High-speed laser triangulation 3D cameras, such as the Ranger3 from SICK, transmit image data to a PC for processing. The camera’s operational speed is constrained by the capabilities of the transmission link. By compressing the data, the bandwidth requirements of the camera is reduced. This thesis presents the development of a lossless image compression format developed for this purpose. The proposed image compression format features a single-pass encoder that utilizes run-length and delta encoding. It is designed to be suitable for implementation on field-programmable gate arrays (FPGAs) within high-speed laser-scanning cameras. Furthermore, the format offers configurability through parameters, enabling optimization for diverse types of image data to achieve more efficient compression. The compression ratio of the image compression format was evaluated using a range oftypical images captured by a Ranger3 camera. The compression ratio was measured across different configurations of the format and subsequently compared with that of PNG. The compression ratio achieved by the proposed format is on par with that of the PNG format, despite having a much simpler encoding process.

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The O*NET was built to replace the Dictionary of Occupational Titles (DOT) and form a highly accessible, on-line (through the World Wide Web), common language occupational information center (Dye & Silver, 1999). This study tested the relevance of the self-rating choice and unconventional BARS format to be used by the O*NET system for occupational ratings. In addition, a new rating scale format named NBADS, was tested for improved ratings. Fifty three Incumbent raters in two occupations (Graduate teaching assistants and Secretaries) and 87 laypeople raters who have never worked in these occupations, rated 21 item-pairs (Importance and Level type questions) picked randomly from the 52 items on the original O*NET Ability questionnaire. Participants rated each of the 21 item-pairs three times, with the Level question being presented in the O*NET BARS, a Likert GRS and the NBADS formats; The importance type question was always rated using a 1-5 Likert scale. Hypothesis 1a was supported, showing a significant leniency bias across formats for self-ratings. Hypothesis 1b was mostly supported, failing to show significant leniency, elevation error or interrater agreement improvement over laypeople ratings; only the overall-error measure showed a significant improvement for incumbent raters. Hypothesis 2 was not supported, failing to show that the GRS format had any improvement on leniency, accuracy or interrater agreement over the O*NET BARS format. Hypothesis 3a was supported, showing significant leniency reduction, accuracy error reduction and higher interrater agreement using the NBADS format over the GRS format. In a similar sense, hypothesis 3b was partially supported, showing reduction in leniency effect and higher agreement using the NBADS format over the O*NET BARS format. Finally, hypothesis 4 was mostly supported, showing hardly any significant differences in the ratings of the Importance type question across the three format sessions, strengthening the idea that no other interfering variables have caused the format sessions' differences. Implications of the results are discussed. / Master of Science

The overall goal of this research work is to enhance the capabilities of large-format, polymer material extrusion, additive manufacturing (AM) systems. Specifically, the aims of this research are to (1) Construct, and develop a robust workflow for, a large-format, robotic, AM system; (2) Develop an algorithm for determining and relaying proper rotation commands for 5 degree of freedom (DoF) multi-axis deposition; and (3) Create a method for printing a removable support material in large-format AM. The development and systems-integration of a large-format, pellet-fed, polymer, material extrusion (ME), AM system that leverages an industrial robotic arm is presented. The robotic arm is used instead of the conventional gantry motion stage due to its multi-axis printing ability, ease of tool changes for multi-material deposition and/or subtraction, and relatively small machine footprint. A novel workflow is presented as a method to control the robotic arm for layer-wise fabrication of parts, and several machine modifications and workflow enhancements are presented to extend the multi-axis manufacturing capabilities of the robot. This workflow utilizes existing AM slicers to simplify the motion path planning for the robotic arm, as well as allowing the workflow to not be restricted to a single robotic deposition system. To enable multi-axis deposition, a method for generating tool orientations and resulting deposition toolpaths from a geometry's STL file was developed for 5-DoF conformal printing and validated via simulation using several different multi-DOF robotic arm platforms. Furthermore, this research proposes a novel method of depositing a secondary sacrificial support material was created for large-format AM to enable the fabrication of complex geometries with overhanging features. This method employs a simple tool change to deposit a secondary, water-soluble polymer at the interfaces between the part and supporting structures. In addition, a means to separate support material into smaller sections to extend the range of geometries able to be manufactured via large-format AM is presented. The resultant method was used to manufacture a geometry that would traditionally be considered unprintable on conventional large-format AM systems. / Master of Science / Additive manufacturing (AM), also known as 3D printing, is a method of manufacturing objects in a layer-by-layer technique. Large-format AM is typically defined as an AM system that can create an object larger than 1 m3. There are only a few manufacturers in the world of these systems, and all currently are built on gantry-based motion stages that only allow movement of the printer in three principal axes (X, Y, Z). The primary goal of this thesis is to construct a large-format AM system that uses a robotic arm to enable printing in any direction or orientation. The use of an industrial robotic arm enables printing in multiple planes, which can be used to print structures without support structures, print onto curved surfaces, and to purt with curved layers which produces a smoother external part surface. The design of the large-format AM system was validated through successful printing of objects as large as 1.0x0.5x1.2 m, simultaneous printing of a sacrificial support material to enable overhanging features, and through completing multi-axis printing. To enable multi-axis printing, an algorithm was developed to determine the proper toolpath location and relative orientation to the part surface. Using a part's STL file as input, the algorithm identifies the normal vector at each movement command, which is then used to calculate the required tool orientation. The tool orientations are then assembled with the movement commands to complete the multi-axis toolpath for the robot to perform. Finally, this research presents a method of using a second printing tool to deposit a secondary, water-soluble material to act as supporting structures for overhanging and bridging part features. While typical 3D printers can generally print sacrificial material for supporting overhangs, large-format printers produce layers up to 25 mm wide, rendering any support material impossible to remove without post-process machining. This limits the range of geometries able to be printed to just those with no steep overhangs, or those where the support material is easily reachable by a tool for removal. The solution presented in this work enables the large scale AM processes to create complex geometries.

Automated programming assignment grading tools have become integral to CS courses at introductory as well as advanced levels. However a lot of these tools have their own custom approaches to setting up assignments and describing how solutions should be tested, requiring instructors to make a significant learning investment to begin using a new tool. In addition, differences between tools mean that initial investment must be repeated when switching tools or adding a new one. Worse still, tool-specific strategies further reduce the ability of educators to share and reuse their assignments. As a solution to this problem, we describe our experiences working with PEML, the Programming Exercise Markup Language, which provides an easy to use, instructor friendly approach for writing programming assignments. Unlike tool-oriented data interchange formats, PEML is designed to provide a human friendly authoring format that has been developed to be intuitive, expressive and not be a technological or notational barrier to instructors. We describe the design of PEML and also discuss its implementation as a programming library, a web application, and a microservice that provides full parsing and rendering capabilities for easy integration into any tools or scripting libraries. We also describe the integration of PEML into two automated testing and grading tools used at Virginia Tech by the CS department: Code Workout and Web-CAT. We then describe our experiences using PEML to describe a full range of programming assignments, laboratory exercises, and small coding questions of varying complexity in demonstrating the practicality of the notation. We evaluate the feasibility of PEML using this encoding exercise as well as the effect of its integration into the aforementioned automated grading tools. We finally present a framework for integrating PEML into existing grading tools and then draw our conclusions as well as list down avenues PEML can be expanded into in the future. / Master of Science / Automated grading tools have become ubiquitous to CS courses focused on programming concepts at both the undergraduate as well as graduate level. These tools allow instructors to provide near instant feedback to students as well as spend more time focusing on the curriculum rather than grading. However, these tools use a variety programming assignment representation formats and without a standardized representation, instructors and educators may struggle to share and reuse assignments across different tools and platforms. To address this need, we have developed the Programming Exercise Markup Language (PEML), a standardized format for representing programming exercises, designed to be human-friendly as well as easy to learn and use. PEML includes information about the problem statement, input and output formats, constraints, and sample test cases, and can be used for a wide range of exercise types and programming languages. As part of this master's thesis project, we encoded 50 assignments of varying size and difficulty into PEML as well as integrated support for PEML into Web-CAT and Code Workout, two commonly used automated grading tools used at Virginia Tech. Building upon our experience performing this task, we also designed a framework that can be utilized when integrating PEML into other automated grading tools. By providing a standardized way of representing programming assignments, PEML can help to streamline programming education and make it easier for instructors and educators to create and share assignments across different tools and platforms.

Yes / Grounded in signaling theory, this paper investigates the signals reflecting product quality, innovativeness, reputation and cultural background which influence film performance, i.e. film survival (duration on cinema screen) and box office success, in China’s changing institutional context. This market has grown substantially and still possesses potential for further development. However, China’s unique institutional context presents challenges. By examining an expanded range of potential signals, two of which have not previously been examined in the literature, namely imported films and enhanced format film formats such as 3D and IMAX, we develop a conceptual framework and argue that signaling theory needs to be combined with institutional context. Similar to findings for film industries in other countries, we find quality and reputational signals including budget, star power, sequels, and online consumer reviews to be important in China. However, unique results are also revealed. Chinese consumers react to an innovativeness signal in that they are specifically attracted to enhanced format films. Film award nominations and prizes are insignificant reputational signals. Once other signals are taken into account, imported films on average do not perform as well as domestic films. We link these findings to China’s unique institutional setting and offer important implications for management, recognizing the challenges to film companies of competing in an increasingly globalized market. The paper is also of relevance to policymakers given their continued efforts in shaping the development of China’s film industry.