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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Etude expérimentale et numérique des performances de la ventilation mécanique par insufflation : qualité de l’air intérieur dans les bâtiments résidentiels / Experimental and numerical study of the supply-only ventilation system performances : indoor air quality in residential buildings

Rahmeh, Mireille 04 July 2014 (has links)
La mauvaise qualité de l'air intérieur a été classée parmi les cinq principaux risques environnementaux sur la santé publique (EPA, 2013). La ventilation est une solution bien connue pour réduire la variété de contaminants qui pourraient être trouvés à l'intérieur de bâtiments résidentiels. Cependant, comme l'air propre est un facteur essentiel pour une vie saine et un bâtiment sain, une faible consommation d'énergie est essentielle pour une planète saine. Pour ces raisons, différentes recherches scientifiques sont menées pour l'amélioration des performances des systèmes de ventilation afin de créer un équilibre entre la distribution de l'air et la qualité de l'air intérieur d’un côté et le confort thermique et l'efficacité énergétique d’un autre côté. Un des systèmes de ventilation existants est la ventilation mécanique par insufflation (VMI). Son principe consiste à introduire mécaniquement de l’air neuf depuis l’extérieur, après l’avoir filtré et préchauffé. Les systèmes existant à ce jour en France introduisent l’air via un ou deux points d’insufflation (situés généralement au centre de l’habitation). Quant à l'évacuation de l’air vicié, celui-ci est véhiculé par les sorties naturelles installées dans chaque pièce de la maison. L’objectif de ce travail est tout d’abord d’étudier les performances de la ventilation par insufflation dans un environnement réel puis de trouver des pistes d’amélioration qui permettront d’atteindre une meilleure qualité de l’air intérieur. En se basant sur deux études préliminaires présentées par le chapitre II, on a installé un système à insufflation répartie (un point d’insufflation/pièce de vie) dans une maison réelle où l’on a mené des expérimentations. Des scénarios d’émission de polluant ont été effectués à l’aide de la technique de gaz traceur. L’étude a montré que, malgré un débit de ventilation global du système VMI inférieur à celui du système de référence (ventilation mécanique par extraction hygroréglable B), la VMI fournit des résultats satisfaisants. En outre, elle aide à lutter contre le confinement des chambres et à réduire à l'intérieur, les concentrations des particules provenant des sources extérieures. Une étude numérique est réalisée en utilisant un modèle aéraulique et de transfert de masse multizone. Les résultats ont montré un bon accord avec l'expérience et sont prometteurs pour l’avenir ; une étude paramétrique permettant d'améliorer la performance de la VMI vient parachever ce travail. / Poor indoor air quality has been ranked among the top five environmental risks on public health (EPA, 2013). The ventilation is a well-recognized solution for reducing the variety of contaminants that could be found inside residential buildings. However, as well as clean air is an essential factor for a healthy life and a healthy building, low energy consumption is significant for a healthy planet. For these reasons, scientific research are conducted to improve the performance of ventilation systems in order to obtain a balance in the controversial relationship between the air distribution and indoor air quality on the one hand and the thermal comfort and energy efficiency on the other hand. One of the existing ventilation systems is the Supply-Only Ventilation (SOV), known also as positive input ventilation (PIV). It functions by mechanically introducing fresh, filtered and preheated air into the center of the building. So far, the existing systems in France introduce air through one or two supply points (usually located in the center of the house). As for the evacuation, steal air goes out through natural vents installed in each room of the house. The aim of this study is to evaluate the performance of this system in terms of indoor air quality in a real environment and to find improvement field that will help in increasing the indoor air quality. Based on preliminary studies and on the airflow path principle required by French regulation, we decided to investigate a Multi Supply-Only Ventilation system (M-SOV). The idea is to have an insufflation point in the bedrooms and living room, while the free air outlets are located in the utility rooms (kitchen, bathroom and toilets). Different emission scenarios are experimentally simulated using tracer gas methods. The study shows that even though the flow rate of this system is lower than the extract only ventilation system (EOV), it provides satisfactory results. In addition, it helps fight against the confinement room and reduce the indoor particles concentrations originated from outdoor sources. A numerical study using a multizone airflow and contaminant transport model is performed. The numerical results show a good agreement with that of the experimental ones. Moreover, they are promising for the future parametric study in order to improve the SOV performance.
222

Výchova jedináčků / Upbringing of an only child

Fidlerová, Stanislava January 2015 (has links)
The thesis deals with the issue of singletons. Its main question is directed to the childhood of singletons and its importance for the whole life of a human. It wonders whether the childhood of singletons affects humans in adulthood, or in which areas and which way. The thesis is divided into two parts, theoretical and part of the research. In the first part basic terms are defined which constitute the basis for the second part of the work. The research part of the work is more extensive and forms the core of the thesis. It is a qualitative research. Biographical design, specifically the realistic biography, has been used as the most appropriate research plan. First, three interviews were made and processed - depth probes of the respondents who grew up as the singletons. The analysis of the probes divided the interview into three stages: childhood upbringing, the upbringing of their own children and self-education. After processing the individual parts of the research, the final synthesis revealed that the childhood of the respondents and the fact of being an only child had a significant impact on their overall life. It affected their childhood and also the following life stages. The biggest deficit of the singletons was in socialization, predominantly in the area of interpersonal relations and...
223

Investigating gameplay and gaming experience in an audio-only puzzle game using stressful versus calm ambience

Crépault Wibe, Catherine January 2021 (has links)
This study investigates if gameplay in an audio-only puzzle game differs when the player is feeling stressed or calm. This was done by conducting a test where 14 participants played an audio-only, puzzle game with two levels. One level containing stressful ambience and the other level containing calm ambience. The players were timed during the playtest and the results were analyzed. The results showed a significant decrease of played time in the level containing stressful ambience. The study has also investigated whether the participants preferred the level with the stressful ambience or the level with the calm ambience. This was done by asking the participants a series of questions. The participants' answers for these questions were analyzed by coding their answers and extracting keywords. The results showed no significant difference in player preference.
224

Approaches to accommodate remeshing in shape optimization

Wilke, Daniel Nicolas 20 January 2011 (has links)
This study proposes novel optimization methodologies for the optimization of problems that reveal non-physical step discontinuities. More specifically, it is proposed to use gradient-only techniques that do not use any zeroth order information at all for step discontinuous problems. A step discontinuous problem of note is the shape optimization problem in the presence of remeshing strategies, since changes in mesh topologies may - and normally do - introduce non-physical step discontinuities. These discontinuities may in turn manifest themselves as non-physical local minima in which optimization algorithms may become trapped. Conventional optimization approaches for step discontinuous problems include evolutionary strategies, and design of experiment (DoE) techniques. These conventional approaches typically rely on the exclusive use of zeroth order information to overcome the discontinuities, but are characterized by two important shortcomings: Firstly, the computational demands of zero order methods may be very high, since many function values are in general required. Secondly, the use of zero order information only does not necessarily guarantee that the algorithms will not terminate in highly unfit local minima. In contrast, the methodologies proposed herein use only first order information, rather than only zeroth order information. The motivation for this approach is that associated gradient information in the presence of remeshing remains accurately and uniquely computable, notwithstanding the presence of discontinuities. From a computational effort point of view, a gradient-only approach is of course comparable to conventional gradient based techniques. In addition, the step discontinuities do not manifest themselves as local minima. / Thesis (PhD)--University of Pretoria, 2010. / Mechanical and Aeronautical Engineering / unrestricted
225

Polymorphous Low-Grade Carcinoma

Klijanienko, Jerzy, Al-Abbadi, Mousa A. 09 March 2011 (has links)
No description available.
226

The Policy and Politics of Second Language Teaching

Wilson, Paige C. 04 December 2019 (has links)
No description available.
227

Scenanalys - Övervakning och modellering

Ali, Hani, Sunnergren, Pontus January 2021 (has links)
Självkörande fordon kan minska trafikstockningar och minska antalet trafikrelaterade olyckor. Då det i framtiden kommer att finnas miljontals autonoma fordon krävs en bättre förståelse av omgivningen. Syftet med detta projekt är att skapa ett externt automatiskt trafikledningssystem som kan upptäcka och spåra 3D-objekt i en komplex trafiksituation för att senare skicka beteendet från dessa objekt till ett större projekt som hanterar med att 3D-modellera trafiksituationen. Projektet använder sig av Tensorflow ramverket och YOLOv3 algoritmen. Projektet använder sig även av en kamera för att spela in trafiksituationer och en dator med Linux som operativsystem. Med hjälp av metoder som vanligen används för att skapa ett automatiserat trafikledningssystem utvärderades ett målföljningssystem. De slutliga resultaten visar att systemet är relativt instabilt och ibland inte kan känna igen vissa objekt. Om fler bilder används för träningsprocessen kan ett robustare och mycket mer tillförlitligt system utvecklas med liknande metodik. / Autonomous vehicles can decrease traffic congestion and reduce the amount of traffic related accidents. As there will be millions of autonomous vehicles in the future, a better understanding of the environment will be required. This project aims to create an external automated traffic system that can detect and track 3D objects within a complex traffic situation to later send these objects’ behavior for a larger-scale project that manages to 3D model the traffic situation. The project utilizes Tensorflow framework and YOLOv3 algorithm. The project also utilizes a camera to record traffic situations and a Linux operated computer. Using methods commonly used to create an automated traffic management system was evaluated. The final results show that the system is relatively unstable and can sometimes fail to recognize certain objects. If more images are used for the training process, a more robust and much more reliable system could be developed using a similar methodology.
228

Electro-Optic Range Signatures of Canonical Targets Using Direct Detection LIDAR

Ruff, Edward Clark, III 29 May 2018 (has links)
No description available.
229

Alliance in Flux: Turkey’s Alliance Behavior, from the Cold War to the Present, 1947-2010

Aydemir, Ilhan 20 July 2010 (has links)
No description available.
230

L'hybridation dans l'oeuvre de Jeannette Winterson / Hybridization in Jeanette Winterson's works

Mihajlovska, Lupka 16 November 2012 (has links)
Nous définissons l’hybridation littéraire comme la combinaison d’éléments a priori disparates aboutissant à la création d’un ensemble à la fois un et multiple, qui garde les traces de ses parties constitutives tout en étant autre, différent, nouveau. L’hybride englobe les sphères de représentation de ses éléments-parents tout en les dépassant. Par conséquent, l’hybridation tend vers l’extension de toutes les frontières, littéraires et culturelles, dans le but de nous offrir une vision du monde et du sujet toujours plus complète. Dans Oranges are not the Only Fruit, Sexing the Cherry, Written on the Body et The PowerBook de Jeanette Winterson, l’hybridation se manifeste à tous les niveaux du texte. L’hybridité physique et sexuelle des narrateurs est ainsi une des manifestations de leurs identités et vies plurielles et paradoxales. Ces hybrides incarnés (monstres, travestis ou androgynes) se construisant au fil de leurs histoires, qui s’inspirent toujours de récits antérieurs, narrateurs et narrations se démultiplient conjointement, s’entremêlent et se redéfinissent sans cesse. Le texte fluctue au gré de l’hybridation générique et de l’intertextualité. De l’entrecroisement de genres réalistes – tels que l’autobiographie, le récit historique ou le discours scientifique – et fictionnels – tels que le conte ou la romance – naît un hybride générique à résonances parodiques représentant la nature du sujet, de sa vie, de la réalité et de la vérité. Enfin, en hybridant des textes préexistants à des motifs personnels, l’auteur élabore une narration originale qui réécrit les schémas sexistes relayés par ses ancêtres et retranscrit sa vision de l’individu, du monde et de l’art. / We understand literary hybridization as the combination of seemingly different elements resulting in the creation of an entity that is simultaneously single and multiple. Indeed, while it is utterly other and new, the hybrid still shows the marks of its constituents. The hybrid incorporates its ‘parents’’ initial fields of representation while reaching beyond them. Consequently, hybridization is a process that pushes all boundaries, be they literary or cultural, to offer an ever more complete vision of the subject and his/her life. In Jeanette Winterson’s Oranges are not the Only Fruit, Sexing the Cherry, Written on the Body and The PowerBook, hybridization permeates every level of the text. Thus, the narrators’ physical and sexual hybridity is a manifestation of their plural and paradoxical identities. These hybrid creatures (monsters, transvestites or androgynous beings) build their identities through the stories they tell and that are always inspired by existing narratives. Therefore, the narrators and their narratives proliferate conjointly, intermix and redefine each other constantly. The shape of the text fluctuates with generic hybridization and intertextuality. Realistic narratives – such as autobiographical, historical or scientific discourses – and fictional ones – such as fairy tales or romances – interact to produce generic hybrids with parodic undertones that represent the nature of the subject, his/her life, reality and truth. Finally, by hybridizing existing texts and personal literary devices, the author elaborates original narratives that rewrite her ancestors’ sexist discourses and reflect how she perceives the individual, the world and art.

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