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The problem of tracking radar targets in the low-angle region Where conventional monopulse radars face difficulties due to the presence of multipath waves is considered in this thesis. The emphasis of the presentation is mainly directed towards finding a new simple closed-form solution to the coherent multipath problem over a smooth surface. Another concern is to improve the performance of the three-subapertures maximum-likelihood estimator when the two received signals are in-phase or anti-phase at the centre of the array. The multipath phenomenon and its modelling for smooth and rough surfaces are discussed and simulation results obtained for different surfaces. subsequently the following are treated First. a new four-subapertures technique to improve the in-phase and anti-phase performance of the maximum likelihood estimator above is derived and simulation results are shown. Then. an improved version of this technique is introduced as a part of the new algorithm. Second. a new three-subapertures trigonometric solution to solve the coherent multipath problem is derived and demonstrated by simulation results. This new method is simpler than the maximum likelihood estimator above and very similar in its estimation accuracy. Third. the performance of the maximum entropy method is tested for the coherent multipath problem by using the three-subapertures arrangement of a linear array. Finally the performances of the above three methods and the normal phase monopulse radar are tested and compared to different surfaces when the coherent and noncoherent multipath exist together. Simulation results show that the performances of the maximum entropy method and phase monopulse are much better than the others when the target is low-tlyine over a rough surface.

The huge number of cctv cameras and security applications places increasing requirements on automatic visual tracking and behaviour classification systems. The best working example of such a tracker is the human visual system (hvs) which can flawlessly detect, track and understand almost any object or event. The research described in this thesis uses lessons learnt from studies of the hvs to develop a novel approach for computerbased visual tracking. In this approach, initial detection of moving objects is achieved using a new motion distillation paradigm which employs spatio-temporal wavelet decomposition of video. The method is shown to be more robust than traditional background modelling techniques while being computationally less expensive. As with the hvs, the approach uses a dual-channel tracking architecture to perform tracking. The motion channel, generated through motion distillation, handles object detection and initialises tracking. The form channel is used to resolve tracking ambiguities and occlusions. Qualitative and quantitative tracking results illustrate the advantages of this approach. This thesis also describes a new approach to the task of ob- 4 ject (e.G. Human) behaviour analysis - a subject which is of great importance, yet which is still an under-researched aspect of visual tracking. In the work described here, objects are categorised into vehicles, pedestrians, runners, groups and unknown pedestrian behaviour.

A cardinal role of selective visual attention is to serve our action by selecting all the relevant information. One task that has been applied extensively to explore attention is visual search for a target among distractors. Given the extensive practice of human observers with visual search, and its ecological relevance, one could expect a high level of efficiency when performing visual search tasks. Indeed, a prominent in the literature Ideal Observer model (Najemnik & Geisler, 2005, 2008) suggests, that human visual system is extremely efficient, in that every eye movement during visual search is executed to the locations that could be expected to yield maximum information; similarly to the Ideal Observer, humans require the minimum number of eye moments possible to find the target (Najemnik & Geisler, 2005, 2008). The present programme of research tests the prediction of the Ideal Observer model (Najemnik & Geisler, 2005, 2008) against a simpler, but similarly effective stochastic selection model (Clarke, Green, Chantler, & Hunt, 2016), by examining human visual search strategies under normal viewing conditions, and conditions that simulate visual field deficit. Across nine experiments, I observed strikingly inefficient search behaviour that speaks against the assumptions of the Ideal Observer model. Although on the surface these cumulative results appear to be in line with the random process of fixation selection (Clarke et al., 2016), such conclusion appears to be valid only for the observed group results. The individual observer's data that was carefully documented in each of the experiments did not allow such a conclusion. The individual observers' data showed full spectrum of search strategies, with some observers being extremely efficient, some being average searchers, and others applying a very inefficient strategy. The large individual differences between participants suggest that the fixation selection process is neither optimal nor random, but rather idiosyncratic.

Hindi and Urdu are two branches of the same language sometimes known as Hindustani. They are divided by orthography and geography but when spoken are sometimes indistinguishable. Both have contributed loanwords that have now been completely assimilated into the language. The question of how the eye behaves during Hindi reading when it encounters Urdu loanwords has not been focused on extensively in prior research. The main purpose of this thesis is to document the eye behavior during reading Sanskrit-based words and Urdu loanwords in Hindi. We place fifteen word pairs consisting of one target Hindi Sanskrit-based word and its Urdu loanword equivalent in different sentences. Native Hindi speakers participate to read Hindi sentences containing either Urdu loanwords or the Sanskrit root word in Hindi. To quantify the differences in reading Hindi and Urdu loanwords in Devanagari (Hindi script) sentences we use an eye tracking methodology, which is used to measure eye movements of a participant during reading. We discover very distinctive eye behavior during reading of Urdu loanwords in comparison to reading Hindi Sanskrit-based words. Analysis also shows an interaction in eye behavior due to language and frequency.

The aim of the thesis is to develop a model-based control strategy, namely, the Model Predictive Control (MPC) method, for robot position control using artificial neural networks. MPC is primarily developed for process control. Therefore its application in robot control has been less reported. In addition, conventional MPC uses linear model of the system for prediction which leads to inaccuracy for highly non-linear systems, such as robot. In this thesis a simulation model of a modified PUMA robot is constructed. This model is built using both MATLAB/SIMULINK and FORTRAN languages. In this model, the full robot dynamics is used together with the realistic factors, such as the actuator effects and the gear backlash, to represent the real system accurately. All simulations throughout this thesis are carried out on this model. A model predictive control strategy for robot trajectory tracking is also introduced in this thesis. The feasibility of the proposed MPC control method is studied based on a perfect prediction model, a model with uncertainties, and when the frequency band of the MPC controller is limited. Furthermore, a new method of using neural networks for robot dynamics modelling is introduced. This method is developed on the basis of a numerical differential technique that eliminates the explicit requirement of robot joint accelerations. Therefore, this method can be easily implemented on physical systems. As the measurements of the robot joint positions, velocities, and torques collected from operating the robot can be used to train the neural network, a more accurate dynamic model can be obtained. Finally, the MPC control method and the neural network model are combined together to form a neural network based MPC controller. The validity of this method is verified by using simulation on the simulated robot system / Master of Engineering (Hons)

When a moving dot, which is tracked by the eyes and enclosed in a moving framework, suddenly stops while the enclosing framework continues its motion, the dot is seen to describe a curved path. This illusion can be explained only by assuming that extra-retinal signals are taken into account in interpreting retinal information. The form of the illusion, and the fact that the phenomenal path cannot be explained on the basis of positional information alone, suggests that the perceived path is computed by integrating (instantaneous) velocity information over time. A vector addition model embodying a number of simplifying assumptions is found to qualitatively fit the experimental data. A number of follow-up studies are suggested.

Data from the National Educational Longitudinal Study (NELS: 88) are used to examine differential student placement and to assess the independent effects of race on academic tracking within the vocational program. The study examines how the structure of tracking within the vocational program shapes both academic achievement outcomes and career opportunities among high school students. Student's placement in the vocational program is argued to function as a unique track program that disadvantage students academically, particularly students of color. Racial-ethnic minority students are disproportionately placed into lower level academic courses and programs including vocational education. Once so placed, their subsequent enrollment patterns in specific vocational courses may have varying effects on academic and career outcomes. Few studies have attempted to disaggregate how students are further tracked once they are placed into broad high school curriculum tracks. This study analyzes the specific variations in patterns of race-ethnic student placement within vocational programs and examines the consequences of such placement for academic achievement and career attainment outcomes. Findings reveal that several racial-ethnic variations are associated with the tracking processes within the vocational program and subsequent student academic and career outcomes. Race-ethnicity most often was negatively associated with performance on standardized achievement tests and enrollment into low vocational tracks, primarily among males. There were noteworthy gender differences in the assignment within vocational tracks, academic success, and eventual employment status and occupational placement.

Conical fluidized bed dryers are widely used in the pharmaceutical industry due to their high heat and mass transfer characteristics. Despite their widespread use, very little is known about the hydrodynamics of conical fluidized bed dryers. Wet pharmaceutical granule has high moisture content and wide particle size distribution (PSD), which can lead to poor mixing and non uniform drying. Uneven moisture content in the final product can adversely affect the quality and shelf life of these high value drugs. Previous studies on the conical fluidized bed dryers focused on the study of the gas phase, however motion of particulate phase has never been studied. Particle tracking is an important tool to study the motion of the particulate phase. Two particle tracking techniques were developed and used to study the motion of the particulate phase in a conical fluidized bed dryer. The first technique was radioactive particle tracking (RPT) which was developed at the University of Saskatchewan laboratory for a vessel having conical geometry. Experiments were conducted using dry pharmaceutical granule and during the actual drying of wet pharmaceutical granule. Two radioactive tracers of different sizes (1.6 to 2.6 mm) were tracked in each set of experiments to determine the effect of particle size on particle motion and particle mixing. Superficial gas velocities of 1, 1.5, 2 and 2.5m/s were used in dry bed studies to quantify the effect of superficial gas velocity. The second particle tracking technique was developed at the labs of Merck Frosst Canada Inc. Movies were captured using a high speed video camera coupled to a borescope and then analyzed off-line using image analysis software.Three powders having mean particle diameters of 774, 468 and 200 microns were used. Experiments were conducted at superficial gas velocities of 1.5, 2 and 3 m/s. <p>RPT revealed that there is a distinct circulation pattern of the particulate phase. Particles move upwards at high velocities near the centre of the bed and fall slowly near the walls. Furthermore, most of the gas flow is concentrated near the centre of the bed and the circulation pattern was observed at all the superficial gas velocities. Particle size of the tracer particle and PSD of the bed material had an appreciable impact on particle mixing with bigger particles exhibiting higher segregation tendencies than the smaller ones in the case of dry granule having a broad PSD. Particle segregation due to size difference was more pronounced at a superficial gas velocity of 1 m/s. However, segregation decreased with an increase in superficial gas velocity. During drying of wet granule, particle mixing and motion of the tracer particle was poor during the first 7 minutes of drying suggesting that most of the gas flow was concentrated near the centre of the bed. Particle mixing and average particle speeds increased considerably when the moisture content in the granule was less than 18 wt% suggesting a change in the hydrodynamics of the bed with the gas being more evenly distributed throughout the bed. Image analysis of high speed movies also suggested that a dilute region existed at the center of the bed. These observations were in agreement with the observations made by RPT.

There is evidence to suggest that people from different cultures have different cognitive processing styles. For example, by measuring the eye movements of American and Chinese students when viewing pictures, Chua, Boland, and Nisbett (2005) found that American students fixated more on the focal object, whereas Chinese students fixated more on the background. In a subsequent object-recognition task, the Chinese students were less likely to correctly recognize old objects presented in new backgrounds than Americans did. This study used a similar scene-viewing task to investigate whether aging modulates these cultural differences in cognitive processing style. Like Chua et al., we found that young Chinese students spent longer fixating the background than did their Western counterparts. However, we failed to replicate the accompanying memory bias observed by Chua et al. Our strongest finding was that maintaining the original background facilitated memory for objects in young participants of both cultures but not for older participants. This result suggests that older adults had poorer memory for background details and/or had poorer integration of object and background.