L'intégration 3DVLSI, également connue sous le nom d'intégration monolithique ou séquentielle, est présentée et évaluée dans cette thèse comme une alternative à la réduction du nœud technologique des circuits logiques CMOS. L’avantage principal de cette technologie par rapport à l'intégration parallèle 3D, déjà existante, est l'alignement précis entre les niveaux, ce qui permet des contacts 3D réduits et plus proches. Un autre avantage, extrêmement favorable à l’approche 3DVLSI, est l’amélioration du placement et du routage par rapport aux circuits planaires, notamment parce qu’elle permet des interconnexions plus courtes et qu’elle offre a un degré de liberté supplémentaire dans la direction Z pour la conception. Par exemple, les fils les plus longs dans les circuits planaires peuvent ainsi être réduits grâce aux contacts 3DCO, en diminuant les éléments parasites d'interconnexion. Il est ainsi possible d’augmenter la vitesse du circuit et de réduire la puissance électrique. Dans ce contexte, la thèse a été divisée en deux parties. La première partie traite de l’évaluation de la Consommation, des Performances et de la Surface (CPS) et donne des recommandations pour la conception des circuits 3D. La deuxième partie traite la variabilité des circuits 3D en utilisant un modèle statistique unifié, et en proposant une approche pour la variabilité des circuits multi-niveaux. / 3DVLSI integration, also known as monolithic or sequential integration is presented and evaluated in this thesis as a potential contender to continue the scaling for CMOS logic circuits. The main advantage of this technology compared to the already existing 3D parallel integration is its high alignment among tiers, enabling small size and pitch with the inter-tier contacts (3DCO). Another great 3DVLSI feature is its improved capability to place and route circuits, compared to the planar approach: the interconnections can be shorter as the design has an additional degree of freedom in the Z direction. For instance, long wires in planar circuits can cut thanks to 3DCO contacts, lowering the interconnection parasitic elements and speeding up the circuit as well as reducing the power. In this framework, the thesis has been divided into two parts: the first part is dedicated to the evaluation of Performance, Power and Area (PPA) of 3D circuits and gives design guidelines. The second part treats the variability in 3D circuits by using a 3D unified statistical model and propose an approach for the multi-tier variability.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-05-09T17:24:59Z No. of bitstreams: 1 LENARDO CHAVES E SILVA - TESE PPGCC 2015..pdf: 9863003 bytes, checksum: b4ff7a7517f3ec159596b4b3c8730219 (MD5) / Made available in DSpace on 2018-05-09T17:24:59Z (GMT). No. of bitstreams: 1 LENARDO CHAVES E SILVA - TESE PPGCC 2015..pdf: 9863003 bytes, checksum: b4ff7a7517f3ec159596b4b3c8730219 (MD5) Previous issue date: 2015-11-12 / Capes / Sistemas Médicos Físico-Cibernéticos (SMFC) são sistemas críticos cientes de contexto que têm a segurança do paciente como principal requisito, demandando processos rigorosos de validação para garantir a conformidade com os requisitos do usuário e a corretude orientada à especificação. Neste trabalho é proposta uma arquitetura baseada em modelos para validação de SMFC, focando em promover a reúso e a produtividade. Tal abordagem permite que desenvolvedores de sistemas construam modelos formais de SMFC baseados em uma biblioteca de modelos de pacientes e dispositivos médicos, bem como simular o SMFC para identificar comportamentos indesejados em tempo de projeto. A abordagem proposta foi aplicada a três diferentes cenários clínicos para avaliar seu potencial de reúso para diferentes contextos. A abordagem foi também validada por meio de uma avaliação empírica com desenvolvedores para avaliar o reúso e a produtividade. Finalmente, os modelos foram formalmente verificados considerando os requisitos funcionais e de segurança, além da cobertura dos modelos. / Medical Cyber-Physical Systems (MCPS) are context-aware, life-critical systems with patient safety as the main concern, demanding rigorous processes for validation to guarantee user requirement compliance and specification-oriented correctness. In this article, we propose a model-based approach for early validation of MCPS, focusing on promoting reusability and productivity. It enables system developers to build MCPS formal models based on a library of patient and medical device models, and simulate the MCPS to identify undesirable behaviors at design time. Our approach has been applied to three different clinical scenarios to evaluate its reusability potential for different context. We have also validated our approach through an empirical evaluation with developers to assess productivity and reusability. Finally, our models have been formally verified considering functional and safety requirements and model coverage.

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L’objectif de cette recherche doctorale est de décrire et comprendre les effets de la programmation informatique sur l’apprentissage et la mobilisation de compétences d’élèves du primaire. Notre intérêt pour ce phénomène se justifie sous deux considérations : d’abord, la programmation est une activité qui a connu une démocratisation au cours des dernières années, notamment dans le milieu scolaire. Puis, en ce qui concerne la résolution collaborative de problèmes (RCP), il s’agit de compétences appartenant à ce que certains appellent les compétences du 21e siècle (voir notamment Chalkiadaki, 2018; van Laar et al., 2017), et que d’autres appellent les compétences du futur (Conseil des compétences futures, 2020; Gouvernement du Canada, 2020). Les recherches empiriques menées en contextes authentiques de classe sont très peu nombreuses dans la littérature (Lye et Koh, 2014), ce qui atteste pour nous la nécessité de porter un regard contemporain et imprégné des nouvelles tendances technopédagogiques sur ce phénomène d’envergure internationale. Les principaux référents conceptuels sont associés au champ de l’apprentissage collaboratif à l’aide de l’ordinateur (en anglais le Computer-supported collaborative learning, CSCL), un champ dont nous citons plusieurs travaux réalisés dans les années 1990 (Koschmann et al., 1996; Scardamalia et Bereiter, 1994). Il nous a permis d’aborder les aspects techniques (programmation, ordinateur), sociaux (interactions, médiatisation) et pédagogiques (apprentissage, développement de compétences) du phénomène que nous souhaitions étudier. À l’aide d’un devis qualitatif et interprétatif de type étude de cas multiples, nous avons mis en place un scénario pédagogique dans trois écoles primaires au Québec. Amenant les élèves à découvrir graduellement les concepts fondamentaux de la programmation informatique, le scénario Deviens un maître NAO mise sur la programmation visuelle et tangible pour mobiliser, voire développer, un ensemble d’habiletés et de compétences, tant transversales que disciplinaires. Une série de 20 niveaux sont proposés aux élèves, qui doivent réaliser des programmes ayant pour but d’animer un robot humanoïde nommé NAO. Le premier cas a été observé dans une école alternative de Montréal. Les élèves (n=29) ont été séparés en équipes multiniveau, ce qui a amené la collaboration d’élèves d’âges et de niveaux scolaires différents. Les cas 2 à 5 ont été étudiés dans une école de Montréal et présentent des élèves de quatrième, cinquième et sixième année (n=70). Enfin, le dernier cas se situait dans une classe de cinquième année de la grande région de Québec (n=10). Plusieurs de ces élèves ont des difficultés d’apprentissage ou sont en situation de handicap. Nous avons observé les pratiques effectives de programmation ainsi que la mobilisation des compétences de RCP à l’aide d’un appareillage méthodologique considérable : (a) une caméra filmant l’activité des élèves dans leur environnement immédiat, (b) la caméra intégrée de l’ordinateur qui filmait le visage des élèves et leurs interactions verbales, et (c) l’enregistrement de l’écran d’ordinateur que les élèves utilisaient pour faire la programmation visuelle et tangible du robot NAO. Nous avons ensuite utilisé ce corpus de données vidéos pour déterminer une typologie des pratiques effectives de programmation d’élèves du primaire, pour créer une grille d’observation de la RCP à partir d’observations empiriques et authentiques et pour comprendre le processus de RCP dans le cadre d’une activité de programmation au primaire. Parmi les principaux résultats, nous proposons une typologie des pratiques de programmation visuelle fortement basée sur nos observations empiriques, ce qui l’ancre fortement dans la réalité du terrain de recherche. Puis, nous avons également été en mesure de concevoir une grille d’observation de la RCP en nous appuyant sur les travaux scientifiques antérieurs et, surtout, sur nos observations empiriques. Cette grille, présentant 3 dimensions et 15 indicateurs, permet d’observer les processus et habiletés mis en œuvre par les élèves de façon collaborative. Enfin, l’utilisation de cette grille a mené à l’analyse systématique et compréhensive de la façon dont les élèves parvenaient à compléter les activités de programmation de façon collaborative. Nous soulignons d’une part la prépondérance de certaines habiletés (échanges à propos du problème, attribution explicite ou implicite des rôles, vérification des solutions, etc.), et d’autre part la faible mobilisation d’habiletés comme l’adaptation des interventions, l’identification des forces et des faiblesses et la vérification des actions. / The objective of this doctoral research is to describe and understand the effects of computer programming on the learning and mobilization of skills of elementary school students. Our interest in this phenomenon is justified by two considerations: first, programming is an activity that has been democratized in recent years, especially in the school environment. Second, with respect to collaborative problem solving (CPS), these are skills that belong to what some call 21st century skills (see, for example, Chalkiadaki, 2018; van Laar et al., 2017), and others call future skills (Future Skills Council, 2020; Government of Canada, 2020). Empirical research conducted in authentic classroom contexts is very scarce in the literature (Lye and Koh, 2014), which attests to the need for us to take a contemporary look at this international phenomenon, infused with new techno-pedagogical trends. The main conceptual referents are associated with the field of Computer-supported collaborative learning (CSCL), a field from which we cite several studies conducted in the 1990s (Koschmann et al., 1996; Scardamalia and Bereiter, 1994). It allowed us to address the technical (programming, computer), social (interactions, mediatization) and pedagogical (learning, skill development) aspects of the phenomenon we wanted to study. Using a qualitative and interpretative multiple case study design, we implemented a pedagogical scenario in three elementary schools in Quebec. By gradually introducing students to the fundamental concepts of computer programming, the Become a NAO Master scenario relies on visual and tangible programming to mobilize and even develop a set of skills and competencies, both transversal and disciplinary. A series of 20 levels are offered to students, who must create programs to animate a humanoid robot named NAO. The first case was observed in an alternative school in Montreal. The students (n=29) were separated into multi-level teams, which led to the collaboration of students of different ages and grade levels. Cases 2-5 were studied in a Montreal school and featured students in grades 4, 5, and 6 (n=70). Finally, the last case was in a fifth grade class in the greater Quebec City area (n=10). Many of these students have learning difficulties or disabilities. We observed the effective programming practices as well as the mobilization of CPR skills using a considerable methodological apparatus. Indeed, for each team in each class, we had: (a) a camera filming students' activity in their immediate environment, (b) the computer's built-in camera that filmed students' faces and verbal interactions, and (c) the recording of the computer screen that students used to do the visual and tangible programming of the NAO robot. We then used this video data set to determine a typology of elementary students' effective programming practices, to create a CPS observation grid based on empirical and authentic observations, and to understand, using the created grid, the process of CPS in an elementary programming activity. Among the main results, we propose a typology of visual programming practices strongly based on our empirical observations, which anchors it strongly in the reality of the research field. Then, we were also able to design a CPS observation grid based on previous scientific works and, above all, on our empirical observations. This grid, presenting 3 dimensions and 15 indicators, allows us to observe the processes and skills implemented by the students in a collaborative manner. Finally, the use of this grid led to a systematic and comprehensive analysis of the way in which students managed to complete programming activities in a collaborative manner. On the one hand, we note the preponderance of certain skills (exchanges about the problem, explicit or implicit assignment of roles, verification of solutions, etc.), and on the other hand, the weak mobilization of skills such as adapting interventions, identifying strengths and weaknesses, and verifying actions.

Cette recherche s’intéresse à comprendre le vécu expérientiel d’intervenant.es de la protection de la jeunesse ayant travaillé auprès d’un groupe sectaire. Le premier objectif est de décrire leur vécu ainsi que les effets perçus de l’intervention aux plans personnel et professionnel. Ensuite, les facteurs ayant influencé leur vécu sont explorés. En dernier, des pistes afin d’améliorer le vécu des intervenant.es sont dégagées en prévision d’intervention dans des contextes similaires. Les contenus d’entrevues individuelles réalisées auprès de douze intervenant.es des équipes de l’évaluation et de l’application des mesures ayant travaillé dans la situation ciblée ont été soumis à une analyse thématique. Les résultats soulèvent plusieurs facteurs influençant la façon dont l’expérience est vécue par les intervenant.es, particulièrement selon l’étape du processus de la protection de la jeunesse. Les deux équipes décrivent une expérience différente. D’un côté, l’équipe de l’évaluation rapporte un vécu lourd et intense. D’un autre côté, les intervenant.es de l’application des mesures décrivent une expérience décevante et frustrante. De plus, selon les répondant.es, l’intervention a eu des effets dans les sphères personnelles (ex. affective) et professionnelles (ex.satisfaction au travail). Les participant.es de l’étude proposent des pistes d’amélioration en lien avec l’organisation et les conditions de travail ainsi qu’avec le soutien psychologique. Le mandat d’intervention différent des deux équipes ainsi que la présence de facteurs de risque associés au développement de difficultés émotionnelles semblent expliquer la distinction entre les vécus. En somme, l’intervention auprès d’un groupe s’apparentant à un mouvement sectaire constitue un contexte de travail exceptionnel et exigeant. Des mesures précoces pour assurer le bien-être ainsi que le soutien psychologique et clinique sont importantes afin d’améliorer le vécu expérientiel. / This research project sought to understand the lived experiences of child protective services caseworkers who intervened with a sect. The primary objective was to describe the CPS caseworkers’ experiences and their perception of the effects of the intervention on their personal and professional lives. Second, the factors that influenced their lived experiences were explored. Last, ways to improve CPS caseworkers’ lived experiences were identified, with a view to future interventions in similar settings. Thematic analysis was performed on the content of the individual interviews conducted with 12 CPS members of the assessment and service provision teams who had worked in the setting in question. The results point to a number of factors that influenced their lived experiences, in particular in relation to specific stages of the child protection process. The two teams described quite different experiences. On the one hand, the assessment team reported an intense, stressful experience. In contrast, the service provision team spoke of a disappointing, frustrating experience. Furthermore, the respondents said that the intervention impacted the personal (e.g., emotional) and professional (e.g., job satisfaction) spheres of their lives. Study participants suggested ways to improve their lived experiences in terms of organization and working conditions, as well as through psychological support. The differences between the lived experiences of the two teams would appear to stem from their different intervention mandates and the presence of risk factors associated with the development of emotional issues. To sum up, CPS intervention with members of a sect-like movement is an exceptional, very demanding work environment. It is essential to take early measures to ensure CPS caseworker well-being and provide psychological support and clinical supervision in order to improve their lived experiences.

Объектом исследования являются образцы из сплава Э125 (Zr – 2,5 масс. % Nb), вырезанных из канала системы управления и защиты (СУЗ), после эксплуатации в реакторе энергоблока Смоленской АЭС в течение 36 лет. Методами металлографического анализа, испытаний на трещиностойкость и растяжением кольцевых образцов, сканирующей электронной микроскопии с дифракцией отражённых электронов и определения содержания водорода, были проведены исследования образцов после эксплуатации в энергетическом реакторе. Определены кратковременные механические свойства и характеристики трещиностойкости образцов при комнатной и температуре 100 °С. Изучена микроструктура, фазовый состав и состояние поверхности образцов канала СУЗ. Определено содержание водорода в образцах из зоны термического влияния электроннолучевого сварного соединения. / The object of the study is samples of alloy E125 (Zr – 2,5 mass. % Nb), cut from the channel of the control and protection system, after operation in the reactor of the power unit of the Smolensk NPP for 36 years. Methods of metallographic analysis, tests for fracture toughness and tensile tests of ring samples, scanning electron microscopy with reflected electron diffraction and determination of hydrogen content were used to study the samples after operation in a power reactor. The short-term mechanical properties and characteristics of the crack resistance of the samples at room temperature and 100 ° C were determined. The microstructure, phase composition and state of the surface of the CPS channel samples have been studied. The hydrogen content in the samples from the heat-affected zone of the electron-beam welded joint was determined.

Organic coatings are extensively used as protective coatings in several industries including the automotive and aircraft industries. The last few years have witnessed an increased interest in improving not only the mechanical properties but also the corrosion protection properties of organic coatings. Among the currently investigated methods of improving the performance of organic coatings is the incorporation of additives in the organic paint matrix. Vapor grown carbon nanofibers (VGCNFs) are a class of carbon fibers that are produced by catalytic dehydrogenation of a hydrocarbon at high temperatures. Depending on the method of synthesis and the post-treatment processes, the diameter of the VGCNFs is normally in the 10-300 nm range. The small size, light weight, high aspect ratio, and unique physical, thermal, mechanical, and electrical properties of VGCNF make it an ideal reinforcing filler in polymer matrix nanocomposites to enhance the mechanical properties of the pure polymeric material in high performance applications in several industries such as the automotive, aircraft, battery, sensors, catalysis, electronics, and sports industries. The main objective of the current investigation was to study the corrosion protection offered by the incorporation of VGCNFs into a commercial alkyd paint matrix applied to the surface of mild steel coupons. The corrosion protection was investigated by immersing samples in air saturated 3% NaCl solution (artificial seawater). The samples were studied by electrochemical impedance spectroscopy (EIS) along with other measurements, including electrochemical (open circuit potential, cyclic voltammetry), chemical (salt spray test), electrical conductivity, and surface analysis (SEM, AFM, optical profilometry, and nanoindentation). The study involved the investigation of the effect of the weight percent (wt %) of the VGCNF as well as the coating film thickness on the corrosion protection performance of the coated steel samples when exposed to the corrosive electrolyte. By way of contrast, the EIS behavior of steel coupons coated with a paint coating incorporating different weight percents of powdered silicon carbide (SiC) particles was also studied. The EIS spectra were used to calculated and graph several corrosion parameters for the investigated systems. At the end, the studied coatings were ranked in order of their anticorrosive properties.

The manufacturing industry is competitive and is constantly striving to improve OEE. In the transition to smart production, digital technologies such as IIoT are highlighted as important. IIoT platforms enable real-time monitoring. In this sense, digital technologies such as IIoT are expected to improve OEE by enabling the analysis of real-time data and production availability.  A qualitative study with an abductive approach has been conducted. The empirical material has been collected through a case study of a heavy-duty vehicle industry and the theoretical framework is based on a literature study. Lastly, a thematic analysis has been used for the derivation of appropriate themes for analysis. The study concluded that challenges and enablers related to the implementation of IIoT to improve OEE can be divided into technical and cultural factors. Technical challenges and enablers mainly consider the achievement of interoperability, compatibility, and cyber security, while cultural factors revolve around digital acceptance, competence, encouragement of digital curiosity, and creating knowledge and understanding towards OEE. Lastly, conclusions can be drawn that implementation of IIoT has a positive effect on OEE since it ensures consistent and accurate data, which lies a solid foundation for production decisions. Also, digitalization of production enhances lean practices which are considered a key element for improving OEE.

Lite-Agro studies applications of TinyML in pear (Pyrus communis) tree disease identification and explores hardware implementations with an ESP32 microcontroller. The study works with the DiaMOS Pear Dataset to learn through image analysis whether the leaf is healthy or not, and classifies it according to curl, healthy, spot or slug categories. The system is designed as a low cost and light-duty computing detection edge solution that compares models such as InceptionV3, XceptionV3, EfficientNetB0, and MobileNetV2. This work also researches integration with federated learning frameworks and provides an introduction to federated averaging algorithms.

Networked control over wireless networks is of growing importance in many application domains such as industrial control, building automation and transportation systems. Wide deployment however, requires systematic design tools to enable efficient resource usage while guaranteeing close-loop control performance. The control system may be greatly affected by the inherent imperfections and limitations of the wireless medium and malfunction of system components. In this thesis, we make five important contributions that address these issues.  In the first contribution, we consider event- and self-triggered control and investigate how to efficiently tune and execute these paradigms for appropriate control performance. Communication strategies for aperiodic control are devised, where we jointly address the selection of medium-access control and scheduling policies. Experimental results show that the best trade-off is obtained by a hybrid scheme, combining event- and self-triggered control together with contention-based and contention-free medium access control. The second contribution proposes an event-based method to select between fast and slow periodic sampling rates. The approach is based on linear quadratic control and the event condition is a quadratic function of the system state. Numerical and experimental results show that this hybrid controller is able to reduce the average sampling rate in comparison to a traditional periodic controller, while achieving the same closed-loop control performance. In the third contribution, we develop compensation methods for out-of-order communications and time-varying delays using a game-theoretic minimax control framework. We devise a linear temporal coding strategy where the sensor combines the current and previous measurements into a single packet to be transmitted. An experimental evaluation is performed in a multi-hop networked control scenario with a routing layer vulnerability exploited by a malicious application. The experimental and numerical results show the advantages of the proposed compensation schemes. The fourth contribution proposes a distributed reconfiguration method for sensor and actuator networks. We consider systems where sensors and actuators cooperate to recover from faults. Reconfiguration is performed to achieve model-matching, while minimizing the steady-state estimation error covariance and a linear quadratic control cost. The reconfiguration scheme is implemented in a room heating testbed, and experimental results demonstrate the method's ability to automatically reconfigure the faulty system in a distributed and fast manner. The final contribution is a co-simulator, which combines the control system simulator Simulink with the wireless network simulator COOJA. The co-simulator integrates physical plant dynamics with realistic wireless network models and the actual embedded software running on the networked devices. Hence, it allows for the validation of the complete wireless networked control system, including the study of the interactions between software and hardware components. / <p>QC 20140929</p>