The stability of the Niagara Escarpment is of critical importance to residents of Hamilton, Ontario as it bisects and divides the lower downtown core from upper residential and commercial areas. The frequency of large rockfalls and debris slides from the exposed escarpment face has resulted in reoccurring road closures that connect these two areas and has prompted the city to seek information on the processes affecting escarpment erosion and slope stability. The research reported here examines the relationship between tree and plant growth on bedrock stability by investigating relationships between species abundance and slope profile, and the potential movement of tree roots growing in rock fractures. The contributing factors of tree growth to physical weathering processes on highly fractured bedrock remain largely unknown; however, plants are suggested to play a key role in weathering processes in the critical zone. Bedrock structure and lithology influence the establishment of vegetation, and vegetation in turn exploits bedrock joints, fractures, and bedding planes, exacerbating physical and biomechanical weathering processes. In this study, vegetation characteristics observed on different parts of the escarpment face were documented and categorized into three distinct biophysical zones: upper and intermediary plateau, bedrock face, and sloping talus. Tree growth, with the potential to enhance bedrock disaggregation through the transfer of tree bole movement to roots exploiting bedrock fractures, was particularly prevalent on areas of sloping talus. To document the potential for bedrock disaggregation through tree bole movement, triaxial accelerometers were mounted on the boles of three different tree species growing along the escarpment in Hamilton. Sampled trees varied in geographic location to allow identification of the relationship between tree bole movement, wind speed, and dominant wind direction. Both deciduous and coniferous species were monitored to determine the impacts of canopy architecture on tree sway in response to wind. Monitoring took place over several days in the months of March, May, September, and November. Recorded tree bole movement (tilt) varied between deciduous and coniferous tree species; wind speed was strongly correlated to tilt of the coniferous tree, and wind direction was strongly correlated to tilt of the deciduous trees. Overall tree bole movement was strongly influenced by diurnal cycles of air movement and was greatest in the hours around mid-day. The outcomes of this research will form an integral component of an erosion-risk assessment study conducted, in part, for the City of Hamilton and will facilitate the design and development of vegetation management strategies for the Niagara Escarpment that may reduce erosion processes and potential damages to impacted citizens and businesses. / Thesis / Master of Science (MSc) / This research examines the impact of vegetation growth on erosion processes on the Niagara Escarpment in Hamilton, Ontario. The slope of the escarpment face exerts an important control on vegetation growth which in turn affects slope stability. Documentation of the dominant vegetation species at two research sites allows the identification of three distinct vegetation zones on the upper plateau, bedrock face, and sloping talus. The movement of tree trunks in response to air movement was also measured for several days in the months of March, May, October and November. Results show that the movement of two monitored deciduous trees was most strongly correlated to wind direction, while the movement of a coniferous tree was strongly correlated to changes in wind speed. All monitored trees were strongly influenced by daily cycles of air movement which were greatest around noon. This research identifies factors that influence both vegetation growth and slope stability on the Niagara Escarpment and may be used to develop effective erosion protection and mitigation strategies.

Master of Science / Department of Clinical Sciences / Robert L. Larson / Bradley J. White / We performed research that investigated the ability of three dimensional accelerometers to classify cattle behavior and also describe the circadian patterns within that behavior. The first of three studies (validation study) tested a decision tree classification system and its ability to describe behaviors of lying, standing, and walking. Classification accuracies for lying, standing, and walking behaviors were 99.2%, 98.0%, and 67.8% respectively, with walking behavior having significantly lower accuracy (P<0.01). This study also tested the accuracy of classifying the above behaviors using different device reporting intervals, or epochs. Reporting intervals of 3, 5, and 10 seconds (s) were evaluated in their ability to describe cattle behaviors of lying, standing, and walking. Classification accuracies for the 3s, 5s, and 10s reporting interval were 98.1%, 97.7%, and 85.4% respectively, with no difference in classification accuracy of the 3s and 5s epochs (P=0.73) while the 10s epoch exhibited significantly lower overall accuracy (P<0.01). This validated accelerometer monitoring system was then implemented in two studies (Winter 2007 and Spring 2008) where the devices were used to describe behavior patterns of beef calves in a drylot production setting. Lying behavior of the cattle was analyzed and found to be significantly associated (P<0.001) with hour of the day. Calves in these studies spent most (> 55%) of the nighttime hours (2000 to 0400) involved in lying behavior and spent the least percentage of time lying (<30%) during periods of time where feed was presented at the bunk (0700 and 1700). Mean lying time was also associated with trial day (P<0.01) and most trial days (67.5%) calves spending between 45% and 55% of time lying. Variation of lying behavior was found between individuals (range 29% to 66%); however, consistency in lying behavior was found within individual calves across study periods. The accelerometer monitoring system studies presented here provide evidence these devices have utility in recording behaviors (lying, standing, and walking) of individual beef calves raised in typical production settings.

Wearable sensors can be used to monitor opioid use and other key behaviors of interest, and to prompt interventions that promote behavioral change. The effectiveness of such systems is threatened by the potential of a subject's deliberate non-compliance (DNC) to the monitoring. We define deliberate non-compliance as the process of giving one's device to someone else when surveillance is on-going. The principal aim of this thesis is to develop an approach to leverage movement and cardiac features from a wearable sensor to detect such deliberate non-compliance by individuals under surveillance for opioid use. Data from 11 participants who presented to the Emergency Department following an opioid overdose was analyzed. Using a personalized machine learning classifier (model), we evaluated if a snippet of blood volume pulse (BVP) and accelerometer data received is coming from the expected participant or an alternate person. Analysis of our classier shows the viability of this approach, as we were able to detect DNC (or compliance) with over 90% accuracy within 3 seconds of its occurrence.

This thesis addresses the hypothesis that a single, waist-mounted triaxial accelerometer (TA) can be used to monitor human movement patterns in unsupervised, freeliving subjects over extended periods, and that it can be used to quantitatively measure parameters that can provide clinical insight into the health status of the subject. A rigorous theoretical and experimental understanding of the signals obtained from a TA is developed. The effect of the placement of the TA device on the waist is explored and a model relating device position to TA signal is developed for a range of postures and activities. A classification framework for movement identification using the signals from a waist-mounted TA is presented. This framework is based on a hierarchical binary processing tree and is designed for real time use. An implementation of this framework for monitoring housebound patients is presented. Algorithms for detecting falls, distinguishing between activity and rest, classifiying transitions between different postural orientations, and for identifying periods of standing, sitting, lying and walking are developed. In evaluation studies performed in controlled laboratory conditions, every algorithm performed with better than 90% accuracy. Once movements are identified, movement-specific parameters sensitive to changes in functional status are extracted from the signal. A two stage methodology for employing the accelerometry system in monitoring free-living subjects is introduced. The first stage involved monitoring specific movements through a directed routine. The second stage involved monitoring of free movement. Signals obtained from the directed routine are used to extract clinically relevant, movement-specific parameters. Signals obtained from the period of free movement are monitored for falls and other abnormal events. General parameters of movement, including energy expenditure, are also measured. The system was evaluated in a series of field studies in laboratory and home environments, in supervised and unsupervised settings, using cohorts of healthy subjects. A pilot trial was conducted in which six healthy elderly subjects wore the TA device for a period of up to three months. The technical performance and useability of the system were evaluated. Clinically significant parameters were measured and the effects of age and health status on the measured parameters were evaluated.

[pt] Desde o final da década de 80 a indústria de fibras óticas têm passado por avanços consideráveis. Através de técnicas controladas, as fibras ópticas podem gerar sinais associados a uma vasta gama de grandezas físicas funcionando como sensores denominados de Sensores a Fibra Óptica (SFO s). Diversas técnicas podem ser empregadas para tal, e entre as existentes a baseada em redes de Bragg é a que mais tem se destacado. O interesse por transdutores empregando esta técnica se justifica pelas vantagens proporcionadas pelo uso da luz, tais como sua capacidade de multiplexação, boa relação sinal/ruído, medições a longas distâncias, imunidade a campos eletromagnéticos, ausência de faísca, entre outras. Neste trabalho buscou-se desenvolver um transdutor e uma técnica de medição baseada em sensores a rede de Bragg para medição de vibrações mecânicas. Um acelerômetro óptico triaxial é projetado e construído. Diferentes modelos foram testados em busca das características de desempenho desejadas. Simulações numéricas empregando o método dos elementos finitos auxiliaram na decisão por melhores desenhos para o transdutor. Resultados de testes experimentais e calibrações empregando um sistema de aquisição de sinais desenvolvido são mostrados. Medições de longa duração para avaliação de estabilidade do sistema e efeitos de temperatura também são apresentados. / [en] Since the end of the 1980s, the fiber optics industry has experienced considerable advances. Through a number of controlled techniques, fiber optics can generate signals associated with a vast array of physical measures, working as sensors denominated Optical Fiber Sensors (OFS s). Many different techniques can be employed to achieve this objective. Among these, the one based on Bragg networks has received the greatest amount of attention. The interest in transducers employing this technique is justified by the advantages of using light, such as its multiplexing capability, good signal-to-noise ratio, possibility of long distance measurements, immunity to electromagnetic fields, and absence of sparks. In the present work, a transducer and measurement technique based on Bragg network sensors vibration are developed, in order to measure mechanical vibrations. A triaxial optical accelerometer is designed and built. Different models are tested in the search for the desired performance characteristics. Numerical simulations employing the finite element method help the decision making process for better transducer designs. Results from experimental and calibration tests using a newly developed signal acquisition system are presented. Long duration measurements to evaluate system stability and temperature effects are also shown.

No description available.