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More than seventy percent of Americans over the age of sixty are classified as overweight or obese, and the future incidence of these conditions is expected to rise. Although it is unclear why older adults are predisposed to weight gain, decreased total energy expenditure may contribute to positive energy balance. It is also possible that age-related impairments in energy intake regulation result in the inability to appropriately adjust food intake to meet energy requirements with advancing age. The purpose of these investigations was to determine the influence of age and habitual physical activity on acute regulation of energy intake. Secondary objectives were to determine if there are sex differences in energy intake regulation, and to determine if pre-meal water consumption decreases meal energy intake in young and older adults. To achieve these objectives, the ability to spontaneously adjust energy intake at a meal under "preloading" conditions in which a yogurt shake or water was consumed prior to the meal was determined. We hypothesized that older adults would demonstrate less accurate energy intake regulation than younger adults, but that energy intake dysregulation would be attenuated in physically active older adults. We also expected that young men would have higher accuracy of energy intake regulation compared to young women matched for dietary cognitive restraint and cardiorespiratory fitness, and that pre-meal water consumption would decrease meal energy intake in young and older adults. Our main finding was that energy intake regulation is significantly impaired in older compared to younger adults, and that habitual physical activity improves short-term, but not acute, energy intake regulation. We also found that young men demonstrate significantly higher accuracy of energy intake regulation compared to young women. Lastly, we determined that pre-meal water consumption significantly decreases meal energy intake in older, but not young, adults. Overall, these results indicate that acute energy intake regulation is less accurate with advancing age, but that regular physical activity improves short-term energy intake regulation. Additionally, sex appears to influence energy intake regulation, and water consumption is a potential strategy to reduce energy intake in older adults. / Ph. D.

Public criticism of executive pay has increased significantly in recent years. Shareholders express concern that the level of pay to many executives does not match the level of increase in shareholder wealth. The government has even gotten involved in the issue by changing tax laws related to compensation and taking an interest in how compensation is recorded in financial statements. This study investigates the relationship between adoption of compensation components and improved firm performance. Specifically, performance and restricted stock plan adoptions are analyzed for nine industries. Variable change is analyzed pre and post adoption for adopters; these adopters are then compared to non-adopters and to non-adopting peers. Data were gathered from COMPUSTAT and analyzed using four statistical methods; ttests, analysis of variance, multivariate analysis of variance and analysis of means. The study covers 20 years of adoptions and involves 335 adopting firms. Results of the study indicate that, when solely analyzing adopters, adoptions of performance or restricted stock plans improve firm performance for some industries but not for others. The study further indicates for most industry groups, the improvement experienced by adopters is not as significant as the improvement realized by the non-adopting segment of the industry. Lastly, when adopters are compared to non-adopting peers the study finds peers perform as well as or better than adopters. These results imply adoption of restricted stock plans works as intended for some industries by improving firm performance but may not improve performance to the levels reached by the industry as a whole. / Ph. D.

This thesis is centered upon the published A Novel Method and Exoskeletons for Whole-arm Gravity Compensation (Turner, Hull 2020), and includes a novel concept for supporting the weight of a person's arm or robotic linkage. The design is capable of supporting weights held near the hand, and provides support regardless of position. This support is provided with a pantograph. The upper-arm and forearm bars are mirrored by smaller copies. Force applied to a pull point on the scaled copy of the arm is flipped and applied at a support point on the forearm or to a tool near the hand. Two exoskeletons, using different linkages make use of the pantograph design. These include the Panto-Arm Exo, which uses it's slim, reduced size to comfortably assist users in lifting their arm, and the Panto-Tool Exo which is designed for a support point that coincides with a mass representing a heavy tool. The differing topologies and purposes of these two devices resulted in different qualities regarding their ability to lift weight. The Panto-Arm Exo was specifically used in human subject testing, in which fourteen users wore electromyography electrodes and performed simple arm movements and holding tasks. While the Panto-Arm Exo did not undergo stringent design improvements or user-specific optimization, the device was shown to reduce muscle use in the measured upper-arm muscles for certain arm positions. / Master of Science / This thesis is centered upon the published A Novel Method and Exoskeletons for Whole-arm Gravity Compensation (Turner, Hull 2020), includes a new way to lift a person's arm or robotic linkage. The design can lift weights close to the hand regardless of arm placement. This support is provided with a pantograph. The pantograph design is based on a mirrored, smaller copy of the upper-arm and forearm bars, which is pulled downwards to create an upwards support force at chosen support point. This point is based underneath the forearm or at a heavy tool. The concept is similar to pushing down on a teeter-totter in order to prevent the other end from dropping. Two exoskeletons, using different linkages make use of this pantograph design. The Panto-Arm Exo is slim and light. It is made to help users in lift their arm by supporting its weight. The Panto-Tool Exo has a support point that located where a mass representing a heavy tool sits. The changes between both devices means that they display different lifting qualities. The Panto-Arm Exo was worn by 14 people, also wearing electrodes that measured muscle activation. These users held weights and moved their arms around while muscle activation was recorded. While the Panto-Arm Exo wasn't fine-tuned or adjusted for individual people, it was shown to reduce muscle activation in the measured upper-arm muscles for some of the arm placements.

We present and analyze two arm exoskeletons based on a pantograph linkage that allow for the support of 89~N (20~pounds) at the user's hand. Using a pantograph linkage allows for a constant force to be created at the hand in any orientation when a constant vertical force is supplied to the other side of the pantograph. We present several topologies and analyze them based on feasibility of manufacture and ability to provide a near vertical force to the pantograph linkage. Simulations are created using the best topologies and the resulting forces at the hand are reported. The mechanical design of an unpowered (passive) exoskeleton which uses a gas spring mechanism is presented. Additionally, simulations and block-CAD of a powered (active) exoskeleton which uses a motor for the supply of force are presented. The performance of the passive exoskeleton is qualitatively compared with simulations. / Master of Science / A wearable device or exoskeleton is presented which is designed to help a user support a weight of 20 pounds (89~N) at their hand. A pantograph linkage arm exoskeleton provides forces to the hand which are equal to the force provided to the linkage divided by the linkage's ratio. Providing a force to the linkage that is purely vertical will result in a purely vertical force at the hand. Layouts of the exoskeleton components which produce a near-vertical force for the linkage are explored. The more promising layouts are simulated and the forces are compared based on how vertical the forces are. The design of an unpowered exoskeleton is also presented, which uses a gas spring mechanism to provide force. Additionally, simulation results for the unpowered exoskeleton and the basic design and analysis of a powered exoskeleton are presented.

Acoustic Frequency Domain Reflectometry (AFDR) is a novel technique employing frequency modulated continuous wave (FMCW) methods in solid acoustic waveguide reflectometry. It is particularly suited to dispersion compensation and phase compensation due to the measurement domain being the frequency domain. This work rigorously analyzes, develops, and experimentally demonstrates AFDR, alongside various compensation methods and demodulation techniques. Distributed measurement of temperature is tested using several novel signal processing algorithms for strain determination and is estimated to have a resolution of 0.58 °C over a 20 cm gauge length. An error correction algorithm to improve SNR in the measurement of strain is proposed and validated. The sensing system has a theoretical spatial resolution of 2 mm and an estimated sensing resolution limit of about 1 cm. AFDR and the associated signal processing developments are positioned to be transformative across many areas of acoustics, with significant potential for distributed sensing along an acoustic waveguide. / Doctor of Philosophy / Acoustic Frequency Domain Reflectometry (AFDR) is demonstrated as a novel method for using acoustic waves to sense different material parameters. Acoustic waves can be guided down various structures, such as a metal wire. Rather than sending out a short burst of acoustic power and analyzing its echoes in the metal wire, this technique uses a constant source of acoustic waves with varying frequency, instead recording how the electrical characteristics of the acoustic source change as frequency changes. Since the measurement is made across frequency, this method is particularly suited to correct for various aspects of the acoustic wave that change with frequency in an otherwise undesirable way. The ability to compensate for acoustic wave speeds that change with frequency as well as imperfections intrinsic to the tuning itself using multiple new methods is demonstrated. Distributed measurement of temperature is tested using various signal processing algorithms, and estimated to have a resolution of 0.58 °C for a 20 cm sensing length. The validated sensing system theoretically has the ability to resolve changes over 2 mm, and the resolution over which sensing may be possible is estimated to be 1 cm. AFDR and the associated signal processing developments are positioned to be transformative across many areas of acoustics, with significant potential for distributed sensing along an acoustic waveguide.

This study investigates the association between CEO severance agreements and corporate tax avoidance. Severance agreements, by providing executives with additional compensation when there is a change in employment status, should serve to encourage additional risk-taking, as reflected by increased tax avoidance activities. Using a large sample of aggregate compensation data, I find some evidence of a relation between the presence of a CEO severance agreement and tax avoidance. Using a smaller sample of hand-collected data, I find a significant negative relation between the magnitude of cash severance pay and tax avoidance and a significant positive relation between the magnitude of equity severance pay and tax avoidance. Overall, this study provides evidence that the structure and magnitude of severance agreements are related to tax avoidance. / Ph. D.

The National Collegiate Athletic Association (NCAA) has controlled intercollegiate sports for the past 150 years, but the passing of California Senate Bill 206 on September 30, 2019, placed that power at risk. The bill will allow student-athletes to receive compensation for their name, image and likeness in the state of California, and has influenced other states to bring forth legislation of their own. The NCAA announced on October 29, 2019, that it would change its policies and bylaws to allow student-athletes to profit from their name, image and likeness. This qualitative thematic analysis seeks to discover how the issue of student-athletes in the case of SB 206 was framed by the media before and after the bill was passed, and after the NCAA announced its policy change. From the analysis, three themes emerged to support student-athlete compensation, eight themes emerged in opposition, and 24 sub themes emerged for both sides. Anti-compensation framing strategies prevailed throughout news coverage before and after SB 206 passed, and after the NCAA changed its policy. Local and mainstream news outlets and sports and mainstream news outlets all presented the eight themes. / Master of Arts / The National Collegiate Athletic Association (NCAA) has controlled college sports for the past 150 years, but the passing of California Senate Bill 206 on September 30, 2019, placed that power at risk. The bill will allow student-athletes to receive compensation for their name, image and likeness in the state of California, and has influenced other states to bring forth legislation of their own. On October 29, 2019 the NCAA announced that it would change its policies and bylaws to allow student-athletes to profit from their name, image and likeness. This thesis uses a qualitative thematic analysis, meaning that news articles are examined by the researcher to understand common themes that emerge about how the issue of student-athlete in the case of SB 206 was portrayed by the media before and after the bill was passed, and after the NCAA changed its policy. From the analysis, three themes were found to support student-athlete compensation, eight themes were found in opposition, and 24 sub themes were found for both sides. Anti-compensation framing strategies dominated news coverage before and after SB 206 passed, and after the NCAA changed its policy even though the public opinion supported student-athlete compensation.

Additive manufacturing (AM) is a relatively new domain of manufacturing processes that began with its first patent in 1986. Since then, AM processes quickly grew in popularity due to their flexibility, superior efficiency in high mix low volume manufacturing settings, and lower material costs compared to more subtractive processes. Despite its increasing popularity, AM processes remain behind subtractive processes in terms of quality and the speed at which new technologies are integrated. Introducing Industry 4.0 technologies is an excellent opportunity to address the need for quality assurance tools for AM processes. First, the question of how the quality of additively manufactured parts can be increased to match parts created through subtractive processes must be asked. In this dissertation, two machine learning (ML) models are developed and utilized in a federated environment to mimic what one would see in a production setting. The proposed models increase AM part quality by (1) predicting the resulting geometry of an AM process and (2) compensating for geometric errors by altering the initial stereolithography (STL) file before slicing. In addition to performing geometric error prediction and compensation, the models were enhanced to be resilient to changes in geometry by training on segments of a 3D object rather than the whole object. Next, process parameters from fused-filament fabrication (FFF) processes were added to the ML models to add resilience process parameter variance. Lastly, the ML models were deployed in a federated environment created from three FFF 3D printers that collaboratively created a dataset for the ML models. Collectively, these works expand the research area created by AM, federated learning, and error compensation. This proposal addresses research gaps in the current literature by first setting the prediction and compensation resolution of voxel-based ML methods to a static 100 µm, thereby reducing the error associated with each voxel. Secondly, process parameters are introduced to the model, further increasing prediction and compensation accuracy compared to predicting on the geometry alone. Lastly, the models are deployed in a federated AM environment with multiple 3D printers acting as clients to reduce each client's time spent generating data while maintaining model performance. / Doctor of Philosophy / Additive manufacturing (AM) is a relatively new field where parts are created by extruding material to build a product in the desired shape. A key advantage of such a process is that it is more flexible than those subtractive processes, which remove material from a part. On the other hand, parts produced by AM processes generally have lower quality due to the very specific environments necessary to obtain high-quality parts. Because there is an increased desire to make customized parts (high mix) in small amounts (low volume), AM processes are seeing a rise in popularity, but there is still a need to improve the quality of these produced parts. Furthermore, these environments where AM is utilized generally have multiple 3D printers that manufacturers can leverage to create comprehensive datasets for model development. This dissertation uses machine learning (ML) to collect data from AM processes and reduce AM process errors. By comparing the process's input with the process's output, an ML model can estimate the result of the AM process, including potential defects. This dissertation addresses research gaps in current literature by reducing the error associated with converting the input and output 3D objects to voxels, using parameters to the AM process in the ML models, and using the ML models with 3D printers in a networked environment while forbidding sharing private data.

Increasing compensation disclosures mandated by the Securities Exchange Commission provide transparency that allows more shareholders to question the results produced by highly compensated executives. The popular business press often decries the apparent imbalance between executive pay and firm performance. Published academic research has responded with hundreds of studies attempting to explain executive pay in terms of firm performance. The preponderance of these studies focus on Chief Executive Officers. This study empirically examines executive compensation for team effects on future firm performance.Applying a firm specific fixed-effects model to a sample of 13,021 firm-year observations from ExecuComp, the current study regresses top management team compensation and control variables on firm performance averaged one, three, and five years following the year of compensation. One accounting based measure of performance (return on assets) and one market based measure of firm performance (shareholder return) is examined over the one three and five year horizons.Consistent with increasing concerns raised by investors regarding excess executive pay, this study finds evidence that higher top management team pay is associated with companies experiencing lower rates of return in the future. However, higher management team pay is associated with higher profits and market value measured in dollars. Theses effects are significantly different between the short-term and long term components of compensation. Although compensation of the team is highly correlated with the CEO, the compensation of the executive team has incremental effects on future firm performance of the company.This study contributes to the executive compensation literature by providing evidence that the compensation of the top management team affects future company performance. The observed impact of management team compensation on company performance is: incremental to CEO effects noted in prior studies, differential between short- and long-term components of compensation, sensitive to the proxy used for company performance, and attenuates over time. These findings suggest that further research on executive management team compensation is merited in order to address an interesting gap in the extant literature.