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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.
61

La captation de la jeune clientèle en matière de mode : le cas d'H&M et ZARA / The illegal securement of the young clientele in fashion : the case of H&M and Zara

Manga, Xavier 15 December 2010 (has links)
L’idée de cette thèse part du constat que les études de la mode fondées essentiellement sur le consommateur négligent les stratégies adoptées par les offreurs. C’est la raison pour laquelle cette étude s’articulera autour du travail de captation qu’opèrent les professionnels de la mode. Il existe une urgence à le penser car malgré tous les travaux en sciences sociales sur la mode, les recherches en sciences de l’information et de la communication consacrées à ce thème sont peu fréquentes voire inexistantes. Or une réflexion sur le concept d’une mode qui se veut captive soulève bien entendu des problématiques organisationnelles et communicationnelles. Car la mode est par définition ce qui se démode, son existence est éphémère. Roland Barthes l’a dit, la mode relève de l’imitation collective d’une nouveauté qui se renouvelle de façon permanente. Les acteurs qui suscitent son émergence sont aussi ceux qui la démodent chaque année en proposant une nouvelle. Il y a donc un renouvellement permanent non seulement des articles achetés par les consommateurs, mais aussi et surtout ceux proposés par les offreurs. La mode devient donc par définition une institution qui pousse le consommateur à l’achat permanent. ZARA et H&M, les deux géants mondiaux du prêt-à-porter, incarnent incontestablement cette situation. Leur captation consiste à proposer des collections de vêtements à la pointe de la mode, parfois directement inspirés des marques de luxe, le tout à des prix accessibles. Ces deux entreprises partagent peu de caractéristiques communes si ce n’est qu’elles distribuent des produits dits tendances à un public jeune / This Ph.D. dissertation is based on the observation that fashion studies that focus essentially on the consumer neglect the strategies adopted by providers. This is why the present study seeks to revolve around the work in illegal securement performed by the professionals of fashion. The issue requires immediate attention because, in spite of all the work in social sciences on fashion, researchers in Social Informatics dedicated to this theme are few or even non-existent. When it comes to theorising and questioning, the concept of a fashion wishing to captivate people naturally gives rise to organizational and communication problems. Because fashion is by definition that which puts things out of fashion; its existence is shortlived. Roland Barthes said that fashion stems forth from the collective imitation of a novelty which is constantly renewed. The actors who accelerate its emergence are also those that put it out of fashion every year by proposing another fashion. Thus there is permanent renewal of the articles bought by consumers and the direct implication of this is that the items proposed by providers are also renewed. Fashion thus becomes by definition an institution which precipitates the consumer into purchasing on a permanent basis. ZARA and H&M, the two world giants of ready-to-wear clothing, unmistakably embody this situation. Their illegal securement consists in proposing collections of clothing at the tip of fashion, sometimes directly inspired by luxury brands, and all this for affordable prices. These two companies characteristically little alike, except for the fact that they distribute so-called trendy products to a youthful public
62

Optimisation de catalyseurs pour la synthèse Fischer-Tropsch à partir de biosyngaz / Optimization of catalysts for Fischer-Tropsch synthesis from biosyngas

Butel, Aurore 18 December 2012 (has links)
Les travaux exposés dans ce manuscrit portent sur la préparation de catalyseurs monométalliques et bimétalliques à base de cobalt et de fer supportés sur alumine et silice pour la synthèse Fischer-Tropsch. Les catalyseurs notés xCoyFe/Al2O3 ou SiO2 ont une teneur massique globale de 10% pour différentes valeurs du rapport Co/Fe (x et y = 0 ; 2,5 ; 5 ; 7,5 ; 10 et x+y = 10%). Ainsi, ces catalyseurs ont été préparés par imprégnation à sec et caractérisés à différentes étapes de leurs préparations par différentes techniques de caractérisation physico-chimiques et spectroscopiques. L’axe majeur de cette étude concerne la germination des phases oxydes et la genèse des phases actives des matériaux mixtes, les échantillons monométalliques représentant des références solides pour cette étude. Par le biais de décompositions de spectres XANES et d’analyses de surface poussées, nous avons mis en avant la présence d’un alliage CoFe sur certains catalyseurs mixtes après calcination pour les faibles teneurs en cobalt. L’étude de la dispersion des phases oxydes a conduit à montrer que le fer est toujours mieux dispersé que le cobalt quelque soit le catalyseur ou le support utilisé. De plus, sur le support alumine les matériaux sont mieux dispersés, avec des tailles de cristallites plus faibles. L’originalité de ces travaux repose sur l’établissement d’une étude Operando, durant laquelle nous avons pu confirmer la particularité de nos matériaux mixtes CoFe. En effet, ces derniers, présentent une faible sensibilité aux phénomènes de frittage des particules métalliques de cobalt, contrairement aux matériaux monométalliques. Par ailleurs les matériaux mixtes présentent une activité intermédiaire à celle des matériaux classiques monométalliques pour la réaction Fischer-Tropsch. / The work exposed in this manuscript concerns the preparation of monometallic and bimetallic catalysts containing cobalt and iron supported on alumina and silica for the synthesis Fischer-Tropsch. The catalysts denoted xCoyFe/Al2O3 or SiO2 have a total mass content of 10% for various values of the Co/Fe ratio (x and y = 0; 2.5; 5; 7.5; 10 and x+y = 10%). Thus, these catalysts were prepared by wetness impregnation and were characterized at different stages of their preparations by various physicochemical and spectroscopic techniques of characterization. The major part of this study concerns the germination of the oxides phases and the genesis of the active phases of mixed materials. The samples monometallic represent the solid references for this study. From decompositions of XANES and XPS spectra, we proposed the presence of a CoFe alloy on mixed catalysts after calcination for the low cobalt contents. A better dispersion is observed for iron compared with cobalt whatever the support used. Moreover, on the alumina support, iron and cobalt are better dispersed with lower crystallite sizes. The originality of this work consists with the Operando study, which allowed to confirm the characteristic of our mixed materials CoFe. Indeed, the latter, have a low sensitivity of sintering of the cobalt metal particles, contrary to materials monometallic. These mixed materials present an intermediate activity compared with those of monometallic materials for the Fischer-Tropsch reaction.
63

Error correction techniques for ATM communications

Almulhem, Abdulaziz S. 24 August 2017 (has links)
Congestion in ATM communications is a significant issue as it can have a dramatic effect on critical or real-time data. Forward Error Correction (FEC) codes are one class of protocols to decrease this effect. Conventional FEC techniques have a uniform or constant error correction rate, which can result in poor bandwidth utilization. Therefore adaptive techniques are sought. The rationale is to have better bandwidth utilization when congestion occurs. In this thesis, we investigate the related work on FEC in ATM networks. Then we propose an adaptive FEC scheme based on RS codes. This proposed scheme is then studied in different types of environments, wireline and wireless. Simulations are also conducted to measure different performance issues concerning network resources and quality of service. Another crucial issue in ATM communications is security. The proposed FEC scheme has an added feature of being security ready. Moreover it has been shown that the security scheme is computationally secure. Such FEC scheme has significant impact on ATM network resources and switch capacity. This has been investigated further in this work. Switch architectures utilizing FEC schemes are also studied. / Graduate
64

Coupled-oscillator models for vortex-induced oscillation of a circular cylinder

Wood, Kelvin Norman January 1976 (has links)
The vortex-induced oscillation of a circular cylinder is modelled by a non-linear system with two degrees of freedom. The periodic lift acting on the cylinder due to the vortex-street wake is represented by a self-excited oscillator, which is coupled to the cylinder motion. Approximate solutions and stability criteria are presented which are valid over restricted intervals. Changes to the form of the coupled-oscillator model and its approximate solution are examined in order to improve the comparison between predicted model and experimental results. The changes are motivated by the study of experimental evidence, and by comparison with the known properties of similar systems of non-linear equations. Significant improvement in the coupled-oscillator model performance is obtained through the inclusion of an effective structural damping term which is dependent on wind speed and cylinder displacement. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate
65

Determining trip and travel mode from GPS and accelerometer data

Burgess, Aaron W. 03 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The use of Global Positioning Systems (GPS) and/or accelerometers to identify trips and transportation modes such as walking, running, bicycling or motorized transportation has been an active goal in multiple disciplines such as Transportation Engineering, Computer Science, Informatics and Public Health. The purpose of this study was to review existing methods that determined trip and travel mode from raw Global Positioning System (GPS) and accelerometer data, and test a select group of these methods. The study had three specific aims: (1) Create a systematic review of existing literature that explored various methods for determining trip and travel mode from GPS and/or accelerometer data, (2) Collect a convenience sample of subjects who were assigned a GPS and accelerometer unit to wear while performing and logging travel bouts consisting of walking, running, bicycling and driving, (3) Replicate selected method designs extracted from the systematic review (aim 1) and use subject data (aim 2) to compare the methods. The results were be used to examine which methods are effective for various modes of travel.
66

Archetypes of Feminine Creativity in the Works of Three Twentieth-Century Maritme Writers / Archetypes of Feminine Creativity in Maritime Fiction

Murphy, Marianne M. January 1997 (has links)
The ironic mode is currently a popular style of writing, as seen in the works being produced in the Maritimes. Three current Maritime writers who use this mode are Donna Smyth, David Adams Richards and Deborah Joy Corey. Though the works of these writers appear to be different from earlier pieces of Maritime writing, I suggest that this is not necessarily the case. These three writers are all concerned with the loss of tradition and community strength. I will show this through their treatment of the young women in their works, through their relationships with their partners, their elders, and the community at large. I also suggest that these works do, in fact, have strong ties with earlier writings. The women in these novels are ironic versions of Anne Shirley, L.M. Montgomery's beloved heroine. The romance of Anne may have turned into irony, but the young girl who tries to find a place for herself and her creativity in a rural Maritime region is still present. By comparing the similar events in the works of the late Twentieth Century and the Anne novels, I will show that, though Maritime writing is diverse, there is an interconnectedness in the writings produced from this region, regardless of the age. This allows for a universality in these various works that needs to be recognized as a significant contribution to Canadian--and world--literature. / Thesis / Master of Arts (MA)
67

Free Vibrations of Elastically Connected Stretched Beams with Applications To Carbon Nanotubes

Srinivas, Shirish January 2008 (has links)
No description available.
68

A UNIFIED SIMULATOR FOR MULTI-DOMAIN SIMULATION OF SYSTEMS USING DYNAMIC INTERPRETATION

PREMKUMAR, SRIDHAR 04 April 2007 (has links)
No description available.
69

Stress Intensity Factor Distributions in Bimaterial Systems - A Three Dimensional Photoelastic Investigation

Finlayson, Eric F. 27 February 1998 (has links)
Stress-freezing photoelastic experiments are conducted using two different sets of photoelastic materials to investigate stress intensity behavior near to and coincident with bimaterial interfaces. Homogeneous, bonded homogeneous, and bonded bimaterial single edge-cracked tension specimens are utilized throughout the investigation for comparative purposes. The first series of tests involves machined cracks obliquely inclined to the direction of far field tensile loading. Mixed-mode stress intensity factors are observed and quantified using a simplified analytical algorithm which makes use of experimentally measured data. In this series of tests, the bimaterial specimens consist of a photoelastic material bonded to the same material containing a moderate quantity of aluminum powder (for elastic stiffening purposes). Moderate yet similar increases in stress intensity factors are observed in bonded homogeneous and bonded bimaterial specimens, suggesting the presence of bondline residual stresses (rather than elastic modulus mismatch) as the primary contributing factor. The second series of tests involves the bonding of mutually translucent photoelastic materials whose elastic module differ by a ratio of approximately four to one. Cracks are placed both near and coincident to the bimaterial interfaces. Mode-mixity and increases in stress intensity are found only in bimaterial specimens whose cracks are placed close to the bondline. Using the materials from the first series of tests it is shown that the increases in these near-bondline experiments are due to thermal mismatch properties (incurred during the stress freezing cycles) rather than mechanical mismatch properties. / Master of Science
70

Commande sans capteur mécanique de la machine asynchrone pour la variation de vitesse industrielle / Sensorless induction machine control for industrial speed variation

Solvar, Sébastien 21 December 2012 (has links)
La machine asynchrone présente un intérêt majeur par rapport aux autres types de machines(courant continu, synchrone, ...), sa robustesse, son faible coût de fabrication etd'entretien en sont les principales raisons. Cependant ces avantages ont longtemps été inhibés par la complexité de la commande de celle-ci.De nos jours de nombreux industrielles proposent des variateurs de vitesse pour la machine asynchrone offrant à la fois la souplesse de contrôle, et la qualité de la conversion électromagnétique,naturellement obtenues jusqu'alors avec la machine à courant continu et de la machine synchrone.Depuis quelques années les industrielles font face à une nouvelle problématique, qui est la suppression du capteur mécanique dans le processus de régulation de vitesse de la machine asynchrone. Les travaux de cette thèse, effectués dansle cadre d'un support CIFRE entre l'entreprise GS Maintenance et le laboratoire ECS-Lab EA 3649, ont été orientésvers la réalisation d'un système de contrôle commande d'un variateur industrieldédié aux machines asynchrones sans capteur mécanique. De ce point de vue, l'objectifpremier du travail de thèse, est la conception des techniques de détermination des grandeursmécaniques (vitesse) de la machine asynchrone en utilisant comme seules mesuresles grandeurs électriques. Ces techniques, utilisées pour remplacer l'informationdonnée par les capteurs mécaniques, sont parfois appelées capteurs logiciels.Une attention particulière est donnée au fonctionnement de la machine asynchrone sanscapteur mécanique à basse vitesse. Dans un second temps l'objectif étant d'illustrer lesintérêts technologiques d'un observateur basé sur la technique des modes glissants dansle but d'intégrer celui-ci dans le système contrôle commande d'un variateur industriel. / Induction machine includes main interests compared with others electricals machines like brushed DC Motor,or synchronus electric Motor.Its robustness, its low cost manufacture, and maintenance are major reason of its success.However, for long time this advantages inhibited because of induction machine control complexity.Nowadays,many industrial propose speed drives for induction machine giving both control flexibility, and electromagnetic qualited conversion, naturally obtained with DC motor, and synchronus electric Motor.For several years now, many manufacturers face to a new problematic, wich is sensorless induction machine control.This thesis work, carried out in concert with the firm GS Maintenance and ECS-Lab EA 3649 laboratory under CIFRE financement.This work focused on conception plant dedicated to sensorless industrial speed drive control for induction machine.From this point of view, at first glance this work proposes technical strategies to identify mechanical induction machine variables, by using only electrical measurements.This strategies used to stand in for informations from a mechanical sensor, are the so called software sensor.Specific attention has been paid to induction machine sensorless working at very low speed. Secondly, we propose to illustrate the interest of a second order Sliding Mode Observer with final aim to be integrated into an industrial speed drive

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