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Yes / This paper presents empirical results of an innovative beam scanning leaky-wave antenna (LWA) which enables scanning over a wide angle from -35o to +34.5o between 57 GHz and 62 GHz, with broadside radiation centered at 60 GHz. The proposed LWA design is based on composite right/left-handed transmission-line (CRLH-TL) concept. The single layer antenna structure includes a matrix of 3×9 square slots that is printed on top of the dielectric substrate; and printed on the bottom ground-plane are Π and Tshaped slots that enhance the impedance bandwidth and radiation properties of the antenna. The proposed antenna structure exhibits metamaterial property. The slot matrix provides beam scanning as a function of frequency. Physical and electrical size of the antenna is 18.7×6×1.6 mm3 and 3.43􀣅􀫙×1.1􀣅􀫙×0.29􀣅􀫙, respectively; where 􀣅􀫙 is free space wavelength at 55 GHz. The antenna has a measured impedance bandwidth of 10 GHz (55 GHz to 65 GHz) or fractional bandwidth of 16.7%. Its optimum gain and efficiency are 7.8 dBi and 84.2% at 62 GHz. / Partially supported by innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET- 722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1.

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease with no known cure. Despite years of study, the etiology of SLE is still unclear. Both genetic and environmental factors have been implicated in the disease mechanisms. Gut microbiota as an environmental factor and the immune system interact to maintain tissue homeostasis, but whether this interaction is involved in the pathogenesis of SLE is unclear. In a classical model of lupus nephritis, MRL/lpr, we found decrease of Lactobacillales but increase of Lachnospiraceae in the gut microbiota. Increasing Lactobacillales in the gut by suppling a mixture of 5 Lactobacillus strains improved renal function of these mice and prolonged their survival. Further studies revealed that MRL/lpr mice possessed a "leaky" gut, which was reversed by increased Lactobacillus colonization. Inside the kidney, oral Lactobacillus treatment also skewed the Treg-Th17 balance towards a Treg phenotype. To remove Lachnospiraceae that was higher in lupus-prone mice than controls, we administered vancomycin orally to MRL/lpr mice after disease onset from 9 to 15 weeks of age. Vancomycin functions by removing Gram-positive bacteria such as Lachnospiraceae but sparing Lactobacillus spp. The treatment during active lupus reshaped the gut microbiota and significantly ameliorated systemic autoimmunity and kidney histopathology at 15 weeks of age. However, when vancomycin treatment was initiated from a very early age, the beneficial effect was not observed. Strikingly, mice given vancomycin only at the young age exhibited an even worse disease outcome. Indeed, regulatory B (Breg) cells were found to be reduced after the vancomycin treatment at young age. Importantly, adoptive transfer of Breg cells at 6-7 weeks of age rescued the beneficial effect, which indicates that Breg cells, inducible by vancomycin-sensitive gut microbiota, plays an important role in suppressing lupus disease initiation and progression. Finally, we demonstrated that bacterial DNA from the gut microbiota might be the inducer of Breg cells, as bacterial DNA administration at young age reproduced the beneficial effect seen in the Breg adoptive transfer experiment. Future studies are required to examine the clinical efficacy of targeting gut microbiota as a novel treatment against SLE. / Ph. D. / Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease with no known cure. SLE affects over 5 million people worldwide, especially women of childbearing age. Lupus nephritis is a manifestation of SLE occurring in the kidney which affects more than 50% of SLE patients and is a major cause of morbidity and mortality in SLE. Current treatments for lupus nephritis are primarily nonselective immunosuppressants, which can cause a higher incidence of severe infections. There is an imperative need for the development of new therapeutic strategies against SLE. Our research team was the first to describe the dynamics of gut microbiota in a mouse model of SLE. My dissertation research studying the role of gut microbiota in the pathogenesis of lupus-like disease in mice showed that there were both pathogenic and beneficial bacteria co-existing in the gut microbiota of lupus-prone mice. My studies revealed not only the effects of different bacteria on lupus pathogenesis, but also the immunological mechanisms by which they exert the effects. The results suggest that modulation of the gut microbiota through diet, probiotics, and/or prebiotics to selectively enhance the abundance and activity of beneficial bacteria may be an attractive strategy for disease prevention and treatment of SLE patients. Nevertheless, studies on human samples and clinical trials are required to confirm the translational application of this strategy.

A garantia de qualidade de serviço (QoS) tem-se demonstrado muito importante em aplicações em tempo real. Este trabalho apresenta um estudo sobre Mecanismos de Policiamento na tecnologia A TM, mais especificamente, sobre o funcionamento do Mecanismo Dual Leaky Bucket, utilizado pela classe de serviço VBR em rede ATM. Para este estudo foi implementado um simulador por software do mecanismo Dual Leaky Bucket. Foram analisados dois tipos de tráfegos de vídeo com compressão MPEG-2, com pouca e muita movimentação. A partir da simulação pôde-se analisar como o erro na definição de parâmetros do contrato de QoS definidos pelo usuário no estabelecimento da conexão pode levar ao aumento na taxa de perda de informações e, conseqüentemente, a degradação da qualidade necessária pela aplicação / The guarantee of quality of service (QoS) has been demonstrating very important in real time applications. This work presents a study on Policing Mechanisms in the ATM technology, more specifically, on the operation of the Dual Leaky Bucket Mechanism, used by the class of service VBR in ATM networks. For this study a Dual Leaky Bucket mechanism simulator by software was implemented. Two kinds of MPEG-2 video traffics were analyzed with a little and a lot of movement. The simulation shows how a mistake in the definition of parameters in the QoS contract, defined by user, during of the connection establishment can leads to increase of information loss rate and, consequently, the degradation of the necessary quality for the application

A garantia de qualidade de serviço (QoS) tem-se demonstrado muito importante em aplicações em tempo real. Este trabalho apresenta um estudo sobre Mecanismos de Policiamento na tecnologia A TM, mais especificamente, sobre o funcionamento do Mecanismo Dual Leaky Bucket, utilizado pela classe de serviço VBR em rede ATM. Para este estudo foi implementado um simulador por software do mecanismo Dual Leaky Bucket. Foram analisados dois tipos de tráfegos de vídeo com compressão MPEG-2, com pouca e muita movimentação. A partir da simulação pôde-se analisar como o erro na definição de parâmetros do contrato de QoS definidos pelo usuário no estabelecimento da conexão pode levar ao aumento na taxa de perda de informações e, conseqüentemente, a degradação da qualidade necessária pela aplicação / The guarantee of quality of service (QoS) has been demonstrating very important in real time applications. This work presents a study on Policing Mechanisms in the ATM technology, more specifically, on the operation of the Dual Leaky Bucket Mechanism, used by the class of service VBR in ATM networks. For this study a Dual Leaky Bucket mechanism simulator by software was implemented. Two kinds of MPEG-2 video traffics were analyzed with a little and a lot of movement. The simulation shows how a mistake in the definition of parameters in the QoS contract, defined by user, during of the connection establishment can leads to increase of information loss rate and, consequently, the degradation of the necessary quality for the application

In dieser Arbeit wird der Einsatz von Leckwellenleiter (engl. Leaky Coaxial Cable, LCX) zur funkgestützten Indoor-Positionierung in Fahrgastzellen untersucht. Mit Hilfe eines erstellten Vorgehensmodells werden zwei unterschiedliche LCX-Prototypen speziell für den Ortungseinsatz entwickelt. Hierbei wird die elektromagnetische Feldberechnung verwendet, um sowohl Leckwellenleiterstrukturen als auch deren Einsatz in einer Fahrgastzelle zu bewerten. Nach Fertigung beider Leckwellenleiter erfolgt eine messtechnische Validierung in einer vordefinierten Fahrgastzellenumgebung. Der Einsatz dieser Prototypen zur Indoor-Positionierung wird sowohl in Modell- als auch in realen Fahrzeugumgebungen, wie der AutoTram Extra Grand des Fraunhofer IVI, durchgeführt. Eine statistische Betrachtung von Messergebnissen sowie die Vorstellung eines zonenselektiven Positionierungsansatzes schließen diese Arbeit.

Film display holograms typically diffract light over a wide enough view-angle to be viewed, directly, without intervening optics. However, all holographic video displays must use optics beyond the hologram surface to overcome the challenges of small display extent and low diffraction angle by using some form of demagnification and derotation. We report a leaky mode waveguide spatial light modulator (SLM) with sufficiently high angular diffraction to obviate the need for demagnification in scanned aperture systems. This was achieved by performing a number of experiments to determine the depth of the annealed, proton-exchanged waveguide which corresponded to a maximized diffracted angle. Diffraction sweeps were recorded in excess of 19.5° for 632.8 nm light which is above the 15° required for direct view display. Moreover, we present a paired set of waveguide SLMs capable of a maximum light deflection nearing 28° for red. This deflection, which is several times larger than the angular sweep of current, state-of-the-art modulators, is made possible by the unilateral, near-collinear waveguide nature of the leaky mode interaction. The ability to double angular output in this way, which is either not possible or not practical in other SLMs, is possible in leaky mode devices, thanks to the absence of zero-order light and the lack of high-order outputs. This combined structure has angular deflection high enough to enable color holographic video monitors that do not require angular magnification. Furthermore, the low cost and high angular deflection of these devices may make it possible to make large arrays for flat-screen video holography. One improvement that could be made to the current setup would be to increase the device's diffraction efficiency. One highly influential factor of diffraction efficiency for a Bragg-regime surface acoustic wave (SAW) grating is the length of the interaction between the light and the grating. In this work, we have shown that guided light in a reverse proton exchanged (RPE) waveguide experiences less loss. This enables us to create longer devices which eventually results in devices with higher diffraction efficiency. We have also researched on LCoS SLMs and used them for two different applications: (a) photophoretic-trap volumetric displays and (b) holographic video displays. In the first case, aberrations including spherical, astigmatism, and coma can make particles to trap tighter in the focal point of the beam. Also, a new approach for holographic computations is presented which uses the electromagnetic nature of light in Maxwell Equations to find a unique phase map for every specific 3D object in space.

Film display holograms typically diffract light over a wide enough view-angle to be viewed, directly, without intervening optics. However, all holographic video displays must use optics beyond the hologram surface to overcome the challenges of small display extent and low diffraction angle by using some form of demagnification and derotation. We report a leaky mode waveg- uide spatial light modulator (SLM) with sufficiently high angular diffraction to obviate the need for demagnification in scanned aperture systems. This was achieved by performing a number of experiments to determine the depth of the annealed, proton-exchanged waveguide which corresponded to a maximized diffracted angle. Diffraction sweeps were recorded in excess of 19.5<°> for 632.8 nm light which is above the 15<°> required for direct view display.Moreover, we present a paired set of waveguide SLMs capable of a maximum light deflection nearing 28<°> for red. This deflection, which is several times larger than the angular sweep of current, state-of-the-art modulators, is made possible by the unilateral, near-collinear waveguide nature of the leaky mode interaction. The ability to double angular output in this way, which is either not possible or not practical in other SLMs, is possible in leaky mode devices, thanks to the absence of zero-order light and the lack of high-order outputs. This combined structure has angu- lar deflection high enough to enable color holographic video monitors that do not require angular magnification. Furthermore, the low cost and high angular deflection of these devices may make it possible to make large arrays for flat-screen video holography.One improvement that could be made to the current setup would be to increase the device<&trade>s diffraction efficiency. One highly influential factor of diffraction efficiency for a Bragg-regime surface acoustic wave (SAW) grating is the length of the interaction between the light and the grating. In this work, we have shown that guided light in a reverse proton exchanged (RPE) waveguide experiences less loss. This enables us to create longer devices which eventually results in devices with higher diffraction efficiency.We have also researched on LCoS SLMs and used them for two different applications: (a) photophoretic-trap volumetric displays and (b) holographic video displays. In the first case, aberrations including spherical, astigmatism, and coma can make particles to trap tighter in the focal point of the beam. Also, a new approach for holographic computations is presented which uses the electromagnetic nature of light in Maxwell Equations to find a unique phase map for every specific 3D object in space.

Achieving a low noise level is of great interest to the forest machine industry. Traditionally this is obtained by using passive noise reduction, i.e. by using materials for sound isolation and sound absorption. Especially designs to attenuate low frequency noise tend to be bulky and impractical from an installation point of view. An alternative solution to the problem is to use active noise control (ANC). The basic principle of ANC is to generate an anti-noise signal designed to destructively interfere with the unwanted noise. In this thesis two algorithms (Feedback FxLMS and Feedforward FxLMS) are implemented and evaluated for use in the ANC-system. The ANC-system is tuned to the specific environment in the driver’s cabin of a Komatsu forest machine. The algorithms are first tested in a simulated environment and then in real-time inside a forest machine. Simulations are made both in Matlab and in C using both generated signals and recorded signals. The C code is implemented on the Analog Devices Blackfin DSP card BF526. The result showed a significantly reduction of the sound pressure level (SPL) in the driver’s cabin. The noise attenuation obtained using the Feedback FxLMS was approximately 14 dB for a tonal 100 Hz signal and 11 dB using recorded engine noise from a forest machine at 850 rpm.