Pendant les dernières décennies les constructeurs automobiles ont été confrontés à la tâche difficile de réduire la consommation de carburant et les émissions de CO2. En réponse à cela, des processus d'optimisation ont été appliquées pour générer de nouvelles formes de véhicule pour réduire la traînée aérodynamique. Malheureusement, les formes optimales obtenues n’ont aucun signe distinctif pour se différentier entre les différentes marques. Les stylistes tentent aujourd'hui de redonner une signature de marque en proposant des formes «non-conventionnelles» caractérisés par des montants arrières fortement arrondis.Ce travail de thèse quantifié expérimentalement l'influence des montants arrondis sur l’aérodynamique des véhicules bi-corps (fastback). Rayonner l’arrêt entre le pavillon et la lunette du corps d’Ahmed s’avère efficace pour réduire la trainée. Ajouter un rayon de courbure sur les montants arrière latéraux ne modifie pas davantage la traînée. Cependant, l'effet net nul sur la trainée est dû à des modifications de traînée opposée.L'organisation du sillage proche et le transport de vorticité ont été analysés et relié à l'augmentation locale de la traînée. Pour augmenter encore la complexité et de la fidélité du modèle, un modèle a été réalisé en partenariat avec le département du style de PSA. La sensibilité au vent latéral a également été étudiée. Il a été montré que les montants arrières arrondis détériorent les performances en vent latéral. La compréhension des effets d'arrondi de la partie arrière des modèles de véhicule s’avère être valide malgré la complexité croissante des modèles. Enfin, des tests à l’échelle 1 on confirme les tendances observées sur les modèles à échelle réduite. / For the last decades car manufacturers have been facing the challenging task of reducing fuel consumption and CO2 emissions. In response to that, optimization processes have been applied to generate new vehicle shapes minimizing the aerodynamic drag. Since the obtained optimal shapes have no brand differentiating details, stylists are nowadays trying to give back a brand signature by proposing "non-conventional" shapes characterized by important rear pillars rounding. The present PhD work experimentally quantifies the influence of such afterbody rounding on the aerodynamic loads and on the flow field development over fastback vehicle models.Rounding the roof/backlight of the well-known Ahmed body intersection is shown to reduce drag. Surprisingly, additional rear curvature associated with side pillars rounding does not further modify the drag. However, the zero net effect is found to result from opposite drag effects. To further increase the complexity and fidelity of the model, a model is realized in partnership with the style department of PSA. Crosswind sensitivity is also investigated by means of yaw angle variation. It is shown that the rear ends with rounded edges deteriorate the lateral. The understanding of the afterbody rounding effects is shown to be valid even for increasing complexity of the models. Finally, full scale test confirms the trends observed with the scaled models.

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In this thesis, I wanted to design a lamp in collaboration with the lighting company Örsjö Belysning AB, that would contribute to stress-reduction and calmness both through visual and functional aspects. My focus in the study and the design process was on the lamps shape and light, where my primary inspiration was taken from the qualities of water. My lamp also had to fit into Örsjö Belysnings current assortment. My research showed that rounded shapes and adjustable light are two important factors for producing calmness and well-being for the user. The result of my work was a lamp with the name Harmoni. A LED floor lamp made of brass metal and acrylic plastic, with focus on rounded shapes, lightness, flexibility and symmetry. The lamp has a unique and adjustable light emission, that gives two different kinds of light from the same source. It functions both as a floor and a wall lamp in one.

A 3D Finite Element Boundary Integral technique (FE-BI) using mixed-order tangential vector finite elements (TVFE?s) is presented. This technique is used to design two wide band antennas and an ultra wideband (UWB) antenna array. Tetrahedral elements are used for domain discretization because they offer higher flexibility when simulating complex structures. A set of hierarchical mixed-order TVFE?s up to and including order 2.5 is implemented. Hierarchical mixed-order TVFE?s accurately simulate regions with high and low field variations. They also guarantee tangential field continuity across element boundaries and suppress spurious modes. The efficacy of the technique has been tested on two different wide band antennas and an UWB array. The first antenna is designed for automotive applications and covers GPS, GSM, XM, and PCS bands (0.8?3.35 GHz). The second antenna is a double sided rounded bowtie antenna (DSRBA) for UWB communication (3.1-10.6 GHz). The third design is a DSRBA array. For validation purposes, the antennas are also simulated using a commercially available high frequency electromagnetic simulation software, HFSS. Results regarding antenna parameters such as return loss, radiation pattern, and gain are also given.

This work discusses estimates based on rounded data. The work describes the estimates of parameters in time series AR and MA and in linear regression, the work presents different kinds of estimates based on rounded data. The work focuses on time series model AR(1) and linear regression, where simulations are added to theories and methods are compared on rounded and unrounded data. In addition, the comparison of linear regression is shown on the exemple of graph data. Powered by TCPDF (www.tcpdf.org)

Most recorded data are rounded to the nearest decimal place due to the precision of the recording mechanism. This rounding entails errors in estimation and measurement. In this paper, we compare the performances of three types of estimators based on rounded data from time series models, namely A-K corrected estimator, approximate MLE and the SOS estimator. In order to perform the comparison, the A-K corrected estimators for the MA(1) model are derived theoretically. To improve the efficiency of the estimation, two types of variance-reduction estimators are further proposed, which are based on linear combinations of aforementioned three estimators. Simulation results show the proposed variance reduction estimators significantly improve the estimation efficiency.

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Abstract In this thesis, a Multi-gate PD SOI Device is realized. The inverse narrow channel effect of the device is also studied. In the Multi-gate PD SOI structure, it has three-surface gate on the silicon MESA Island, which can promote the device performance. However, for eliminating the abnormal corner leakage current in the MESA Island, the process of rounded corner is used. In order to overcome the floating body effect, we use the Schottky body contact. According to the 3-D DAVINCI device simulation and the measurement results, the Multi-gate PD SOI device presents the excellent characteristics: low threshold voltage, low subthreshold factor and high breakdown voltage. In addition, comparing the Multi-gate device with that of the conventional one, the excess drain current gain is observed. In order to understand the behavior of INCE in Multi-gate PD SOI Device in depth, we use the concept of overlap depletion region to derive the expressions of threshold voltage shift. Owing to the device has rounded corner, we also study the rounded corner effect in the model formulation. Comparing calculation with that of the experiment one, the calculation shows agreement with the experiments.

Webbsystem används flitigt och även för internt bruk gäller det att vara användbar, funktionell, tydlig och ha en god navigation. Människor läser inte text utan letar efter en text som uppfyller deras mål. En undersökning på företaget Stamford AB utförs med deras interna webbapplikation som ska uppdateras och fokusen i denna rapport ligger på designval av knappar och dess läsbarhet. Användbarhetstest har utförts med hi-fi prototyper där testpersoner fick utföra olika uppgifter där flera designförslag testades för hur knappar kan se ut enligt olika designprinciper så som flat design, raised design och rounded corners. Testpersonerna ombads att tänka högt under prototyptestet och intervjuas efteråt för att samla in nödvändig data för att kunna dra slutsatser av undersökningen. Testet visade att en läsbar knapp ska ha normal eller lite mer mellanrum och ha en textstil som är normal eller fet för högsta läsbarhet. Samtliga knappar hade mouseover effekt (highlight) men ingen animation när man trycker ner knappen. Flat design ansågs vara lättare för ögonen.

This work disusses estimates based on rounded data. The work describes the estimates of parameters in time series AR and MA and in linear regression, the work presents different kinds of estimates based on rounded data. The work focuses on time series model AR(1) and linear regression, where simulations are added to theories and methods are compared on rounded and unrounded data. In adition, the comparison of linear regression is shown at graphs. Powered by TCPDF (www.tcpdf.org)