De même qu’un acteur, lors de chacune de ses apparitions, colore la pellicule cinématographique de toute son histoire, la présence d’une télévision à l’écran d’un film de fiction cinématographique est la source d’une infinité de significations historiques, esthétiques, sociologiques et politiques. De Rear Window (Fenêtre sur cour, Alfred Hitchcock, 1954) à Far From Heaven (Loin du paradis, Todd Haynes, 2002), cette thèse observe la façon dont les cinéastes américains critiquent les effets de la télévision sur le spectateur et sur la société, en adoptant une approche poéticienne, sociologique et historienne. Existe-t-il, comme Marshall McLuhan semble le penser, une essence des médias, et par conséquent, une essence de la télévision ? Si cette dernière en a une, est-elle négative ? La télévision apparaît-elle comme un « médium froid » (McLuhan) aux yeux des cinéastes américains ? Les cinéastes utilisent-ils la télévision comme point de comparaison pour affirmer le caractère artistique du cinéma ? Les films de nombreux cinéastes sont analysés (parmi lesquels Douglas Sirk, Billy Wilder, John Carpenter, Richard Fleischer, Sidney Lumet et David Cronenberg) pour permettre une réflexion sur ces questions. En filmant la télévision, les cinéastes créent un phénomène d’hypermediacy (Jay David Bolter et Richard Grusin), où s’affrontent réflexivité et fascination pour le médium. / As well as an actor brings with him his whole history each time he appears on the screen, television’s presence in a movie generates an infinite source of historical, aesthetical, sociological and political meaning. From Rear Window (Alfred Hitchcock, 1954) to Far From Heaven (Todd Haynes, 2002), this thesis observes the way american directors criticize the effects of television on the spectator and on society, adopting an approach inspired by poetics, sociology and history. Is there, as Marshall McLuhan seems to think, an essence of medias, and consequently, an essence of television ? If so, is it negative ? Does television appear as a « cool medium » (McLuhan) in the American director’s eye ? Do directors use television as a comparing point to assert the artistical quality of cinema ? Many directors’ movies are analyzed (including Douglas Sirk, Billy Wilder, John Carpenter, Richard Fleischer, Sidney Lumet and David Cronenberg) to allow a reflection on those questions. By filming television, directors create a hypermediacy phenomenon (Jay David Bolter et Richard Grusin), where reflexivity faces a fascination for the medium.

This thesis focuses on the issue of social networks. Social networks are one of the many types of social media, which are defined in the introduction of this thesis and described their characteristics. The thesis focuses on the options of two social networks in marketing and on the internet marketing in general. There are three criteria for the use of social net-works in companies -- sales promotion, publicity and communication. They are first de-scribed theoretically, analyzed in the environment of a particular company, the company Student Agency, and ultimately within these criteria suggested solutions to improve the use of social networks in the company. The aim of thesis is to define the possibilities of using social networks in companies to promote competitiveness, describe the options on real company and suggest possible improvements.

The aim of this thesis is to describe the process of biomass gasification using gas simulating the composition of flue gas – a mixture of oxygen, carbon dioxide and water vapor. In the research part of the thesis the issue of gasification with the focus on fluidized bed gasification and the effect of the gasification medium used on the gasification process is discussed. In the practical part the thesis deals with the design, realization and evaluation of the experiment on a real device. The aim of the experiment is to determine the effect of the exact composition of the mixture of these three media on the gasification process and on the quality of the gas generated. The aim is to find the optimum composition for obtaining gas with the highest possible lower heating value, which contains as little tar as possible. At the end of the work, the results from the experiment are presented and described.

This thesis deals with the process of wood drying. It is a method of removing excess water from wood. Drying can be divided into two basic types. The first type is natural drying. The material is dried without the presence of foreign energy source. This type depends only on climatic conditions and the amount of sunlight. Another type is artificial drying, where is pre-sent a foreign energy source, such as a biomass boiler. The second type is significantly faster than the first. The second type of drying uses a device called a wood dryer. There are a lot of types of wood dryers, the most widely used are kiln dryer, belt dryer, rotary drum dryer. In these devices, the thermal energy is transferred to the drying materials by the flowing warm drying medium (convection). The heat is transferred to the drying medium in a heat exchan-ger. Because the drying process is very energy demanding, it is appropriate to reduced the required energy. This can be done by regenerating heat and water. In the heat exchanger, part of the heat can be gained from the flowing exhaust medium. If a condensation of evaporated water in the exchanger occurs, the latent heat of the water is released. The gained heat is used to preheat the drying medium and thereby to reduce the required energy.

This master’s thesis deals with the process of biomass gasification using mixture of CO and O2 as gasification agent. First part describes the gasification process itself, used devices, gasification medium and its influence on the generated gas. Following section covers the experimental part of the work, which is focused on change properties of the generated gas using different ratios of CO2, O2, H2O and air in the gasification mixture. This part also includes processing and evaluation of the results.

Epitachophoresis is newly developed method, which allows to separate and concentrate analytes from large volumes of complex samples. Principle is based on isotachophoresis and utilize discontinuous electrolyte system. Different design of device is used, its round shaped and due to that acceleration of analytes zone migration occurs during separation towards centre of device and at the same time widening of zones happens. Focusation, concentration and separation of analytes between leading and terminating electrolyte progress from outer line of device towards its centre. It is necessary to stabilize this boundary to prevent mixing of leading and terminating electrolyte. Main target of this diploma thesis is optimization of epitachophoretic conditions, mainly electrolyte boundary stabilization options. Tested stabilizing media were agarose gels, foamed polymer disks and PDMS columns. All leading and terminating electrolyte boundary stabilizing media undergo several optimizations so the best option can be selected for concreate applications. DNA was used as a model analyte and the media with the highest recovery were selected. The best results offered NEEO and PFEG agarose gels and Dyneema foamed polymer with recovery over 70%. Another interesting alternative are PDMS columns, with their open structure that allow concentration of large volume analytes such as microorganisms.

This thesis focuses on the impressions, the news outlets presented to their readers about the presidential candidates, of the 2019 elections in Slovakia. The core of this thesis is a quantitative content analysis of the press releases, referring to the candidates. Our analysis covers the news in five Czech media sites: Aktualne.cz, Echo24.cz, iROZHLAS.cz, Mladá Fronta DNES and Právo. The analytical part is preceded by the theoretical basis and methodological fundamentals. The theoretical segment focuses on phenomenons such as the entrenching of the media outlets' agenda, the concept of reporting or news values or the condition of the journalistic objectivity. Ensuing chapters focus on the journalistic resources, the relationship of the media and the politicians and also reporting stereotypes. This theoretical part will later serve as a basis for research queries and hypotheses, formulated in the methodological section. This part then introduces the overall design of the research and it also contains a general characteristics of the media organisations. Next is the analytical part which includes several introductory pages, that offer an insight into the presidential elections. The research then analyses the sources the media used when reporting about the candidates, what impression did the...

Le maintien à domicile des personnes fragiles vivant seules est devenu une préoccupation majeure de santé publique dans nos sociétés modernes. Parmi les différents aspects scientifiques traités dans le domaine de la surveillance à domicile, nous nous intéressons à l’étude et à la proposition d’une solution permettant à des capteurs répartis de communiquer entre eux de façon optimale et adaptée aux contraintes spécifiques de l'application. Plus précisément, nous souhaitons construire un réseau sans fil courte portée constitué de plusieurs nœuds capteurs échangeant entre eux des données selon un protocole de communication de niveau MAC (contrôle d’accès au médium) qui optimise à la fois l’énergie, le délai de transmission et la perte d’informations. Pour cela, nous avons finement analysé les avantages et les limites des technologies WPAN (réseau local personnel sans fil) et des protocoles de communication actuellement utilisés en rapport aux exigences de notre application. Nous avons ensuite proposé une méthode d’accès au médium déterministe, adaptative et économe en énergie basée sur la couche physique IEEE 802.15.4 et une topologie maillée. Elle permet de garantir le délai d'acheminement des messages avec un risque de collisions très fortement limité, grâce à une réutilisation spatiale du médium dans un voisinage à deux sauts. Cette proposition a été caractérisée par modélisation et simulation à l'aide du simulateur de réseau OPNET. Nous avons alors implémenté les mécanismes proposés sur des dispositifs matériels et déployé un réseau de capteurs en situation réelle afin de vérifier la pertinence du modèle et évaluer la proposition selon différentes configurations de test / Monitoring behavior of the elderly and the disabled living alone has become a major public health problem in our modern societies. Among the various scientific aspects involved in the home monitoring field, we are interested in the study and the proposal of a solution allowing distributed sensor nodes to communicate with each other in an optimal way adapted to the specific application constraints. More precisely, we want to build a wireless network which consists of several short range sensor nodes exchanging data between them according to a communication protocol at MAC (medium access control) level that optimizes energy consumption, transmission time and loss of information. To achieve this objective, we have analyzed the advantages and the limitations of WPAN (wireless personal area network) technology and communication protocols currently used in relation to the requirements of our application. We then proposed a deterministic, adaptive and energy saving medium access method based on the IEEE 802.15.4 physical layer and a mesh topology. It ensures the message delivery time with strongly limited collision risk due to the spatial reuse of medium in the two-hop neighborhood. This proposal was characterized by modeling and simulation using the OPNET network simulator. We then implemented the proposed mechanisms on hardware devices and deployed a sensors network in real situation to verify the accuracy of the model and evaluate the proposal according to different test configurations

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La tendance actuelle des réseaux de capteurs sans fil est d'avoir un seul réseau supportant plusieurs applications et fournissant plusieurs QoS. Dans cette thèse, nous étudions les techniques de cross-layering afin d'améliorer les performances et de fournir de la QoS. Tout d'abord, nous généralisons le concept de la méthode d'accès MaCARI en proposant une architecture multi-couches où plusieurs combinaisons de protocoles MAC-routage sont utilisées. Une file d'attente est associée à chaque combinaison, et chaque combinaison est activée pour une période précise. Le but est de profiter de ces combinaisons pour offrir différentes QoS. Cependant, cette architecture cause un problème de dimensionnement des périodes, ce qui a un impact sur les performances du réseau. Nous proposons, ensuite, des techniques de cross-layering en échangeant les paquets entre les différentes files d'attente afin de résoudre le problème de dimensionnement. Durant sa période, chaque combinaison traite tous les paquets de sa file d'attente ainsi que les paquets des files d'attente d'autres périodes. Nous montrons par simulation que notre approche améliore les performances du réseau.