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American college football features an enormous amount of music woven into the fabric of the event, with selections accompanying approximately two-thirds of a game’s plays. Musical selections are controlled by a number of forces, including audio and video technicians, university marketing departments, financial sponsors, and wind bands. These blend together in a complex design that offers audible and visual stimulation to the audience during the game’s pauses. The music chosen for performance in these moments frequently communicates meaning beyond entertainment value. Selections reinforce the game’s emotional drive, cue celebrations, direct specific audience actions, and prompt behaviors that can directly impact the game. Beyond this, music is performed to buttress the successes of the home team, and to downplay its failures. As this process develops over the course of the game, the musical selections construct a sonic narrative that comments on the game’s action, enhancing or suppressing audience members’ emotional reactions to the events on-field, and informing their understanding of the game’s developments. By preparing for and responding to in-game situations, music creates a coherent narrative out of football’s unpredictable events. This project demonstrates the use of musical narrative in American college football via close consideration of case studies of games representing five of the most prominent college athletic conferences, the Atlantic Coast Conference, the Big 10, the Big 12, the Pac 12, and the Southeastern Conference. These sources include interviews with college football’s musical agents, including sound operators, band directors, and producers, as well as documentation of the games’ on-field developments and the music that accompanies them. Finally, this project utilizes of musical narrative as a new means of critically considering the power lines of race and gender in college football culture.

Background. Being able to modify virtual environments can create immersive experiences for video-game players. Storing data as volumetric scalar fields allows for highly modifiable 3D environments that can be converted into GPU-friendly triangles with isosurface algorithms. Using scalar fields and isosurface algorithms can be more computationally expensive and require more data than the more commonly used polygonal models. Objectives. The aim of this thesis is to explore solutions to modifying real-time 3D environments with isosurface algorithms. This will be done in two parts. First in terms of observing how modern games deal with storing scalar fields, researching which isosurface algorithms are being used and how they are being used in games. The second part is to create an application and limit the data storage required while still running at a real-time speed. Methods. There are two methods to achieve the aim. The first is to research and see which data structures and isosurface algorithms are being used in modern games and how they are utilized. The second method will be done by implementation. The implementation will use the GPU through compute shaders and use marching cubes as isosurface algorithm. It will utilize Christopher Dyken’s Histogram Pyramids for stream compaction. Two different versions will be implemented that differ in terms of what data types will be used for storage. The first using the data type char and the second int. Between these two versions, the runtime speed will be measured and compared on two different hardware configurations. Results. Finding good data on what algorithms games use is difficult. Modern games are using scalar fields in many different ways: Some allow almost complete modification of terrain, others only use it for a 3D environment. For data storage, octrees and chunks are two common ways to store the fields. Dual Contouring appears to be the primary isosurface algorithm being used based on the researched games. The results of the implementation were very fast and usable in real time environments for destruction of terrain on a large scale. The less storage intensive variation of this implementation(char) gave faster results on modern hardware but the opposite(int) was true on older hardware. Conclusions. Modifying scalar field terrain is done at a very large scale in modern games. The choice of using Dual Contouring or Marching Cubes depends on the use-case. For areas where sharp features can be important Dual Contouring is the preferred choice. Likely for these reasons Dual Contouring was found to be a popular choice in the studied games. For other areas, like many types of terrain, Marching Cubes is very fast, as can be seen in the implementation. By using the char version of the implementation, interacting with the environment in real-time is possible at high frame-rates.

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Three papers are presented, applying computational fluid dynamics methods to fluid flows in the geosciences. In the first paper, a numerical method is developed for single phase potential flow in the subsurface. For a class of monotonically advancing flows, the method provides a computational savings as compared to classical methods and can be applied to problems such as forced groundwater recharge. The second paper investigates the shear stress reducing action of an erosion control roughness array. Incompressible Naiver-Stokes simulations are performed for multiple wind angles to understand the changing aerodynamics of individual and grouped roughness elements. In the third paper, a 1D analytical flow model is compared with multiphase Navier-Stokes simulations in a parabolic fissure. Sampling the numerical results allows the isolation of flow factors such as surface tension, which are difficult to measure in physical experiments.

Le monde médical dispose de plus en plus de sources d'images différentes, non seulement pour réaliser un diagnostic mais aussi pour évaluer l'efficacité d'un traitement et pour être guidé dans les interventions chirurgicales. Parallèlement, le développement des techniques opératoires s'oriente vers la chirurgie non " à ciel ouvert ", notamment la coelioscopie, qui permet de diminuer les risques liés à l'intervention ainsi que le temps d'hospitalisation du patient. En revanche, elle rend moins intuitive la réalisation de l'acte chirurgical, notamment du fait de la vision réduite à l'utilisation d'une ou plusieurs caméras dans la région d'intérêt. Durant ma thèse, j'ai conçu et mis en oeuvre des nouvelles méthodes informatiques de traitement 3D d'images radiologiques ainsi que de nouvelles utilisations médicales de ces images. Les contributions présentées concernent la visualisation et le traitement des données, la segmentation de structures 3D, la fusion mono et multimodale et l'aide à la réalisation d'interventions. Les applications présentées concernent notamment la planification et la réalisation d'interventions sous coelioscopie et de ponctions mais aussi l'imagerie industrielle. L'utilisation conjointe de différentes modalités d'images permet d'améliorer la visualisation, la manipulation et la compréhension de scènes tridimensionnelles, conduisant à une plus grande compréhension des observations et à une meilleure prise de décision.

<p>Wave scattering is the phenomenon in which a wave field interacts with physical objects. An incoming wave is scattered at the surface of the object and a scattered wave is produced. Common practical cases are acoustic, electromagnetic and elastic wave scattering. The numerical simulation of the scattering process is important, for example, in noise control, antenna design, prediction of radar cross sections and nondestructive testing.</p><p>Important classes of numerical methods for accurate simulation of scattering are based on integral representations of the wave fields and theses representations require the knowledge of potentials on the surfaces of the scattering objects. The potential is typically computed by a numerical approximation of an integral equation that is defined on the surface. We first develop such numerical methods in time domain for the scalar wave equation. The efficiency of the techniques are improved by analytic quadrature and in some cases by local approximation of the potential.</p><p>Most scattering simulations are done for harmonic or single frequency waves. In the electromagnetic case the corresponding integral equation method is called the method of moments. This numerical approximation is computationally very costly for high frequency waves. A simplification is suggested by physical optics, which directly gives an approximation of the potential without the solution of an integral equation. Physical optics is however only accurate for very high frequencies.</p><p>In this thesis we improve the accuracy in the physical optics approximation of scalar waves by basing the computation of the potential on the theory of radiation boundary conditions. This theory describes the local coupling of derivatives in the wave field and if it is applied at the surface of the scattering object it generates an expression for the unknown potential. The full wave field is then computed as for other integral equation methods.</p><p>The new numerical techniques are analyzed mathematically and their efficiency is established in a sequence of numerical experiments. The new on surface radiation conditions give, for example, substantial improvement in the estimation of the scattered waves in the acoustic case. This numerical experiment corresponds to radar cross-section estimation in the electromagnetic case.</p>

Wave scattering is the phenomenon in which a wave field interacts with physical objects. An incoming wave is scattered at the surface of the object and a scattered wave is produced. Common practical cases are acoustic, electromagnetic and elastic wave scattering. The numerical simulation of the scattering process is important, for example, in noise control, antenna design, prediction of radar cross sections and nondestructive testing. Important classes of numerical methods for accurate simulation of scattering are based on integral representations of the wave fields and theses representations require the knowledge of potentials on the surfaces of the scattering objects. The potential is typically computed by a numerical approximation of an integral equation that is defined on the surface. We first develop such numerical methods in time domain for the scalar wave equation. The efficiency of the techniques are improved by analytic quadrature and in some cases by local approximation of the potential. Most scattering simulations are done for harmonic or single frequency waves. In the electromagnetic case the corresponding integral equation method is called the method of moments. This numerical approximation is computationally very costly for high frequency waves. A simplification is suggested by physical optics, which directly gives an approximation of the potential without the solution of an integral equation. Physical optics is however only accurate for very high frequencies. In this thesis we improve the accuracy in the physical optics approximation of scalar waves by basing the computation of the potential on the theory of radiation boundary conditions. This theory describes the local coupling of derivatives in the wave field and if it is applied at the surface of the scattering object it generates an expression for the unknown potential. The full wave field is then computed as for other integral equation methods. The new numerical techniques are analyzed mathematically and their efficiency is established in a sequence of numerical experiments. The new on surface radiation conditions give, for example, substantial improvement in the estimation of the scattered waves in the acoustic case. This numerical experiment corresponds to radar cross-section estimation in the electromagnetic case.

Rapid economic evaluations of investment alternatives in the oil and gas industry are typically contingent on fast and credible evaluations of reservoir models to make future forecasts. It is often important to also quantify inherent risks and uncertainties in these evaluations. These ideally require several full-scale numerical simulations which is time consuming, impractical, if not impossible to do with conventional (Finite Difference) simulators in real life situations. In this research, the aim will be to improve on the efficiencies associated with these tasks. This involved exploring the applications of Fast Marching Methods (FMM) in both conventional and unconventional reservoir characterization problems. In this work, we first applied the FMM for rapidly ranking multiple equi-probable geologic models. We demonstrated the suitability of drainage volume, efficiently calculated using FMM, as a surrogate parameter for field-wide cumulative oil production (FOPT). The probability distribution function (PDF) of the surrogate parameter was point-discretized to obtain 3 representative models for full simulations. Using the results from the simulations, the PDF of the reservoir performance parameter was constructed. Also, we investigated the applicability of a higher-order-moment-preserving approach which resulted in better uncertainty quantification over the traditional model selection methods. Next we applied the FMM for a hydraulically fractured tight oil reservoir model calibration problem. We specifically applied the FMM geometric pressure approximation as a proxy for rapidly evaluating model proposals in a two-stage Markov Chain Monte Carlo (MCMC) algorithm. Here, we demonstrated the FMM-based proxy as a suitable proxy for evaluating model proposals. We obtained results showing a significant improvement in the efficiency compared to conventional single stage MCMC algorithm. Also in this work, we investigated the possibility of enhancing the computational efficiency for calculating the pressure field for both conventional and unconventional reservoirs using FMM. Good approximations of the steady state pressure distributions were obtained for homogeneous conventional waterflood systems. In unconventional system, we also recorded slight improvement in computational efficiency using FMM pressure approximations as initial guess in pressure solvers.