Maintaining Space Domain Awareness (SDA) of satellites in low Earth orbit (LEO) requires effective methods of tracking and characterization. Optical measurements of these objects are generally sparse due to limited access intervals and high angular rates. Light pollution and geographic obstructions may also preclude consistent observations. However, a mobile small aperture telescope grants the ability to minimize such environmental effects, thereby increasing capture likelihoods for objects within this regime. By enhancing LEO satellite visibility in this way, extensive orbital and visual data are obtainable. An 8-inch Meade LX200GPS telescope equipped with a Lumenera SKYnyx2-0M CCD camera comprises the system that conducted observations of LEO. From 22 sessions spanning four months, 76 objects were imaged to provide a data set of 313 streak frames for initial orbit and photometric analyses. An Assumed Circular Orbit formulation provided considerable refinements in semimajor axis and eccentricity, up to one order of magnitude, when compared to a Gauss Extended method. Regarding the use of initial orbits for future pass predictions, the Assumed Circular Orbit angular positions indicated improvements up to 97.4% in accuracy and 65.7% in consistency over Gauss Extended. A photometric study placed the brightest observed visual magnitude at 3.60 mag, and the faintest visible at 9.47 mag. By converting brightness to a physical size, detected objects were approximately 23.8 meters at the largest and 40.6 centimeters at the smallest. Angles and brightness measurements of LEO satellites with mobile platforms may thus benefit the SDA effort.

<p dir="ltr">In mass spectrometry, analyte molecules are ionized by various mechanisms, such that they can be manipulated by electric and magnetic fields. By performing such manipulations, the mass to charge (<i>m/z</i>) ratio of the analyte molecules can be measured. Many methods for ion manipulation that allow for such <i>m/z </i>determination have been developed in the form of different mass analyzers. These include but are not limited to magnetic/electric sector instruments, time-of-flight (TOF) mass analyzers, 3D quadrupole ion traps, quadrupole mass filters, linear quadrupole ion traps (LITs), Fourier-transform ion cyclotron resonance (FT-ICR) instruments, Orbitrap mass analyzers, and electrostatic linear ion traps (ELITs). Each of these mass analyzers has unique advantages and disadvantages resulting from its specific mechanism of operation, allowing each of these to find a niche in mass spectrometry applications. The ELIT is a mass analyzer composed of two opposing ion mirrors, which cause trapped high energy ions to oscillate along a linear axial trajectory. The oscillation period of ions in the ELIT is dependent on injection energy, the potential energy and electrode geometry of the ELIT, and the ion <i>m/z</i> ratio. As such, mass spectra can be measured by measuring the frequency of ion packets in the ELIT in Fourier-transform (FT) operation mode, or by or by allowing ions to separate spatially in an <i>m/z </i>dependent manner before detection via a microchannel plate (MCP) in multiple-reflection time-of-flight (MR-TOF) mode of operation. The ability to perform two orthogonal mass analysis techniques in a single mass analyzer is one key advantage of the ELIT. Both FT-MS, and MR-TOF mode of operation are high-resolution techniques, making the ELIT unique in its excellent performance characteristics despite low complexity and manufacturing cost. Additionally, the ELIT can be used to perform high-resolution ion isolations, which makes it especially attractive for tandem-MS.</p><p dir="ltr">In chapter 1, the operating principles for MR-TOF and FT-MS modes of operation in an ELIT are discussed. In chapter 2 and 3, the performance, limitations, and applications of the mirror-switching isolation technique in the ELIT are discussed. Given the high-resolution performance of the ELIT for both mass analysis and ion isolation, it is clear that the ELIT has great potential for tandem-MS applications which require high-resolution in either the precursor selection, mass analysis step, or both. In chapters 4, 5, and 6, the implementation and development of infrared multi-photon dissociation, and surface-induced dissociation techniques in the ELIT are discussed, and it is shown that the ELIT can be used to as a standalone tandem mass spectrometer. While not performed on the ELIT instrument, the charge-based valet parking technique discussed in chapter 7 applies to tandem-MS as a whole, as it is shown to improve fragment yield in ETD. Finally, in chapter 8, the future directions of development for the ELIT mass analyzer are discussed.</p>

<p>Presentation held over Zoom.</p>

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A Hyperspectral imager aboard a cubesat would be able to provide images which could be used to identify ships and determine the ship's length and breadth and heading. Depending on the size of the ship, the speed the ship is traveling can be determined as well; however the speed and size determination is limited by the spatial resolution of 100 meters. The spectral signature of the boat is dramatically different from the spectral signature of the open Ocean especially within the range of 400 to 1000 nanometers, and this threshold is the basis for extracting ship data. Hyperspectral Imagers are ideal for minimization with few optical errors introduced, and designs range in durability making them useful on board small satellites especially in the visible and near infrared region. Placing an imager on a satellite allows for consistent observation over a region to identify patterns in ship movement over time. / Master of Science

The fork-join framework project is one of the more challenging programming assignments in the computer science curriculum at Virginia Tech. Students in Computer Systems must manage a pool of threads to facilitate the shared execution of dynamically created tasks. This project is difficult because students must overcome the challenges of concurrent programming and conform to the project's specific semantic requirements. When working on the project, many students received inconsistent test results and were left confused when debugging. The suggested debugging tool, Helgrind, is a general-purpose thread error detector. It is limited in its ability to help fix bugs because it lacks knowledge of the specific semantic requirements of the fork-join framework. Thus, there is a need for a special-purpose tool tailored for this project. We implemented Willgrind, a debugging tool that checks the behavior of fork-join frameworks implemented by students through dynamic program analysis. Using the Valgrind framework for instrumentation, checking statements are inserted into the code to detect deadlock, ordering violations, and semantic violations at run-time. Additionally, we extended Willgrind with happens-before based checking in WillgrindPlus. This tool checks for ordering violations that do not manifest themselves in a given execution but could in others. In a user study, we provided the tools to 85 students in the Spring 2017 semester and collected over 2,000 submissions. The results indicate that the tools are effective at identifying bugs and useful for fixing bugs. This research makes multithreaded programming easier for students and demonstrates that special-purpose debugging tools can be beneficial in computer science education. / Master of Science

Despite advancements in automotive safety, motor vehicle collisions remain the leading cause of unintentional death for children ages 5 to 14. Enhancement of child occupant protection depends on the ability to accurately assess the effectiveness of restraint systems. Booster seat design and proper belt fit require evaluation using child anthropomorphic test devices, yet biofidelity of the abdomen and pelvis of the current anthropomorphic test device, the Hybrid III 6-year-old, needs improvement. Further, measurement of abdominal deflection is needed for quantification of the degree of submarining and associated potential injury risk. A biofidelic abdomen for the Hybrid III 6-year-old dummy is being developed by the Ford Motor Company. A practical measurement system for the biofidelic abdominal insert has been developed and demonstrated for three dimensional determination of abdominal deflection. Quantification of insert deflection is achieved via differential signal measurement using electrodes mounted within a conductive medium. Signal amplitude is proportional to the distance between the electrodes. A microcontroller is used to calculate distances between ventral electrodes and a dorsal electrode in three dimensions. This system has been calibrated statically, as well as evaluated dynamically. Its performance has also been demonstrated in a series of sled tests. Deflection measurements from the instrumented abdominal insert showed clear differences between two booster seat designs, yielding an average peak anterior to posterior displacement of the abdomen of 1.0 ± 3.4 mm and 31.2 ± 7.2 mm for the seats, respectively. Implementation of a 6-year-old abdominal insert with the ability to evaluate submarining potential will likely advance the effectiveness of booster seat design and restraint performance, and help mitigate child occupant injury severity in automobile collisions. / Master of Science

Current scoliosis corrective surgeries may include the use of multiple instrumentation devices including screws, wires, nuts, and rods. The instrumentation in most cases is implemented in its native form. However, the instrumentation rods must be contoured to a desired shape prior to fixation to the spine. The contouring of the instrumentation rod is currently performed manually and may require significant time for completion. This results in an increase of operation time and reduced accuracy of the instrumentation rod. The feasibility of automating the contouring process was studied to determine if the time required to contour a rod could be reduced and if the accuracy of the rod could be improved. This study built upon a previous effort to construct a prototype that would automate the manufacture of spinal instrumentation rods. The Spinal Instrumentation Bending Prototype (SIBP) focused on ease of use, time of manufacture, and accuracy. In order to complete the manufacturing process, the current SIBP uses a set of three dimensional control points that represent the desired contour of the rod. These control points are translated into manufacturing inputs that control the SIBP. The control application for the SIBP contains local and global feedback routines that correct for any manufacturing errors. A comparative study was made between the SIBP and an experienced orthopedic surgeon to determine the level of bending accuracy improvement. / Master of Science

A computer-based audiometric evaluation system has been developed. The system makes use of an IBM PC/XT/AT compatible personal computer to perform pure tone and speech tests and · comprises a plug-in card and custom software. The card contains pure tone and masking noise generators, together with amplifiers for a. set of headphones .and bone conduction transducer, patient and audiologist microphone amplifiers and a hand-held infra-red remote-control unit. A voice-operated gain-adjusting device on the audiologist's microphone eliminates the need for a sound pressure level meter during speech tests. The software-based user-interface makes use.of overlaid pop-up menus, context sensitive assistance.and a text editor on a graphics screen. Pure tone and speech data are acquired and displayed on a dynamic audiogram and speech discrimination gram respectively. This data may be stored and later retrieved from a patient data base. Further audiometric tests may be incorporated at a later stage.

ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / This paper describes a model of how to configure settings on instrumentation. For any given instrument there may be 100s of settings that can be set to various values. However, randomly selecting values for each setting is not likely to produce a valid configuration. By "valid" we mean a set of setting values that can be implemented by each instrument. The valid configurations must satisfy a set of dependency rules between the settings and other constraints. The formalization provided allows for identification of different sets of configurations settings under control by different systems and organizations. Similarly, different rule sets are identified. A primary application of this model is in the context of a multi-vendor system especially when including vendors that maintain proprietary rules governing their systems. This thus leads to a discussion of an application user interface (API) between different systems with different rules and settings.