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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
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
Maternal cigarette smoking and marijuana use during pregnancy are risk factors that can adversely affect offspring. Although a large body of empirical literature has examined the adverse health effects of maternal cigarette smoking and marijuana use during pregnancy, few studies have looked at criminological factors associated with prenatal cigarette smoking and marijuana use. This thesis uses strain theory and social learning theory to explain a number of underlying mechanisms behind why some pregnant women decide to smoke tobacco and marijuana cigarettes during pregnancy. Previous drug involvement before pregnancy is also used to determine if it is a predictor of maternal cigarette smoking during pregnancy. Logistic regression was used to analyze data collected from the 1988 National Pregnancy and Infant Health Survey. This data set consists of information gathered from three different national samples of maternal and infant data occurring in 1988, which included 13,417 live births, 4,772 fetal deaths, and 8,166 infant deaths. The mothers in the sample were mailed questionnaires. Results showed that pregnant women who have unexpected pregnancies and experience financial hardship during pregnancy are more likely to smoke cigarettes and use marijuana during pregnancy, which is consistent with the general strain theory. Results also indicate that pregnant women who live in households with other people who smoke are more likely to smoke cigarettes during pregnancy, which may be explained by social learning, and that women who use illegal drugs are less likely to smoke cigarettes during pregnancy, even after controlling for strain and social learning. The practical and theoretical implications for this research are discussed.
ContributorsWhiteside, Alexandria (Author) / Ready, Justin (Thesis advisor) / Fox, Kathleen (Committee member) / Holtfreter, Kristy (Committee member) / Arizona State University (Publisher)
Created2014
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
General Strain Theory (GST) posits that different types of strain lead to different types of negative emotions, some of which increase the likelihood of maladaptive coping. Much research on GST has focused on anger and depression. Far less attention has been directed toward other negative emotions, including anxiety and envy. The current study uses cross-sectional data from surveys administered to a university-based sample (N = 500) to address these voids and explore gender differences in the effects of strain and negative emotions in maladaptive coping. Results indicate that when gender differences existed in levels of strain and negative emotions, females experienced higher levels than males. Strain significantly predicted all four measures of negative emotions examined in this study. Finally, different negative emotions were found to have differing effects on different measures of maladaptive coping. Implications of this study for theory, future research, and policy are discussed.
ContributorsZuniga, Ana Rosa (Author) / Holtfreter, Kristy (Thesis advisor) / Reisig, Michael (Committee member) / Wang, Xia (Committee member) / Arizona State University (Publisher)
Created2015
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
Description
The link between victimization and offending is well established in the literature, yet an unexplored causal pathway within this relationship is concerned with why some individuals engage in maladaptive coping in response to victimization. In particular, those with low self-control may be attracted to problematic yet immediately gratifying forms of coping post-victimization (e.g., substance use), which may increase their likelihood of violent offending in the future. Using three waves of adolescent panel data from the Gang Resistance Education and Training (GREAT) program, this research examines: (1) whether individuals with low-self control are more likely to engage in substance use coping following violent victimization, and (2) whether victims with low self-control who engage in substance use coping are more likely to commit violent offenses in the future. The results from negative binomial regressions support these hypotheses, even after controlling for prior offending, peer influences, prior substance abuse, and other forms of offending. The implications for integrating general strain and self-control theories, as well as for our understanding of the victimization-offending overlap, are discussed.
ContributorsTuranovic, Jillian (Author) / Pratt, Travis C. (Thesis advisor) / Reisig, Michael D (Committee member) / Fornango, Robert J (Committee member) / Arizona State University (Publisher)
Created2011
Description
Academic deviance is a potentially detrimental behavior for students and universities alike in that it causes credit to be given to individuals where it is not due. Furthermore, it is a common occurrence, with around half of college students admitting to engaging in this behavior at least once. Therefore, the purpose of this study is to investigate the relationship between perfectionism, strain, and academic deviance. In doing this, this study uses data from a primary data collection effort in Arizona State University, with a final sample of 696 students, to answer three research questions: Are there differences in the likelihood of engaging in academic deviance by maladaptive perfectionists, adaptive perfectionists, and non-perfectionists? Are there differences in the perceptions of the wrongness of academic deviance between maladaptive perfectionists, adaptive perfectionists, and non-perfectionists? Are there differences in how context dependent maladaptive perfectionists, adaptive perfectionists, and non-perfectionists view academic deviance the wrongness of academic deviance? Ordered logistic regression are used to access these research questions. Results suggest that neither perfectionism nor strain were a significant factor in determining the likelihood that a participant would engage in an academically deviant behavior, or how wrong they believed that behavior to be. However, perfectionism did seem to have a mild impact on how context dependent individuals felt the wrongness of their behaviors, meaning that if the cause of the strain was due to the professor’s actions, students viewed academic deviance as less wrong, and self-control explained at least part of this effect. Strain, on the other hand, did not have a significant effect. Overall, the results suggest some legitimacy to the use of general strain theory to explain the potential relationships, given the relationship between perfectionism and context dependency. Additionally, the results support policy implications designed to reduce maladaptive thoughts and subsequently academic deviance, such as cognitive behavioral therapy (CBT). Future research should examine the link between perfectionism and other types of academic strain.
ContributorsAllen, Savanna Marie (Author) / Pizarro, Jesenia (Thesis advisor) / Fine, Adam (Committee member) / Young, Jacob (Committee member) / Arizona State University (Publisher)
Created2020
Description
This study tested hypotheses derived from general strain theory, including whether the disposition for crime (e.g., trait anger and low self-control) and prosocial
coping moderate the link between state-based negative emotions and maladaptive coping.
A 2x2 factorial vignette was embedded in a survey instrument and administered to a
university-based sample (N = 503). The results from the regression models support
different parts of general strain theory, such as the direct effect of strain on negative
emotions, the effect of negative emotions on aggressive coping, and the mediating effect
of negative emotions. Finally, the effect of some negative emotions on aggressive coping
were moderated by trait anger, low self-control, and prosocial coping. The findings of
this study support the argument that dispositions to maladaptive coping amplify the
effects of negative emotion and underscore the importance of establishing prosocial
coping resources.
Keywords: emotions, general strain theory, low self-control, maladaptive coping
ContributorsWood, Margaret Tynan (Author) / Reisig, Michael D. (Thesis advisor) / Young, Jacob T.N. (Committee member) / Telep, Cody W. (Committee member) / Arizona State University (Publisher)
Created2023