Дисертації з теми "Trigger Processor"

Le modèle standard de la physique des particules représente le point culminant de la compréhension humaine en termes de blocs de construction fondamentaux de l'univers et de leur interaction à un niveau fondamental. Pourtant, il lui manque encore plusieurs pièces, comme les solutions au problème de la hiérarchie de jauge, les mécanismes à l'origine des masses des neutrinos et les candidats à la matière noire, qui nécessitent tous une nouvelle physique et des théories au-delà du modèle standard (BSM). Repousser ces frontières implique une amélioration constante des capacités expérimentales et de la compréhension théorique de la communauté scientifique de la physique des particules à haute énergie (HEPP). Si la dernière percée sur ce front remonte sans doute à une décennie avec la découverte du boson de Higgs, ces dix dernières années ont été marquées par une croissance explosive en termes de développement technologique dans le domaine du calcul scientifique, tant du point de vue matériel que logiciel. Les méthodes d'apprentissage automatique (ML) ont été largement adoptées et ont connu un grand succès dans de nombreux domaines, grâce à l'accélération matérielle de plus en plus performante des unités de traitement graphique (GPU). Cette recherche de doctorat vise à étudier l'efficacité potentielle de l'application de mises en œuvre de réseaux neuronaux (NN) pour améliorer différents domaines de HEPP. Du côté des détecteurs, je me suis concentré sur l'évaluation de la faisabilité du déclenchement au niveau hardware pour le détecteur de muons ATLAS "New Small Wheel" (NSW) récemment installé. Le processeur de déclenchement (TP) fonctionne in situ sur du hardware FPGA (Field-Programmable Gate Array) avec un budget temps de 200 ns pour prendre une décision de déclenchement de niveau 0 (L0). Il s'agit d'exigences très strictes et, compte tenu du fait que l'inférence NN est gourmande en ressources, le modèle a été conçu spécifiquement pour atténuer ces limitations inhérentes. En fin de compte, une approche de réseau neuronal convolutif (CNN) a été choisie pour interpréter les résultats des huit plans de détection MicroMegas (MM) du NGS et entraînée à produire des quantités liées à la probabilité qu'une piste de muons provienne du point d'interaction (IP). Le second sujet principal de cette thèse concerne l'exploration de l'apprentissage non supervisé comme moyen de recherche de BSM agnostique. En ayant accès aux données générées par des processus SM bien compris, un NN est entraîné à comprimer les événements dans une représentation de plus faible dimension et à l'utiliser pour reconstruire l'entrée originale. Ce type de modèle est appelé Autoencodeur (AE), et une erreur élevée de reconstruction d'un événement est un indicateur potentiel que l'événement ne fait pas partie de la même distribution que les données d'apprentissage.de la même distribution que les données d'apprentissage, à savoir les données SM. La combinaison d'un tel modèle avec l'estimation de densité basée sur les réseaux neuronaux donne un ensemble appelé autoencodeur probabiliste (PAE), qui représente la technique centrale employée dans cette recherche. Le PAE a été testé en tant qu'outil potentiel pour identifier une nouvelle physique de manière indépendante du modèle dans le contexte de la physique des jets et a donné des résultats prometteurs
The Standard Model of particle physics represents the culmination of human understanding in terms of the fundamental building blocks of the universe and how they interact at a fundamental level. Yet, it is still missing several pieces such as solutions for the gauge hierarchy problem, and the mechanisms behind neutrino masses and dark matter candidates, all of which require new physics and Beyond Standard Model (BSM) theories. Pushing those frontiers implies constant improvements both in the experimental capabilities and theoretical understanding of the High-Energy Particle Physics (HEPP) scientific community. While the last breakthrough on this front was arguably one decade ago with thediscovery of the Higgs boson, those last 10 years brought explosive growth in terms of technological development in scientific computation, both on the hardware and software side. Machine Learning (ML) methods have seen widespread adoption and success across many fields, aided by the increasingly better performing Graphics Processing Unit (GPU) hardware acceleration. This Ph.D. research aims to study the potential effectiveness of applying Neural Network (NN) implementations to improve different areas of HEPP. On the detector side, I focused on evaluating the feasibility of hardware-level trigger for the newly installed ATLAS New Small Wheel (NSW) end-cap muon detector. The Trigger Processor (TP) operates in-situ on Field-Programmable Gate Array (FPGA) hardware within a 200 ns time budget allowed for making a Level-0 (L0) trigger decision. Those are very stringent requirements and considering how resource-hungry NN-inference is, the model was designed specifically to mitigate those inherent limitations. In the end, a Convolutional Neural Network (CNN) approach was chosen to interpret hits from the NSW’s eight MicroMegas (MM) detector planes and trained to output quantities related to the likelihood for a muon track to originate from the interaction point (IP). The second main topic of this thesis involves the exploration of unsupervised learning as a means to model-agnostic BSM searches. Provided access to data generated by well-understood SM processes, a NN is trained to compress the events into a lower-dimensional representation and use it to reconstruct the original input. This type of model is called Autoencoder (AE), and a high error of an event’s reconstruction is a potential indicator that the event is not partof the same distribution as the training data, namely SM data. Combining such a model with NN-based density estimation results in an ensemble called Probabilistic Autoencoder (PAE) and this represented the central technique employed in this research. The PAE was tested as a potential tool for identifying new physics in a model-independent way in the context of jet physics and showed promising results

This thesis investigates the reconstruction of Z(→ee)γ events with the ATLAS detector at the LHC. The capabilities of the detector are explored for the initial run scenario with a proton-proton centre of mass collision energy of √s = 7TeV, and an integrated luminosity of \(\char{cmsy10}{0x4C}\) = 1 fb⁻¹. Monte Carlo simulations are used to predict the expected precision of a differential cross-section measurement for initial state radiation Z + γ events, both with respect to the transverse momentum of the photon, p_T(γ), and the three body eeγ invariant mass. A bin-by-bin correction is used to account for the signal selection efficiency and purity, and to correct the measured (simulated) distribution back to the theoretical prediction. The main backgrounds are found to be from the final state radiation Z + γ process, and from jets faking photons in Z → ee events. The possible QCD multijet background is studied using a fake-rate method, and found to be negligible for the particle identification cuts used in the analysis. The main systematic uncertainties on the differential cross-section measurements are explored with Monte Carlo simulations, and found to be of a similar scale to the statistical errors for the chosen distribution binning. The three body eeγ invariant mass distribution was then used as the basis of an exclusion study on new particles decaying to the Z(ee)γ final state. Under the assumption that the measured data agrees with the Standard Model prediction, exclusion limits were placed at 95% confidence level on the cross-section times branching ratio for a new scalar (modelled by SM Higgs process), or vector (based on a low-scale technicolor process) particle hypothesis, for particles in the mass range 200 to 900GeV. Limits of the order \(\char{cmsy10}{0x4f}\)(0.01) - \(\char{cmsy10}{0x4f}\)(0.1) pb on the cross section times branching ratios are predicted, which would improve on the equivalent limits previously calculated by the DØ experiment at the Tevatron collider, albeit in a different √s region, where cross-sections will generally be higher for new massive particles. In addition to the Zγ measurements, a digital timing calibration procedure was developed for the Cluster Processor (CP) subsystem of the level-1 calorimeter trigger. This work was essential to providing a repeatable and robust mechanism for timing in the digital processing in the CP system, a necessary ingredient for a robust and reliable trigger system; a pre-requisite of any physics analysis. This calibration procedure is described here.

The objective of the research presented in this thesis is to investigate alternative ways of information processing employing asynchronous, data driven, and analogue computation in massively parallel cellular processor arrays, with applications in machine vision and artificial intelligence. The use of cellular processor architectures, with only local neighbourhood connectivity, is considered in VLSI realisations of the trigger-wave propagation in binary image processing, and in Bayesian inference. Design issues, critical in terms of the computational precision and system performance, are extensively analysed, accounting for the non-ideal operation of MOS devices caused by the second order effects, noise and parameter mismatch. In particular, CMOS hardware solutions for two specific tasks: binary image skeletonization and sum-product algorithm for belief propagation in factor graphs, are considered, targeting efficient design in terms of the processing speed, power, area, and computational precision. The major contributions of this research are in the area of continuous-time and discrete-time CMOS circuit design, with applications in moderate precision analogue and asynchronous computation, accounting for parameter variability. Various analogue and digital circuit realisations, operating in the continuous-time and discrete-time domains, are analysed in theory and verified using combined Matlab-Hspice simulations, providing a versatile framework suitable for custom specific analyses, verification and optimisation of the designed systems. Novel solutions, exhibiting reduced impact of parameter variability on the circuit operation, are presented and applied in the designs of the arithmetic circuits for matrix-vector operations and in the data driven asynchronous processor arrays for binary image processing. Several mismatch optimisation techniques are demonstrated, based on the use of switched-current approach in the design of current-mode Gilbert multiplier circuit, novel biasing scheme in the design of tunable delay gates, and averaging technique applied to the analogue continuous-time circuits realisations of Bayesian networks. The most promising circuit solutions were implemented on the PPATC test chip, fabricated in a standard 90 nm CMOS process, and verified in experiments.

This dissertation, comprised of the cover story and the four separate but interrelated articles, focuses on exploring the development of entrepreneurial competence. Building on the assumption that purposeful engagement in entrepreneurial action potentially leads to the acquisition of specific entrepreneurial competencies, this thesis investigates the mechanisms facilitating and enabling entrepreneurs’ acquisition of entrepreneurial expertise, and the consequences of this process. As such, it unpacks the entrepreneurial learning process. In particular, building on Bandura’s (1986) social  cognitive theory (SCT), this study explores the role of deeply held beliefs, goal orientation and social networks (role models) in shaping entrepreneurs’ behavior, specifically their ability to create new means-ends frameworks (cf. Sarasvathy, 2001). The research included in this dissertation provides insight into the complexity of entrepreneurial competence development by connecting multiple theoretical perspectives, utilizing two different qualitative datasets situated in the context of gourmet restaurateurs and abductively building theory by developing explanations of the phenomenon of interest. This is one of the first attempts to open the ‘black box’ of entrepreneurial learning by simultaneously incorporating the contextual variables and the cognitive properties and practices of entrepreneurs in exploring their learning process. By combining SCT with entrepreneurship theory, the thesis develops an integrating model of entrepreneurial competence development that explains the relation between the preferred learning mode, action-control beliefs, the perceived role identity and role models. The findings suggest that attainment of entrepreneurial competence, and ultimately expertise, is facilitated by changes in action-control beliefs; and by the development of entrepreneurial identity. The findings also suggest that the role model’s perceived function changes depending on the entrepreneur’s goal orientation. Thus, one of the most important implications of the study is the idea that entrepreneurs need to become agents of their own development. Overall, this dissertation provides an explanation of the mechanisms of entrepreneurial competence development by suggesting that changing action-control beliefs and the formation of entrepreneurial identity are crucial in the development of entrepreneurial competence. In addition, access to role models and learning goal orientation facilitate this process.

Individuals within a single population can vary widely in their phenotype e.g. in their body shape. These differences are an important source of biodiversity and they can precede evolutionary divergence within a population. In this thesis we use the biological invasion of the zebra mussels into Swedish lakes to investigate which processes create or maintain phenotypic diversity within populations of the two native fish species perch and roach and the mussel itself. Both fishes have specially adapted body shapes that depend on whether they feed in the near-shore or open-water habitat of lakes. This habitat-specific divergence was more pronounced in lakes with zebra mussels, probably because resources in both habitats were in higher supply due to the mussels’ effects on the lakes. Divergence in perch body shapes between habitats was also higher in lakes with a higher water clarity, suggesting that visual conditions can affect the resource use and thus also the expression of a habitat-specific body shape. When investigating the diversity of body shapes in the mussel itself we found that mussels from one lake changed their shell shape when exposed to different predators: fish predators induced a more elongated shell shape while crayfish predators induced a rounder shell. These specific shell shapes probably serve as two alternative predator defenses protecting the mussel from predation. We conclude that the availability and use of distinct resources is an important source of diversity within populations. Abiotic conditions can play a previously underappreciated role by promoting or impairing the use of the distinct resources thus affecting the divergence. The diversity of shell shapes we found in the zebra mussels complements our study by demonstrating that not only consumer responses to resources but also resources’ responses to predators can generate phenotypic diversity.

V této práci je navrhnut energeticky úsporný procesor typu TTA (Transport Triggered Architecture) pro výpočet rychlé Fourierovy transformace (FFT). Návrh procesoru byl vytvořen na míru použitému algoritmu pomocí speciáoních funkčních jednotek. Algoritmus byl realizován jako posloupnost instrukcí tak, že většina výpočtu probíhá ve smyčce obrahující pouze jedionu paralelní instrukci. Tato instrukce je umístěna do instrukčního bufferu, odkud je potom volána místo instrukční paměti. Díky tomu se dá docílit nižší spotřeby, neboť volání z instrukčního bufferu je efektivnější než volání z instrukční paměti. Program byl zkompilován na časovém modelu procesoru a časová simulace potvrdila správnost návrhu. Součástí práce jsou rovněž pomocné programy v Pythonu, které slouží ke generaci referenčních výsledků a automatické simulaci a porovnání výsledků simulace s referencí.

A utilização dos apalpadores acoplados a máquinas CNC se tornou uma realidade muito comum no mundo atual, principalmente devido à diminuição do tempo de preparação e possibilidades de realização de medições na própria máquina-ferramenta. Porém, ainda existem algumas barreiras a se transpor, como por exemplo, a dificuldade de programação, custo relativamente elevado e pouca literatura que trata exclusivamente a respeito da utilização dos apalpadores para medição nas máquinas-ferramentas. Nesse trabalho é realizada uma revisão bibliográfica sobre o uso dos apalpadores em ambiente industrial, discutindo-se as tecnologias utilizadas na geração do sinal de \"trigger\" e é proposto um novo modelo de apalpador de contato elétrico, de baixo custo, desenvolvido especialmente para atender as necessidades de medições em tornos CNC. Os testes em laboratório revelaram que a repetibilidade do protótipo construído foi de 0,003 mm dentro de uma confiabilidade de mais ou menos 3 \'sigma\' ou 99,73%. Concluiu-se que tais características são altamente compatíveis com os requisitos necessários para a maioria dos processos de torneamento.
The use of touch trigger probes attached to CNC machines has become a world standard, especially due the reduction of setup time and the ability to promote work piece measurements on machine. However, some barriers like measurement routines programming difficulties, high costs of these equipments and the low number of technical literature about this subject, still need to be transposed. This work presents a review on the applications of touch trigger probes on companies shop floor, discussing the nowadays technologies used to generate the trigger signal. A new touch trigger probe model based on a simple electrical contact is specially developed to provide the measuring characteristics required for Lathes, with the needed characteristics and low cost. The tests of the probe developed in the laboratory shown a repeatability of 0,003 mm (more and less 3 \'sigma\' or 99,73%). Those characteristics are high compatible with the most needs of the industry.

Ever evolving wireless communication standards, reduced time-to-market and a need for flexibility and interoperability of multiple wireless communication technologies on a single device are the driving factors behind implementation of wireless standards on Software Defined Radios (SDR) platforms. The concept behind SDR is to implement as much functionality on software as possible. SDR provide greater interoperability and programmability compared with traditional hardwired implementation at the cost of higher power consumption and market cost. SDR is the driving technology for the next generation of co-operative and cognitive radios. For implementing an SDR, the existing wireless communication algorithms needs to be modified and an appropriate hardware platform needs to be selected. The IEEE 802.15.4 LR-WPAN standard requires low cost and low-power consuming devices. The data rate requirements are also low (such as 250 kbps). Traditionally, the devices compliant with the standard are hardwired system-on-chip implementation which provides benefit in terms of power and cost. Recently, there has been significant effort on modeling the IEEE 802.15.4 SDR systems which provide greater interoperability and programmability of the devices. In this study, Transport Triggered Architecture (TTA) based Application Specific Processor is selected for SDR implementation of the IEEE 802.15.4 2.4 GHz physical layer for studying the performance of such system in terms of Bit-Error-Rate, CPU cycle count, and processor chip area. As part of this work, different SDR frameworks like GNU Radio, Matlab-Simulink etc. were evaluated for their feasibility of providing an agile platform for the development. These existing frameworks need an operating system for their execution and are not suitable for stand-alone systems such as a TTA based processor. The work also includes the study of different receiver algorithms and design choices for the transceiver implementation. Based on existing literature and Matlab modeling, Asynchronous Zero-Crossing Detector (AZCD) based non-coherent receiver algorithm is selected for the implementation. The algorithm provides the required BER performance with very less complex computation and is suited for low power and low chip area implementations. The transmitter and receiver are implemented on single-core TTA processors which provide the required performance in terms of BER and data throughput. The processors designed need a very low silicon area and clock frequency for their realization.

Esta dissertação caracteriza-se como memorial reflexivo de uma pesquisa empírica, que se enquadra no campo de estudos dos processos de criação cênica. A pesquisa se articula em torno da questão da imersão na cena contemporânea, aqui despertada pelo contato com obras que têm como denominador comum a relação intrínseca da cena e da tecnologia e, ao mesmo tempo, investem na experiência de inundamento sensorial de seus espectadores. A partir dessa perspectiva, investigo procedimentos que possam promover essa experiência teatral imersiva. Para isso, desenvolvo uma pesquisa em dois módulos. O primeiro, um estudo bibliográfico, que visa reconhecer tensões conceituais sobre a perspectiva da imersão. Neste reconheço os princípios de provocação do efeito imersão para serem aplicados no segundo módulo da pesquisa. O segundo módulo dedico à investigação empírica por meio do agenciamento de um experimento cênico conduzido pelos disparadores de imersão discriminados nos desdobramentos teóricos. Esses desvendados por articulação de dispositivos tecnológicos com elementos da linguagem teatral: tempo, espaço, presença, dimensão real e ficcional e manipulação dos sentidos. A partir dessa premissa, desenvolvi o experimento cênico “Insônia”. Disseco o processo de criação e, por consequência, problematizo as descobertas e soluções cênicas encontradas no caminho.
This dissertation distinguishes as a memorial of an empirical research, that belongs to the research field of theatrical creation processes. This research revolve around the notion of immersion in the contemporary scene. In this work is considered by recent contact with theater plays that makes uses of technology and bets in the experience of sensory flooding the spectators. From this perspective, i develop a research about the procedures that might produce this immersive theatrical experience. For achieving that I divide this work in two modules. The first module, a bibliographical study, that wishes to recognize conceptual tensions about the notion of immersion. Here I recognize the principles of provoking this immersion effect for then applying in the second module of the research. In the second module I devote to the empirical research by the means of arranging a theatrical experiment conducted by the immersion triggers found in the conceptual studies. These were discovered by linking technological devices and elements of theatre language: time, space, presence, real and fictional dimensions and sense manipulation. Having this as premise, I developed the theatrical experiment called “Insônia”. I analyze the creative processes and problematize the discoveries and scenic solutions found along the way.

Embedded processors play a key role in many safety-critical applications including medical, automotive and aerospace systems. In such systems an inability to provide guarantees that the design will meet its requirements can have catastrophic consequences. To ensure that guarantees can be made, it must be possible to predict both the functional and temporal properties of the system at design time. The trend in modern embedded system design is currently leading towards unpredictable processor architectures in order to achieve increased performance. This trend presents fundamental challenges for the designers of timing analysis tools who are finding the accuracy and safety of timing estimations produced by new tools are getting worse. The consequence of this is that it is increasingly becoming harder to provide guarantees that the system requirements will be met. The primary causal factor is put down to the developments in modern processor architecture. This thesis attempts to address these problems with a novel, highly predictable embedded processor design for systems with a “time-triggered” (TT) system architecture. Even with a predictable processor, a real-time operating system (RTOS) implemented in software can itself complicate the temporal predictability of the system. To address this issue a predictable hardware TT scheduler is implemented in hardware. In order to overcome the possibility of the application programmer writing temporally unpredictable code, a set of software-based error-detection (and recovery) mechanisms is implemented as a “task guardian” to deal with issues of task overruns in TT systems. The performance and complexity of the initial software implementation leads to an innovative hardware task guardian solution. Overall, the implication of the studies presented in this thesis provide the system developer with an effective set of software and hardware components which are shown to provide a highly-predictable platform for the execution of time-triggered tasks sets.

Natural hazards affecting industrial installations could directly or indirectly cause an accident or series of accidents with serious consequences for the environment and for human health. Accidents initiated by a natural hazard or disaster which result in the release of hazardous materials are commonly referred to as Natech (Natural Hazard Triggering a Technological Disaster) accidents. The conditions brought about by these kinds of events are particularly problematic, the presence of the natural event increases the probability of exposition and causes consequences more serious than standard technological accidents. Despite a growing body of research and more stringent regulations for the design and operation of industrial activities, Natech accidents remain a threat. This is partly due to the absence of data and dedicated risk-assessment methodologies and tools. Even the Seveso Directives for the control of risks due to major accident hazards do not include any specific impositions regarding the management of Natech risks in the process industries. Among the few available tools there is the European Standard EN 62305, which addresses generic industrial sites, requiring to take into account the possibility of lightning and to select the appropriate protection measures. Since it is intended for generic industrial installations, this tool set the requirements for the design, the construction and the modification of structures, and is thus mainly oriented towards conventional civil building. A first purpose of this project is to study the effects and the consequences on industrial sites of lightning, which is the most common adverse natural phenomenon in Europe. Lightning is the cause of several industrial accidents initiated by natural causes. The industrial sectors most susceptible to accidents triggered by lightning is the petrochemical one, due to the presence of atmospheric tanks (especially floating roof tanks) containing flammable vapors which could be easily ignited by a lightning strike or by lightning secondary effects (as electrostatic and electromagnetic pulses or ground currents). A second purpose of this work is to implement the procedure proposed by the European Standard on a specific kind of industrial plant, i.e. on a chemical factory, in order to highlight the critical aspects of this implementation. A case-study plant handling flammable liquids was selected. The application of the European Standard allowed to estimate the incidence of lightning activity on the total value of the default release frequency suggested by guidelines for atmospheric storage tanks. Though it has become evident that the European Standard does not introduce any parameters explicitly pointing out the amount of dangerous substances which could be ignited or released. Furthermore the parameters that are proposed to describe the characteristics of the structures potentially subjected to lightning strikes are insufficient to take into account the specific features of different chemical equipment commonly present in chemical plants.

FundaÃÃo de Amparo à Pesquisa do Estado do CearÃ
Essa dissertaÃÃo fala de uma experimentaÃÃo em processo, fundamentada em colaboraÃÃo à distÃncia, envolvendo cinco artistas brasileiros que moram fora do Brasil e eu, residente em Fortaleza. O encontro com o texto âExÃlio e criatividadeâ de VilÃm Flusser à o ponto inicial dessa pesquisa. CecÃlia Almeida Salles e Gilbert Simondon, por sua vez, norteiam a escuta do percurso e os atravessamentos ao longo do processo. No trajeto, a partir dos indÃcios e atenta aos disparos, um experimento artÃstico emerge e se desenvolve no trÃnsito da imobilidade para a mobilidade. A experiÃncia à registrada em um diÃrio biogrÃfico e poÃtico compartilhado com os artistas cocriadores, enquanto anfitriÃes do experimento, recebido como hÃspede. Essa escrita (inventÃrio) à construÃda em paralelo, onde de longe, acompanho os deslocamentos. A viagem vai sendo atravessada por distintas passagens e paisagens, no entanto, questÃes como de exÃlio e estrangeiridade dialogam com o processo criativo. De instabilidades em metaestabilidades, inventam-se caminhos performativos pelos quais observo como sÃo afetados pelo gatilho da criaÃÃo. Relaciono os acontecimentos dessa pesquisa Ãs surpresas e transformaÃÃes movidas pelos processos de individuaÃÃo, bem como as percepÃÃes por estes acendidas - a relaÃÃo com o vestuÃrio, por exemplo, à uma delas.
This dissertation speaks about an experimentation in processes, founded on distance collaboration, envolving five brazilian artists living abroad, and I, in Fortaleza. The encounter with VilÃm Flusserâs text âExile and creativityâ was the inicial point of this research. CecÃlia Almeida Salles and Gilbert Simondon, in turn, have guided the hearing of the path and the crossing lines throughout the process. As I follow the route, attentive to the clues and the triggers, an artistic experiment emerges and is developed in the transit from mobility to immobility. The experience was registered in a poetic and biographic diary shared with the co-criators artists, while hosts of the experiment, received as a guest. This writing (inventory) was built in parallel, where, from a distance I followed the shiftings. The journey had been crossed over by diverse landscapes and passages, however, questions about exile and foreingnness dialogued with the creative process. From instabilities by metastabilities, performativives ways have been invented, by wich, I observe how they are affected by the creative impulse. I relate the research events to the transformations and outcomes revealed by the processes of individuation, as well as the perceptions lightened by them â the relation with clothing, for example, is one of them.

In the last decades an increasing trend of NaTech accidents (Natural Hazard Triggering Technological Disasters) is affecting industry, possibly leading to major accidents, exacerbated by the occurrence of multiple simultaneous failures, cascading events (domino effects), and the disruption of utilities, safety systems, and lifelines. In this panorama, it becomes vital to collect and analyse data on past industrial accidents caused by natural events, being almost the unique source of information on NaTech scenarios. Indeed, the main objective of the present work is to understand the dynamic of NaTech accidental events, in order to draw lessons aimed at minimizing and preventing their footprint. Firstly, a database collecting 908 accidents that affected chemical and process industries has been created. Secondly, the database has been analysed in order to find out the trend of NaTech accident compared to the one of natural events, the geographical area involved, the triggering natural events, the final scenarios that occurs, the consequences on human and the economic damages. Particular attention has been given to the presence of safety barriers and their effectiveness in case of NaTech scenarios. Depending on the availability of information, some focuses have been made on specific natural events. Lastly, Multiple Correspondence Analysis has been used to evaluate additional specific correlations between the categorical variables present in the database. Through the present technique, the relationship between each natural event and the other characteristic of the accident are clarified, such as final scenarios, macro sectors involved and consequences on human and on assets. Also in this case, the presence and the effectiveness of barriers is evaluated according to the natural events.

Safety-critical systems – such as those used in the medical, automotive and aerospace fields – have a crucial dependence on the reliable functioning of one or more embedded processors. In such systems, a co-operative software design methodology can be used to guarantee a high degree of reliability; when coupled with a time-triggered architecture, this methodology can result in robust and predictable systems with a comparatively simple software design, low operating system overhead, easier testability, greater certification support and tight jitter control. Nevertheless, the use of a co-operative design methodology is not always appropriate, since it may negatively affect system responsiveness and can add to the maintenance costs. Many alternatives have been researched and implemented over the past few decades to address such concerns, albeit by compromising on some of the benefits this architecture provides. This thesis makes five main contributions to tackle the major obstacles to single-processor time-triggered co-operative designs: • it proposes and describes the implementation of a novel multi-core processor with two capable software scheduler implementations that allow application software to be designed as for a single-core system; • it describes the internalisation of these scheduler implementations into hardware which allows application software to use all available computing capacity; • it describes a hardware technique to eliminate the variations in starting times of application software, thereby increasing the stability of applications; • it describes the implementation of a hardware technique for sharing input/output resources amongst application software with increased determinism by leveraging the time-triggered nature of the underlying system; • it describes the implementation of a predictable processor that supports purely co-operative software and is suitable for the secondary cores on a multi-core design (due to its small size). Overall, the contributions of this thesis both increase system responsiveness and lessen the impact of seemingly innocuous maintenance activities.

La química desenvolupada durant la meva tesi doctoral ha estat impulsada per la capacitat d'intermedis rics en electrons (anions fenolat i enamines quirals), generats transitòriament a partir de precursors fotoquímicament inactius (fenols i aldèhids), per arribar directament a un estat electrònicament excitat després de l'absorció de llum i, posteriorment, promovent la formació d'espècies radicalàries reactives a partir dels iodurs d'alquil adequats. En les transformacions estudiades, la formació dels radicals és a través de l'escissió reductora de l'enllaç carboni-iode del precursor de iodur d'alquil mitjançant mecanismes de transferència d'un sol electró (SET). Inicialment, he desenvolupat un nou enfocament per a la perfluoroalquilació fotoquímica directa de fenols substituïts. L'ús de llum visible simple, sense la necessitat de cap fotocatalitzador o iniciador de radicals, pot promoure la perfluoroalquilació o trifluorometilació aromàtica de fenols a temperatura ambient. En un segon projecte, he desenvolupat una nova metodologia per a la metilació o bencilació en α d'aldèhids mitjançant la fotoorganocatálisi. En aquest cas, la reacció es produeix en absència de catalitzadors fotoredox externs, i els compostos desitjats s'obtenen amb bons rendiments aïllats i elevada enantioselectivitat.
La química desarrollada durante mi tesis doctoral ha sido impulsada por la capacidad de intermedios ricos en electrones (aniones fenolato y enaminas quirales), generados transitoriamente a partir de precursores fotoquímicamente inactivos (fenoles y aldehídos), para alcanzar directamente un estado electrónicamente excitado tras la absorción de luz y, posteriormente, promover la formación de especies radicalarias reactivas a partir de los yoduros de alquilo adecuados. En las transformaciones estudiadas, la formación de los radicales es a través de la escisión reductora del enlace carbono-yodo del precursor de yoduro de alquilo mediante mecanismos de transferencia de un solo electrón (SET). Inicialmente, he desarrollado un nuevo enfoque para la perfluoroalquilación fotoquímica directa de fenoles sustituidos. El uso de luz visible simple, sin necesidad de ningún fotocatalizador o iniciador de radicales, puede promover la perfluoroalquilación o trifluorometilación aromática de fenoles a temperatura ambiente. En un segundo proyecto, he desarrollado una nueva metodología para la metilación o bencilación en α de aldehídos mediante fotoorganocatálisis. En este caso, la reacción se produce en ausencia de catalizadores fotoredox externos, y los compuestos deseados se obtienen con buenos rendimientos aislados y elevada enantioselectividad.
The chemistry developed during my doctoral thesis was driven by the ability of electron rich intermediates (phenolate anions and chiral enamines), transiently generated from photochemically inactive precursors (phenols and aldehydes), to directly reach an electronically excited state upon light absorption and subsequently promoting the formation of reactive radical species from suitable alkyl iodides. In the studied transformations, the radicals are formed through the reductive cleavage of the carbon-iodine bond within the alkyl iodide precursor via single-electron transfer (SET) mechanisms. Initially, I developed a new approach for the photochemical direct perfluoroalkylation of substituted phenols. The use of simple visible light, without the need of any photocatalyst or radical initiator, can promote an aromatic perfluoroalkylation or trifluoromethylation of phenols at ambient temperature. In a second project, I developed a new methodology for the enantioselective formal α-methylation and α-benzylation of aldehydes by means of photo-organocatalysis. The reaction occurs in the absence of external photoredox catalysts, and the desired compounds were obtained in good isolated yields with high enantioselectivity.

Novel event-triggered sensing and actuation strategies are presented for networked control systems with limited communication resources. Two architectures are considered: one with the controller co-located with the sensor and one with the control co-located with the actuator. A stochastic control problem with an optimal stopping rule is shown to capture two interesting instances of these architectures. The solution of the problem leads to a parametrization of the control alphabet as piecewise constant commands. The execution of the control commands is triggered by stopping rules for the sensor. In simple situations, it is possible to analytically derive the optimal controller. Examples illustrate how the new event-based control and sensing strategies outperform conventional time-triggered schemes.

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This Ph.D. thesis seeks to better understand how change occurs within a group of organisations. Aiming to make a contribution to institutional theory, it brings together three main schools, namely: old, new and neoinstitutionalism, in an integrative approach for understanding organisational field change. The study seeks to examine and explore a community of organisations who have come together to form an organisational field. More specifically, the object is to better understand how an organisational field is formed and developed and how change is driven, at an organisational and organisational field level, as a consequence of this field formation. Moreover, the study investigates the impact of triggers for change upon the field, and the role that institutional forces and individuals play in the process of organisational field change.The theoretical chapters, as discussed, integrate the concepts of change from three schools developing a comprehensive framework of organisational field change with which the empirical material can be analysed, in order to make the theoretical contribution. The empirical work is based on a case study, incorporating two rounds of interviews and secondary data collection, undertaken from 2007 - 2011. The case study examines the development of the Biofuel Region, a collection of organisations based, principally, in Ornskoldsvik,  Northern Sweden, that have worked together to develop a public and private biofuel transportation infrastructure. Besides being a fascinating case of regional development and having the reassuring object of creating an eco-efficient fuel the Biofuel Region, regarded as an organisational field, provided good access to respondents and useful insights into the way that fields form and change.The contributions of this thesis offer an insight into the manner with which the formation of an organisational field can begin with a drive for a legitimisation of the field's endeavours.Underscored is how the field can restructure continuously as a consequence of triggers for change, and that consequently fields are dynamic and not static and are thus changing frequently. Furthermore, it highlights that given the correct conditions individuals can play a key role in the management of an organisational field. The overarching contribution is that change occurs in a plethora of different ways within a field as a consequence of its formation,development, triggers for change, individual's contributions and institutional forces.
Denna doktorsavhandling syftar till att öka förståelsen avseende hur förändring sker inom grupper av organisationer. Med syftet att ge ett bidrag till institutionell teori sammanförs tre skolor, nämligen gammal-, ny- och neoinstitutionalism, i en integrerad strategi för att förstå förändring av organisatoriska fält. Studien syftar till att undersöka och utforska en samling av organisationer som gått samman för att bilda ett organisatoriskt fält. Mer specifikt är ändamålet att bättre förstå hur ett organisatoriskt fält bildas och utvecklas, och hur förändring drivs, både på en organisatorisk- och organisatorisk fältnivå. Dessutom undersöker studien speciella ”utlösares” effekter för förändring av fältet, och den roll som institutionella krafter och individer spelar i denna förändringsprocess. De teoretiska kapitlen integrerar begreppen förändring utifrån de tre skolorna i utvecklandet av ett övergripande ramverk, med vilket det empiriska materialet analyseras; resulterande i ett teoretiskt bidrag. Det empiriska arbetet utgår från en fallstudie, som omfattar två omgångar av intervjuer och sekundär data, insamlat mellan 2007 och 2011. Fallstudien undersöker utvecklingen av BioFuel Region, en samling av organisationer, baserade huvudsakligen i Örnsköldsvik i norra Sverige, som har arbetat tillsammans för att utveckla en offentlig och privat transportinfrastruktur för biobränsle. Förutom att vara ett fascinerande fall av regional utveckling, med den lovvärda avsikten att skapa ett eko-effektivt bränsle, innebar Biofuel Region, såsom exempel på ett organisatoriskt fält, god tillgång till respondenter och användbara insikter i hur fält formas och förändras. Bidragen i denna avhandling ger en inblick i hur bildandet av ett organisatoriskt fält kan börja med en strävan efter att legitimerera fältets aktiviteter. Betoningen ligger på hur fältet kan omstruktureras kontinuerligt som en följd av ”utlösare” för förändring, och att fält därför är dynamiska och inte statiska. Dessutom framhålls, att givet de rätta förhållandena kan individer spela en viktig roll i ledningen av ett organisatoriskt fält. Det övergripande bidraget är insikten att förändring inom ett fält sker på en uppsjö olika sätt; som en följd av dess bildande, utveckling, ”utlösare” för förändring, individuella insatser och institutionella krafter.

Aquesta tesi presenta enfocaments eficients per produir compostos d’alt valor utilitzant i valoritzant el CO2. La metodologia emprada es basa en tècniques electroquímiques, que permeten utilitzar solucions químiques ecològiques, a més de mantenir l’objectiu d’oferir una potencial estratègia a llarg termini per reduir les emissions de CO2 a l’atmosfera, al temps que s’obtenen compostos útils. A més, els líquids iònics s’introdueixen com una alternativa més ecològica als tradicionals dissolvents orgànics apròtics emprats en els experiments electroquímics. Així mateix, es presenta una síntesi sostenible d’un líquid iònic en un sol pas, utilitzant una estratègia d’intercanvi d’ions. L’enfocament electroquímic es basa en tres estratègies diferents per valoritzar el CO2; en primer lloc, la reducció directa del CO2 a la superfície dels elèctrodes en presència d’un líquid iònic basat en l’imidazol. La segona es basa en l’activació electroquímica a través de diferents fissures C-X en presència de solucions saturades de CO2, produint processos d’electrocarboxilació. El tercer es basa en un procés catalític a través d’una catàlisi homogènia, on el CO2 es redueix indirectament en la solució.
Esta tesis presenta enfoques eficientes para producir compuestos de alto valor utilizando y valorizando el CO2. La metodología empleada se basa en técnicas electroquímicas, que permiten utilizar soluciones químicas ecológicas, además de mantener el objetivo de ofrecer una potencial estrategia a largo plazo para reducir las emisiones de CO2 en la atmósfera, al tiempo que se obtienen compuestos útiles. Además, se introducen los líquidos iónicos como una alternativa más ecológica a los tradicionales disolventes orgánicos apróticos empleados en los experimentos electroquímicos. Así mismo, se presenta una síntesis sostenible de un líquido iónico en un solo paso, utilizando una estrategia de intercambio de iones. El enfoque electroquímico se basa en tres estrategias diferentes para valorizar el CO2; en primer lugar, la reducción directa del CO2 en la superficie de los electrodos en presencia de un líquido iónico basado en el imidazolio. La segunda se basa en la activación electroquímica a través de diferentes fisuras C-X en presencia de soluciones saturadas de CO2, produciendo procesos de electrocarboxilación. El tercero se basa en un proceso catalítico a través de una catálisis homogénea, donde el CO2 se reduce indirectamente en la solución.
This thesis presents efficient approaches for producing high value compounds using CO2 as a building block. The methodology employed is based on electrochemical techniques, which enable eco-friendly chemistry solutions to be used, as well as maintaining the aim of offering a potential long-term strategy for reducing CO2 emissions in the atmosphere, while obtaining useful compounds. Moreover, the ionic liquids are introduced as a greener alternative to the traditional organic aprotic solvents employed in electrochemical experiments. Also, presenting a sustainable one-pot synthesis of an ionic liquid, using an ion exchange strategy. The electrochemical approach is relaying on three different strategies to valorize CO2; firstly, the direct reduction of CO2 on the electrode surface in presence of an imidazolium-based ionic liquid. The second one is based on the electrochemical activation through different C-X cleavages in the presence of CO2 saturated solutions, producing electrocarboxylation processes. Third one is based on a catalytic process through a homogeneous catalysis, where CO2 is indirectly reduced in the solution.
Universitat Autònoma de Barcelona. Programa de Doctorat en Electroquímica. Ciència i Tecnologia

Service Oriented Virtual Organizations (SOVOs) business processes and services are subject to change to meet the internal and external requirements of the competitive, complex and rapidly changing environment they operate in. More practical and efficient ways of change management are needed to allow different partners to initiate changes to their business process and services in a faster and user-transparent manner. This thesis proposes a Change Management Framework for service oriented virtual organizations including a structural and a procedural framework. The structural framework categorizes changes in the SOVO into three layers of change; which include the value network layer, the collaborative process layer and the service providers’ layer, and identifies the impact of change on each layer. Furthermore, the structural framework identifies various triggers of changes which eventually lead to actions taken at the three layers. The change management procedural framework is derived from the ITIL V3, ECM and ECOLEAD best practices and recommendations, customized to fit the SOVO change requirements. It provides different components including the six layers for change processes, change control, change actors and related management processes. The change management procedural framework provides a sequence of steps and methods that the SOVO and its participated organizations can follow in initiating changes to their business processes or services. We design an implementation architecture and a prototype for building the change management console which enables the SOVO change management participants to initiate, assess, collaborate, monitor and authorize changes. The prototype is developed to realize and validate the change management process of change in the SOVO environment. We employ the various capabilities of the IBM Business Process Management (BPM) (including its recent Web 2.0 capabilities) to increase the collaboration between partners in the process of change. We demonstrate that the proposed solutions facilitate and enhance the process of change by effectively engaging the SOVO partners in the process of change.

Abstract The multiple-input multiple-output (MIMO) technique combined with an orthogonal frequency division multiplexing (MIMO--OFDM) has been introduced as a promising approach for the ever increasing capacity and quality of service (QoS) requirements for wireless communication systems. An efficient radio spectrum utilization expects a flexible transceiver solution, which has been the reason for the development of the software defined radio (SDR) technologies which in their turn are expected to enable the creation of cognitive radios. As a result, any radio solution could be invoked on demand on any platform. In this thesis work, we have studied detector algorithms and programmable processor architectures in order to find practical solutions for the future wireless systems. A programmable receiver can reduce the energy dissipation of the receiver by changing the detection algorithm based on the current channel realizations. To provide a realistic aspect to the implementations in different channel realizations, we present a wide state-of-the-art detector comparison. In addition, we present an extensive number arithmetic and word length study in order to evaluate realistic hardware complexity and energy dissipations of the implementations. The study includes a comprehensive design chain from the algorithm development to the actual processor design and finally programming software for the platforms. We evaluate single and multi-core processor implementations by comparing the achieved results to the Long Term Evolution (LTE) performance requirements. We implement detectors on digital signal processors (DSPs), graphics processing unit (GPU) and transport triggered architecture (TTA). The implementation results are compared in throughput, silicon area and energy efficiency. Finally, we discuss the advantages and disadvantages of the architectures and the implementation effort
Tiivistelmä Usean antennin tekniikka yhdistettynä ortogonaaliseen taajuusvaihtelumodulointiin lähetin-vastaanotimessa on esitetty eräänä lupaavana ratkaisuna jatkuvasti kasvaviin kapasiteetti- ja palvelunlaatuvaatimuksiin langattomissa tietoliikennejärjestelmissä. Tehokas radiospektrin käyttö edellyttää joustavaa lähetin-vastaanotinratkaisua, mikä on ollut syynä ohjelmistoradioteknologioiden kehitykselle. Ohjelmistoradioiden kehityksen on puolestaan odotettu mahdollistavan kognitiiviradioiden syntymisen. Tuloksena, mikä tahansa radiosovellus voitaisiin herättää tarpeen mukaan millä tahansa ohjelmoitavalla sovellusalustalla. Tässä väitöskirjatyössä tutkitaan ilmaisinalgoritmeja sekä ohjelmoitavia prosessoriarkkitehtuureja tarkoituksena löytää käytännöllisiä ratkaisuja tulevaisuuden langattomiin järjestelmiin. Ohjelmoitavalla vastaanottimella voidaan vähentää vastaanottimen energiankulutusta vaihtamalla ilmaisinalgoritmeja vallitsevan kanavatilan mukaan. Työssä esitellään laaja, viimeisintä tutkimusta edustava ilmaisinalgoritmivertailu, joka antaa realistisen näkökannan toteutuksiin erilaisissa kanavatiloissa. Lisäksi työssä esitellään numeroaritmetiikka- ja sananpituustutkimus, jonka tarkoituksena on arvioida toteutusten realistista kovokompleksisuutta sekä energiankulutusta. Tutkimus sisältää kattavan suunnitteluketjun algoritmikehityksestä todelliseen prosessorisuunnitteluun ja lopulta algoritmin ohjelmointiin tietylle sovellusalustalle. Väitöskirjatyössä arvioidaan yksi- ja moniytimisiä prosessoritoteutuksia vertaamalla saavutettuja tuloksia Long Term Evolution -standardin suorituskykyvaatimuksiin. Ilmaisimia toteutetaan digitaalisilla signaaliprosessoreilla, grafiikkaprosessorilla sekä siirtoliipaisuarkkitehtuurilla. Toteutustuloksia vertaillaan laskentatehona, pinta-alana sekä energiatehokkuutena. Lopuksi käsitellään arkkitehtuurien hyviä ja huonoja puolia sekä suunnittelun työläyttä

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Diante do inédito momento vivido pela economia brasileira e, especialmente, pela bolsa de valores nacional, principalmente após a obtenção do grau de investimento pelo Brasil, este trabalho aborda um tema que ganhou um enorme espaço na mídia atual que é a análise técnica. A partir de uma amostra de 37 ações listadas na Bolsa de Valores de São Paulo no período compreendido entre janeiro de 1999 e agosto de 2009, este trabalho examina se a análise técnica agrega valor 'as decisões de investimentos. Através da elaboração de intervalos de confiança, construídos através da técnica de Bootstrap de inferência amostral, e consistentes com a hipótese nula de eficiência de mercado na sua forma fraca, foram testados 4 sistemas técnicos de trading. Mais especificamente, obteve-se os resultados de cada sistema aplicado às series originais dos ativos. Então, comparou-se esses resultados com a média dos resultados obtidos quando os mesmos sistemas foram aplicados a 1000 séries simuladas, segundo um random walk, de cada ativo. Caso os mercados sejam eficientes em sua forma fraca, não haveria nenhuma razão para se encontrar estratégias com retornos positivos, baseando-se apenas nos valores históricos dos ativos. Ou seja, não haveria razão para os resultados das séries originais serem maiores que os das séries simuladas. Os resultados empíricos encontrados sugeriram que os sistemas testados não foram capazes de antecipar o futuro utilizando-se apenas de dados passados. Porém, alguns deles geraram retornos expressivos e só foram superados pelas séries simuladas em aproximadamente 25% da amostra, indicando que a análise técnica tem sim seu valor.
Faced with unprecedented time lived by Brazilian`s economy and, especially, the national stock exchange, mainly after obtaining the investment grade for Brazil, this paper addresses a theme that has deserved a huge space in the mainstream media that is technical analysis. From a sample of 37 stocks listed on the Stock Exchange of Sao Paulo in the period between January 1999 and August 2009, this paper examines if the technical analysis may or may not add value to investment decisions. Through the development of confidence intervals, constructed using the technique of Bootstrap sample inference, and consistent with the null hypothesis of market efficiency in its weak form, we tested 4 technical systems of trading. More specifically, we obtained the results of each system applied to the original series of the assets. Then we compared these results with the average of the results obtained when the same systems were applied to 1000 simulated series, according to a random walk, of each asset. If markets are efficient in its weak form, there would be no reason to find strategies with positive returns based only on historical values of assets. That is, there would be no reason for the results of the original series to be larger than those of the simulated series. The empirical results found here suggested that the systems tested were unable to anticipate the future using only past data. However, some of them have generated significant returns and were surpassed only by the series simulated in approximately 25% of the sample, indicating that technical analysis does have value.

Neste trabalho pretendemos mostrar alguns aspectos importantes no desenho de instrumentação para sistemas de selecção de eventos (trigger), que se revelaram importantes no desenho do sistema de trigger de CP–LEAR. Para isso, fazemos um zoom progressivo sobre a experiência. Começamos por mostrar o que são sistemas de trigger, quais as suas propriedades e diversidade, e que tipos de sistemas são usados e em que circunstâncias. É também feito um apanhado do state of the art dos diversos componentes e soluções utilizadas para a resolução dos problemas típicos destes sistemas. A seguir, apresentamos CP–LEAR, descrevendo a física em que se apoia o seu método. Aqui introduzimos o conceito de simetrias, e em que circunstâncias podemos falar de violação de simetria. Seguidamente, introduzimos o sistema de kaões neutros, apresentamos o fenómeno de violação CP, e descrevemos o método de CP–LEAR utilizado para o seu estudo. Depois de apresentar o detector utilizado na experiência, começamos a debruçar-nos sobre o sistema de trigger de CP–LEAR. Descrevemos a sua arquitectura, o que a faz ser tão peculiar, e os seus algoritmos. Dos vários processadores apresentados, debruçamo-nos mais sobre a parte mais rápida, o pre–trigger e o processador HWP1. Fazemos também uma breve discussão da arquitectura, apontando alguns dos seus aspectos positivos e negativos. Finalmente, partindo do sistema de trigger, fazemos um zoom sobre um dos níveis de decisão que constituem o pre–trigger, um processador rápido de cortes em momento transverso, o PTCUT. Aqui tentamos mostrar os argumentos que levaram à definição do algorítmo, a sua implementação em hardware e, finalmente, fazemos uma discussão dos resultados observados. Terminamos com a apresentação do software usado.

Les infrastructures de transport est essentielle au maintien et à l'expansion des activités sociales et économiques dans les régions circumpolaires. À mesure que le climat se réchauffe, la dégradation du pergélisol sous les remblais a entraîné de graves dommages structuraux à la route, entraînant une augmentation importante des coûts d'entretien et une réduction de la durée de vie des infrastructures. Pendant ce temps, l'advection de chaleur déclenchée par les écoulements d’eau souterrains peut altérer le bilan énergétique du remblai et du pergélisol sous-jacent et modifier le régime thermique des remblais routiers. Cependant, peu de recherches ont été effectuées pour comprendre la synergie entre les processus thermiques de surface et souterrains des remblais routiers des régions froides. L'objectif de cette recherche était de comprendre les interactions thermiques entre l'atmosphère, le remblai routier, les écoulements d’eau et le pergélisol dans le contexte du changement climatique. Cette base, de connaissances est nécessaire pour la conception technique, l'entretien des routes et l'évaluation de la vulnérabilité des infrastructures. Les travaux de recherche ont permis de développer de nouvelles méthodes d'analyse thermique pour caractériser et identifier le rôle de l'advection thermique sur le changement de température d'un remblai routier expérimental au Yukon (Canada) en termes d’intensité, de vitesse et de profondeur de l'impact thermique. Les résultats montrent que l'augmentation de la température due aux flux de chaleur advectifs déclenchés par l’écoulement d'eau peut être jusqu'à deux ordres de grandeur plus rapide qu'en raison du seul réchauffement atmosphérique. La recherche a ensuite présenté un bilan énergétique de surface pour quantifier la quantité d'énergie entrant dans le centre et la pente du remblai avec des épaisseurs et des propriétés de neige variables. Le tout a été appuyé par des observations géothermique de plusieurs années et une grande quantité de données météorologiques. Les résultats illustrent que le bilan énergétique de surface est principalement contrôlé par le rayonnement net et moins par le flux de chaleur sensible. Le flux de chaleur transmis à la pente du remblai diminue de façon exponentielle avec l'augmentation de l'épaisseur de la neige et diminue de façon linéaire avec l’installation du couvert de neige et la longueur de la période d’enneigement. De plus, un modèle de bilan énergétique de surface et un modèle cryohydrologique entièrement couplé ont été développés pour étudier l'impact thermique de l'advection de chaleur associée à l'écoulement de l'eau souterraine sur le dégel du pergélisol et le développement de taliks (c.-à-d. zone perpétuellement non gelée dans les zones de pergélisol). Le modèle couplé a réussi à reproduire la tendance à la hausse du plafond du pergélisol (erreur absolue moyenne <0,2 m) au cours de la période 1997-2018. Les résultats montrent que l'advection de chaleur a fourni une source d'énergie supplémentaire pour accélérer le dégel du pergélisol et a doublé le taux d’augmentation de l’épaisseur de la couche active 0,1 m·a-1 à 0,19 m·a-1, par rapport au scénario où aucun écoulement d'eau ne se produit. Le talik s'est initialement formé et développé en fonction du temps sous l’effet combiné des écoulement d’eau, de l'isolation de la neige, de la construction de la route et du réchauffement climatique. Le débit d'eau souterraine a relié des corps isolés de talik et a amené le remblai de la route dans un état thermique irréversible, en raison de la rétroaction de l'eau liquide (effet de chaleur latente) piégée dans le talik. Ces résultats montrent l'importance de l'advection de chaleur induite par l'écoulement d'eau sur le régime thermique de la sous-couche (c.-à-d. la couche de matériau de remblai) et du sous-sol (c.-à-d. le matériau natif sous un remblai) du remblai lorsque le remblai routier intercepte le drainage local. De plus, les résultats obtenus soulignent la nécessité de coupler les processus thermiques de surface et souterrains dans le but d'évaluer la stabilité thermique des routes subarctiques.
Transportation infrastructure is crucial to maintaining and expanding the social and economic activities in circumpolar regions. As the climate warms, degradation of the permafrost causes severe structural damages to the road embankment, leading to large increases in maintenance costs and reductions in its lifespan. Meanwhile, heat advection triggered by mobile water flow can alter energy balance of the embankment and underlying permafrost and modify the thermal regime of road embankments. However, little research has been done to understand the synergy between surface and subsurface thermal processes of cold region road embankments. The overall goal of this research was to elucidate thermal interactions between the atmosphere, the road embankment, mobile water flow, and permafrost within the context of climate change. This knowledge is needed for engineered design, road maintenance, and infrastructure vulnerability assessment. The research first used new thermal analysis to characterize and identify the role of heat advection on temperature change of an experimental road embankment, Yukon, Canada in terms of magnitude, rate and thermal impact depth. It shows that soil temperature increase due to advective heat fluxes triggered by mobile water flow can be up to two orders of magnitude faster than due to atmospheric warming only. The research then presented a novel surface energy balance to quantify the amount of ground heat flux entering the embankment center and slope with varying snow depth and properties, supported by multi-year thermal and meteorological observations. My results illustrate that the surface energy budget is mainly controlled by net radiation, and less by the sensible heat flux. The ground heat flux released at embankment slope exponentially decreased with the increase of snow depth, and was linearly reduced with earlier snow cover and longer snow-covered period. A fully integrated surface energy balance and cryohydrogeological model was implemented to investigate the thermal impact of heat advection associated with subsurface water flow on permafrost thaw and talik (i.e., perennially unfrozen zone in permafrost areas) development. The integrated model successfully reproduced the observed increasing trend of the active layer depth (mean absolute error < 0.2 m) over the 1997-2018 period. The results show that heat advection provided an additional energy source to expedite permafrost thaw, doubling the increasing rate of permafrost table depth from 0.1 m·a-1 to 0.19 m·a-1, compared with the scenario where no water flow occurs. Talik formation and development occurred over time under the combined effect of subsurface water flow, snow insulation, road construction and climate warming. Subsurface water flow connected isolated talik bodies and triggered an irreversible thermal state for the road embankment, due to a local feedback mechanism (latent heat effect) of trapped, unfrozen water in talik. These findings elucidate the importance of heat advection induced by mobile water flow on the thermal regime of embankment subbase (i.e., a layer of fill material) and subgrade (i.e., the native material under an embankment) when the road embankment intercepts the local drainage. Furthermore, the obtained results emphasize the need to couple surface and subsurface thermal processes to evaluate the thermal stability of sub-Arctic roads.

Dissertação de mestrado integrado em Engenharia de Polímeros
A crescente exigência dos mercados obriga as empresas a investirem cada vez mais na inovação, quer dos produtos que desenvolvem, quer dos processos e metodologias utilizadas para os desenvolver. A presente tese de mestrado foi desenvolvida em ambiente industrial com a colaboração da empresa EDINyourideas e é uma continuidade do trabalho realizado durante o primeiro semestre na unidade curricular “Projecto individual”, que se baseou na identificação de uma oportunidade de produto e desenvolvimento de metodologias de processo. O produto a desenvolver consiste num sistema alternativo, em plástico, de abertura de portas accionado pelo pé, destinado à aplicação em locais públicos, nomeadamente casas de banho (compartimento individual). Ao longos dos anos assistiu-se a um grande desenvolvimento no sentido de reduzir o contacto das mãos nesses locais, aumentando assim o nível de higiene, particularmente através de caixotes do lixo e autoclismos com sensores ou de pedal. No entanto esta redução do contacto é inútil quando os métodos de abertura de portas continuam rudimentares e recorrendo à utilização da mão. O tema desta dissertação de mestrado baseia-se então na concepção e desenvolvimento desse produto. Contudo, é preciso ter em consideração que o desenvolvimento de peças, neste caso em plástico, é uma tarefa muito complexa que requer, além de uma vasta equipa, a intervenção simultânea de diversas áreas, bem como a consideração de aspectos essenciais ao projecto, de forma a obter um produto final esteticamente atraente, com boa funcionalidade, resistência mecânica e baixo custo de produção. Este trabalho é composto então por cinco fases principais: desenvolvimento preliminar do produto, projecto mecânico, optimização tecnológica, definição das tecnologias de transformação e avaliação económica ao projecto. Em conclusão, pretende-se a obtenção de um produto que satisfaça da melhor forma possível as necessidades dos clientes, reduzindo assim o contacto das mãos com determinados objectos em locais públicos e por sua vez possíveis contaminações. Por outro lado, espera-se a criação de uma nova metodologia de desenvolvimento de novos produtos mais dinâmica e detalhada que possa servir de suporte na concepção de outros produtos e que vise, principalmente o aumento da qualidade, a diminuição do ciclo de desenvolvimento e a redução de custos.
The increasing demands of the market, not only requires that companies invest more in the innovation of the products they develop, but also in the processes and methodologies involved in their creation. This dissertation was developed in an industrial environment in conjunction with the company “EDINyourideas” and deepens the work performed during the first semester, in the course “Projecto individual”, that consisted in the identification of a new product opportunity and development of methodologies of process. The product that was developed, consists of a new system made of plastic, capable of opening doors using the foot, that is intended to be used in public places, more specifically, in public bathrooms. Over the years several solutions like the use of trash bins and toilet flushes that are operated by foot, were used to avoid the contact of human hands with that kind of surfaces, in an attempt to increase the overall hygiene in that kind of places. Unfortunately, the current use of rudimentary door opening mechanisms, that require hand contact, defeats the purpose of using more advanced solutions such as trash bins operated by foot. The theme of this dissertation is then the conception and development of a product that permits opening doors using the foot only. It is necessary to be aware that the development of parts, in particular, plastic parts, is a very complex task that not only requires the consideration of the essential aspects of the project, but also requires taking into account several other aspects, namely, the necessity of using large teams and the multidisciplinary nature of this kind of projects, in order to obtain a final product that is functional, esthetically good, resistant and cheap to produce. This work is constituted by five main phases: prelaminar product development, mechanical project, technological optimization, definition of the technologies of transformation and the economical evaluation of the project. In conclusion, it is desired to obtain a product that satisfies the client needs the best way possible, reducing the contact of the client hands with certain objects in public places, avoiding that way possible contaminations derived of such contact. On the other side, it is expected a creation of a new product development methodology, more dynamic and detailed, which may serve as a support for development of other products, with the objectives of increasing the product quality, focused on client necessities, development cycle reduction and cost reduction.

Tese de doutoramento em Altos Estudos Contemporâneos, na especialidade de Ciência Política (História Política e Estudos Internacionais), apresentada à Faculdade de Economia da Universidade de Coimbra
A presente investigação analisa e compara material publicado por dois jornais, – Folha de São Paulo, do Brasil, e Público, de Portugal -, sobre referendos realizados nos dois países, respectivamente, em 2005 e 2007. O objetivo é verificar se nesse material há falas com argumentos que possam ser considerados úteis para contribuir com um processo deliberativo, na perspectiva da democracia defendida por Jürgen Habermas. Ancorado numa sugestão de Simone Chambers, o material jornalístico é classificado como retórica plebiscitária ou retórica deliberativa. A retórica plebiscitária se caracteriza pela presença de mais elementos que não contribuem para a realização de uma deliberação pública, enquanto a deliberativa contém significativa presença de subsídios considerados importantes para o desenvolvimento desse processo. O reforço de alguns elementos no material jornalístico, – e a investigação avalia e quantifica quais elementos a mídia privilegia -, pode fazer com que se aproxime ou se distancie daquilo que é qualificado como importante para um debate público numa perspectiva habermasiana. A decisão de acionar mais um ou outro elemento está entre as opções que a mídia faz. Ao optar, ela sai de uma zona de fronteira, com várias possibilidades em aberto, e realiza um processo de demarcação. E, ao demarcar, ela estabelece limites, seja para um ou para outro processo. Considerando que a mídia tem potenciais ambivalentes, a investigação assume este pressuposto: não é possível definir a priori o papel que a mídia desempenha em eventos específicos de deliberação pública, como no caso dos referendos, isto porque em seu material comparecem todos os elementos da retórica, tanto os tendentes a favorecer como aqueles que prejudicam um processo deliberativo. Mas dada sua lógica de produção e divulgação, ela revela alguns dos seus limites que a impedem de complexificar os temas da agenda pública. E a hipótese que se assume nesta tese é que as escolhas da mídia privilegiam mais os elementos da retórica que se coadunam com a lógica da evidência, que é refratária a um processo argumentativo. Por acionar em maior número os elementos que são limitadores de um processo argumentativo, é temerário apontar a mídia como fórum central para a deliberação pública. E, se o seu poder de abrangência pode ser tomado como potencialmente útil para a realização de processos deliberativos nas democracias contemporâneas, a simples disponibilidade desse dispositivo não permite chegar à conclusão açodada de que sua prática contribua efetivamente para o desenvolvimento do debate público. Pelo seu potencial, e por permitir que em seu interior também circule material identificado como uma retórica deliberativa, até pode-se ver na mídia um ator capacitado a realizar um papel complementar, mas não central, no processo mais amplo da deliberação pública. E, nessa linha de análise, não se pode descartar por completo a possibilidade de o material produzido pela mídia ser desencadeador de um processo deliberativo na sociedade ao ser apropriado ou reinterpretado de diferentes maneiras pelos diversos atores da esfera pública.