La complexification des intégrations sur les puces électroniques et la course à la miniaturisation sont les deux moteurs actuels de la microélectronique. Les limites optiques de la lithographie sont déjà atteintes depuis longtemps. Ainsi, la fabrication doit aussi être contrôlée de plus en plus étroitement afin d’éviter des variabilités qui nuiraient au bon fonctionnement du produit. Cette thèse présente une approche holistique du contrôle d’un des paramètres les plus importants de la photolithographie : le focus. Celui-ci est directement lié à la qualité de l’image transférée dans la résine photosensible pendant l’exposition. Son contrôle est donc primordial. Les sources de variabilités du focus sur le wafer sont multiples et diverses mais le cas particulier de la topographie du substrat a été privilégié dans cette étude. L’approche holistique de cet effet en particulier a conduit à l’utilisation d’outils de « data mining » telle la régression par la méthode des moindres carrés partiels qui a permis de pointer les principales causes de cette topographie, de créer un modèle prédictif de la topologie mais aussi d’évaluer des solutions d’améliorations comme l’amélioration des corrections qu’effectue le scanner permettant un meilleur contrôle généralisé de toutes les technologies sans toutefois changer l’intégration et le design ou encore la mise en place d’une méthode qui permet d’évaluer les erreurs de focus sur le wafer sans pour autant avoir recours à des mesures intensives sur silicium. D’autres solutions permettent de corriger les facteurs de risques à la source en modifiant le design afin de limiter la formation de la topologie de surface / The increasing complexity in chip integration (co-integration, increasing diversity of matérials…) and the race to dimension shrinkage are the two main drivers of research in microelectronics today. The optical limitations of lithography have been reached some years ago so that double patterning is now a typical process flow in production and helps reducing pattern size and increasing design density. Because of these, the manufacturing itself needs to be more tightly controlled in order to avoid marginalities. Which will affect the chip operation. The cross-effects between these elements are more numerous and their ratio in the total budget is larger whereas the needs for tighter process control are rising. This thesis presents a holistic approach of the control of one of the main parameters for photolithography: focus. It is directly linked to the quality of the image transferred into the photoresist during exposure. Its control is then essential. Variability sources for focus are manifold and diverse: laser, mask, optical column, servo-controllers, wafer flatness, integration, design, substrate reflectivity, material quality etc. All these are added to each other, leading to the creation of defects which can be catastrophic such as shorts. The first objective of this work was to show current challenges raised by STMicroelectronics new technologies, specifically photolithography-wise and focus-wise. A budget breakdown of two critical processes (Metal line patterning in 28nm FD-SOI and Contact patterning for 14nm FD-SOI) has been established which gives the impact of every effect. The product layout effects were evaluated to represent up to 20% of the complete budget and 50% of its intra-chip component. Topography contributes to a large part of these effects and offline measurements showed up to 32nm 3s of height variation in a single field. This may lead to local defocuses of the same order of magnitude. The usable depth of field being about 60 to 70nm for the studied layers, it is clear that focus control is really tight here. The holistic approach of topology leaded to the use of data mining tooling as PLS regression (Partial least Square). It allowed the highlighting of main causes of topography, the creation of a predictive model of topology and the evaluation of several improvement solutions. One may distinguish “palliative” and “curative” solutions. In the first category, on may put scanner levelling improvements which might be effective for every technology without any modification to make on integration and design. The emulated wafer map methodology providing on-product focus non-uniformities without any measurements is also a solution for investigation. “Curative” solutions may concern the mitigation of risk factors by modifying the design topography built-up main factors

No description available.

The aim of this study was to investigate the effect of attentional focus on football performance. 20 junior elite football players participated in a repeated measure experiment where the effects of external focus and internal focus (compared to a control condition with no instructions regarding attentional focus) in a football related performance was investigated. The participants got to do an obstacle course three times, one with no instructions regarding focus of attention, one with internal focus and one with external focus. Significant effect of focus was found in two out of three dependent variables, passing points and cone touches, but no effect on time taken to finish the obstacle course. The participants got more points in passing and touched less cones in the obstacle course when having an external focus (with medium to strong effect sizes) compared to both internal focus and no instructions regarding focus. There were no differences in performance between internal focus and no instructions. The result in this study indicates that having external focus could enhance performance for junior elite football players, even though more research is needed on the subject for senior football players.

The purpose of this research is to develop a process and an algorithm to create a 3D model of the surface a part. This is accomplished using a single camera and a CNC machine as a movable stage. A gradient based focus measure operator written in MATLAB is used to process the images and to generate the surface model. The scopes of this research are image processing and surface model generation as well as verifying part accuracy. The algorithm is able to create a rough surface model of a photographed part, and with careful calibration in a limited number of scenarios has been used in checking part z dimensions.

Time reversal is a method often used to focus sound to a desired location, and works best in a reverberant environment. The effect of focus location within a reverberant environment is presented first, revealing that proximity to reflecting surfaces has a significant effect on the amplitude of the focus both experimentally and when using a modal summation model. These effects are a primary component to creating focus signals at high amplitudes. High-amplitude focusing experiments show that when multiple sources are used simultaneously to generate a focus, a peak amplitude pressure spike of 200 dB can be achieved in air. A pressure spike of this amplitude has multiple nonlinear characteristics, and an investigation into the spatiotemporal features and harmonic content of these signals was conducted. The peak amplitude of the focus signal also increases in amplitude nonlinearly as the loudspeaker volume is linearly increased. This nonlinear increase is the primary subject of investigation in this work. Experimental and computational methods are implemented in order to understand the mechanisms driving the nonlinear increases observed when the sources are combined acoustically as opposed to linear superposition of the contributions from each sound in post-processing. Finally, models of converging high-amplitude waves are generated using the k-Wave© package for MATLAB©. These show a similar nonlinear increase in amplitudes, supporting the hypothesis of a Mach wave coalescence. A COMSOL© finite element model allows visualization of the converging waves with Mach stems forming in free space to cause the nonlinear amplification.

[pt] Contexto: As operações de aprendizagem automática (MLOps) surgiram como um conjunto de práticas que combina desenvolvimento, testes e operações para implementar e manter aplicações de aprendizagem automática. Objetivo: Nesta dissertação, iremos avaliar os benefícios e limitações da utilização dos princípios de MLOps no contexto de modelos supervisionados online, que são amplamente utilizados em aplicações como a previsão meteorológica, tendências de mercado e identificação de riscos. Método: Aplicámos dois métodos de investigação para avaliar os benefícios dos MLOps para aplicações de aprendizagem automática online supervisionada: (i) desenvolvimento de um projeto prático de aprendizagem automática supervisionada para aprofundar a compreensão do problema e das possibilidades de utilização dos princípios MLOps; e (ii) duas discussões de grupo de foco sobre os benefícios e limitações da utilização dos princípios MLOps com seis programadores de aprendizagem automática experientes. Resultados: O projeto prático implementou uma aplicação de aprendizagem automática de regressão supervisionada utilizando KNN. A aplicação utiliza informações sobre as rotas das linhas de autocarros públicos do Rio de Janeiro e calcula a duração da viagem de autocarro com base na hora de partida do dia e no sentido da viagem. Devido ao âmbito da primeira versão e ao facto de não ter sido implementada em produção, não sentimos a necessidade de utilizar os princípios MLOps que esperávamos inicialmente. De facto, identificámos a necessidade de apenas um princípio, o princípio do controlo de versões, para alinhar as versões do código e dos dados. O grupo de discussão revelou que os programadores de aprendizagem automática acreditam que os benefícios da utilização dos princípios MLOps são muitos, mas que não se aplicam a todos os projectos em que trabalham. A discussão revelou que a maioria dos benefícios está relacionada com a prevenção de passos manuais propensos a erros, permitindo restaurar a aplicação para um estado anterior e ter um pipeline robusto de implementação automatizada contínua. Conclusões: É importante equilibrar as compensações do investimento de tempo e esforço na implementação dos princípios de MLOps, considerando o âmbito e as necessidades do projeto. De acordo com os especialistas, esse investimento tende a compensar para aplicativos maiores com implantação contínua que exigem processos automatizados bem preparados. Por outro lado, para versões iniciais de aplicações de aprendizagem automática, o esforço despendido na implementação dos princípios pode alargar o âmbito do projeto e aumentar o tempo de execução. / [en] Context: Machine Learning Operations (MLOps) has emerged as a set of practices that combines development, testing, and operations to deploy and maintain machine learning applications. Objective: In this dissertation, we will assess the benefits and limitations of the use of MLOps principles in the context of online supervised models, which are widely used in applications such as weather forecasting, market trends, and risk identification. Method: We applied two research methods to assess the benefits of MLOps for supervised online machine learning applications: (i) developing a practical supervised machine learning project to deepen the understanding of the problem and of the MLOps principles usage possibilities; and (ii) two focus group discussions on the benefits and limitations of using the MLOps principles with six experienced machine learning developers. Results: The practical project implemented a supervised regression machine learning application using KNN. The application uses information on Rio de Janeiro s public bus line routes and calculates the bus trip duration based on the trip departure time of the day and trip direction. Due to the scope of the first version and given that it was not deployed into production, we didn t feel the need to use the MLOps principles we were expecting at first. Indeed, we identified the need for only one principle, the versioning principle, to align versions of the code and the data. The focus group revealed that machine learning developers believe that the benefits of using MLOps principles are many but that they do not apply to all the projects they worked on. The discussion brought up that most of the benefits are related to avoiding error-prone manual steps, enabling it to restore the application to a previous state, and having a robust continuous automated deployment pipeline. Conclusions: It is important to balance the trade-offs of investing time and effort in implementing the MLOps principles considering the scope and needs of the project. According to the experts, this investment tends to pay off for larger applications with continuous deployment that require well-prepared automated processes. On the other hand, for initial versions of machine learning applications, the effort taken into implementing the principles might enlarge the scope of the project and increase the time needed to deploy a first version to production.

Genom att analysera tidigare försök till effektivt digitalt lärande och problem som hör därtill så spekulerar vi kring hur detta forskningsområde och denna designyta kan utvecklas i framtiden. Vi simulerar upplevelsen av att studera och lära sig i ett riktigt klassrum, under riktiga omständigheter, virtuellt. I undersökningen har deltagarna fått möjlighet att testa på att, med hjälp av ett VR-headset och applikationen utvecklad i undersökningens syfte, se på två olika videor. Applikationen låter dig se och lyssna på en lektion eller video i ett rum som simulerar ett riktigt klassrum, och kombinerar de digitala funktionerna av att spela in, pausa och hoppa i tidslinjen av innehållet simultant till det fysiska mediet av att klottra. Resultaten visar på att deltagarna kommit ihåg mer information under tiden de fått möjligheten att klottra än de gjorde i samma upplevelse utan ett simulerat fysiskt medium, oavsett innehållet av klottrandet eller vad det har föreställt. / By analyzing past attempts at streamlined digital teaching and learning, and the problems therewith, we speculate as to the future of this field and the path of its development. We simulate the experience of studying and learning in a real classroom, under real circumstances, virtually. Participants have been given the opportunity to, with the help of a VR-headset and the application developed for the purpose of this research, look at two separate videos. The application allows you to watch and listen to a lesson or a video in a room simulating a real classroom, and it combines the digital functionality of recording, pausing and jumping in the timeline of the content, while simultaneously being offered the physical medium of doodling. Results show that participants have had a better recollection of the content during which they were doodling than that during which they were not, regardless of the content of the doodling or what it depicts.

Yes / Background: A range of myopia management (MM) contact lenses are becoming available to practitioners. These lenses are designed to slow myopia progression and axial elongation. This study explored the initial experience of participants wearing daily disposable MM contact lenses to investigate established factors previously associated with successful lens wear. Methods: This was a prospective, double-masked, crossover study. Twenty participants aged 18–30 years old were assigned to wear two daily disposable MM lenses in a randomised order. Visual acuity, contrast sensitivity, and amplitude/lag of accommodation were assessed at baseline, post-insertion, and after 2 and 6 h of lens wear. Self-reported lens comfort and vision quality were recorded at the same timepoints, and at 10 h post-insertion. Pairwise comparisons were performed between the two lenses at each timepoint, as well as assessing changes throughout wear. The relationship of the measured parameters to overall lens satisfaction was also assessed. Results: There were no significant differences between the two MM lenses at any timepoint for any of the participant-reported parameters, including overall satisfaction. A small difference in visual acuity was noted at 6 h post-insertion, although this is unlikely to be clinically significant. Comfort decreased throughout the day, most notably at 10 h post-insertion. A moderate positive correlation was observed between participant-reported visual quality and overall satisfaction. A similar pattern was seen for comfort and overall satisfaction. Self-reported vision quality and measured visual acuity were poorly correlated, highlighting the benefit of subjectively assessing the quality of vision with these lenses. Conclusions: The participants demonstrated comparable measures across a range of measures between the two MM lenses. Notably, half of the participants demonstrated a clear lens preference, although the preferred lens varied between individuals. Candidates for MM may benefit from trialling more than one MM lens design, to maximise initial wearing satisfaction. / This project was supported by the British Contact Lens Association Summer Research Scholarship.

Yes / Background: Soft contact lenses have been developed and licensed for reducing myopia progression. These lenses have different designs, such as extended depth of focus (EDOF) and dual focus (DF). In this prospective, doublemasked, cross-over study, different lens designs were investigated to see whether these had impact on accommodative microfluctuations and eye movements during reading. Methods: Participants were fitted with three lenses in a randomised order; a single vision (SV) design (Omafilcon A2; Proclear), a DF design (Omafilcon A2; MiSight), and an EDOF lens design (Etafilcon A; NaturalVue),. Accommodative microfluctuations were measured at 25 cm for at least 60s in each lens, using a Shin-Nippon SRW-5000 autorefractor adapted to continuously record accommodation at 22Hz. Eye movement data was collected with the Thomson Clinical Eye Tracker incorporating a Tobii Eye bar. Eye movements include fixations per row, fixations per minute, mean regressions per row, total number of regressions, and total rightward saccades. Accommodation data was analysed using power spectrum analysis. Differences between the lenses were compared using a related sample two-way Friedman test. Results: Twenty-three participants (18–29 years) were recruited to take part. The average mean spherical error was − 2.65D ± 1.42DS, with an average age of 23.4 ± 3.5 years. No significant difference for accommodative microfluctuations was found. Significant differences were found for fixations per row (P = 0.03), fixations per minute (P = 0.008), mean regressions per row (P = 0.002), and total number of regressions (P = 0.002), but not total rightward saccades (P = 0.10). Post-hoc analysis indicated the EDOF lens results were significantly different from the other lenses, with more regressive eye movements observed. Conclusions: Regressive saccades appear to increase when wearing EDOF lens designs, which may impact visual comfort. Further studies in children, over a longer period of adaptation are necessary to assess the potential impact of this finding on daily reading activities in children. / This project was supported by the British Contact Lens Association Summer Studentship Award (recipient Muskaan Hussain).

Dans le cadre de l'acquisition de l'information de profondeur de scènes texturées, un processus d'estimation de la profondeur basé sur la méthode de reconstruction 3D « Shape from Focus » est présenté dans ce manuscrit. Les deux étapes fondamentales de cette approche sont l'acquisition de la séquence d'images de la scène par sectionnement optique et l'évaluation de la netteté locale pour chaque pixel des images acquises. Deux systèmes d'acquisition de cette séquence d'images sont présentés ainsi que les traitements permettant d'exploiter celle-ci pour la suite du processus d'estimation de la profondeur. L'étape d'évaluation de la netteté des pixels passe par la comparaison des différents opérateurs de mesure de netteté. En plus des opérateurs usuels, deux nouveaux opérateurs basés sur les descripteurs généralisés de Fourier sont proposés. Une méthode nouvelle et originale de comparaison est développée et permet une analyse approfondie de la robustesse à différents paramètres des divers opérateurs. Afin de proposer une automatisation du processus de reconstruction, deux méthodes d'évaluation automatique de la netteté sont détaillées. Finalement, le processus complet de reconstruction est appliqué à des scènes agronomiques, mais également à une problématique du domaine de l'analyse de défaillances de circuits intégrés afin d'élargir les domaines d'utilisation / In the context of the acquisition of depth information for textured scenes, a depth estimation process based on a 3D reconstruction method called "shape from focus" is proposed in this thesis. The two crucial steps of this approach are the image sequence acquisition of the scene by optical sectioning and the local sharpness evaluation for each pixel of the acquired images. Two acquisition systems have been developed and are presented as well as different image processing techniques that enable the image exploitation for the depth estimation process. The pixel sharpness evaluation requires comparison of different focus measure operators in order to determine the most appropriate ones. In addition to the usual focus measure operators, two news operators based on generalized Fourier descriptors are presented. A new and original comparison method is developped and provides a further analysis of the robustness to various parameters of the focus measure operators. In order to provide an automatic version of the reconstruction process, two automatic sharpness evaluation methods are detailed. Finally, the whole reconstruction process is applied to agronomic scenes, but also to a problematic in failure analysis domain aiming to expand to other applications