Browsing by Author "Dr. Wesley E. Snyder, Committee Member"

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    An Edge-detection and HPF Based Intelligent Space - A Network Based Integrated Navigation System.
    (2006-08-07) Gupta, Rachana Ashok; Dr. Mo-Yuen Chow, Committee Chair; Dr. Wesley E. Snyder, Committee Member; Dr. James Brickley, Committee Member
    Intelligent space (iSpace) is a large scale mechatronics system. It is a multidisciplinary effort whose aim is to produce a network structure and components that are capable of integrating sensors, actuators, DSP, communication, and control algorithms in a manner that suits time-sensitive applications including real-time navigation and/or obstacle avoidance. There are many challenges that must be overcome in order to put such a distributed, heterogeneous system together. The research presented here deals with one of these issues, i.e. the adverse effect of processing delays on the system. Here a novel structure for a delay-resistant sensory-motor module to navigate a differential drive unmanned ground vehicle (UGV) in a cluttered environment is suggested. The module consists of an early vision edge detection stage, a harmonic potential field (HPF) planner; a network based quadratic curve fitting controller and gain schedule middleware (GSM). The structure of this module and its components are described. Thorough experimental results along with performance assessment comparing to the previous implementation are also provided.
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    Thermosyphon Targets Designed for the Production of 18F for use in Positron Emission Tomography
    (2002-11-07) Roberts, Amy Nicole; Dr. Wesley E. Snyder, Committee Member; Dr. Joseph M. Doster, Committee Chair; Dr. Bruce W. Wieland, Committee Co-Chair
    ¹⁸F is a radioisotope commonly used in Positron Emission Tomography. One way to produce ¹⁸F is to bombard ¹⁸O enriched water with protons, generated by a cyclotron. The production reaction is ¹⁸>O(p,n) ¹⁸F. The purpose of this research was to model and build a more efficient target that can withstand higher proton beam currents and energies and produce greater yields of ¹⁸F. A thermosyphon was chosen as the basis for the target design. Thermosyphons transfer heat through evaporation and condensation. The concept is simple; the target water is allowed to boil and the water vapor rises out of the target chamber into a condenser region that is cooled along the outer surface. Condensation occurs along the condenser walls, and the condensate then runs down the length of the cylinder and back into the target chamber. The thermosyphon target model showed that this form of target design was feasible, withstanding greater proton beam currents and energies and producing more ¹⁸F than conventional targetry. Three separate thermosyphon targets, each increasing in condenser heat transfer surface area and volume, were built and their performance was experimentally validated. The results of both the model and the experimental targets are discussed in detail.