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M. Tech. Electrical Engineering. / This dissertation presents vision-based systems for monitoring model breakwater armour structures. These model breakwater armour structures are subjected to wave simulations in model halls. The goal of this research was to produce a system that is able to detect changes in the model breakwater armour structure. These changes are detected autonomously or semi-autonomously depending on the method being used. The proposed systems are intended to replace the current flicker technique method, which is subject to human error. This dissertation reviews common image processing methods for monitoring changes in three dimensions. This review refines the search to two techniques, namely the stereopsis and fiducial methods. Each method approaches the problem differently. The stereo method treats the entire structure as a holistic 2.5D volume and shows changes in this volume. In the fiducial method special fiducial targets are attached to key areas on the breakwater armour units. The targets are tracked to compute displacement vectors.

M. Tech. Electronic Engineering. / Discusses the main objective of this research to develop a robust image-based algorithm to detect and determine the orientation of small helipad using shape descriptors and associated pre-processing techniques.

published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Master / Master of Philosophy

A novel cell culture system was designed to serve as a model of neuroinflammation. Neurons, astrocytes, and microglia derived from embryonic and perinatal rat cortical tissue were combined in a three-dimensional hydrogel utilizing a method that facilitated cell maturation and viability. Chemical challenge of the cultures with a broad pro-inflammatory stimulus resulted in the production of inflammatory cytokines and other associated molecules commensurate with the response observed in vivo and in other in vitro systems. It was hypothesized that mechanical deformation of the multitypic neural cell cultures would produce a similar response and thus validate the system as an in vitro model of traumatic brain injury-induced neuroinflammation. Mechanical injury delivered using custom-manufactured culture chambers and injury devices successfully imparted a moderate level of cell death to the cultures. It was determined that a mechanically-induced inflammatory response required chemical stimulation prior to the injury. The research presented here describes the generation and characterization of a novel in vitro culture system and its implementation in experiments designed to model secondary injury mechanisms associated with injury-induced neuroinflammation. The findings of these studies, applications of the culture system, and future research avenues are discussed.

No description available.

Background: The applications for rapid prototyping have expanded dramatically over the last 20 years. In recent years, additive manufacturing has been intensely investigated for surgical implants, tissue scaffolds, and organs. There is, however, scant literature to date that has investigated the viability of 3D printing of surgical instruments. Materials and Methods: Using a fused deposition manufacturing (FDM) printer, an army/ navy surgical retractor was replicated from polylactic acid (PLA) filament. The retractor was sterilized using standard FDA approved glutaraldehyde protocols, tested for bacteria by PCR, and stressed until fracture in order to determine if the printed instrument could tolerate force beyond the demands of an operating room. Results: Printing required roughly 90 minutes. The instrument tolerated 13.6 kg of tangential force before failure, both before and after exposure to the sterilant. Freshly extruded PLA from the printer was sterile and produced no PCR product. Each instrument weighed 16g and required only $0.46 of PLA. Conclusions: Our estimates place the cost per unit of a 3D printed retractor to be roughly 1/10th the cost of a stainless steel instrument. The PLA Army/ Navy is strong enough for the demands of the operating room. Freshly extruded PLA in a clean environment, such as an OR, would produce a sterile, ready to use instrument. Due to the unprecedented accessibility of 3D printing technology world wide, and the cost efficiency of these instruments, there are far reaching implications for surgery in some underserved and less developed parts of the world.

The objective of this research is to identify the circulation patterns of the water and sediment fluxes in coastal and estuarine zones, where the shoaling processes correlate with tide generating flow patterns. The research provides a better understanding of the characteristics of spatial and temporal variability of currents. An important deviation from previous research is the inclusion of the baroclinic term, which becomes very important in density driven flows. The understanding of this process provides a basis for determining how the water circulation three-dimensionally controls the hydrodynamics of the system and ultimately transports the suspended and soluble materials due to combined currents and waves. A three-dimensional circulation model is used to calculate the water circulation. The model is based on the three-dimensional (3D) version of Advanced Circulation (AD-CIRC) Hydrodynamic Model with extending the Sediment Transport module. The model is based on the finite element method on unstructured grids. The output of the hydrody-namic model is used to estimate spatial and temporal advections, dispersions and bottom shear stress for the erosion, suspension, deposition and transport of sediment. The model development includes extending the existing three-dimensional (3D) ADCIRC Model with (1) baroclinic forcing term and (2) transport module of suspended and soluble materials. The transport module covers the erosion, material suspension and deposition processes for both cohesive and non-cohesive type sediments. The inclusion of the baroclinic demonstrates the potential of over or underpredicting the total net transport of suspended cohesive sediment under influence of currents. The model provides less than 6% error of theoretical mass conservation for eroded, suspended and deposited sediment material. The inclusion of the baroclinic term in stratified water demonstrates the prevailing longshore sediment transport. It is shown that the model has an application to the transport of the cohesive sediments from the mouth of the Mississippi River along the north shore of the Gulf of Mexico towards and along the Texas coast. The model is also applicable to determine the design erosion thickness of a cap for isolating contaminated dredged material and to evaluate the appro-priate grain size of cap sediments to minimize the erosion.

In order to predict the behavior of bubbly flows, it is necessary to know the three dimensional profiles of the bubbles present in the flow. With advancements in the field of flow visualization, accurate reconstruction of the bubble shape has become necessary. The PIV and the SIV techniques, used to acquire images of particles and bubbles, have been found to be extremely useful in this regard. The study, development, implementation, applications and limitations of a unique reconstruction technique applied to various regular and irregular bubble shapes, using the two orthogonal projections of the three-dimensional bubble profiles as captured by the SIV cameras are presented here. The technique is a blend of neural networks, combinatorial optimization and advanced computer aided design methods. The technique involves the robustness and ruggedness of the neural network approach and the flexibility and reliability of advanced computer aided design methods. The technique uses a well-known problem in neural networks and combinatorial optimization known as the Traveling Salesman Problem approach to identify the bubble boundaries on the images. An optimization solution technique known as the Simulated Annealing technique is employed to solve the Traveling Salesman Problem and obtain the bubble profiles. These results are employed to reconstruct bubble shapes using NURBS computer aided design software. Two main applications of this technique are demonstrated and the results are found to be promising. The first application included the calculation of the void fraction at a particular depth of the channel/ pipe and at a particular radius of the channel. The second application was Lagrangian tracking of bubbles, wherein the centroids of the bubbles were tracked between image frames to determine the linear and transverse velocities of the bubbles. This technique has shown scope for development including the development as integrated bubble surface reconstruction software and advanced modifications at various levels for efficient and accurate reconstruction.

Vishet som fenomen har en lång historia, dock har begreppet under de senaste åren uppmärksammats allt mer av empirisk forskning. Det råder oenigheter kring fenomenets innebörd. Många studier visar dock att vishet kännetecknas av kognitiva och reflekterande dimensioner - precis som i Ardelts teori där vishet förklaras genom kognitiva, affektiva och reflekterande egenskaper. Denna studie utgår från Ardelts teori. En enkätundersökning med 110 deltagare genomfördes med syftet att utforma ett för arbetslivet modifierat vishetsformulär. Dessutom ämnade studien jämföra kön, ålder och privat respektive kommunal sektor. Resultatet visade hög korrelation mellan det modifierade vishetsformuläret (ViA) och Ardelts tredimensionella visdomsskala (3D-WS). Dessutom visade resultatet att privat sektor erhöll signifikant högre poäng än kommunal sektor i 3D-WS, samt att kvinnor i snitt fick högre poäng än män. Åldersskillnader påvisades inte. Studiens brister i form av bland annat representativitet, antalet deltagare och utformningen av enkäten diskuterades.