The study of normal impedance of perforated plate acoustic liners including the effect of bias flow was studied. Two impedance models were developed, by modeling the internal flows of perforate orifices as infinite tubes with the inclusion of end corrections to handle finite length effects. These models assumed incompressible and compressible flows, respectively, between the far field and the perforate orifice. The incompressible model was used to predict impedance results for perforated plates with percent open areas ranging from 5% to 15%. The predicted resistance results showed better agreement with experiments for the higher percent open area samples. The agreement also tended to deteriorate as bias flow was increased. For perforated plates with percent open areas ranging from 1% to 5%, the compressible model was used to predict impedance results. The model predictions were closer to the experimental resistance results for the 2% to 3% open area samples. The predictions tended to deteriorate as bias flow was increased. The reactance results were well predicted by the models for the higher percent open area, but deteriorated as the percent open area was lowered (5%) and bias flow was increased. A fit was done on the incompressible model to the experimental database. The fit was performed using an optimization routine that found the optimal set of multiplication coefficients to the non-dimensional groups that minimized the least squares slope error between predictions and experiments. The result of the fit indicated that terms not associated with bias flow required a greater degree of correction than the terms associated with the bias flow. This model improved agreement with experiments by nearly 15% for the low percent open area (5%) samples when compared to the unfitted model. The fitted model and the unfitted model performed equally well for the higher percent open area (10% and 15%). / Ph. D.

The reliability of genetic evaluations across separate management units (e.g. flocks) depends on the extent of genetic links or connections among animals in these units. Where poor connectedness exists, comparisons of estimated breeding values (EBV) across units may be biased. The objectives of this study were to identify breeding strategies to increase connectedness among units, to evaluate statistics that may reflect the reduction in bias as connectedness increases in such strategies, and to assess levels of connectedness in Suffolk and Targhee flocks participating in the National Sheep Improvement Program. Expectations of bias when production units have different genetic means were derived for a simple sire model. These expectations were applied to data involving two flocks of animals with three different types of connections: sharing of a common reference sire or use of either a full- or half-sibling sire in each flock. Bias decreased as numbers of progeny in each flock increased for all methods. Linking through a reference sire was most effective and was the only method that eliminated bias as progeny numbers became infinite. Pedigree and performance data on a single trait with heritability 0.25 were then simulated for 15 flocks with 40 to 140 ewes per flock. Each flock was simulated with a different founder genetic mean to introduce bias into the genetic evaluation. Flocks participated in sire referencing schemes by artificial insemination, with varying levels of participation, or by natural service. With sire referencing genetic gain was higher and inbreeding was lower than without, and bias was rapidly reduced to near-zero levels. Discontinuing the schemes led to lower genetic gain, but bias was not reintroduced. The prediction error correlation of flock genetic means was proposed as a connectedness measure because it was strongly associated with bias. Benchmarks of 0.05 and 0.10 for "good" and "superior" connectedness were established. Targhee flocks have increased connectedness across the breed by actively exchanging rams over 15 yr. In the Suffolk breed, connectedness has only improved within segregated clusters of flocks. Suffolk breeders need to engage in active ram exchange to decrease risk of biased across-flock EBV comparisons. / Ph. D.

Microcredit programs are of great interest to economists and policymakers because of their potential for reducing poverty, particularly among women. The first chapter mainly investigates the effectiveness aspect of microcredit programs. Using program evaluation methods, we find significant improvement in women's economic condition after participating in these programs. This study also corrects for the self-selection bias that might arise due to the fact that women decide on whether to participate in the programs or not. The second chapter studies the determinants of women's economic performance in microcredit programs. These determinants are in the form of different types of characteristics of women: their own characteristics, such as age or schooling or the characteristics of the household or village they live in. One obstacle to measure the effect of observed characteristics is the problem of omitted variable bias, typically caused by unavailability of data on unobserved ability of individuals. In the absence of suitable instruments, this study finds information about unobserved ability from the marriage market. It is found that incorporating estimates of women's unobserved characteristics significantly changes the estimated effect of women's observed characteristics and substantially removes the omitted variable bias. Microcredit programs originated from Bangladesh and now three major microcredit programs are operating: Grameen Bank, BRAC and RD-12. The third chapter investigates how these different microcredit programs have been performing relative to each other. Using similar program evaluation technique as in chapter 1, we measure program impact on women's economic welfare for these programs separately. We find that BRAC outperforms Grameen Bank and RD-12 significantly. This result is interesting since it contradicts the popular notion that Grameen Bank is the most successful microcredit program. This study also tries to find the determinants of economic success of women participating in these programs, separately for each program. These results provide more insights into different aspects of microcredit program. / Ph. D.

The purpose of the study was to compare the effects on item bias of conventional testing procedures to the effects of two-stage testing procedures. It is conjectured that much of the measurement error identified as bias can be explained by factors, such as guessing or carelessness, attributable to inappropriate matching of test difficulty level and examinee ability level. Methods for detecting bias based on the-traditional definition of item difficulty fail to separate test characteristics from the ability distribution of the respondent sample. The separation of item and ability parameters, however, is an essential ingredient for an objective definition of bias. Such objectivity in measurement is provided by the Rasch latent trait model, which consequently was selected as the basis for this study. Three definitions of bias were considered, two of which were based on the Rasch model. The analyses were conducted using the scores of random subsamples (n=400 each) of black and white students on items selected from three reading subtests. The two-stage testing procedure was simulated using the real data set by "routing" students to one of three difficulty levels of the subtests based on their Rasch ability estimates as determined by a ten item routing test. Results for the two-stage testing procedure were compared with those from the conventional testing procedure at the subtest level. A reduction in the number of items identified as biased under conditions of appropriate matching of examinee ability levels and test difficulty levels was indicated by these analyses. Although the results are not conclusive, it is felt that individualizing according to the examinee's ability level offers promise in the direction of reading differential cultural measurement error. / Ph. D.

The problem addressed by this study was that of determining whether significant differences existed among selected apprehensions of black and white teachers in twelve Illinois School Districts with operative staff desegregation programs. The major assumption of this study was that both black and white teachers have apprehensions related to teaching in schools which have student and staff populations predominately of the opposite race. Three hypotheses were formulated in order to investigate the problem. Data were collected via a questionnaire which was administered to 2,250 teachers. The selected apprehensions were tabulated, and the scores were tested utilizing the chi-square test for independence. The probabilities for the events were reported at the 0.01 level. The findings indicated that both black and white teachers were apprehensive about teaching in schools with populations predominately of the opposite race. The data further revealed that there were no statistically significant differences in the choice of descriptive words used by black and white respondents to identify individuals of the opposite racial groups that they would be most willing to associate with. Further analysis of the data suggests that blacks as a group were more apprehensive about their relationships in the school setting with members of the opposite racial group. / Ed. D.

The negativity bias is a phenomenon that is characterized by infants being more influenced by, attending more to, and responding to more negative emotion information from the environment than positive emotion information. This study used a Tobii© T60 eye-tracking system to examine differences in 8- to 12-month-old infants' latencies to disengage from a centrally-presented face for three different emotion conditions-happy, sad, and fear. The events also varied by motion type-static versus dynamic. Additionally, infants' locomotor experience and parental affect served as two additional measures of experience, and assessed for their contributions to the infants' negativity bias. It was expected that infants would show longer latencies to disengage from the negative emotion events (fear or sad) compared to the positive emotion event (happy), but also that the latencies would be augmented by event type (dynamic > static), locomotion experience (high > low), and parental affect (higher negativity > lower negativity). Although infants showed more attention to dynamic than static emotion displays (especially on the speaker's mouth), and more attention to happy and sad compared to fear displays, no consistent effect of emotion type was found on infants' attention disengagement. Thus, no evidence for a negativity bias was seen. The results are interpreted with respect to possible contributions of the bimodal nature of emotion expression in the current study as well as age-related attentional differences in responding to a wide range of emotion cues. / Master of Science

The three projects described herein focus on two instances of exceptional preservation and on potential source of bias in the fossil record. The occurrence of exceptionally preserved fossil assemblages and the existence of systematic bias in the fossil record from a variety of sources represent opposing forces acting on the information quality of the fossil record. Exceptionally preserved assemblages capture features of anatomy and components of assemblages not normally recorded in the fossil record. Systematic biases affecting the fossil record do the opposite, skewing our perception of patterns of diversity, the relative dominance of clades and changes in ecosystems through time. Chapter one presents the results of an analog modeling analysis to assess whether and how a newly proposed potential mechanism, the preferential sampling of larger specimens during fossil sampling due to the greater likelihood of larger specimens being intersected by a fracture surface, contributes to the lithification bias. Chapters two and three focus on the exceptionally preserved vermiform fossils from the Winneshiek Lagerstätte in northeastern Iowa and microfossils from the Doushantuo Formation of South China, respectively. Chapter two aims at resolving the identity of the Winneshiek vermiform fossils and presents evidence that these structures represent phosphatized bromalites, an ichnologic category that includes coprolites and cololites. Chapter three presents a biostratigraphy study of exceptionally preserved microfossils at three sections of the Doushantuo Formation in South China. Acanthomorphic acritarchs represent a promising tool for subdivision and correlation of the Doushantuo Formation of South China and Ediacaran strata around the world. However, the occurrence of acanthomorphic acritarchs within the Doushantuo Formation is controlled by the availability of early diagenetic chert nodules that host microfossils such as acanthomorphic acritarchs. One of these sections contains the rare occurrence of early diagenetic cherts in an upper slope section. This new biostratigraphic data adds to the growing body of integrated chemostratigraphic and biostratigraphic data from the Doushantuo Formation. By understanding both exceptional preservation and sources of bias in the fossil record it is possible to separate artifact and noise from the true signal of the history of life. / PHD

The current study examined relations among perceptual bias, measured by comparing self performance ratings to those of an independent rater, and gender and comorbid Oppositional Defiant Disorder and Anxiety Disorder (ODD/AD) status in school-aged children with primary diagnoses of ODD. Specifically, perceptual bias of boys (N=61) and girls (N=39) with ODD with (N=43) and without comorbid AD (N=57) were examined after completing a problem solving activity with their parent(s). Measures of global functioning, executive functioning, and severity of the disorders were also examined. Based on previous findings, it was predicted that boys with ODD without AD would exhibit the greatest positive perceptual bias, followed by girls with ODD without AD, boys with ODD and AD, and, finally, girls with ODD and AD. No significant group differences emerged on the related dimensions of global functioning, executive functioning, or severity of behavioral problems. However, systematic differences in age, ADHD diagnosis, and intellectual ability were revealed among the groups, consequently they were controlled for in the final analyses. Overall, children in all groups displayed positive perceptual bias when compared to observer ratings. However, the main hypotheses were not supported. That is, children with ODD evaluated their performance higher than that of observers, independent of comorbid anxiety and gender, when controlling for the effects of age, ADHD, and intellectual ability. Implications and future directions in examining perceptual bias are discussed. / Master of Science

The prime objective of this dissertation is to design, synthesize and characterize lead-free piezoelectric based magnetostrictive components based magnetoelectric (ME) composites that exhibit self-bias characteristics and high amplitude of ME coupling. The secondary goal of this thesis was to lay down the foundation for nanoscale and flexible magnetoelectric devices. Self-biased ME effect was investigated in lead-free three-phase laminate composites. This effect is characterized by non-zero remanent ME responses at zero magnetic bias field (Hbias). It was revealed that the self-biased ME effects can be observed in three-phase laminate composites consisting of piezoelectric material and two dissimilar magnetostrictive materials. On applying Hbias to the laminates in bending mode configuration, the ME responses were found to exhibit hysteretic behaviors with remanent ME responses. The shape of hysteretic ME response could be controlled by adjusting the magnetic interactions and piezoelectric properties. Further, converse magnetoelectric (CME) responses in bending-mode three-phase laminates exhibited hysteretic behaviors with similar magnitudes during Hbias sweep as it was generated directly by applying ac voltage (Vac) without any external Hbias. Lead-free (1 - x) [0.948 K0.5Na0.5NbO3 - 0.052 LiSbO3] - x Ni0.8Zn0.2Fe2O4 (KNNLS-NZF) compositions were synthesized for optimizing ME properties of particulate composites. Island-matrix microstructure was developed to improve the magnitude of ME coupling effect by overcoming the problems found in conventional particulate composites. The structure lead to improvement of ME coefficient with maximum magnitude of 20.14 mV/cm ae as well as decrease of optimum Hbias of < 500 Oe in the composition of 0.7 KNNLS - 0.3 NZF particulate composites. Room-temperature ME phase diagram of (1 - x) BaTiO3 - x BiFeO3 materials (BT - x BFO, x = 0.025 - 1.0) was investigated for designing compositions suitable for thin film devices. The BT - x BFO compositions in narrow range of x = 0.71 - 0.8 were found to exhibit good piezoelectric, dielectric and magnetic properties simultaneously. The room temperature ME coefficient was found to be maximum with high magnitude of 0.87 mV/cmOe in the optimized composition of x = 0.725.This composition was found to consist of local monoclinic distortions with average rhombohedral symmetry as confirmed by detailed structural analysis through Raman spectroscopy and atomic pair distribution functions (PDFs). MnFe2O4 (MFO)-Ni core-shell nanoparticles were synthesized and characterized for developing tunable devices such as memristor. The MFO nanoparticles synthesized by solvothermal method exhibited diameter of 200 nm, mean primary particle size of 15 nm, high saturation magnetization of 74 emu/g and coercivity of 89 Oe. Ni encapsulation on MFO nanoparticles was performed by aqueous ionic coating method. Ni shells with uniform thickness of 1 nm were coated on MFO nanoparticles by this method. In order to develop future nanoscale dual phase energy harvesters and magnetic field sensors, vertically-aligned piezoelectric nanorods were synthesized. In the initial attempt, Pb(Zr0.52Ti0.48)O3 (PZT) was used to verify the feasibility of developing one dimensional (1D) piezoelectric nanostructures with controlled diameter and height. For the 1D nanostructure, well-ordered anodic aluminum oxide (AAO) templates were prepared by two step aluminum anodizing. The PZT nanorods were synthesized by vacuum infiltration of PZT precursor solutions and exhibited uniform diameter of 90 nm and aspect ratio of 10 with vertical in respect to the Pt-Si substrate. The piezo-response of PZT nanorods showed good magnitude owing to the reduced clamping effect from the substrate. Attempt towards the development of flexible tunable devices that possess magnetic field sensing and actuation ability was made in the later part of the thesis. The electroactive polymeric actuators in the form of Polypyrrole (PPy) / Au / Polyvinylidene fluoride (PVDF) / Au / Polypyrrole (PPy) were synthesized and the process flow was optimized. Pore size and thickness of PVDF layer was adjusted by changing the solvent, viscosity and drying temperature. Different types of electrolyte solutions were investigated to improve the strain and response time. The actuators exhibited high deflection of 90 % with fast response of 50% deflection per second. Dual-functional structure in the form of  PPy-MFO / Au / PVDF / Au / PPy-MFO was developed by PPy polymerization including MFO nanoparticles via cyclovoltammetric method. / Ph. D.

This thesis examines the extent to which institutional transparency is counterproductive and potentially politicizing within the U.S. Federal Reserve system. It exemplifies a Venn diagram intersection of political and economic theory – and given the meaningful change in behavior at the Fed – to some extent organizational theory as well. This political economy orientation may be illustrated by providing a historical context – and then addressing the relevant catalysts for change: legislative action, financial crises, and the increase in social media technology. In terms of a “broader view,” these changes have occurred against a backdrop of significant changes in the application of Keynesian theories. As a result, this thesis defines modern transparency at the Federal Reserve, including its benefits and potential drawbacks, by connecting the changes in policies and procedures over the last quarter century - and by showing the impact of the evolution of modern New Keynesian interventionist programs within this new environment. The conclusions shown the New Keynesian coincidental contributions to modern interventionalist policies. But the benefits that come from improved transparency have opened the door to unintended consequences – and the main takeaway is the potential for political bias among bankers and the time inconsistencies that come from short-term modifications to otherwise long-term problems. The “secrets of the temple” are no longer secrets…but Greider would agree that the concentration of power and political influence remains the same. / M.A. / This thesis explores to what extent is increased transparency counterproductive and potentially politicizing within the U.S. Federal Reserve system. The Fed is primarily responsible for maintaining price stability, facilitating full employment, and maintaining the health of the banking system, placing it both directly and indirectly at the center of power and influence within American politics. FOMC decisions directly affect American citizens. For instance, their interest rate policies influence the cost of a mortgage, a car loan, a student loan, or possibly the value of 401k accounts – and in the 21st century, the average American is more tied to “credit” than ever before. This analysis will consider how this initiative developed, its original intent, its evolution, and why it may result in significant unintended political consequences. The conclusions illustrated that there are benefits that come from improved transparency. However, improved transparency may have opened the door to unintended consequences.