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 Collection: UNT Theses and Dissertations
Miniature Mass Spectrometry: Theory, Development and Applications
As mass analyzer technology has continued to improve over the last fifty years, the prospect of field-portable mass spectrometers has garnered interest from many research groups and organizations. Designing a field portable instrument entails more than the scaling down of current commercial systems. Additional considerations such as power consumption, vacuum requirements and ruggedization also play key roles. In this research, two avenues were pursued in the initial development of a portable system. First, micrometer-scale mass analyzers and other electrostatic components were fabricated using silicon on insulator-deep reactive ion etching, and tested. Second, the dimensions of an ion trap were scaled to the millimeter level and fabricated from common metals and commercially available vacuum plastics. This instrument was tested for use in ion isolation and collision induced dissociation for secondary mass spectrometry and confirmatory analyses of unknowns. In addition to portable instrumentation, miniature mass spectrometers show potential for usage in process and reaction monitoring. To this end, a commercial residual gas analyzer was used to monitor plasma deposition and cleaning inside of a chamber designed for laser ablation and soft landing-ion mobility to generate metal-main group clusters. This chamber was also equipped for multiple types of spectral analysis in order to identify and characterize the clusters. Finally, a portion of this research was dedicated to method development in sample collection and analysis for forensic study. A new method for the analysis of illicit chemistries collected via electrostatic lifting is presented. This method incorporates surface-enhanced Raman microscopy as a prescreening tool for nanoextraction and nanospray ionization mass spectrometry. digital.library.unt.edu/ark:/67531/metadc407824/
Minimalism, Exoticism, and Alternatim in Tarik O’Regan’s Magnificat and Nunc Dimittis and The Ecstasies Above
Abstract British composer Tarik Hamilton O’Regan is a significant choral composer of the early twenty-first century. O’Regan’s Magnificat and Nunc Dimittis and The Ecstasies Above exhibit two notable compositional techniques: minimalism influenced by Steve Reich and exoticism representing Balinese gamelan and Andalusian music. Additionally, Reich joins the technique of minimalism with the Renaissance practice of alternatim. The examination of these works will demonstrate the application of these two compositional techniques and how he integrates them into a textural context to evoke specific historical and cultural practices. Furthermore, this study will provide guidelines for researching and performing O’Regan’s choral works by explaining O’Regan’s stylistic characteristics. digital.library.unt.edu/ark:/67531/metadc103301/
Minimality of the Special Linear Groups
Let F denote the field of real numbers, complex numbers, or a finite algebraic extension of the p-adic field. We prove that the special linear group SLn(F) with the usual topology induced by F is a minimal topological group. This is accomplished by first proving the minimality of the upper triangular group in SLn(F). The proof for the upper triangular group uses an induction argument on a chain of upper triangular subgroups and relies on general results for locally compact topological groups, quotient groups, and subgroups. Minimality of SLn(F) is concluded by appealing to the associated Lie group decomposition as the product of a compact group and an upper triangular group. We also prove the universal minimality of homeomorphism groups of one dimensional manifolds, and we give a new simple proof of the universal minimality of S∞. digital.library.unt.edu/ark:/67531/metadc279280/
A Minimally Supervised Word Sense Disambiguation Algorithm Using Syntactic Dependencies and Semantic Generalizations
Natural language is inherently ambiguous. For example, the word "bank" can mean a financial institution or a river shore. Finding the correct meaning of a word in a particular context is a task known as word sense disambiguation (WSD), which is essential for many natural language processing applications such as machine translation, information retrieval, and others. While most current WSD methods try to disambiguate a small number of words for which enough annotated examples are available, the method proposed in this thesis attempts to address all words in unrestricted text. The method is based on constraints imposed by syntactic dependencies and concept generalizations drawn from an external dictionary. The method was tested on standard benchmarks as used during the SENSEVAL-2 and SENSEVAL-3 WSD international evaluation exercises, and was found to be competitive. digital.library.unt.edu/ark:/67531/metadc4969/
Minimum levels of physical activity and perceived quality of life.
The purpose of this study was to examine the association between engaging in minimum levels of physical activity as defined by ACSM and perceived quality of life. A total of 43 college students were included in a repeated measures, quasi-experimental design research study that produced an overall retention rate of 65%, which resulted in 15 students being placed in the treatment group, and 28 students being placed in the control group. Analysis of variance with repeated measures was used to compare the quality of life mean scores over three administrations of the Quality of Life Inventory (QOLI), which resulted in no significant main effects for either the time measure or the group measure, but did produce a significant interaction effect. Post hoc analyses showed there was a significant difference between the treatment and control groups' quality of life mean scores only during the second administration of the instrument. Further analysis showed that the control group had significantly higher quality of life domain scores for six of the 16 quality of life domains. There were no significant differences between groups across any of the physiological measures. These findings did not support previous research that increasing individuals' level of physical activity will enhance their perceived quality of life. Instead, this study only provokes more questions about the connection between physical activity and perceived quality of life. digital.library.unt.edu/ark:/67531/metadc6127/
Ministerial Roles: A Study of the Professional Roles of the Minister as they are Conceived by his Reference Group, the Church Members
This study is an attempt to discover the church members' hierarchy of ministerial roles and the social significance of their evaluations. digital.library.unt.edu/ark:/67531/metadc108224/
Minor Political Parties Since 1872 and Their Influence
This study discusses the poltical parties in the United States. The writer concluded that the question whether the US will ever have a multiple party system as is maintained in European countries, can be answered only by time. digital.library.unt.edu/ark:/67531/metadc29896/
Minorities, gender, managerial jobs, and income, 1960-1990
Changes in income and representation in managerial occupations is explored separately for women and men among the United States' eight largest race/ethnic minority groups for each decennial census of 1960, 1970, 1980 and 1990 to determine how much change has occurred between 1960 and 1990 in race and ethnic inequality, and in gender inequality within each race/ethnic group. Insights from gender theory are applied to minority group inequality and insights from minority group theory are applied to gender inequality with some degree of success. Economic change is uneven among the groups, with the largest specific change being the movement of women into managerial jobs. A clear pattern also emerged indicating that the higher the average representation of a minority group in managerial jobs, the greater the gap between women and men. The income of all persons with income, however, did not exhibit such a clear pattern across the different groups. digital.library.unt.edu/ark:/67531/metadc2882/
Minority Hiv Rates, Inequality, and the Politics of Aids Funding
Since the 1990s, the HIV/AIDS epidemic has increasingly impacted minority groups in the United States, particularly African Americans. Why is this happening? Comparative studies of developing nations have convincingly established a relationship between concentrated poverty, ethnic boundaries, and lack of effective governmental response as contributing to high levels of infection in those countries. To date, however, no study has sought to apply these insights to the American context. This dissertation endeavors to show that, first, marginalization of U.S. sub-groups most at risk of infection is largely a product of poor health outcomes associated with concentrated urban poverty and economic stratification. Second, this sub-group marginalization is exacerbated by the politics of retrenchment which increasingly privatizes risks onto individuals, states, and non-governmental providers. The net result of these changes is a U.S. health care system too fractured to recognize and respond to changes in HIV/AIDS demographics. digital.library.unt.edu/ark:/67531/metadc177231/
Miranda Reasoning and Competent Waiver Decisions: Are Models of Legal Decision Making Applicable?
Miranda understanding, appreciation, and reasoning abilities are essential to courts' determinations of knowing and intelligent Miranda rights waivers. Despite the remarkable development of Miranda research in recent decades, studies have generally focused on understanding and appreciation of Miranda rights, but have not examined Miranda reasoning and waiver decisions. Therefore, examining the nature of defendants' decisional capacities constitutes a critical step in further developing theoretical and clinical models for competent Miranda waiver decisions. The current study evaluated Miranda waiver decisions for 80 pretrial defendants from two Tulsa-area Oklahoma jails. Previously untested, the current study examined systematically how rational decision abilities affect defendants' personal waiver decisions. Components from general models of legal decision making, such as decisional competence and judgment models, were examined to determine their applicability to Miranda waiver decisions. digital.library.unt.edu/ark:/67531/metadc271782/
Mis Raices, Mi Hogar: My Roots, My Home
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The lack of ancestral record instilled in me this desire to hold on to memories, and to leave my children with permanent records or memories of our family. My desire to work with metals was inspired by the need to encapsulate a record of memories through a more permanent means. The durability of steel, I feel, can be used as a diary, in the form of an artistic and lasting object, rather than written words. The need to leave behind a legacy inspired me to explore the use of lockets and containers that have some resemblance to a reliquary. My intent was not one of religious purpose, but rather to create a locket or container that would reflect or contain symbols of where one's roots begin, the home. digital.library.unt.edu/ark:/67531/metadc5790/
Miscegenated Narration: The Effects of Interracialism in Women's Popular Sentimental Romances from the Civil War Years
Critical work on popular American women's fiction still has not reckoned adequately with the themes of interracialism present in these novels and with interracialism's bearing on the sentimental. This thesis considers an often overlooked body of women's popular sentimental fiction, published from 1860-1865, which is interested in themes of interracial romance or reproduction, in order to provide a fuller picture of the impact that the intersection of interracialism and sentimentalism has had on American identity. By examining the literary strategy of "miscegenated narration," or the heteroglossic cacophony of narrative voices and ideological viewpoints that interracialism produces in a narrative, I argue that the hegemonic ideologies of the sentimental romance are both "deterritorialized" and "reterritorialized," a conflicted impulse that characterizes both nineteenth-century sentimental, interracial romances and the broader project of critiquing the dominant national narrative that these novels undertake. digital.library.unt.edu/ark:/67531/metadc67958/
Misinformation About the Misinformation Effect
This study partially replicated the research of Cook, Kwak, Hoffman, & Loftus where they examined post-event activities that induces subjects to pick a wrong person in a forced choice identification procedure. The goal was to investigate if providing a neither option to a match to sample task increases the accuracy of responding. Subjects were asked to study three faces for 10 seconds, after which they were asked to pick out the faces in a forced choice setting where two other faces were presented. Later the subjects were asked to pick out faces in a setting in which they could use a neither option. Results indicated that a generalization effect occurs when identifying faces and the effect is seen as subjects choosing the wrong face. This suggests that when using faces with some similar features in a lineup setting the procedure may cause the subject to pick the wrong person. digital.library.unt.edu/ark:/67531/metadc149598/
Missa Papae Marcelli: A Comparative Analysis of the Kyrie and Gloria Movements of Giovanni Pierluigi da Palestrina and an Adaptation by Giovanni Francesco Anerio
Missa Papae Marcelli: A Comparative Analysis of the Kyrie and Gloria Movements of Giovanni Pierluigi da Palestrina and an Adaptation by Giovanni Francesco Anerio digital.library.unt.edu/ark:/67531/metadc5257/
Missed Opportunities: Examining The LiteracyExperiences Of African American Students Displaced By Hurricane Katrina.
The purpose of this study was to examine how five African American middle school students, who were displaced by Hurricane Katrina represent their literacy experiences before, during, and after their displacement. Specifically, the two research questions were: (a) What are the stories that these middle school students tell about their lives, before, during, and after their displacement, and (b) What do their stories reveal about their literacy experience before, during, and after their displacement? Narrative Inquiry was the chosen methodology for the study, which allowed the participants to tell their experiences from a first-person perspective. It also encouraged the participants to reflect upon these experiences, in order to give meaning to their thoughts and emotions. Employing a critical lens and perspective, I constructed a narrative profile for each participant, which was then analyzed using these methods. Each narrative profile detailed the literacy experiences of the participants before Hurricane Katrina, during the transition period, and current literacy experiences now that the participants are resettled and attending school in the host city. These data were supplemented by archival data such as report cards, individual education plans (IEPs), and Texas Assessment of Knowledge and Skills (TAKS) scores. Data analysis of the five participants’ literacy experiences revealed common themes. These participants have pleasant memories of school literacy before the storm and mentioned “choice” as a component of those experiences. During the transition period, few or no literacy experiences took place. Hence, there were missed opportunities for the participants to use literacy experiences to make connections to their new world. Participants reported current classroom and school experiences were controlled environments that led to controlled literacy experiences. This compartmentalization of literacy experiences is not consistent with the critical literacy perspective adopted in this study. Their interviews suggested that they that they saw no connection between school literacy and their literacy experiences outside school. digital.library.unt.edu/ark:/67531/metadc103373/
Missing Data Treatments at the Second Level of Hierarchical Linear Models
The current study evaluated the performance of traditional versus modern MDTs in the estimation of fixed-effects and variance components for data missing at the second level of an hierarchical linear model (HLM) model across 24 different study conditions. Variables manipulated in the analysis included, (a) number of Level-2 variables with missing data, (b) percentage of missing data, and (c) Level-2 sample size. Listwise deletion outperformed all other methods across all study conditions in the estimation of both fixed-effects and variance components. The model-based procedures evaluated, EM and MI, outperformed the other traditional MDTs, mean and group mean substitution, in the estimation of the variance components, outperforming mean substitution in the estimation of the fixed-effects as well. Group mean substitution performed well in the estimation of the fixed-effects, but poorly in the estimation of the variance components. Data in the current study were modeled as missing completely at random (MCAR). Further research is suggested to compare the performance of model-based versus traditional MDTs, specifically listwise deletion, when data are missing at random (MAR), a condition that is more likely to occur in practical research settings. digital.library.unt.edu/ark:/67531/metadc84282/
Missionary Millennium: The American West; North and West Africa in the Christian Imagination
During the 1890s in the United States, Midwestern YMCA missionaries challenged the nexus of power between Northeastern Protestant denominations, industrialists, politicians, and the Association's International Committee. Under Kansas YMCA secretary George Fisher, this movement shook the Northeastern alliance's underpinnings, eventually establishing the Gospel Missionary Union. The YMCA and the GMU mutually defined foreign and domestic missionary work discursively. Whereas Fisher's pre-millennial movement promoted world conversion generally, the YMCA primarily reached out to college students in the United States and abroad. Moreover, the GMU challenged social and gender roles among Moroccan Berbers. Fisher's movements have not been historically analyzed since 1975. Missionary Millennium is a reanalysis and critical reading of religious fictions about GMU missionaries, following the organization to its current incarnation as Avant Ministries. digital.library.unt.edu/ark:/67531/metadc11043/
The Missionary Work of Samuel A. Worcester Among the Cheroke, 1825-1840
Worcester made two major contributions to the Cherokee before his death at Park Hill in 1859. First was his faith and the propagation of Christianity among them. However, this was done by other missionaries both before and after him. But his truly unique accomplishment was his work with the Cherokee language. digital.library.unt.edu/ark:/67531/metadc131307/
Mist and Microstructure Characterization in End Milling Aisi 1018 Steel Using Microlubrication
Flood cooling is primarily used to cool and lubricate the cutting tool and workpiece interface during a machining process. But the adverse health effects caused by the use of flood coolants are drawing manufacturers' attention to develop methods for controlling occupational exposure to cutting fluids. Microlubrication serves as an alternative to flood cooling by reducing the volume of cutting fluid used in the machining process. Microlubrication minimizes the exposure of metal working fluids to the machining operators leading to an economical, safer and healthy workplace environment. In this dissertation, a vegetable based lubricant is used to conduct mist, microstructure and wear analyses during end milling AISI 1018 steel using microlubrication. A two-flute solid carbide cutting tool was used with varying cutting speed and feed rate levels with a constant depth of cut. A full factorial experiment with Multivariate Analysis of Variance (MANOVA) was conducted and regression models were generated along with parameter optimization for the flank wear, aerosol mass concentration and the aerosol particle size. MANOVA indicated that the speed and feed variables main effects are significant, but the interaction of (speed*feed) was not significant at 95% confidence level. The model was able to predict 69.44%, 68.06% and 42.90% of the variation in the data for both the flank wear side 1 and 2 and aerosol mass concentration, respectively. An adequate signal-to-noise precision ratio more than 4 was obtained for the models, indicating adequate signal to use the model as a predictor for both the flank wear sides and aerosol mass concentration. The highest average mass concentration of 8.32 mg/m3 was realized using cutting speed of 80 Surface feet per minute (SFM) and a feed rate of 0.003 Inches per tooth (IPT). The lowest average mass concentration of 5.91 mg/m3 was realized using treatment 120 SFM and 0.005 IPT. The cutting performance under microlubrication is five times better in terms of tool life and two times better in terms of materials removal volume under low cutting speed and feed rate combination as compared to high cutting speed and feed rate combination. Abrasion was the dominant wear mechanism for all the cutting tools under consideration. Other than abrasion, sliding adhesive wear of the workpiece materials was also observed. The scanning electron microscope investigation of the used cutting tools revealed micro-fatigue cracks, welded micro-chips and unusual built-up edges on the cutting tools flank and rake side. Higher tool life was observed in the lowest cutting speed and feed rate combination. Transmission electron microscopy analysis at failure for the treatment 120 SFM and 0.005 IPT helped to quantify the dislocation densities. Electron backscatter diffraction (EBSD) identified 4 to 8 µm grain size growth on the machined surface due to residual stresses that are the driving force for the grain boundaries motion to reduce its overall energy resulting in the slight grain growth. EBSD also showed that (001) textured ferrite grains before machining exhibited randomly orientated grains after machining. The study shows that with a proper selection of the cutting parameters, it is possible to obtain higher tool life in end milling under microlubrication. But more scientific studies are needed to lower the mass concentration of the aerosol particles, below the recommended value of 5 mg/m3 established by Occupational Safety and Health Administration (OSHA). digital.library.unt.edu/ark:/67531/metadc283858/
Mist Characterization in Drilling 1018 Steel
Minimum quantity lubrication replaces the traditional method of flood cooling with small amounts of high-efficient lubrication. Limited studies have been performed to determine the characteristics of mist produced during MQL. This study investigated the mist concentration levels produced while drilling 1018 steel using a vegetable based lubricant. ANOVA was performed to determine whether speed and feed rates or their interactions have a significant effect on mist concentration levels and particle diameter. It was observed that the concentration levels obtained under all four speed and feed rate combinations studied exceeded the current OSHA and NIOSH standards. digital.library.unt.edu/ark:/67531/metadc149573/
Mitochondrial DNA Sequence Variation in Populations of the Nine-Banded Armadillo, Dasypus novemcinctus
Four populations of nine-banded armadillos, Dasypus novemcinctus, were investigated in the south-central United States in order to assess genetic variation in an isolated population (Electric Island, Lake Hamilton, Garland County, Arkansas); a semi-isolated population (Arkansas Post, Arkansas County, Arkansas), and two free ranging populations (southern Arkansas and central Texas). A 233 basepair sequence of the D-loop region of mitochondrial DNA was sequenced in individuals from each population. Individuals and populations were compared to assess relatedness among populations and individuals. Higher sequence diversity was detected in the semi-isolated population, while lower sequence diversity was observed in the isolated and free ranging populations. Overall, all populations exhibited low genetic variation when compared to genetic variation for other mammals. The results support the hypothesis that rapid range expansion combined with the organism's unique reproductive strategies have promulgated low genetic variation in the North American populations of nine-banded armadillos. digital.library.unt.edu/ark:/67531/metadc2577/
Mixed Alkyllithim/Lithium Alkoxide Aggregates with Less Sterically Crowded Alkyl Groups
Mixed alkyllithium / lithium alkoxide aggregates in the form (RLi)n(ROLi)m were formed by addition of corresponding alcohol compounds at different Li/O ratios. Variable temperature 13C and 6Li NMR spectroscopy were used to verify the formation of the mixed aggregates and to study their behavior in hydrocarbon solution. Spectra for the lithium n-propoxide / n-propyllithium and iso-butyllithium / lithium iso-butoxide systems each indicated at least one mixed aggregate. digital.library.unt.edu/ark:/67531/metadc278441/
Mixed Culture of Chlorella Pyrenoidosa TX71105 and a Variant Strain of Bacillus Megaterium
Very little work has been done on bacteria capable of significantly inhibiting algal growth. This thesis reports the research on mixed cultures of a high-temperature strain of algae, Chlorella pyrenoidosa TX71105, and an organism isolated from the air and tentatively identified as a variant strain of Bacillus megaterium. digital.library.unt.edu/ark:/67531/metadc131311/
A Mixed Method Analysis of Undergraduate Student-run Public Relations Firms on U.S. College Campuses
Student-run public relations firms are part of collegiate public relations pedagogy, and this study used a mixed-method approach to analyze such firms on U.S. campuses. A listing of campuses with student-run firms was created as part of this study. Through an online survey questionnaire, advisers from 55 of the 119 student-run firms provided data about firm characteristics and observations about student learning and career development. Multiple correspondence analyses was used to see if the firms grouped into clusters and somewhat aligned with previous research by Lee Bush in 2009. Firms clustered into four groups, with the fourth group representing a mix of the other three. One additional finding was that firm characteristics are more similar than dissimilar even when comparing firms of varying years in operation. Analysis of variance to compare characteristics between different types of firms revealed that one type of firm tended to employ students at a higher average number of hours per week (F = 6.61, eta squared=0.16) and one was more likely to be accredited by the Accrediting Council on Education in Journalism and Mass Communications (F = 3.71, eta squared=0.13). Advisers reported mostly positive reflections on observed transformations they see in their student workers and the value of the firm experience including how it helps students in post-graduation job attainment. Responses to a graduate questionnaire is included but, because of low response rate (N = 6), provided only cursory information. digital.library.unt.edu/ark:/67531/metadc30486/
A Mixed-Methods Approach to the Experiences of Non-Offending Parents of Children who have Experienced Sexual Abuse Participating in Child Parent Relationship Therapy (CPRT)
When a child has been sexually abused, the non-offending parent and child may benefit from an intervention aimed at enhancing the parent child relationship. This mixed-methods study examined the process of child parent relationship therapy (CPRT) with non-offending parents of children who had been sexually abused. One purpose of the present study was to examine change in parent-child relationship, child behavior, and parent empathy of non-offending parents whose children have been sexually abused after participation in CPRT. A secondary purpose of this study was to explore subjective experiences of non-offending parents who participate in CPRT. Participants (N = 8) completed 11 weeks of CPRT in either Spanish speaking (n = 4) or English speaking (n = 4) groups. All participants completed pretest and posttest instruments including Child Behavior Checklist, Parenting Stress Index, and Measurement of Empathy in Adult-Child Interaction. Pretest and posttest means were reported but because of small sample size, only descriptive statistics are reported. Possible trends in pretest/posttest mean scores of the quantitative instruments are discussed. All participants also completed a post semi-structured interview to account for the experience of participants qualitatively. Analysis of the qualitative data revealed enhanced parent-child relationships, improved communication, greater acceptance, positive parental internal changes, positive behavioral changes in child, and positive changes in discipline. digital.library.unt.edu/ark:/67531/metadc30525/
A Mixed-methods Study Investigating the Relationship Between Media Multitasking Orientation and Grade Point Average
The intent of this study was to examine the relationship between media multitasking orientation and grade point average. The study utilized a mixed-methods approach to investigate the research questions. In the quantitative section of the study, the primary method of statistical analyses was multiple regression. The independent variables for the study were media multitasking orientation, gender, age, and income. The dependent variable for the study was grade point average. Three out of four independent variables, namely, media multitasking orientation, gender and age were statistically significant predictors of grade point average. In the qualitative section of the study, seven participants were interviewed to determine how individual differences in media multitasking orientation manifest themselves in academic settings. digital.library.unt.edu/ark:/67531/metadc177221/
MMPI-2 Correlates of Chronic Pain: An Examination of the Role of Anger
The primary purpose of the present study was to examine the potential relationships that exist between anger expression, as measured by several MMPI-2 scales, and chronic pain. digital.library.unt.edu/ark:/67531/metadc278262/
MMPI-2 Patterns of Adults with Attention-Deficit Hyperactivity Disorder
Recent literature suggests that not only does Attention-deficit Hyperactivity Disorder (ADHD/ADD) persist into adulthood, but it can also be accompanied by personality characteristics which cause emotional difficulties. In fact, adults diagnosed with ADHD can present with a profusion of difficulties. Several constructs appear to accumulate dynamically throughout development to place the adult with ADHD at risk for multiple emotional problems. These interwoven influences include familial characteristics, childhood emotional and academic difficulties, and inadequate coping skills to respond to adulthood pressures. This document, first, describes a developmental model for conceptualizing negative trajectories leading to nonadaptive coping and psychopathology and identifies personality factors of adults diagnosed with ADHD. This model provides clinicians and researchers with a better understanding of the complexity and challenges of adulthood ADHD in order to aid in diagnosis, treatment, and prevention. The purpose of this study is to examine personality factors common to adults diagnosed with ADHD and compares these characteristics with a group of adults diagnosed with a depressive disorder. Adults responding to a community advertisement who provided documentation of the diagnosis of Attention-deficit Hyperactivity Disorder were administered the MMPI-2. This ADHD group was compared with MMPI-2 profiles of a group of adults diagnosed with Major Depressive Disorder or Dysthymic Disorder. A cluster analysis procedure was performed and results are discussed. digital.library.unt.edu/ark:/67531/metadc277675/
Mobil Oil Corporation : Evolution of Its Corporate Identity
The purpose of this thesis is to explain this evolution of Mobil's corporate identity, and to determine the effect of the 1911 dissolution decree on it. digital.library.unt.edu/ark:/67531/metadc131300/
Mobile agent security through multi-agent cryptographic protocols.
An increasingly promising and widespread topic of research in distributed computing is the mobile agent paradigm: code travelling and performing computations on remote hosts in an autonomous manner. One of the biggest challenges faced by this new paradigm is security. The issue of protecting sensitive code and data carried by a mobile agent against tampering from a malicious host is particularly hard but important. Based on secure multi-party computation, a recent research direction shows the feasibility of a software-only solution to this problem, which had been deemed impossible by some researchers previously. The best result prior to this dissertation is a single-agent protocol which requires the participation of a trusted third party. Our research employs multi-agent protocols to eliminate the trusted third party, resulting in a protocol with minimum trust assumptions. This dissertation presents one of the first formal definitions of secure mobile agent computation, in which the privacy and integrity of the agent code and data as well as the data provided by the host are all protected. We present secure protocols for mobile agent computation against static, semi-honest or malicious adversaries without relying on any third party or trusting any specific participant in the system. The security of our protocols is formally proven through standard proof technique and according to our formal definition of security. Our second result is a more practical agent protocol with strong security against most real-world host attacks. The security features are carefully analyzed, and the practicality is demonstrated through implementation and experimental study on a real-world mobile agent platform. All these protocols rely heavily on well-established cryptographic primitives, such as encrypted circuits, threshold decryption, and oblivious transfer. Our study of these tools yields new contributions to the general field of cryptography. Particularly, we correct a well-known construction of the encrypted circuit and give one of the first provably secure implementations of the encrypted circuit. digital.library.unt.edu/ark:/67531/metadc4473/
Mobile Order Theory as Applied to Polycyclic Aromatic Heterocycles
Experimental mole fraction solubilities of benzil, thianthrene, trans-stilbene, thioxanthen-9-one, diphenyl sulfone and dibenzothiophene sulfone are determined in pure noncomplexing and complexing solvents. Predicted solubility values are calculated for benzil, thianthrene, trans-stilbene and thioxanthen-9-one using expressions derived from Mobile Order theory. Large deviations between experimental and predicted solubilities in alcohol solvents exist, therefore optimized solute - solvent association constants are determined. Previously measured thianthrene solubilities in five binary alkane + cyclohexane solvent mixtures are compared with values predicted from Mobile Order theory using the measured solubility in each of the pure solvents as input parameters. The experimental mole fraction solubility of benzil in eight binary alcohol + 1-octanol solvent mixtures are also measured and compared with predicted values. digital.library.unt.edu/ark:/67531/metadc278994/
Mobiles
Mobiles is a composition for an ensemble consisting of 12 instruments. The piece, in one movement, incorporates intuition, chance, and twelve tone techniques and reflects the relationship between motion and rest or tension and release. The structure is modeled according to principles of growth and decay, starting off slowly, building, and then dying away. Much of the material is inspired by mental images invoked from modern theories concerning chaos. Mobiles' character stems from the principal use of two motives, the chaos motif and the echo motif. Primarily, the chaos motif is representative of a state of motion while the echo motif represents a state of rest. Mobile architecture is usually characteristic of symmetry, balance, and proportion, but because of uncertainty in a natural environment, this proportion often falls short of a perfect symmetrical balance as in the case of a crystal or a fractal design. It is this kind of architecture that Mobiles portrays in its form and developmental process. digital.library.unt.edu/ark:/67531/metadc278749/
A Model for a Speech and Drama Program for an Upper-Division College: Tyler State College
The problem of this study is that of developing a speech and drama program for Tyler State College which is consistent with the philosophical framework of the college as well as with the scope of upper-division institutions in Texas as stated by the Coordinating Board, Texas College and University System. Emphasis is placed on the matriculation of students from junior colleges within commuting distance of Tyler. digital.library.unt.edu/ark:/67531/metadc278458/
A model for designing a new telecommunication system in Mongolia
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The objective of this research is to design, and determine the feasibility of, a telecommunication system for the city of Erdenet, Mongolia. The Mongolian Telecommunication Company, Telecommunication Company of Erdenet city, and the National Statistical Office of Mongolia provided the data required for telecommunication forecasting of Erdenet. The literature review and analysis of the telecommunication forecasting indicate the need for a model of a new Telecommunication system in Erdenet, Mongolia. The model, as indicated, should become a useful example for planning and updating the telecommunication system in Mongolia. The design of a proposed telecommunication network involves the following considerations: analyzing and forecasting telephone traffic, calculating the required number of channels, determining exchange locations, traffic matrix, and establishing a basic hierarchical structure. digital.library.unt.edu/ark:/67531/metadc2768/
A model for developing and disseminating multimedia materials for teacher educators.
The purpose of this study was to develop a model that would enhance the development, dissemination, and adoption of educational multimedia materials. The grounded theory definition of open coding was used to analyze data collected from the 3-year Technology Leadership Web Library Project at the University of North Texas. Weekly meeting minutes, email communication, reports, notes, questionnaires, and surveys were examined to determine major factors involved in the process of product development and dissemination. From the analysis of this study, five major factors in product development and dissemination were identified. These factors were leadership, team dynamics, expert advisors, feedback, and consumers. The synthesis of the factors led to the development of the PROMOTE (process revolving around ongoing management of team and evaluative feedback) model. The PROMOTE model is based on the establishment of a system that includes leadership, development team, and expert advisors at its center. The system is tied together with well-established feedback loops for stages of evaluation. The PROMOTE model is iterative and uses consumer feedback to generate new products. The PROMOTE model differs from other product development and evaluation models both in the focus of the process and the nature of the evaluation feedback. digital.library.unt.edu/ark:/67531/metadc3342/
A model for the development of disordered eating among lesbians
It has only been in recent years that eating disorder researchers have begun focusing on sexual orientation as a variable that may affect prevalence rates. Heeding the call for studies that extend beyond identification of fixed eating disorder risk factors (e.g., gender), this study was designed to explore factors that contribute to the development of disordered eating among lesbians. In this study, a hypothesized Lesbian Model of Disordered Eating was tested using structural equation modeling. Lesbian Sexual Identity and Social Supports were hypothesized to positively influence Psychological Health. In addition, Internalization of U.S. Societal Norms of beauty and attractiveness was hypothesized to negatively affect Psychological Health. Psychological Health, in turn, was hypothesized to negatively influence Body Image Concerns. Body Image Concerns was then hypothesized to positively affect Disordered Eating. The fit of the model was evaluated and one of the hypothesized pathways, Internalization of Norms was moved to directly predict Body Image Concerns. After adjusting the model, the model accounted for 54% of the variance in disordered eating. Most notably, the results highlight the potential affects of adopting a positive lesbian identity on disordered eating and underscore the importance of including sexual identity as a demographic variable in studies of body image and disordered eating. Implications for counseling and directions for future research are discussed. digital.library.unt.edu/ark:/67531/metadc3241/
A model of best practice: Leadership development programs in the nuclear industry.
This study looked at leadership development at top performing nuclear plants in the United States. The examination of leadership development as actually practiced in the nuclear energy industry lead to the development of a best practice model. The nuclear industry is self-regulated through the Institute for Nuclear Power Operations (INPO). INPO has been evaluating nuclear plants over the past 15 years. Recently they have identified supervisor performance as a key factor in poor plant performance. INPO created a model for leadership development called Growing Industry Leaders. The nuclear industry has identified its aging workforce and subsequent loss of leadership as an emerging issue facing the nuclear industry in the next five to ten years. This initiative was aimed at both the supervisor shortfalls identified through plant evaluations and the state of the workforce within the nuclear industry. This research evaluated the elements of this model and compared them to a model of best practice. This research answered the following questions: What elements of leadership development should be included in leadership development programs? What would a model of best practice in leadership development look like? Data was collected from nine out of 103 top performing plants. Development activities were categorized by a seven member panel of experts. These categories were then validated using three rounds of a Delphi process to reach consensus. This became the basis for the best practice model for leadership development. digital.library.unt.edu/ark:/67531/metadc5307/
A Model of Information Therapy: Definition and Empirical Application
This study involves the investigation of the basis and validity of considering health information as therapeutic, the definition of Information Therapy, and whether the therapeutic nature of information can be measured empirically. The purpose of the study is to determine if there are any significant differences in the therapeutic effect of Information Therapy through the different delivery modes of support groups communicating face-to-face and those utilizing computer-mediated communication on the Internet. The comparison of these groups revealed no significant differences on three measures of health: physical, mental, and social support. Because one communication medium is not found to be advantageous over the other, the use of the computer can extend the benefits of Information Therapy to the home-bound, to those in remote areas, to people with time restraints, and those who may be shy. The validity of the therapeutic nature of information was verified by participant report of the effect of a health information search. Results demonstrated that the primary source for information is the physician, followed by the Internet, and 77% of participants reported a positive or therapeutic effect when health information was found. These results are significant because individuals who are in positions to deliver Information Therapy can better meet needs by identification of the sources to which people look for information and can have a major impact on patient care and the general health of the population. Providing people with information can empower them to take an active role in their health, can increase confidence in self-care, and should provide coping and disease management skills thus decreasing the utilization of healthcare resources and preventing costly acute and chronic health complications. digital.library.unt.edu/ark:/67531/metadc277931/
Modeling Alcohol Consumption Using Blog Data
How do the content and writing style of people who drink alcohol beverages stand out from non-drinkers? How much information can we learn about a person's alcohol consumption behavior by reading text that they have authored? This thesis attempts to extend the methods deployed in authorship attribution and authorship profiling research into the domain of automatically identifying the human action of drinking alcohol beverages. I examine how a psycholinguistics dictionary (the Linguistics Inquiry and Word Count lexicon, developed by James Pennebaker), together with Kenneth Burke's concept of words as symbols of human action, and James Wertsch's concept of mediated action provide a framework for analyzing meaningful data patterns from the content of blogs written by consumers of alcohol beverages. The contributions of this thesis to the research field are twofold. First, I show that it is possible to automatically identify blog posts that have content related to the consumption of alcohol beverages. And second, I provide a framework and tools to model human behavior through text analysis of blog data. digital.library.unt.edu/ark:/67531/metadc271843/
Modeling and reduction of gate leakage during behavioral synthesis of nanoscale CMOS circuits.
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The major sources of power dissipation in a nanometer CMOS circuit are capacitive switching, short-circuit current, static leakage and gate oxide tunneling. However, with the aggressive scaling of technology the gate oxide direct tunneling current (gate leakage) is emerging as a prominent component of power dissipation. For sub-65 nm CMOS technology where the gate oxide (SiO2) thickness is very low, the direct tunneling current is the major form of tunneling. There are two contribution parts in this thesis: analytical modeling of behavioral level components for direct tunneling current and propagation delay, and the reduction of tunneling current during behavioral synthesis. Gate oxides of multiple thicknesses are useful in reducing the gate leakage dissipation. Analytical models from first principles to calculate the tunneling current and the propagation delay of behavioral level components is presented, which are backed by BSIM4/5 models and SPICE simulations. These components are characterized for 45 nm technology and an algorithm is provided for scheduling of datapath operations such that the overall tunneling current dissipation of a datapath circuit under design is minimal. It is observed that the oxide thickness that is being considered is very low it may not remain constant during the course of fabrication. Hence the algorithm takes process variation into consideration. Extensive experiments are conducted for various behavioral level benchmarks under various constraints and observed significant reductions, as high as 75.3% (with an average of 64.3%). digital.library.unt.edu/ark:/67531/metadc5590/
Modeling Changes in End-user Relevance Criteria : An Information Seeking Study
This study examines the importance of relevance criteria in end-user evaluation of valuable or high relevant information. digital.library.unt.edu/ark:/67531/metadc278355/
Modeling Complex Forest Ecology in a Parallel Computing Infrastructure
Effective stewardship of forest ecosystems make it imperative to measure, monitor, and predict the dynamic changes of forest ecology. Measuring and monitoring provides us a picture of a forest's current state and the necessary data to formulate models for prediction. However, societal and natural events alter the course of a forest's development. A simulation environment that takes into account these events will facilitate forest management. In this thesis, we describe an efficient parallel implementation of a land cover use model, Mosaic, and discuss the development efforts to incorporate spatial interaction and succession dynamics into the model. To evaluate the performance of our implementation, an extensive set of simulation experiments was carried out using a dataset representing the H.J. Andrews Forest in the Oregon Cascades. Results indicate that a significant reduction in the simulation execution time of our parallel model can be achieved as compared to uni-processor simulations. digital.library.unt.edu/ark:/67531/metadc4305/
Modeling Infectious Disease Spread Using Global Stochastic Field Simulation
Susceptibles-infectives-removals (SIR) and its derivatives are the classic mathematical models for the study of infectious diseases in epidemiology. In order to model and simulate epidemics of an infectious disease, a global stochastic field simulation paradigm (GSFS) is proposed, which incorporates geographic and demographic based interactions. The interaction measure between regions is a function of population density and geographical distance, and has been extended to include demographic and migratory constraints. The progression of diseases using GSFS is analyzed, and similar behavior to the SIR model is exhibited by GSFS, using the geographic information systems (GIS) gravity model for interactions. The limitations of the SIR and similar models of homogeneous population with uniform mixing are addressed by the GSFS model. The GSFS model is oriented to heterogeneous population, and can incorporate interactions based on geography, demography, environment and migration patterns. The progression of diseases can be modeled at higher levels of fidelity using the GSFS model, and facilitates optimal deployment of public health resources for prevention, control and surveillance of infectious diseases. digital.library.unt.edu/ark:/67531/metadc5335/
Modeling of land use change effects on storm water quantity and quality in the City of Carrollton and the North Texas Area.
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Development and population are rapidly increasing in urbanizing areas of North Texas and so is the need to understand changes in storm water runoff flow and its contamination by nutrients, sediment, pesticides and other toxicants. This study contributes to this understanding and has two primary components: first, development of a graphical user interface for a geographic information system and storm water management database, and second, performing a two-scale hydrological modeling approach (the US Corp of Engineers HEC-HMS model and the US Environmental Protection Agency SWMM model). Both primary components are used together as a toolkit to support the storm water management program of the City of Carrollton, located in North Texas. By focusing limited city resources, the toolkit helps storm water managers in the process of compliance with federal regulations, especially the National Pollution Discharge Elimination System permit, and provides guidance for reporting, planning and investigation. A planning example was conducted by modeling potential changes in storm water quality due to projections of land use based on the City of Carrollton's Comprehensive Plan. An additional component of this study is the evaluation of future changes in surface water quantity and quality in the North Central Texas area, specifically in a rural but rapidly urbanizing subbasin area of the greater Lake Lewisville watershed. This was accomplished using the US Corp of Engineers HEC-HMS hydrological model. Precipitation scenarios were derived from years of historically high, medium, and low annual precipitation. Development scenarios were derived from current land use in the Lake Lewisville sub basin, current land use in the city of Carrollton, and from Markov projections based on recent land use change calculated from satellite images of 1988 and 1999. This information is useful for future land use planning and management of water resources in North Texas. digital.library.unt.edu/ark:/67531/metadc4368/
Modeling Place Vulnerability of HIV/AIDS in Texas
This study provides a measurable model of the concept of place vulnerability for HIV/AIDS that incorporates both community and structural level effects using data provided at the ZIP code level from the Texas Department of State Health Services. Sociological literature on the effects of place on health has been growing but falls short of providing an operational definition of the effects of place on health. This dissertation looks to the literature in medical/health geography to supplement sociology’s understanding of the effects of place on health, to the end of providing a measurable model. Prior research that has recognized the complexity of the effects of place still have forced data into one scale and emphasized individual-level outcomes. A multilevel model allows for keeping the associated spatial unit data, without aggregating or parsing it out for convenience of model fit. The place vulnerability model proposed examines how exposure, capacity and potentiality variables all influence an area’s HIV/AIDS count. To capture the effects of place vulnerability at multiple levels, this dissertation research uses a multilevel zero-inflated poisson (MLZIP) model to examine how factors measured at the ZIP code and county both affect HIV/AIDS counts per ZIP code as an outcome. Furthermore, empirical Bayes estimates are mapped to display how well the model fits across the state of Texas. Limitations of this research include the need to incorporate time, more specific predictors, and individual level factors. The methodology developed permits a more thorough understanding of place effects on the spatial variation of HIV/AIDS. digital.library.unt.edu/ark:/67531/metadc84211/
Modeling Student Perception of Web 2.0 Technologies Adoption in Kuwait
The primary focus of this dissertation was to explore students' perceptions of adopting Web 2.0 applications at the School of Basic Education (SBE) in Kuwait. Although Web 2.0 applications are becoming more popular among the digital generation, there is still no evidence of students' perceptions of adopting the innovation of Web 2.0 technologies in Kuwait. The problem this study addresses is that the current status of Web 2.0 technologies usage by academic students has remained educationally unknown in Kuwait. Therefore, there was a need to investigate the extent to which academic students in SBE are aware of and their usage of Web 2.0 technologies, as well as the factors and obstacles that affect using these technologies. Rogers' diffusion of innovation theory (DoI) is employed in this study to specify the factors that influence student perceptions of adopting Web 2.0 applications as learning tools. Data used in this dissertation was gathered via a survey instrument from 350 students at the SBE and was statistically analyzed to find out the answers of the research questions. This study identified the low rate of Web 2.0 awareness and adoption by the students. Descriptive statistical analysis, such as mean scores and standard deviation, were used to analyze and conclude the findings. In the rates of awareness and adoption of Web 2.0, this study also identified no statistically significant differences between the groups of all the demographic variables except the academic field. The statistically significant differences were identified between the academic variables before and after recoding the academic fields into 5 groups. A t-test and one-way ANOVA were used to determine the statistical significance. Several factors were examined in the study to identify their influence on the rate of adoption. The factors included the rate of awareness, Rogers' attributes of innovations, and the obstacles to adopt Web 2.0. The multiple linear regression technique was used to find out the percentage of variance that was explained by three groups of predictors. The overall research model explained 49% of the variance on the rate of adoption. The implications of the findings, in addition to adding empirical evidence to the body of knowledge, highlight areas for professional development, educational and institutional changes and possibility for future research. digital.library.unt.edu/ark:/67531/metadc67955/
Modeling Synergistic Relationships Between Words and Images
Texts and images provide alternative, yet orthogonal views of the same underlying cognitive concept. By uncovering synergistic, semantic relationships that exist between words and images, I am working to develop novel techniques that can help improve tasks in natural language processing, as well as effective models for text-to-image synthesis, image retrieval, and automatic image annotation. Specifically, in my dissertation, I will explore the interoperability of features between language and vision tasks. In the first part, I will show how it is possible to apply features generated using evidence gathered from text corpora to solve the image annotation problem in computer vision, without the use of any visual information. In the second part, I will address research in the reverse direction, and show how visual cues can be used to improve tasks in natural language processing. Importantly, I propose a novel metric to estimate the similarity of words by comparing the visual similarity of concepts invoked by these words, and show that it can be used further to advance the state-of-the-art methods that employ corpus-based and knowledge-based semantic similarity measures. Finally, I attempt to construct a joint semantic space connecting words with images, and synthesize an evaluation framework to quantify cross-modal semantic relationships that exist between arbitrary pairs of words and images. I study the effectiveness of unsupervised, corpus-based approaches to automatically derive the semantic relatedness between words and images, and perform empirical evaluations by measuring its correlation with human annotators. digital.library.unt.edu/ark:/67531/metadc177223/
Modeling the chemical and photophysical properties of gold complexes.
Various gold complexes were computationally investigated, to probe their photophysical, geometric, and bonding properties. The geometry of AuI complexes (ground state singlet) is very sensitive to the electronic nature of the ligands: σ-donors gave a two-coordinate, linear shape; however, σ-acceptors yielded a three-coordinate, trigonal planar geometry. Doublet AuIIL3 complexes distort to T-shape, and are thus ground state models of the corresponding triplet AuIL3. The disproportionation of AuIIL3 to AuIL3 and AuIIIL3 is endothermic for all ligands investigated, however, σ-donors are better experimental targets for AuII complexes. For dimeric AuI complexes, only one gold center in the optimized triplet exciton displays a Jahn-Teller distortion, and the Au---Au distance is reduced versus the ground state distance (i.e., two reasons for large Stokes' shifts). digital.library.unt.edu/ark:/67531/metadc4640/
Modeling the Effects of Chronic Toxicity of Pharmaceutical Chemicals on the Life History Strategies of Ceriodaphnia Dubia: a Multigenerational Study
Trace quantities of pharmaceuticals (including carbamazepine and sertraline) are continuously discharged into the environment, which causes concern among scientists and regulators regarding their potential long-term impacts on aquatic ecosystems. These compounds and their metabolites are continuously interacting with the orgranisms in various life stages, and may differentially influence development of embryo, larvae, juvenile, and adult stages. To fully understand the potential ecological risks of two candidate pharmaceutical chemicals (carbamazepine (CBZ) and sertraline (SERT)) exposure on survival, growth and reproduction of Ceriodaphnia dubia in three sucessive generations under static renewal toxicity test, a multigenerational approach was taken. Results indicate that SERT exposure showed higher sensitivity to chronic exposure to C. dubia growth and reproduction than CBZ exposure. The lowest concentration to affect fecundity and growth was at 50 µg L-1 SERT in the first two generations. These parameters become more sensitive during the third generation where the LOEC was 4.8 µg L-1. The effective concentrations (EC50) for the number of offspring per female, offspring body size, and dry weight were 17.2, 21.2, and 26.2 µg SERT L-1, respectively. Endpoints measured in this study demonstrate that chronic exposure of C. dubia to SERT leads to effects that occur at concentrations an order of magnitude higher than predicted environmental concentrations indicating potential transgenerationals effects. Additionally, a process-based dynamic energy budget (DEB) model is implemented to predict the simulated effects of chronic toxicity of SERT and CBZ to C. dubia individual behavior at laboratory condition. The model‘s output indicates the ecotoxicological mode of action of SERT exposure, which acts on feeding or assimilation with an effect that rapidly saturates at higher concentrations. Offspring size decreases with the toxic effects on feeding, and offspring number is thus less affected than total investment in reproduction. Consequently, CBZ affects direclty in reproduction which are captured by DEBtox model as increased embryonic hazard and reproduction cost as well as growth and maintenance costs. Furthermore, stress factor linearly increased not only with increasing chemical concentrations but also with exposure time. The DEBtox model establishes a cumulative life history consequence of multigenerational exposure to CBZ and SERT. This approach provides a tool to which to understand the effect of chemical to the individual organism and predict the population level effects in ecological risk assessment of the emerging contaminants. digital.library.unt.edu/ark:/67531/metadc407771/
Modeling the Impact and Intervention of a Sexually Transmitted Disease: Human Papilloma Virus
Many human papilloma virus (HPV) types are sexually transmitted and HPV DNA types 16, 18, 31, and 45 account for more than 75% if all cervical dysplasia. Candidate vaccines are successfully completing US Federal Drug Agency (FDA) phase III testing and several drug companies are in licensing arbitration. Once this vaccine become available it is unlikely that 100% vaccination coverage will be probable; hence, the need for vaccination strategies that will have the greatest reduction on the endemic prevalence of HPV. This thesis introduces two discrete-time models for evaluating the effect of demographic-biased vaccination strategies: one model incorporates temporal demographics (i.e., age) in population compartments; the other non-temporal demographics (i.e., race, ethnicity). Also presented is an intuitive Web-based interface that was developed to allow the user to evaluate the effects on prevalence of a demographic-biased intervention by tailoring the model parameters to specific demographics and geographical region. digital.library.unt.edu/ark:/67531/metadc5289/