Next generation communication systems are reaching 110Gbps rates. At these frequencies, the skin effect and dielectric loss of copper cables cause inter-symbol interference (ISI) and frequency dependent loss, severely limiting the channel bandwidth. In this thesis, different methods for alleviating ISI are explored. The design of the critical blocks of an adaptive channel equalizer with up to two times oversampling are presented. The circuits were fabricated in a 0.13μm SiGe BiCMOS technology. The linear, adaptive equalizer operates up to 70Gbps and its measured S-parameters exhibit a single-ended peak gain of 12.2dB at 52GHz, allowing for 31dB of peaking between DC and 52GHz. Equalization is demonstrated experimentally at 59Gbps for a cable loss of 17.9dB. These results make it the fastest receive equalizer published to date. A retiming flip-flop operating between 72 and 118 GHz, the highest reported in silicon, is also designed and characterized, showing less than 500-fs jitter.

Next generation communication systems are reaching 110Gbps rates. At these frequencies, the skin effect and dielectric loss of copper cables cause inter-symbol interference (ISI) and frequency dependent loss, severely limiting the channel bandwidth. In this thesis, different methods for alleviating ISI are explored. The design of the critical blocks of an adaptive channel equalizer with up to two times oversampling are presented. The circuits were fabricated in a 0.13μm SiGe BiCMOS technology. The linear, adaptive equalizer operates up to 70Gbps and its measured S-parameters exhibit a single-ended peak gain of 12.2dB at 52GHz, allowing for 31dB of peaking between DC and 52GHz. Equalization is demonstrated experimentally at 59Gbps for a cable loss of 17.9dB. These results make it the fastest receive equalizer published to date. A retiming flip-flop operating between 72 and 118 GHz, the highest reported in silicon, is also designed and characterized, showing less than 500-fs jitter.

This thesis expands upon the dialogue between speed and architecture, investigating how architecture reinterprets the linear city, originally defined by the continuous fabric of the freeway and more recently reconfigured by the high speed rail line. Using the linear city as a site of exploration and high speed rail as a ground to test new typologies of architectural insertions at amplified speed, this thesis produces an extended civic space along the proposed high speed rail line connecting Tampa and Orlando. Combining a series of performance and commercial programs, this new typology will make the obscured visual experience along the extended territory of the rail line legible, through a sequencing of specific architectural intersections, exploring how monumental civic space will be made and occupied in the sprawl of the American city.

The cutting action of a single abrasive grain was investigated using a combination of high-speed scratch tests and finite element models. The high-speed scratch tests were unique in that the cutting conditions of a grinding operation were closely replicated. Two geometries were tested: a round-nosed stylus to approximate a 15-grit abrasive grain and a flat-nosed stylus to approximate a worn 46-grit abrasive grain. The three-dimensional finite element model was unique in that a hybrid Euler-Lagrange method was implemented to efficiently model the interaction between an abrasive grain and a workpiece. The finite element model was initially validated using indentation tests to remove the complexities of relative motion from the validation process. The validation was completed through comparisons to the experimental scratch tests. The results of the analysis revealed several key findings. Rubbing, plowing, and cutting do not display distinct transitions; rather, they coexist with different weightings depending on the scratching speed and the depth of cut. The normal forces increased for a given depth of cut as the scratching speed was increased due to strain-rate hardening of the workpiece. The tangential forces decreased for a given depth of cut as the scratching speed was increased due to a reduction in the coefficient of friction and a change in the cutting mechanics from plowing to cutting. The change in the cutting mechanics was investigated by analyzing the evolution of the scratch profiles as the depth of cut and scratching speed were changed. It was found that higher scratching speeds produced less material pile-up and this was attributed to a change in the cutting mechanics. Due to the change in the cutting mechanics, the specific energy decreased as the depth of cut and scratching speed were increased. A numerical case study revealed that reducing the grain size resulted in: lower forces, lower specific energies, and smaller volumes of subsurface stresses. The finite element model was adapted to work in conjunction with the flat-nosed stylus creating the first model capable of simulating the cutting of an abrasive grain in three dimensions.

The Iterative Closest Point (ICP) algorithm is one of the most commonly used range image processing methods. However, slow operational speeds and high input band-widths limit the use of ICP in high-speed real-time applications. This thesis presents and examines a novel hardware implementation of a high-speed ICP object tracking system that uses stereo vision disparities as input. Although software ICP trackers already exist, this innovative hardware tracker utilizes the efficiencies of custom hardware processing, thus enabling faster high-speed real-time tracking. A custom hardware design has been implemented in an FPGA to handle the inherent bottlenecks that result from the large input and processing band-widths of the range data. The hardware ICP design consists of four stages: Pre-filter, Transform, Nearest Neighbor, and Transform Recovery. This custom hardware has been implemented and tested on various objects, using both software simulation and hardware tests. Results indicate that the tracker is able to successfully track free-form objects at over 200 frames-per-second along arbitrary paths. Tracking errors are low, in spite of substantial noisy stereo input. The tracker is able to track stationary paths within 0.42mm and 1.42degs, linear paths within 1.57mm and 2.80degs, and rotational paths within 0.39degs axis error. With further degraded data by occlusion, the tracker is able to handle 60% occlusion before a slow decline in performance. The high-speed hardware implementation (that uses 16 parallel nearest neighbor circuits), is more then five times faster than the software K-D tree implementation. This tracker has been designed as the hardware component of ‘FastTrack’, a high frame rate, stereo vision tracking system, that will provide a known object’s pose in real-time at 200 frames per second. This hardware ICP tracker is compact, lightweight, has low power requirements, and is integratable with the stereo sensor and stereo extraction components of the FastTrack’ system on a single FPGA platform. High-speed object tracking is useful for many innovative applications, including advanced spaced-based robotics. Because of this project’s success, the ‘FastTrack’ system will be able to aid in performing in-orbit, automated, remote satellite recovery for maintenance. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-07-15 22:50:30.369

Electroabsorption modulators (EAMs) are fundamental components in optical communication systems. Their response is governed by a set of parameters inherent to their internal structure and by the external electrical components used to drive them. The first part of this thesis discusses a new method for the extraction of values for these parameters. The use of EAMs as both optical modulators and photodetectors is exploited for the purpose of parameter extraction. The proposed method allows the estimation of the parameters which govern the internal frequency response of EAMs without any knowledge of the characteristics of the electrical interconnect used to drive them. The procedure also removes the need for an accurately calibrated optical transmitter and receiver pair normally used during the characterization of optoelectronic components. Analytic description and experimental verification are presented. In the second part of this thesis, direct demultiplexing of a 10 Gbit/s channel from a 160 Gbit/s optical time division multiplexing (OTDM) signal using a single lumped, electrically driven EAM is experimentally presented for the first time. Direct demultiplexing is made possible by using an electrical driving signal for the EAM consisting of a sum of in-phase harmonics of the base channel rate. The use of a single EAM as an optical gate is quasi-analytically compared with the common approach of cascading two EAMs when performing 160 Gbit/s to 10 Gbit/s demultiplexing. The analysis reveals that the use of a single EAM is beneficial in terms of lower penalty with respect to degradations in the extinction ratio and width of the pulses used in the OTDM signal. The last part of this thesis introduces an electrical distributed oscillator which works in a regime of oscillation similar to that of mode locked laser (MLL) systems. The oscillator offers the flexibility of producing other waveforms not found in MLLs and has the potential to generate the required electrical driving signal for a single EAM OTDM demultiplexer. Other possible applications of the oscillator include the generation of short pulses for use in radar systems and wireless personal area networks. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2011-06-30 14:41:42.625

No description available.

Open rotors are known to have significant advantages in terms of propulsive efficiency. These advantages translate directly in reduced fuel burn so that they nowadays benefit from a surge of interest. At the same time, recent advances in numerical simulations make the application of multidisciplinary optimization for the demanding design of transonic propeller blades, an affordable option. Therefore, an optimization method in which the performance objectives of aerodynamics, aeroacoustics and aeroelasticity compete against each other, is developed and applied for the design of high-speed single-rotation propellers. The optimization is based on Multi-Objective Differential Evolution (MODE).This technique is a particular kind of evolutionary algorithm that mimics the natural evolution of populations by relying on the selection, recombination and eventually mutation of blade designs, each of them being represented by a vector of design variables (e.g. chord width, tip sweep, etc). MODE has the advantage of dealing concurrently with all the objectives in the selection of potentially promising designs among a population. In order to keep the computational cost within reasonable margins, the assessment of the performance of proposed designs is done in a two-level approach. A metamodel provides performance estimates for each proposed design at extremely low computational effort while high-fidelity analysis codes provide accurate performance values on some promising designs at much higher cost. To safeguard the accuracy of the estimates, the metamodel is initially trained on a population that is specifically assembled for that purpose. The training is repeated from time to time with the high-fidelity performance values of promising designs. Different high-fidelity tools have been developed and used for the assessment of performance.The CFD-tool performs steady RANS simulations of a single blade passage of the isolated propeller in free air under zero angle of attack. These simulations provide the aerodynamic performance values. The full propeller is modelled thanks to cyclic boundary conditions. The k - ε turbulence model is used in combination with wall treatment. Adiabatic no-slip wall conditions are imposed on the spinner and blade surfaces whereas the test-section radial boundary is reproducing the effects of a pressure far-field. This approach has proven its robustness and, above all, its accuracy as satisfactory agreement with experimental results has been found for different operating conditions over a wide range of blade shapes, as well as sufficient grid independency. In the post-processing of the aerodynamic results, the Sound Pressure Level (SPL)is computed for tonal noise at various observer locations by the aeroacoustic solver(CHA). Formulation 1A from Farassat is used for this purpose. This formulation is related to the inhomogeneous wave equation derived from Lighthill's acoustic analogy by Ffowcs Williams and Hawkings (FW-H). It benefits from the partial decoupling of the acoustic and aerodynamic aspects and is particularly suited to compute the noise from propellers. The thickness noise and loading noise are expressed by separate equations in the time-domain whereas the quadrupole source term is dropped from the original FW-H equation. The blade surface is chosen as integration surface and a newly developed truncation technique is applied to circumvent the mathematical singularity arising when parts of the blade reach sonic conditions in terms of kinematics with respect to the observer. This approach delivers accurate values at acceptable computational cost. Besides, CSM-computations make use of a finite elements solver to compute the total mass of the blade as well as the stresses resulting from the centrifugal and aerodynamic forces. Considering the numerous possibilities to tailor the blade structure so that it properly takes on the stresses, only a simplified blade model is implemented. [...]

Digital Image-based Elasto-Tomography (DIET) is an emerging technology for non-invasive breast cancer screening. This technology relies on obtaining high resolution images of a breasts surface under high frequency actuation; typically 50-100Hz. Off-the-shelf digital cameras are unable to capture images directly at these speeds and current digital camera set-ups that are potentially capable of high speed image capture are either low in resolution, expensive, or occupy a volume too large to have them placed about the breast in a dense array. A method is presented for obtaining the required high speed image capture at a resolution of 1280x1024 (1.3 mega-pixels) and actuation frequency of 100Hz. The apparatus uses two Kodak CMOS KAC-9648 imaging sensors in combination with frame grabbers and the dSpace control system, to produce an automated image capture system. The final working system produced images that enabled effective 3D motion tracking of the surface of a silicon phantom actuated at 100Hz. The surface of the phantom was strobed at pre-selected phases from 0 to 360 degrees, and an image was captured for each phase. The times at which image capture occurred were calculated for a phase lag increment of 10 degrees resulting in an image effectively every 0.00028s for the actuator cycle of 0.01s. The comparison of the actual trigger times and pre-selected ideal trigger times gave a mean absolute error of 1.4%, thus demonstrating the accuracy of the final system.

Accurate methods for glottal feature extraction include the use of high-speed video imaging (HSVI). There have been previous attempts to extract these features with the acoustic recording. However, none of these methods compare their results with an objective method, such as HSVI. This thesis tests these acoustic methods against a large diverse population of 46 subjects. Two previously studied acoustic methods, as well as one introduced in this thesis, were compared against two video methods, area and displacement for open quotient (OQ) estimation. The area comparison proved to be somewhat ambiguous and challenging due to thresholding effects. The displacement comparison, which is based on glottal edge tracking, proved to be a more robust comparison method than the area. The first acoustic methods OQ estimate had a relatively small average error of 8.90% and the second method had a relatively large average error of -59.05% compared to the displacement OQ. The newly proposed method had a relatively small error of -13.75% when compared to the displacements OQ. There was some success even though there was relatively high error with the acoustic methods, however, they may be utilized to augment the features collected by HSVI for a more accurate glottal feature estimation.