Theses

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  • A Hybrid Multiresolution Texture Segmentation and its Application to Ikonos Satellite Imagery
    A Hybrid Multiresolution Texture Segmentation and its Application to Ikonos Satellite Imagery
    In this thesis a method for segmenting textured images using Gabor filters is presented. One of the most recent approaches for texture segmentation and analysis is multi-channel filtering. There are several applicable choices as filter banks which are used for textured images. Gaussian filters modulated by exponential or by sinusoidal filters, known as Gabor filters, have been proven to be very usefyl for texture analysis for the images containing specific frequency and orientation characteristics. Resembling the human visual cortical cells, Gabor function is a popular sub-band filter for multi-channel decompositon. Optimum joint spatial/spatial frequency uncertainty principle and its ability to recognize and pass specific frequencies and orientations are attributes of Gabor filter that make it more attractive. Gabor function with these attributes could simulate the task of simple visual cells in the cortex. Gabor function has several parameters that determine the sub-band Gabor filter and must be determined accurately to extract the features precisely for texture discrimination. A wide selection range for each parameter exists and many combinations of these parameters are possible. Accurate selection and combination of values for the parameters are of crucial importance. Hence a difficult goal is minimizing the number of filters. On the other hand a variety of approaches of texture analysis and recognition have been presented in remote sensing applications, including land cover/land use classification and urban scene segmentation. With the avaiability of very high-resolution commercial satellite imagery such as IKONOS, it is possible to obtain detailed information on urban land use and change detection that are of particular interest to urban and regional planners. In this thesis considering the attributes of human visual system, a hybrid algorithm is implemented using multi-channel decomposition by Gabor filter bank for feature extraction in conjunction with Artificial Neural Networks for both feature reduction and texture segmentation. Three approaches are implemented to optimize Gabor filter bank for image segmentation. Eventually the proposed method is successfully applied for segmentation of IKONOS satellite images.
    A Hybrid Rate Adaptation Framework for MPEG-4 FGS Video Streaming Over IP
    A Hybrid Rate Adaptation Framework for MPEG-4 FGS Video Streaming Over IP
    There are increasing demands for real-time streaming video applications over the Internet. However, the current generation Internet was not originally designed for real-time streaming applications and only provides best-effort services, so there are many challenges in the deployment of video streaming applications over the Internet. This thesis investigates a hybrid end-to-end rate adaptation framework that provides application-level enhancements to achieve Quality of Service (QoS) for MPEG-4 FGS-Encoded video bandwidth on the path and the terminal process capabilities based on the packet-loss ratio and then determine their subscribing rate of video streams. The sender adjusts the transmission rate based on the packet-loss ratio and then determine their subscribing rate of video streams. The sender adjusts the transmission rate based on the proportion of load status feedbacks from the receivers. The sender and the receivers act together to minimize the possibility of network congestion by adjusting the transmission rate to match the network conditions. This framework achieves inter-receiver fairness in a heterogeneous multicast environment and improves QoS stability for MPEG-4 FGS video streaming over the Internet.
    A Laser Scanner And Void Visualizer For Use In A Search And Rescue Environment
    A Laser Scanner And Void Visualizer For Use In A Search And Rescue Environment
    Urban Search and Rescue (USAR) environments present many risks to emergency first responders. Technologies that can allow people to explore dangerous locations in great detail while being physically separate from them are of great value. This thesis provides an intuitive 3D viewing application called Voidviz for just that purpose, with features specifically designed for USAR and bomb identification. It is tested using 3D data gathered by two devices: a computerized theodolite, and a custom built laser scanner. The theodolite was found to be impractical for scanning dangerous locations due to its low resolution and slow speed, but the custom laser scanner was able to gather high resolution data at a useful speed. This thesis shows that useful data can be derived from sufficiently detailed simulations of voids within building collapses and unexploded explosive devices. This data can be used to increase the situational awareness of first responders.
    A Little Birdie Told Me: Journalistic and Individualistic Twitter Use of Local Television News Reporters
    A Little Birdie Told Me: Journalistic and Individualistic Twitter Use of Local Television News Reporters
    Twitter is a social networking platform that connects its users to information in the form of posts that are a maximum of 140 characters long. Twitter has become an important method for news distribution for both print and broadcast news stations. News organizations, individuals and journalists all use Twitter for different purposes, which raises questions as to how local television news reporters tweets both as journalists and as individuals. This study analyzes the tweets of the personal Twitter accounts of five local television news reporters from each of the local television news stations in Toronto (City News, CTV Toronto, Global Toronto, CP24 and CBC Toronto). Findings reveal the existence of blurring of personal (individualistic) and professional (journalistic) uses of Twitter. The tweets from the personal Twitter accounts of local television news reporters in Toronto suggest that while these reporters still take their gatekeeping roles as journalists seriously, they sometimes take advantage of Twitter as a platform that encourages public declaration and personal observations
    A Local Scale Modeling Study of Mercury Depletion Event at Canadian Arctic
    A Local Scale Modeling Study of Mercury Depletion Event at Canadian Arctic
    A modeling study was conducted on the transformation and deposition patterns of atmospheric mercury in the Canadian Arctic. One Dimensional (1-D) local scale model was used to simulate the episodic depletions of gaseous elemental mercury (GEM) after polar sunrise at Alert, Canada. The model was developed by starting with existing meteorological model (LCM-Local Climate Model) which is coupled with Canadian Aerosol Module (CAM) and then adding modules specific to atmospheric mercury chemistry. The model is able to simulate local scale transport of mercury over the entire depth of the troposphere with a basic time step of 20 min. and incorporates current knowledge of transformation reactions of atmospheric mercury species. Three mercury species Hg(O), Hg(II) and Hg(p) were considered. The developed model was applied to a portion of the Canadian Arctic region, Alert, for the month of April 2002. The model was then evaluated by comparing model estimates of mercury species concentrations with the measurement data collected in the Canadian Arctic by Meteorological Services of Canada, Downsview, Ontario. The results from this modeling study agree reasonably well with some underestimation caused by lower conversion of gaseous elemental mercury (GEM) into reactive gaseous mercury (RGM) and subsequent conversion to total particulate mercury (TPM). A sensitivity analysis was also conducted to examine the depositions of mercury species in response to changes in ozone and soot concentrations.
    A Local-Feedback-Global-Cascade Model for Hierarchical l Heart Rate Variability in Healthy Humans
    A Local-Feedback-Global-Cascade Model for Hierarchical l Heart Rate Variability in Healthy Humans
    A broad view on Heart Rate Variability (HRV) study is made and the hierarchical structure is shown in Local-Feedback-Global-Cascade (LFGC) model, which is built to explore the role of reflex feedback. This feedback, which integrates additive and multiple functionalities in multifractal cascade models, functions on the She-Waymire (SW) form of the hierarchical structure so that the concept of defect dynamics can be applied to LFGC model. The experimental evidence verified the existence of the hierarchical structure and showed discrete scale invariance in data supported the additive feedback law, which may exist in the cardiovascular system in harmony with this dynamical cascade model.
    A Narrative Study of the Experiences of Providing Culturally Competent Care by Frontline Staff Caring for Older Ukrainian Immigrants in a Mono-culture Long-term Care Facility
    A Narrative Study of the Experiences of Providing Culturally Competent Care by Frontline Staff Caring for Older Ukrainian Immigrants in a Mono-culture Long-term Care Facility
    Frontline healthcare providers are increasingly called to demonstrate respect for clients’preferences by providing culturally competent care as part of person-centered approaches. Review of literature, however, shows culturally competent care practices have been poorly integrated into healthcare. Among Canada’s population, care of older Ukrainian immigrants has received limited consideration. This narrative study explored experiences of two Ukrainian nurses providing culturally competent care in Ukrainian long-term care homes in the Greater Toronto Area. Textual and photographic data were analyzed via categorical-content and visual analysis approaches in keeping with narrative methodology. Three levels of data analysis were completed: emergent theme analysis, comparative theme analysis, and metaphoric representative analysis. Major themes include honoring the client, home is where the varenyky are served, the culturally competent nurse as the doorway to culturally competent care, and cultural insight as the solid foundation. Study implications are for organizational practice, policy and research.
    A New Dynamic Finite Element Formulation with Applications to Composite Aircraft Wings
    A New Dynamic Finite Element Formulation with Applications to Composite Aircraft Wings
    This thesis presents a new dynamic finite element (DFE) formulation for the free vibration of composite wings modelled as beam assemblies. Implementing Euler-Bernoulli beam theory, the initially assumed uniform beam is modelled in a progressive manner to produce a complex tapered composite thin-walled wing. The DFE employs dynamic trigonometric shape functions (DTSF's) to produce a single dynamic stiffness matrix containing both mass and stiffness properties. Then, the Wittrick-William root counting algorithm is used to solve the resulting non-linear eigenvalue problem. The effective stiffness of a flat fibrous composite beam is modelled using classical laminate theory. The effective stiffness of a thin-walled wing-box is achieved by employing a circumferentially asymmetric stiffness (CAS) configuration. The convergence of the DFE is significantly better as compared to other existing methods, the Finite Element Method (FEM) and the Dynamic Stiffness Matrix (DSM), particularly for complex elements and higher modes of free coupled vibration.
    A New Model for Predicting Low Cycle Fatigue Behavior of Discontinuously Reinforced Metal Matrix Composites
    A New Model for Predicting Low Cycle Fatigue Behavior of Discontinuously Reinforced Metal Matrix Composites
    An analytical model for predicitng the crack inititation life of low cycle fatique (LCF) of discontinuously reinforced metal matrix composites (DR-MMCs) has been proposed. The effects of the volume fraction Vf cyclic strain hardening exponent n' and cyclic strength coefficient K' on the LCF crack initiation life of DR-MMCs were analyzed. While both the lower level of the plastic strain amplitude and the lower Vf were found to increase the LCF crack initiation resistance, the effects of n' and K' were more complicated. By considering the enhanced dislocation density in the matrix and the load bearing effect of particles, a quantitative relationship between the LCF life of DR-MMCs and particle size was also derived. This model showed that a decreasing particle size results in a longer LCF life. The theoretical predictions based on the proposed models were found to be in good agreement with the experimental data reported in the literature.
    A New Phase-Locked Loop with Active Inductor Ring Oscillator
    A New Phase-Locked Loop with Active Inductor Ring Oscillator
    Many of today's applications require that a phase-locked loop (PLL) operate at high speeds, while maintaining reasonable phase noise and jitter performance. Voltage-controlled oscillators (VCO) are important building blocks in PLLs. More importantly, the VCO is the major contributor of phase noise in a PLL. The noisy environment, mainly due to the switching noise generated by the digital portion of these systems. imposes stringent constraints on the design of VCOs, especially phase noise or timing jitter. The switching noise originated in the digital portion of the systems are coupled to the supply and ground rails of the VCO of PLLs. Another important block of a PLL is the charge-pump, a block that is responsible for generating the control voltage to be applied to the VCO. The stability or fluctuation of the control voltage, can severely affect the phase noise performance of the VCO. The research in this thesis, centered on (i) the design considerations of CMOS charge-pumps, (ii) the timing jitter of the delay-cells of low-voltage CMOS ring-VCOs and (iii) the design of a high-speed ring oscillator. A PLL was designed using a new active inductor 6.3-GHz ring oscillator, with a tuning range of +/- 15% was designed in 0.18um CMOS technology. The ring oscillator employed active inductor loads that resulted in an improvement of about 42% in oscillation frequency when compared to the conventional resistor loaded ring oscillator.
    A New Shape Adaptive Motion Control System
    A New Shape Adaptive Motion Control System
    In recent years there is a growing trend on integrating Computer Aid Design (CAD), Computer Aid Manufacturing (CAM) and Computer Aided Inspection (CAI). This thesis presents a new shape adaptive motion control system that integrates part measurement with motion control. The proposed system consists of five blocks: surface measurement; surface reconstruction; tool trajectory planning; axis motion control and part alignment. In this thesis, the key technology used in surface measurement and surface reconstruction is spatial spectral analysis. In the surface measurement block, a new special spectrum comparison method is proposed to find out an optimal digitizing frequency. In the surface reconstruction block, different interpolation methods are compared in the spatial spectral domain. A spatial spectral B-Spline method is presented. In the tool trajectory planning block, a method is developed to select the motion profile first and then determine the tool locations according to the reconstructed surface in order to improve the accuracy of the planned path. In the part alignment, a three-point alignment method is presented to align the part coordinates with the machine coordinates. Based on the proposed methods, a software package is developed and implemented on the polishing robot constructed at Ryerson University. The effectiveness of the proposed system has been demonstrated by the experiment on edge polishing. In this experiment, the shape of the part edges is measured first, and then constructed as a wire-frame CAD model, based on which tool trajectory is planned to control the tool to polish the edges.
    A New Strategy for Multi- Objective Dynamic and Kinematic Optimization of Robotic Manipulators with Application in Haptic Interfaces
    A New Strategy for Multi- Objective Dynamic and Kinematic Optimization of Robotic Manipulators with Application in Haptic Interfaces
    There is an increasing demand for higher performance in modern robotic applications. To meet the need for more accuracy and fast dynamic response, considering inertial effects is necessary. This thesis proposes a new global multi-objective optimization strategy to tune the geometric and dynamic capabilities of a manipulator. Then, as a case study, the kinematics and dynamic behavior of a five-bar-linkage haptic interface is analyzed and a new design procedure is obtained using a new global and constrained multi-objective technique. The minimax culling algorithm was used to design parameters for optimal kinematics and dynamic dexterity measure.