abstract: Current sensing ability is one of the most desirable features of contemporary current or voltage mode controlled DC-DC converters. Current sensing can be used for over load protection, multi-stage converter load balancing, current-mode control, multi-phase converter current-sharing, load independent control, power efficiency improvement etc. There are handful existing approaches for current sensing such as external resistor sensing, triode mode current mirroring, observer sensing, Hall-Effect sensors, transformers, DC Resistance (DCR) sensing, Gm-C filter sensing etc. However, each method has one or more issues that prevent them from being successfully applied in DC-DC converter, e.g. low accuracy, discontinuous sensing nature, high sensitivity to switching noise, high cost, requirement of known external power filter components, bulky size, etc. In this dissertation, an offset-independent inductor Built-In Self Test (BIST) architecture is proposed which is able to measure the inductor inductance and DCR. The measured DCR enables the proposed continuous, lossless, average current sensing scheme. A digital Voltage Mode Control (VMC) DC-DC buck converter with the inductor BIST and current sensing architecture is designed, fabricated, and experimentally tested. The average measurement errors for inductance, DCR and current sensing are 2.1%, 3.6%, and 1.5% respectively. For the 3.5mm by 3.5mm die area, inductor BIST and current sensing circuits including related pins only consume 5.2% of the die area. BIST mode draws 40mA current for a maximum time period of 200us upon start-up and the continuous current sensing consumes about 400uA quiescent current. This buck converter utilizes an adaptive compensator. It could update compensator internally so that the overall system has a proper loop response for large range inductance and load current. Next, a digital Average Current Mode Control (ACMC) DC-DC buck converter with the proposed average current sensing circuits is designed and tested. To reduce chip area and power consumption, a 9 bits hybrid Digital Pulse Width Modulator (DPWM) which uses a Mixed-mode DLL (MDLL) is also proposed. The DC-DC converter has a maximum of 12V input, 1-11 V output range, and a maximum of 3W output power. The maximum error of one least significant bit (LSB) delay of the proposed DPWM is less than 1%. / Dissertation/Thesis / Ph.D. Electrical Engineering 2011

Les accélérateurs sont des adjuvants couramment employés dans les matériaux cimentaires afin d’accélérer leur prise et/ou leur durcissement. Leur ajout permet d’accélérer les cadences de production de béton préfabriqué ou encore de compenser le retard d’hydratation induit par l’emploi d’ajouts minéraux cimentaires ou par des conditions hivernales. De nombreuses espèces chimiques, molécules ou ions, connues pour leur pouvoir accélérateur ont été étudiées dans la littérature. Néanmoins, souvent leur mode d’action est associé à une simple activation chimique, se caractérisant par l’accélération de l’hydratation de certaines phases cimentaires. Or au sein de la pâte cimentaire, ces adjuvants peuvent aussi avoir une action physique et modifier l’état de dispersion des grains de ciment, ce qui pourrait indirectement influencer la réactivité chimique.L’objectif de ce travail est donc d’étudier les modes d’action de différents systèmes accélérateurs en combinant l’analyse de la réactivité chimique du ciment et de l’organisation mésostructurale. Plusieurs amines de structures moléculaires différentes et plusieurs sels sodiques ont été employés seuls ou de manière combinée dans des pâtes cimentaires et des mortiers normalisés. Ces matériaux ont alors été étudiés de l’échelle nano/microscopique, puis mésoscopique à macroscopique, sur une période de temps s’étalant des premières minutes d’hydratation jusqu’à 28 jours. L’analyse du liquide interstitiel des pâtes cimentaires a permis d’évaluer les capacités de sorption et de complexation des adjuvants. Via des suivis d’hydratation par calorimétrie isotherme, diffraction des rayons X et analyse thermogravimétrique, l’impact des accélérateurs sur la dissolution des phases cimentaires anhydres et la précipitation d’hydrates a été déterminé. En parallèle, l’organisation mésostructurale des suspensions cimentaires adjuvantées a été analysée de manière directe par microscopies et granulométrie laser. Le comportement rhéologique et le suivi de sédimentation ont aussi permis d’appréhender indirectement l’état de dispersion des pâtes cimentaires. Pour finir, à l’échelle du mortier, des mesures de résistance à la compression ont été réalisées et la microstructure des échantillons a été étudiée par porosimétrie mercure et surface spécifique BET.La combinaison de ces caractérisations chimiques, physico-chimiques et granulaires a permis de mettre en évidence les principaux modes d’action des différentes familles d’accélérateurs. En particulier l’influence sur l’accélération de la structure moléculaire des amines et des espèces ioniques présentes dans le sel a été appréhendée. Enfin, l’emploi de combinaisons d’accélérateurs a permis de moduler l’accélération d’hydratation du matériau cimentaire et d’obtenir des effets synergiques. / Accelerators are common cement additives used in order to accelerate setting and/or hardening. Their addition allows accelerating production rates of precast concrete or compensating hydration retardation induced by the use of supplementary cementitious materials or by winter conditions. Several chemical species, molecules or ions, known for their accelerator power have been studied in the literature. However, their mode of action is often simply associated to chemical activation, which is characterized by hydration acceleration of particular cement phases. Yet, inside the cement paste, these additives can also have a physical action and modify the dispersion state of cement grains, which might indirectly influence chemical reactivity.Therefore the objective of this work is to study the modes of action of different accelerator systems by combining the analysis of cement chemical reactivity and mesostructural organization. Some amines with different molecular structures and some sodic salts were used individually or in a combined way in cement pastes and normalized mortars. These materials were then studied from nano/microscopic to mesoscopic and macroscopic scale over a period of time ranging from the first minutes of hydration till 28 days. The analysis of the pore solution allowed evaluating the additive sorption and complexation ability. Cement hydration was followed by isothermal calorimetry, X-ray diffraction and thermogravimetric analysis in order to determine the impact of accelerators on anhydrous cement phase dissolution and hydrate precipitation. In parallel, mesostructural organization of admixtured cement suspensions was analyzed indirectly by microscopy and laser granulometry. Rheological and sedimentation behavior also allowed apprehending indirectly the dispersion state of cement paste. Lastly, at mortar scale, compressive strength measurements were performed and sample microstructure was studied by mercury intrusion porosimetry and BET specific surface.The combination of these chemical, physicochemical and granular characterizations allowed highlighting the main modes of action of the different accelerator systems. In particular, the influence on acceleration of amine molecular structure and salt ionic species was apprehended. Finally, the use of combinations of accelerators allowed modulating the hydration acceleration of cementitious materials and obtaining synergetic effects.

O átrio esquerdo (AE) pode aumentar de tamanho e massa por sobrecarga de pressão e volume em várias doenças cardíacas, a exemplo da degeneração da valva mitral. O tamanho do AE é de especial interesse na avaliação da gravidade da doença, uma vez que o grau de aumento será um dos parâmetros para a instituição da terapia. A ecocardiografia é o método padrão para a avaliação não invasiva do paciente cardiopata e sempre inclui a mensuração do tamanho do AE. O modo-M convencional tem sido usado para tal avaliação, contudo, o mesmo tem suas limitações, devido à dificuldade em incluir a porção mais ampla do AE, resultando em um diâmetro e índice AE:AO subestimados. No modo bidimensional o AE pode ser mensurado em sua maior amplitude, resultando em uma medida mais acurada. Assim sendo, o objetivo deste estudo foi comparar os dois métodos, utilizando-se de 40 cães adultos sadios, com idade variando de 1,5 a 7 anos. No modo-M, o AE e a aorta (AO) foram medidos conforme normas da American Society of Echocardiography, no corte longitudinal para-esternal direito, e no modo bidimensional realizaram-se medidas lineares em pontos específicos e em momentos estabelecidos do ciclo cardíaco, no corte transverso para-esternal direito. Estabeleceu-se um índice para cada método, dividindo-se o diâmetro do AE com a AO. Observou-se que a diferença de diâmetro do AE no modo bidimensional (AEB) e do AE no modo-M foi estatisticamente significante (p < 0,001). O mesmo ocorreu com o índice AEB:AOB quando comparado ao índice AEM:AOM, sendo que a média do AEB:AOB = 1,379±0,130; I.C. 95%= 1,337-1,422 e a média do AEM:AOM = 1,067±0,064, I.C. 95%= 1,046-1,088. Observou-se correlação alta entre as medidas do AE, nos dois modos, com superfície de área corpórea e peso (coeficiente de correlação = 0,882-0,896). Ocorreu correlação alta também entre as medidas de AE dos sexos masculino e feminino, pelos dois métodos (p=0,003 e coeficiente de correlação = 0,725-0,732). Com relação aos índices, não houve correlação entre os mesmos e a superfície de área e o peso, podendo-se dizer que são, portanto, índices independentes de peso. O modo bidimensional oferece a possibilidade de aferição do AE em sua maior amplitude, superando assim o modo-M convencional. / The left atrium (LA) can become enlarged in size and mass attributable to both pressure and volume overload in various cardiac diseases, an example is the mitral valve degeneration. The size of LA is of special interest for clinical assessment of severity of the disease, once the degree of enlargement will be one of the parameters for therapy institution. The echocardiography is the standard method of noninvasive evaluation of the cardiac patient and often involves the LA size. The M-mode has been used to this evaluation, however it has inherent limitations, due to the difficulty in including the largest portion of the LA, underestimating the LA diameter and LA:AO index. In the two-dimensional (2D) mode, the LA can be measured at its largest portion and it is likely to be more accurate. The purpose of this study was to compare both methods, using 40 healthy adult dogs, and ages between 1,5 and 7 years old. In the M-mode, the LA and the aorta (AO) was measured according to the guidelines from the American Society of Echocardiography, using a right long-axis view and in the 2D-mode, linear measurements were made at specific time and points of the cardiac cycle, using a right short-axis view. LA:AO ratios were established for each method. The difference between the LA diameter in the 2D-mode (LAB) and in the M-mode (LAM) was significant (p < 0,001). The same has occured with the LAB:AOB index when it was compared with the LAM:AOM ratio. The LAB:AOB index was 1,379±0,130; C.I. 95%= 1,337-1,422 and the LAM:AOM index was 1,067±0,064, C.I. 95%= 1,046-1,088. It was observed high association between LA measurements, in both methods, with body weight and body surface area (correlation coefficient = 0,882-0,896) and also a high correlation between the LA in female and male, in both methods (p=0,003 e correlation coefficient = 0,725-0,732). There was no association between both indices with body weight and body surface area, which provides a body weight - independent measurement of LA size. The 2D - mode offers more accurate LA measurement , so it overcomes the M- mode.

A Na, K-ATPase (NKA) é uma proteína de membrana encontrada em organismos eucariotos multicelulares cuja atividade e funções já são amplamente discutidas na literatura. Sua unidade funcional corresponde a um heterodímero formado por duas subunidades , com regiões transmembrana. Espécies multiméricas como dímeros e tetrâmeros dessa enzima também são conhecidos por exercer atividade enzimática. As interações lipídio-proteína são intrínsecas para a NKA, por tal motivo, proteolipossomos constituídos de DPPC e DPPC:DPPE foram preparados por co-solubilização. Como controle, lipossomos de mesma composição foram produzidos por extrusão e/ou sonicação. Para as imagens de AFM, as amostras foram fixadas com glutaraldeído, para proteção mecânica e contra desidratação das vesículas. Para lipossomos de DPPC as imagens topográficas de AFM das vesículas apresentaram formato oval, superfície perfeitamente lisa e diâmetro médio de 151 + 46 nm, enquanto as vesículas de composição DPPC:DPPE, apesar de lisas, tiveram cantos pontiagudos e diâmetro médio de 98 + 28 nm. Imagens de fase de ambas as composições não apresentaram qualquer indicativo de diferenças na composição química, provavelmente devido à natureza de carga neutra dos dois fosfolipídios. As imagens de fase por AFM para os proteolipossomos tanto de DPPC-NKA, quanto DPPC:DPPE-NKA, revelaram resultados inéditos na literatura, onde a inserção da NKA aparece como nítidas regiões transições de fase de composição química distinta quando comparadas com os lipossomos. No entanto, as mudanças de fase são diferentes entre as composições estudadas, aparecendo como manchas escuras circulares para DPPC-NKA e mais visíveis como interstícios brilhantes para composição de DPPC:DPPE-NKA. As vesículas de DPPC-NKA apresentaram diâmetro médio de 390 + 326 nm e, nas imagens de topografia tridimensionais, protusões de 38 a 115 nm correspondentes às regiões de mudanças de fase, que, indicaram o diâmetro dos microdomínios relacionados à proteína. Já nas imagens para DPPC:DPPE-NKA o diâmetro médio dos proteolipossomos foi de 189 + 156 nm, e as protusões apareceram entre os interstícios, variando de 20 a 66 nm. O estudo de DSC dos lipossomos revelou que a concentração de glutaraldeído nas condições das análises de AFM, em torno de 5% (v/v), afetam as características físico-químicas para as composições com DPPE. A AFM foi eficiente para confirmar a reinserção da NKA em proteolipossomos pelas imagens de fase, e, para medir o diâmetro dos microdomínios pelas imagens de topografia. / Na, K-ATPase (NKA) is a membrane protein present in eukaryotic multicellular organisms. Its functions and activity are already widely described in the literature. Its minimal functional structure is a heterodimer of two main subunits , with transmembrane domains. However, dimers and tetramers of the enzyme are also known to have enzymatic activity. Since there are intrinsic lipid-protein interactions, NKA proteoliposomes composed of DPPC and DPPC:DPPE (1:1 molar ratio) were prepared by the co-solubilization method and liposomes of the same compositions were obtained by extrusion and/or sonication to be used as control. The samples to the AFM study were prepared using glutaraldehyde to protect the vesicles from mechanical shocks and dehydration. Liposomes composed of DPPC and DPPC:DPPE (1:1 molar ratio) were prepared by extrusion and sonication, respectively, as control. The topographical images for DPPC liposomes showed vesicles with an oval shape and smoothed surfaces with a mean diameter of 151 + 46 nm. DPPC:DPPE vesicles also presented smoothed surfaces, but with pointed corners and mean diameter of 98 + 28 nm. Phase images for both lipid compositions showed no differences in chemical composition. For DPPC:DPPE samples, this can be explained by the neutral net charge of both lipids. The proteoliposomes observed in the AFM phase images showed darker and large circular spots in the vesicles. These spots represent delays in the phase oscillation of the AFM probe and are associated with different chemical composition. The phase changes showed the reconstitution of the NKA in the proteoliposomes. When compared with topographical images, this spots matched protrusions. The mean diameter of DPPC-NKA proteoliposomes determined by AFM was 390 + 326 nm. In the three-dimensional topographical images of composition, protrusions from 38 to 115 nm near the areas of different phases indicate the diameters of the NKA microdomains. The phase changes for DPPC:DPPE-NKA appeared as bright interstices with the protrusions of the topographical images in between them. The size of these protrusions ranged from 20 to 66 nm and the mean diameter of the proteoliposomes was 189 + 156 nm. The DSC liposomes data showed that the glutaraldehyde concentration used in the AFM analysis affect the physical chemistry properties of the samples with DPPE. AFM proved to be an efficient method to confirm the reconstitution of into proteoliposomes with phase images and to determine the diameter of the protein microdomains with the topographical images.

Gamer mode är ett vinstfokuserat-beteende där Frank menar att det finns 3 faktorer till varför ”gamer mode” uppkommer, där en av faktorerna handlar om hur spelet framställs. I det här arbetet har fokus varit på den andra faktorn om framställning och hur den påverkar spelarens beteende gällande poängsamlande. Deltagarna i undersökningen delades upp i två grupper och som skulle spela ett spel som var identiskt förutom dess framställning i form utav en introduktionsskärm. Denna introduktionsskärm uppmanade till att utföra egocentriska eller altruistiska uppgifter där de egocentriska uppgifterna lede till poäng. Resultatet visade på att den gruppen som fick en egocentrisk framställning var mer benägna till poäng medan de som fick en altruistisk framställning inte var lika benägna till poängsamlande. Möjligheter till vidare forskning finns genom att pröva olika grader av framställning för spelaren för att undersöka hur dess beteende påverkas, samt liknande undersökning fast i ett 3D-spel.

Context. Cloud computing (CC) is developed as a Human-centered computing model to facilitate its users to access resources anywhere on the globe. The resources can be shared among any cloud user which mainly questions the security in cloud computing. There are Denial of Service and Distributed Denial of Service attacks which are generated by the attackers to challenge the security of CC. The Next-Generation Intrusion Prevention Systems (sometimes referred as Non-Traditional Intrusion Prevention Systems (NGIPS) are being used as a measure to protect users against these attacks. This research is concerned with the NGIPS techniques that are implemented in the cloud computing environment and their evaluation. Objectives. In this study, the main objective is to investigate the existing techniques of the NGIPS that can be deployed in the cloud environment and to provide an empirical comparison of source mode and destination mode in Snort IPS technique based on the metrics used for evaluation of the IPS systems. Methods. In this study, a systematic literature review is used to identify the existing NGIPS techniques. The library databases used to search the literature are Inspec, IEEE Xplore, ACM Digital Library, Wiley, Scopus and Google scholar. The articles are selected based on an inclusion and exclusion criteria. The experiment is selected as a research method for the empirical comparison of Source mode and destination mode of Snort NGIPS found through literature review. The testbed is designed and implemented with the Snort filter techniques deployed in the virtual machine. Results. Snort is one of the mostly used NGIPS against DoS and DDoS attacks in the cloud environment. Some common metrics used for evaluating the NGIPS techniques are CPU load, Memory usage, bandwidth availability, throughput, true positive rate, false positive rate, true negative rate, false negative rate, and accuracy. From the experiment, it was found that Destination mode performs better than source mode in Snort. When compared with the CPU load, Bandwidth, Latency, Memory Utilization and rate of packet loss metrics. Conclusions. It was concluded that many NGIPS of the cloud computing model are related to each other and use similar techniques to prevent the DoS and DDoS attacks. The author also concludes that using of source based and destination based intrusion detection modes in Snort has some difference in the performance measures.

La question de savoir si la relation est différente réellement de son fondement se rencontre fréquemment dans les textes médiévaux à partir du milieu du treizième siècle. Elle se pose avant tout dans un cadre aristotélicien de discussion des catégories et revient à se demander si la catégorie de relation ajoute véritablement une chose supplémentaire, la relation, dans la réalité. Cette question s'inscrit dans une représentation réaliste des relations : pour la plupart des auteurs du treizième et du quatorzième siècle, le fait que des choses soient réellement reliées entre elles ne fait pas de doute. Deux hommes de même taille sont bel et bien égaux, c'est-à-dire réellement reliés entre eux par une relation d'égalité. La difficulté est alors de comprendre comment ces choses sont reliées entre elles, ou encore, ce qu'est exactement cette relation dont il est alors question. Faut-il dire que l'égalité dans chacun des hommes de même taille est une nouvelle chose qui s'ajoute à la substance de chacun d'eux et aux accidents de taille, appartenant à la catégorie de quantité, sur lesquels ces relations d'égalité sont fondées ? Ou faut-il dire que l'égalité est réelle d'une autre manière, c'est-à-dire sans pour autant ajouter une nouvelle chose à ce à quoi elle advient ? Ce problème, qui se rencontre déjà dans les tensions existant entre les différents exposés qu'Aristote a consacrés à cette catégorie, a reçu de multiples réponses. Celles-ci nous éclairent sur la manière dont le réel est appréhendé au Moyen-Âge et sur les débats ontologiques de l'époque. Le travail ici résumé entreprend de délimiter précisément ces réponses et propose une manière de les classer. / Whether relation is really distinct from its foundation or not is a question that can easily be found in medieval texts from the mid-thirteenth century onwards. It comes from an aristotelian background, the discussion about the categories, and asks if the category of relation really posits another thing, i.e. a relation, in reality. It results from a realist perspective on relations. In fact, most thirteenth and fourteenth century thinkers held without doubt that things outside the mind are really connected between them. Two men sharing the same height are really equal, that is, really linked to each other by a relation of equality. What is then left to understand is how these things are linked between them, or the exact nature of the aforementioned relation. Should we say that the equality in each of the equally sized men is a new thing that adds to the substance of each of them and to the accidents of height, belonging tho the category of quantity, on which these relations are founded? Or should we say that equality is real in another way, that is, without adding a new thing to the subject acquiring it? We can already find this issue in Aristotle himself, emerging from disagreeing texts devoted to this category. It received various answers that enable us to understand better how reality was defined in the Middle Age and some of the ontological debates of the time. The work that is here summed up attempts to precisely delineate these various answers and to provide a way of classifying them.

Ce travail de thèse porte sur le couplage d’émetteurs fluorescents (en l’occurrence des nanostructures semi-conductrices colloïdales) à leur environnement optique. Il se décompose en deux parties : dans la première, des structures photoniques (modes de Tamm optiques) sont caractérisées par le biais de la fluorescence de nanocristaux insérés dans ces structures. Dans la seconde, des nanoplaquettes individuelles de CdSe/CdS sont caractérisées par des études de microphotoluminescence sur différents types de substrats. Dans ces deux études, la mesure du diagramme de rayonnement par imagerie dans le plan de Fourier joue un rôle important, et son principe sera présenté en détail. Le mode optique de Tamm est un mode électromagnétique confiné entre un miroir de Bragg et une couche métallique. Nous avons couplé une couche de nanocristaux de CdSe/CdS avec des modes de Tamm optiques 2D et 0D. Le confinement latéral dans le cas du mode 0D est mis en évidence. Nous avons étudié la relation de dispersion de l’émission issue de différentes portions du disque et comparé ces résultats avec les simulations numériques. Enfin, en excitant différentes position sur le disque, nous avons montré que la direction d’émission dépend fortement de la position de la source au sein de la structure. D’autre part, nous avons mis en place une méthode fine pour déterminer la nature dipolaire (dipôle 1D ou 2D) et l’orientation d’un nano-émetteur individuel. L’idée principale est de mesurer à la fois, pour un seul émetteur, le diagramme de rayonnement et la polarisation d’émission. En choisissant un substrat adapté (de l’or ou du verre), ces mesures donnent des résultats théoriques très différents selon la nature et l’orientation du dipôle. Nous avons ensuite appliqué cette méthode sur les émetteurs nanoplaquettes de CdSe/CdS (dimensions 20x20x2 nm). Un accord parfait entre les mesures et les calculs analytiques nous confirme que l’émission d’une plaquette carrée peut être décrite par un dipôle 2D orienté dans le plan de la plaquette. Nous avons ensuite étudié l’émission d’une plaquette rectangulaire et montré une asymétrie dans le dipôle émetteur. Cette étude montre le rôle de la forme de la plaquette sur son dipôle d’émission, qui pourrait être expliqué par un effet d’antenne diélectrique. / Technological progress in the recent 30 years for reducing the size of semi-conductor materials offers the possibility to fabricate devices in which the electrons and holes are confined in a very small volume in three dimensions. When the dimension of the material is small (a few nanometers), the charges experience quantum confinement effects. This kind of nanomaterial is called nanocrystal or quantum dot [1]. These structures have the remarkable property that the energy levels are discretized, in a sense making them artificial atoms. At the beginning of 1980s, Efros, Ekimov et al. started the growth of II/VI semi-conductor nanocrystals in a vitreous matrix [2]. A few years later, colloidal synthesis methods were developed and nanocrystals with increasingly good optical properties were obtained [3-5]. These emitters have drawn intense attention because of their versatile manipulation in solution and biochemical functionalization, high quantum effciency, and photostability, tunable emission wavelength and broad absorption spectrum. By fluorescence microscopy, it is possible to study the optical properties of individual nanocrystals ; non classical effects such as single photon emission (even for nanocrystals at room temperature) are evidenced. Studying individual nano-emitters offers new ways to test the concepts of electromagnetics in the visible domain. Other manipulations are possible by nano structuring the environment around an emitter ; for instance, the use of antennas, which is ubiquitous in the radio and microwave domains, can be extended to nano-photonics, provided that sufficiently precise nano-fabrication techniques are available. The group "Nanophotonics and quantum optics" at the Institut de NanoSciences de Paris (INSP) studies how to manipulate light by coupling fluorescent emitters (individually or collectively) with their optical environment. The emission properties of nanoemitters depend strongly on their optical environment. This is expressed, as for the decay time of a radiating dipole, by Fermi's golden rule: where the initial and final state of the nanoemitter transition are taken into consideration; the polarization of these states can infuence highly the emission properties (determined by the symmetries of the transition and its associated orientation). The local state density which is mainly determined by the optical environment around the emitter and depends on the emission angular frequency. The electric field at the emitter position is included in the Hamiltonian (for a dipolar electric transition). Previously, our team has studied the coupling between the nanocrystal and different nanophotonic structures such as photonic crystals, plasmonic structures, plasmonic patch antennas etc...

Området för denna studie är att studera kommunikation mellan företag och kunder. I studien har ett “fast fashion” företag används som exponent. Studien avgränsas till unga kvinnor 15-30 år då företaget har detta kundsegment som målgrupp.  Kommunikation är idag ett viktigt verktyg för företag att sända ut budskap. Den digitala utvecklingen kräver att företag använder digitala medier för att behålla och generera nya kunder. Syftet med denna studie är att undersöka hur kommunikativa instrument kan påverka och optimera företagets specifika kundsegment. I studien analyseras hur budskapet når fram och hur den utsända signalen uppfattas, samt vilka strategier som används för att behålla kundsegmentet i takt med att detta ständigt utvecklas. Schramms kommunikationsmodell har använts som hjälpmedel och visar att signalen från konsument till företag är minst lika viktig som tvärtom. Målet med studien är att få svar genom att besvara tre utvalda forskningsfrågor; Hur uppfattas företagets kommunikativa instrument utav den specifika kundsegment? Hur gör företaget för att behålla sitt kundsegment? Hur kan de kommunikativa instrumenten förbättras i relation till kundsegmentets preferenser? Frågeställningarna besvaras med hjälp av insamlat empiriskt material där intervjuer, enkätundersökning samt passivt deltagande observationer har förts. Genom det framgår resultatet att det är viktigt att exponenten sänder ut signalen till rätt kundsegment. Slutsatsen är att konsten att behålla sitt kundsegment i den snabba förändringen inom “fast fashion”, är att ha kommunikation som den viktigaste pelaren och att veta till vilka den ska riktas mot.

Face aux défis actuels posés par la pollution atmosphérique et la congestion des axes routiers urbains et périurbains et à l’étalement urbain, les pôles d'échanges multimodaux (PEM) sont conçus et mis en œuvre comme des outils de développement de mobilités durables, susceptibles de favoriser l’utilisation de modes de transport complémentaires (marche à pied, vélo, autobus urbains, tramways, métros…).Leur présence de plus en plus affirmée le long des axes de transports collectifs en site propre (TCSP) démontre leur adaptabilité aux différents contextes institutionnels, territoriaux et réticulaires. Leur but est de limiter le trafic automobile entrant dans les villes, et de susciter un report modal suffisant vers les transports collectifs. Cela donne lieu à des études très poussées en matière d’estimation des flux et d’insertion urbaine. Car les PEM entretiennent des relations avec les quartiers où ils sont implantés.Mais cette profusion des PEM, que l'on observe depuis une trentaine d'années - avec une accélération au début des années 2000 - cache en réalité des réalités bien différentes, tout comme les appellations que les AOTU leur donnent. En dépit de tentatives de normalisation, faites par les pouvoirs publics, nous constatons que le fonctionnement des PEM et leur configuration physique répondent avant tout aux nécessités locales et aux compromis entre les différents acteurs impliqués dans la construction et l’exploitation de ce type d’équipements.Notre thèse se propose donc de dresser un état des lieux de la recherche en matière de PEM et d'intermodalité, en ayant recours à de nombreux outils et méthodes (relevés et enquêtes de terrain, entretiens avec des professionnels acteurs du secteur des transports publics, démarche modélisatrice et d’inventaire des services proposés) pour déterminer si le PEM est bien un élément majeur des politiques de transport public et s'il contribue pleinement, en son sein, à l'interfaçage d'échelles de transports complémentaires. / Confront the challenges posed by air pollution and congestion on urban and suburban roads and urban sprawl, the multimodal hubs are designed and implemented as a sustainable mobility development tools, which may promote the use of complementary modes of transport (walking, cycling, transit buses, trams, subways ...).Their presence increasingly assertive along public transport axes own site demonstrates their adaptability to different institutional contexts, territorial and reticular. Their goal is to limit car traffic entering the cities, and generate sufficient modal shift towards public transport. This gives rise to very extensive studies in estimating flow and urban integration. Indeed, multimodal hubs have relations with the neighborhoods where they are located.But this profusion of multimodal hubs, which is observed over the past thirty years - with an acceleration in the early 2000’s - actually hides realities very different, as are the names that give them local transport authorities. Despite standardization attempts made by the government, we find that the operation of multimodal hubs and their physical configuration leads to meet local needs and compromise between the different actors involved in the construction and operation of this type of equipment.Our thesis therefore proposes to draw up an inventory of research for multimodal hubs and intermodality, by using many tools and methods (surveys and field surveys, interviews with professionals involved in public transport sector, model-process and inventory of available services) to determine whether the multimodal hub is a major element of public transport policies and if it contributes, within it, interfacing complementary scales transport.