<p>Home health care continues to be an important and challenging issue in most countries, especially for the elderly. To improve home health care, it would be useful to have wireless biomedical systems that can monitor various vital signs ofthe elderly and to provide such information to a health care professional. In the orient, one powerful tool in diagnosing and predicting health issues is the Traditional Chinese Pulse Diagnosis (TCPD) technique. The TCPD technique is through the examination ofthe artery pulse pattern on three points along the radial artery and it usually requires a doctor to conduct pulse palpation with their fingers. Therefore, the diagnosis relies significantly on the experience of the doctor. However, for the more widespread use of TCPD, one concept is to bring the doctor's "fingers" and "encode" the doctor's experience to an individual in a home care setting. Using existing technologies in biomedical sensor, data acquisition, communication and microelectronics, it is possible to construct a "smart" TCPD system.</p> <p>In this thesis, a microcontroller based pulse monitoring system for TCPD's application in home care is proposed. The system consists of three main units for data acquisition, data processing and wireless transmission. The pulse data acquisition is with a liquid-filled digital pressure sensor module with the employment of applanation tonometry, a technique used in recording the peripheral artery waveform. Each sensor module is read by a corresponding microcontroller via its serial peripheral interface, and the measurement is then sent wirelessly to a personal computer (PC) via a 204GHz transceiver. The system was used to successfully record and transmit radial pulse pressure and body surface temperature measurements to a host PC. Pulse waveforms are then reproduced from the pulse pressure measurements to conduct offline analysis. The analysis is targeted to integrating TCPD diagnosis with quantitative pulse representation and measurement history, to use expert knowledge in classification and recognition, and therefore to provide supporting information for disease diagnosis and forecasting.</p> <p>The work performed in this thesis presents the proof-of-concept research and system implementation in the design of an individual health monitoring system using the TCPD method. Basic pattern matching and parameter extraction/comparison are performed and verified. Finally, the research work presented here provides a solid foundation for future work in this field ofTCPD and its application.</p> / Master of Applied Science (MASc)

<p>Ubiquitous wireless sensor networks (WSNs) are expected to play an important role in the future society for various applications. As a result, carefully managing the network resources to improve the network performance becomes a hot research topic. In this thesis, we study the perfonnance ofWSNs with a cluster tree topology, where all the cluster heads (CHs) fonn a tree topology. The sensor nodes transmit data to their directly associated CHs, which forward the traffic to the sink through other CHs in the cluster tree.<br />We first study the associations between sensor nodes and the cluster heads (CHs). In a WSN where there is a strong overlapping coverage area between the CHs, associating the sensor nodes to different CHs may result in different network performance. As the sensor node associations affect the traffic load within each cluster and that between the clusters, timeline of the CHs should be allocated accordingly. We formulate three optimization problems by jointly considering the sensor node associations and CH timeline allocations. The objectives are maximizing the throughput per sensor node, balancing the energy consumption among the CHs, and maximizing the network level throughput, respectively. Conesponding to each of the objectives, a heuristic association scheme is designed and the timeline allocations of the CHs are calculated. Numerical results based on computer simulation demonstrate that the proposed schemes achieve close-to-optimum performance.</p> <p>In the second part of the thesis we study the end-to-end transmission delay for traffic at different levels of a WSN with the cluster tree topology. The end-to-end delay includes both local transmission delay between the sensor nodes and their directly associated CHs and inter-CH transmission delay between the forwarding CHs along the path to the sink. Given the timeline allocations of each CH for local and inter-cluster traffic transmissions, we find the distribution of the local traffic transmission delay and that of the inter-CH transmission delay. Based on these results, we then derive the distribution of the end-to end transmission delay and the packet drop rate due to excessive delay. The results provide important guidelines for allocating the CH time resources in order to achieve certain delay or packet drop rate performance. By appropriately allocating the CH time resources, it is possible that traffic traversing more hops to the sink experiences better delay performance than that traversing a fewer number of hops.</p> / Master of Applied Science (MASc)

<p>Free-Space Optical (FSO) communication systems have recently attracted considerable attention in last-mile applications. High bandwidth, unlicensed spectrum, ease of installation, and high security have made them a good candidate for high data rate transmissions. However, distance-dependent atmospheric turbulence and channel loss degrade the optical link reliability and confine FSO systems to short-haul applications. This thesis addresses innovative all-optical relaying techniques to mitigate the degrading effects of atmospheric turbulence-induced fading by relaying data from the source to the destination using intermediate terminals. The proposed techniques, optical amplify-and-forward (OAF) relaying and optical regenerate-and-forward (ORF) relaying, are deployed in multihop FSO systems to extend the maximum accessible communicating distance of high data rate wireless optical systems.<br /> In all-optical relaying techniques, photo detection is performed once at the receiver and intermediate terminals process optical field envelopes instead of optical intensities. This major difference requires a new definition of channel model for propagation of optical waves through the atmosphere. By using the developed channel model, bit error rate (BER) performance of multihop OAF FSO systems is analyzed through Monte-Carlo simulations. The simulation results indicate that OAF relaying technique mitigates the channel impairments and enhances the BER performance. By employing more relays, longer distances become accessible, however distance improvement decreases due to accumulating background noise at relays. In order to remove background noise effects, another optical relaying technique is developed. The ORF relaying technique eliminates the received background noise at each relay and significantly outperforms OAF systems. For example at high bit rate BR= 10 Gbps, using two equally-spaced OAF relays during a 3 km turbulence-free link increases the total communicating distance by about 1.11 km. Replacing OAF relays by ORF relays extends the total communicating distance to 4.48 km which is 1.66 km longer than the similar OAF FSO system. By deploying more ORF relays, even longer distances are achievable.</p> / Master of Applied Science (MASc)

<p>In this thesis an efficient approach to nonlinear non-Gaussian state estimation based on spline filtering is presented. The estimation of the conditional probability density of the unknown state can be ideally achieved through Bayes rule. However, the associated computational requirements make it impossible to implement this online filter in practice. In the general particle filtering problem, estimation accuracy increases with the number of particles at the expense of increased computational load. In this thesis, B-Spline interpolation is used to represent the density of the state pdf through a low order continuous polynomial. The motivation is to reduce the computational load and to improve accuracy. The motion of spline control points and corresponding coefficients is achieved through implementation of the Fokker-Planck equation, which describes the propagation of state probability density function between measurement instants. The solution of the Fokker Planck equation is achieved by calculating the state transition probability matrix. The state transition matrix is calculated using Dirac Feynman approximation. This filter is applicable for a general state estimation problem as no assumptions are made about the underlying probability density. Finally, simulation results are presented to demonstrate the effectiveness of the proposed algorithm.</p> / Master of Applied Science (MASc)

<p>Optical flow is a well known technique for the measurement of motion in images. Although it has many applications, calculating the optical flow remains computationally expensive and challenging to use in time-critical tasks. This thesis describes an accelerated approach to optical flow computation using foveation and parallel processing on a Graphics Processing Unit (GPU). Foveation reduces the amount of image data to process by mimicking the variable resolution structure of the human visual system. The resulting image data is processed in parallel on a 240 processor GPU to achieve high frame rates on high resolution images. The newly introduced Compute Unified Device Architecture (CUDA) framework is utilized to create an efficient mapping of optical flow and foveation algorithms to the GPU. <br /> The performance and error of the algorithm is characterized using synthetic and real data. The non-foveated optical flow algorithm is found to perform up to 100× faster than a CPU implementation. Foveated optical flow is found to give an additional performance gain of up to 27× over non-foveated optical flow with a corresponding increase in angular error. The results are shown to match or outperform FPGA and non-CUDA GPU implementations. Finally, the application of the described system to real-time control of a robot arm is demonstrated.</p> / Master of Applied Science (MASc)

<p>Sequentially plasma activated bonding (SPAB) of silicon wafers has been investigated to facilitate chemical free, room temperature and spontaneous bonding required for integration of nanostructure on the wafer scale. The SPAB consists of surface activation using reactive ion etching (RIE) plasma followed by microwave (MW) radicals. The drop shape analysis and atomic force microscopy (AFM) results show that O2 RIE plasma is the most efficient in removing surface contaminations while keeping smooth surfaces. On the other hand, MW N2 radicals offer highly reactive, smooth and hydrophilic surfaces. These highly reactive, smooth and hydrophilic surfaces allow strong and spontaneous bonding of silicon/silicon at room temperature. Electrical characteristics show that the current transportation across the nano-bonded interface is dependent on plasma parameters. The infrared images show that plasma induced voids' nucleation at the bonded interface is dominated by O2 RIE power over O2 RIE activation time. The bonding strength achieved at room temperature in SPAB is about 30 times higher than that in hydrophilic bonding.<br /> In order to explore the reliability of SPAB at high temperature, the bonded wafers are annealed from 200 to 900°C. The thermal induced voids' nucleation occurred preferentially at the plasma induced defect sites. The nucleation of void density is quantitatively determined and explained using high resolution transmission electron microscopy (HRTEM) observations. The electron energy loss spectroscopy results reveal the existence of silicon dioxide at the bonded interface. The reduction in bonding strength after annealing at high temperature is correlated to the increase in void density. The plasma induced defect sites such as nanopores and craters are identified using an AFM. The porous surface allows easy removal of interfacial water and spontaneous covalent bonding at room temperature. The HRTEM results confirm nanometer scale bonding which is needed for the integration of nanostructures. Based on the results, a bonding mechanism of SPAB is presented. <br /> In order to expand the applicability of SPAB for diverse materials, a novel hybrid plasma bonding (HPB) process is developed to achieve void-free and strong silicon/glass and germanium/glass bonding at low temperature. The HPB combines sequential plasma activation with anodic bonding process. Void-free interface with high bonding strength is observed both for silicon/glass and germanium/glass at 200oe. The bonding strength of the silicon/glass and germanium/glass in the HPB at 2000e is 30 MPa and 9.1 MPa, respectively. The improved characteristic behavior of the interface in the HPB is attributed to higher hydrophilicity and smooth surfaces of silicon, glass and germanium after sequential plasma activation and high electrostatic force associated with anodic bonding. Based on the results, a bonding mechanism of HPB is discussed. <br /> The chemical free strong bonding of silicon/silicon in SP AB at room temperature and void-free strong bonding of silicon/glass and germanium/glass in HPB at low temperature can be applied in spontaneous integration of nanostructures on the wafer scale.</p> / Master of Applied Science (MASc)

<p>The multiple hypotheses tracker (MHT) is an optimal tracking method due to the enumeration of all possible measurement-to-track associations. However, its practical implementation is limited by the NP-hard nature of this enumeration. To bound the computational complexity, some means of limiting the number of possible associations is required. Typical solutions include the interposition of rules to guide the pruning and merging of tracks. Other proposals have shown that the performance of a tracker, MHT or not, can be improved using feature information (e.g., signal strength, size, type) in addition to kinematic data. The inclusion of feature information allows for the discrimination to further gate the data associations. However, in most tracking systems, the schemes to manage the data association problem are extraneous to the Bayesian framework of the MHT. Further, the extraction of features from the raw sensor data is typically independent of the subsequent association and filtering stages. The features are then used in either an ad hoc way or are they are fused with the MHT tracker; they are not used intrinsically within MHT framework. In this thesis, a new approach whereby there is an intrinsic interaction between feature extraction and the MHT is presented. The measure of the quality of feature extraction is input into measurement-to-track association while the prediction step feeds back information to be used in the next round of feature extraction to increase the information available a priori. The motivation for this forward and backward interaction between feature extraction and tracking is to improve the performance in both steps. This approach allows for a more rational partitioning of the feature space, removing unlikely features from. the assignment problem. In addition, a track-specific detection probability becomes available to the prior. This probability significantly improves the coasting behavior when measurements are not available for track continuation. Simulation results demonstrate the benefits of the proposed approach.</p> / Master of Applied Science (MASc)

<p>An improved Perfectly Matched Layer (PML) boundary condition is introduced that addresses the previously reported instabilities. A PML for acoustic waves is derived by closely following Bérenger's derivation of a PML for electromagnetic waves. A new matching condition is developed to relate the velocity and stress loss-coefficients similar to the matching condition defined for electromagnetic waves.<br /> Whereas, the spatial and temporal derivatives are related by simple scalars in Maxwell's equations, elastodynamic equations describing waves in piezoelectric materials require the use of tensor quantities whose general forms are material dependent. <br /> In practice, SAW generation is often also accompanied by some small creation of SAWs, which act as parasitic waves. It is thus desired to remove the reflection of these waves from the bottom, in both physical SAW devices and in modeling.</p> / Master of Applied Science (MASc)

<p>This thesis is concerned with interpolation along the Z-axis for application in medical imaging and increasing out-of plane resolution of 3-D medical image sets. Interpolation along the Z-axis is an essential task in clinical studies for better diagnosis and analysis of body organs and their functions. It is also necessary when sets of images with different out-of plane resolutions should be analyzed together.</p> <p>The first part of the thesis discusses a 3-D interpolation method based on a piece-wise autoregressive model that has been already proven to be efficient for 2-D image interpolation. The 3-D image set is modeled as a 3-D piece-wise autoregressive model and the model parameters are estimated within a cube that slides through the low resolution image set.</p> <p>The major part of this thesis is devoted to a new interpolation algorithm, called contextbased 3-D interpolation. The proposed method represents a new approach of aiding 3-D interpolation and improving its performance by efficient use of domain knowledge about the anatomy, orientation and imaging modalities. In the new approach a family of adaptive 3-D interpolation filters are designed and conditioned on different spatial contexts (classes of feature vectors). Training is used to incorporate the domain knowledge into the design of these interpolators. Experimental results show significant improvement of the new approach over some existing 3D interpolation techniques.</p> / Master of Applied Science (MASc)

<p>In many radar tracking systems ·with a certain pulse-repetition frequency (PRF), Doppler (or range rate) measurements are available in addition to position measurements. The extra range rate information Doppler measurements provide is able to improve the tracking performance. However, a fundamental problem associated with Pulse-Doppler radars is, especially at low PRFs, range rate ambiguity. This is because Doppler shifts in the frequency spectrum are aliased by a difference of an integer times of PRF. In this case, the observed Doppler measurement shifts from the true range rate by an unknown difference.</p> <p>In previous works, algorithms to eliminate the Doppler ambiguity based on the Chinese Remainder Theorem have been proposed for radars with multiple PRFs. Time- Frequency Analysis (TFA) using Fast Fourier Transform (FFT) can reduce the ambiguity in the frequency domain.</p> <p>In this paper, a new approach for multitarget detection and tracking with Doppler ambiguity is presented. Ambiguous Doppler measurements in addition to the position measurements are directly used in data association and tracking. To solve the Doppler ambiguity for single target tracking, three methods are proposed based on UKF, MHT and PDA, respectively. In addition, modifications to Multiple Hypothesis Tracking (MHT) and Joint Integrated Probabilistic Data Association (JIPDA) algorithms to resolve Doppler ambiguity in multitarget tracking are considered. Simulation results are preformed to demonstrate the new algorithms with tracking results analysis.</p> / Master of Applied Science (MASc)