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- Genre: Masters Thesis
- Creators: Arizona State University
- Creators: Chakraborty, Bijeta
- Creators: Peterson, Cory
- Member of: ASU Electronic Theses and Dissertations
Description
This descriptive research study explored practicing Board-Certified Music Therapists' engagement in self-care as needed from the impact of stress and burnout, as well as perceptions of the music therapy profession and professional association. An online survey was completed by 829 practicing board certified music therapists. Mean scores and percentages of nominal variables were generated from an independent sample. ANOVA was used to compare mean scores of dependent variables with independent variables of two or more categories. Open-ended responses generated extensive qualitative data about stress/burnout, job satisfaction, motivation, and self-care. Those who are not currently members of AMTA reported affordability as the primary reason for not being members. Despite some negative perceptions about the profession and professional association, a significant number of music therapists expressed a passion for what they do. Music therapists appear to have a solid grasp on professional responsibilities and ethics. Although respondents reported an overall high level of job satisfaction, a substantial number agreed that they have considered leaving the profession. Low salary was the most commonly acknowledged reason, followed by the continued need to "sell" music therapy, burnout, stress, limited work opportunities, and workplace politics. Respondents identified healthy diet and rest as primary activities of self-care, followed by recreation/leisure time with loved ones, exercise, hobbies, and prayer. Music therapists reportedly continue to feel motivated and inspired in the profession predominantly because of the gratification/satisfaction of the results of their work, followed by engagement in self-care, loving the work regardless of income, attending conferences and symposiums, diversification among various populations, and keeping professional life separate from personal life. ANOVA results indicated that job satisfaction and engagement in self-care likely increase with age; job satisfaction is higher among married music therapists, those with children, and those with more than 30 years in practice; and those with no children and those with a master's or doctorate degree were more likely to engage in self-care. A variety of implications and recommendations are explored.
ContributorsMurillo, Julie Hoffer (Author) / Crowe, Barbara J. (Thesis advisor) / Rio, Robin (Committee member) / Tobias, Evan (Committee member) / Arizona State University (Publisher)
Created2013
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
Over the past several years, engagement and embeddedness have become popular research topics for academics and practitioners alike. Research has demonstrated associations between these constructs and a variety of predictors and outcomes. Prior research has not, however, placed enough emphasis on the roles of employee type, industry type, and work setting in determining predictors and outcomes. Additionally, the relative roles of engagement and embeddedness in predicting outcomes have not been thoroughly investigated. This study investigated the predictors and outcomes of engagement and embeddedness among unskilled, production line employees working in food processing in the agricultural industry by conducting a survey of employees and their supervisors. Employees answered questions about personality, motivation, satisfaction, engagement, and embeddedness while supervisors answered questions about each employee's performance. Results suggest that both engagement and embeddedness predict employee satisfaction and that engagement does so more strongly, both of which support prior research. However, results contradict prior research by suggesting that embeddedness is strongly predicted by traits internal to the employee while engagement is not, and neither engagement nor embeddedness significantly predicts employee performance. Further, the findings suggest that employees working in different settings and industries may experience work differently, and the measurements used to understand their experiences should reflect these differences.
ContributorsBryan, Kathleen (Author) / Newman, Matthew L. (Thesis advisor) / Hall, Deborah L. (Committee member) / Schweitzer, Nick (Committee member) / Arizona State University (Publisher)
Created2012
Description
The objective of this study was to understand domestic and foreign-born housekeeper's individual perceptions of labor mobility and job satisfaction related to their jobs within the hospitality industry. Literature regarding the bridging of tourism, immigration, and labor supply was addressed to expose broad conceptual frameworks that lead to the development of this study. More specifically, literature regarding labor mobility within tourism industries, migrant decision making, and barriers to mobility and immigration helped to construct a narrowed conceptual framework specific to hospitality labor in Phoenix, Arizona. Similar and previous studies focused on perceived labor mobility during significant economic or industry shifts. This study included the addition of a policy factor to help determine to what degree state policy change effected hospitality workers' perceived labor mobility. Arizona's recently passed and implemented legislative act SB1070 regards immigrant identification and employment, and enforcement of the act in the state of Arizona; this serves as the implicated policy change. Data were collected via on-site survey administered February to May 2011. An overall score was created for the five motivational dimensions: 1 — Status; 2 — Economic; 3 — Refugee; 4 — Entrepreneurial; and, 5 — Political using principle component factor analysis using a varimax rotation with Kaiser normalization. Theory and literature suggest that the economic advancement, status advancement, and the refugee orientation are effective explanatory variables for motivating a career move into the tourism industry. A total of 82 questionnaires were delivered and completed (N = 82), and none were eliminated. The statistically-determined Economic Dimension was characterized by eleven statements explained 51% of the variation and was the overwhelming motivational force. The average coded response for change in job satisfaction was very positive at .75. Ten features of changes in job satisfaction were used as the basis of the second measure of change in job satisfaction. The first Principle Component of the ten features of job satisfaction change explained 45% of the variation in these features and loadings were positive near or above 0.60 for all items. The relationship between variations in each of the measurements of change in job satisfaction and motivating factors was explored using regression analysis. The two dependent variables were Overall Change and First Principle Component, and the independent variables for both regressions included the four motivating factors as measured by the rotated factors scores to represent dimensions of Economic, Status, Refugee and Entrepreneurial. In addition to the motivational factors, four demographic variables were included as independent variables to account for personal and situational differences. None of the regression coefficients were significant at even the 10% level. Although this result was expected, the positive sign of regression coefficients suggest that expectations of working as a housekeepers results in a positive outcome. Understanding this relationship further is necessary, and seeking larger sample sizes over a longer period of time would be most beneficial to this field of research.
ContributorsCasson, Mallory (Author) / Tyrrell, Timothy (Thesis advisor) / Budruk, Megha (Committee member) / Li, Wei (Committee member) / Arizona State University (Publisher)
Created2011
Description
Class D Amplifiers are widely used in portable systems such as mobile phones to achieve high efficiency. The demands of portable electronics for low power consumption to extend battery life and reduce heat dissipation mandate efficient, high-performance audio amplifiers. The high efficiency of Class D amplifiers (CDAs) makes them particularly attractive for portable applications. The Digital class D amplifier is an interesting solution to increase the efficiency of embedded systems. However, this solution is not good enough in terms of PWM stage linearity and power supply rejection. An efficient control is needed to correct the error sources in order to get a high fidelity sound quality in the whole audio range of frequencies. A fundamental analysis on various error sources due to non idealities in the power stage have been discussed here with key focus on Power supply perturbations driving the Power stage of a Class D Audio Amplifier. Two types of closed loop Digital Class D architecture for PSRR improvement have been proposed and modeled. Double sided uniform sampling modulation has been used. One of the architecture uses feedback around the power stage and the second architecture uses feedback into digital domain. Simulation & experimental results confirm that the closed loop PSRR & PS-IMD improve by around 30-40 dB and 25 dB respectively.
ContributorsChakraborty, Bijeta (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
In this thesis, a digital input class D audio amplifier system which has the ability
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
ContributorsBai, Jing (Author) / Bakkaloglu, Bertan (Thesis advisor) / Arizona State University (Publisher)
Created2015