The thesis presented is an effort to gather all possible information of one particular type of common paint defect the seed defect, from gray scale images of highly specular painted surface. The proposed approach in the thesis utilizes a white light source to illuminate the surface and utilizes a camera to capture its gray scale image at different diffused angles. While attempting to explain the physics of highlight formation in terms of location on the surface of a seed defect, the thesis also extends to utilize this information from gray scale images to accurately predict the parameters of seed defects including the height, size and position in real time. Since the primary highlight in a gray scale image is more defined, contrary to the past researches on diffuse angle images that use both primary / seed highlight and mirror highlight to estimate height of the seed, this thesis formulates a theory of highlight translation and estimates the height of seed based on primary / seed highlight. The other common type of surface defect - crater defect, is also addressed in the thesis.

Syfte: Att med hjälp av videoanalys och programvaran Dartfish, undersöka eventuella skillnader i stödfasen på vinkeln mellan calcaneus och underlaget, hos personer med Pes planus och pes cavus, både efter en- och 45 minuters löpning på löpband.  Studiedesign: En experimentell studie. Metod: Trettiofyra personer vars fot/fötter uppmättes till pes cavus och pes planus enligt kriterierna för Medial Longitudinale Arch -angle, inkluderades i studien. Mätningarna gjordes på en stillbild med digital goniometer i programvaran Dartfish. Därefter mättes calcaneus vertikala mittlinje i förhållande till underlaget i stödfasen både efter 1 minut och 45 minuter, när försökspersonerna sprang barfota på ett löpband. Resultat: Båda fotvalvsgrupperna visade ett signifikant lägre värde, d vs ökad valgusriktning av calcaneus till underlaget, efter 45 minuter jämfört med 1 minuts löpning (p<0.05). Konklusion: Både pes cavus och pes planus tenderar att inta en calcaneusställning mer åt valgus efter 45 minuters löpning. Det behövs fortsatt forskning för att klargöra förändringen av biomekaniken efter längre tids löpning. Studiens resultat antyder att framtida studier som undersöker sambandet mellan skador och abnormala fotrörelser under belastning  även bör undersöka efter längre tids löpning.

The objective of this research was to better understand how impact angle influences headform dynamic response and brain tissue deformation. A bare headform was impacted using a pneumatic linear impactor at 5.5 m/s. The impacts were directed on the front and side location at angles of 0, 5, 10 and 15° rightward rotations as well as -5, -10 and -15° (leftward) rotations at the side to examine the characteristics of the head and neckform on the results. Peak resultant linear and rotational accelerations from the headform as well as peak maximum principal strain (MPS) and von Mises stress (VMS) estimated from a brain finite element model were used to measure the effect of impact angle. Significant results were dependent upon the impact angle and location as well as the dependent variable used for comparison (p <0.05). Impact angle produced significant differences in rotational acceleration and MPS at both the front and side; however angle only had an effect on VMS and linear acceleration at the front and side locations, respectively. These findings show that the effect of impact angle is asymmetrical and is specific to the dependent variable. This study suggests that varying impact angle alone may not be as influential on headform dynamic response and brain tissue deformation and that the severity of an impact may be more of a function of how both location and angle create high risk conditions.

In this work we introduce PARETO, a multiobjective optimization tool that simultaneously optimizes beam angles and fluence patterns in intensity-modulated radiation therapy (IMRT) treatment planning using a powerful genetic algorithm. We also investigate various objective functions and compare several parameterizations for modeling beam fluence in terms of fluence map complexity, solution quality, and run efficiency. We have found that the combination of a conformity-based Planning Target Volume (PTV) objective function and a dose-volume histogram or equivalent uniform dose -based objective function for Organs-At-Risk (OARs) produced relatively uniform and conformal PTV doses, with well-spaced beams. For two patient data sets, the linear gradient and beam group fluence parameterizations produced superior solution quality using a moderate and high degree of modulation, respectively, and had comparable run times. PARETO promises to improve the accuracy and efficiency of treatment planning by fully automating the optimization and producing a database of non-dominated solutions for each patient.

The field of Spintronics, which utilizes the spin polarization of electrons as a means to transport energy and information, is currently undergoing a massive expansion due to the numerous recent discoveries of electron spin-based effects only visible at the micro and nano scale. With all these new material and current based properties being discovered, it has become increasingly difficult to experimentally isolate the effects of each of them individually. In this work one of the main proposals is an experimental method for separating the voltage signals generated by the spin rectification effect and spin pumping in bilayer samples, a topic currently of much interest to the spintronics community. After demonstrating this new method for separating voltage signals, it is utilized to reveal new details about how the layers of ferromagnetic bilayer samples interact with each other and the behaviours of spin currents within these systems.

The study of infinitely long cylinders of constant cross-section floating in an infinite fluid bath in zero-gravity environments has primarily been focused on bodies whose cross-sections are strictly convex and sufficiently smooth. In this thesis, our efforts are concentrated on the consideration of bodies that are only convex and piecewise smooth. These types of bodies are seldom considered in current literature. We have worked with a series expansion of the energy function in order to determine when configurations of a given body will be in equilibrium, stable or otherwise. We have proven that any convex body with a straight side cannot float in a stable equilibrium with the fluid interface intersecting the interior of the straight side in a single point. This fact is then used to prove necessary and sufficient conditions for stable equilibrium of polygons, bodies whose cross-sections are comprised of only straight sides. We illustrate these conditions with several examples. In the latter portion of the thesis, we turn our attention to bodies in three dimensions. While past research has again been focused on strictly convex bodies, we began to consider bodies that do not meet these requirements by examining bodies of revolution. A condition for stability with respect to vertical variations of bodies of revolution is derived. We conclude with several examples of bodies of revolution, some of which interestingly relate back to an analogous two-dimensional shape.

Graduation date: 1992

The stability of drops forced by both wind and gravity is a fluid mechanics problem relevant to heat exchangers, fuel cells, and aircraft icing. To investigate this phenomenon, drops from 15 micro-liters to 400 micro-liters were placed on the rough aluminum (RA = 3.26 micrometers) floor of a tiltable wind tunnel and brought to critical conditions, when the drop begins to run downstream. Various combinations of drop size, inclination angle, and flow speed were employed. A measurement technique capable of measuring full 3D drop profiles was implemented to investigate the drops' evolution toward runback. The measurement requires the comparison of the speckle pattern captured by an overhead drop image with a corresponding image of the dry surface. Stability limits for 235 drops are measured as functions of drop volume and surface inclination. Drops experiencing airflow alone are found to shed at a Weber number of 8.0 +/- 0.5. From measurement sequences of reconstructed drop profiles, the evolution of contact lines, drop profiles, and contact angle distributions are detailed. Contact line integral adhesion forces are calculated from contact angle distributions and related to the forcing air velocity. Drops whose stability limits are dominated by gravity are found to exhibit significantly different evolution toward runback than those dominated by airflow.

Esta Tesis Doctoral tiene como finalidad principal estudiar la fórmula metatarsal, de la huella plantar; en el podoscopio, de la pedigrafía, del fotopodograma, la baropodometría y aquellas que se derivan del análisis radiológico dorso plantar en posición bipodal y, finalmente la determinación del ángulo de rodación transmetatarsal.La presente memoria doctoral se ha centrado en el estudio de los métodos de registro podográfico con el fin de comparar distintos procedimientos. La importancia clínica de este estudio descansa en el hecho de que una buena práctica diagnostica en las primeras etapas de la vida, redundará muy posiblemente en una reducción de problemas clínicos de índole traumatológica en las etapas avanzadas de la vida. En poblaciones como la europea, en que la edad media de la población aumenta de forma continua, la prevención de las lesiones crónicas de cadera, rodilla dígito-metatarsales etc. constituirán posiblemente una de las zonas de acción más importantes de la medicina preventiva. Esta idea viene además reforzada por los criterios de coste económico; particularmente si se tiene en cuenta el valor de las prótesis, y el costo de las hospitalizaciones y la práctica quirúrgica necesarias para asegurar la calidad de vida en una proporción considerable de las personas de edad en las sociedades avanzadas. La hipótesis que se plantea en este trabajo de investigación consiste en la idea de que la secuencia y empuje de apoyo metatarsal influyen en factores estructurales y funcionales que hacen más complejo el desarrollo del tipo de marcha a nivel individual. Se pueden definir prácticamente tantas representaciones de secuencias en la rodación como individuos se estudien. La fórmula metatarsal y su interrelación con la pelvis y el raquis forma parte de la base de conocimiento de cara a establecer categorías con interés biomecánico y ergonómico. Fórmula metatarsal: Denominamos fórmula metatarsal a un criterio (en realidad no es una fórmula) que nos permite, como hemos indicado anteriormente clasificar todos los pies en tres categorías en función de la longitud del primero y segundo metatarsianoIndex Minus: el primer metatarsiano es más corto que el segundo. En tercero, cuarto y quinto de longitud decrecienteIndex Plus Minus: el primer metatarsiano y el segundo son iguales. El tercero, cuarto y quinto de longitud decreciente.Index Plus: el primer metatarsiano es más largo que el segundo. El tercero, cuarto y quinto de longitud decreciente.El estudio de la huella plantar ha evolucionado a lo largo de la historia, buscando siempre el establecimiento de parámetros de normalidad mediante el estudio y la somatometría de la impronta plantar. Nosotros hemos incluido en este estudio el ángulo de rodación determinado a través del triángulo de apoyo plantar metatarso-digital. Este ángulo nos informa y ayuda a predecir los eventuales trastornos futuros de la marcha, así como al diagnostico de alteraciones actuales. Tipómetro gravitatorio y rotacional:Para ello se ha diseñado un dispositivo mediante un goniómetro gravitatorio y una brújula, este tipómetro se ha construido para este trabajo, para las mediciones de las rotaciones,torsiones,inclinaciones y angulaciones. Mediante este instrumento de diseño original de diseño propio, se midieron los valores de las rotaciones verticales,las horizontales e inclinaciones. Con este trabajo de investigación se ha pretendido confirmar cómo varía, de un individuo a otro, las distribuciones de las presiones plantares cuando el pie esta en el máximo apoyo plantar y en el máximo apoyo metatarsal, y cómo se distribuyen estas presiones plantares, puesto que pueden condicionar la dinámica de la marcha toda vez que al utilizar diferentes técnicas de medición en una misma persona estos factores suelen variar.

The prospects for enhanced Positron Emission Tomography imaging using liquid xenon (LXe) gamma ray detectors had been examined. Monte-Carlo simulations using GEANT4 were performed and the results were used to study the expected performance of a small animal PET scanner in comparison with a simulated conventional small animal scanner (LSO Focus 120). A NEMA-like cylinder phantom and an image contrast phantom were simulated with both scanners to compare performance characteristics. A Compton reconstruction algorithm was developed for the LXe scanner, and its performance and limitations studied.