An interesting problem in computer vision is that of image registration, which plays an important role in many vision-based recognition and motion analysis applications. Of particular interest among data registration problems are multimodal image registration problems, where the image data sets are acquired using different imaging modalities. There are several important issues that make real-world multimodal registration a difficult problem to solve. First, images are often characterized by illumination and contrast non-uniformities. Such image non-uniformities result in local minima along the convergence plane that make it difficult for local optimization schemes to converge to the correct solution. Second, real-world images are often contaminated with signal noise, making the extraction of meaningful features for comparison purposes difficult to accomplish. Third, feature space differences make performing direct comparisons between the different data sets with a reasonable level of accuracy a challenging problem. Finally, solving the multimodal registration problem can be computationally expensive for large images. This thesis presents a probabilistic complex phase representation (PCPR) objective function for registering images acquired using different imaging modalities. A probabilistic multi-scale approach is introduced to create image representations based on local phase relationships extracted using complex wavelets. An objective function is introduced for assessing the alignment between the images based on a Geman-McClure error distribution model between the probabilistic complex phase representations of the images. Experimental results show that the proposed PCPR objective function can provide improved registration accuracies when compared to existing objective functions.

This work introduces the method of Distributed Volumetric Sources (DVS) to solve the transient and pseudosteady-state flow of fluids in a rectilinear reservoir with closed boundaries. The development and validation of the DVS solution for simple well/fracture configurations and its extension to predict the pressure and productivity behavior of complex well/fracture systems are the primary objectives of this research. In its simplest form, the DVS method is based on the calculation of the response for a closed rectilinear system to an instantaneous change in a rectilinear, uniform volumetric source inside the reservoir. Integration of this response over the time provides us with the solution to a continuous change (constantrate pressure response). Using the traditional material balance equations and the DVS pressure response of the system, we can calculate the productivity index of the system in both transient and pseudosteadystate flow periods, which enables us to predict the production behavior over the life of the well/reservoir. Solutions for more complex situations, such as sources with infinite or finite-conductivity (i.e., a fracture), are provided using discretization of the source. This work considers the case of a complex system with a horizontal well intersecting multiple transverse fractures as an example to show the ability (and flexibility) of the new method. The DVS solution method provides accurate solutions for complex well/fracture configurations — which will help engineers to design and implement optimum well completions. The DVS solutions has been validated by comparing to existing analytical solutions (where applicable), as well as to numerical (simulation) solutions. In all cases the DVS solution was successfully validated — at least in a practical sense — specifically in terms of the accuracy and precision of the DVS solution. As the DVS method is approximate (at early times), there are small discrepancies which are of little or no practical consequence. In terms of computation times, because of its analytic nature, the DVS method is not always optimal in terms of speed for certain problems, but the DVS approach is similar in computation speed with commercial reservoir simulation programs.

This study investigated the effect of bone marrow derived mesenchymal stem cells (MSCs) in a PEGylated fibrin gel (PEG) seeded into a decellularized extracellular matrix (ECM) on recovery of skeletal muscle following a volumetric muscle loss (VML) injury. Six to nine month old male Sprague-Dawley rats were used in this study. Approximately one-third of the skeletal muscle mass of the lateral gastrocnemius (LGAS) was removed from the LGAS, which was immediately replaced with an acellular ECM of the same dimensions. Seven days after injury, animals were injected with one of four solutions: saline (SAL), MSCs (MSC), PEGylated fibrin hydrogel (PEG), or MSCs in PEG (PEG+MSC). Maximal isometric tetanic tension (Po) of the LGAS was assessed fifty-six days after VML injury, followed by histological evaluation. VML injury resulted in a functional impairment of the LGAS capable of producing 76.1± 4.9% of the force generated in the non-injured contralateral LGAS. Tetanic tension of the PEG+MSC treated group was significantly higher compared to all other treatment groups (p < 0.05), although specific tension (N/cm2) in the PEG+MSC group (79.7±4.0%) was only significantly higher compared to SAL (58.2±3.0) and PEG (64.0±2.1%) treated groups (p < 0.05). However, LGAS mass was significantly higher in the PEG+MSC group compared to all other groups (p < 0.05). These findings suggest the combination of the PEG+MSC did not lead to a significant increase in muscle function compared to MSC treatment alone, and demonstrates the importance of MSCs in skeletal muscle regeneration in VML injury models. However, as evident by the significant increase in LGAS mass, PEG+MSC treatment may lead to histological differences not evaluated in this study. Gross morphology of the repaired gastrocnemius was indistinguishable from the contralateral control. / text

Visualization is the process of making something perceptible to the mind or imagination. The techniques for producing visual imagery of volumetric data have advanced immensely during the last decades to a point where each produced image can include an overwhelming amount of information. An increasingly viable solution to the limitations of the human sense of visual perception is to make use of not only vision, but also additional senses. This thesis presents recent work on the development of principles and algorithms for generating representations of volumetric data through the sense of touch for the purpose of visualization. The primary idea introduced in this work is the concept of yielding constraints, that can be used to provide a continuous set of shapes as a representation of features of interest in various types of volumetric data. Some of the earlier identified standard human exploratory procedures can then be used which enables natural, intuitive and effective interaction with the data. The yielding constraints concept is introduced, and an algorithm based on haptic primitives is described, which forms a powerful yet versatile implementation of the yielding constraints. These methods are also extended to handle time-varying, moving and low quality data. A framework for multimodal visualization has been built on the presented methods, and this is used to demonstrate the applicability and versatility of the work through several example applications taken from different areas.

An interesting problem in computer vision is that of image registration, which plays an important role in many vision-based recognition and motion analysis applications. Of particular interest among data registration problems are multimodal image registration problems, where the image data sets are acquired using different imaging modalities. There are several important issues that make real-world multimodal registration a difficult problem to solve. First, images are often characterized by illumination and contrast non-uniformities. Such image non-uniformities result in local minima along the convergence plane that make it difficult for local optimization schemes to converge to the correct solution. Second, real-world images are often contaminated with signal noise, making the extraction of meaningful features for comparison purposes difficult to accomplish. Third, feature space differences make performing direct comparisons between the different data sets with a reasonable level of accuracy a challenging problem. Finally, solving the multimodal registration problem can be computationally expensive for large images. This thesis presents a probabilistic complex phase representation (PCPR) objective function for registering images acquired using different imaging modalities. A probabilistic multi-scale approach is introduced to create image representations based on local phase relationships extracted using complex wavelets. An objective function is introduced for assessing the alignment between the images based on a Geman-McClure error distribution model between the probabilistic complex phase representations of the images. Experimental results show that the proposed PCPR objective function can provide improved registration accuracies when compared to existing objective functions.

The co-firing of biomass and coal plays an important role in increasing the biomass power capacity and reducing greenhouse gas (GHG) emissions. The challenges of the large percentage biomass co-firing (over 20% on energy basis) in existing pulverized coal boilers are keeping the same steam parameters and having a high boiler efficiency and a stable operating. The primary goal of this thesis is to develop a combustion concept for coal-fired boilers to enablea large percentage of biomass co-firing with up to a 100% fuel switch; these changes should increase the combustion efficiency, reduce CO2  and NOx emissions, improve the process efficiency, while maintaining the same steam parameters after switching fuels. To achieve these goals,  a  typical  biomass  pretreatment technology  called  torrefaction  has  been  employed to upgrade  the  biofuel  quality  in  terms  of  both  energy  density  and  chemical  properties. Consequently, a torrefaction based co-firing system has been proposed. In addition, a novel biomass combustion method called volumetric combustion has been designed; this process involves intense mixing and flue gas internal recirculation inside the combustion chamber, increasing the residence time of the biomass particles and making the temperature and gas species more uniform. In this thesis, a series of studies based on experiments, CFD modelling, and process simulations have been performed. First, the raw material was palm kernel shells (PKS) that were torrefied over same residence time but at different temperatures in a laboratory-scale torrefaction reactor, producing three torrefied biomasses with different degrees of torrefaction. The devolatilization kinetics and char oxidation kinetics were determined based a series of high-temperature high-heating-rate tests in an isothermal plug flow reactor (IPFR), the obtained kinetic parameters were adopted for CFD modeling. Continually, the numerical investigations on the flame properties of the torrefied biomass and a 220 MWe coal-fired boiler performance were conducted, to understand the predicted results of the coal-fired boiler performance at varying biomass co-firing ratios. Afterward, analyses of the impacts of the degree of torrefaction and the biomass co-firing ratio on process operation, performance and electricity efficiency of a torrefaction based co-firing power plant were performed. Finally, the properties of the pollutants emitted from biomass volumetric combustions under various combustion modes and co-firing ratios were studied using Aspen Plus. According to the results, the following conclusions can be reached: 1) a high heating rate enhances the yields of the volatiles for biomass devolatilization processes with the same final temperature; 2) the enhanced drag force on the biomass particles causes a late release of volatile matter and delays the ignition of the fuel-air mixture. Furthermore, oxidizers with lower oxygen concentrations normally generate larger flame volumes, lower peak flame temperatures and lower NO emission; 3) the co-firing simulation reveals that a boiler load reduction of less than 10% is observed when firing 100% torrefied biomass; 4) deep torrefaction is not recommended because the energy saved during biomass grinding is lower than that consumed by the additional torrefaction process; the electrical efficiency of power plant is reduced when increasing either the degree of torrefaction or the biomass substitution ratio; 5) the amount of flue gas that needs to be recycled for NOx reduction decreased when the percentage of co-fired biomass increased. Overall, from the perspective of combustion, both the torrefaction process and volumetric combustion are promising steps toward realizing large percentage biomass co-firing in coal-fired boilers with high efficiency and reduced emissions. / <p>QC 20140130</p>

Purpose: At the Wellington Blood and Cancer Centre (WBCC), Volumetric Modulated Arc Therapy (VMAT) is used to treat a variety of head and neck (H&N) cancers. Presently, the complexity of plans is limited to ensure the accuracy of patient treatment within the range of the departmental experience. The complexity limitation is applied through use of a monitor unit (MU) constraint during plan optimisation. Plans of higher complexity can be obtained by loosening the MU constraint, and setting more stringent optimisation objectives on organs at risk (OAR) and target volumes (PTV). This could potentially yield higher quality treatment plans but may also degrade the accuracy of the TPS calculation or the plan delivery at the treatment machine. The aim of this study is to investigate the level of plan complexity that results in accurate treatment plan calculation and delivery, and quantify the corresponding gain in plan quality. Methods: Five previously treated H&N patients were selected for the study. Each patient’s clinical plan was used as the lowest complexity level and labelled C1. Subsequently, an approximate pareto-optimal plan (C3) was created that focused equally on sparing spinal cord, brain stem and parotid gland while maintaining, or improving on, the previously obtained target coverage. Next, a C2 plan was created such that the plan quality was in between C1 and C3. Plan quality of each complexity level was assessed in terms of OAR sparing and PTV coverage. The average leaf pair opening (LPO), critical leaf pair opening (%LPO<1cm) and mean leaf travel were used as plan complexity metrics. The calculation and delivery accuracy of each complexity level using Varian TrueBeam LINAC/Eclipse TPS was verified using time resolved point dose measurements (TRPD), EBT film measurements (Ashland Inc.) and ArcCheck measurements (Sun Nuclear Corp.). A comprehensive uncertainty analysis was carried out including a quantification of the measurement and delivery reproducibility. Results: Increasing plan complexity from C1 to C3 reduced the Spinal Cord D1cc, Brain Stem D1 and Parotid Gland Dmean up to 14.7 Gy, 7.1 Gy and 7.8 Gy, respectively. In addition, C3 plans improved the target coverage compared to C1 plans, with the PTV66 and PTV54 D98 increasing up to 1.0 Gy and 0.6 Gy, respectively. The verification measurements showed that the plan calculation and delivery for all complexity levels was well within clinical acceptance levels (Table 1). TRPD showed that VMAT dose delivery itself was repeatable within 0.1% (1 S.D.) over 10 consecutive deliveries for both C1 and C3 complexity levels. Discussion & Conclusions: This study has shown that increasing the plan complexity can provide significant dosimetric advantages for the treatment of H&N cancer. Verification measurement results indicated that this did not noticeably degrade the calculation and delivery accuracy of VMAT using a Varian TrueBeam LINAC and our Eclipse TPS beam model. H&N VMAT at the WBCC can now be developed further with greater confidence in the dosimetric accuracy of higher complexity plans.

A prototype sensor array was developed for use with laboratory automation to permit closed-loop control of liquid-levels in a multiwell microplate geometry. A simple electrical model for non-contact capacitance-based fluid sensors was extended to describe a fluid-level dependency. The new model shows that a charge-transfer based capacitance transducer employing a liquid-specific calibration can be used to obtain an output signal that varies linearly with the liquid-level when fringe-field effects are negligible. The calibration also compensates for liquid-to-liquid conductivity and permittivity differences. / The sensor was tested using sodium chloride (NaCl) and ethanol solutions to simulate the range of conductivity and permittivity typical in biological and chemical research. Measured capacitance was a second-order function of liquid volume due to fringe-field effects and was compensated for by adding a hardware-based calibration. Liquid-volume measurement error averaged 0.2% of the 120mul fill volume with a standard deviation of 0.6% (&lt; mul). The maximum absolute error for all liquids was 2.7% (3mul).

One of the most applicable methods of low-temperature geothermal resource assessment is volumetric method. While applying volumetric method, the values of uncertain parameters should be determined. An add-in software program to Microsoft EXCEL, @RISK, is used as a tool to define the uncertainties of the parameters in volumetric equation. In this study, Monte Carlo simulation technique is used as the probabilistic approach for the assessment of lowtemperature Bal&ccedil / ova-Narlidere geothermal field. Although Bal&ccedil / ova-Narlidere geothermal field is being utilized for several direct heat applications, there exists limited data for resource assessment calculations. Assessment studies using triangular and uniform distribution type functions for each parameter gave the mean values of recoverable heat energy of the field as 25.1 MWt and 27.6 MWt, respectively. As optimistic values (90%), those values were found as 43.6 MWt and 54.3 MWt. While calculating these numbers, a project life of 25 years with a load factor of 50% is used.

Ankle sprains are one of the most common musculoskeletal injuries. Physiotherapy treatment and advice to rest, use ice, use compression, and elevate the ankle (RICE advice) is believed to speed up the functional recovery and enhance healing associated with acute ankle sprains. However, there is limited evidence to support the efficacy of RICE treatment. This study investigated whether physiotherapy (including RICE advice) was as effective as RICE advice alone in improving the time to recovery in a clinical situation.The evidence for RICE advice was reviewed along with the different treatment modalities currently used by physiotherapists in New Zealand for acute ankle sprain. This review highlighted the low number and poor quality of studies investigating RICE and early intervention physiotherapy management for ankle sprains. RICE principals appear to be relatively inexpensive and somewhat effective for pain relief and may reduce further tissue damage in the acute stage of Grade I and II ankle sprains. Evidence extrapolated from studies investigating the use of post surgical ice appears to support the use of ice in the acute stage of an ankle sprain to minimise bleeding and oedema. The intermittent application of ice is more effective for pain relief in the acute phase than sustained icing. Physiotherapy interventions such as TENS for pain relief and bracing for the support of Grade II - III ankle sprains have been shown to be beneficial for pain relief in the acute phase. A need for further high quality, randomised controlled trials (RCT's) was identified.Subsequently a RCT was conducted with 28 participants to investigate the difference between (a) early intervention physiotherapy management combined with RICE advice, and (b) self management RICE advice without physiotherapy.Twenty eight individuals (males n = 22, females n = 6), between the ages of 16 and 40 with acute ankle sprains, who met the inclusion criteria, were approached by physiotherapists working on this project and invited to participate. Dependant variables were pain, function, swelling, compliance and medication use up to Day 11 post injury. Swelling, pain and function were measured over three assessments on Days 1, 3 and 11, using volumetric analysis, a visual analogue scale (VAS) and a functional question derived from a validated functional questionnaire respectively. Medication use and compliance were elicited from information gathered in a participant home diary. Both groups were similar on Day 1 in respect to their initial pain, swelling, the number of participants who were referred for X-rays, and the time taken to present to the physiotherapist. However the RICE group had significantly higher function scores (p = 0.042). The RICE group also had a significantly higher use of medication on Day 1 (p = 0.035) and Day 11 (p = 0.048). For both groups there was a statistically significant decrease in swelling (p = 0.003), pain scores (p = 0.000), and an increase in function scores (p = 0.000) in relation to time over the eleven days of assessment. The physiotherapy group had significantly improved function scores (p = 0.042) from Day 1 to Day 11 compared to the RICE group. There were no significant differences between groups for swelling, pain scores, and their first day of documented non-compliance. The within day range of error in the volumetric measurements was within 189.9 ml and 1.2 ml. Three trials were conducted per person within a Day session. The first volumetric analysis was significantly less than the subsequent two measurements (p = 0.040).It was concluded that, in the early stage of an ankle injury both physiotherapy and RICE, and RICE advice alone, resulted in significant improvements in swelling, pain and function. Early intervention physiotherapy was significantly better at improving the functional ability of participants by Day 11. Early intervention physiotherapy may also identify complications associated with ankle sprains.Despite its limitations this research could potentially lead to changes in the standard treatment protocols for soft tissue ankle injuries. Implementation of self management RICE by patients in the acute stage would initially reduce the cost of physiotherapy treatments, and may lead to equal improvements in pain and swelling outcomes. However, it appears that physiotherapy may lead to better functional outcomes which would reduce the costs associated with time off work, and rehabilitation. It is important to note that these findings are based on a small sample size and on Grade I or II ankle ligament sprains, and that treatment for more severe ankle injuries may be better with physiotherapy, or surgery, rather than self management RICE by patients. Findings contribute to the growing body of 'best practice' evidence for health practitioners. Keywords: Acute soft tissue injuries, ankle, sprain, early intervention, physiotherapy, RICE, volumetric measurement.