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An fpga based architecture for native protocol testing of multi-gbps source-synchronous devicesGray, Carl Edward 03 July 2012 (has links)
This thesis presents methods for developing FPGA-based test solutions that solve the challenges of evaluating source-synchronous and protocol-laden systems and devices at multi-gigabit per second signaling rates. These interfaces are becoming more prevalent in emerging designs and are difficult to test using traditional automated test equipment (ATE) and test instrumentation which were designed for testing designs utilizing synchronous and deterministic signaling. The main motivation of this research was to develop solutions that address these challenges. The methods shown in this thesis are used to design a test architecture consisting of custom hardware components, reprogrammable digital logic for hardware integration, and a software interface for external data transport and configuration. The hardware components consist of a multi-GHz field programmable gate array (FPGA) based interface board providing processing, control, and data capabilities to the system and enhanced by one or more application modules which can be tailored for specific test functionality compatible with source-synchronous and protocol interfaces. Software controls from a host computer provide high and low level access to the internal tester data and configuration memory space.
The architecture described in this thesis is demonstrated through a specific test solution for a high-speed optical packet switched network called the Data Vortex. Reprogrammable firmware and software controls allow for a high degree of adaptability and application options. The modularized implementation of the hardware elements introduces additional adaptability and future upgradability, capable of incorporating new materials and design techniques for the test platform and application modules.
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Finite element modelling of hydroelasticity in hull-water impactsStenius, Ivan January 2006 (has links)
<p>The work in this thesis focuses on the use of explicit finite element analysis (FEA) in the modelling of fluid-structure interaction of panel-water impacts. Paper A, considers modelling of a two-dimensional rigid wedge impacting a calm water surface. From analytical methods and results of a systematic parameter study a generalised approach for determination of fluid discretization and contact parameters in the modelling of arbitrary hull-water impact situations is developed and presented. In paper B the finite element modelling methodology suggested in paper A is evaluated for elastic structures by a convergence study of structural response and hydrodynamic load. The structural hydroelastic response is systematically studied by a number of FE-simulations of different impact situations concerning panel deadrise, impact velocity and boundary conditions. In paper B a tentative method for dynamic characterization is also derived. The results are compared with other published results concerning hydroelasticity in panel water impacts. The long-term goal of this work is to develop design criteria, by which it can be determined whether the loading situation of a certain vessel type should be regarded as quasi-static or dynamic, and which consequence on the design a dynamic loading has.</p>
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Loads and responses for planing craft in wavesRosén, Anders January 2004 (has links)
<p>Experimental and numerical analysis of loads and responses for planing craft in waves is considered. Extensive experiments have been performed on a planing craft, in full-scale as well as in model scale. The test set-ups and significant results are reviewed. The required resolution in experiments on planing craft in waves, concerning sampling frequencies, filtering and pressure transducer areas, is investigated. The aspects of peak identification in transient signals, fitting of analytical cumulative distribution functions to sampled data, and statistical convergence are treated.</p><p>A method for reconstruction of the momentary pressure distribution at hull-water impact, from measurements with a limited number of transducers, is presented. The method is evaluated to full-scale data, and is concluded to be applicable in detailed evaluation of the hydrodynamic load distribution in time-domain simulations. Another suggested area of application is in full-scale design evaluations, where it can improve the traceability, i.e. enable evaluation of the loads along with the responses with more confidence.</p><p>The presented model experiment was designed to enable time-domain monitoring of the complete hydromechanic pressure distribution on planing craft in waves. The test set-up is evaluated by comparing vertical forces and pitching moments derived from acceleration measurements, with the corresponding forces derived with the pressure distribution reconstruction method. Clear correlation is found.</p><p>An approach for direct calculations of loads, as well as motion and structure response, is presented. Hydrodynamic loads and motion responses are calculated with a non-linear time-domain strip method. Structure responses are calculated by applying momentary distributed pressure loads, formulated from hydrodynamic simulations, on a global finite element model with inertia relief. From the time series output, limiting conditions and extreme responses are determined by means of short term statistics. Promising results are demonstrated in applications, where extreme structure responses derived by the presented approach, are compared with responses to equivalent uniform rule based loads, and measured responses from the full-scale trials. It is concluded that the approach is a useful tool for further research, which could be developed into a rational design method.</p>
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Improved architectures for fused floating-point arithmetic unitsSohn, Jongwook 05 November 2013 (has links)
Most general purpose processors (GPP) and application specific processors (ASP) use the floating-point arithmetic due to its wide and precise number system. However, the floating-point operations require complex processes such as alignment, normalization and rounding. To reduce the overhead, fused floating-point arithmetic units are introduced. In this dissertation, improved architectures for three fused floating-point arithmetic units are proposed: 1) Fused floating-point add-subtract unit, 2) Fused floating-point two-term dot product unit, and 3) Fused floating-point three-term adder. Also, the three fused floating-point units are implemented for both single and double precision and evaluated in terms of the area, power consumption, latency and throughput. To improve the performance of the fused floating-point add-subtract unit, a new alignment scheme, fast rounding, two dual-path algorithms and pipelining are applied. The improved fused floating-point two-term dot product unit applies several optimizations: a new alignment scheme, early normalization and fast rounding, four-input leading zero anticipation (LZA), dual-path algorithm and pipelining. The proposed fused floating-point three-term adder applies a new exponent compare and significand alignment scheme, double reduction, early normalization and fast rounding, three-input LZA and pipelining to improve the performance. / text
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The metallic elephant in the room : short range flights, high-speed rail, and the environmentJohnson, Donovan Theodore 25 July 2011 (has links)
It is of nearly universal acceptance that one of the pillars of American economic success over the course of the 20th century was the rapid development of infrastructure. Transportation infrastructure has been of particular importance in the rise of the United States and attributed to the spread of an increasingly mobile culture. Americans undoubtedly enjoy traveling, and the ability to do so with relative ease is of immense value to many.
In Texas, the majority of economic activity takes place within what is colloquially known as the “Texas Triangle”, an area bounded by the large metropolitan areas of Houston, Dallas-Ft. Worth, and San Antonio. Intensive population growth in Texas, anchored by the triangle, has led to increasing road congestion on many routes, especially along Interstates 35 and 10. This congestion, and the wasted time and money that comes with it, are of increasing concern to the future economic vitality of the state.
The Texas Triangle is also served by extensive aviation links via major airports in the major metropolitan areas, as well as smaller airports in other parts of the region. These flights, operated by American Airlines, Continental Airlines, and Southwest Airlines are frequent, but emit large amounts of greenhouse gases that contribute to ground level pollution and possibly climate change. High-speed rail has been considered by many to be a superior environmental option for intercity routes with lengths inherent to the Texas Triangle.
However, given the fact that Texas is the top emitter of carbon dioxide in the U.S. and relies on an energy mix that is primarily fossil fuel powered; would a potential high-speed rail in Texas outperform the current air system environmentally, given similar passenger miles traveled? This report examines the environmental emissions of high-speed rail and compares it to the environmental emissions of our current aviation system, taking into account a life-cycle perspective. / text
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Coded Modulation for High Speed Optical Transport NetworksBatshon, Hussam George January 2010 (has links)
At a time where almost 1.75 billion people around the world use the Internet on a regular basis, optical communication over optical fibers that is used in long distance and high demand applications has to be capable of providing higher communication speed and re-liability. In recent years, strong demand is driving the dense wavelength division multip-lexing network upgrade from 10 Gb/s per channel to more spectrally-efficient 40 Gb/s or 100 Gb/s per wavelength channel, and beyond. The 100 Gb/s Ethernet is currently under standardization, and in a couple of years 1 Tb/s Ethernet is going to be standardized as well for different applications, such as the local area networks (LANs) and the wide area networks (WANs). The major concern about such high data rates is the degradation in the signal quality due to linear and non-linear impairments, in particular polarization mode dispersion (PMD) and intrachannel nonlinearities. Moreover, the higher speed transceivers are expensive, so the alternative approaches of achieving the required rates is preferably done using commercially available components operating at lower speeds.In this dissertation, different LDPC-coded modulation techniques are presented to offer a higher spectral efficiency and/or power efficiency, in addition to offering aggregate rates that can go up to 1Tb/s per wavelength. These modulation formats are based on the bit-interleaved coded modulation (BICM) and include: (i) three-dimensional LDPC-coded modulation using hybrid direct and coherent detection, (ii) multidimensional LDPC-coded modulation, (iii) subcarrier-multiplexed four-dimensional LDPC-coded modulation, (iv) hybrid subcarrier/amplitude/phase/polarization LDPC-coded modulation, and (v) iterative polar quantization based LDPC-coded modulation.
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Impact resistance of high strength fiber reinforced concreteZhang, Lihe 05 1900 (has links)
Concrete structures may be subjected to dynamic loading during their service life. Understanding the dynamic properties of concrete structures is becoming critical because of the increased concern about the dynamic loading of both civilian and military structures, and especially, the recent increase in terrorist attacks on structures. Fiber reinforced concrete (FRC) is known to exhibit superior performance in its post-peak energy absorption capacity, (i.e., toughness) under flexural and tensile loading. However, the behavior of fiber reinforced concrete under compressive impact has not previously been investigated. In the present research, the response of fiber reinforced concrete was investigated over the full strain rate regime, from static loading to high strain rate loading, and finally to impact loading. The compressive toughness of FRC under static loading was studied using an existing Japanese standard (JSCE SF-5). Then, a test method for FRC under compressive impact loading was developed, involving the use of a high speed video camera system to measure the deformation of FRC cylinders under compressive impact.
The strain rate sensitivity of FRC in both flexure and compression was also fully investigated. FRC was found to have higher strengths under impact loading (both flexural and compressive) than under static loading. The compressive toughness under impact loading increased due to the high peak load and the high strain capacity. FRC under flexural impact loading showed a greater strength improvement than under static flexure. FRC displays a much higher Dynamic Improvement Factor (DIF) under flexural impact than under compressive impact. It gave an overall higher performance under impact than under static loading. It also exhibited a higher strain rate sensitivity than plain concrete in both compression and flexure.
Damage analysis, in terms of loss of strain energy, was carried out based on damage mechanics principles. Damage was found to increase with increasing strain rate. A new constitutive model was proposed to account for the relationship between DIF (Comp) and strain rate and the data derived from the model were found to be consistent with the experimental results.
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High-speed, high-performance wireless and wireline applications using silicon-germanium BiCMOS technologiesShankar, Subramaniam 17 September 2013 (has links)
The objective of the research in this dissertation is to demonstrate the viability of using silicon-germanium (SiGe) bipolar/complementary metal-oxide semiconductor (BiCMOS) technologies in novel high-speed, high-performance wireless and wireline applications. These applications include self-healing integrated systems, W-Band phased array radar systems, and multi-gigabit wireline transceiver systems. The contributions from this research are summarized below:
1. Design of a wideband 8-18 GHz signal source with the best reported tuning range and die area combination for self-healing applications [95].
2. Design of a robust, multi-band 8-10/ 16-20 GHz signal source with amplitude-locking for self-healing applications. A figure-of-merit (FoM) is proposed that combines tuning range and die area, and this work achieves the best FoM compared with state-of-the art [51].
3. First ever reported on-die healing of image-rejection ratio of an 8-18 GHz mixer integrated with the multi-band test signal source [52], [96].
4. Design of a 94 GHz differential Colpitts oscillator with 14% tuning range that spans 86-99 GHz for phased-array radar systems.
5. Identification of technology platform related bottlenecks in multi-gigabit wireline systems. A novel study of linearity of switching transistors in a current-mode logic (CML) gate.
6. A novel FoM that can be used to predict large-signal CML delay using small-signal Y-parameter techniques [97].
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Sustainable Transportation Decision-Making: Spatial Decision Support Systems (SDSS) and Total Cost AnalysisKim, Hwan Yong 03 October 2013 (has links)
Building a new infrastructure facility requires a significant amount of time and expense. This is particularly true for investments in transportation for their longstanding and great degree of impact on society. The scope of time and money involved does not mean, however, we only focus on the economies of scale and may ignore other aspects of the built environment. To this extent, how can we achieve a more balanced perspective in infrastructure decision-making? In addition, what aspects should be considered when making more sustainable decisions about transportation investments? These two questions are the foundations of this study.
This dissertation shares its process in part with a previous research project – Texas Urban Triangle (TUT). Although the TUT research generated diverse variables and created possible implementations of spatial decision support system (SDSS), the methodology still demands improvement. The current method has been developed to create suitable routes but is not designed to rank or make comparisons. This is admittedly one of the biggest shortfalls in the general SDSS approach, but is also where I see as an opportunity to make alternative interpretation more comprehensive and effective. The main purpose of this dissertation is to develop a Spatial Decision Support System (SDSS) that will lead to more balanced decision-making in transportation investment and optimize the most sustainable high-speed rail (HSR) route.
The decision support system developed here explicitly elaborates the advantages and disadvantages of a transportation corridor in three particular perspectives: construction (fixed costs); operation (maintenance costs); and externalities (social and environmental costs), with a specific focus on environmental externalities. Considering more environmental features in rail routing will offset short-term economic losses and creates more sustainable environments in long-term infrastructure planning.
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Impact resistance of high strength fiber reinforced concreteZhang, Lihe 05 1900 (has links)
Concrete structures may be subjected to dynamic loading during their service life. Understanding the dynamic properties of concrete structures is becoming critical because of the increased concern about the dynamic loading of both civilian and military structures, and especially, the recent increase in terrorist attacks on structures. Fiber reinforced concrete (FRC) is known to exhibit superior performance in its post-peak energy absorption capacity, (i.e., toughness) under flexural and tensile loading. However, the behavior of fiber reinforced concrete under compressive impact has not previously been investigated. In the present research, the response of fiber reinforced concrete was investigated over the full strain rate regime, from static loading to high strain rate loading, and finally to impact loading. The compressive toughness of FRC under static loading was studied using an existing Japanese standard (JSCE SF-5). Then, a test method for FRC under compressive impact loading was developed, involving the use of a high speed video camera system to measure the deformation of FRC cylinders under compressive impact.
The strain rate sensitivity of FRC in both flexure and compression was also fully investigated. FRC was found to have higher strengths under impact loading (both flexural and compressive) than under static loading. The compressive toughness under impact loading increased due to the high peak load and the high strain capacity. FRC under flexural impact loading showed a greater strength improvement than under static flexure. FRC displays a much higher Dynamic Improvement Factor (DIF) under flexural impact than under compressive impact. It gave an overall higher performance under impact than under static loading. It also exhibited a higher strain rate sensitivity than plain concrete in both compression and flexure.
Damage analysis, in terms of loss of strain energy, was carried out based on damage mechanics principles. Damage was found to increase with increasing strain rate. A new constitutive model was proposed to account for the relationship between DIF (Comp) and strain rate and the data derived from the model were found to be consistent with the experimental results.
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