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Uncovering the single top: observation of electroweak top quark production (open access)

Uncovering the single top: observation of electroweak top quark production

The top quark is generally produced in quark and anti-quark pairs. However, the Standard Model also predicts the production of only one top quark which is mediated by the electroweak interaction, known as 'Single Top'. Single Top quark production is important because it provides a unique and direct way to measure the CKM matrix element V{sub tb}, and can be used to explore physics possibilities beyond the Standard Model predictions. This dissertation presents the results of the observation of Single Top using 2.3 fb{sup -1} of Data collected with the D0 detector at the Fermilab Tevatron collider. The analysis includes the Single Top muon+jets and electron+jets final states and employs Boosted Decision Tress as a method to separate the signal from the background. The resulting Single Top cross section measurement is: (1) {sigma}(p{bar p} {yields} tb + X, tqb + X) = 3.74{sub -0.74}{sup +0.95} pb, where the errors include both statistical and systematic uncertainties. The probability to measure a cross section at this value or higher in the absence of signal is p = 1.9 x 10{sup -6}. This corresponds to a standard deviation Gaussian equivalence of 4.6. When combining this result with two other analysis methods, the resulting …
Date: August 1, 2009
Creator: Benitez, Jorge Armando
System: The UNT Digital Library
Search for charged Higgs bosons in decays of top quarks in proton - antiproton collisions at s**(1/2) = 1.96 TeV (open access)

Search for charged Higgs bosons in decays of top quarks in proton - antiproton collisions at s**(1/2) = 1.96 TeV

In this dissertation we report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses a data sample with an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector at Fermilab and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays; hence 95% C.L. upper limits on the branching ratio are placed at {Beta}(t {yields} H{sup +}b) < 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c{sup 2} assuming {Beta}(H{sup +} {yields} c{bar s}) = 1.0 and {Beta}(t {yields} Wb)+{Beta}(t {yields} H{sup +}b) = 1.0. The upper limits on {Beta}(t {yields} H{sup +}b) are also used as model independent limits on the decay branching ratio of top quarks to any charged scalar bosons beyond the standard model.
Date: August 1, 2009
Creator: Yu, Geum Bong
System: The UNT Digital Library
From ZZ to ZH : How Low Can These Cross Sections Go or Everybody, Let's Cross Section Limbo! (open access)

From ZZ to ZH : How Low Can These Cross Sections Go or Everybody, Let's Cross Section Limbo!

We report on two searches performed at the D0 detector at the Fermi National Laboratory. The first is a search for Z di-boson production with a theoretical cross section of 1.4 pb. The search was performed on 2.6 fb{sup -1} of data and contributed to the first observation of ZZ production at a hadron collider. The second is a search for a low mass Standard Model Higgs in 4.2 fb{sup -1} of data. The Higgs boson is produced in association with a Z boson where the Higgs decays hadronically and the Z decays to two leptons. The ZZ search was performed in both the di-electron and di-muon channels. For the ZH search, we will focus on the muonic decays where we expanded the traditional coverage by considering events in which one of the two muons fails the selection requirement, and is instead reconstructed as an isolated track. We consider Higgs masses between 100 and 150 GeV, with theoretical cross sections ranging from 0.17 to 0.042 pb, and set upper limits on the ZH production cross-section at 95% confidence level.
Date: August 1, 2009
Creator: Strauss, Emanuel Alexandre
System: The UNT Digital Library
Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry (open access)

Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry

Mass spectrometric methods that are able to analyze solid samples or biological materials with little or no sample preparation are invaluable to science as well as society. Fundamental research that has discovered experimental and instrumental parameters that inhibit fractionation effects that occur during the quantification of elemental species in solid samples by laser ablation inductively coupled plasma mass spectrometry is described. Research that determines the effectiveness of novel laser desorption/ionization mass spectrometric methods for the molecular analysis of biological tissues at atmospheric pressure and at high spatial resolution is also described. A spatial resolution is achieved that is able to analyze samples at the single cell level.
Date: August 19, 2009
Creator: Perdian, David C.
System: The UNT Digital Library
Observation of excited state charge transfer with fs/ps-CARS (open access)

Observation of excited state charge transfer with fs/ps-CARS

Excited state charge transfer processes are studied using the fs/ps-CARS probe technique. This probe allows for multiplexed detection of Raman active vibrational modes. Systems studied include Michler's Ketone, Coumarin 120, 4-dimethylamino-4{prime}-nitrostilbene, and several others. The vibrational spectrum of the para di-substituted benzophenone Michler's Ketone in the first excited singlet state is studied for the first time. It is found that there are several vibrational modes indicative of structural changes of the excited molecule. A combined experimental and theoretical approach is used to study the simplest 7-amino-4-methylcoumarin, Coumarin 120. Vibrations observed in FTIR and spontaneous Raman spectra are assigned using density functional calculations and a continuum solvation model is used to predict how observed modes are affected upon inclusion of a solvent. The low frequency modes of the excited state charge transfer species 4-dimethylamino-4{prime}-nitrostilbene are studied in acetonitrile. Results are compared to previous work on this molecule in the fingerprint region. Finally, several partially completed projects and their implications are discussed. These include the two photon absorption of Coumarin 120, nanoconfinement in cyclodextrin cavities and sensitization of titania nanoparticles.
Date: August 1, 2009
Creator: Blom, Alex Jason
System: The UNT Digital Library
Ion distributions at charged aqueous surfaces: Synchrotron X-ray scattering studies (open access)

Ion distributions at charged aqueous surfaces: Synchrotron X-ray scattering studies

Surface sensitive synchrotron X-ray scattering studies were performed to obtain the distribution of monovalent ions next to a highly charged interface at room temperature. To control surface charge density, lipids, dihexadecyl hydrogen-phosphate (DHDP) and dimysteroyl phosphatidic acid (DMPA), were spread as monolayer materials at the air/water interface, containing CsI at various concentrations. Five decades in bulk concentrations (CsI) are investigated, demonstrating that the interfacial distribution is strongly dependent on bulk concentration. We show that this is due to the strong binding constant of hydronium H3O+ to the phosphate group, leading to proton-transfer back to the phosphate group and to a reduced surface charge. Using anomalous reflectivity off and at the L3 Cs+ resonance, we provide spatial counterion (Cs+) distributions next to the negatively charged interfaces. The experimental ion distributions are in excellent agreement with a renormalized surface charge Poisson-Boltzmann theory for monovalent ions without fitting parameters or additional assumptions. Energy Scans at four fixed momentum transfers under specular reflectivity conditions near the Cs+ L3 resonance were conducted on 10-3 M CsI with DHDP monolayer materials on the surface. The energy scans exhibit a periodic dependence on photon momentum transfer. The ion distributions obtained from the analysis are in excellent agreement …
Date: August 15, 2009
Creator: Bu, Wei
System: The UNT Digital Library
Muon neutrino disappearance at MINOS (open access)

Muon neutrino disappearance at MINOS

A strong case has been made by several experiments that neutrinos oscillate, although important questions remain as to the mechanisms and precise values of the parameters. In the standard picture, two parameters describe the nature of how the neutrinos oscillate: the mass-squared difference between states and the mixing angle. The purpose of this thesis is to use data from the MINOS experiment to precisely measure the parameters associated with oscillations first observed in studies of atmospheric neutrinos. MINOS utilizes two similar detectors to observe the oscillatory nature of neutrinos. The Near Detector, located 1 km from the source, observes the unoscillated energy spectrum while the Far Detector, located 735 km away, is positioned to see the oscillation signal. Using the data in the Near Detector, a prediction of the expected neutrino spectrum at the Far Detector assuming no oscillations is made. By comparing this prediction with the MINOS data, the atmospheric mixing parameters are measured to be {Delta}m{sub 32}{sup 2} = 2.45{sub +0.12}{sup -0.12} x 10{sub -3} eV{sup 2} and sin{sup 2}(2{theta}{sub 32}) = 1.00{sub -0.04}{sup +0.00} (> 0.90 at 90% confidence level).
Date: August 1, 2009
Creator: Armstrong, R.
System: The UNT Digital Library
Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles (open access)

Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content with low viscosity in order to produce a high quality product. The addition of a dispersant is useful so that higher solids content suspensions can be used with lower viscosities. For BECy suspensions, the addition of nanoparticles to the BECy resin is expected to enhance the mechanical properties of the cured composite. The addition of saccharides to aqueous suspensions leads to viscosity reduction. Through DSC measurements it was found that the saccharide molecules formed a solution with water and this resulted in lowering the melting temperature of the free water according to classic freezing point depression. Saccharides also lowered the melting temperature of the bound water, but this followed a different rule. The shear thinning and melting behaviors of the suspensions were used to develop …
Date: August 5, 2009
Creator: Lawler, Katherine
System: The UNT Digital Library
Rational Ligand Design for U(VI) and Pu(IV) (open access)

Rational Ligand Design for U(VI) and Pu(IV)

Nuclear power is an attractive alternative to hydrocarbon-based energy production at a time when moving away from carbon-producing processes is widely accepted as a significant developmental need. Hence, the radioactive actinide power sources for this industry are necessarily becoming more widespread, which is accompanied by the increased risk of exposure to both biological and environmental systems. This, in turn, requires the development of technology designed to remove such radioactive threats efficiently and selectively from contaminated material, whether that be contained nuclear waste streams or the human body. Raymond and coworkers (University of California, Berkeley) have for decades investigated the interaction of biologically-inspired, hard Lewis-base ligands with high-valent, early-actinide cations. It has been established that such ligands bind strongly to the hard Lewis-acidic early actinides, and many poly-bidentate ligands have been developed and shown to be effective chelators of actinide contaminants in vivo. Work reported herein explores the effect of ligand geometry on the linear U(IV) dioxo dication (uranyl, UO{sub 2}{sup 2+}). The goal is to utilize rational ligand design to develop ligands that exhibit shape selectivity towards linear dioxo cations and provides thermodynamically favorable binding interactions. The uranyl complexes with a series of tetradentate 3-hydroxy-pyridin-2-one (3,2-HOPO) ligands were studied in …
Date: August 12, 2009
Creator: Szigethy, Geza
System: The UNT Digital Library
COUPLED MULTI-GROUP NEUTRON PHOTON TRANSPORT FOR THE SIMULATION OF HIGH-RESOLUTION GAMMA-RAY SPECTROSCOPY APPLICATIONS (open access)

COUPLED MULTI-GROUP NEUTRON PHOTON TRANSPORT FOR THE SIMULATION OF HIGH-RESOLUTION GAMMA-RAY SPECTROSCOPY APPLICATIONS

The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples.
Date: August 1, 2009
Creator: Burns, Kimberly A.
System: The UNT Digital Library
God's Perfect Timing (open access)

God's Perfect Timing

When I was thirty-three years old, I discovered I was an adoptee. In this memoir of secrecy and love, betrayal and redemption, I reflect on my early experiences as a doted-on only child firmly rooted in the abundant love of my adoptive family, my later struggles with depression and obsessive-compulsive disorder, my marriage to a fellow-adoptee, my discovery of my own adoption and the subsequent reunion with my birth family, my navigation through the thrills and tensions of newly complicated family dynamics, and my witness to God's perfect timing through it all.
Date: August 2009
Creator: Rizzo, Steven
System: The UNT Digital Library
An Informational Theory of Midterm Elections: The Impact of Iraq War Deaths on the 2006 Election. (open access)

An Informational Theory of Midterm Elections: The Impact of Iraq War Deaths on the 2006 Election.

There has been much scholarly attention directed at the Iraq war's role in determining voter choice. I attempt to extend that research into voter turnout to determine what role the Iraq war played in 2006 voter turnout. This paper argues that turnout at the state level could be explained by the number of US deaths each state had sustained from the Iraq occupation at the time of the election. A theory of voter activation based on information availability is put forth to explain the relationship between national events and voter turnout wherein national events like the Iraq war will raise the amount of information voters have at their disposal, which will increase the likelihood of their voting on election day. Regression analysis comparing the turnout rates of the 50 states to their casualties in Iraq revealed no relationship between the two factors, indicating that something else is responsible for the high turnout of the midterm.
Date: August 2009
Creator: Kahanek, Jared E.
System: The UNT Digital Library
Evaluation of skill maintenance, performance factors, and external validity in a behavioral parent training program. (open access)

Evaluation of skill maintenance, performance factors, and external validity in a behavioral parent training program.

Child maltreatment affects 900 thousand children in the U.S. every year and impacts all areas of daily functioning. Behavioral parent training (BPT) programs have effectively taught parenting and demonstrated externally valid outcomes (i.e., lower recidivism rates). Skill maintenance assessments for BPTs have mixed results. The Behavior Management and Parenting Services (BMAPS) program has shown effective skill training for court-mandated families. This study assessed skill maintenance and performance factors that may have impaired parents using an ABAB single-case research design in Phase 1 & external validity with a survey in Phase 2. Results for Phase 1 found that most BMAPS parents acquired all parenting tools to criteria, dropped below criteria at the 3 month probe, then fully demonstrated their regained skills after a brief review. Psychological and classroom factors do not appear to have systematically influenced performance at any time, although homework completion was associated with better scores at the end of class. Phase 2 results found a 91% reunification rate and a 0% recidivism rate over 1-3 years. All limitations aside, it appears that the BMAPS program is able to effectively train skills to criteria and these skills can be sustained with a booster session. The vast majority of parents …
Date: August 2009
Creator: Scherbarth, Andrew J.
System: The UNT Digital Library
An Introduction to the AIDS Quilt Songbook and Its Uncollected Works (open access)

An Introduction to the AIDS Quilt Songbook and Its Uncollected Works

The AIDS Quilt Songbook was a musical response to the shame surrounding the outbreak of the HIV virus and was one of the first art song publications to deal with the topic of HIV and AIDS. This DMA thesis documents the significance and history of the AIDS Quilt Songbook, traces the progression of the project up until December 1, 2008, and documents the work, experiences, and words of the composers who have been inspired to contribute to the AIDS Quilt Songbook Project. In 1981, the medical and popular press reported the first cases of a quickly spreading virus among homosexual males. This virus is currently diagnosed as HIV and AIDS. Lack of funding consumed the early years of what grew to become a national pandemic. The artistic community was one of the major catalysts for funding and education. Cleave Jones and other gay rights activists developed the NAMES Project as a memoriam for those lost to the pandemic. The AIDS Quilt Songbook was created to parallel the AIDS Quilt as "a never-ending work whose meaning and spirit is renewed and redefined with every addition." This concept of additions has continued the expansion of the AIDS Quilt Songbook Project from 1993 …
Date: August 2009
Creator: Seesholtz, John Clayton
System: The UNT Digital Library
Social Movements, Subjectivity, and Solidarity: Witnessing Rhetoric of the International Solidarity Movement (open access)

Social Movements, Subjectivity, and Solidarity: Witnessing Rhetoric of the International Solidarity Movement

This study engaged in pushing the current political limitations created by the political impasse of the Palestinian-Israeli conflict, by imagining new possibilities for radical political change, agency, and subjectivity for both the international activists volunteering with the International Solidarity Movement as well as Palestinians enduring the brutality of life under occupation. The role of the witness and testimony is brought to bear on activism and rhetoric the social movement ISM in Palestine. Approaches the past studies of the rhetoric of social movements arguing that rhetorical studies often disassociated 'social' from social movements, rendering invisible questions of the social and subjectivity from their frames for evaluation. Using the testimonies of these witnesses, Palestinians and activists, as the rhetorical production of the social movement, this study provides an effort to put the social body back into rhetorical studies of social movements. The relationships of subjectivity and desubjectification, as well as, possession of subjects by agency and the role of the witness with each of these is discussed in terms of Palestinian and activist potential for subjectification and desubjectifiation.
Date: August 2009
Creator: Wachsmann, Emily Brook
System: The UNT Digital Library
Growth and Characterization of β-Iron Disilicide, β-Iron Silicon Germanide, and Osmium Silicides (open access)

Growth and Characterization of β-Iron Disilicide, β-Iron Silicon Germanide, and Osmium Silicides

The semiconducting silicides offer significant potential for use in optoelectronic devices. Full implementation of the materials, however, requires the ability to tailor the energy gap and band structure to permit the synthesis of heterojunctions. One promising approach is to alloy the silicides with Ge. As part of an investigation into the synthesis of semiconducting silicide heterostructures, a series of β-Fe(Si1−xGex)2 epilayer samples, with nominal alloy content in the range 0 < x < 0.15, have been prepared by molecular beam epitaxy on Si(100). I present results of the epitaxial and crystalline quality of the films, as determined by reflection high-energy electron diffraction, Rutherford backscattering spectroscopy, and double crystal x-ray diffraction, and of the band gap dependence on the alloy composition, as determined by Fourier transform infrared spectroscopy. A reduction in band gap was observed with increasing Ge content, in agreement with previous theoretical predictions. However Ge segregation was also observed in β-Fe(Si1−xGex)2 epilayers when x > 0.04. Osmium silicide films have been grown by molecular beam epitaxy on Si(100). The silicides have been grown using e-beam evaporation sources for both Os and Si onto Si(100) substrates at varying growth rates and temperatures ranging from 600-700ºC. The resulting films have been …
Date: August 2009
Creator: Cottier, Ryan James
System: The UNT Digital Library
Francis Poulenc's Sonata for Horn, Trumpet and Trombone: A Structural Analysis Identifying Historical Significance, Form and Implications for Performance (open access)

Francis Poulenc's Sonata for Horn, Trumpet and Trombone: A Structural Analysis Identifying Historical Significance, Form and Implications for Performance

Research has been conducted on Francis Poulenc and his prominent 20th century sonata for brass instruments. Poulenc and members of the French compositional collaboration known as Les Six have all been subjects of research. Francis Poulenc's Sonata for Horn Trumpet and Trombone is a crucial piece in the development of brass chamber music during the 20th century. As one of the first works written for modern brass instruments, it demonstrates a highly crafted compositional style representative of Poulenc's early period. Research includes background and historical significance of the Sonata, analysis of form and compositional techniques, biographical information on Francis Poulenc and the members of Les Six and a section on implications for the performance of the work. This study is necessary due to the lack of research available for the piece especially considering its relevance to the development of brass chamber music. This study explores the compositional style of Francis Poulenc and his contribution to the brass ensemble repertoire.
Date: August 2009
Creator: Cord, John T.
System: The UNT Digital Library
The Impact of IT Capability on Employee Capability, Customer Value, Customer Satisfaction, and Business Performance (open access)

The Impact of IT Capability on Employee Capability, Customer Value, Customer Satisfaction, and Business Performance

This study empirically examines the impact of IT capability on firms' performance and evaluates whether firms' IT capabilities play a role in improving employee capability, customer value, customer satisfaction, and ultimately business performance. The results were based on comparing the business performance of the IT leader companies with that of control companies of similar size and industry. The IT leader companies were selected from the Information Week 500 list published annually from 2001 to 2004. For a company to be selected as IT leaders, it needed to be listed at least twice during the period. Furthermore, it had to be listed in the American Customer Satisfaction Index (ACSI) so that its customer satisfaction level could be assessed. Standard & Poor's Compustat and the ACSI scores were used to test for changes in business performance. The study found that the IT leaders had a raw material cost measured by cost-of-goods-sold to sales ratio (COGS/S) than the control companies. However, it found no evidence that firms' IT capability affects employee capability, customer value, customer satisfaction, and profit. An important implication from this study is that IT becomes a commodity and an attempt to gain a competitive advantage by overinvesting in IT may …
Date: August 2009
Creator: Chae, Ho-Chang
System: The UNT Digital Library
Significant Influences in the Composition of Hendrik Hofmeyr's Song Cycle, Alleenstryd (open access)

Significant Influences in the Composition of Hendrik Hofmeyr's Song Cycle, Alleenstryd

The poet of this cycle, Sydney Vernon Petersen, was a man who faced great adversity during Apartheid. The title of this cycle, Alleenstryd, is an Afrikaans term for 'a struggle alone.' Petersen was of mixed heritage or "Coloured" and born in South Africa in 1914. He died in 1987. His most important works in Afrikaans poetry were published between 1948 and 1965. This cycle specifically focuses on the relationship between the poet and his community, the isolation he endured within that community, the depths of despair he felt and how he overcame those obstacles to finally achieve a sense of self-worth. This group of poems, first published as an anthology by Tafelberg Press in 1979, became the source of inspiration for the composer Hendrik Hofmeyr. The purpose of this research is to identify the significant social, political and musical influences on the composer which contributed to the composition of Alleenstryd (1996), especially the significance of his self-imposed exile. Also, the Afrikaans language, a derivative of 17th century Dutch, is a language dear to its speakers but not widely accessible or familiar to most other nations. Hopefully this research will provide more information and make the language, its composers and the …
Date: August 2009
Creator: Cupido, Conroy Alan
System: The UNT Digital Library
The Parent Participation Discourse of a Community School: Diverse Ideas and Perceptions about Educational Partnership at an Inner City Community School (open access)

The Parent Participation Discourse of a Community School: Diverse Ideas and Perceptions about Educational Partnership at an Inner City Community School

Despite the widespread recommendation that schools "collaborate" with parents, little is found in the literature to elaborate on what this term or the common synonym "partnership" means, and further, how schools can invite diverse parental contributions to the table of educational discourse. The current study looks to contribute to the literature by analyzing the parent participation discourse in one community elementary school, utilizing critical discourse analysis and ethnographic observations. The findings reveal both school and parents' conceptions of the parents' partnership role as ancillary to that of the school's and the subsequent lack of true collaboration so advocated by the literature. Implications arise from this analysis which calls into question the examples of "collaboration" found in the literature, given the lack of theorizing regarding what collaboration inside of parent participation means. Contributions may shed light on the unintentional inequality of diverse parents in an effort toward true collaboration utilizing both the European American, middle class contributions of the educational institution alongside those of non-mainstream parents in creating an authentic educational atmosphere for diverse students.
Date: August 2009
Creator: Coe, Alice Elizabeth
System: The UNT Digital Library
Processing, structure property relationships in polymer layer double hydroxide multifunctional nanocomposites (open access)

Processing, structure property relationships in polymer layer double hydroxide multifunctional nanocomposites

Dan Beaty (1937-2002) was a prolific composer, pianist, researcher, educator, and writer. His large compositional output included chamber works, choral works, songs, orchestral pieces, electronic music, and keyboard works. Beaty was well versed in traditional Western music as well as the more avant-garde and perplexing idioms of the twentieth century. Beaty's compositions reflect the many fascinating, if not always popular, musical trends of his time. His music encompasses styles from serial to jazz, shows compositional influences from Arnold Schoenberg to Indonesian music, and demonstrates thought-provoking and highly intellectual craftsmanship. This document explores several of Beaty's songs through a discussion of the composer's life and compositional process. Songs included in this document are Three Weeks Songs, October, November, A Sappho Lyric, Love Song, That Night When Joy Began, and War Lyrics. This document was written to accompany the author's DMA Lecture-Recital at the University of North Texas. Unfortunately, Beaty's vocal music was never published and is mostly unknown. One goal of the project was to initiate interest in Beaty's songs. Through this document, Lecture-Recital, and additional performances, considerable strides have been made to bring Beaty's songs to new audiences throughout the United States. In addition, the author has received permission from …
Date: August 2009
Creator: Ogbomo, Sunny Minister
System: The UNT Digital Library
Interaction of learning approach with concept integration and achievement in a large guided inquiry organic class. (open access)

Interaction of learning approach with concept integration and achievement in a large guided inquiry organic class.

A study was conducted to investigate the relationship of students' concept integration and achievement with time spent within a topic and across related topics in a large first semester guided inquiry organic chemistry class. Achievement was based on evidence of algorithmic problem solving; and concept integration was based on demonstrated performance explaining, applying, and relating concepts to each other. Twelve individual assessments were made of both variables over three related topics - acid/base, nucleophilic substitution and electrophilic addition reactions. Measurements included written, free response and ordered multiple answer questions using a classroom response system. Results demonstrated that students can solve problems without conceptual understanding. A second study was conducted to compare the students' learning approach at the beginning and end of the course. Students were scored on their preferences for a deep, strategic, or surface approach to learning based on their responses to a pre and post survey. Results suggest that students significantly decreased their preference for a surface approach during the semester. Analysis of the data collected was performed to determine the relationship between students' learning approach and their concept integration and achievement in this class. Results show a correlation between a deep approach and concept integration and a …
Date: August 2009
Creator: Mewhinney, Christina
System: The UNT Digital Library
Transnational Compositionality and Hemon, Shteyngart, Díaz; A No Man's Land, Etc. (open access)

Transnational Compositionality and Hemon, Shteyngart, Díaz; A No Man's Land, Etc.

Contemporary transnational literature presents a unique interpretive problem, due to new methods of language and culture negotiation in the information age. The resulting condition, transnational compositionality, is evidenced by specific linguistic artifacts; to illustrate this I use three American novels as a case study: Nowhere Man by Aleksandar Hemon, Absurdistan by Gary Shteyngart, and The Brief Wondrous Life of Oscar Wao by Junot Díaz. By extension, many conventional literary elements are changed in the transnational since modernity: satire is no longer a lampooning of cultures but a questioning of the methods by which humans blend cultures together; similarly, complex symbolic constructions may no longer be taken at face value, for they now communicate more about cultural identity processes than static ideologies. If scholars are to achieve adequate interpretations of these elements, we must consider the global framework that has so intimately shaped them in the twenty-first century.
Date: August 2009
Creator: Miner, Joshua D.
System: The UNT Digital Library
Study of the effects of background and motion camera on the efficacy of Kalman and particle filter algorithms. (open access)

Study of the effects of background and motion camera on the efficacy of Kalman and particle filter algorithms.

This study compares independent use of two known algorithms (Kalmar filter with background subtraction and Particle Filter) that are commonly deployed in object tracking applications. Object tracking in general is very challenging; it presents numerous problems that need to be addressed by the application in order to facilitate its successful deployment. Such problems range from abrupt object motion, during tracking, to a change in appearance of the scene and the object, as well as object to scene occlusions, and camera motion among others. It is important to take into consideration some issues, such as, accounting for noise associated with the image in question, ability to predict to an acceptable statistical accuracy, the position of the object at a particular time given its current position. This study tackles some of the issues raised above prior to addressing how the use of either of the aforementioned algorithm, minimize or in some cases eliminate the negative effects
Date: August 2009
Creator: Morita, Yasuhiro
System: The UNT Digital Library