Principal component and second generation wavelet analysis of Treasury yield curve evolution

Prices of U.S. Treasury securities vary over time and across maturities. When the market in Treasurys is sufficiently complete and frictionless, these prices may be modeled by a function time and maturity. A cross-section of this function for time held fixed is called the yield curve; the aggregate of these sections is the evolution of the yield curve. This dissertation studies aspects of this evolution. ^ There are two complementary approaches to the study of yield curve evolution here. The first is principal components analysis; the second is wavelet analysis. In both approaches both the time and maturity variables are discretized. In principal components analysis the vectors of yield curve shifts are viewed as observations of a multivariate normal distribution. The resulting covariance matrix is diagonalized; the resulting eigenvalues and eigenvectors (the principal components) are used to draw inferences about the yield curve evolution. ^ In wavelet analysis, the vectors of shifts are resolved into hierarchies of localized fundamental shifts (wavelets) that leave specified global properties invariant (average change and duration change). The hierarchies relate to the degree of localization with movements restricted to a single maturity at the base and general movements at the apex. Second generation wavelet techniques allow better adaptation of the model to economic observables. Statistically, the wavelet approach is inherently nonparametric while the wavelets themselves are better adapted to describing a complete market. ^ Principal components analysis provides information on the dimension of the yield curve process. While there is no clear demarkation between operative factors and noise, the top six principal components pick up 99% of total interest rate variation 95% of the time. An economically justified basis of this process is hard to find; for example a simple linear model will not suffice for the first principal component and the shape of this component is nonstationary. ^ Wavelet analysis works more directly with yield curve observations than principal components analysis. In fact the complete process from bond data to multiresolution is presented, including the dedicated Perl programs and the details of the portfolio metrics and specially adapted wavelet construction. The result is more robust statistics which provide balance to the more fragile principal components analysis. ^

Spatial-temporal mining of archived automatic vehicle location (AVL) data for transit service planning applications

An Automatic Vehicle Location (AVL) system is a computer-based vehicle tracking system that is capable of determining a vehicle's location in real time. As a major technology of the Advanced Public Transportation System (APTS), AVL systems have been widely deployed by transit agencies for purposes such as real-time operation monitoring, computer-aided dispatching, and arrival time prediction. AVL systems make a large amount of transit performance data available that are valuable for transit performance management and planning purposes. However, the difficulties of extracting useful information from the huge spatial-temporal database have hindered off-line applications of the AVL data. ^ In this study, a data mining process, including data integration, cluster analysis, and multiple regression, is proposed. The AVL-generated data are first integrated into a Geographic Information System (GIS) platform. The model-based cluster method is employed to investigate the spatial and temporal patterns of transit travel speeds, which may be easily translated into travel time. The transit speed variations along the route segments are identified. Transit service periods such as morning peak, mid-day, afternoon peak, and evening periods are determined based on analyses of transit travel speed variations for different times of day. The seasonal patterns of transit performance are investigated by using the analysis of variance (ANOVA). Travel speed models based on the clustered time-of-day intervals are developed using important factors identified as having significant effects on speed for different time-of-day periods. ^ It has been found that transit performance varied from different seasons and different time-of-day periods. The geographic location of a transit route segment also plays a role in the variation of the transit performance. The results of this research indicate that advanced data mining techniques have good potential in providing automated techniques of assisting transit agencies in service planning, scheduling, and operations control. ^

Toward a unified theory of task -oriented and relationship -oriented leader behavior: A multi -country generalizability study

The theoretical foundation of this study comes from the significant recurrence throughout the leadership literature of two distinct behaviors, task orientation and relationship orientation. Task orientation and relationship orientation are assumed to be generic behaviors, which are universally observed and applied in organizations, even though they may be uniquely enacted in organizations across cultures. The lack of empirical evidence supporting these assumptions provided the impetus to hypothetically develop and empirically confirm the universal application of task orientation and relationship orientation and the generalizability of their measurement in a cross-cultural setting. Task orientation and relationship orientation are operationalized through consideration and initiation of structure, two well-established theoretical leadership constructs. Multiple-group mean and covariance structures (MACS) analyses are used to simultaneously validate the generalizability of the two hypothesized constructs across the 12 cultural groups and to assess whether the similarities and differences discovered are measurement and scaling artifacts or reflect true cross-cultural differences. The data were collected by the author and others as part of a larger international research project. The data are comprised of 2341 managers from 12 countries/regions. The results provide compelling evidence that task orientation and relationship orientation, reliably and validly operationalized through consideration and initiation of structure, are generalizable across the countries/regions sampled. But the results also reveal significant differences in the perception of these behaviors, suggesting that some aspects of task orientation and relationship orientation are strongly affected by cultural influences. These (similarities and) differences reflect directly interpretable, error-free effects among the constructs at the behavioral level. Thus, task orientation and relationship orientation can demonstrate different relations among cultures, yet still be defined equivalently across the 11 cultures studied. The differences found in this study are true differences and may contain information about cultural influences characterizing each cultural context (i.e. group). The nature of such influences should be examined before the results can be meaningfully interpreted. To examine the effects of cultural characteristics on the constructs, additional hypotheses on the constructs' latent parameters can be tested across groups. Construct-level tests are illustrated in hypothetical examples in light of the study's results. The study contributes significantly to the theoretical understanding of the nature and generalizability of psychological constructs. The theoretical and practical implications of embedding context into a unified theory of task orientated and relationship oriented leader behavior are proposed. Limitations and contributions are also discussed. ^

A reliability centered maintenance decision system for a discrete part manufacturing facility

This thesis develops and validates the framework of a specialized maintenance decision support system for a discrete part manufacturing facility. Its construction utilizes a modular approach based on the fundamental philosophy of Reliability Centered Maintenance (RCM). The proposed architecture uniquely integrates System Decomposition, System Evaluation, Failure Analysis, Logic Tree Analysis, and Maintenance Planning modules. It presents an ideal solution to the unique maintenance inadequacies of modern discrete part manufacturing systems. Well established techniques are incorporated as building blocks of the system's modules. These include Failure Mode Effect and Criticality Analysis (FMECA), Logic Tree Analysis (LTA), Theory of Constraints (TOC), and an Expert System (ES). A Maintenance Information System (MIS) performs the system's support functions. Validation was performed by field testing of the system at a Miami based manufacturing facility. Such a maintenance support system potentially reduces downtime losses and contributes to higher product quality output. Ultimately improved profitability is the final outcome. ^

Gender differences in behavioral and psychosocial correlates of substance abuse among adolescents in residential treatment

This dissertation reports the results of a study that examined differences between genders in a sample of adolescents from a residential substance abuse treatment facility. The sample included 72 males and 65 females, ages 12 through 17. The data were archival, having been originally collected for a study of elopement from treatment. The current study included 23 variables. The variables were from multiple dimensions, including socioeconomic, legal, school, family, substance abuse, psychological, social support, and treatment histories. Collectively, they provided information about problem behaviors and psychosocial problems that are correlates of adolescent substance abuse. The study hypothesized that these problem behaviors and psychosocial problems exist in different patterns and combinations between genders.^ Further, it expected that these patterns and combinations would constitute profiles important for treatment. K-means cluster analysis identified differential profiles between genders in all three areas: problem behaviors, psychosocial problems, and treatment profiles. In the dimension of problem behaviors, the predominantly female group was characterized as suicidal and destructive, while the predominantly male group was identified as aggressive and low achieving. In the dimension of psychosocial problems, the predominantly female group was characterized as abused depressives, while the male group was identified as asocial, low problem severity. A third group, neither predominantly female or male, was characterized as social, high problem severity. When these dimensions were combined to form treatment profiles, the predominantly female group was characterized as abused, self-harmful, and social, and the male group was identified as aggressive, destructive, low achieving, and asocial. Finally, logistic regression and discriminant analysis were used to determine whether a history of sexual and physical abuse impacted problem behavior differentially between genders. Sexual abuse had a substantially greater influence in producing self-mutilating and suicidal behavior among females than among males. Additionally, a model including sexual abuse, physical abuse, low family support, and low support from friends showed a moderate capacity to predict unusual harmful behavior (fire-starting and cruelty to animals) among males. Implications for social work practice, social work research, and systems science are discussed. ^

Against all odds: Success stories of Latino students who survived the educational pipeline

The purpose of this interview study was to explore the experiences of Latino students, from their perspectives, as they journeyed through the educational pipeline, particularly the part focusing on the transfer experience from a 2-year college to a 4-year institution. This was accomplished by conducting in-depth interviews with 17 self-identified Latino men and women. All of the participants had attended Florida International University for at least 1 semester and had transferred from Miami Dade College. The participants varied in age, generational status, and cultural identity.^ The participants were asked to reflect on the external and internal influences that lead them to the 4-year institution. Tinto's (1993) model of student departure theory provided the theoretical framework for data collection and analysis. Based on the coding of the interviews, numerous themes emerged, including the role of the family, the impact of early education, the experiences of being Latino in Miami, the decisions to choose a college, the experience at the 2-year institution, the experience with the transfer process, and the obstacles and strategies the participants used for overcoming obstacles. These themes were furthered developed to determine which influences were most important for a successful journey through the educational pipeline. ^ The study found that viewing the pipeline via the students' perspectives juxtaposed with Tinto's (1993) model of student departure gave greater insight into the experiences of a population of students who have been underrepresented in higher education. The findings of this case study indicate that the transfer process for Latinos attending a Hispanic Serving Institution such as Florida International University, situated in a majority-minority city, is complex, with participants having to rely on peers and significant others for pertinent information and support. Several factors, including the importance of positive support networks and increased confidence nurtured by the 2-year institution, influenced the students' transfer to a 4-year institution. For professionals in the field, the findings of this study may lead to a broader understanding of the experiences of Latino students in the pipeline and, more importantly, assist college administrators and faculty in successfully guiding a population through a 4-year institution who first came via a 2-year institution. ^

A comprehensive assessment of self -report experiences of adoptive parents of special needs children in Florida

Adoption of special needs children is now seen as a life long event whereby the adoptive child and family have unique needs. The need for postplacement resources throughout the life cycle of the adoption process is evident. This exploratory-descriptive research employed a random stratified cross-sectional design. The purpose of the study was to describe, identify, examine, and assess the relative influence of identified empirically and conceptually relevant variables of self-report experiences of adoptive parents of special needs children. Primary areas of exploration included: (1) adoptive children and families' characteristics, (2) postplacement service needs, utilization and satisfaction, and (3) adoptive parents' perceptions of their adoption experiences. A proportionate stratified random mail survey was used to obtain 474 families who had adopted special needs children from the 15 geographic districts which make up the state adoption social service agency in Florida. A 144-item survey questionnaire was used to collect basic information on demographic data, service provision, and adoption experiences. Four research questions were analyzed to test the effect the predictor variables had on willingness to adopt another special needs child, successful adoption, satisfying experience, and realism about problems. All four research questions revealed that the full model and the child's antecedent and the adoptive parents' intervening variable blocks were significant in explaining the variance in the dependent variables. The child's intervening variables alone were only significant in explaining the variance for one of the dependent variables. The results of the statistical analysis on the fifth research question and the three hypotheses determined that (1) only one postplacement service, crisis intervention, had a statistically significant impact on the adoptive parents' perceived level of satisfaction with the adoption experience; (2) adoptive parents who rate their adoption as successful are more likely to express a desire to adopt another special needs child; (3) the more adequate information on the child the adoptive parents perceived that they had prior to placement, the more they perceived they were realistic about the problems they would encounter; and (4) six specific postplacement services were found to be significant in predicting successful adoptions--crisis intervention, outpatient drug/alcohol treatment, maintenance subsidy, physical therapy, special medical equipment, and family counseling. Implications for the social work field and future research are discussed. ^

Education policy and national income distribution: New evidence from recent cross -country data

In the mid 19th century, Horace Mann insisted that a broad provision of public schooling should take precedence over the liberal education of an elite group. In that regard, his generation constructed a state sponsored common schooling enterprise to educate the masses. More than 100 years later, the institution of public schooling fails to maintain an image fully representative of the ideals of equity and inclusion. Critical theory in educational thought associates the dominant practice of functional schooling with maintenance of the status quo, an unequal distribution of financial, political, and social resources. This study examined the empirical basis for the association of public schooling with the status quo using the most recent and comparable cross-country income inequality data. Multiple regression analysis evaluated the possible relationship between national income inequality change over the period 1985-2005 and variables representative of national measures of education supply in the prior decade. The estimated model of income inequality development attempted to quantify the relationship between education supply factors and subsequent income inequality developments by controlling for economic, demographic, and exogenous factors. The sample included all nations with comparable income inequality data over the measurement period, N = 56. Does public school supply affect national income distribution? The estimated model suggested that an increase in the average years of schooling among the population age 15 years or older, measured over the period 1975-1985, provided a mechanism that resulted in a more equal distribution of income over the period 1985-2005 among low and lower-middle income nations. The model also suggested that income inequality increased less or decreased more in smaller economies and when the percentage of the population age < 15 years grew more slowly over the period 1985-2000. In contrast, this study identified no significant relationship between school supply changes measured over prior periods and income inequality development over the period 1985-2005 among upper-middle and high income nations.

Fast Detection and Chemical Characterization of Gunshot Residues by CMV-GC-MS and LIBS

Gunshot residue (GSR) is the term used to describe the particles originating from different parts of the firearm and ammunition during the discharge. A fast and practical field tool to detect the presence of GSR can assist law enforcement in the accurate identification of subjects. A novel field sampling device is presented for the first time for the fast detection and quantitation of volatile organic compounds (VOCs). The capillary microextraction of volatiles (CMV) is a headspace sampling technique that provides fast results (< 2 min. sampling time) and is reported as a versatile and high-efficiency sampling tool. The CMV device can be coupled to a Gas Chromatography-Mass Spectrometry (GC-MS) instrument by installation of a thermal separation probe in the injection port of the GC. An analytical method using the CMV device was developed for the detection of 17 compounds commonly found in polluted environments. The acceptability of the CMV as a field sampling method for the detection of VOCs is demonstrated by following the criteria established by the Environmental Protection Agency (EPA) compendium method TO-17. The CMV device was used, for the first time, for the detection of VOCs on swabs from the hands of shooters, and non-shooters and spent cartridges from different types of ammunition (i.e., pistol, rifle, and shotgun). The proposed method consists in the headspace extraction of VOCs in smokeless powders present in the propellant of ammunition. The sensitivity of this method was demonstrated with method detection limits (MDLs) 4-26 ng for diphenylamine (DPA), nitroglycerine (NG), 2,4-dinitrotoluene (2,4-DNT), and ethyl centralite (EC). In addition, a fast method was developed for the detection of the inorganic components (i.e., Ba, Pb, and Sb) characteristic of GSR presence by Laser Induced Breakdown Spectroscopy (LIBS). Advantages of LIBS include fast analysis (~ 12 seconds per sample) and good sensitivity, with expected MDLs in the range of 0.1-20 ng for target elements. Statistical analysis of the results using both techniques was performed to determine any correlation between the variables analyzed. This work demonstrates that the information collected from the analysis of organic components has the potential to improve the detection of GSR.