International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper will discuss the design and performance of card level telemetry receivers and combiners. This will include products that have been designed to operate in compact computer controlled environments such as VME chassis, VXI chassis and personal computers using ISA buses. The paper will discuss design considerations required to overcome limitation of this environment such as noise and space. The paper will also discuss the performance of a telemetry receiver and combiner in this environment. This will include performance test results such as bit error rate test, phase noise measurements and combiner improvement measurements. Finally, the paper will discuss typical applications of card level telemetry receivers and combiners.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Acquisition based on Fast Fourier Transform (FFT) can acquire Pseudo-random code phase quickly and improve the performance of the satellite navigation receivers. In the paper Real-time receiver adopts the FPGA to realize the function of FFT and uses DSP processor to control the implementation process of Acquisition. For increasing the sensitivity of Acquisition incoherent accumulation were used in the process. Also, in the paper we have discussed the process method for decreasing the negative influence of signal power changes and carrier's Doppler frequency.

Master of Science / Department of Electrical Engineering / William Kuhn / Q-enhanced Filters have been researched extensively, but have not been often implemented into receiver architectures due to inherent challenges in the design and stability of these filters. However, recent works have successfully addressed Q-enhanced filter designs which are viable for receiver implementation with tuning algorithms to achieve temperature stability. This work continues these efforts with the redesign of a Two-Pole Q-Enhanced Band-Pass filter tested at narrower fractional bandwidths than previous work of less than one percent and considers potential significant improvements in receiver performance using this filer. The Q-enhanced filter redesign ports the existing filter to a new integrated circuit technology which performs better at higher frequencies. The redesign in particular addresses problems in the previous design. The frequency divider design is modified, resistance tuning is added, and additional modifications to the overall filter functionality are implemented. General problems in obtaining an ideal passband shape by eliminating unwanted coupling are addressed. The supporting software for the tuning algorithm is modified to use analog controls and shown to achieve further narrowed bandwidths of 5 MHz and 2.5 MHz at center frequencies of 500 MHz, which are demonstrated to be temperature stable. Future software modifications are described to prepare the existing code base for the new filter design. Potential applications for a Q-enhanced filter include improving the performance of receiver designs. One of the most important performance parameters of a receiver is its spurious response rejection. To explore this behavior, an automated test system is developed to characterize receivers, and four receivers are tested. The test results are presented in a novel graphical display, which is used to evaluate receiver performance and compare receivers. These results motivated the development of a potential modified superheterodyne receiver architecture using the Q-enhanced filter as an image filter and an IF filter. The viability of this receiver design is tested and shown to provide significant improvements to receiver’s spurious rejection response.

During the thesis, a two-staged analog baseband circuit incorporating a passive analog filter and a wideband voltage amplifier were successfully designed, implemented in an IC mask layout in a 65nm CMOS technology, and joined with a previously designed analog front-end design to form a wideband observation receiver. The baseband circuit is capable of receiving an IF bandwidth up to 990MHz produced by the analog front-end using low-side injection. The final circuit shows high IMD3 of at least 90 dBc. The voltage amplifier delivers a voltage amplification of 15 dB with around 0.08 dB amplitude precision over the bandwidth, while the passive filter is capable of a passband amplitude precision of 0.67 dB over the bandwidth, while effectively suppress signal images created by the mixer with at least 60 dBc. Both stages were realized in an IC mask layout, in addition, the filter layout were simulated using an EM simulator.

Este trabalho dimensionou um receptor de cavidade para uso como reator químico de um ciclo de conversão de energia solar para energia química. O vetor energético proposto é o hidrogênio. Isso implica que a energia solar é concentrada em um dispositivo que absorve a radiação térmica e a transforma em energia térmica para ativar uma reação química endotérmica. Essa reação transforma o calor útil em gás hidrogênio, que por sua vez pode ser utilizado posteriormente para geração de outras formas de energia. O primeiro passo foi levantar os pares metal/óxido estudados na literatura, cuja finalidade é ativar um ciclo termoquímico que possibilite produção de hidrogênio. Esses pares foram comparados com base em quatro parâmetros, cuja importância determina o dimensionamento de um receptor de cavidade. São eles: temperatura da reação; estado físico de reagentes e produtos; desgaste do material em ciclos; taxa de reação de hidrólise e outros aspectos. O par escolhido com a melhor avaliação no conjunto dos parâmetros foi o tungstênio e o trióxido de tungstênio (W/WO3). Com base na literatura, foi determinado um reator padrão, cujas características foram analisadas e suas consequências no funcionamento do receptor de cavidade. Com essa análise, determinaram-se os principais parâmetros de projeto, ou seja, a abertura da cavidade, a transmissividade da janela, e as dimensões da cavidade. Com base nos resultados anteriores, estabeleceu-se um modelo de dimensionamento do sistema de conversão de energia solar em energia útil para um processo químico. Ao se analisar um perfil de concentração de energia solar, calculou-se as eficiências de absorção e de perdas do receptor, em função da área de abertura de um campo de coleta de energia solar e da radiação solar disponível. Esse método pode ser empregado em conjunto com metodologias consagradas e dados de previsão de disponibilidade solar para estudos de concentradores de sistemas de produção de hidrogênio a partir de ciclos termoquímicos. / This work aimed to design a cavity receptor for purpose of chemical reactor for cycles of energy conversion of solar energy to chemical energy. The proposed chemical agent is hydrogen gas. Solar energy is concentrated in a device that absorbs thermal radiation, transforming it in thermal energy, used to activate chemical reactions. This reaction transforms the heat in hydrogen gas and the last, in its turn, can be used to generate other forms of energy. The first step oh this work was an assessment of metal/oxides pairs studied in literature, which can be used to activate thermochemical cycles for hydrogen production. These pairs were compared based in four parameters, important to cavity receptor design: reaction temperature, physical state of the reactants and products, material resistance to several cycles; hydrolysis reaction rate and other aspects. The chosen pair, rated as the higher average in all parameters, was the pair tungsten and tungsten trioxide. (W/WO3). Based in the literature, it was determined a standard reactor, which was studied regarding cavity reactor performance. By such analysis, it was possible to determine the main design parameters, therefore, cavity aperture, window transmissivity, and the cavity geometric dimensions. The results allowed to establish a mathematical model in which solar energy can be converted in useful energy for chemical processes, inside a cavity receptor. Given a profile of solar energy concentration, it was calculated absorption and energy lost efficiencies, related to a solar concentration field and radiation available. This method can be used in tandem with available methodologies and data of solar predictions for hydrogen production by concentration systems via thermochemical cycles.

In this dissertation, I use seismic imaging techniques to constrain the physical state of the upper mantle beneath regions of young oceanic lithosphere. Mantle convection is investigated beneath the Galápagos Archipelago and then beneath the Juan de Fuca (JdF) plate, with a focus on the JdF and Gorda Ridges before turning to the off-axis asthenosphere. In the Galápagos Archipelago, S-to-p receiver functions reveal a discontinuity in seismic velocity that is attributed to the dehydration of the upper mantle. The depth at which dehydration occurs is shown to be consistent with prior constraints on mantle temperature. A comparison between results from receiver functions, seismic tomography and petrology shows that mantle upwelling and melt generation occur shallower than the depth of the discontinuity, despite the expectation of high viscosities in the dehydrated layer. Beneath the JdF and Gorda Ridge, low Vs anomalies are too large to be explained by the cooling of the lithosphere and are attributed to partial melt. The asymmetry, large Vs gradients, and sinuosity of the anomalies beneath the JdF Ridge are consistent with models of buoyancy-driven upwelling. However, deformation zone processes appear to dominate mantle flow over seafloor spreading beneath the Explorer and Gorda diffuse plate boundaries. Finally, S-to-p receiver functions reveal a seismic discontinuity beneath the JdF plate that can only be attributed to seismic anisotropy. Synthesis of the receiver function results with prior SKS splitting results requires heterogeneous anisotropy between the crust and the discontinuity. Models of anisotropy feature increasing anisotropy before the decrease at the discontinuity, but well below the base of the lithosphere, and a clockwise rotation of the fast direction with increasing depth. In these results and even in the SKS splitting results, additional driving mechanisms for mantle flow such as density or pressure anomalies are required.

This thesis describes the work undertaken in producing the passive radio-frequency section of a heterodyne receiver for use on the United Kingdom Infra-Red Telescope at signal frequencies in the 200-300 GHz range. This is a Quasi-Optical system, comprised of a Martin-Puplet polarising interferometer employed as a diplexer and the lenses and feed horns by which the diplexer was coupled to the telescope, local oscillator, and mixer. The Gaussian beam-mode approach was employed to develop a theoretical basis for understanding the operation of such a system upon coherent paraxial beams. Quasi-Optical systems were then designed and their performance predicted by the application of this extension of Gaussian optics. Two such systems were constructed and their performance determined by laboratory measurements to be as predicted. One of these systems was then installed on the telescope where it was shown to function as designed. As part of the calibration and test routine on the telescope a number of astronomical measurements were made, including a determination of the apparent temperatures of the planets Jupiter and Saturn by a method different to that employed for results previously published. The Quasi-Optical receiver was successfully calibrated and commissioned as a common-user instrument. As such it will continue to be used in a variety of astronomical research programs undertaken by various groups.

Doctor of Philosophy / Department of Statistics / Wei-Wen Hsu / The classification methods based on a linear combination of multiple biomarkers have been widely used to improve the accuracy in disease screening and diagnosis. However, it is seldom to include covariates such as gender and age at diagnosis into these classification procedures. It is known that biomarkers or patient outcomes are often associated with some covariates in practice, therefore the inclusion of covariates may further improve the power of prediction as well as the classification accuracy. In this study, we focus on the classification methods for multiple biomarkers adjusting for covariates. First, we proposed a covariate-adjusted classification model for multiple cross-sectional biomarkers. Technically, it is a two-stage method with a parametric or non-parametric approach to combine biomarkers first, and then incorporating covariates with the use of the maximum rank correlation estimators. Specifically, these parameter coefficients associated with covariates can be estimated by maximizing the area under the receiver operating characteristic (ROC) curve. The asymptotic properties of these estimators in the model are also discussed. An intensive simulation study is conducted to evaluate the performance of this proposed method in finite sample sizes. The data of colorectal cancer and pancreatic cancer are used to illustrate the proposed methodology for multiple cross-sectional biomarkers. We further extend our classification method to longitudinal biomarkers. With the use of a natural cubic spline basis, each subject's longitudinal biomarker profile can be characterized by spline coefficients with a significant reduction in the dimension of data. Specifically, the maximum reduction can be achieved by controlling the number of knots or degrees of freedom in the spline approach, and its coefficients can be obtained by the ordinary least squares method. We consider each spline coefficient as ``biomarker'' in our previous method, then the optimal linear combination of those spline coefficients can be acquired using Stepwise method without any distributional assumption. Afterward, covariates are included by maximizing the corresponding AUC as the second stage. The proposed method is applied to the longitudinal data of Alzheimer's disease and the primary biliary cirrhosis data for illustration. We conduct a simulation study to assess the finite-sample performance of the proposed method for longitudinal biomarkers.

A doença periodontal (DP) compreende um grupo de lesões que afeta os tecidos periodontais de proteção e de suporte e pode acarretar na perda dentária. Interações entre patógenos microbianos e vários sistemas desempenham um papel crítico no desenvolvimento e progressão da DP via liberação de vários mediadores inflamatórios e imunológicos. Experimentos recentes de nosso grupo de pesquisa mostraram que existe a expressão de RNAm para todos os componentes do Sistema Renina-Angiotensina (SRA), presença da renina e atividade da Enzima Conversora de Angiotensina (ECA) em tecido gengival de ratos e que o losartan inibe a perda óssea no modelo de DP induzida experimentalmente em ratos. Portanto, o presente trabalho propõe-se a investigar os mecanismos pelos quais o losartan (antagonista do receptor AT1) possui efeitos anti-inflamatórios no modelo da DP induzida experimentalmente em ratos. Para tanto, foi utilizado o modelo de indução da DP por colocação de ligadura ao redor do primeiro molar inferior de ratos divididos em treze grupos com 15 animais cada, que foram tratados com losartan (50 mg/kg/dia) via gavage. As técnicas utilizadas neste trabalho foram: indução da DP em ratos, a análise tomográfica da perda óssea alveolar (MicroCT), análise 2D com uso de software específico (ImageJ), RT-PCR e análise histológica do tecido periodontal. Após a coleta, os dados foram devidamente analisados por meio de gráficos e tabelas, sendo utilizado ANOVA, seguida de um pós-teste para determinar a significância da diferença entre os grupos dentro de um mesmo ensaio. Foi adotado nível de significância de 5%. O losartan foi capaz de atuar no aumento da expressão de enzimas, citocinas, quimiocinas e receptores, tais como: AT2, MAS, AT1a, AT1b, AGT, OPG, ALP, PHEX, RUNX2, BGLAP, IL-18, IL-21 e MMPs. Além disso, promoveu a diminuição de citocinas pró-inflamatórias como IL-6, IL-10 e INF, indicando assim seu papel anti-inflamatório, dados observados na análise molecular do tecido gengival e ósseo. Macroscopicamente foi confirmado que o tratamento com losartan foi capaz de atenuar a perda óssea. Os achados histológicos corroboram com as análises de MicroCT e RT-PCR. Concluiu-se então que o losartan possui efeito protetor na preservação do periodonto em animais submetidos à DP devido à diminuição de moléculas envolvidas na inflamação. / Periodontal disease (PD) comprises a group of lesions that affect the periodontal tissues of protection and support and can lead to tooth loss. Interactions between microbial pathogens and various systems play a critical role in the development and progression of PD through release of various inflammatory and immunological mediators. Recent experiments from our research group have shown that mRNA expression exists for all components of the Renin-Angiotensin System (RAS), presence of renin and Angiotensin Converting Enzyme (ACE) activity in rat gingival tissue and that losartan inhibits the bone loss in the experimentally induced PD model in rats. Therefore, the present work aims to investigate the mechanisms by which losartan (AT1 receptor antagonist) has anti-inflammatory effects in the PD model induced experimentally in rats. For this, the PD induction model was used by placing ligation around the lower first molar of rats divided into thirteen groups with 15 animals each, which were treated with losartan (50mg / kg / day) via gavage. The techniques used in this work were: induction of PD in rats, tomographic analysis of alveolar bone loss (MicroCT), 2D analysis using specific software (ImageJ), RT-PCR and histological analysis of periodontal tissue. After the data collection, the data were analyzed by means of graphs and tables, using ANOVA, followed by a post-test to determine the significance of the difference between groups within the same trial. A significance level of 5% was adopted. Losartan was able to increase the expression of enzymes, cytokines, chemokines and receptors, such as AT2, MAS, AT1a, AT1b, AGT, OPG, ALP, PHEX, RUNX2, BGLAP, IL-18, IL-21 and MMPs. In addition, it promoted the reduction of proinflammatory cytokines such as IL-6, IL-10 and INF, thus indicating its anti-inflammatory role, data observed in the molecular analysis of gingival and bone tissue. Macroscopically it was confirmed that treatment with losartan was able to attenuate bone loss. Histological findings corroborate with MicroCT and RT-PCR analyzes. It was concluded that losartan has a protective effect on the preservation of the periodontium in animals submitted to PD due to the decrease of the molecules involved in the inflammation.

The complementary advantages of GPS and INS have been the principle driving factor to integrate these two navigation systems as an integrated GPS/INS system in various architectural forms to provide robust positioning. Although the loosely coupled and tightly coupled GPS/INS systems have been in existence for over a decade or two and performed reasonably well, nevertheless, the tracking performance was still a concern in non-benign environments such as dynamic scenarios, indoor environments, urban areas, under foliages etc., where the GPS tracking loops lose lock due to the signals being weak, subjected to excessive dynamics or completely blocked. The motivation of this research, therefore, was to address these limitations with an integrated GPS/Pseudolite/INS system using ultra-tight integration architecture. The main research contributions are summarised as below: (a) The performance of the tracking loops in dynamic scenarios were analysed in detail with both conventional and ultra-tight software receivers. The stochastic modelling of the INS-derived Doppler is of utmost importantance in enhancing the benefits of ultra-tight integration, and therefore, two popular stochastic techniques??? Gauss Markov (GM) and Autoregressive (AR), were investigated to model the Doppler signal. The simulation results demonstrate that the AR method is capable of producing better accuracies and is more efficient. The algorithms to determine the AR parameters (order and coefficients) were also provided. (b) The various mathematical relationships that elicit the understanding of the ultra-tightly integrated system were derived in detail. The Kalman filter design and its implementation were also provided. Various simulation and real-time experiments were conducted to study the performance of the filter, and the results confirm the underlying assumptions in the theoretical analyses and the mathematical derivations. Covariance analysis was also performed to study the convergence and stability effects of the filter. (c) Interpolator design using signal processing techniques were proposed to increase the sampling rate of the INS-derived Doppler. To efficiently realise the interpolator transfer function, two optimal techniques were investigated ??? Polyphase and Cascaded Integrator Comb (CIC), and our results show that CIC was more efficient than polyphase in accuracy and real-time implementations. (d) The integration of Pseudolites (PL) with INS in ultra-tight configuration was analysed for an indoor environment. The acquisition and tracking performances of ???Pseudolites-only??? and ???Pseudolite/INS??? modes were compared to study the impact of the inertial signals aiding. The results demonstrate that aiding of the inertial signals with the baseband loops (acquisition and tracking) improve the overall tracking performance. An overview on the effects of the pseudolite signal propagation is also given. (e) Simulation and real-time experiments have been conducted to evaluate the proposed algorithms and the overall design of the ultra-tightly integrated system. A comparison was also done between GPS/PL/INS and GPS/INS integrated systems to study the potential advantages of the pseudolite integration. The details of the field experiment are provided. The data from a real-time experiment was processed to further evaluate the robustness of the system. The results confirm that the developed mathematical models and algorithms are correct.