Matching Items (168)
Description
In this thesis I introduce a new direction to computing using nonlinear chaotic dynamics. The main idea is rich dynamics of a chaotic system enables us to (1) build better computers that have a flexible instruction set, and (2) carry out computation that conventional computers are not good at it. Here I start from the theory, explaining how one can build a computing logic block using a chaotic system, and then I introduce a new theoretical analysis for chaos computing. Specifically, I demonstrate how unstable periodic orbits and a model based on them explains and predicts how and how well a chaotic system can do computation. Furthermore, since unstable periodic orbits and their stability measures in terms of eigenvalues are extractable from experimental times series, I develop a time series technique for modeling and predicting chaos computing from a given time series of a chaotic system. After building a theoretical framework for chaos computing I proceed to architecture of these chaos-computing blocks to build a sophisticated computing system out of them. I describe how one can arrange and organize these chaos-based blocks to build a computer. I propose a brand new computer architecture using chaos computing, which shifts the limits of conventional computers by introducing flexible instruction set. Our new chaos based computer has a flexible instruction set, meaning that the user can load its desired instruction set to the computer to reconfigure the computer to be an implementation for the desired instruction set. Apart from direct application of chaos theory in generic computation, the application of chaos theory to speech processing is explained and a novel application for chaos theory in speech coding and synthesizing is introduced. More specifically it is demonstrated how a chaotic system can model the natural turbulent flow of the air in the human speech production system and how chaotic orbits can be used to excite a vocal tract model. Also as another approach to build computing system based on nonlinear system, the idea of Logical Stochastic Resonance is studied and adapted to an autoregulatory gene network in the bacteriophage λ.
ContributorsKia, Behnam (Author) / Ditto, William (Thesis advisor) / Huang, Liang (Committee member) / Lai, Ying-Cheng (Committee member) / Helms Tillery, Stephen (Committee member) / Arizona State University (Publisher)
Created2011
Description
This dissertation explores the lives of women who are on the Severely Mentally Ill (SMI) caseload at Maricopa County Adult Probation in Arizona (The Phoenix metro region). The project focuses on three primary issues: (1) what are the pathways to the criminal justice and mental health systems for women on the SMI caseload (2) how does discretion and expansive formal social control (both benevolent and coercive) impact the lives of these women on the SMI caseload and (3) what are the gendered aspects to successful completion of SMI probation. To answer these questions a mixed-methods research design was employed. First, in-depth semi-structured interviews were completed with 65 women on the SMI caseload. Second, these interviews were supplemented with a case file review of each participant, and field observations (encompassing roughly 100 hours) were conducted at the Maricopa County Mental Health Court. Third, analysis also included 5.5 years of quantitative intake data from the SMI caseload, exploring demographic information and risk and assessment needs scores. The biographies of the women on the SMI caseload revealed similar histories of victimization, substance abuse, and relationship difficulty that previous pathways research has noted. Additionally, mental health problems directly impacted the path to the criminal justice system for some women on the SMI caseload. Results also showed many aspects of expanded social control for women on the SMI caseload. This expanded control appeared to be gendered at times and often created double binds for women. Finally, quantitative analysis showed that some predictive factors of SMI probation completion were gendered. Policy implications and summaries of findings are discussed.
ContributorsMulvey, Philip (Author) / Decker, Scott H. (Thesis advisor) / Spohn, Cassia (Committee member) / Holtfreter, Kristy (Committee member) / Arizona State University (Publisher)
Created2013
Description
The study of non-U.S. citizens in criminal justice system outcomes has often been neglected in the sentencing literature. When citizenship is considered, there are generally no distinctions made within this group. The research fails to consider differences according to legal status, race/ethnicity, nationality and other distinctive markers that might play a role in sentencing outcomes. Using federal sentencing data collected by the United States Sentencing Commission for fiscal year 2006 through fiscal year 2008, this study examines the effect of offender citizenship status, legal status, and national origin on the likelihood of imprisonment and length of imprisonment for offenders convicted of drug offenses. The current study considers differences among foreign-born and Latino immigrant subgroups (e.g., Colombian, Cuban, Dominican, and Mexican nationals). The key findings in this dissertation include: (1) non-U.S. citizens have greater odds of imprisonment than U.S. citizens. However, non-U.S. citizen offenders receive significantly shorter prison terms relative to U.S. citizen offenders; (2) undocumented immigrants are more likely to be incarcerated compared to similarly situated authorized immigrants and U.S. citizens. However, legal status does not have an effect on sentence length; and (3) with respect to national origin, Mexican nationals are significantly more likely than Colombians to be incarcerated and are given significantly longer prison sentences than Dominican nationals. The implications of these findings and future research are addressed in the concluding chapter.
ContributorsValadez, Mercedes (Author) / Spohn, Cassia (Thesis advisor) / Wang, Xia (Committee member) / Wright, Kevin (Committee member) / Arizona State University (Publisher)
Created2013
Description
Criminologists have directed significant theoretical and empirical attention toward the institution of marriage over the past two decades. Importantly, the momentum guiding this line of research has increased despite the fact that people are getting married far less often and much later in the life course than in any point in American history. The aim of this dissertation is to address this disconnect by focusing attention to nonmarital romantic relationships and their instability during emerging adulthood. To do so, it uses data from the Pathways to Desistance Study, a longitudinal study of 1,354 at-risk males and females who were adjudicated from the juvenile and adult systems in Phoenix and Philadelphia between 2000 and 2003. The project focuses attention to the following issues: (1) the effect of romantic dissolution on aggressive and income-based offenses; (2) the extent to which strain
egative emotionality and peer influence/exposure account for the effect of romantic dissolution on crime; and (3) the extent to which certain relationship and individual circumstances moderate the effect of romantic dissolution. The models reveal a few key findings. First, romantic dissolution is strongly related to an increase in both aggressive and income-based crime, but is more strongly related to income-based crime. Second, the effect of romantic dissolution is reduced when measures of strain
egative emotionality and peer influence/exposure measures are added to models, but the peer influence/exposure measures account for the strongest reduction. Finally, romantic dissolution does not serve as a positive life event among these at-risk youth, but its effect is exacerbated under a number of contexts (e.g. when an individual is unemployed). This study closes with a summary of these findings as well as its key limitations, and offers insight into potential policy implications and avenues of future research.
egative emotionality and peer influence/exposure account for the effect of romantic dissolution on crime; and (3) the extent to which certain relationship and individual circumstances moderate the effect of romantic dissolution. The models reveal a few key findings. First, romantic dissolution is strongly related to an increase in both aggressive and income-based crime, but is more strongly related to income-based crime. Second, the effect of romantic dissolution is reduced when measures of strain
egative emotionality and peer influence/exposure measures are added to models, but the peer influence/exposure measures account for the strongest reduction. Finally, romantic dissolution does not serve as a positive life event among these at-risk youth, but its effect is exacerbated under a number of contexts (e.g. when an individual is unemployed). This study closes with a summary of these findings as well as its key limitations, and offers insight into potential policy implications and avenues of future research.
ContributorsLarson, Matthew Joseph (Author) / Sweeten, Gary (Thesis advisor) / Piquero, Alex (Committee member) / Spohn, Cassia (Committee member) / Wallace, Danielle (Committee member) / Arizona State University (Publisher)
Created2013
Description
The purpose of this project is to better understand the factors associated with, and effects of, prison visitation for children during maternal and paternal incarceration. As gatekeepers, caregivers play a pivotal role in the facilitation of parent-child prison visitation. Yet, some caregivers may be more likely to take children to visit than others. Additionally, among those children who do visit, visitation may be positive in some ways and negative in others. To advance prior work, this study (1) assesses the relationship between caregiver type and parent-child prison visitation and (2) investigates the emotional and behavioral responses of children who visit. The current research uses mixed-methods and is carried out in two phases. For Phase 1, quantitative data on 984 children collected from structured interviews with incarcerated parents (N=279 mothers; N=143 fathers) in the Arizona Department of Corrections are used to examine the relationship between caregiver type and the likelihood of parent-child prison visitation. Descriptive statistics and logistic regression analyses are conducted separately for maternal and paternal incarceration. Phase 2 draws on caregivers' accounts of 40 children who visit their parent in prison to assess children's emotional and behavioral reactions to visitation. Data are coded to identify positive and negative responses, "visitation paradox" indicators, prior life circumstances and child age. Thematic content analyses are conducted to capture major themes. Analyses from Phase 1 confirm a significant relationship between caregiver type and mother-child and father-child visitation. Other factors that affected the likelihood of parental visitation included child situational factors, parent stressors, institutional barriers and child demographics, although these effects differed depending upon which parent was in prison. Results from Phase 2 revealed overwhelmingly negative responses among children to parental prison visitation. Key themes that accounted for child reactions included institutional context and parental attachment. This research adds to the collateral consequences of incarceration literature by providing greater insight into the imprisonment experience for vulnerable families. Further, these results have direct implications for correctional policy and practice pertaining to the manner and regulation of prison visits and also inform reentry efforts through a family-centric approach.
ContributorsTasca, Melinda (Author) / Rodriguez, Nancy (Thesis advisor) / Spohn, Cassia (Committee member) / Zatz, Marjorie S (Committee member) / Arizona State University (Publisher)
Created2014
Description
The purpose of this preliminary study is to determine if sentencing disparities exist between male and female teachers who have been convicted of sexual misconduct with a student in Maricopa County, Arizona over a ten-year period. The hypothesis is that male teachers convicted of sexual misconduct with a student will receive harsher punishment than their female counterparts. In addition, this research will analyze the sentencing decisions of Arizona judges and prosecutors through plea-bargaining when compared with the presumptive sentence set by the Arizona Legislature. Issues that will be addressed include: a brief review of gender disparities in sentencing, sex offender sentencing, Arizona's rules of criminal procedure, and a review of the Arizona Revised Statutes pertaining to sexual crimes as well as the Arizona Supreme Court sentencing guidelines. The data set consists of fifteen different Maricopa County teachers who committed a sexual offense against a student and were convicted of that offense from February 2000 through September 2009. According to the results of this study, male teachers do receive harsher penalties than their female counterparts within Maricopa County.
ContributorsSimmon, Christopher (Author) / Holtfreter, Kristy (Thesis advisor) / Wright, Kevin (Committee member) / Spohn, Cassia (Committee member) / Arizona State University (Publisher)
Created2012
Description
Contemporary criminological literature seldom studies important ethnic subgroup differences in crime and delinquency among Hispanic/Latino youth. Therefore, their risk for crime and delinquency is poorly understood in light of the enormous ethnic and generational mixture experiences within of experiences within the Hispanic/Latino population in the United States. Using social control theory and cultural evaluations of familism, this thesis examines dissimilarities in the risk for crime and delinquency, in addition to its relations with family unity, parental engagement, youth independence, and family structure among second generation Mexicans (n = 876) and second generation Cubans (n = 525) using data from the Children of Immigrants Longitudinal Study (CILS) 1991-2006 (Portes and Rumbaut). The results concluded that second generation Cubans who obtained government assistance were more likely to engage in crime than second generation Mexicans. Consistent with social control theory, a major finding in this thesis is that presence of a family member who is involved in criminal activity increased crime within the sample of second generation Mexicans and second generation Cubans. Furthermore, in households less than five, second generation Cubans who have a delinquent family member were more likely than second generation Mexicans who have a delinquent family member to report criminal involvement, while in households greater than five, second generation Mexicans who have a delinquent family member were more likely than second generation Cubans who have a delinquent family member to report criminal involvement.
ContributorsOrtiz, Raul G (Author) / Spohn, Cassia (Thesis advisor) / Rodriguez, Nancy (Committee member) / Ready, Justin (Committee member) / Arizona State University (Publisher)
Created2012
Description
Complex dynamical systems consisting interacting dynamical units are ubiquitous in nature and society. Predicting and reconstructing nonlinear dynamics of units and the complex interacting networks among them serves the base for the understanding of a variety of collective dynamical phenomena. I present a general method to address the two outstanding problems as a whole based solely on time-series measurements. The method is implemented by incorporating compressive sensing approach that enables an accurate reconstruction of complex dynamical systems in terms of both nodal equations that determines the self-dynamics of units and detailed coupling patterns among units. The representative advantages of the approach are (i) the sparse data requirement which allows for a successful reconstruction from limited measurements, and (ii) general applicability to identical and nonidentical nodal dynamics, and to networks with arbitrary interacting structure, strength and sizes. Another two challenging problem of significant interest in nonlinear dynamics: (i) predicting catastrophes in nonlinear dynamical systems in advance of their occurrences and (ii) predicting the future state for time-varying nonlinear dynamical systems, can be formulated and solved in the framework of compressive sensing using only limited measurements. Once the network structure can be inferred, the dynamics behavior on them can be investigated, for example optimize information spreading dynamics, suppress cascading dynamics and traffic congestion, enhance synchronization, game dynamics, etc. The results can yield insights to control strategies design in the real-world social and natural systems. Since 2004, there has been a tremendous amount of interest in graphene. The most amazing feature of graphene is that there exists linear energy-momentum relationship when energy is low. The quasi-particles inside the system can be treated as chiral, massless Dirac fermions obeying relativistic quantum mechanics. Therefore, the graphene provides one perfect test bed to investigate relativistic quantum phenomena, such as relativistic quantum chaotic scattering and abnormal electron paths induced by klein tunneling. This phenomenon has profound implications to the development of graphene based devices that require stable electronic properties.
ContributorsYang, Rui (Author) / Lai, Ying-Cheng (Thesis advisor) / Duman, Tolga M. (Committee member) / Akis, Richard (Committee member) / Huang, Liang (Committee member) / Arizona State University (Publisher)
Created2012
Description
What can classical chaos do to quantum systems is a fundamental issue highly relevant to a number of branches in physics. The field of quantum chaos has been active for three decades, where the focus was on non-relativistic quantumsystems described by the Schr¨odinger equation. By developing an efficient method to solve the Dirac equation in the setting where relativistic particles can tunnel between two symmetric cavities through a potential barrier, chaotic cavities are found to suppress the spread in the tunneling rate. Tunneling rate for any given energy assumes a wide range that increases with the energy for integrable classical dynamics. However, for chaotic underlying dynamics, the spread is greatly reduced. A remarkable feature, which is a consequence of Klein tunneling, arise only in relativistc quantum systems that substantial tunneling exists even for particle energy approaching zero. Similar results are found in graphene tunneling devices, implying high relevance of relativistic quantum chaos to the development of such devices. Wave propagation through random media occurs in many physical systems, where interesting phenomena such as branched, fracal-like wave patterns can arise. The generic origin of these wave structures is currently a matter of active debate. It is of fundamental interest to develop a minimal, paradigmaticmodel that can generate robust branched wave structures. In so doing, a general observation in all situations where branched structures emerge is non-Gaussian statistics of wave intensity with an algebraic tail in the probability density function. Thus, a universal algebraic wave-intensity distribution becomes the criterion for the validity of any minimal model of branched wave patterns. Coexistence of competing species in spatially extended ecosystems is key to biodiversity in nature. Understanding the dynamical mechanisms of coexistence is a fundamental problem of continuous interest not only in evolutionary biology but also in nonlinear science. A continuous model is proposed for cyclically competing species and the effect of the interplay between the interaction range and mobility on coexistence is investigated. A transition from coexistence to extinction is uncovered with a non-monotonic behavior in the coexistence probability and switches between spiral and plane-wave patterns arise. Strong mobility can either promote or hamper coexistence, while absent in lattice-based models, can be explained in terms of nonlinear partial differential equations.
ContributorsNi, Xuan (Author) / Lai, Ying-Cheng (Thesis advisor) / Huang, Liang (Committee member) / Yu, Hongbin (Committee member) / Akis, Richard (Committee member) / Arizona State University (Publisher)
Created2012
Description
The purpose of this study is to first investigate the role of political socialization on young men and women and what motivates them to become politically active and make the ultimate decision to run for elected office. These effects include parental attitudes, exposure to political shows and news sources, participation in voluntary organizations, and overall community involvement. After understanding these direct and indirect effects of political socialization, I can attempt to explain the causes for the gender gap in political ambition \u2014 meaning that significantly more men are running for elected office compared to women.
ContributorsOsgood, Shannon Marie (Author) / Woodall, Gina (Thesis director) / Herrera, Richard (Committee member) / Barrett, The Honors College (Contributor) / College of Public Service and Community Solutions (Contributor) / School of Public Affairs (Contributor) / School of Politics and Global Studies (Contributor)
Created2015-05