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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
The link between childhood neuropsychological deficits and early-onset offending--the assumed precursor to life-course persistent offending--has been well established, yet the underlying mechanisms facilitating this relationship are less understood. Support is growing for the claim that self-control is a key mechanism that links neuropsychological deficits to early-onset offending. Despite this, findings are mixed with regard to the mediating effect of self-control in the relationship between neuropsychological deficits and antisocial behavior. These studies largely support the notion that self-control exerts a mediating effect on neuropsychological deficits when the offending being studied is less serious. Using data from the National Longitudinal Survey of Youth (NLSY), the present study seeks to build upon the existing literature by examining whether self-control mediates the relationship between neuropsychological deficits and two types of early-onset offending--low and high risk--as a means of testing core tenets of Gottfredson and Hirschi's (1990) and Moffitt's (1993) criminological theories. Findings show that while self-control and neuropsychological deficits independently predict general early-onset offending, these effects vary as a consequence of early-onset offender type. The results point to the need for future research to explore the possibility that the early-onset offender group that leads to persistent offending could be more precisely defined. Examining early-onset offending as a single construct limits our ability to make inferences about those offenders that are the most persistent in their offending patterns and, arguably, more likely to continue offending over the life-course.
ContributorsInfante, Arynn (Author) / Burt, Callie H (Thesis advisor) / Decker, Scott (Committee member) / Young, Jacob Tn (Committee member) / Arizona State University (Publisher)
Created2014
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
Juvenile delinquency is a complex issue that effects youth, families, and society. Studies have found that parenting styles are a significant contributor to numerous behaviors that influence juvenile delinquency, specifically substance use and poor academic achievement. This literature has been used by to the juvenile justice system to develop family based interventions for delinquent youth in efforts to reduce recidivism. However, previous studies have primarily sampled from the general population, which has limited their usefulness in creating selective interventions for the delinquent population. This thesis offers Baumrind (1966) and Maccoby & Martin's (1983) theory of parenting style typologies as a framework for understanding the effects of parenting style on substance use and academic achievement among delinquent youth. Using juvenile court case files from Maricopa County collected from 2005-2010, (N = 181), logistic regression was performed to test the hypotheses that (1) delinquent youth with Authoritarian, Uninvolved, and Permissive parenting will be more likely to use substances than youth with Authoritative parenting and that (2) delinquent youth with Authoritarian, Uninvolved, and Permissive parenting will be more likely to have poor academic achievement than youth with Authoritative parenting. Using Authoritative parenting as the reference group, it was found that delinquent youth with Permissive and Uninvolved parenting had a higher likelihood of substance use than delinquent youth with Authoritative parenting, and that delinquent youth with Permissive parenting had a higher likelihood of poor academic achievement than youth with Authoritative parenting. These findings have important theoretical implications as well as practical implications for intervention strategies for delinquent youth, which are additionally discussed.
ContributorsPosey, Brianne M (Author) / Rodriguez, Nancy (Thesis advisor) / Burt, Callie (Committee member) / Zatz, Marjorie (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
The research on female juvenile gang members is limited in scope and research has not yet examined mental health issues in this population. This study examines the case histories of 127 female juvenile gang members who were arrested by the Florida Department of Juvenile Justice. To add to the limited gender-specific research on female juvenile gang members, data are presented regarding this population's mental health problems, childhood maltreatment, substance abuse problems, age of contact with the juvenile justice system, and other factors salient to female juvenile gang members' prevention, treatment, and intervention needs. Female juvenile gang members who had a mental health diagnosis were significantly more likely to report childhood maltreatment. Female juvenile gang members who were younger at their age of first arrest were significantly more likely to report chronic substance use. Clinical levels of anger-irritability and depression-anxiety were found for approximately half of female juvenile gang members and suicide ideation was found for approximately one fourth. These findings have important implications for practitioners and gender-specific prevention, intervention, and treatment programs targeted specifically for female juvenile gang members.
ContributorsDowning, Leigh Anne (Author) / Roe-Sepowitz, Dominique (Thesis advisor) / Anthony, Elizabeth (Committee member) / Jackson, Kelly (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