In this thesis, a novel low power multiplier design is introduced. We utilize the bypassing logic to construct a multiplier based on ripple carry array to minimize the switching activities rather than carry save array for the low power requirement and tree structure to enhance the performance. The advantage of using the bypassing logic in the ripple carry array multiplier is that it can use less extra hardware and achieve more power saving compared with conventional multipliers. The design of our circuit uses the standard TSMC 0.18um technology and simulates with Hspice. According to the simulation results, the proposed design can obtain power saving around 15% more than conventional multipliers, although it must occupy larger area.

The first topic of this thesis is a C-less and R-less ASK (Amplitude Shift Keying) demodulator design for wireless implantable devices. Lots of prior ASK demodulators were composed of one or more capacitors which might be integrated in a chip or positioned off-chip on a PCB (Printed Circuit Board). The capacitor increases the area of the implantable system regardless of on-chip or off-chip, which violates the small-scale requirement for implanted applications. Thus, this work proposes a miniature ASK demodulator without any passive elements, i.e., R or C. The noise margin of the envelope detector in the C-less ASK demodulator is enlarged such that any Schmitt trigger or current limiting resistor is no longer needed. It results in the number of transistors required for the ASK demodulator circuit is reduced to 12. The second topic of this thesis is a design of a low-power 2-dimensional bypassing multiplier. The proposed bypassing cells constituting the multiplier skip redundant signal transitions when the horizontally (row) partial product or the vertically (column) operand is zero. Thorough post-layout simulations show that the power dissipation of the proposed design is reduced by more than 41% compared to the prior design with obscure penalty of delay and area.

Tidal inlets on sandy shorelines separate barrier islands and serve as a conduit for transport of sand and water between embayments and oceans, seas, or other tidally influenced waterbodies. Tides and waves induce currents along the coastline that transport sediment across-shore and alongshore. Coastal managers must optimize barrier-inlet system stability while conserving limited sediment resources, and often base management decisions and engineering design upon geomorphic and numerical models that predict the morphological behavior of tidal inlets on short-to-medium timescales (years to decades). The overall goal of this study was threefold. First, to provide science-based practical guidance for regional sediment management in the vicinity of tidal inlets. Secondly, to enhance the understanding of the temporal and spatial scales of sediment pathways in these regions through numerical simulation of traced sediment transport. And, third, to combine these lessons learned in both regional sediment management and analysis of morphodynamic and sediment bypassing pathways with application to a common practical management practice of inlet shoal mining and adjacent beach placement. The temporal and spatial scales controlling the morphodynamics of barrier-inlet systems were reviewed within a regional sediment management context. Next, the application of regional sediment management methods to case studies of multiple barrier-inlet systems in West-Central Florida led to the development of a decision-support tool for regional sediment management (RSM) as applied to barrier-inlet systems. Connecting multiple barrier islands and inlets at appropriate spatio-temporal scales is critical in developing an appropriately scoped sediment management plan for a barrier-inlet system. Evaluating sediment bypassing capacity and overall inlet morphodynamics can better inform regional sand sharing along barrier-inlet coastlines; particularly where sediment resources are scarce and a close coupling between inlet dredging and beach placement is vital to long-term sustainable management. Continued sea-level rise and anthropogenic activities may intensify the need for investigating longer-term processes and expanding regional planning at a centennial timescale, and are acknowledged as challenging tasks for RSM studies going forward. A regionally focused, multi-inlet study was necessary to improve the management plans for the case study inlets (from north to south): John’s Pass, Blind Pass, Pass-a-Grille Inlet, and Bunces Pass. Key recommendations based on the case studies include: 1) allow the natural sediment bypassing to be re-established at Blind Pass inlet through reduced ebb-tidal delta mining, 2) reduce the interruption to sediment bypassing at John’s Pass and Pass-a-Grille inlets through an improved design of the dredged mining areas located along sediment bypassing pathways, 3) allow for continued natural sediment bypassing at Bunces Pass, and, 4) incorporate the cyclic sediment bypassing through swash-bar attachment into the management plan at Bunces Pass and adjacent barrier-islands. Similar systems in other regions may benefit from the lessons derived in this case study of an adaptively managed multi-inlet system. A numerical model that computes hydrodynamics, sediment transport, and morphodynamics including bed layering was incorporated in this study to analyze sediment transport pathways between littoral sources from adjacent beaches and the geomorphic features of an idealized tidal inlet designed to imitate the John’s Pass tidal inlet in West-central Florida, USA. This study developed a methodology to numerically trace sediment transport, deposition and erosion. This method was applied to investigate sediment-bypassing pathways under varying temporal and spatial scales. The analyses of the adjacent beach’s contribution to tidal inlet sediment bypassing demonstrated variable temporal scales on sediment transport and exchange. High-energy wave events dominated the temporal scale for sand to be transported from the updrift beach to the ebb-tidal delta, whereas cyclical tidal processes had a significant influence on the spatial pattern of exchange between the shoals and channel features of the tidal inlet. The ability to simulate burial and erosion of tracers allowed identification of offshore sedimentation hotspots such as terminal lobe as well as zones of deposition and active transport in shallow water, such as the updrift channel margin linear bar and the downdrift platform of the ebb-tidal delta. The general sediment-bypassing pathway reflected a tidal-driven redistribution following event-driven pulses of wave-induced sediment mobilization. Sediment was transported along the beach during these energetic wave events. Flood- and ebb-tidal currents transported the sediment mobilized by high waves into the inlet channels. This was followed by subsequent gradual redistribution of the deposited channel sediments over the ebb-tidal delta features during fair-weather conditions. The modeling methods were then applied to investigate the sediment pathways and bypassing processes for three validated numerical models of coastal tidal inlets that span a range of forcing conditions. The processes that influence sediment transport along various pathways between the several morphological features of each inlet and its adjacent beaches were examined. The sediment tracing methodology employed in this study allowed for an evaluation of the sediment transport pathways between the various morphologic features of a tidal inlet, as well as their respective processes that drive the exchange of sediments. Characterizing and correlating the sediment pathways between tidal inlet morphologic features can improve the inlet reservoir model, which is a predictive model of inlet shoal volumes based on empirical formulae. The results of this study illustrate the value of including sediment-tracking techniques in simulating sediment bypassing and the potential of this application to inform coastal engineering and design modifications to sediment reservoirs of tidal inlets. And, finally, the spatial patterns of transport and erosion and deposition of traced, littoral source sediment, were investigated using the same modeling framework to evaluate the design of ebb-tidal delta mining on sediment bypassing dynamics of a tidal inlet system based on an idealized model of John’s Pass, Florida. Seven mining areas were simulated with traced sediment sources from the updrift beach, downdrift beach, and adjacent shoals. The tracers’ migration pattern and mining area infilling were analyzed to depict the sediment bypassing pathways and their contributions to mining area infilling. Mining area recovery rates were highest along the channel margin linear bar, and decrease offshore and downdrift. Updrift sand sources contributed more to mining area infilling than downdrift sand sources. The position of the mining area in relation to the updrift or downdrift morphological features dictates whether it will receive primarily updrift- or downdrift-originating littoral sediment from the beach. The source of sedimentation within the mining areas is a combination of inlet-ward transport of beach sediment and nearby shoal sediment. Proximity to the inlet channel determined the degree to which sedimentation had originated from longshore transported beach sediment. This methodology can improve confidence in management decisions concerned with the sand-sharing capacity of barrier-inlet systems in a local and regional context.

This thesis includes two research topics. The first topic is a low-power 2-dimensional bypassing digital multiplier design. The second one is a low-power sensorless micro-controller for brushless DC motors (BLDCM). The low-power 2-dimensional bypassing digital multiplier takes advantage of a 2-dimensional bypassing method. The proposed bypassing cells constituting the multiplier skip redundant signal transitions when the horizontally partial product or the vertically operand is zero. Hence, it is a 2-dimensional bypassing architecture. Thorough post-layout simulations show that the power dissipation of the proposed 8 ¡Ñ 8 design is reduced by more than 75% compared to the prior 8 ¡Ñ 8 design with obscure cost of delay and area. The goal of the low-power sensorless micro-controller for brushless DC motors is to design a BLDCM controller without using any Hall sensor. Back-EMF estimation method using the terminal voltage sensing is adopted for the detection of the commutation moment for the proper commutation control of the BLDCM. The position of the rotor can be precisely estimated by measuring the back-EMF as well as the zero-crossing points.

This thesis includes two topics. The first topic is an ADFS¡]All Digital Frequency Synthesizer¡^using a Flying Adder architecture. The second one is a low-power and low-latency 2-dimensional bypassing signed multiplier. In the first topic, the ADFS is implemented by only using the standard cell library of TSMC¡]Taiwan Semiconductor Manufacturing Company¡^0.18 £gm 1P6M CMOS process. The turn-around time is effectively reduced. Furthermore, the portability and reusability of the proposed design is significantly enhanced. The design provides stable clock signals with fast switching time. In the second topic, the proposed multiplier is carried out by Baugh-Wooley algorithm using 2-dimensional bypassing units. The proposed bypassing units automatically skip redundant signal transitions when either the horizontally¡]row¡^partial products or vertically¡]column¡^operands are zero.

Submitted by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2016-04-14T19:51:38Z No. of bitstreams: 1 Disse MP. Silvia Helena L. Rodrigues. 2015.pdf: 548263 bytes, checksum: 6d3ed80388e26635a912e50c92938c23 (MD5) / Approved for entry into archive by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2016-04-18T12:22:40Z (GMT) No. of bitstreams: 1 Disse MP. Silvia Helena L. Rodrigues. 2015.pdf: 548263 bytes, checksum: 6d3ed80388e26635a912e50c92938c23 (MD5) / Made available in DSpace on 2016-04-18T12:22:40Z (GMT). No. of bitstreams: 1 Disse MP. Silvia Helena L. Rodrigues. 2015.pdf: 548263 bytes, checksum: 6d3ed80388e26635a912e50c92938c23 (MD5) / As coagulopatias hereditárias são doenças hemorrágicas decorrentes da deficiência quantitativa/qualitativa de um ou mais fatores de coagulação sanguínea, sendo as hemofilias as mais importantes e frequentes. Os pacientes com hemofilia podem desenvolver anticorpos (inibidores) contra o fator deficiente, o que constitui em um desafio terapêutico. O tratamento das crises hemorrágicas em pacientes com inibidor é realizado com agentes bypassing. Este estudo é importante para se ampliar o conhecimento em base epidemiológica dos pacientes que utilizaram agentes bypassing possibilitando o aprimoramento da assistência prestada. Objetivo: Analisar o perfil de utilização dos agentes bypassing distribuídos pelo Ministério da Saúde durante os anos de 2012 e 2013. Metodologia: Trata-se de um estudo descritivo, transversal, de abordagem quantitativa, com base nos dados dos pacientes cadastrados no sistema Hemovida Web Coagulopatias, que utilizaram agentes bypassing nestes anos. Resultados: o perfil de utilização dos agentes bypassing é representado pelos pacientes na faixa etária até 29 anos (69,5%), ensino fundamental incompleto (23,8%), sexo masculino (83,8%), raça branca (43,6%), residentes na região sudeste (48,9%), com Hemofilia A (63%), forma grave da hemofilia (71%), presença de inibidor positiva (56,9%) e inibidor de altos títulos (60,5%). Embora tenha sido evidenciada a utilização off-label (2,8%) para o tratamento de coagulopatias não descritas na bula destes medicamentos. Considerações: Embora tenha sido evidenciado a utilização off-label, o perfil delineado está de acordo com os achados da literatura sobre os fatores associados ao desenvolvimento de inibidores, principal indicação de uso de agentes bypassing, e com as recomendações do Ministério da Saúde.

abstract: With the massive multithreading execution feature, graphics processing units (GPUs) have been widely deployed to accelerate general-purpose parallel workloads (GPGPUs). However, using GPUs to accelerate computation does not always gain good performance improvement. This is mainly due to three inefficiencies in modern GPU and system architectures. First, not all parallel threads have a uniform amount of workload to fully utilize GPU’s computation ability, leading to a sub-optimal performance problem, called warp criticality. To mitigate the degree of warp criticality, I propose a Criticality-Aware Warp Acceleration mechanism, called CAWA. CAWA predicts and accelerates the critical warp execution by allocating larger execution time slices and additional cache resources to the critical warp. The evaluation result shows that with CAWA, GPUs can achieve an average of 1.23x speedup. Second, the shared cache storage in GPUs is often insufficient to accommodate demands of the large number of concurrent threads. As a result, cache thrashing is commonly experienced in GPU’s cache memories, particularly in the L1 data caches. To alleviate the cache contention and thrashing problem, I develop an instruction aware Control Loop Based Adaptive Bypassing algorithm, called Ctrl-C. Ctrl-C learns the cache reuse behavior and bypasses a portion of memory requests with the help of feedback control loops. The evaluation result shows that Ctrl-C can effectively improve cache utilization in GPUs and achieve an average of 1.42x speedup for cache sensitive GPGPU workloads. Finally, GPU workloads and the co-located processes running on the host chip multiprocessor (CMP) in a heterogeneous system setup can contend for memory resources in multiple levels, resulting in significant performance degradation. To maximize the system throughput and balance the performance degradation of all co-located applications, I design a scalable performance degradation predictor specifically for heterogeneous systems, called HeteroPDP. HeteroPDP predicts the application execution time and schedules OpenCL workloads to run on different devices based on the optimization goal. The evaluation result shows HeteroPDP can improve the system fairness from 24% to 65% when an OpenCL application is co-located with other processes, and gain an additional 50% speedup compared with always offloading the OpenCL workload to GPUs. In summary, this dissertation aims to provide insights for the future microarchitecture and system architecture designs by identifying, analyzing, and addressing three critical performance problems in modern GPUs. / Dissertation/Thesis / Doctoral Dissertation Computer Engineering 2017

L'objectif de ce mémoire est de comprendre le fonctionnement hydro-sédimentaire des embouchures tidales dominées par la marée et la construction d'une flèche sableuse à crochets perpendiculaires. Deux sites voisins ont été choisis : les embouchures de l'Orne et de la Dives sur la côte du Calvados (Normandie). L'utilisation de données d'agitation et topographiques, acquises selon plusieurs échelles spatio-temporelles, permet d'étudier la morphodynamique de ces deux embouchures.L'embouchure de l'Orne possède une évolution soumise à une forte pression anthropique causée par de nombreuses infrastructures portuaires. Elle est comparée à celle de l'embouchure de la Dives, où l'impact anthropique est plus limité. Il apparaît que ces deux embouchures partagent les mêmes mécanismes de transports sédimentaires, avec une composante transversale importante. Ce transport vers la côte est assuré par la migration de barres de swash sur les parties aval-dérive des deltas de jusant. Ces barres de swash possèdent des volumes et des vitesses de migration similaires, comprises entre 3.5 et 8.0 m/mois.Contrairement à la Dives, les côtes en amont et en aval-dérive de l'embouchure de l'Orne sont en accrétion. Si en amont, cette accrétion suit les nombreuses phases de construction du port de Caen-Ouistreham, en aval se développe depuis un peu plus d'un siècle une flèche sableuse à la morphologie atypique. En effet, cette flèche possède plusieurs crochons emboités, dont les extrémités - les crochets - sont perpendiculaires au corps à la flèche. Il est démontré que l'attachement des barres de swash à la côte est responsable de la formation d'un nouveau crochon. La diffraction des vagues au niveau de l'extrémité des barres de swash et des crochons, ainsi que les directions locales de l'agitation, expliquent la formation des crochets perpendiculaires à l'extrémité des crochons. / The aim of this thesis is to understand the mechanisms of sediment bypassing at tidal inlets in a macrotidal environment and the formation of a sandspit with perpendicular hooks. Two closed areas are studied, the Orne and Dives inlets on the coast of Normandy (France). Wave and topographic data, at several space-time scales, are used to study the inlet morphodynamics.The Orne inlet is affected by strong human impacts due to several port facilities whereas the Dives inlet knows a limited anthropogenic impact. The study of the two inlets allows to deduce the impact of the human activities in the sediment transport patterns. The Orne and Dives inlets share the same mechanisms of sediment transport. Both show a major cross-shore component of the transport, underlines by the swash bars migration over the ebb-tidal deltas. All swash bars have similar volumes and migration rates, between 3.5 and 8.0 m/month.The Orne inlet shows deposition on both sides. The accretion on the updrift coast follows the building stages of the harbour of Caen-Ouistreham. On the downdrift coast, the deposition creates the Merville spit, which has several interlocked ridges. A perpendicular hook is present on the distal part of each ridge. This work shows that the swash bar attachment at the shoreline shapes a new ridge. Wave diffraction around the distal part of the swash bars and ridges, and the local wave directions, explain the formation of perpendicular hooks.

No description available.

Time-series aerial photographs from 1943 to 2006, including three bathymetry surveys from 1888, 1953, and 2006, are analyzed and compared. The locations of three morphological features, including that of shoreline, offshore bars, and channel orientation, are delineated over the historical aerial photos in order to examine the morphodynamics of the system. Anthropogenic alteration of the New Pass and Big Sarasota Pass system is a crucial factor in controlling the morphodynamics. Both New Pass and Big Sarasota Pass are mixed-energy tidal inlets with New Pass illustrating a straight morphology and Big Sarasota Pass a highly offset morphology. The sediment bypassing at New Pass can be explained by a modified ebb tidal delta breaching model with the breaching initiated by frequent channel dredging. The sediment bypassing at Big Sarasota Pass is different from that at New Pass, in that it is transported across the entire shallow ebb tidal delta with minor interruptions. This particular morphology, without a deep channel in the distal part of the ebb tidal delta, has been maintained by natural processes over at least the last 65 years. The shoreline in the vicinity of both inlets fluctuates as much as 200 m in a time scale of only few years. The advance and retreat of the shoreline at the southern tip of Lido Key is influenced by the frequent Lido Key beach nourishment. A large portion of the sediment is eventually transported onto the Big Sarasota Pass ebb tidal delta. The northern Siesta Key headland has experienced erosion since the 1960s. Downdrift of the headland, a persistent shoreline accretion was observed over the last 40 years, the pattern of which is related to the location and timing of the swash bar attachment.