Thesis (M.S.)--University of Florida, 2001. / Title from first page of PDF file. Document formatted into pages; contains vii, 45 p.; also contains graphics. Vita. Includes bibliographical references (p. 43-44).

The results presented in this dissertation concern two different types of tomographic imaging. The first part of the dissertation is devoted to the time reversal method for approximate reconstruction of images in thermoacoustic tomography. A thorough numerical study of the method is presented. Error estimates of the time reversal approximation are provided. In the second part of the dissertation a type of emission tomography, called Compton camera imaging is considered. The mathematical problem arising in Compton camera imaging is the inversion of the cone transform. We present three methods for inversion of this transform in two dimensions. Numerical examples of reconstructions by these methods are also provided. Lastly, we turn to a problem of significance in homeland security, namely the detection of geometrically small, low emission sources in the presence of a large background radiation. We consider the use of Compton type detectors for this purpose and describe an efficient method for detection of such sources. Numerical examples demonstrating this method are also provided.

The study and application of machine vision in early years mostly focus on a single camera. However, the trend of research on multiple cameras has been developed recently. Due to highly complicated correlation among multiple images, the arrangement of multiple cameras was restricted to the encirclement layout for acquiring more than one views of a target object. Furthermore, it has been well known that the special architecture of insect compound eyes contributes outstanding capability for precise and efficient observation of moving objects. If this technique can be transferred to the domain of engineering applications, significant improvement on visual tracking of moving objects will be greatly expected. This thesis builds a visual servo system with trinocular cameras by mimicking the configuration of compound eye of insects for tracking an object moving in 2D space. The arrangement of the trinocular cameras is divergent, and this system can function properly without the information of distance between the object and the cameras.

Thesis (M.S.)--University of Florida, 2001. / Title from first page of PDF file. Document formatted into pages; contains vii, 45 p.; also contains graphics. Vita. Includes bibliographical references (p. 43-44).

Thesis (Ph. D.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 167-179).

No description available.

This study analyses certain aspects of the relationship between culture and technology by using the example of the 35mm still photographic camera. Methodologically, the study integrates two perspectives in communication theory, namely diffusion of innovation and cultural studies. The study consists of five segments. First, the need for technological innovation is defined in terms of developing social formations. Secondly, the history of photographic research and development is traced in terms of various models of industrial development, and in terms of the horizontal and vertical integration of manufacturing. The commercialization of the camera is treated in relation to the history of markets, and their disturbances by war and other political developments. Next, the study provides an analysis of specialty magazine advertising as it relates to the 35mm camera. Finally, the adoption and utilization of this new technology are discussed in terms of the competing interests of various social formations in modern society.

It is commonly known that stereopsis is the primary way for humans to perceive depth. Although, with one eye, we can still interact very well with our environment and do very highly skillful tasks by using other visual cues such as occlusion and motion, the resultant e ect of the absence of stereopsis is that the relative depth information between objects is essentially lost (Frisby,1979). While humans fuse the images seen by the left and right eyes in a seemingly easy way, the major problem - the correspondence of features - that needs to be solved in all binocular stereo systems of machine vision is not trivial. In this thesis, line segments and corners are chosen to be the features to be matched because they typically occur at object boundaries, surface discontinuities, and across surface markings. Polygonal regions are also selected since they are known to be well-configured and are, very often, associated with salient structures in the image. The use of these high level features, although helping to diminish matching ambiguities, does not completely resolve the matching problem when the scene contains repetitive structures. The spatial relationships between the feature matching pairs enforced in the stereo matching process, as proposed in this thesis, are found to provide even stronger support for correct feature matching pairs and, as a result, incorrect matching pairs can be largely eliminated. Getting global and salient 3D structures has been an important prerequisite for environmental modelling and understanding. While research on postprocessing the 3D information obtained from stereo has been attempted (Ayache and Faugeras, 1991), the strategy presented in this thesis for retrieving salient 3D descriptions is propagating the prominent information extracted from the 2D images to the 3D scene. Thus, the matching of two prominent 2D polygonal regions yields a prominent 3D region, and the inter-relation between two 2D region matching pairs is passed on and taken as a relationship between two 3D regions. Humans, when observing and interacting with the environment do not confine themselves to the observation and then the analysis of a single image. Similarly stereopsis can be vastly improved with the introduction of additional stereo image pairs. Eye, head, and body movements provide essential mobility for an active change of viewpoints, the disocclusion of occluded objects, the avoidance of obstacles, and the performance of any necessary tasks on hand. This thesis presents a mobile stereo vision system that has its eye movements provided by a binocular head support and stepper motors, and its body movements provided by a mobile platform, the Labmate. With a viewer centred coordinate system proposed in this thesis the computation of the 3D information observed at each individual viewpoint, the merging of the 3D in formation at consecutive viewpoints for environmental reconstruction, and strategies for movement control are discussed in detail.

Thesis (M.S.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references (leaves 88-90). Also available on the World Wide Web.

Road traffic accidents continue to be a public health problem and are a global issue due to the huge financial burden they place on families and society as a whole. Speed has been identified as a major contributor to the severity of traffic accidents and there is the need for better speed management if road traffic accidents are to be reduced. Over the years various measures have been implemented to manage vehicle speeds. The use of speed cameras and vehicle activated signs in recent times has contributed to the reduction of vehicle speeds to various extents. Speed cameras use punitive measures whereas vehicle activated signs do not so their use depends on various factors. Engineers, planners and decision makers responsible for determining the best place to mount a speed camera or vehicle activated sign along a road have based their decision on experience, site characteristics and available guidelines (Department for Transport, 2007; Department for Transport, 2006; Department for Transport, 2003). These decisions can be subjective and indications are that a more formal and directed approach aimed at bringing these available guidelines together in a model will be beneficial in making the right decision as to where to place a speed camera or vehicle activated sign is to be made. The use of optimisation techniques have been applied in other areas of research but this has been clearly absent in the Transport Safety sector. This research aims to contribute to speed reduction by developing a model to help decision makers determine the optimum location for a speed control device. In order to achieve this, the first study involved the development of an Empirical Bayes Negative Binomial regression accident prediction model to predict the number of fatal and serious accidents combined and the number of slight accidents. The accident prediction model that was used explored the effect of certain geometric and traffic characteristics on the effect of the severity of road traffic accident numbers on selected A-roads within the Nottinghamshire and Leicestershire regions of United Kingdom. On A-roads some model variables (n=10) were found to be statistically significant for slight accidents and (n=6) for fatal and serious accidents. The next study used the accident prediction model developed in two optimisation techniques to help predict the optimal location for speed cameras or vehicle activated signs. Pattern Search and Genetic Algorithms were the two main types of optimisation techniques utilised in this thesis. The results show that the two methods did produce similar results in some instances but different in others. Optimised results were compared to some existing sites with speed cameras some of the results obtained from the optimisation techniques used were within proximity of about 160m. A validation method was applied to the genetic algorithm and pattern search optimisation methods. The pattern search method was found to be more consistent than the genetic algorithm method. Genetic algorithm results produced slightly different results at validation in comparison with the initial results. T-test results show a significant difference in the function values for the validated genetic algorithm (M= 607649.34, SD= 1055520.75) and the validated pattern search function values (M= 2.06, SD= 1.17) under the condition t (79) = 5.15, p=0.000. There is a role that optimisation techniques can play in helping to determine the optimum location for a speed camera or vehicle activated sign based on a set of objectives and specified constraints. The research findings as a whole show that speed cameras and vehicle activated signs are an effective speed management tool. Their deployment however needs to be carefully considered by engineers, planners and decision makers so as to achieve the required level of effectiveness. The use of optimisation techniques which has been generally absent in the Transport Safety sector has been shown in this thesis to have the potential to contribute to improve speed management. There is however no doubt that this research will stimulate interest in this rather new but high potential area of Transport Safety.