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Context: During an influx of users during a short period of time there will most likely be more issues reported and discovered. This will lead to more work for the software developer team. Will this affect the development of the software and, if so, how?Objectives: Research how the large amount of new users Zoom received during the start of the covid-19 pandemic affects the development of new features, changes to old features, bug/issue resolving and scheduled updates/maintenance.Realization (Method): We are using case studies as our empirical method. We are looking through and analyzing the incident logs and release notes that are provided by Zoom. With the help of the acquired data we can make observations and compare them to find connections between the increase in user base and issues found/features released. Results: With the data we extracted from Zoom’s incident logs and release notes, we could conclude that the influx of new users increased the number of bugs/issues found.Scheduled updates and maintenance saw a decline as the covid outbreak continued.The total number of features added/changed were not diminished, but instead increased. Conclusions: From the results we conclude that an increased user base leads to more issues and the need to implement new un-scheduled features to improve scalability, which induced a lower focus on scheduled maintenance/updates.

I den här uppsatsen presenteras en studie av rörelsebaserad zoom (Device Movement Based Zoom) och nyp-zoomning (Pinch-zoom). Rörelsebaserad zoom innebär att användaren zoomar in genom att gå närmare ett objekt och zoomar ut genom att gå längre bort från det. Nyp-zoomning innebär att användaren zoomar genom nyp-gester med två fingrar på plattformens pekskärm. Syftet var att undersöka vilka likheter och skillnader som finns mellan de båda systemen ur ett användarperspektiv samt om engagemanget blir större när rörelserna blir större och användaren tvingas vara mer aktiv (med kroppen) vid interaktionen med systemet. De 24 deltagarna i studien testade två olika system, ett med vardera typen av zoom, och både kvalitativ och kvantitativ data samlades in genom enkäter. Resultatet visade att systemen hade nästan lika hög popularitet (på frågan; vilken av de två systemen skulle du föredra?). Däremot var svaren på frågan influerade av vilken telefon de hade till vardags. De som var vana att använda en telefon med knappar för navigering föredrog rörelsebaserad zoom i större utsträckning och de som var vana att använda pekskärm föredrog nyp-zoom i större utsträckning. Samma tendens syntes genomgående i all insamlad data. En tendens till att systemet med rörelsebaserad zoom gav högre engagemang hos användarna gick att se, men inga signifikanta skillnader fanns för hela gruppen. Tendensen var störst för delkategorierna upplevt engagemang och stabilitet. När deltagarna delades upp efter vilken mobiltelefon de var vana att använda syntes tendensen att de båda systemen ansågs mer likvärdiga i självskattat engagemang för de som sen tidigare var vana att använda nyp-zoom. De som inte var vana att använda nyp-zoom (deltagarna som använde knapptelefoner till vardags) märkte en större skillnad på systemen. Signifikanta skillnader sågs här under det totala engagemanget samt för delkategorierna stabilitet och upplevt engagemang. Värt att notera är att gruppstorleken var väldigt ojämn och antalet deltagare som var vana att använda en knapptelefon var väldigt lågt. Rörelsebaserad zoom upplevdes som naturlig och mer fri, medan nyp-zoom är smidigt att använda i vissa situationer då det inte kräver någon plats att gå omkring. En annan fördelmed nyp-zoom är att 3d-modellerna inte försvinner som de kan göra med den rörelsebaserade zoomen eftersom hela markören behöver vara i bild i enhetens kamera för att 3d-modellen ska visas. Däremot verkar nyp-zoom vara relativt svårt att använda för de som inte är vana vilket också syntes i de kvalitativa data. För att kunna säga mer hur väl resultatet kan generaliseras, till exempel med fokus på kroppslig interaktion och om något av sätten att zooma är att föredra över lag uppmuntras fler liknande studier.

This thesis focuses on early beginnings of a video conferencing platform Zoom, its development and enormous rise during the global pandemic of COVID-19 disease, and on its influence on users. It focuses particularly on millennials who are already familiar with this kind of technology. The aim of this work is primarily to determine the effects of Zoom, as a video conferencing platform, on user's activities because they were used to perform them in a physical contact with other people. However, due to restrictions resulting from epidemiological measures, participants were forced to move their activities to the online environment. The thesis focuses on answering these research questions: How do people's behaviour, perception of the situation and their self-presentation change when using Zoom in comparison to a face-to-face meeting? How have the activities of users changed while using Zoom, due to COVID-19, namely March to December 2020? How and for what reasons do users use Zoom? How do users perceive Zoom's affordances? In order to answer these questions, qualitative research was conducted using semi-structured in-depth interviews. These were attended by ten respondents who regularly use Zoom for a certain activity that was carried out in personal before the pandemic. Respondents were millennials,...

A dissertação apresenta um estudo de Beaubourg, Centre d\'art et culture Georges Pompidou (1977), último filme dirigido por Roberto Rossellini. A produção registra o início das atividades da instituição cultural parisiense cuja concepção arquitetônica e conceitual é abordada no primeiro capítulo. Desse contexto, o estudo avança para uma análise detalhada que identifica a variação dos registros adotados pelo filme diante dos espaços e situações apresentados no museu. A mobilidade do ponto de vista se sobressai como uma das características do filme, o que leva, nos próximos capítulos, ao estudo do movimento e da mobilidade de câmera no cinema rosselliniano. Atenção especial é concedida à Viagem à Itália (1954) no segundo capítulo e O Renascimento (1973), no capítulo final. Também são tratados alguns conceitos empregados pelo diretor, como \"microscópio\". No desenvolvimento, observamos como a mobilidade do plano abandona o contato direto com a realidade para se dirigir a um passado histórico reconstituído na artificialidade dos cenários e da encenação. O zoom emerge como recurso de mobilização da visão que explora a informação histórica para extrair dela a abstração do pensamento e da ideia. A conclusão retoma, em tom mais livre e interpretativo, a discussão de Beaubourg. / Beaubourg, Centre d\'art et culture Georges Pompidou (1977), the last film directed by Roberto Rossellini, is the main subject of this master thesis. In the first chapter, I discuss the architectural and institutional concept of the Pompidou Centre. From this context, the study advances towards a detailed analysis of the filmitself, considering whole range of different strategies employed during the filming. Camera mobility is one of its major characteristics, which leads, in the following chapters, to a broader understanding of movement and point of view in relation to filmic image. This discussion is subsidized by a detailed and somewhat auteurist study of two sequences from Journey to Italy (1954), in Chapter 2, and The Age of the Medici (1973) in the final chapter. I also describe some of the director´s unique concepts, such as the \"microscope\" and elaborate on the relations between historical representation and Rossellini\'s employment of zoom and tracking shots. Aiming to encounter the essential image, the director found means of approaching the abstractness of ideas. In the conclusion, an interpretative analysis of Beaubourg is resumed taking into account themes developed in previous chapters.

A dissertação apresenta um estudo de Beaubourg, Centre d\'art et culture Georges Pompidou (1977), último filme dirigido por Roberto Rossellini. A produção registra o início das atividades da instituição cultural parisiense cuja concepção arquitetônica e conceitual é abordada no primeiro capítulo. Desse contexto, o estudo avança para uma análise detalhada que identifica a variação dos registros adotados pelo filme diante dos espaços e situações apresentados no museu. A mobilidade do ponto de vista se sobressai como uma das características do filme, o que leva, nos próximos capítulos, ao estudo do movimento e da mobilidade de câmera no cinema rosselliniano. Atenção especial é concedida à Viagem à Itália (1954) no segundo capítulo e O Renascimento (1973), no capítulo final. Também são tratados alguns conceitos empregados pelo diretor, como \"microscópio\". No desenvolvimento, observamos como a mobilidade do plano abandona o contato direto com a realidade para se dirigir a um passado histórico reconstituído na artificialidade dos cenários e da encenação. O zoom emerge como recurso de mobilização da visão que explora a informação histórica para extrair dela a abstração do pensamento e da ideia. A conclusão retoma, em tom mais livre e interpretativo, a discussão de Beaubourg. / Beaubourg, Centre d\'art et culture Georges Pompidou (1977), the last film directed by Roberto Rossellini, is the main subject of this master thesis. In the first chapter, I discuss the architectural and institutional concept of the Pompidou Centre. From this context, the study advances towards a detailed analysis of the filmitself, considering whole range of different strategies employed during the filming. Camera mobility is one of its major characteristics, which leads, in the following chapters, to a broader understanding of movement and point of view in relation to filmic image. This discussion is subsidized by a detailed and somewhat auteurist study of two sequences from Journey to Italy (1954), in Chapter 2, and The Age of the Medici (1973) in the final chapter. I also describe some of the director´s unique concepts, such as the \"microscope\" and elaborate on the relations between historical representation and Rossellini\'s employment of zoom and tracking shots. Aiming to encounter the essential image, the director found means of approaching the abstractness of ideas. In the conclusion, an interpretative analysis of Beaubourg is resumed taking into account themes developed in previous chapters.

This dissertation presents the theoretical and experimental exploration of active reflective components specifically for large-aperture adaptive optical zoom systems. An active reflective component can change its focal length by physically deforming its reflecting surface. Adaptive optical zoom (AOZ) utilizes active components in order to change magnification and achieve optical zoom, as opposed to traditional zooming systems that move elements along the optical axis. AOZ systems are theoretically examined using a novel optical design theory that enables a full-scale tradespace analysis, where optical design begins from a broad perspective and optimizes to a particular system. The theory applies existing strategies for telescope design and aberration simulation to AOZ, culminating in the design of a Cassegrain objective with a 3.3X zoom ratio and a 375mm entrance aperture. AOZ systems are experimentally examined with the development of a large-aperture active mirror constructed of a composite material called carbon fiber reinforced polymer (CFRP). The active CFRP mirror uses a novel actuation method to change radius of curvature, where actuators press against two annular rings placed on the mirror's back. This method enables the radius of curvature to increase from 2000mm to 2010mm. Closed-loop control maintains good optical performance of 1.05 waves peak-to-valley (with respect to a HeNe laser) when the active CFRP mirror is used in conjunction with a commercial deformable mirror.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Aquesta tesi versa sobre l'estimació del moviment d'un robot mòbil a partir dels canvis en les imatges captades per una càmera muntada sobre el robot. El moviment es dedueix amb un algorisme prèviament proposat en el marc de la navegació qualitativa. Per tal d'emprar aquest algorisme en casos reals s'ha fet un estudi de la seva precisió. Per augmentar-ne l'aplicabilitat, s'ha adaptat l'algorisme al cas d'una càmera amb moviments d'orientació i de zoom.Quan els efectes perspectius no són importants, dues vistes d'una escena captades pel robot es poden relacionar amb una transformació afí (o afinitat), que normalment es calcula a partir de correspondències de punts. En aquesta tesi es vol seguir un enfoc alternatiu, i alhora complementari, fent servir la silueta d'un objecte modelada mitjançant un contorn actiu. El marc es el següent: a mesura que el robot es va movent, la projecció de l'objecte a la imatge va canviant i el contorn actiu es deforma convenientment per adaptar-s'hi; de les deformacions d'aquest contorn, expressades en espai de forma, se'n pot extreure el moviment del robot fins a un factor d'escala. Els contorns actius es caracteritzen per la rapidesa en la seva extracció i la seva robustesa a oclusions parcials. A més, un contorn és fàcil de trobar fins i tot en escenes poc texturades, on sovint és difícil trobar punts característics i la seva correspondència.La primera part d'aquest treball té l'objectiu de caracteritzar la precisió i la incertesa en l'estimació del moviment. Per avaluar la precisió, primer es duen a terme un parell d'experiències pràctiques, que mostren la potencialitat de l'algorisme en entorns reals i amb diferents robots. Estudiant la geometria epipolar que relaciona dues vistes d'un objecte planar es demostra que la direcció epipolar afí es pot recuperar en el cas que el moviment de la càmera estigui lliure de ciclorotació. Amb una bateria d'experiments, tant en simulació com reals, es fa servir la direcció epipolar per caracteritzar la precisió global de l'afinitat en diferents situacions, com ara, davant de diferents formes dels contorns, condicions de visualització extremes i soroll al sistema.Pel que fa a la incertesa, gràcies a que la implementació es basa en el filtre de Kalman, per a cada estimació del moviment també es té una estimació de la incertesa associada, però expressada en espai de forma. Per tal propagar la incertesa de l'espai de forma a l'espai de moviment 3D s'han seguit dos camins diferents: un analític i l'altre estadístic. Aquest estudi ha permès determinar quins graus de llibertat es recuperen amb més precisió, i quines correlacions existeixen entre les diferents components. Finalment, s'ha desenvolupat un algorisme que permet propagar la incertesa del moviment en temps de vídeo. Una de les limitacions més importants d'aquesta metodologia és que cal que la projecció de l'objecte estigui dins de la imatge i en condicions de visualització de perspectiva dèbil durant tota la seqüència. En la segona part d'aquest treball, s'estudia el seguiment de contorns actius en el marc de la visió activa per tal de superar aquesta limitació. És una relació natural, atès que el seguiment de contorns actius es pot veure com una tècnica per fixar el focus d'atenció. En primer lloc, s'han estudiat les propietats de les càmeres amb zoom i s'ha proposat un nou algorisme per determinar la profunditat de la càmera respecte a un objecte qualsevol. L'algorisme inclou un senzill calibratge geomètric que no implica cap coneixement sobre els paràmetres interns de la càmera. Finalment, per tal d'orientar la càmera adequadament, compensant en la mesura del possible els moviments del robot, s'ha desenvolupat un algorisme per al control dels mecanismes de zoom, capcineig i guinyada, i s'ha adaptat l'algorisme d'estimació del moviment incorporant-hi els girs coneguts del capcineig i la guinyada. / This thesis deals with the motion estimation of a mobile robot from changes in the images acquired by a camera mounted on the robot itself. The motion is deduced with an algorithm previously proposed in the framework of qualitative navigation. In order to employ this algorithm in real situations, a study of its accuracy has been performed. Moreover, relationships with the active vision paradigm have been analyzed, leading to an increase in its applicability.When perspective effects are not significant, two views of a scene are related by an affine transformation (or affinity), that it is usually computed from point correspondences. In this thesis we explore an alternative and at the same time complementary approach, using the contour of an object modeled by means of an active contour. The framework is the following: when the robot moves, the projection of the object in the image changes and the active contour adapts conveniently to it; from the deformation of this contour, expressed in shape space, the robot egomotion can be extracted up to a scale factor. Active contours are characterized by the speed of their extraction and their robustness to partial occlusions. Moreover, a contour is easy to find even in poorly textured scenes, where often it is difficult to find point features and their correspondences.The goal of the first part of this work is to characterize the accuracy and the uncertainty in the motion estimation. Some practical experiences are carried out to evaluate the accuracy, showing the potentiality of the algorithm in real environments and with different robots. We have studied also the epipolar geometry relating two views of a planar object. We prove that the affine epipolar direction between two images can be recovered from a shape vector when the camera motion is free of cyclorotation. With a battery of simulated as well as real experiments, the epipolar direction allows us to analyze the global accuracy of the affinity in a variety of situations: different contour shapes, extreme visualization conditions and presence of noise.Regarding uncertainty, since the implementation is based on a Kalman filter, for each motion estimate we have also its covariance matrix expressed in shape space. In order to propagate the uncertainty from shape space to 3D motion space, two different approaches have been followed: an analytical and a statistical one. This study has allowed us to determine which degrees of freedom are recovered with more accuracy, and what correlations exist between the different motion components. Finally, an algorithm to propagate the motion uncertainty at video rate has been proposed.One of the most important limitations of this methodology is that the object must project onto the image under weak-perspective visualization conditions all along the sequence. In the second part of this work, active contour tracking is studied within the framework of active vision to overcome this limitation. Both relate naturally, as active contour tracking can be seen as a focus-of-attention strategy.First, the properties of zooming cameras are studied and a new algorithm is proposed to estimate the depth of the camera with respect to an object. The algorithm includes a simple geometric calibration that does not require any knowledge about the camera internal parameters.Finally, in order to orientate the camera so as to suitably compensate for robot motion when possible, a new algorithm has been proposed for the control of zoom, pan and tilt mechanisms, and the motion estimation algorithm has been updated conveniently to incorporate the active camera state information.

There are inherent tradeoffs in size, weight, and adaptability for many military imaging systems. In some cases, active optical devices provide new alternatives external to the traditional trade-space. Applications of interest include remote wide-area surveillance, tactical use of high altitude and space-based sensors, remote navigation of unmanned ground and air vehicles, and night vision systems.My goal is to demonstrate that by augmenting or replacing static dioptric, catatropic, or catadioptric optical designs, mechanical complexity can be reduced while either maintaining or increasing performance in three areas:(1). Spectral Resolution(2). Spatial Resolution(3). MagnificationI present here three different imaging systems to showcase these capabilities.