The objective of this thesis is to present the fabrication of a multiphoton microscope and the underlying theory responsible for its proper functioning. A basic introduction to nonlinear optics will give the necessary knowledge to the reader to understand the optical effects involved. Femtosecond laser pulses will be presented and characterized. Each part of the microscope, their integration and the design of the microscope will be discussed. The basic concepts of laser scanning microscopy are also required to explain the design of the scanning optics. Fast scanning problems and their solutions are also briefly viewed. As a working proof, the first images taken with the microscope will be presented. Fluorescent beads, rat tail tendon, gold nanoparticles and pollen grain images using various nonlinear effects will be shown and discussed.

The importance of root systems for soil-based resource acquisition by plants has long motivated researchers to quantify the complexity of root system structures. However, most of those studies proceeded from 2-D spatial data, and thus lacked the relevance of a 3-D analysis. In this project, helical CT scanning was applied to study root systems with an unprecedented level of accuracy, using non-destructive and non-invasive 3-D imaging that allowed for a spatio-temporal analysis. The appropriate CT scan parameters and configuration were determined for root systems of maize seedlings grown in sand and loamy sand. It was found that the soil conditions allowing for better visualization were sand before watering and loamy sand after watering. Root systems were CT scanned and visualized either at a single moment in time or repeatedly on successive days. Complexity analysis was performed by estimating the fractal dimension on skeletonized 3-D images of root systems.

This thesis aims at detecting obstacles using a single camera in an unknown 3D world for 3D motion of the robot/UAV. Obstacle detection is a pre-requisite for collision-free motion of robots/UAVs. Most of the research in this area has been for 2D motion of the ground robots and with active sensors e.g Laser range finders, Ultrasonic sensors, SONAR, RADAR etc. The passive camera based research has mostly been done either using triangulation/stereo vision (using more than one camera), or, developing an expectation map pre-hand, of the world and comparing it with the new image data. In contrast, this thesis, aims at finding solution of the problem using just a single camera in a perfectly unknown world. This requirement is based on the fact that at least a single camera would be carried by almost all robots/UAVs anyway in foreseeable future. Hence the attempt is to use the same camera for obstacle detection and avoidance task as well, so as to come up with a low cost and light weight solution, in order to facilitate building miniature robots/UAVs.

Abstract Both qualitative and quantitative limitations of two-dimensional (2DE) imaging have lead to the emergence of the three-dimensional echo (3DE) technique. Until recently the development of 3DE technology has been slow due to inferior image quality and longer processing and acquisition times compared with 2DE. However, in recent times 3DE technology has advanced to “real-time” (RT3D) and has become feasible as a standard clinical tool. The overall hypothesis of the studies undertaken in this thesis is that the increased accuracy of left ventricular (LV) assessment using RT3D justifies its use in clinical decision-making based on both single and sequential measurements in routine echocardiographic practice. It shows the increased accuracy and feasibility of 3DE using online and offline techniques and opacification, and evaluates the prognostic implications of LV measurements globally and regionally using 3DE compared with 2DE. Further, it assesses the accuracy of LV assessment using 3DE and demonstrates its superior accuracy to 2DE in cross-sectional studies. The thesis initially reviews the use of physiologic parameters used for clinical decision making and looks at the principles of incremental value in diagnostic testing. The assessment of ventricular structure and function is discussed as well as the current problems with clinical echocardiography, which have lead to the evolution and development of 3DE. The second chapter describes the methodologies used in this thesis, with particular emphasis on new technologies used in the studies. Chapter 3 looks at the role of experience as a barrier to incorporation of 3DE into standard practice. We tested attendees before and after an intensive interactive training course to evaluate the learning curve. An interactive teaching course with rehearsal and direct mentoring appears to overcome this limitation and may improve the uptake of the 3DE technique. Chapters 4 to 6 validate the use of 3DE by comparing it to 2DE and magnetic resonance imaging (MRI) with respect to online and offline techniques, the use of left ventricular opacification (LVO) and the serial follow-up of patients. The availability of automated on-line software may increase the feasibility of real-time 3DE for LV volume calculation in clinical practice. Chapter 4 looks at the comparison of off- and on-line approaches with magnetic resonance imaging. Online measurement of LV volumes was found to be feasible and more accurate than with 2DE, however the offline approach was more accurate - although more time-consuming. Chapter 5 involves two studies which sought to validate 3DE in a multicentre setting. They examine the variability of LV measurements across multiple sites and to validate 3DE against MRI. The first study found that the semi-automated measurement of 3DE reduces the variation of LV volume between centers. The second study provides information on the role of different potential sources of error and provides guidelines for future users on how to minimize these errors as well as how to interpret their findings. The next chapter further validates 3DE with use of LVO as a technique to improve the accuracy of LV volume measurements. We sought to examine the accuracy of non-contrast and contrast enhanced 2DE and 3DE for calculation of LV volumes and ejection fraction (EF), relative to cardiac magnetic resonance imaging. 2DE with LVO was analogous to 3DE in accurate categorization of LV function. However, 3DE with LVO was feasible and superior to other non-contrast and contrast enhanced techniques in patients with previous infarction. Chapter 7 examines the technical details of regional volume measurements. The use of a fixed external frame of reference in analyses of regional wall motion in the apical four-chamber view is prone to a systematic error and the use of a floating-axis analysis corrects for this, but this is based on landmarks by MRI (apex, annulus) and center of mass by 3DE. The axis is likely to be influenced by reverse remodeling after intervention and therefore we sought to evaluate 3DE regional volume assessment vs. cardiac MRI over follow-up. The use of a center-line based on center of mass with RT3D may contribute to problems with use of this modality to track regional volumes over time. Although global 3DE volumes compare well with MRI volumes, new developments in image quality and automated software will be needed before changes in regional volumes can be reliably followed with 3DE. 2DE ESE is limited by sampling in standard imaging planes and suboptimal acquisition may cause poor matching of pre- and post-stress images. 3DE may avoid these orientation problems and contraction front mapping (CFM) may also provide a method for defining the temporal homogeneity of contraction. Chapter 8 examines the incremental benefit of 3DE CFM to 2DE and 3DE, using coronary angiography as the reference standard. It found that analysis of the temporal distribution of contraction may be an alternate means than 3DE wall motion assessment for identification of ischemia for ESE. Another significant validation needed for 3DE is not only for the LV but for the right ventricle (RV). The non-geometric nature of the RV makes it difficult to measure. Chapter 9 shows that 3DE is superior to 2DE for follow-up of RV function by validation vs. cardiac MRI. It was found that 3DE was indeed more accurate than 2DE approaches and reduces test-retest variation of RV volumes and EF measurements in follow-up RV assessment. Chapter 10 investigates the accuracy and reproducibility of the use of 3DE for serial follow-up of LV measurements. Echocardiographic follow-up of LV volumes is difficult because of the test-retest variation of 2DE. In this follow-up study, sequential 3DE measurements of change of volumes and EF were similar to those obtained using MRI, but 2DE overestimated change in EDV. As MRI is expensive, of limited availability and cannot be performed on patients with implanted devices, 3DE appears to be an effective long-term follow-up imaging tool for when sequential measurement of LV volumes is sought to guide management decisions. Chapter 11 investigates whether 3DE is more predictive of outcome than 2DE. In this outcome study, 3DE measurements of ESV and EF showed a stronger prediction of outcomes than 2DE. 3DE now appears to be the measurement of choice for when LV volumes and EF are sought to guide management decisions. In conclusion, the work reported in this thesis demonstrates that 3DE increases the accuracy of LV assessment and justifies its use in clinical decision-making based on both single and sequential measurements in routine echocardiographic practice.

Automated facial metrology is the science of objective and automatic measurement of the human face. There are many reasons for measuring the human face. Psychologists are interested in determining how humans perceive beauty, and how this is related to facial symmetry [158]. Biologists are interested in the relationship between symmetry and biological fitness [124]. Anthropologists, surgeons, forensic experts, and security professionals can also benefit from automated facial metrology [32, 101, 114]. This thesis investigates the concept of automated facial metrology, presenting original techniques for segmenting 3D range and colour images of the human head, measuring the bilateral symmetry of n-dimensional point data (with particular emphasis on measuring the human head), and extracting the 2D profile of the face from 3D data representing the head. Two facial profile analysis techniques are also presented that are incremental improvements over existing techniques. Extensive literature reviews of skin colour modelling, symmetry detection, symmetry measurement, and facial profile analysis are also included in this thesis. It was discovered during this research that bilateral symmetry detection using principal axes is not appropriate for detecting the mid-line of the human face. An original mid-line detection technique that does not use symmetry, and is superior to the symmetry-based technique, was developed as a direct result of this discovery. There is disagreement among researchers about the effect of ethnicity on skin colour. Some researchers claim that people from different ethnic groups have the same skin chromaticity (hue, saturation) [87, 129, 206], while other researchers claim that different ethnic groups have different skin colours [208, 209]. It is shown in this thesis that people from apparently different ethnic groups can have skin chromaticity that is within the same Gaussian distribution. The chromaticity-based skin colour model used in this thesis has been chosen from the many models previously used by other researchers, and its applicability to skin colour modelling has been justified. It is proven in this thesis that the Mahalanobis distance to the skin colour distribution is Gaussian in both the chromatic and normalised rg colour spaces. Most facial profile analysis techniques use either tangency or curvature to locate anthropometric features along the profile. Techniques based on both approaches have been implemented and compared. Neither approach is clearly superior to the other, but the results indicate that a hybrid technique, combining both approaches, could provide significant improvements. The areas of research most relevant to facial metrology are reviewed in this thesis and original contributions are made to the body of knowledge in each area. The techniques, results, literature reviews, and suggestions presented in this thesis provide a solid foundation for further research and hopefully bring the goal of automated facial metrology a little closer to being achieved.

Thesis (Ph. D.)--University of Wyoming, 2005. / Title from PDF title page (viewed on Nov. 1, 2007). Includes bibliographical references.

Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: p. 387-400.

Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 18, 2008) Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 147-154) Also available in print.

Thesis (Ph.D.)--University of Melbourne, Dept. of Geomatics, 2007. / Typescript. Includes bibliographical references (leaves 197-216).