MRI-guided percutaneous needle-based surgery has become part of routine clinical practice. There are millions of these procedures performed in Canada. The conventional MRI-guided needle intervention is usually performed with the primary goal of navigating a needle to a target while sparing healthy and/or critical structures. Potential limitations of conventional unassisted free-hand needle placement include the physician's ability to align and maintain the correct trajectory and angle toward a target, especially in case of deep targets. In contemporary practice, images are displayed on the operator's 2D console only outside the treatment room, where the physician plans the intervention. Then the physician enters the room, mentally registers the images with the anatomy of the actual patient, and uses hand-eye coordination to execute the planned intervention. Previous concept has been shown and preliminary results discussed from demonstrated MRI-guided needle intervention using an augmented reality 2D image overlay system in a closed configuration 1.5T MRI scanner. However, the limited availability of interventional MR imaging systems and the length of time of MR-guided interventions have been limiting factors in the past. This dissertation addresses topics related to evaluating and developing the 2D augmented reality system, the assistance device for MRI-guided needle interventions. This research effort has primarily focused on developing a new adjustable 2D MR image overlay system and validating the previous 2D image overlay system in the clinical environment. The adjustable system requirement is to overcome the oblique insertions, difficulties inherent to MR-guided procedures, and to promise safe and reliable needle placement inside closed high-field MRI scanners. This thesis describes development of the image overlay system including requirements, mechanism design and evaluation of MR compatibility. Additionally, a standalone realization of an MR image overlay system, named “The Perk Station” was developed, implemented and evaluated. The system was deployed in the laboratory as a training/teaching tool with non-bio-hazardous specimens. This laboratory version of the system allows for evaluation of trial interventions. The system also supports recording of the complete intervention trajectory for operator performance, technical efficacy, and accuracy studies of insertion techniques. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2013-09-30 22:21:51.469

Objectives. To see whether a cognitive behavioural guided self-help approach can reduce mental health symptoms, which patients might benefit most, and whether such a treatment increases self-efficacy and internal locus of control. Design. Repeated measures and correlational designs were used. Methods. 173 patients were recruited at a cognitive behavioural guided self-help clinic in Edinburgh, of which 97 completed the three-session intervention. Verbal IQ was estimated with the National Adult Reading Test (NART). Measures of emotional symptoms, self-efficacy and locus of control were taken before and after treatment, with follow-up at one month and six months. Results. Patients completing the intervention made favourable gains, which were maintained at six months. Self-efficacy and locus of control measures were not robustly correlated with mental health improvement, but did show pre- to posttreatment changes in themselves. Conclusions. Guided self-help appears to be a useful treatment option for those with depression, anxiety and stress. The implications of the findings, the strengths and limitations of the study, and areas for future research are discussed.

The waveguiding effect of spatial solitary waves in nonlinear optical media has been suggested as a potential basis for future all-optical devices, such as optical interconnects. It has been shown that low power (∼ mW) beams, which can encode information, can be optically steered using external electric fields or through interactions with other beams. This opens up the possibility of creating reconfigurable optical interconnects. Nematic liquid crystals are a potential medium for such future optical interconnects, possessing many advantageous properties, including a “huge” nonlinear response at comparatively low input power levels. Consequently, a thorough understanding of the behaviour of spatial optical solitary waves in nematic liquid crystals, termed nematicons, is needed. The investigation of multiple beam interaction behaviour will form an essential part of this understanding due to the possibility of beam-on-beam control. Here, the interactions of two nematicons of different wavelengths in nematic liquid crystals, and the optical steering of nematicons in dye-doped nematic liquid crystals will be investigated with the aim of achieving a broader understanding of nematicon interaction and steering. The governing equations modelling nematicon interactions are nonintegrable, which means that nematicon collisions are inelastic and radiative losses occur during and after collision. Consequently numerical techniques have been employed to solve these equations. However, to fully understand the physical dynamics of nematicon interactions in a simple manner, an approximate variational method is used here which reduces the infinite-dimensional partial differential equation problem to a finite dynamical system of comparatively simple ordinary differential equations. The resulting ordinary differential equations are modified to include radiative losses due to beam evolution and interaction, and are then quickly solved numerically, in contrast to the original governing partial differential equations. N¨other’s Theorem is applied to find various conservation laws which determine the final steady states, aid in calculating shed radiation and accurately compute the trajectories of nematicons. Solutions of the approximate equations are compared with numerical solutions of the original governing equations to determine the accuracy of the approximation. Excellent agreement is found between full numerical solutions and approximate solutions for each physical situation modelled. Furthermore, the results obtained not only confirm, but explain theoretically, the interaction phenomena observed experimentally. Finally, the relationship between the nature of the nonlinear response of the medium, the trajectories of the beams and radiation shed as the beams evolve is investigated.

The U.S. Army and Marine Corps are developing guided munitions for cannon artillery. These munitions provide a significant increase in range and accuracy, but the tactics, techniques, and procedures used to employ them have yet to be developed. This study is intended to assist with that development by providing a method to determine when to use these munitions rather than conventional munitions in order to achieve a tactical-level commander's desired objectives. A combination of multi-attribute utility theory and simulation are used to determine the best ammunition (precision or conventional) to fire under certain battlefield conditions. The simulation, developed by the U.S. Army Research Laboratory, provides results on the full range of artillery effects by varying the different battlefield conditions that have the greatest effect on the accuracy of artillery. The results of simulated artillery fire missions are studied to determine the combination of battlefield conditions that produce the best results for each type of ammunition. A decision model is used to account for a commander's expected preferences based on tactical considerations. The results vary greatly depending on the battlefield conditions and the commander's preferences. One type of projectile does not clearly dominate the other.

This thesis analyzes Libya's historic 2003 decision to abandon its weapons of mass destruction (WMD) programs. In the 2 years following the decision, several theories have emerged to explain why the Libyan regime renounced these dangerous weapons. The author uses current literature and relevant sources to analyze the three most probable external causal factors: sanctions and diplomacy, intelligence, and coercive diplomacy. He finds that sanctions, diplomacy, and intelligence were significant in altering the Libyan cost-benefit analysis in favor of the West. These findings have political and theoretical implications. Lessons learned from the Libyan case will not be effective against Iran and North Korea due to differences between these countries' proliferation motivation levels and the Libyan case. However, the influence strategies that were effective against Libya are likely to be applicable in other situations. The author finds that more research is still needed to identify the conditions when different strategies are most likely to be effective.

<p>Interacting with the world is a two-step process of accurate sensing followed by coordinated movement. Optimization of biologically-inspired robotic systems benefits from the quantification and modeling of natural sensorimotor behavior, including the bottom-up circuits that mediate it and top-down cognitive influences that modulate it. A critical sensorimotor behavior in everyday life is the generation of rapid eye movements, called saccades. By making saccades 2-3 times/second, we scan visual scenes and integrate the incoming visual signals to construct an internal representation of what is around us. Much is still unknown about the neural processes that act on visual input and the nature of the resulting internal construct. To study this, we first created a model with architecture inspired by known visuomotor circuits in the brain. By training the model to achieve visuomotor stability while varying its visual and motor inputs, we found that it converged onto a solution that resembled and explained a dynamic neural process that had been documented electrophysiologically. Second, in a psychophysical experiment, we kept constant the visual stimuli and motor actions but manipulated the expectations of what subjects thought would happen. We found that visual perception systematically changes based on expectation, providing evidence for cognitive influences on visuomotor integration and continuity. Third, we expanded the work to whole-body orienting in an immersive virtual environment. While performing a marksmanship task, subjects learned to precisely intercept moving targets. Analysis and modeling of the dynamics of movement revealed mechanisms of learning in this realistic behavioral context. Taken together, the studies provide a link between the ensemble activity of neurons and perceptual experience, demonstrate that perception is a combination of incoming signals and prior beliefs, and move the field toward the study of perception-action cycles during natural human behavior.</p> / Dissertation

The purpose of this study was to determine the effectiveness of the guided daydream technique as a method for selection of a vocation and major area of study by college students seeking vocational counseling. Choices made by each student were rated by three judges relative to their degree of correspondence with the results of a specific battery of vocational tests which that student had taken. The ratings of these students' choices were compared with similar ratings made by the same judges on a control group of students who had also made choices of vocation and college major but had not participated in the guided daydream session.

Guided reading, as developed by Fountas and Pinnell (2001), has been a staple of elementary reading programs for the past decade. Teachers in the elementary school setting utilize this small group, tailored instruction in order to differentiate and meet the instructional needs of the students. The literature shows academic benefit for students who have special needs, such as learning disabilities, autism, and hearing impairments but consideration of academic impact has not been investigated for regular education students. The purpose of this quasi-experimental study was to investigate the academic impact of the use of content-related (Group C) and the traditional literature-based (Group L) reading materials. During the Living Systems and Life Processes unit in science, two teachers self-selected to utilized science-related materials for guided reading instruction while the other three teacher participants utilized their normal literature-based guided reading materials. The two groups were compared using an ANCOVA in this pre-test/post-test design. The dependent variables included the Reading for Application and Instruction assessment (RAI) and a Living Systems and Life Processes assessment (LSA). Further analysis compared students of different reading levels and gender. The data analyses revealed a practical but not statistical significance for students in science performance. It was discovered that below level male and female students performed better on the LSA when provided with content-related guided reading materials. As far as reading achievement is concerned, students in both groups had comparable results. The teachers provided guided reading instruction to their students with fidelity and made adjustments to their practices due to the needs of their students. The content-related teachers utilized a larger number of expository texts than the literature-based teachers. These teachers expressed the desire to continue the practice of providing the students with content-related materials.

Approved for public release; distribution is unlimited / The Tomahawk Land-Attack Missile (TLAM) is the long-range precision weapon of choice in strike warfare against strategic targets for U.S. military forces. Predesignation is the process of determining which ship or submarine will fire which TLAM missiles in support of an authorized attack upon specified targets. This thesis revisits the mathematical models and algorithms developed by previous NPS faculty and students to optimally conduct the allocation of TLAMs to firing units. We incorporate all the problem specifications addressed by previous heuristic algorithms for the problem, and compare our results to those in publicly available test cases. We show that our models can be solved optimally in affordable time for most of the cases and make provisions to establish accurate bounds in the other cases. / First Lieutenant, Turkish Army

Teacher educators continually strive to find ways to improve the preparation of preservice teacher candidates. In the area of mathematics education, methods courses that follow National Council of Teachers of Mathematics (NCTM) standards for professional development have been successful. This study supports the notion that a mathematics methods course can improve mathematics teaching efficacy in the constructs of personal mathematics teaching efficacy (PMTE) and mathematics teaching outcome expectancy (MTOE). Findings also suggest that mathematics teaching efficacy is developmental in its nature with PMTE developing before MTOE. Employing a quasiexperimental nonequivalent comparison groups pre- and posttest design, the present study examined the effects of guided imagery as an added component of a mathematics methods course and found no significant advantageous treatment effects on mathematics teaching efficacy. However, there were no detrimental effects on mathematics content knowledge and pedagogical skills either. Participation in a reform-based mathematics methods course did affect mathematics teaching efficacy for both groups in the study. Mathematics teaching efficacy beliefs were measured by the Mathematics Teaching Efficacy Beliefs Instrument (MTEBI), and data were analyzed by ANCOVA and paired-samples t-tests. Recommendations for further research on the developmental nature of general teacher efficacy and mathematics teaching efficacy are included.