Mechanistic-Empirical  (M-E)  pavement  design  procedures  are  composed  of  a  reliable  response model to estimate the state of stress in the pavement and distress models in order to predict the different types of pavement distresses due to the prevailing traffic and environmental conditions. One of the main objectives of this study was to develop a response model based on multilayer elastic  theory   (MLET)  with  improved  computational  performance  by   optimizing  the   time consuming parts of the MLET processes. A comprehensive comparison of the developed program with  two  widely  used  programs  demonstrated  excellent  agreement  and  improved  computational performance.  Moreover,  the  program  was  extended  to  incorporate  the  viscoelastic  behaviour  of bituminous materials through elastic-viscoelastic correspondence principle. A procedure based on collocation of linear viscoelastic (LVE) solutions at selected key time durations was also proposed that improved the computational performance for LVE analysis of stationary and moving loads. A comparison  of  the  LVE  responses  with  measurements  from  accelerated  pavement  testing  (APT) revealed a good agreement. Furthermore the developed response model was employed to evaluate permanent deformation models  for  bound  and  unbound  granular  materials  (UGMs)  using  full  scale  APTs.  The  M-E Pavement  Design  Guide  (MEPDG)  model  for  UGMs  and  two  relatively  new  models  were evaluated  to  model  the  permanent  deformation  in  UGMs.  Moreover,  for  bound  materials,  the simplified  form  of  the  MEPDG  model  for  bituminous  bound  layers  was  also  evaluated.  The measured  and  predicted  permanent  deformations  were  in  general  in  good  agreement,  with  only small discrepancies between the models. Finally, as heavy traffic loading is one of the main factors affecting the performance of flexible pavement, three types of characterizations for heavy traffic axle load spectrum for M-E analysis and design of pavement structures were evaluated. The study recommended an improved approach that enhanced the accuracy and computational performance. / <p>QC 20140512</p>

Automatic object detection is a challenging field which has been evolving over decades. The application areas span many domains such as robotics inspection, medical imaging, military targeting, and reconnaissance. Some of the most concentrated efforts in automatic object detection have been in the military domain, where most of the problems deal with automatic target detection and scene analysis in the outdoors using a variety of sensors. One of the critical problems in Automatic Target Detection (ATD) systems is multiscenario adaptation. Most of the ATD systems developed until today perform unpredictably i.e. perform well in certain scenarios, and poorly in others. Unless ATD systems can be made adaptable, their utility in battlefield missions remains questionable. This thesis describes a methodology that adapts parameterized ATD systems with image metrics as the scenario changes so that ATD system can maintain better performance. The methodology uses experimentally obtained performance models, which are functions of image metrics and system parameters, to optimize performance measures of the ATD system. Optimization is achieved by adapting system parameters with incoming image metrics based on performance models as the system works in field. A simple ATD system is also proposed in this work to describe and test the methodology.

Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.

Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.

Uma nova abordagem de sistema de gerência de pavimentos ferroviários é exposta nesta tese. O objetivo principal da pesquisa foi o desenvolvimento de um sistema de gerência em nível de rede e análises do custo do ciclo de vida em nível de projeto, adotando como estudo de caso a Estrada de Ferro Vitória Minas. A revisão bibliográfica apresenta modelos de avaliação da qualidade geométrica e estrutural no Brasil e no mundo. O desenvolvimento iniciou-se com a composição do sistema de gerência em nível de rede utilizando um inventário do trecho em estudo, a subdivisão dessa via em segmentos homogêneos de comprimento variável de acordo com a geometria (curva e tangente), e a aplicação de seis códigos: (i) classe de via; (ii) inventário da estrutura do pavimento com base no tipo de dormente; (iii) geometria com a definição da metodologia de avaliação da qualidade geométrica, propondo um índice que aplica o desvio padrão dos parâmetros geométricos (bitola, empeno, alinhamento e nivelamento transversal), a contagem de exceções e os respectivos limites de alerta, intervenção e segurança; (iv) superfície pela análise do desgaste do trilho e defeitos superficiais; (v) segurança pelo coeficiente de atrito; e (vi) capacidade estrutural com a aplicação do módulo de via parametrizado pelo carro controle. A partir dos seis códigos, foi possível categorizar a estratégia de manutenção aplicável e, em nível de projeto, foram analisadas as degradações do lastro e do desgaste do trilho, com definições de equações de predição, o que permitiu simular o custo do ciclo de vida das estratégias. Por fim, para verificar a viabilidade técnica da estratégia de manutenção apontada, foram estudadas as tensões no topo do lastro e do subleito e ainda o módulo de via por retro análise das deflexões medidas da via permanente em duas seções da EFVM. / A new approach to the railroad track management system is presented in this thesis. The main objective of the research was the development of a network management system and life cycle cost analysis in a project level, adopting as a case study of the Estrada de Ferro Vitoria Minas. The bibliographic review has exposed geometric and structural track quality evaluation models in Brazil and in the world. The development began with the composition of the network management system using an inventory of the track under study, the subdivision of the railway into homogeneous segments of variable lengths depending on the geometry (curve and tangent), and the application of six codes: (i) class, (ii) pavement structure inventory based on tie type, (iii) geometry with definition of quality assessment methodology proposing an index that applies the exception counting and the standard deviation of the parameters - cross level, warp, alignment and gauge - and safety, alarm and intervention limits, (iv) surface by analysis of rail wear and rail surface defects, (v) safety by friction coefficient, and (vi) structural capacity with the application of the track modulus parameterized by the track geometry car. From the six codes, it was possible to categorize the applicable maintenance strategy at a project level, create prediction equations of the ballast and the rail wear degradation and simulate life cycle cost of the strategies. In order to verify the technical feasibility of the mentioned maintenance strategy, it was measured the stress at the top of the ballast and subgrade and the track modulus by retroanalysis deflections in two sections of the EFVM.

Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.

Knowledge of the resource usage of applications and the resource usage capacity of hardware platforms is essential when developing a system. The resource usage must not over exceed the capacity of a platform, as it could otherwise fail to meet its real-time constraints due to resource shortages. Furthermore, it is beneficial from a cost-effectiveness stand-point that a hardware platform is not under-utilised by systems software. This thesis examines two systems aspects: the hardware resource usage of applications and the resource capacity of hardware platforms, defined as the capacity of each resource included in a hardware platform. Both of these systems aspects are investigated and modelled using a black box perspective since the focus is on observing the online usage and capacity. Investigating and modelling these two approaches is a crucial step towards defining and constructing hardware and software models. We evaluate regressive and auto-regressive modelling approaches of modelling CPU, L2 cache and L3 cache usage of applications. The conclusion is that first-order autoregressive and Multivariate Adaptive Regression Splines show promise of being able to model resource usage. The primary limitation of both modelling approaches is their inability to model resource usage when it is highly irregular. The capacity models of CPU, L2 and L3 cache derived by exerting heavy workloads onto a test platform shows to hold against a real-life application concerning L2 and L3 cache capacity. However, the CPU usage model underestimates the test platform's capacity since the real-life application over-exceeds the theoretical maximum usage defined by the model.

No description available.

In-service pavements require maintenance and rehabilitation (MandR) interventions to keep them in compliance with structural and functional standards. With the increased focus on the sustainability of our roadway systems, it has become important to document the cost and environmental impacts of different MandR strategies over the life cycle of the pavement to facilitate project selection decisions in the future. Asphalt pavement recycling, while cost-effective and environmentally friendly compared to other traditional MandR treatments, still faces some widespread implementation push-back, leading to policy enactments by the FHWA aimed at encouraging the use of recycling in road projects. Many agencies and contractors have cited the lack of project selection criteria, and uncertainty about long-term performance of these recycling alternatives as reasons impeding rapid implementation of these treatments in road projects. One of the gray areas of the FHWA's 2015 Recycled Material Policy in project selection was, until recently, the lack of guidelines or tools for the assessment of the environmental suitability of candidate MandR treatments. Today, it is almost impossible to evaluate the environmental suitability of various recycling-based end-of-service-life treatments because available databases do not have relevant information on the details of unit processes, construction equipment and activities, and use-stage roughness data. Development of future MandR plans throughout the service life of pavements rehabilitated with recycling-based treatments is somewhat limited as deterioration is not fully understood. Also, available modeling tools no not address all LCA phases, or in cases where they do, key life cycle phases including the MandR, and use phases are not well covered due to the lack of quantification highlighted earlier. To address the highlighted concerns, this dissertation developed a user-friendly comprehensive LCA tool that was further validated with a case study to quantify the service life (when the pavement has reached a critical threshold performance value) and potential environmental benefits of pavement recycling projects executed by the Virginia Department of Transportation over the past decade. The tool, pySuPave, includes an excel spreadsheet user-inputs interface, and database of economic flows for unit processes used in the production of pavement materials and subsequent construction of the pavement system, considering transportation of materials and construction machinery to plants and construction site. A python-based program was used to perform matrix-based computations to generate the environmental burdens from the available public LCA Ecoinvent database. A substantive part of the dissertation was dedicated to evaluating the performance of in-service pavements rehabilitated with cold recycling and full-depth reclamation treatments, focusing on developing pavement performance prediction models (PPPM) that goes on to improve modelling of the MandR and use stages in the pavement LCA and ultimately bridges the knowledge gap on how these treatments perform in the long term. This part of the dissertation was presented in two chapters; trends in pavement recycling and performance data collection, and development of PPPMs for recycled asphalt pavements. The first provides an update and examines the current state of pavement recycling techniques, highlighting trends in the various recycling methods, examining what is and is not working from the agency perspective, and assessing the progress made in the last decade through a web-based survey. The survey results did not indicate significant changes in the adoption of the asphalt pavement recycling concept in the last decade. However, recycling techniques, such as hot in-place recycling, are being used less and more agencies seem to be adopting lower temperature techniques such as cold in-place recycling, cold central plant recycling and full depth reclamation. Improvements in mix design methods were noticeable, as more agencies have adopted contemporary methods, such as the Superpave design. Among states, very few agencies collected performance data for completed asphalt pavement recycling projects. The second chapter on performance focused on developing individual and family-type PPPMs from the data collected from the states of Virginia and Colorado, respectively. While regression modeling forms the backbone of the approach used, the chapter also presents an approach to developing family-type models using functional data analysis to find groups of projects with similar deterioration trends. In the case of Colorado, cold in-place recycling (CIR) projects completed with an initial IRI between 71 and 91 in/mi are most likely to deteriorate at an average group rate of 1.37 in/mi/year. Similarly, full depth reclamation (FDR) projects will most likely deteriorate following an average group rate of 1.40 in/mi/yr, with an initial IRI between 52 and 70 in/mi. These projects will stay in service well over 30 years if a threshold IRI of 140 in/mi were used a failure criterion. For the individual roughness models developed for VDOT, the initial IRI values and the rate of change for the treatments analyzed were found to range between 48 and 85 in/mi and between 0.70 and 5.20 in/mi/year, respectively, depending on the recycling method and type of stabilization treatment. Finally, a context-based life cycle assessment case study was conducted to benchmark and compare the environmental impacts associated with rehabilitating a low-volume road with various recycled-based and equivalent conventional methods. Several impact indicators were assessed but only the global warming (GW) score and the single score index that combines all the environmental impact indicators into a single number using normalization and weighting factors were reported in this study for the sake of brevity. Four restorative maintenance projects including two CIR (4-in. HMA over a 5-in. CIR with foamed asphalt and emulsion stabilization), one cold central plant recycling (CCPR): 4-in. HMA over a 5-in. foamed asphalt CCPR (CCPR FA), and one non-recycling structural overlay (8-in. HMA over an existing pavement) were evaluated. In addition, the following reconstruction projects were assessed; two FDR (4-in. HMA over a 12-in. FDR with foamed asphalt with 1% cement additive, and a 4-in. HMA over 10.5-in. cement stabilized FDR), and a non-recycling reconstruction project (a new reconstruction project with 8-in. HMA over a 16-in. aggregate base and subbase). The functional unit was a two lane-mile length, 12 feet wide project with a traffic volume of 1000 vehicles (3% trucks) and the analysis was conducted for 50 years. The GW score and a few other impact indicators showed an increase in the observed results where cement is used as a main stabilizer or as an additive. Between the asphalt stabilized projects, the difference in impact scores is only seen when cement is used as an additive as highlighted in the case of foamed asphalt applications. Even for the low-volume road under study, the use stage contributes the largest share to global warming and is—among several factors—attributed to the initial surface roughness of completed projects. Thus, for state DOTs looking to reduce the environmental footprints for road infrastructure projects and achieve federal legislative goals, building smoother roads and taking steps to keep the annual deterioration rate low would be an important measure, in addition to pavement recycling. Comparing the projects based on the overall single score derived from weighting factors from the National Institute of Standards and Technology (NIST) ranks the projects as follows (listed in order decreasing impacts per rehabilitation category); restorative maintenance projects: T. OVERLAY (non-recycling structural overlay—8 in. HMA over an existing pavement) - 1.06 pts, CCPR FA (4 in. HMA over a 5 in. cold central plant recycling with foamed asphalt) - 1.02 pts, CIR FA (4 in. HMA over a 5 in. cold in-place recycling with foamed asphalt) - 1.00 pts, CIR AE (4 in. HMA over a 5 in. cold in-place recycling with emulsion)- 0.86 pts; reconstruction projects: RECONS (a new reconstruction project—8 in. HMA over a 16 in. aggregate base and subbase) -1.42 pts, FDR FA+C (4 in. HMA over a 12 in. FDR with foamed asphalt with 1% cement additive) - 1.15 pts, FDR C (4 in. HMA over 10.5 in. cement stabilized FDR) - 1.02 pts. / Doctor of Philosophy / Due to harsh environmental conditions and continual damage from moving traffic, highway pavements or roadways deteriorate and grow weak over time. Throughout their life in service, different maintenance and rehabilitation (MandR) activities are performed with the intention of slowing down the deterioration to always keep the highway at a certain level of service to road users. For a long time, these MandR activities have included the use of virgin materials in techniques ranging from minor treatment applications such as fog seals, chip seals, thin overlays through more heavy treatments such as mill and fills, thicker overlays all the way to total reconstruction. Other MandR alternatives include pavement recycling which reuses materials from the existing distressed roadways either in-place or at a nearby mobile plant have gained popularity among several state highway agencies over the last decade. The advantages of using the recycling alternatives compared to non-recycling options are many and have been known to include cost savings, less construction time, and low environmental footprint. Many highway agencies, however, have expressed the lack of information on project selection criteria and the uncertainty about long-term performance of these recycling alternatives as reasons impeding rapid and widespread implementation in road projects. Agencies need selection criteria to help them identify the right treatments to apply to the right road at the right time. In a bid to encourage the use of pavement recycling treatments, the Federal Highway Administration (FHWA) enacted the Recycled Materials Policy in 2006 (revised 2015) but the policy did not fully address certain aspects of project selection. Directives on assessing the environmental suitability of recycling projects, for instance, was not given. There are no tools with modern databases incorporating the various unit processes for pavement recycling to aid agencies carry out this environmental assessment. To address the highlighted concerns, we developed a user-friendly comprehensive environmental assessment tool called pySuPave as part of this dissertation. We later validated the tool with a case study to quantify the potential environmental benefits of pavement recycling projects executed by the Virginia Department of Transportation over the past decade. Next, we conducted a survey of the departments of transportation (DOT) around the United States and Canada to collect performance data from agencies with active in-place recycling programs. Approximately 18% of the DOTs surveyed were able to provide performance data. Data received from Colorado and Virginia were subsequently used to developed models to predict deterioration in recycled pavements. In the case of Colorado, CIR projects completed with an initial roughness (IRI) between 71 and 91 in/mi are most likely to deteriorate at a rate of 1.37 in/mi/year. Similarly, FDR projects will most likely deteriorate following an average group rate of 1.40 in/mi/yr, with an initial IRI between 52 and 70 in/mi. These projects will stay in service well over 30 years if a threshold IRI of 140 in/mi were used a failure criterion. For the individual roughness models developed for VDOT, the initial IRI values and the rate of change for the treatments analyzed were found to range between 48 and 85 in/mi and between 0.70 and 5.20 in/mi/year, respectively, depending on the recycling method and type of stabilization treatment Finally, we conducted an environmental assessment case study to benchmark and compare the environmental burdens i.e., global warming (GW) and other impacts associated with rehabilitating a low-volume road with various recycled-based and equivalent non-recycling methods. Four restorative maintenance projects including two CIR (4-in. HMA over a 5-in. CIR with foamed asphalt and emulsion stabilization), one CCPR (4-in. HMA over a 5-in. foamed asphalt CCPR [CCPR FA]), and one non-recycling structural overlay (8-in. HMA over an existing pavement) were evaluate. In addition, the following reconstruction projects were assessed; two FDR (4-in. HMA over a 12-in. FDR with foamed asphalt with 1% cement additive, and a 4-in. HMA over 10.5-in. cement stabilized FDR), and a non-recycling reconstruction project (a new reconstruction project with 8-in. HMA over a 16-in. aggregate base and subbase). The functional unit was a two lane-mile length, 12 feet wide project with a traffic volume of 1000 vehicles (3% trucks) and the analysis was conducted for 50 years. The study results showed that the recycling-based projects had lower overall environmental burdens compared to their equivalent non-recycling alternatives. The GW score and a few other environmental impact indicators were higher when cement is used as a main stabilizer or as an additive in the recycling projects. Between the asphalt stabilized recycling projects, the difference in impact scores is only seen when cement is used as an additive as emphasized in the case of foamed asphalt applications. Even for the low-volume roads under study, the use stage (when the project is open to road-users) in the pavement life cycle contributes the largest share to global warming and is—among several factors—attributed to the initial surface roughness of completed projects. Thus, for state DOTs looking to reduce the environmental footprints for road infrastructure projects and achieve federal legislative goals, building smoother roads and taking steps to keep the annual deterioration rate low would be an important measure, in addition to pavement recycling. The results from this research support the hypothesis that pavement recycling can reduce global warming and other environmental burdens compared to non-recycling methods. Therefore, agencies should encourage more pavement recycling programs.

L'accélération matérielle désigne l'utilisation d'architectures spécialisées pour effectuer certaines tâches plus vite ou plus efficacement que sur du matériel générique. Les accélérateurs ont traditionnellement été utilisés dans des environnements contraints en ressources, comme les systèmes embarqués. Cependant, avec la fin des règles empiriques ayant régi la conception de matériel pendant des décennies, ces quinze dernières années ont vu leur apparition dans les centres de calcul et des environnements de calcul haute performance. Les FPGAs constituent une plateforme d'implémentation commode pour de tels accélérateurs, autorisant des compromis subtils entre débit/latence, surface, énergie, précision, etc. Cependant, identifier de bons compromis représente un défi, dans la mesure où l'espace de recherche est généralement très large. Cette thèse propose des techniques de conception pour résoudre ce problème. Premièrement, nous nous intéressons aux compromis entre performance et précision pour la conversion flottant vers fixe. L'utilisation de l'arithmétique en virgule fixe au lieu de l'arithmétique flottante est un moyen efficace de réduire l'utilisation de ressources matérielles, mais affecte la précision des résultats. La validité d'une implémentation en virgule fixe peut être évaluée avec des simulations, ou en dérivant des modèles de précision analytiques de l'algorithme traité. Comparées aux approches simulatoires, les méthodes analytiques permettent une exploration plus exhaustive de l'espace de recherche, autorisant ainsi l'identification de solutions potentiellement meilleures. Malheureusement, elles ne sont applicables qu'à un jeu limité d'algorithmes. Dans la première moitié de cette thèse, nous étendons ces techniques à des filtres linéaires multi-dimensionnels, comme des algorithmes de traitement d'image. Notre méthode est implémentée comme une analyse statique basée sur des techniques de compilation polyédrique. Elle est validée en la comparant à des simulations sur des données réelles. Dans la seconde partie de cette thèse, on se concentre sur les stencils itératifs. Les stencils forment un motif de calcul émergeant naturellement dans de nombreux algorithmes utilisés en calcul scientifique ou dans l'embarqué. À cause de cette diversité, il n'existe pas de meilleure architecture pour les stencils de façon générale : chaque algorithme possède des caractéristiques uniques (intensité des calculs, nombre de dépendances) et chaque application possède des contraintes de performance spécifiques. Pour surmonter ces difficultés, nous proposons une famille d'architectures pour stencils. Nous offrons des paramètres de conception soigneusement choisis ainsi que des modèles analytiques simples pour guider l'exploration. Notre architecture est implémentée sous la forme d'un flot de génération de code HLS, et ses performances sont mesurées sur la carte. Comme les résultats le démontrent, nos modèles permettent d'identifier les solutions les plus intéressantes pour chaque cas d'utilisation. / Hardware acceleration is the use of custom hardware architectures to perform some computations faster or more efficiently than on general-purpose hardware. Accelerators have traditionally been used mostly in resource-constrained environments, such as embedded systems, where resource-efficiency was paramount. Over the last fifteen years, with the end of empirical scaling laws, they also made their way to datacenters and High-Performance Computing environments. FPGAs constitute a convenient implementation platform for such accelerators, allowing subtle, application-specific trade-offs between all performance metrics (throughput/latency, area, energy, accuracy, etc.) However, identifying good trade-offs is a challenging task, as the design space is usually extremely large. This thesis proposes design methodologies to address this problem. First, we focus on performance-accuracy trade-offs in the context of floating-point to fixed-point conversion. Usage of fixed-point arithmetic instead of floating-point is an affective way to reduce hardware resource usage, but comes at a price in numerical accuracy. The validity of a fixed-point implementation can be assessed using either numerical simulations, or with analytical models derived from the algorithm. Compared to simulation-based methods, analytical approaches enable more exhaustive design space exploration and can thus increase the quality of the final architecture. However, their are currently only applicable to limited sets of algorithms. In the first part of this thesis, we extend such techniques to multi-dimensional linear filters, such as image processing kernels. Our technique is implemented as a source-level analysis using techniques from the polyhedral compilation toolset, and validated against simulations with real-world input. In the second part of this thesis, we focus on iterative stencil computations, a naturally-arising pattern found in many scientific and embedded applications. Because of this diversity, there is no single best architecture for stencils: each algorithm has unique computational features (update formula, dependences) and each application has different performance constraints/requirements. To address this problem, we propose a family of hardware accelerators for stencils, featuring carefully-chosen design knobs, along with simple performance models to drive the exploration. Our architecture is implemented as an HLS-optimized code generation flow, and performance is measured with actual execution on the board. We show that these models can be used to identify the most interesting design points for each use case.