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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.
131

Le capital de mode : un nouveau concept pour comprendre et expliquer le comportement du consommateur de produits de mode / Fashion Equity : a new concept to understand and explain the consumer behavior towards fashion products

Le Bon, Caroline 23 June 2011 (has links)
La mode est partout et recouvre de nombreux secteurs, produits, et concerne de près ou de loin de nombreux individus. La fidélité aux produits de mode soulève différentes interrogations concernant ce qui incite le consommateur à les choisir, à rester fidèle à la mode et ceci malgré les changements incessants propres à celle-ci. Cependant nous n’avons pas relevé d’approche se rapportant à une explication de cette fidélité basée sur les valeurs apportées par la mode au niveau du produit et indépendamment des caractéristiques physiques et/ou des fonctionnalités de ce dernier. Au cours de cette recherche notre intérêt portera donc sur la compréhension des raisons poussant l’individu à s’associer à la mode. L’analogie par rapport au capital de marque (Keller, 1993), nous incite à penser que de manière similaire à la marque, la mode apporte de la valeur ajoutée au produit en comparaison à ceux jugés non mode. Nous introduirons le concept de capital de mode afin d’appréhender cette valeur ajoutée que la mode apporte aux produits. L’analyse qualitative menée confirme les valeurs ajoutées par la mode au produit que nous avons identifiées. De plus, les résultats de l’étude empirique menée auprès de suiveurs montrent, comme cela était supposé, que l’attachement joue un rôle médiateur dans la relation liant le capital de mode à la fidélité au niveau du vêtement et du téléphone mobile. Les valeurs ajoutées par la mode contribuent donc au développement d’un attachement et d’une fidélité de la part de l’individu à l’égard de ce qui est mode dans les catégories de produits étudiés. Notre recherche propose ainsi une explication de la fidélité à la mode grâce au capital de mode. / Fashion transcends domains, applies to almost any kind of product and concerns many people. The loyalty towards fashion products raises questions about why and how products appeal to consumers, despite their constantly varying attributes. Furthermore, little is known about how fashion trends may induce people to stay loyal to fashion products. We are not aware of any other approach that explains consumer behavior on the basis of fashion value per se, that is, that a fashion product is of interest because it is explicitly perceived as a fashion item. We propose a new explanation for consumers’ interest in and loyalty to fashion products. Extending the concept of consumer-based brand equity (Keller, 1993), we propose that consumer-based fashion equity may account for the role that fashion plays, in determining consumers’ loyalty—similar to the way brand equity explains why high equity brands appeal more to consumers than do low equity ones. We introduce the concept of fashion equity to account for the value that fashion adds to products. The exploratory study conducted with followers confirms the values added by fashion to product and the results of our analysis demonstrates that attachment is a mediator in the relationships fashion equity-attachment-loyalty for fashion clothe and mobile phone. Therefore, these values contribute to the development of fashion attachment and fashion loyalty. Our research suggests an explanation of loyalty towards fashion thanks to fashion equity.
132

Étude des attentes et de la perception du consommateur sur les marques de mode éthique, et de leur lien avec les paramètres textiles selon les méthodes Kansai et de l'ACV / Study of consumer expectation and perception on ethical fashion brands and their relationship with textile parameters by using Kansai and LCA approaches

Wagner, Melissa Monika 30 September 2019 (has links)
La mode éthique, aussi appelée mode écologique, durable ou lente, a évolué mais reste un marché de niche. Selon des études de marché, l'éco-conception apparaît en termes d'image respectueuse de l'environnement ou d'attractivité qui ne répond pas aux attentes des consommateurs. Une conception de produit réussie doit répondre aux attentes et aux émotions des consommateurs. La perception du consommateur et les connaissances des experts doivent être associées au processus d’évaluation de la mode éthique. Les travaux de recherche actuels sont principalement basés sur l'exploration des valeurs de la mode éthique à partir d'une entreprise traditionnelle, d'un marketing ou d'une conception en perspective. À la différence de cette approche, l’étude proposée a été intégrée aux visions quantitatives des consommateurs et respectueuses de l’environnement, ainsi qu’à une analyse détaillée de la démarche de conception écologique. Cette approche a déjà été étudiée et peut être réduite à l’écart entre les attentes et les valeurs de la mode éthique. Dans ce contexte, de nouveaux produits de design éco-mode seront acceptés sur différents marchés de consommation.Dans cette thèse, le projet de recherche présenté vise à caractériser qualitativement et quantitativement les attentes des consommateurs et leur perception de la mode éthique dans une série de produits textiles représentatifs et leurs relations avec les paramètres de conception des produits concernés. À cette fin, nous proposons une évaluation de l'acquisition de données et une analyse des données humaines. Ces approches sont les suivantes: premièrement, nous proposons une détermination du groupe de discussion des consommateurs et une enquête qualitative. Deuxièmement, nous concevons deux expériences sensorielles avec perception quantitative de la perception et des émotions humaines en utilisant l’ingénierie sensorielle et l’ingénierie Kansei, en acquérant des données de perception expertes sur les paramètres de conception et en utilisant la logique floue afin de caractériser de manière plus objective la relation. De plus, nous anticipons un écart entre l’ACV réelle et la perception humaine. Nous avons comparé les impacts réels d'un produit de mode avec l'analyse du cycle de vie (ACV). / Ethical fashion, also called eco, sustainable or slow fashion, has increasingly evolved but remains a niche market. According to marketing studies, the eco-design appearance in terms of environmentally-friendly image or attractiveness fails to support consumer expectations. A successful product design should meet consumer expectations and emotions. Consumer perception and expert knowledge needs to be involved within the evaluation process of ethical fashion. The current research work is mostly based on the exploration of ethical fashion values from a traditional business, marketing or design perspective. Different from this approach, the proposed study originally integrates quantitative consumer emotional and perceptual values towards environmentally-friendly, and detailed analysis into the eco-fashion design approach. This approach has not been studied before and can minimize the gap between expectations and design values of ethical fashion. In this context, new eco-fashion design products will receive broader acceptance in various consumer markets.In this thesis, the research project presented aims at qualitatively and quantitatively characterizing consumer expectation and consumer perception on ethical fashion in a series of representative textile products and their relations with concerned product design parameters. For this purpose, we proposed four evaluation approaches for acquiring and analyzing relevant human data. These approaches include the following: Firstly, we proposed a consumer focus group determination and a survey questionnaire development in order to characterize the relationship between consumer expectations and design parameters qualitatively. Secondly, we designed two sensory experiments to quantitatively characterize human perception and emotions by using sensory engineering and Kansei engineering including the acquisition of expert perceptual data on design parameters and using fuzzy logic in order to characterize more objectively the relationship. Furthermore, we anticipated a gap between real LCA and human perception. We compared the real impacts of a fashion product obtained with life cycle assessment (LCA) methodology with human perception of ethical through the visual appearance of fashion products.
133

Design Of A Three Phase AC-Side Common-Mode Inductor

Avyay Sah (15348511) 26 April 2023 (has links)
<p>In recent years, switch-mode power electronic converters have gained considerable popularity</p> <p>because of their compact size and high switching frequencies. This makes them</p> <p>suitable for power processing in various applications, including photovoltaic systems and</p> <p>electric vehicles. However, their high switching frequency capabilities have a drawback. A</p> <p>high-frequency common-mode voltage coupled with the switching of the power converters</p> <p>excites the parasitic capacitances of the system. It leads to the flow of common-mode current.</p> <p>Since the common-mode current flows through an unintended path, it can potentially</p> <p>interfere with the performance of system components. Passive filters can be used to mitigate</p> <p>common-mode currents. Using a common-mode inductor in conjunction with strategically</p> <p>placed capacitors makes it possible to limit the flow of common-mode current.</p> <p><br></p> <p>As part of this work, passive mitigation of common-mode current will be investigated in</p> <p>a variable frequency drive system. In this regard, the process of designing a three-phase ac</p> <p>common-mode inductor is explained. As a first step, a mitigation strategy is proposed and</p> <p>described. Next, the issue of self-capacitance of the inductor is discussed. Afterwards, the</p> <p>ac common-mode inductor is designed using a multi-objective optimization-based approach.</p> <p>Following this are the design results, concluding the dissertation.</p>
134

A manufacturing failure mode avoidance framework for aerospace manufacturing

Goodland, J., Campean, Felician, Caunce, A., Victory, J.L., Jupp, M.L. January 2013 (has links)
No / Enhancement in productivity and cost effectiveness of high value manufacturing requires a process based management strategy. This paper introduces a Manufacturing Failure Mode Avoidance (MFMA) framework based on 4 high level process steps and underpinned by a sequence of engineering and process analysis tools to support a structured function-based decomposition of complex manufacturing processes and a continuous flow of information towards the development of robust control plans. The approach draws from experience in the automotive industry, where Failure Mode Avoidance (FMA) has been strategically adopted to achieve a step change in the effectiveness of business and engineering processes associated with the product creation processes. The paper presents a case study of the deployment of the MFMA framework to an aircraft manufacturing process followed by a broader discussion of the strength of the approach and its generic applicability to complex high value manufacturing engineering.
135

Design and Analysis of Whispering Gallery Mode Semiconductor Lasers

Hajjiah, Ali T. 27 February 2009 (has links)
Significant technical barriers currently prevent the wide spread adoption of WGM lasers as building blocks in large-scale photonic integrated circuits. The first challenge is to reduce the electrical power consumption at desirable levels of light output power. The second target is to obtain directional light emission without sacrificing other laser performance metrics. The best opportunity for success lies in the pursuit of small micro-Pillar lasers with spiral-geometry cavities. Process technology has been demonstrated for making high-performance WGM lasers including a refined ICP etching process for fabricating micro-Pillar cavities with sidewall roughness less than 10 nm and a new hydrogenation based approach to achieving current blocking that is compatible with all other processing steps and robust in comparison with earlier reports. A comprehensive photo-mask has been designed that enables investigation of the interplay between device geometry and WGM laser performance. Emphasis has been placed on enabling experiments to determining the impact of diffraction and scattering losses, current and carrier confinement, and surface recombination on electrical/optical device characteristics. In addition, a methodology has been developed for separating out process optimization work from the task of identifying the best means for directional light out-coupling. Our device fabrication methods can be proven on WGM lasers with pure cylindrical symmetry, hence results from these experiments should be independent of any specific light output coupling scheme. Particular attention has been paid to the fact that device geometries that give the best performance for purely symmetrical cavities may not yield the highest level of light emission from the spiral output notch. Such considerations seem to be missing from much of the earlier work reported in the literature. Finally, our processing techniques and device designs have resulted in individual WGM lasers that outperform those made by competitors. These devices have been incorporated into multi-element, coupled-cavity optical circuits thereby laying the groundwork for construction of digital photonic gates that execute AND, OR, and NOT logic functions. / Ph. D.
136

SUBCRITICAL CRACK GROWTH UNDER MODE I, II, AND III LOADING FOR COCONINO SANDSTONE

Ko, Tae Young January 2008 (has links)
In systems subjected to long-term loading, subcritical crack growth is the principal mechanism causing the time-dependent deformation and failure of rocks. Subcritical crack growth is environmentally-assisted crack growth, which can allow cracks to grow over a long period of time at stresses far smaller than their failure strength and at tectonic strain rates. The characteristics of subcritical crack growth can be described by a relationship between the stress intensity factor and the crack velocity. This study presents the results of studies conducted to validate the constant stress-rate test for determining subcritical crack growth parameters in Coconino sandstone, compared with the conventional testing method, the double torsion test. The results of the constant stress-rate test are in good agreement with the results of double torsion test. More importantly, the stress-rate tests can determine the parameter A with a much smaller standard deviation than the double torsion test. Thus the constant stress-rate test seems to be both a valid and preferred test method for determining the subcritical crack growth parameters in rocks. We investigated statistical aspects of the constant stress-rate test. The effects of the number of tests conducted on the subcritical crack growth parameters were examined and minimum specimen numbers were determined. The mean and standard deviation of the subcritical crack growth parameters were obtained by randomly selecting subsets from the original strength data. In addition, the distribution form of the subcritical crack growth parameters and the relation between the parameter n and A were determined. We extended the constant stress-rate test technique to modes II and III subcritical crack growth in rocks. The experimental results of the modes I, II and III tests show that the values of the subcritical crack growth parameters are similar to each other. The subcritical crack growth parameter n value for Coconino sandstone has the range of 34 to 38 and the parameter A has the range of 1.02x10⁻² to 6.52x10⁻² m/s. The effect of confining stress, specimen size, and water saturation on subcritical crack growth under mode II loading has also been investigated. Finally strength parameters for Coconino sandstone were determined experimentally, including tensile strength, uniaxial compressive strength, cohesion, internal friction angle, in-plane / our-of-plane shear strength and the fracture toughness under mode I, II, and III loading.
137

繰返しねじり荷重条件下での予き裂からのき裂進展と停留

田中, 啓介, TANAKA, Keisuke, 秋庭, 義明, AKINIWA, Yoshiaki, 御厨, 照明, MIKURIYA, Teruaki, 田中, 光一, TANAKA, Kouichi 12 1900 (has links)
No description available.
138

Experimental methods for the study of mixed-mode fractures

Eplett, Matthew R. January 2017 (has links)
Any composite material is made up from two or more materials and therefore contains interfaces, which usually represent planes of weakness. Interfacial fractures are effectively constrained to propagate along these interfaces as mixed-mode fractures with all three opening, shearing and tearing actions (i.e. mode I, mode II and mode III), instead of kinking to maintain pure-mode-I conditions at the advancing crack front, as would typically happen in an isotropic material. This is significant because mixed-mode fracture toughness is load-dependent and not a purely intrinsic material property (although clearly the pure mode fracture toughnesses are indeed intrinsic material properties that can be determined experimentally). Therefore, in order to know the fracture toughness under general loading conditions, it is necessary to know both the interface failure criterion (that describes the fracture toughness as a function of the mode mixity), and the mode mixity of the crack under the specified loading conditions. This is a complex problem that has occupied researchers in the fracture mechanics community for decades. Consequently, the literature contains a large number of different mixed-mode partition theories. This work appears to show that, of all the partition theories assessed, Wang and Harvey s (2012a) Euler beam partition theory is able to most accurately predict the fracture toughness of a mixed-mode delamination in a fibre-reinforced polymer composite laminate. This statement is based on the outcomes of three separate studies: The first study uses data reported in the literature from a thorough programme of mixed-mode fracture testing of unidirectional and multi-directional laminates. The Euler beam partition theory is able to accurately predict the fracture toughness in all cases. Furthermore, the Euler beam partition theory, which is completely analytical, closely agrees over a large domain with Davidson et al. s (2000) independently-derived non-singular field partition theory, which was derived with the aid of experimental test results. In general, the singular-field approach based on 2D elasticity and the finite element method give poor predictions. In the second study, an original programme of mixed-mode fracture testing is carried out, which incorporates several novel aspects including new test apparatus and a methodology for testing with a wide range of applied pure bending moments. Eighty five fracture tests are performed on unidirectional glass/epoxy laminates to determine the initiation and propagation fracture toughnesses. Although the second study was inconclusive with respect to the correctness of any particular partition theory, the development of the test apparatus and test methodology are considered to be major contributions that will be useful for both design engineers and academic researchers, not only working with fibre-reinforced polymer composite laminates, but also working with other composite materials containing interfacial cracks. The third study uses digital image correlation to investigate the near-crack tip strain fields of mixed-mode delaminations to try to discover the underlying mechanics that govern the selection of a mixed-mode partition theory. The new testing apparatus is used again, and another novel testing methodology is developed. The work appears to confirm (with some caveats) that two sets of pure modes exist, that is, two pure mode I modes, and two pure mode II modes, with their numerical values roughly corresponding to those from Wang and Harvey s (2012a) Euler beam partition theory. It should be noted that, as far as the author s knowledge is concerned, Euler beam partition theory is the only one in the literature to predict the existence of two sets of pure modes. Although this work set out to conclusively determine which mixed-mode partition theory is able to most accurately predict the fracture toughness of a mixed-mode delamination in a fibre-reinforced polymer composite laminate, and also, to discover why, the outcomes cannot truly be called conclusions . Rather, they only offer strong support for Wang and Harvey s (2012a) Euler beam partition theory for predicting the fracture toughness fibre-reinforced polymer composite laminates against delamination. Despite this, the work makes major contributions that will be useful for both design engineers and academic researchers in the field, as described in the above.
139

Modélisation CEM des équipements aéronautiques : aide à la qualification de l’essai BCI / EMC modeling of aeronautical equipment : support for the qualification of the BCI test

Cheaito, Hassan 06 November 2017 (has links)
L’intégration de l’électronique dans des environnements sévères d’un point de vue électromagnétique a entraîné en contrepartie l’apparition de problèmes de compatibilité électromagnétique (CEM) entre les différents systèmes. Afin d’atteindre un niveau de performance satisfaisant, des tests de sécurité et de certification sont nécessaires. Ces travaux de thèse, réalisés dans le cadre du projet SIMUCEDO (SIMUlation CEM basée sur la norme DO-160), contribuent à la modélisation du test de qualification "Bulk Current Injection" (BCI). Ce test, abordé dans la section 20 dans la norme DO-160 dédiée à l’aéronautique, est désormais obligatoire pour une très grande gamme d’équipements aéronautiques. Parmi les essais de qualification, le test BCI est l’un des plus contraignants et consommateurs du temps. Sa modélisation assure un gain de temps, et une meilleure maîtrise des paramètres qui influencent le passage des tests CEM. La modélisation du test a été décomposée en deux parties : l’équipement sous test (EST) d’une part, et la pince d’injection avec les câbles d’autre part. Dans cette thèse, seul l’EST est pris en compte. Une modélisation "boîte grise" a été proposée en associant un modèle "boîte noire" avec un modèle "extensif". Le modèle boîte noire s’appuie sur la mesure des impédances standards. Son identification se fait avec un modèle en pi. Le modèle extensif permet d’étudier plusieurs configurations de l’EST en ajustant les paramètres physiques. L’assemblage des deux modèles en un modèle boîte grise a été validé sur un convertisseur analogique-numérique (CAN). Une autre approche dénommée approche modale en fonction du mode commun (MC) et du mode différentiel (MD) a été proposée. Elle se base sur les impédances modales du système sous test. Des PCB spécifiques ont été conçus pour valider les équations développées. Une investigation est menée pour définir rigoureusement les impédances modales. Nous avons démontré qu’il y a une divergence entre deux définitions de l’impédance de MC dans la littérature. Ainsi, la conversion de mode (ou rapport Longitudinal Conversion Loss : LCL) a été quantifiée grâce à ces équations. Pour finir, le modèle a été étendu à N-entrées pour représenter un EST de complexité industrielle. Le modèle de l’EST est ensuite associé avec celui de la pince et des câbles travaux réalisés au G2ELAB. Des mesures expérimentales ont été faites pour valider le modèle complet. D’après ces mesures, le courant de MC est impacté par la mise en œuvre des câbles ainsi que celle de l’EST. Il a été montré que la connexion du blindage au plan de masse est le paramètre le plus impactant sur la distribution du courant de MC. / Electronic equipments intended to be integrated in aircrafts are subjected to normative requirements. EMC (Electromagnetic Compatibility) qualification tests became one of the mandatory requirements. This PhD thesis, carried out within the framework of the SIMUCEDO project (SIMulation CEM based on the DO-160 standard), contributes to the modeling of the Bulk Current Injection (BCI) qualification test. Concept, detailed in section 20 in the DO-160 standard, is to generate a noise current via cables using probe injection, then monitor EUT satisfactorily during test. Among the qualification tests, the BCI test is one of the most constraining and time consuming. Thus, its modeling ensures a saving of time, and a better control of the parameters which influence the success of the equipment under test. The modeling of the test was split in two parts : the equipment under test (EUT) on one hand, and the injection probe with the cables on the other hand. This thesis focuses on the EUT modeling. A "gray box" modeling was proposed by associating the "black box" model with the "extensive" model. The gray box is based on the measurement of standard impedances. Its identification is done with a "pi" model. The model, having the advantage of taking into account several configurations of the EUT, has been validated on an analog to digital converter (ADC). Another approach called modal, in function of common mode and differential mode, has been proposed. It takes into account the mode conversion when the EUT is asymmetrical. Specific PCBs were designed to validate the developed equations. An investigation was carried out to rigorously define the modal impedances, in particular the common mode (CM) impedance. We have shown that there is a discrepancy between two definitions of CM impedance in the literature. Furthermore, the mode conversion ratio (or the Longitudinal Conversion Loss : LCL) was quantified using analytical equations based on the modal approach. An N-input model has been extended to include industrial complexity. The EUT model is combined with the clamp and the cables model (made by the G2ELAB laboratory). Experimental measurements have been made to validate the combined model. According to these measurements, the CM current is influenced by the setup of the cables as well as the EUT. It has been shown that the connection of the shield to the ground plane is the most influent parameter on the CM current distribution.
140

Mode Ii Fatigue Crack Growth Behavior And Mode Ii Fracture Toughness Of 7050 Aluminum Alloy In Two Orientations

Yurtoglu, Mine Ender 01 January 2013 (has links) (PDF)
Fatigue crack growth behavior of AA7050 T7451 aluminum alloy under mode II loading condition in two orientations was investigated. Compact shear specimens were prepared in TL and LT directions. A loading frame for mode II type of loading was manufactured. Using the loading frame and the specimen, KIIC values and mode II fatigue crack growth rates were calculated. Fractographic analysis of the fracture surfaces of both mode II fracture toughness test specimens and mode II fatigue crack growth test specimens were done to examine the effects of mode II load. KIIC values were measured between 1.3 and 1.5 times the KIC values for this alloy. As for mode II fatigue crack growth rates, TL orientation shows the highest mode II fatigue crack growth resistance.

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