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Monocular Obstacle Detection for Moving VehiclesLalonde, Jeffrey R. 18 January 2012 (has links)
This thesis presents a 3D reconstruction approach to the detection of static obstacles from a single rear view parking camera. Corner features are tracked to estimate the vehicle’s motion and to perform multiview triangulation in order to reconstruct the scene. We model the camera motion as planar motion and use the knowledge of the camera pose to efficiently solve motion parameters. Based on the observed motion, we selected snapshots from which the scene is reconstructed. These snapshots guarantee a sufficient baseline between the images and result in more robust scene modeling. Multiview triangulation of a feature is performed only if the feature obeys the epipolar constraint. Triangulated features are semantically labelled according to their 3D location. Obstacle features are spatially clustered to reduce false detections. Finally, the distance to the nearest obstacle cluster is reported to the driver.
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Interpretación radical y escepticismo.Coll Mármol, Jesús 17 July 2006 (has links)
En este trabajo se examina si de las consideraciones que Donald Davidson ha hecho del caso de la interpretación radical se sigue algo así como una refutación del escepticismo. Se argumenta que tal conclusión no se sigue de las posiciones acerca de la naturaleza del pensamiento y del lenguaje mantenidas por este filósofo americano, ni siquiera con la ayuda del así llamado argumento del intérprete omnisciente. También se rechaza la idea de que concebir su argumentación como un argumento trascendental modesto proporcione mejores resultados antiescépticos. Finalmente se defiende que el mejor modo de articular su posición es como un diagnóstico teórico del escepticismo al estilo del defendido por Michael Williams en su libro Unnatural Doubts. Desde este punto de vista lo que la filosofía davidsoniana haría sería reprochar al escéptico su adhesión al representacionismo y mostrar una alternativa al mismo que explique la posibilidad del pensamiento y del lenguaje. Concebida así la filosofía davidsoniana no constituiría una victoria definitiva ante el escepticismo, sino que más bien mostraría que su posición no es obligatoria y, al menos, garantizaría una presunción de inocencia para nuestras creencias ante el reto del escéptico global. / This work examines whether it follows a refutation of scepticism from Donald Davidson's work on radical interpretation. It is argued that such a conclusion does not follow from Donald Davidson's views on thought and language, not even with the help of the so called omniscient interpreter argument. This work also rejects that such views on language and thought lead to a better result against scepticism when interpreted as a modest transcendental argument. Finally it is claimed that the best way of articulating Davidson's antisceptical strategy is as a theoretical diagnosis of scepticism in a similar vein as Michael Williams has developed in his book Unnatural Doubts. From this point of view what Davidson's philosophy would do is, on the one hand, to reproach the sceptic his adherence to representationism and, on the other hand, to defend an alternative to this philosophical view that explains how thought and language are possible. Conceived of in this way, Davidson's philosophy would not constitute a definitive victory against scepticism. However it would show that scepticism is not compulsory and, at the very least, it would guarantee a presumption of innocence for our beliefs when they face the sceptical threat.
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Laser Music System : Implemented using lasers, infrared sensors, photocells and a Arduino MicrocontrollerWoodruff, Astra, Görmez, Burak January 2012 (has links)
A Laser Music System has been created, that combines a laser and light sensor system with an infrared distance sensing system that detects the position of a user’s hand when it intersects one or more of the individual laser beam. The laser beams, which are made visible by a small amount of smoke in a dark room, provide visual guidance to the user to reduce the difficulty of using a non-contact instrument as well as enhancing an appealing optical effect for the user. The system uses a number of Sharp distance sensors to map the position of the user’s hand to a variable like pitch. The user should move their hand to different heights to achieve a desired pitch. The laser beam should be broken to trigger the desired note.
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Surface reconstruction using variational interpolationJoseph Lawrence, Maryruth Pradeepa 24 November 2005 (has links)
Surface reconstruction of anatomical structures is an integral part of medical modeling. Contour information is extracted from serial cross-sections of tissue data and is stored as "slice" files. Although there are several reasonably efficient triangulation algorithms that reconstruct surfaces from slice data, the models generated from them have a jagged or faceted appearance due to the large inter-slice distance created by the sectioning process. Moreover, inconsistencies in user input aggravate the problem. So, we created a method that reduces inter-slice distance, as well as ignores the inconsistencies in the user input. Our method called the piecewise weighted implicit functions, is based on the approach of weighting smaller implicit functions. It takes only a few slices at a time to construct the implicit function. This method is based on a technique called variational interpolation. <p> Other approaches based on variational interpolation have the disadvantage of becoming unstable when the model is quite large with more than a few thousand constraint points. Furthermore, tracing the intermediate contours becomes expensive for large models. Even though some fast fitting methods handle such instability problems, there is no apparent improvement in contour tracing time, because, the value of each data point on the contour boundary is evaluated using a single large implicit function that essentially uses all constraint points. Our method handles both these problems using a sliding window approach. As our method uses only a local domain to construct each implicit function, it achieves a considerable run-time saving over the other methods. The resulting software produces interpolated models from large data sets in a few minutes on an ordinary desktop computer.
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The localized Delaunay triangulation and ad-hoc routing in heterogeneous environmentsWatson, Mark Duncan 03 January 2006 (has links)
Ad-Hoc Wireless routing has become an important area of research in the last few years due to the massive increase in wireless devices. Computational Geometry is relevant in attempts to build stable, low power routing schemes. It is only recently, however, that models have been expanded to consider devices with a non-uniform broadcast range, and few properties are known. In particular, we find, via both theoretical and experimental methods, extremal properties for the Localized Delaunay Triangulation over the Mutual Inclusion Graph. We also provide a distributed, sub-quadratic algorithm for the generation of the structure.
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Empowerment i fältarbete - Boendestödsteamet i VästeråsLarsson, Caroline, Mayes, Diana January 2008 (has links)
The aim of this study was to observe the housing support team (boendestödssteamet) in Västerås City in its visiting work and how they empowered clients. Tenants are visited by social workers, in its visiting works, when the habitants have rental charge debts. Participating observations is common in case studies, but also in fieldwork which was the foundation in our study. Our method of collecting data consisted of a triangulation; unstructured interviews with social workers, participating observations and a following up with a questionnaire. We took part in participating observations of social workers whilst visiting tenants with rental charge debts. The social services in Västerås City are getting 120-125 reports concerning rental debts from the landlords every month. We visited 46 tenants and it resulted in 23 of them paying their rental debts. All of the tenants have not paid their rental debts. We have seen how em-powering social workers activity is. Empowerment has been seen in individuals while regain-ing their own power, but also in the community when taking control over their problems with too large rental debts. Empowerment becomes a social work tool, in their visiting work, in helping tenants.
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Laser Triangulation Using Spacetime AnalysisBenderius, Björn January 2007 (has links)
<p>In this thesis spacetime analysis is applied to laser triangulation in an attempt to eliminate certain artifacts caused mainly by reflectance variations of the surface being measured. It is shown that spacetime analysis do eliminate these artifacts almost completely, it is also shown that the shape of the laser beam used no longer is critical thanks to the spacetime analysis, and that in some cases the laser probably even could be exchanged for a non-coherent light source. Furthermore experiments of running the derived algorithm on a GPU (Graphics Processing Unit) are conducted with very promising results.</p><p>The thesis starts by deriving the theory needed for doing spacetime analysis in a laser triangulation setup taking perspective distortions into account, then several experiments evaluating the method is conducted.</p>
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Visualisering och beräkning av hudkapillärer / Skin Capillary Ensemble Visualisation and ComputationFredriksson, Ingemar January 2004 (has links)
<p>The aim of this thesis was to develop an objective and automatic method for identifying capillaries in microscope images of the skin. Furthermore, statistical data about the identified capillaries and the capillary distribution should be computed and stored in a database. The method was implemented using the platform independent programming language Java. An analysis of microscope improvement using various polarization filter setups and wavelength filtershas also been performed, as well as a pilot study of the effect of applying a local anaesthetic cream on the skin. The method is developed and aimed at research on various pathological skin conditions affecting the capillary distribution. Hypertension, diabetes, inflammation, ischemia, connective tissue disease, and erythromelalgia are all examples of diseases or pathological conditions which are supposed to affect the distribution of the skin capillaries.</p>
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A calibration method for laser-triangulating 3D cameras / En kalibreringsmetod för lasertriangulerande 3D-kamerorAndersson, Robert January 2008 (has links)
<p>A laser-triangulating range camera uses a laser plane to light an object. If the position of the laser relative to the camera as well as certrain properties of the camera is known, it is possible to calculate the coordinates for all points along the profile of the object. If either the object or the camera and laser has a known motion, it is possible to combine several measurements to get a three-dimensional view of the object.</p><p>Camera calibration is the process of finding the properties of the camera and enough information about the setup so that the desired coordinates can be calculated. Several methods for camera calibration exist, but this thesis proposes a new method that has the advantages that the objects needed are relatively inexpensive and that only objects in the laser plane need to be observed. Each part of the method is given a thorough description. Several mathematical derivations have also been added as appendices for completeness.</p><p>The proposed method is tested using both synthetic and real data. The results show that the method is suitable even when high accuracy is needed. A few suggestions are also made about how the method can be improved further.</p>
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The experience of falling of older people with dementia and their carersMcIntyre, Anne Elizabeth January 2012 (has links)
Falling by older people is of significant global concern as the population ages, because of subsequent injury, disability, admission to long-term care and mortality. Older people experiencing dementia are twice as likely to fall with more severe consequences. Unsurprisingly, carer-burden increases when a care-recipient falls. Older people are rarely asked about their falls experiences and those with dementia less so. The studies presented in this thesis explore the experiences of falling of older people with dementia and memory problems, and their carers. The studies were informed by contextualism and the primary study used interpretative phenomenological analysis to explore the experiences of nine older people with dementia and their 10 carers, using one-to-one and joint interviews, and three focus groups with nine older people experiencing memory problems and 12 carers from a branch of the Alzheimer’s society. Analysis of the data considered the falls experience itself and the perceived consequences of falls within two higher level themes: ‘Falling as a malevolent force’ as two themes - ‘Going back to the experience’, ‘Reactions, responses and coming to terms with events’, and ‘Falling as the manifestation of dementia’ as two themes - ‘Self, identity and falling’, ‘The caring relationship’. The secondary study elaborated upon primary study data using an inductive interpretative approach unaligned to any tradition. Older people recently diagnosed with dementia and carers from another Alzheimer’s Society branch participated in two focus groups. Participants discussed stimulus cards with quotations from primary study participants. Thematic analysis suggested four major themes: Making sense of falls, The personal and social significance of falling, Falling, self and identity and Struggling to care. The findings demonstrate how falling and dementia are enmeshed and embodied experiences for participants. Spouse-carers’ discussion of their own falls emphasise the need for joint assessment and intervention to reduce carerburden and preserve couplehood.
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