The growing interest towards wireless communication services over the recent years has increased the demand for radio spectrum. Inefficient spectrum management together with the scarcity of the radio spectrum is a limiting factor for the development of modern wireless networks. As a solution, the idea of cognitive radio networks (CRNs) is introduced to use licensed spectrum for the benefit of the unlicensed secondary users. However, the preemptive priority of the licensed users results in random resource availabilities at the secondary networks, which makes the quality-of-service (QoS) support challenging. With the increasing demand for elastic/interactive data services (internet based services) and wireless multimedia services, QoS support becomes essential for CRNs. This research investigates the voice and elastic/interactive data service support over CRNs, in terms of their delay requirements. The packet level requirements of the voice service and session level delay requirements of the elastic/interactive data services are studied. In particular, constant-rate and on-off voice traffic capacities are analyzed over CRNs with centralized and distributed network coordination. Some generic channel access schemes are considered as the coordination mechanism, and call admission control algorithms are developed for non-fully-connected CRNs. Advantage of supporting voice traffic flows with different delay requirements in the same network is also discussed. The mean response time of the elastic data traffic over a centralized CRN is studied, considering the shortest processor time with and without preemption and shortest remaining processor time service disciplines, in comparison with the processor sharing service discipline. Effects of the traffic load at the base station and file length (service time requirement) distribution on the mean response time are discussed. Finally, the relationship between the mean response times of interactive and elastic data traffic is studied.

In this thesis, a comparison of the body SAR value of five planar WLAN antennas including two coupled-fed shorted monopole antennas, a coupled-fed loop antenna, a monopole antenna, and a monopole slot antenna for tablet PC applications are presented. A required minimum distance between the antenna and the testing flat phantom to meet the 1-g body SAR requirement of 1.6 W/kg has been determined. Results show that the body SAR results of the coupled-fed loop antenna are lowest among the five tested antennas. Detailed results and discussion are presented in this thesis. Also, a comparison of the body SAR value of a planar antenna and an antenna with 3-D bent structure are presented.

In this thesis, WWAN/LTE and LTE MIMO antennas for ultrabook computers are presented. The MIMO antenna system comprises an eight-band LTE/WWAN antenna and a three-band LTE antenna. The bandwidth of the eight-band LTE/WWAN antenna is enhanced by using an embedded parallel resonant circuit, which can result in dual-resonance excitation of the lowest resonant mode of the antenna. The bandwidth of the antenna¡¦s lower band can hence cover the LTE700/GSM850/900 operation. A design technique of improving the isolation of the MIMO antenna system is also presented. The isolation enhancement is obtained by embedding a 0.5-wavelength slot in the conductive supporting plate of the upper cover of the ultrabook computer. The embedded slot can attract the excited surface currents in the conductive supporting plate and decrease the coupling between the MIMO antennas through the coupling of the surface currents. The isolation between the MIMO antennas can hence be enhanced. Moreover, this technique will not lead to decreased radiation efficiency and impedance matching of the MIMO antennas, which is attractive for practical applications.

The turbine blade platform can be protected from hot mainstream gases by injecting cooler air through the gap between stator and rotor. The effectiveness of this film cooling method depends on the geometry of the slot, the quantity of injected air, and the secondary flows near the platform. The purpose of this study was to measure the effect of the upstream vane or stator on this type of platform cooling, as well as the effect of changes in the width of the gap. Film cooling effectiveness distributions were obtained on a turbine blade platform within a linear cascade with upstream slot injection. The width of the slot was varied as well as the mass flow rate of the injected coolant. Obstacles were placed upstream to model the effect of the upstream vane. The coolant was injected through an advanced labyrinth seal to simulate purge flow through a stator-rotor seal. The width of the opening of this seal was varied to simulate the effect of misalignment. Stationary rods were placed upstream of the cascade in four phase locations to model the unsteady wake formed at the trailing edge of the upstream vane. Delta wings were also placed in four positions to create a vortex similar to the passage vortex at the exit of the vane. The film cooling effectiveness distributions were measured using pressure-sensitive paint (PSP). Reducing the width of the slot was found to decrease the area of coolant coverage, although the film cooling effectiveness close to the slot was slightly increased. The unsteady wake was found to have a trivial effect on platform cooling, while the passage vortex from the upstream vane may significantly reduce the film cooling effectiveness.

In this thesis, an analysis technique for the slot coupled patch antennas using MoM in conjunction with the closed form Green&rsquo / s functions is presented. Slot coupled patch antennas are fed by a microstrip open stub which is coupled to the patch through an electrically small slot. Current distributions over the microstrip line, slot line and the patch are represented by rooftop basis functions. First, a relatively simple structure, microstrip coupled slot line is investigated using the proposed technique. Then the method is extended to the slot coupled patch antenna geometry. By using the method, current distributions on the feedline and the patch are calculated for a generic slot coupled patch antenna. Then by using the distributions, return scattering parameters of the antenna is approximated with complex exponentials using Prony&rsquo / s method. A parametric study is carried out to observe the effect of each antenna component on the antenna performance. Current distributions and return loss calculations are repeated for modified antennas to observe and demonstrate the performance differences. All simulations are verified using HFSS&reg / software and the results available in the literature.

In this thesis, a wideband dual polarized microstrip antenna is designed, manufactured and measured. Slot coupled patch antenna structure is considered in order to achieve the wideband characteristic. Although rectangular shaped slot coupled patch antennas are widely used in most of the applications, their utilization in dual polarized antenna structures is not feasible due to space limitations regarding the positioning of two separate coupling slots for each polarization. For a rectangular slot, the parameter that affects the amount of coupling is the slot length. On the other hand when a H-shaped slot is considered, both the length of the center arm and the length of the side legs determine the coupling efficiency. This flexibility about the optimization parameters of the H-shaped slot makes it possible to position the two coupling slots within the boundaries of the patch antenna. Therefore, H-shaped slot coupled patch antennas are studied in this thesis. In order to investigate the effects of slot and antenna dimensions on the radiation characteristics of the antenna, a parametric study is performed by analyzing the antenna structure with a planar electromagnetic field simulation software (Ansoft Designer). By the help of the experience gained through this parametric study, a dual polarized patch antenna that can be used at the base station of a cellular system (DCS: 1710&ndash / 1880 MHz) is designed. Before manufacturing the antenna, dimensions of the antenna are re-tuned by considering a finite sized ground plane in the simulations. Finally, the antenna is manufactured and measured. An acceptable agreement is obtained between the measurement and the simulation results.

Series-fed printed slot antenna arrays excited by microstrip lines are low profile, easy to manufacture, low cost structures that found use in applications that doesn&rsquo / t require high power levels with having advantage of easy integration with microwave front-end circuitry. In this thesis, design and analysis of microstrip line fed slot antenna arrays are investigated. First an equivalent circuit model that ignores mutual coupling effects between slots is studied. A 6-element array is designed by using this equivalent circuit model. From the measurement and electromagnetic simulation results of this array, it is concluded that mutual coupling effects should be considered in order to achieve a successful design that meets the design specifications related to the main beam direction and sidelobe levels of the antenna. Next, an improved equivalent circuit model proposed for stripline fed slot antenna arrays is studied. It is observed that, the mutual coupling effects are incorporated into the equivalent model through the utilization of active impedance concept. Finally, the design equations proposed in the improved equivalent circuit model are derived for the microstrip line fed slot antenna array structure. To demonstrate the validity and the accuracy of the derived design equations, results obtained by the proposed analysis method are compared with simulation and measurement results. It is concluded that the proposed method successfully predicts the radiation pattern of the array by including the mutual coupling effects.

Der achte Band der wissenschaftlichen Schriftenreihe EINGEBETTETE, SELBSTORGANISIERENDE SYSTEME widmet sich der Synthese von partiell dynamisch rekonfigurierbaren, eingebetteten Systemen. Mit der Möglichkeit Hardwareblöcke zur Laufzeit auf programmierbaren Bausteinen neu zu konfigurieren, lässt sich eine höhere Flexibilität im Vergleich zu einer Hardwarerealisierung in eingebettete Systeme integrieren. Gleichzeitig sind diese Systeme durch eine gesteigerte Performance gegenüber Software gekennzeichnet. Die Flexibilität kann ausgenutzt werden, um kleinere Schaltkreise bei gleichem Funktionsumfang einzusetzen. Für die Integration von Rekonfigurierung sind zusätzliche Entwurfschritte im Design Flow notwendig. Herr Meisel stellt hierfür in seiner Arbeit eine Entwurfsmethodik vor und geht im Besonderen auf die Partitionierung, Platzierung und Steuerung in dynamisch rekonfigurierbaren, eingebetteten Systemen ein. Um eine vergleichsweise effizient zu realisierende Partitionierung des Systems zu erhalten, wurde das Overlaying Verfahren aus dem Bereich der Speicherverwaltung für dynamische Rekonfigurierung adaptiert. Für das Platzierungsverfahren wurden Rekonfigurierungen als Markov Kette modelliert, um so zu einer Minimierung der durchschnittlichen Rekonfigurierungsdauer zu gelangen. Die vorgestellte Rekonfigurierungssteuerung fokussiert auf einer ressourcensparenden Hardware Implementierung. Mit einem Entwurfsbeispiel werden die Vorteile und Ergebnisse des Ansatzes anschaulich illustriert. So kann der Leser die Mächtigkeit des entwickelten Ansatzes nachvollziehen und wird motiviert, die entwickelte Methodik auf weitere Anwendungsfälle zu übertragen. / Volume 8 of scientific series EINGEBETTETE, SELBSTORGANISIERENDE SYSTEME (Embedded Self-Organized Systems) addresses the synthesis of partially dynamically reconfigurable embedded systems. With the ability to configure hardware blocks during run-time, more flexibility can be integrated in embedded systems. At the same time, these systems have better performance than functions implemented in software. Through this flexibility it is possible to use smaller circuits without limiting the functionality. For the integration of reconfiguration into embedded systems, additional design steps are required. Mr. Meisel presents a design methodology for the design flow and primarily concerns the problem of partitioning, placement, and reconfiguration control in dynamically reconfigurable embedded systems. The implemented partitioning of the system is based on the adapted memory management concept of Overlaying. For the placement method the configurations are modeled as Markov chain, in order to minimize the average reconfiguration time. The presented reconfiguration control unit focuses on a resource-saving hardware implementation. The benefits and results of the approach are clearly illustrated with a design sample. The reader can understand the power of developed approach and is motivated to transfer the developed methodology to more use cases.

Optical biosensors are increasingly being considered for lab-on-a-chip applications due to their benefits such as small size, biocompatibility, passive behaviour and lack of the need for fluorescent labels. The light guiding mechanisms used by many of them result in poor overlap of the optical field with the target molecules, reducing the maximum sensitivity achievable. This thesis presents a new platform for optical biosensors, namely slotted photonic crystals, which engender higher sensitivities due to their ability to confine, spatially and temporally, the peak of optical mode within the analyte itself. Loss measurements showed values comparable to standard photonic crystals, confirming their ability to be used in real devices. A novel resonant coupler was designed, simulated, and experimentally tested, and was found to perform better than other solutions within the literature. Combining with cavities, microfluidics and biological functionalization allowed proof-of-principle demonstrations of protein binding to be carried out. High sensitivities were observed in smaller structures than most competing devices in the literature. Initial tests with cellular material for real applications was also performed, and shown to be of promise. In addition, groundwork to make an integrated device that includes the spectrometer function was also carried out showing that slotted photonic crystals themselves can be used for on-chip wavelength specific filtering and spectroscopy, whilst gas-free microvalves for automation were also developed. This body of work presents slotted photonic crystals as a realistic platform for complete on-chip biosensing; addressing key design, performance and application issues, whilst also opening up exciting new ideas for future study.

Introduction: The objective of this experimental research was to evaluate the slot’s vertical dimension and profile of four different 0.018″ self-ligating brackets and to identify the level of tolerance accepted by manufacturers during the fabrication process. It was then possible to calculate and compare the torque play of those brackets using the measured values and the nominal values. Material and Methods: Twenty-five 0.018″ self-ligating brackets of upper left central incisors from the following manufacturers, Speed® (Strite Industries, Cambridge, Ontario, Canada), InOvationR® (GAC, Bohemia, NY, USA), CarriereLX® (Ortho Organizers, Carlsbad, CA, USA) and SmartClip® (3M Unitek, Monrovia, CA, USA), were evaluated using electron microscopy with 150X images. The height of each bracket was measured at every 100 microns of depth from the lingual wall at five different levels. A Student T test was then used to compare our results with the manufacturer’s stated value of 0.018″. To determine if there was a significant difference between the four manufacturers, analysis of variance (ANOVA) was performed at the significance level of p<0.05. The torque play was then calculated using geometrical formulas. Results: On average, Speed brackets were oversized by 2.7%[MV 0.0185″ (SD:0.002)], InOvationR by 3.7% [MV 0.0187″ (SD:0.002)], CarriereLX by 3.2% [MV 0.0186″ (SD:0.002)] and SmartClipSL by 5.0% [MV 0.0189″ (SD:0.002)]. The height of all brackets was significantly higher than the nominal value of 0.018″ (p<0.001). The slot of SmartClip brackets was significantly larger than those of the other three manufacturers (p<0.001). None of the brackets studied had parallel gingival and occlusal walls; some were convergent and others divergent. These variations can induce a torque play up to 4.5 degrees with a 0.017″x0.025″ wire and 8.0 degrees with a 0.016″x0.022″ wire. Conclusion: All studied brackets were oversized. None of the brackets studied had parallel gingival and occlusal walls and there was no standard between manufacturers for the geometry of their slots. These variations can cause a slight increase of the torque play between the wire and the bracket compared with the nominal value. / Introduction : Cette recherche a été une étude expérimentale conduite en laboratoire visant à évaluer la dimension verticale ainsi que la géométrie de la lumière de différents boîtiers auto-ligaturants populaires de grandeur 0,018″. Par la suite, il a été possible de calculer mathématiquement la perte de torque engendrée par ces variations. Matériel et méthode : Vingt-cinq boîtiers auto-ligaturants d’incisive centrale supérieure gauche de quatre différents manufacturiers, Speed® (Strite Industries, Cambridge, Ontario, Canada), InOvationR® (GAC, Bohemia, NY, USA), CarriereLX® (Ortho Organizers, Carlsbad, CA, USA) et SmartClip SL® (3M Unitek, Monrovia, CA, USA), ont été évalués en utilisant un microscope à balayage électronique à un grossissement de 150X. La hauteur de la lumière a été mesurée à tous les 100 microns de profondeur à cinq différents niveaux, permettant ainsi d’établir sa hauteur moyenne et d’évaluer le parallélisme de ses parois. Le test T de Student a été utilisé pour déterminer si ces valeurs étaient statistiquement significatives comparativement à la valeur de référence de 0,018″. Un test de variance (ANOVA), avec un seuil de signification p<0,05, a été utilisé pour comparer les boîtiers des différents manufacturiers entre eux. La perte de torque a, par la suite, été calculée théoriquement à l’aide de formules géométriques en fonction d’un fil donné. Résultats : En moyenne, la lumière des boîtiers Speed était surdimensionnée de 2,7% [VM : 0,0185″ (DS : 0,002)], InOvationR de 3,7% [VM 0,0187″ (DS : 0,002)], CarriereLX de 3,2% [VM 0,0186″ (DS : 0,002)] et SmartClip SL de 5,0% [VM 0,0189″ (DS : 0,002)]. La hauteur moyenne des quatre types de boîtiers a démontré une différence statistiquement significative par rapport à la valeur de référence de 0,018″ (p<0,001). Il existe également une différence statistiquement significative entre la hauteur moyenne des boîtiers SmartClip et celle des trois autres manufacturiers (p<0,001). Aucun des boîtiers étudiés n’avait les parois gingivales et occlusales parallèles, certaines étaient divergentes, d’autres convergentes. Ces variations peuvent engendrer cliniquement une perte de torque jusqu’à 4,5 degrés avec un fil 0,017″x0,025″ et jusqu’à 8,0 degrés avec un fil 0,016″x0,022″. Conclusion : La lumière de tous les boîtiers étudiés était légèrement surdimensionnée. La géométrie de la lumière variait d’un manufacturier à l’autre, certains boîtiers étaient convergents et d’autres divergents. Ces variations causées par les méthodes de fabrication engendrent une perte de torque supplémentaire par rapport à la valeur nominale.