Flame propagation through a channel equipped with obstacles was studied experimentally. Two types of obstacle geometries were investigated, i.e., wall-mounted cross-flow cylinders and fence-type obstacles mounted on the top and bottom channel surfaces. The motivation for this research is its applications to both high-speed propulsion and industrial explosion safety. The effect of obstacle distribution and blockage ratio on flame acceleration was investigated in a 2.54cm x 7.6cm “narrow” channel with wall-mounted cross-flow cylindrical obstacles. The cylinders were arranged in a “staggered” or “inline” pattern, with blockage ratios of 0.5 and 0.67. Schlieren images were used to study the flame shape and its leading edge velocity for a range of fuel-air mixtures compositions. It was determined that initial flame propagation occurs faster in higher blockage ratios due to the higher frequency perturbation to the flow. Flame acceleration led to different quasi-steady flame and detonation propagation regimes. In general, higher final steady flame velocities were reached in the lower blockage ratios, and detonation limits were found to be influenced by the geometry. The influence of channel width on flame acceleration was also determined using fence-type obstacles with a single blockage ratio. Experiments were performed in a 2.54cm x 7.6cm and 7.6cm x 7.6cm channel. Schlieren images were again used to study the flame shape and to obtain leading edge velocity. The flame tip was found to have a parabolic profile across the channel width for the narrower channel and flatter profile in the wider channel. It was determined that the channel width has a weak effect on the flame velocity down the channel length. As such, flame acceleration was initially only slightly more pronounced in the narrow channel before the reverse became true later in the wide channel. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2013-07-18 21:13:40.436

Syftet med examensarbetet är att klargöra hur lärare upptäcker och bemöter elever i fallenhet för matematik. Genom arbetet synliggörs även vilka material som används och på vilket sätt de syftar till att stimulera elever i fallenhet. Arbetet bygger på insamlad empiri i form av två intervjuer och analyser av de material som lärarna använder. Vid anlyseringen av empirin användes verksamhetsteorin och en verksamhetsmodell. Resultatet visar att lärare lärarna upptäcker elever i fallenhet på liknande sätt och att materialen som används oftast inte är anpassade för elever i fallenhet. De material som används är i huvudsak mängdtränande men det förekommer även en del berikande uppgifter. Slutsatserna som kunnat dras utifrån detta arbete är lärarna har stor vilja att bemöta och stimulera elever i fallenhet, men att tiden begränsar deras tillvägagångssätt. Trots de motsättningar som lärarna upplever finns inom verksamheten försöker de anpassa uppgifter och variera arbetssätt för att främja varje elevs kunskapsutveckling.

Raw acceleration can be used as a proxy measure representing external forces experienced at the hip. Peak vertical acceleration at the hip was measured (ActiGraph GT3X+ - BT) in 30 premenopausal women during common exercises (walking, running, stairs and jumping) and while they went about their normal routine (7 days). Accelerations experienced during running and jumping activities were consistently ≥3.2g, whereas only accelerations during box jumps were greater than the higher recommended threshold of ≥ 4.9g proposed to improve bone mineral density in premenopausal women. Peak jerk experienced during jumping activities was greater than the recommended threshold of 100g/s. The median number of accelerations/day ≥3.2g was 30.4, whereas only 3.5 incidences/day were observed at ≥4.9g. Running and jumping resulted in vertical accelerations that met or exceeded the thresholds proposed to be beneficial for bone, however, participants rarely experienced high magnitude vertical accelerations during daily life. / October 2016

Stochastic Rotation Dynamics (SRD) is a particle-based simulation method that can be used to model complex fluids either in two or three dimensions, which is very useful in biology and physics study. Although SRD is computationally efficient compared to other simulations, it still takes a long time to run the simulation when the size of the model is large, e.g. when using a large array of particles to simulate dense polymers. In some cases, the simulation could take months before getting the results. Thus, this research focuses on the acceleration of the SRD simulation by using GPU. GPU acceleration can reduce the simulation time by orders of magnitude. It is also cost-effective because a GPU costs significantly less than a computer cluster. Compute Unified Device Architecture (CUDA) programming makes it possible to parallelize the program to run on hundreds or thousands of thread processors on GPU. The program is divided into many concurrent threads. In addition, several kernel functions are used for data synchronization. The speedup of GPU acceleration is varied for different parameters of the simulation program, such as size of the model, density of the particles, formation of polymers, and above all the complexity of the algorithm itself. Compared to the CPU version, it is about 10 times speedup for the particle simulation and up to 50 times speedup for polymers. Further performance improvement can be achieved by using multiple GPUs and code optimization.

" In the field of Robotics, Monocular Simultaneous Localization and Mapping (Monocular SLAM) has gained immense popularity, as it replaces large and costly sensors such as laser range finders with a single cheap camera. Additionally, the well-developed area of Computer Vision provides robust image processing algorithms which aid in developing feature detection technique for the implementation of Monocular SLAM. Similarly, in the field of digital electronics and embedded systems, hardware acceleration using FPGAs, has become quite popular. Hardware acceleration is based upon the idea of offloading certain iterative algorithms from the processor and implementing them on a dedicated piece of hardware such as an ASIC or FPGA, to speed up performance in terms of timing and to possibly reduce the net power consumption of the system. Good strides have been taken in developing massively pipelined and resource efficient hardware implementations of several image processing algorithms on FPGAs, which achieve fairly decent speed-up of the processing time. In this thesis, we have developed a very simple algorithm for feature detection in an indoor environment by means of a single camera, based on Canny Edge Detection and Hough Transform algorithms using OpenCV library, and proposed its integration with existing feature initialization technique for a complete Monocular SLAM implementation. Following this, we have developed hardware accelerators for Canny Edge Detection & Hough Transform and we have compared the timing performance of implementation in hardware (using FPGAs) with an implementation in software (using C++ and OpenCV). "

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND AERONAUTICS. / Vita. / Bibliography: leaves 233-238. / by Byron Kurt Lightenberg. / Sc.D.

Ray tracing acceleration methods are usually applied to scenes defined by triangle meshes.These scenes contain a large number of triangles. In contrast, CSG scenes contain orders of magnitude less more complex primitives primitives. In this thesis we will present the Operation KD-tree. This acceleration method applies the KD-tree --- modern acceleration method developed for triangle meshes --- directly to the CSG scene. This is done on the premise, that the huge reduction in primitive count will yield enhanced performance, when rendering a scene using CSG instead of triangle meshes.

<p>Mitrionics is a company based in Lund, Sweden. They develop a platform for FPGA-based acceleration, the platform includes a virtual processor, the Mitrion Virtual Processor, that can be custom built to fit the application that is to be accelerated. The purpose of this thesis is to investigate the possible benefits of using a centralized scheduler for the Mitrion Virtual Processor instead of the current solution which is a distributed scheduler. A centralized scheduler has been implemented and evaluated using a set of benchmark applications. It has been found that the centralized scheduler can decrease the number of registers used to implement the Mitrion Virtual Processor on an FPGA. The size of the decrease depends on the application, and certain applications are more suitable than others. It has also been found that the introduction of a centralized scheduler makes it more difficult for the place and route tool to fit a design on the FPGA resulting in failed timing constraints for the largest benchmark application.</p> / <p>Mitrionics är ett företag i Lund. De utvecklar en platform för FPGA-baserad acceleration av applikationer. Platformen innehåller bland annat en virtuell processor, Mitrion Virtual Processor, vilken kan specialanpassas till applikationen som ska accelereras. Syftet med detta arbete är att implementera en centraliserad schedulerare för Mitrion Virtual Processor och utvärdera vilka möjliga fördelar det kan finnas jämfört med att använda den nuvarande lösningen vilket är en distribuerad skedulerare. En centraliserad skedulerare har implementerats och utvärderas genom att avända en uppsättning testapplikationer. Det har funnits att användandet av en centraliserad skedulerare kan minska antalet register som behövs för att implementera Mitrion Virtual Processor på en FPGA. Vidare har det funnits att storleken på minskningen beror på applikationen och att vissa applikationer lämpar sig bättre än andra. Det har även visat sig att processen att placera logik på FPGAn blir svårare om man använder en centraliserad skedulerare, detta har resulterat i att vissa timing krav inte har mötts när den största testapplikation har syntetiserats.</p>

<p>Sammanfattning</p><p><strong>Bakgrund: </strong>Fotboll är världens största lagidrott med ca 240 miljoner utövare runtom i väldren. Av dessa 240 miljoner är ca 20 miljoner kvinnor och 80% av dessa kvinnor är ungdomar eller juniorer. Accelerationshastighet anses vara en av de viktigaste fysiska egenskaperna hos fotbollsspelare.</p><p><strong>Syfte: </strong>Syftet med denna studie var att designa, genomföra och utvärdera ett träningsprogram för unga fotbollsspelande tjejer med syfte att öka accelerationshastigheten.</p><p><strong>Metod: </strong>22 stycken tjejer (14,61 ± 1,03 år, 50,33 ± 5,05 kg, 160,16 ± 3,04 cm) tillhörande 2 olika fotbollslag delades in i 2 grupper, en testgrupp (TG) (n=8) och en kontrollgrupp (KG) (n=14). Träningsmängden för båda grupperna var 3 pass/vecka i 12 veckor. Ett pass/vecka var designat i syfte att öka accelerationshastigheten för TG. KG tränade fotboll som vanligt alla 12 veckor.</p><p><strong>Resultat: </strong>I TG sågs en tendens till ökad acceleration i sprinttestet (p=0,08) och en signifikant förbättring i hopptestet (p=0,03) efter 12 veckors träning. Accelerationsträningen visade även ge signifikanta korrelationer mellan sprint- och hopptestet i TG efter avslutad träningsperiod (p=0,02). I KG ökade tiderna på sprinttestet (p=0,02) och den vertikala hopphöjden minskade i hopptestet (p=0,12) vid utvärdering 2. Det fanns en signifikant korrelation mellan sprint- och hopptestet för KG vid både utvärdering 1 och 2 Det fanns inga signifikanta skillnader mellan grupperna.</p><p><strong>Slutsats: </strong>Ett 12 veckors träningsprogram kan öka accelerationshastigheten och den vertikala hopphöjden hos unga fotbollsspelande tjejer.</p> / <h2>Abstract</h2><p><strong>Background: </strong>Soccer is the world’s most popular team sport with over 240 million players around the world. About 20 million of the 240 million players are women and 80% of these women are adolescence or juniors. Acceleration speed is one of the most important physical qualities for a soccer player.</p><p><strong>Purpose: </strong>The aim of this study was to design, perform and evaluate a training program for young female soccer players with focus on increasing the acceleration speed.</p><p><strong>Methods: </strong>22 females (14,61 ± 1,03 years, 50,33 ± 5,05 kg, 160,16 ± 3,04 cm) from two different teams were split in 2 groups, one test group (TG) (n=8) and control group (KG) (n=14). The amount of training were 3 times/week for 12 weeks. One workout/week was designed to increase the acceleration speed for TG. KG trained soccer all 12 weeks.</p><p><strong>Results: </strong>TG showed a tendency to increased acceleration at the sprint test (p=0,08) and significant improvement at the jump test (p=0,03) after 12 weeks of training. The acceleration training also showed significant correlations between the sprint- and jump test in the TG after completed the 12 week training period (p=0,02). KG showed decreased acceleration at the sprint test (p=0,02) and the vertical jump height decreased at the jump test (p=0,12). There was a significant correlation between the sprint- and jump test in KG at both evaluation 1 and 2. There were no significant differences between the two groups.</p><p><strong>Conclusion: </strong>A 12 week training program can increase the acceleration speed and the vertical jump height on young female soccer players</p>

The purpose of this study was to determine kinetic and kinematic characteristics of Thai Boxing Roundhouse Kicks. In order to measure the kinetic variables of peak force and impulse, a triaxial accelerometer was inserted into a kicking bag. The force data were derived from the known mass and measured acceleration of the kicking bag. Validation testing comparing applied forces to estimated forces based on accelerometers output showed this instrument provided accurate estimates of the force applied to the kicking bag (r=.99). The MacReflex motion analysis system was utilized with three cameras operating at 120 frames per second to obtain the kinematic characteristics of final linear velocity of the kicking ankle, linear velocity of the kicking ankle and knee, angular velocity of the knee, and the angular velocity of the shank and thigh projected onto the horizontal plane. The subjects were ten male Thai Boxing performers with 8 to 48 months of training experience. The kicking trials were conducted at three height levels. It was hypothesized that the peak force, impulse, and the final linear velocity of the kicking ankle at impact would be greater for the lower level of kicks as compared to the higher level of kicks. It was also hypothesized that peak force and impulse would be positively related the subjects' leg strength. For the relationship between kinetic variables and kinematic variables it was hypothesized that peak force and impulse would be positively related to the final linear velocity of the kicking ankle. In comparing the roundhouse kick at different height levels the middle level kick generated the greatest peak force and impulse, while the high level kick involved the least force and impulse. The amount of peak force and impulse were directly related to the final velocity of the ankle (r=.86, and r=.79 respectively), but they were not significantly related to the leg strength. This study found that the Thai Boxing roundhouse kick can easily generate enough force to cause neurological impairment, skull fractures, facial bone fractures, and rib fractures. These results suggest that there is a greater need for regulations protecting the competitors in Thai Boxing. / Graduation date: 1997