Radio frequency interference is an ever growing problem in the wireless community. This dissertation presents methods to reduce interference for vehicular multi-antenna devices. This document is organized into two parts: the main chapters and the appendices. The main chapters present research conducted primarily by the author. These deserve the reader's primary attention. The appendices showcase contributions made by the author serving in a supporting role to projects led by others and/or do not fit the vehicular theme. These should receive secondary attention. The main chapter contributions are summarized as follows. A device was created that provides over 105 dB of transmit to receive isolation in a full duplex printed circuit board radio. This technology can improve the effective range of vehicular radar systems and increase the bandwidth of full duplex communication schemes for vehicles. The technologies involved are compatible with existing circuit board topologies and are mindful of the size and weight requirements for vehicular use. This isolation performance pushes the state of the art for printed circuit board designs and provides greater capability for these kinds of devices. Recent system on chip computing architectures are opening new pathways for integrating phased array technologies into a single chip. The computer engineering required to configure these devices is beyond the capabilities of many vehicle systems engineers, inviting the author to use one to implement a 16 antenna adaptive beamformer for GPS. The adaptive beamformer can combat multipath bounces and malicious spoofing from ground sources. The high rate analog conversion architecture eliminates the local oscillator distribution to simplify the analog front end to an active antenna. This allows vehicular phased arrays to use smaller footprints and suggests that multi-antenna beamforming devices may be easier to deploy on small to midsized vehicles. Bench tests of the beamformer indicate it can adapt to the environment and increase the received signal strength suggesting it can improve GPS quality for active deployments. The bank of subspace projection beamformers is a popular choice for mitigating interference in digital phased array receivers. A method was discovered that maps that matrix operator into a circuit topology that is simple to implement in an analog circuit and cancels across the entire bandwidth simultaneously. This can offload computational interference mitigation from the signal processor while still allowing secondary multi-pixel digital beamforming downstream. This beamformer was analytically connected to the body of phased array literature and studied to estimate practical error bounds and design methods of calibration.

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Recently, the more widespread use of three-dimensional (3-D) imaging modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), and ultrasound (US) have generated a massive amount of volumetric data. These have provided an impetus to the development of other applications, in particular telemedicine and teleradiology. In these fields, medical image compression is important since both efficient storage and transmission of data through high-bandwidth digital communication lines are of crucial importance. Despite their advantages, most 3-D medical imaging algorithms are computationally intensive with matrix transformation as the most fundamental operation involved in the transform-based methods. Therefore, there is a real need for high-performance systems, whilst keeping architectures exible to allow for quick upgradeability with real-time applications. Moreover, in order to obtain efficient solutions for large medical volumes data, an efficient implementation of these operations is of significant importance. Reconfigurable hardware, in the form of field programmable gate arrays (FPGAs) has been proposed as viable system building block in the construction of high-performance systems at an economical price. Consequently, FPGAs seem an ideal candidate to harness and exploit their inherent advantages such as massive parallelism capabilities, multimillion gate counts, and special low-power packages. The key achievements of the work presented in this thesis are summarised as follows. Two architectures for 3-D Haar wavelet transform (HWT) have been proposed based on transpose-based computation and partial reconfiguration suitable for 3-D medical imaging applications. These applications require continuous hardware servicing, and as a result dynamic partial reconfiguration (DPR) has been introduced. Comparative study for both non-partial and partial reconfiguration implementation has shown that DPR offers many advantages and leads to a compelling solution for implementing computationally intensive applications such as 3-D medical image compression. Using DPR, several large systems are mapped to small hardware resources, and the area, power consumption as well as maximum frequency are optimised and improved. Moreover, an FPGA-based architecture of the finite Radon transform (FRAT)with three design strategies has been proposed: direct implementation of pseudo-code with a sequential or pipelined description, and block random access memory (BRAM)- based method. An analysis with various medical imaging modalities has been carried out. Results obtained for image de-noising implementation using FRAT exhibits promising results in reducing Gaussian white noise in medical images. In terms of hardware implementation, promising trade-offs on maximum frequency, throughput and area are also achieved. Furthermore, a novel hardware implementation of 3-D medical image compression system with context-based adaptive variable length coding (CAVLC) has been proposed. An evaluation of the 3-D integer transform (IT) and the discrete wavelet transform (DWT) with lifting scheme (LS) for transform blocks reveal that 3-D IT demonstrates better computational complexity than the 3-D DWT, whilst the 3-D DWT with LS exhibits a lossless compression that is significantly useful for medical image compression. Additionally, an architecture of CAVLC that is capable of compressing high-definition (HD) images in real-time without any buffer between the quantiser and the entropy coder is proposed. Through a judicious parallelisation, promising results have been obtained with limited resources. In summary, this research is tackling the issues of massive 3-D medical volumes data that requires compression as well as hardware implementation to accelerate the slowest operations in the system. Results obtained also reveal a significant achievement in terms of the architecture efficiency and applications performance.

Deep tectonic tremor has been observed in major subduction zones, strike-slip faults, inland faulting systems, and arc-continent collision environments around the Pacific Rim. However, detailed space-time evolution of its source locations remains enigmatic because of difficulties in detecting and locating tremor accurately. In 2011, we installed two dense, small-aperture seismic arrays aiming to detect ambient tremor source beneath southern Central Range in Taiwan. We recorded continuous waveforms for a total of 134 days, including tremor triggered by the great 2011 Mw9.0 Tohoku earthquake. We use the broadband frequency-wavenumber beamforming and the moving-window grid-search methods to compute array parameters for detecting seismic signals. The obtained array parameters closely match both relocated local earthquakes and triggered tremor bursts located by an envelope cross-correlations method, indicating the robustness of our array technique. We identify tremor signals with coherent waveforms and deep incidence angles and detect tremor for 44 days among the 134-day study period. The total duration is 1,481-minute, which is 3-6 times more than that detected by the envelope cross-correlations method. In some cases, we observe rapid tremor migration with a speed at the order of 40-50 km/hour that is similar to the speed of fast tremor migration along-dip on narrow streaks in Japan and Cascadia. Our results suggest that dense array techniques are capable of capturing detailed spatiotemporal evolutions of tremor behaviors in southern Taiwan.

Longitudinal optical binding refers to the light induced self organisation of micro particles in one dimension. In this thesis I will present experimental and theoretical studies of the separation between two dielectric spheres in a counter-propagating (CP) geometry. I will explore the bistable nature of the bound sphere separation and its dependency on the refractive index mismatch between the spheres and the host medium, with an emphasis on the fibre separation. The physical under pining principle of longitudinal optical binding in the Mie regime is the refocusing effect of the light field from one sphere to its nearest neighbour. In a second set of experiments I developed means to visualise the field intensity distribution responsible for optical binding using two-photon fluorescence imaging from fluorescein added to the host medium. The experimental intensity distributions are compared to theoretical predictions and provide an in situ method to observe the binding process in real time. This coupling via the refocused light fields between the spheres is in detailed investigated experimentally and theoretically, in particular I present data and analysis on the correlated behaviour of the micro spheres in the presence of noise. The measurement of the decay times of the correlation functions of the modes of the optically bound array provides a methodology for determining the optical restoring forces acting in optical binding. Interestingly micro devices can be initiated by means of the light-matter interaction. Light induced forces and torques are exerted on such micro-objects that are then driven by the optical gradient or scattering force. I have experimentally investigate how the driving light interacts with and diffracts from the motor, utilising two-photon imaging. The micromotor rotation rate dependence on the light field parameters is explored and theoretically modelled. The results presented will show that the model can be used to optimise the system geometry and the micromotor.

This thesis summarizes ongoing work to develop low-cost, wireless, resonant sensor array that can be used to monitor corrosion in infrastructure systems. A magnetically coupled sensor array is presented and analyzed using circuit model. The array acts as a magneto-inductive waveguide and the impedance discontinuities caused by corrosion (or other defects) lead to reflection. The relationship between the relative position of defects and pass band characteristics is investigated, providing a technique to determine the location of targets. A configuration for increased sensitivity and a method for defect localization are presented. / text

Many advances in technology ranging from biology and medicine through engineering and computer science to fundamental physics and chemistry depend upon the capability to control the fabrication of materials and devices at the submicron scale. Quantum mechanical effects become increasingly important to atomic and molecular interactions as the distances between neighbors decrease. These effects will provide materials and device designers with additional flexibility to establish properties of the designers choice, but the cost of this additional flexibility must be paid in the complexity of nonlinearities entering the interactions and the design process. The work presented here has provided several early results on three such interactions among closely-spaced submicron material structures: 1) the properties of superconductivity have been studied, 2) the properties of ferromagnetism have been studied, and 3) the interactions between superconductivity and ferromagnetism have been studied. Since our work was published, there has been considerable interest in all three of these wide-open areas and hundreds or thousands of additional results are now in the literature. We have used standard methods from the semiconductor industry as well as innovative methods to fabricate micron and submicron devices for observation. Standard optical lithography and standard electron beam lithography have been implemented to shape micron and submicron structures, respectively. Additionally, a laser interferometric lithography method has been invented and used to shape submicron structures. The materials used were vanadium, niobium, nickel, and/or permalloy. We have utilized SQUID magnetometry and Hall effect magnetometry to observe the properties of superconductor structures and superconductorferromagnetic mixed systems. We have used SQUID magnetometry and ferromagnetic resonance to observe the physical properties of ferromagnetic structures and the interactions between adjacent structures. Using these materials and methods we have discovered an unusual paramagnetic Meissner effect in thin Nb films that exists at igh-applied magnetic fields. We have discovered fluxoid matching anomalies at low sample temperature. And we have discovered interactions between electron exchange and magnetic dipole forces. Additionally, we have found clear evidence to support several past hypotheses advanced by other authors.

La technologie des microarrays est une technique d’analyse d’expression génique à grande échelle qui permet d’analyser simultanément l’expression de milliers de gènes dans différentes cellules et différentes conditions physiologiques, pathologiques ou toxicologiques (Shena et al, 2000). Dans notre étude nous avons employé cette technique pour mieux comprendre deux pathologies thyroïdiennes: les carcinomes papillaires (PTC) et les adénomes autonomes hyperfonctionnels. L’étude des profils d’expression génique de 9 carcinomes papillaires thyroïdiens sporadiques et de 13 carcinomes papillaires post-Chernobyl a été effectuée en utilisant les lames commerciales de Perkin-Elmer (comportant 2400 cDNA) et en les comparant à leurs tissus normaux adjacents. Les PTC post-Tchernobyl constituent une population de cancers à cause bien définie puisqu’ils sont directement reliés à l’exposition du même agent mutagène, pendant une même période. L’étude des profils d’expression indique qu’il n’y a pas de signature génique spécifique permettant de distinguer les carcinomes papillaires sporadiques des post-Tchernobyl. La comparaison de ces profils d’expression à celui obtenu avec 13 adénomes autonomes a permis de mettre en évidence une signature de 6 gènes (créatine kinase B, annexine A1, clusterine, métallothionéine 1x, Fc fragment of IgG binding protein et tissue inhibitor of metalloproteinase 1) séparant les carcinomes papillaires malins des adénomes autonomes bénins. Nous avons également analysé l’expression génique sur des mélanges de tumeurs et de leurs contrôles respectifs sur des lames à 17000 cDNA fabriquées au MAF (VIB Microarray Facility, Leuven). Un mélange de 14 cancers papillaires sporadiques, un mélange de 20 cancers papillaires provenant de la région de Tchernobyl et un mélange de 5 adénomes autonomes ont été analysés par microarray et comparés aux études existantes comme celles effectuées sur les lames Perkin-Elmer ou par d’autres groupes (Huang et al, 2001 ; Wasenius et al, 2003 ; Jarzab et al, 2005 ; Eszlinger et al, 2004). De ces données microarray ont résulté des listes de gènes sur- et sous-exprimés dans les tumeurs comparées à leurs tissus normaux adjacents. Plusieurs gènes différentiellement exprimés ont déjà été confirmés dans différentes études réalisées aussi bien dans notre laboratoire que dans d’autres. Nous avons confirmé la modulation de plusieurs gènes intéressants par RT-PCR en temps réel (Taqman) ainsi que certaines modulations au niveau protéique (par Western Blot ou immunohistochimie). L’étude immunohistochimique nous a donné également des informations sur la distribution cellulaire et tissulaire de ces protéines. La modulation d’expression génique dans ces tumeurs reflète des caractéristiques physiopathologiques connues (comme l’hyperactivité fonctionnelle, la faible augmentation de l’AMPc ou encore la diminution de l’apoptose dans les adénomes autonomes et la dédifférenciation ou l’invasivité dans les carcinomes papillaires), mais elle nous a également permis d’identifier des caractéristiques physiopathologiques jusqu’ici encore inconnues de ces tumeurs (comme la surexpression de la N-cadhérine et la diminution de la cavéoline1, deux marqueurs présumés de malignité, dans les tumeurs bénignes et un changement de population cellulaire aussi bien dans les adénomes autonomes que dans les carcinomes papillaires). Ces études nous ont donc permis de définir des gènes potentiellement importants dans la pathologie des différentes tumeurs étudiées, mais également des nouveaux marqueurs diagnostiques potentiels. Ainsi, l’étude immunohistochimique sur des tissu-arrays nous a permis de confirmer la surexpression de l’annexine A1 dans les carcinomes papillaires et de la créatine kinase B dans les adénomes autonomes et pas dans les autres tumeurs thyroïdiennes étudiées. L’immunomarquage de ces protéines nous a également aidé à définir la malignité d’une série d’adénomes atypiques. L’annexine A1 est un marqueur potentiel particulièrement intéressant car cette protéine n’est fortement exprimée que dans les carcinomes papillaires. Une hypothèse, encore à confirmer, sur sa fonction dans cette pathologie est décrite dans ce travail. Finalement, nous avons émis une hypothèse expliquant la raison pour laquelle les réarrangements Ret/PTC mènent à la formation de carcinomes papillaires, tandis qu’une mutation activatrice de Ras, l’effecteur directe du récepteur à activité tyrosine kinase Ret, mène à la formation de tumeurs folliculaires.