presented to the appropriate viewers' eyes. This is achieved by means of novel steering optics positioned behind a direct view liquid crystal display (LCD) that is controlled by a head position tracker. Within the work, two separate prototypes are described, both of which provide 3D to a single viewer who has limited movement. The thesis goes on to describe how these prototypes can be developed into a multiple-viewer display that is suitable for television use. A consideration of 3D television requirements is documented showing that glassesfree viewing (autostereoscopic), freedom of viewer movement and practical designs are important factors for 3D television displays. The displays are novel in design in several important aspects that comply with the requirements for 3D television. Firstly they do not require viewers to wear special glasses, secondly the displays allow viewers to move freely when viewing and finally the design of the displays is practical with a housing size similar to modem television sets and a cost that is not excessive. Surveys of other autostereoscopic methods included within the work suggest that no contemporary 3D display offers all of these important factors

    Vision Science and Technology at NASA: Results of a Workshop

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    A broad review is given of vision science and technology within NASA. The subject is defined and its applications in both NASA and the nation at large are noted. A survey of current NASA efforts is given, noting strengths and weaknesses of the NASA program

    Change blindness: eradication of gestalt strategies

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    Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

    Visual Perception and Cognition in Image-Guided Intervention

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    Surgical image visualization and interaction systems can dramatically affect the efficacy and efficiency of surgical training, planning, and interventions. This is even more profound in the case of minimally-invasive surgery where restricted access to the operative field in conjunction with limited field of view necessitate a visualization medium to provide patient-specific information at any given moment. Unfortunately, little research has been devoted to studying human factors associated with medical image displays and the need for a robust, intuitive visualization and interaction interfaces has remained largely unfulfilled to this day. Failure to engineer efficient medical solutions and design intuitive visualization interfaces is argued to be one of the major barriers to the meaningful transfer of innovative technology to the operating room. This thesis was, therefore, motivated by the need to study various cognitive and perceptual aspects of human factors in surgical image visualization systems, to increase the efficiency and effectiveness of medical interfaces, and ultimately to improve patient outcomes. To this end, we chose four different minimally-invasive interventions in the realm of surgical training, planning, training for planning, and navigation: The first chapter involves the use of stereoendoscopes to reduce morbidity in endoscopic third ventriculostomy. The results of this study suggest that, compared with conventional endoscopes, the detection of the basilar artery on the surface of the third ventricle can be facilitated with the use of stereoendoscopes, increasing the safety of targeting in third ventriculostomy procedures. In the second chapter, a contour enhancement technique is described to improve preoperative planning of arteriovenous malformation interventions. The proposed method, particularly when combined with stereopsis, is shown to increase the speed and accuracy of understanding the spatial relationship between vascular structures. In the third chapter, an augmented-reality system is proposed to facilitate the training of planning brain tumour resection. The results of our user study indicate that the proposed system improves subjects\u27 performance, particularly novices\u27, in formulating the optimal point of entry and surgical path independent of the sensorimotor tasks performed. In the last chapter, the role of fully-immersive simulation environments on the surgeons\u27 non-technical skills to perform vertebroplasty procedure is investigated. Our results suggest that while training surgeons may increase their technical skills, the introduction of crisis scenarios significantly disturbs the performance, emphasizing the need of realistic simulation environments as part of training curriculum

    Use of Depth Perception for the Improved Understanding of Hydrographic Data

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    This thesis has reviewed how increased depth perception can be used to increase the understanding of hydrographic data First visual cues and various visual displays and techniques were investigated. From this investigation 3D stereoscopic techniques prove to be superior in improving the depth perception and understanding of spatially related data and a further investigation on current 3D stereoscopic visualisation techniques was carried out. After reviewing how hydrographic data is currently visualised it was decided that the chromo stereoscopic visualisation technique is preferred to be used for further research on selected hydrographic data models. A novel chromo stereoscopic application was developed and the results from the evaluation on selected hydrographic data models clearly show an improved depth perception and understanding of the data models

    Ubiquitous computing and natural interfaces for environmental information

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    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de Mestre em Engenharia do Ambiente, perfil Gestão e Sistemas AmbientaisThe next computing revolution‘s objective is to embed every street, building, room and object with computational power. Ubiquitous computing (ubicomp) will allow every object to receive and transmit information, sense its surroundings and act accordingly, be located from anywhere in the world, connect every person. Everyone will have the possibility to access information, despite their age, computer knowledge, literacy or physical impairment. It will impact the world in a profound way, empowering mankind, improving the environment, but will also create new challenges that our society, economy, health and global environment will have to overcome. Negative impacts have to be identified and dealt with in advance. Despite these concerns, environmental studies have been mostly absent from discussions on the new paradigm. This thesis seeks to examine ubiquitous computing, its technological emergence, raise awareness towards future impacts and explore the design of new interfaces and rich interaction modes. Environmental information is approached as an area which may greatly benefit from ubicomp as a way to gather, treat and disseminate it, simultaneously complying with the Aarhus convention. In an educational context, new media are poised to revolutionize the way we perceive, learn and interact with environmental information. cUbiq is presented as a natural interface to access that information
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