Beamforming is a signal processing technique used in sensor arrays to direct signal transmission or reception. Beamformer combines input signals in the array to achieve constructive interference at particular angles (beams) and destructive interference for other angles. According to the following facts: 1- Beamforming can be computationally intensive, so real-time sonar beamforming algorithms in sonar devices is important. 2- Parallel computing has become a critical component of computing technology of the 1990s, and it is likely to have as much impact over the next 20 years as microprocessors have had over the past 20 [5]. 3- The high-performance computing community has been developing parallel programs for decades. These programs run on large scale, expensive computers. Only a few elite applications can justify the use of these expensive computers [2]. 4- GPU computing has the ability of parallel computing and it could be available on the personal computers. The objective of this thesis is to use Graphics Processing Unit (GPU) as real-time digital beamformer to accelerate the intensive signal processing.

This report presents FastBrush, an advanced implementation for real time brush simulation, which achieves high detail with a large amount of bristles, and is lightweight enough to be implemented for mobile devices. The final result of this system has far higher detail than available consumer painting applications. Paintbrushes have up to a thousand bristles. Adobe Photoshop is only able to simulate up to a hundred bristles in real-time, while FastBrush is able to capture the full detail of a brush with up to a thousand bristles in real-time on mobile devices. Simple multidimensional data driven modeling is used to create a deformation table, which enables calculating the physics of the brush deformations in near constant time for the entire brush, and thus the physics calculation overhead of a large number of bristles becomes negligible. The results show that there is a large potential for use of data driven models in high detail brush simulations. / Denna rapport presenterar FastBrush, en avancerad implementation för realtidssimulation av penselmålning som uppnår hög detalj med en stor mängd penselstrån, samt är snabb nog att implementeras för mobila enheter. Det slutgiltliga resultatet av denna implementation har mycket högre detail än nuvarande tillgängliga konsumentapplikationer. Penslar har ett tusen individuella penselstrån. Adobe Photoshop är begränsad till att simulera maximum ett hundra penselstrån, medan FastBrush kan uppnå fullständig detaljrik återgivning med upp till ett tusen penselstrån i realtid på mobila enheter. Enkel multidimensionell datadriven modellering används för att skapa en deformationstabell, vilket möjliggör att beräkna fysiken för penselns deformation i nära konstant tid, och därför blir de kostnaden av fysikkalkylationerna för ett högt antal individuella penselstrån försummbar. Resultaten visar att det finns stor potential för användning av datadrivna modeller i högdetaljerade penselsimulationer.

Digital in-line holographic microscopy (DIHM) has been incorporated as an additional simultaneous in situ optical technique with ellipsomicroscopy for surface imaging and microscopy to study metastable pitting corrosion on stainless steel 316LVM in simulated biological solutions. DIHM adds microscopic volume imaging, allows one to detect local changes of the index of refraction in the vicinity of a pitting event, and allows one to track tracer particles and/or material ejected from the pitting sites. To improve the pitting corrosion resistance of stainless steel 316LVM, a simple surface treatment was tested and the aforementioned imaging techniques were used to verify that pitting occurred only on the wire face. Treatments consisted of polishing the samples to remove the passive layer, then immersing the wires in 90 C nanopure water for several hours. Treated wires show a marked increase in pitting corrosion resistance over untreated wires: the pit initiation potential increases by a minimum of 200 mV. Additional testing with scanning electron microscopy and energy dispersive X-ray spectroscopy indicate that the removal of sulphide inclusions from the surface is the most probable cause of this enhancement. To increase holographic reconstruction performance, Graphics Processing Units (GPUs) have been used; 4 Mpixel holograms are reconstructed using the dot product approximation of the Kirchhoff-Fresnel integral in 60 ms on a Tesla c1060 GPU. Errors in sizes and positions can easily be as large as 5 to 10 % for regions where the dot product approximation is not valid, so algorithms with fewer or no approximations are also required. Reconstructions for arbitrary holographic geometries using the full Kirchhoff-Fresnel integral take approximately 1 hour (compared to 1 week on a quad-core CPU), and reconstructions using convolution methods, in which the results of 256 reconstructions at 4096 x 4096 pixels in one plane are combined, take 17 s. This method is almost exact, with approximations only in the obliquity factor.