Dynamic monitoring of structures is a method of detecting changes and damage to the structure. Vibration based monitoring has been used to detect damage in rotating machinery and is gaining popularity in the field of Structural Health Monitoring (SHM). Monitoring involves detecting changes in natural frequencies and changes in mode shapes. These changes reflect changes to properties of the bridge which can indicate damage. The Nibley Bridge is a single span bridge comprised of ten deck bulb girders. The bridge spans 25.91m (85 ft.) and includes two lanes, sidewalks on both sides, and a small median. The Nibley Bridge was constructed with monitoring in mind. A dynamic monitoring system was planned to detect frequencies for long term monitoring. Initial monitoring of the embedded accelerometers was ineffective, so additional testing was required. An impact test was done with additional sensors to calibrate the embedded sensors. To further define the natural frequencies and mode shapes of the bridge, two shaker tests were also performed. The embedded sensors were noted as having a large noise range. Also, they required a specific data logger to detect meaningful data. Recommendations for the use of the embedded accelerometers were determined and defined. The additional tests were able to assist in calibrating the accelerometers, as well as defining the natural frequencies and mode shapes of the structure. Natural frequencies were defined for each test and the changing condition of the bridge between those tests. The addition of asphalt occurred between two tests and a change of approximately 20° C between the other two tests. Though there is not much information to form a correlation, the detected changes define the dynamic aspects of the bridge. Lastly, mode shapes were determined and a Modal Assurance Criterion (MAC)analysis was done to correlate the measured and analytical mode shapes. This model helped to indicate which parameters effect the mode shapes of the structure. Comparison between these parameters and changes between them help to indicate the predicted behavior of the structure under different circumstances. Though these tests do not define all of the dynamic properties of the bridge, they do provide a general baseline of values that can be expected for future tests of the structure.

This work is devoted to the theoretical and numerical aspects of shape optimization. The first part (chapter I to IV) deals with optimization problems under convexity constraint or constant width constraint. We give several new results related to Newton's problem and Meissner's conjecture. The second part (chapter V to VII) deals with the numerical study of shape optimization problems where many shapes or phases are involved. Some new numerical methods are introduced to study optimal configurations of famous problems : Kelvin's problem and Caffarelli's conjecture. The last part (chapter VIII and IX) is devoted to optimal transportation problems and irrigation problems. More precisely, we introduce a general framework, where different kind of cost functions are allowed. This seems relevant in some problems presenting congestion effects as for instance traffic on a highway, crowds moving in domains with obstacles. In the last chapter we give preliminary results related to the numerical approximation of optimal irrigation networks.

<p>Att ta fram en ny bilmodell är ett tidskrävande och omfattande arbete där många olika kunskapsområden måste samspela. En del i utvecklingsprocessen som får allt större betydelse är designarbetet. Om bilens utförande och design inte tilltalar konsumenterna innebär detta låga försäljningssiffror och därmed förlorade intäkter för företaget.</p><p>Det huvudsakliga syftet med detta arbete är att grundligt undersöka om och hur CAD-programmet Catia V5 med modulen Imagine & Shape (IMA) skulle kunna användas på Volvo Car Corporations designavdelning (PVS). Syftet är också att granska vad en implementering av Catia V5 med IMA-modulen skulle innebära för produktutvecklingsprocessen, samt att undersöka vilka som skulle kunna använda sig av programmet. </p><p>För att undersöka hur Catia V5:s IMA-modul skulle kunna fungera på PVS har vi i samarbete med designstuderande Pontus Ny modellerat en konceptbil, komplett med exteriör, instrumentpanel, mittkonsol, ratt, stolar, baksäte, fälgar och hjul. Vi har även modellerat en växelspak och en backspegel som först har tagits fram i Alias, vilket har möjliggjort en jämförelse mellan Alias och Catia V5:s IMA-modul. Modellerna har sedan utvärderats genom enkäter med uppföljande intervjuer. Urvalsguppen utgörs av ett antal anställda hos PVS som har haft möjlighet att sätta sig in i IMA-modulen. </p><p>Respondenterna uppgav fördelar som anmärkningsvärd snabbhet vid framtagning av 3D-modeller i de fall där ytan inte behöver vara perfekt. Dock krävs stor erfarenhet för att skapa en bra renhet och ytjämnhet vid stora ytor. Samtliga involverade i detta projekt anser också att Catia V5 med IMA-modulen skulle kunna fungera som ett konceptgenereringsverktyg i ett tidigt skede. Att använda IMA-modulen i den första förberedande fasen skulle enligt vår mening innebära tidsbesparingar, eftersom användaren snabbt kan genomföra förändringar på en modell redan på möten. I dagsläget måste en Alias-modellör samla in alla ändringar, genomföra dessa snabbast möjligt och därefter bestämma en tid för ett nytt möte då alla inblandade kan närvara, vilket sällan är enkelt. </p><p>IMA-modulen skulle även kunna vara ett bra hjälpmedel för en designer, som själv kan modellera sina idéer och därigenom lättare åskådliggöra och diskutera sitt koncept vid möten. I många fall är det enklare att förstå en 3D-modell som man kan vrida och vända på, än en ritning på ett papper. Utifrån IMA-modellen skulle det vara möjligt att fräsa ut en lermodell, vilken kan finjusteras och sedan åter scannas in och bearbetas vidare i Alias.</p>

A method has been developed to measure the perceived depth of computer generated images of simple solid objects. Computer graphic techniques allow for independent control of different depth queues (stereo, shading, and texture) and enable the investigator thereby to study psychophysically the interaction of modules for depth perception. Accumulation of information from shading and stereo and vetoing of depth from shading by edge information have been found. Cooperativity and other types of interactions are discussed. If intensity edges are missing, as in a smooth-shaded surface, the image intensities themselves could be used for stereo matching. The results are compared with computer vision algorithms for both single modules and their integration for 3D vision.

This paper presents an image-based rendering system using algebraic relations between different views of an object. The system uses pictures of an object taken from known positions. Given three such images it can generate "virtual'' ones as the object would look from any position near the ones that the two input images were taken from. The extrapolation from the example images can be up to about 60 degrees of rotation. The system is based on the trilinear constraints that bind any three view so fan object. As a side result, we propose two new methods for camera calibration. We developed and used one of them. We implemented the system and tested it on real images of objects and faces. We also show experimentally that even when only two images taken from unknown positions are given, the system can be used to render the object from other view points as long as we have a good estimate of the internal parameters of the camera used and we are able to find good correspondence between the example images. In addition, we present the relation between these algebraic constraints and a factorization method for shape and motion estimation. As a result we propose a method for motion estimation in the special case of orthographic projection.

The development of a leading edge propeller blade reconfiguration system using Shape Memory Allow (SMA) muscles is presented. This work describes the design and testing of a leading edge flap, which is used to alter the local camber of a propeller blade. The leading edge flap is deflected by SMA wires housed in the blade and maintained in a fixed position with a shaft locking and releasing mechanism. A locking and releasing mechanism is utilized so that constant actuation of the SMAs is not required to maintain leading edge deflection. The profile at 70% span of the propeller blade was used to create a two-dimensional blade for leading edge flap design implementation and load testing. Deflection of up to five degrees was obtained with the final design of the leading edge flap and locking and releasing mechanism. The SMA muscles used to deflect the leading edge were actuated electronically through resistive heating and were controlled by a proportional/integral gain control algorithm with closed-loop feedback from a linear displacement sensor within the blade. With the final design of the leading edge flap and locking and releasing mechanism, a preliminary design for a three-dimensional propeller was created.

For natural gas combustion, there is a large amount of experience in the gas turbine industry. However, much of the design work is based on costly combustion tests due to insufficient accuracy of existing prediction tools for data such as emissions and effects due to fuel composition. In the present work, Computational Fluid Dynamics (CFD) approach is used to study partially premixed combustion in the 3rd generation DLE (Dry Low Emission) burner that is used in SGT-700 and SGT-800 gas turbines. The fuels that are studied here are natural gas and enriched hydrogen fuel. The CFD models which are used in this work are an axisymmetric and a 3D model and the softwares are ANSYS CFX and ANSYS FLUENT. One of the main objectives of this thesis is the study of flame shape and NOx emission in hydrogen enriched combustion. In the first study of the present work, effect of adding hydrogen to non-preheated gas combustion was investigated and the results were compared with the available measurement data. Calculated laminar burning velocity with CANTERA showed a good agreement with the experimental and numerical references. Also, the accuracy of generated flamelet libraries in CFD tools to calculate adiabatic flame temperature was compared with different available tools. Results showed good agreement between available tools for the ranges of interest. In addition, flame shape and NOx prediction was studied in the gas turbine burner. Adding hydrogen to the fuel increased significantly turbulent burning velocity and OH distribution in the domain. The effect of hydrogen on the central stagnation point was studied and the simulation results did not show a significant effect on the stagnation point location. Beside the flame shape, this study showed that although the CFD NOx prediction tools in ANSYS CFX and ANSYS FLUENT predict the trend of NOx and the flame propagation in the right manner, in order to use as a reliable prediction tool in the gas turbine industry they need to be improved.

This thesis presents experimental results of shape’s influence on user’s performance in terms of time and accuracy in shape replication task. The shapes are drawn with mouse, pen and touch input devices. For this purpose, two non-meaningful, semi- randomly generated shapes have been used. The first shape has a combination of straight lines and curves whereas the second shape has curves only. Each of these shapes is presented in four versions namely contour, polygon, narrow tunnel and wide tunnel. A method to compare versions of these shapes with the corresponding versions of user drawn shapes is presented. In general, the results showed that the replication of second shape takes less time and the replicated shape is more accurate when compared to the first shape. In addition, performance of the input devices was found to be dependent upon the shapes and their versions they were used to draw.

The problem of shape control of composite laminated smart structures with piezoelectric patches placed at optimal location is considered in this thesis. Laminated plate structures with piezoelectric patches for shape control applications are modeled using a shear deformable plate formulation by including the piezoelectric layers into the plate substrate. A composite plate finite element model is also developed for composite plates with self-sensing actuators. Non-linear hysteresis models for piezoelectric materials are presented and discussed. Numerical simulation of composite plate structures with piezoelectric actuators is conducted and presented. The optimization problem of finding the optimal location of actuators using a linear quadratic control algorithm is done and the results are discussed. Static shape control strategies are also discussed.

Flicker defined form (FDF) is a temporally-dependent illusion created by the counterphase flicker of randomly positioned element dots, that preferentially stimulates the magnocellular system. Previous studies have found improvement with peripheral presentation, a resistance to blur and a dependence on high temporal frequencies. (Quaid & Flanagan, 2005a; Quaid & Flanagan, 2005b). Although it is seemingly very different from most luminance defined, static stimuli, it is still unknown in what ways it differs. The current study aimed to determine how FDF varies or is similar to static, luminance defined stimuli. Current results showed that FDF could be matched to particular spatial frequencies, and improved with increasing background structure and area. Shapes could be discriminated from each other and recognized. These results suggest that although FDF is dependent on motion pathways for temporal dynamic perception, it could also benefit from the input of form perception pathways, depending on the cues present in the stimulus (e.g. background structure, area). Results also showed that FDF does not benefit from Gestalt rules of contour closure, unlike some static stimuli, although related studies have shown that FDF could still be detected in spite of blur. These studies suggest that FDF appears to rely on motion perception pathways, areas such as MT, but is easier to perceive at times due to overlap in function with shape perception pathways, areas such as IT. As such FDF shares many characteristics with other motion-defined-form stimuli, but uniquely shares aspects of form vision.