Typescript (Photocopy) / Bibliography: leaves 243-284 / 284 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--Dept. of Surgery, University of Adelaide, Dept. of Surgery, 1992

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 143-150).

Visual interpretation of noisy images is not an easy problem. This is certainly apparent with ultrasound images. Due to the noise inherent in the images, it is often the case that discrepancies as to location of object boundaries and detection of different tissues arise even among highly trained physicians. The relatively low cost and short image acquisition time, however, make ultrasound an attractive imaging modality. Currently, diagnostic evaluation of ultrasound images is performed on two-dimensional (2D) cross-sections of the object of interest. No depth information is available and there is no way of viewing the outer surface of the object. The only way for a physician to visualise the entire object is by mentally reconstructing the object based on a series of a 2D images as well as prior expectations of the morphology of the object. In the case of abnormal or diseased growth, the physician's expectations often do not correspond to the actual morphology of the object. However, the use of three-dimensional (3D) data acquisition and visualisation may be used to overcome these problems. The present work addresses a number of difficulties in processing 3D ultrasound data. This includes special treatment of the volumetric ultrasound data obtained from a 3D probe, determination of 3D features of the different tissue types present in the ultrasound data and identification and localisation of objects (segmentation) in the volumetric ultrasound data. Experimental results obtained from synthesised and real ultrasound data demonstrate that the present work contributes significantly to the use of ultrasound imaging as a diagnostic tool. As well, the present work can be applied to different imaging modalities or different applications areas and is thus beneficial to the area of biomedical image processing, in general.

In the last decade, a significant amount of research has been performed to characterize the microstructure of unsheared and sheared triaxial sand specimens to advance the understanding of the engineering behavior of soils. However, most of the research has been limited to two-dimensional (2-D) image analysis of section planes that resulted in loss of information regarding the skeleton of the soil (pore structure) and other attributes of the three-dimensional (3-D) microstructure. In this research, the 3-D microstructures of triaxial test specimens were, for the first time, characterized. A serial sectioning technique was developed for obtaining 3-D microstructure from 2-D sections of triaxial test specimens. The mosaic technique was used to get high-resolution large field of view images. Various 3-D characterization parameters were used to study the microstructures of the specimens. To study the preparation method induced variation in soil microstructure, two specimens prepared with air pluviation and moist tamping methods were preserved with epoxy impregnation. A coupon was cut from the center of each specimen, and following a serial sectioning and image capture process, the 3-D structure was reconstructed. To study the evolution of structure during shearing tests, two additional specimens prepared to the same initial conditions with the same methods were subjected to axial compression loading under constant confining pressure up to an axial strain level of 14%. After shearing, the structure of these specimens were also preserved and analyzed following the same procedures as the unsheared specimens. The evolution of the pore structures was investigated accordingly. It was found that generally, moist tamped specimens were initially less uniform but had a more isotropic structure than air pluviated specimens. The standard deviations of 2-D local void ratio and 3-D pore size in dilated regions of sheared air pluviated and moist-tamped specimens were found to be smaller than those of as-consolidated specimens at a given void ratio. Tortuosity decreased with increasing pore size. It was also evident that the soil structures evolved differently depending on the initial structure. Comparison between 2-D and 3-D results indicated that it is not sufficient to use 2-D section information for characterizing some microstructural features.

The focus of this research was to develop interconnect-centric physical design tools for 3D technologies. A new routing model for the SOP structure was developed which incorporated the 3D structure and formalized the resource structure that facilitated the development of the global routing tool. The challenge of this work was to intelligently convert the 3D SOP routing problem into a set of 2D problems which could be solved efficiently. On the lines of MCM, the global routing problem was divided into a number of phases namely, coarse pin distribution, net distribution, detailed pin distribution, topology generation, layer assignment, channel assignment and local routing. The novelty in this paradigm is due to the feed-through vias needed by the nets which traverse through multiple placement layers. To gain further improvements in performance, optical routing was proposed and a cost analysis study was done. The areas for the placement of waveguides were efficiently determined, which reduced delays and maximized utilization. The global router developed was integrated into a simulated-annealing based floorplanner to investigate trade-offs of various objectives. Since power-supply noise suppression is of paramount importance in SOP, a model was developed for the SOP power-supply network. Decap allocation, and insertion were also integrated into the framework. The challenges in this work were to integrate computationally intensive analysis tools with a floorplanning that works to its best efficency provided the evaluation of the cost functions are rapid. Trajectory-based approaches were used to sample representative data points for congestion analysis and interpolate the the congestion metric during the optimization schedule. Efficient algorithms were also proposed for 3D clock routing, which acheived equal skews under uniform and worst thermal profiles. Other objectives such as wirelength, through-vias, and power were also handled.

Many architects report about mentally visualizing 3D aspects of their design ideas while simply working with 2D sketches of them. Indeed, in architecture, the general practice of conveying 3D building information by means of 2D drawings bears on the assumptions that every architect can mentally visualize a building in 3D by looking at its 2D drawings or sketches and that architects, as many report, can capture the 3D aspects of a building design during such 3D mental visualization practices. Additionally, many intuitively believe that the levels at which architects perform such 3D mental visualization practices is highly correlated to their spatial visualization abilities as defined by existing measures of spatial visualization ability. This thesis presents the outcomes of protocol studies and analyses that were conducted with the aim of developing an in-depth understanding about such 3D mental visualization practices and capabilities of architects on the basis of four research questions. First, what might be the nature of the 3D mental visualization phenomena that architects claim to experience: what are the features of these 3D mental visualizations as evidenced in specific tasks; and what might be the nature of the mental representations created during these visualization processes? Second, can every architect carry out these 3D mental visualization practices; might there be individual differences among architects' performances? Third, might 3D mental visualization of buildings be only an architectural skill; can non-architects, who can read 2D architectural drawings, visualize a building in 3D based on its 2D drawings and can they do so to the same levels of performance of those of architects? Fourth, might performance in 3D mental visualization tasks be related to/predicted by spatial visualization ability? The major conclusions of this thesis with regard to the first research question include that (1) architects can be visualizing the buildings in one of the two major forms or by alternatively switching between them: by imagining themselves situated within (almost) the actual size 3D building environment or by imagining a 3D small scale model of the building; (2) the mental representations they create during these visualization processes capture the various visual and spatial aspects of the buildings with a structure similar to that of an actual size or small scale model of the visualized space/form, yet the way they capture these aspects is not like the way these aspects would be captured from a certain viewpoint in reality; and (3) what they experience during these visualization processes is not like the continuous holistic visuospatial experience that one would have when looking at a building or walking inside/around a building. With regard to the second, third and fourth research questions this thesis concludes that (question 2) architects differ in their 3D mental visualization skills; (question 3) 3D mental visualization is an architectural skill in that it relies on certain abilities that become heightened in architects, possibly during education; and (question 4) 3D mental visualization skills are not related to spatial visualization ability as defined by the standard paper-folding test of spatial visualization ability.

In general, stereovision can be defined as a two part problem. The first is the correspondence problem. This involves determining the image point in each image of a set of images that correspond to the same physical point P. We will call this set of image points, N. The second problem is the reconstruction problem. Once a set of image points, N, that correspond to point P has been determined, N is then used to extract three dimensional information about point P. This master's thesis presents three novel solutions to the reconstruction problem. Two of the techniques presented are for detecting the location of a 3-D point and one for detecting a line expressed in a three dimensional coordinate system. These techniques are tested and validated using a unique 3-D finger detection algorithm. The techniques presented are unique because of their simplicity and because they do not require the cameras to be placed in specific locations, orientations or have specific alignments. On the contrary, it will be shown that the techniques presented in this thesis allow the two cameras used to assume almost any relative pose provided that the object of interest is within their field of view. The relative pose of the cameras at a given instant in time, along with basic equations from the perspective image model are used to form a system of equations that when solved, reveal the 3-D coordinates of a particular fixed point of interest or the three dimensional equation of a fixed line of interest. Finally, it will be shown that a single moving camera can successfully perform the same line and point detection accomplished by two cameras by altering the pose of the camera. The results presented in this work are beneficial to any typical stereovision application because of the computational ease in comparison to other point and line reconstruction techniques. But more importantly, this work allows for a single moving camera to perceive three-dimensional position information, which effectively removes the two camera constraint for a stereo vision system. When used with other monocular cues such as texture or color, the work presented in this thesis could be as accurate as binocular stereo vision at interpreting three dimensional information. Thus, this work could potentially increase the three dimensional perception of a robot that normally uses one camera, such as an eye-in-hand robot or a snake like robot.

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Mechanical and Aerospace Engineering." Includes bibliographical references (p. 116-118).

D. Tech. Electrical Engineering. / In the past few years, mesh representation of images has attracted a lot of research interest due to its wide area of applications in image processing. Mesh representation showed encouraging results for image segmentation, reconstruction and compression. The present work revisits the Laplacian mesh smoothing, a technique for fairing surfaces, almost exclusively applied to 3D meshes. The report is also based on the idea that while sampling points in an image are distributed uniformly, the information in an image is not following a uniform distribution. Instead of filtering the gray levels of the image, the proposed method, called grid smoothing, filter the coordinates of the sampling points of the image.

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