Access
Resource Type
Degree Department
Department of Psychology
45
College of Music
42
Department of History
26
Department of Counseling and Higher Education
24
Department of Teacher Education and Administration
23
Department of Biological Sciences
20
Department of Chemistry
17
Department of English
16
Department of Electrical Engineering
15
Department of Sociology
15
48 More
Degree Discipline
Degree Level
Country
Year
Month
Language
493 Matching Results
Results open in a new window/tab.
Results:
1 - 24 of
493
next
Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University
Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free …
Date:
December 31, 2011
Creator:
Wang, Guimei
System:
The UNT Digital Library
Bulk gold catalyzed oxidation reactions of amines and isocyanides and iron porphyrin catalyzed N-H and O-H bond insertion/cyclization reactions of diamines and aminoalcohols
This work involves two projects. The first project entails the study of bulk gold as a catalyst in oxidation reactions of isocyanides and amines. The main goal of this project was to study the activation and reactions of molecules at metal surfaces in order to assess how organometallic principles for homogeneous processes apply to heterogeneous catalysis. Since previous work had used oxygen as an oxidant in bulk gold catalyzed reactions, the generality of gold catalysis with other oxidants was examined. Amine N-oxides were chosen for study, due to their properties and use in the oxidation of carbonyl ligands in organometallic complexes. When amine N-oxides were used as an oxidant in the reaction of isocyanides with amines, the system was able to produce ureas from a variety of isocyanides, amines, and amine N-oxides. In addition, the rate was found to generally increase as the amine N-oxide concentration increased, and decrease with increased concentrations of the amine. Mechanistic studies revealed that the reaction likely involves transfer of an oxygen atom from the amine N-oxide to the adsorbed isocyanide to generate an isocyanate intermediate. Subsequent nucleophilic attack by the amine yields the urea. This is in contrast to the bulk gold-catalyzed reaction mechanism …
Date:
December 29, 2011
Creator:
Klobukowski, Erik
System:
The UNT Digital Library
Charge Transfer and Support Effects in Heterogeneous Catalysis
The kinetic, electronic and spectroscopic properties of two‐dimensional oxide‐supported catalysts were investigated in order to understand the role of charge transfer in catalysis. Pt/TiO{sub 2} nanodiodes were fabricated and used as catalysts for hydrogen oxidation. During the reaction, the current through the diode, as well as its I‐V curve, were monitored, while gas chromatography was used to measure the reaction rate. The current and the turnover rate were found to have the same temperature dependence, indicating that hydrogen oxidation leads to the non‐adiabatic excitation of electrons in Pt. A fraction of these electrons have enough energy to ballistically transport through Pt and overcome the Schottky barrier at the interface with TiO{sub 2}. The yield for this phenomenon is on the order of 10{sup ‐4} electrons per product molecule formed, similar to what has been observed for CO oxidation and for the adsorption of many different molecules. The same Pt/TiO{sub 2} system was used to compare currents in hydrogen oxidation and deuterium oxidation. The current through the diode under deuterium oxidation was found to be greater than under hydrogen oxidation by a factor of three. Weighted by the difference in turnover frequencies for the two isotopes, this would imply a chemicurrent …
Date:
December 21, 2011
Creator:
Hervier, Antoine
System:
The UNT Digital Library
Gas atomized precursor alloy powder for oxide dispersion strengthened ferritic stainless steel
Gas atomization reaction synthesis (GARS) was employed as a simplified method for producing precursor powders for oxide dispersion strengthened (ODS) ferritic stainless steels (e.g., Fe-Cr-Y-(Ti,Hf)-O), departing from the conventional mechanical alloying (MA) process. During GARS processing a reactive atomization gas (i.e., Ar-O{sub 2}) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 150 nm) metastable Cr-enriched oxide layer that was used as a vehicle for solid-state transport of O into the consolidated microstructure. In an attempt to better understand the kinetics of this GARS reaction, theoretical cooling curves for the atomized droplets were calculated and used to establish an oxidation model for this process. Subsequent elevated temperature heat treatments, which were derived from Rhines pack measurements using an internal oxidation model, were used to promote thermodynamically driven O exchange reactions between trapped films of the initial Cr-enriched surface oxide and internal Y-enriched intermetallic precipitates. This novel microstructural evolution process resulted in the successful formation of nano-metric Y-enriched dispersoids, as confirmed using high energy X-ray diffraction and transmission electron microscopy (TEM), equivalent to conventional ODS alloys from MA powders. The thermal …
Date:
December 13, 2011
Creator:
Rieken, Joel
System:
The UNT Digital Library
Imaging gene expression in real-time using aptamers
Signal transduction pathways are usually activated by external stimuli and are transient. The downstream changes such as transcription of the activated genes are also transient. Real-time detection of promoter activity is useful for understanding changes in gene expression, especially during cell differentiation and in development. A simple and reliable method for viewing gene expression in real time is not yet available. Reporter proteins such as fluorescent proteins and luciferase allow for non-invasive detection of the products of gene expression in living cells. However, current reporter systems do not provide for real-time imaging of promoter activity in living cells. This is because of the long time period after transcription required for fluorescent protein synthesis and maturation. We have developed an RNA reporter system for imaging in real-time to detect changes in promoter activity as they occur. The RNA reporter uses strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags), which can be expressed from a promoter of choice. The tobramycin, neomycin and PDC RNA aptamers have been utilized for this system and expressed in yeast from the GAL1 promoter. The IMAGEtag RNA kinetics were quantified by RT-qPCR. In yeast precultured in raffinose containing media the GAL1 promoter responded faster …
Date:
December 13, 2011
Creator:
Shin, Il Chung
System:
The UNT Digital Library
Precision Measurement of Neutrino Oscillation Parameters with KamLAND
This dissertation describes a measurement of the neutrino oscillation parameters #1;{Delta}m{sup 2}{sub 21}, &#952;{sub 12} and constraints on &#952;{sub 13} based on a study of reactor antineutrinos at a baseline of &#8764; 180 km with the KamLAND detector. The data presented here was collected between April 2002 and November 2009, and amounts to a total exposure of 2.64 � 0.07 � 10{sup 32} proton-years. For this exposure we expect 2140 � 74(syst) antineutrino candidates from reactors, assuming standard model neutrino behavior, and 350�88(syst) candidates from background. The number observed is 1614. The ratio of background-subtracted candidates observed to expected is (N{sub Obs} &#8722; N{sub Bkg})/N{sub Exp} = 0.59 � 0.02(stat) � 0.045(syst) which confirms reactor neutrino disappearance at greater than 5&#963; significance. Interpreting this deficit as being due to neutrino oscillation, the best-fit oscillation parameters from a three-flavor analysis are #1;{Delta}m{sup 2}{sub 21} = 7.60{sup +0.20}{sub &#8722;0.19}�10{sup &#8722;5}eV{sup 2}, &#952;{sub 12} = 32.5 � 2.9 degrees and sin{sup 2} &#952;{sub 13} = 0.025{sup +0.035}{sub &#8722;0.035}, the 95% confidence-level upper limit on sin{sup 2} &#952;{sub 13} is sin{sup 2} &#952;{sub 13} < 0.083. Assuming CPT invariance, a combined analysis of KamLAND and solar neutrino data yields best-fit values: #1;{Delta}m{sup 2}{sub 21} …
Date:
December 12, 2011
Creator:
KamLAND, & O'Donnell, Thomas
System:
The UNT Digital Library
Optically Detected Magnetic Resonance Studies on π-conjugated semiconductor systems
Optically Detected Magnetic Resonance (ODMR) techniques were used to investigate the dynamics of excitons and charge carriers in π-conjugated organic semiconductors. Degradation behavior of the negative spin-1/2 electroluminescence-detected magnetic resonance (ELDMR) was observed in Alq3 devices. The increase in the resonance amplitude implies an increasing bipolaron formation during degradation, which might be the result of growth of charge traps in the device. The same behavior of the negative spin-1/2 ELDMR was observed in 2wt% Rubrene doped Tris(8-hydroxyquinolinato)aluminium (Alq3) devices. However, with increasing injection current, a positive spin-1/2 ELDMR, together with positive spin 1 triplet powder patterns at {delta}m{sub S}={+-}1 and {delta}m{sub S}={+-}2, emerges. Due to the similarities in the frequency dependences of single and double modulated ELDMR and the photoluminescence-detected magnetic resonance (PLDMR) results in poly[2-methoxy-5-(2 -ethyl-hexyloxy)-1,4-phenyl ene vinylene] (MEH-PPV) films, the mechanism for this positive spin-1/2 ELDMR was assigned to enhanced triplet-polaron quenching under resonance conditions. The ELDMR in rubrene doped Alq3 devices provides a path to investigate charge distribution in the device under operational conditions. Combining the results of several devices with different carrier blocking properties and the results from transient EL, it was concluded trions not only exist near buffer layer but also exist in the electron …
Date:
December 6, 2011
Creator:
Chen, Ying
System:
The UNT Digital Library
ADHD Symptomology and Overweight Among College Men
Attention deficit/hyperactivity disorder (ADHD) is a childhood disorder that often persists into adulthood. Among adults, ADHD is highly comorbid with addictive behaviors (e.g., substance abuse and dependence), and depressive disorders. Recently, an association between ADHD and obesity has been reported in the literature; emotional and binge eating may be “addictive behaviors” that contribute to weight gain in this population. The purpose of this study was to test competing models of the hypothesized link between ADHD symptomology and overweight. Specifically, in Model 1, symptoms of depression are expected to mediate the relationship between symptoms of impulsivity and inattention and emotional and binge eating which, in turn, leads to weight gain (i.e., increased BMI). In Model 2, however, the impulsive symptoms have direct relationships with emotional and binge eating in addition to being mediated by depressive symptoms. Structural equation modeling (SEM) was employed to test how the models fit the data of 790 college men. Both models fit the data well, with Model 2 being preferred because of its greater connection to theory. All paths were significant indicating that increased impulsive and inattentive symptoms predicted increased symptoms of depression that, in turn, predicted increased emotional/binge eating, which has a direct and positive …
Date:
December 2011
Creator:
Johnson, Leslee M.
System:
The UNT Digital Library
Anti-bullying Policies And Practices In Texas Middle Schools
For over a decade national attention to bullying in American schools has increased, fueled by publicity about suicides of severely bullied youth. Schools have the charge of maintaining the safety of all students in order to ensure a positive learning environment, but there is little information about what they are doing to prevent bullying. The purpose of this study was to provide information on principals’ perceptions of bullying and what anti-bullying policies, procedures, and programs exist in Texas middle schools. Ninety-nine principals completed an online questionnaire that addressed: 1) their knowledge of district and campus policies concerning bullying; 2) their direct experience with bullying; and, 3) bullying-prevention strategies and training in place in their schools. Principals reported direct experience with all types of bullying included on the questionnaire in their schools, but had a surprisingly small mean of 14.8 verified bullying incidents during the 2010-2011 year. Over 60% felt the level of physical safety in their school was good or very good, but only 35% rated their school’s emotional safety as good or very good. Students, parents, and teachers reported bullying to the majority of principals; however, few schools conducted annual student surveys that could provide accurate information about bullying …
Date:
December 2011
Creator:
Robbins, Rosemary
System:
The UNT Digital Library
Arithmetic Computations and Memory Management Using a Binary Tree Encoding af Natural Numbers
Two applications of a binary tree data type based on a simple pairing function (a bijection between natural numbers and pairs of natural numbers) are explored. First, the tree is used to encode natural numbers, and algorithms that perform basic arithmetic computations are presented along with formal proofs of their correctness. Second, using this "canonical" representation as a base type, algorithms for encoding and decoding additional isomorphic data types of other mathematical constructs (sets, sequences, etc.) are also developed. An experimental application to a memory management system is constructed and explored using these isomorphic types. A practical analysis of this system's runtime complexity and space savings are provided, along with a proof of concept framework for both applications of the binary tree type, in the Java programming language.
Date:
December 2011
Creator:
Haraburda, David
System:
The UNT Digital Library
Assessment of Transportation Emissions for Ferrous Scrap Exports from the United States: Activity-Based Maritime Emissions Model and Theoretical Inland Transportation Model.
Industrial ecology is a field of study that encourages the use of closed-loop material cycles to achieve sustainability. Loop closing requires the movement of materials over space, and has long been practiced in the iron and steel industry. Iron and steel (ferrous) scrap generated in the U.S. is increasingly exported to countries in Asia, lengthening the transportation distance associated with closing the loop on the iron and steel life cycle. In order to understand the environmental cost of transporting this commodity, an activity-based maritime transportation model and a theoretical in-land transportation model are used to estimate emissions generated. Results indicate that 10.4 mmt of total emissions were generated, and emissions increased by 136 percent from 2004 to 2009. Increases in the amount of emissions generated are due to increases in the amount of scrap exported and distance it is transported.
Date:
December 2011
Creator:
Caldwell, Amanda
System:
The UNT Digital Library
Baroque Elements In The Piano Sonata, Opus 9 By Paul Creston
Paul Creston (1906-1985) was one of the most significant American composers from the middle of the twentieth century. Though Creston maintained elements of the nineteenth-century Romantic tradition and was categorized as a “Neo-Romantic” or “20th-century traditionalist,” many of Creston’s compositions contain elements of Baroque music. His Piano Sonata, Opus 9 provides significant examples of Baroque elements, while already foreshadowing his mature style. The purpose of this study is to explore Baroque elements in the compositional language of Paul Creston’s Piano Sonata, Opus 9. All four movements of the Piano Sonata will be examined in regards to its stylistic features associated with Baroque practices. These features mainly consist of rhythm, texture, imitative writing, and repeated phrase structure. Each category of the study will include comparisons of Domenico Scarlatti’s keyboard sonatas with Creston’s sonata. Through an examination of the Piano Sonata and its Baroque elements, this study hopes to inspire renewed interest in the work among musicians and to help the performer give a more stylistically coherent, and accurate, performance.
Date:
December 2011
Creator:
Watanabe, Chie
System:
The UNT Digital Library
Benthic Macroinvertebrates of Temperate, Sub-Antarctic Streams: The Effects of Altitudinal Zoning and Temperature on the Phenology of Aquatic Insects Associated to the Robalo River, Navarino Island (55°S), Chile
The Cape Horn Biosphere Reserve, within the remote Sub-Antarctic ecoregion is a reservoir of expressions of biological and cultural diversity. Although it is considered one of 24 wilderness areas remaining in the world, it is not free from local and global threats, such as invasive species, and climate change. Field biologists and philosophers associated to the Sub-Antarctic Biocultural Conservation Program and the Omora Ethnobotanical Park, have worked to describe the region’s biocultural diversity, linking ecological and philosophical research into education, ecotourism, and conservation, through a methodology called field environmental philosophy (FEP), which integrates ecological sciences and environmental ethics through a 4-step cycle consisting of: 1) interdisciplinary research; 2) composition of metaphors; 3) design of field activities with an ecological and ethical orientation; and 4) implementation of in situ conservation areas. In this context, the purposes of this dissertation were to: 1) provide a comprehensive review of publications regarding the conservation status of aquatic and terrestrial insects at a global scale and with an emphasis in southern South America; 2) study the distribution of benthic macroinvertebrates through the sharp altitudinal gradient of the Róbalo River watershed; 3) describe the life histories of Gigantodax sp (Simuliidae: Diptera) and Meridialaris chiloeense (Leptophlebiidae: Ephemeroptera) …
Date:
December 2011
Creator:
Contador Mejías, Tamara Andrea
System:
The UNT Digital Library
Biodegradable Poly(hydroxy Butyrate-co-valerate) Nanocomposites And Blends With Poly(butylene Adipate-co-terephthalate) For Sensor Applications
The utilization of biodegradable polymers is critical for developing “cradle to cradle” mindset with ecological, social and economic consequences. Poly(hydroxy butyrate-co-valerate) (PHBV) shows significant potential for many applications with a polypropylene equivalent mechanical performance. However, it has limitations including high crystallinity, brittleness, small processing window, etc. which need to be overcome before converting them into useful products. Further the development of biodegradable strain sensing polymer sensors for structural health monitoring has been a growing need. In this dissertation I utilize carbon nanotubes as a self sensing dispersed nanofiller. The impact of its addition on PHBV and a blend of PHBV with poly(butylene adipate-co-terephthalate) (PBAT) polymer was examined. Nanocomposites and blends of PHBV, PBAT, and MWCNTs were prepared by melt-blending. The effect of MWCNTs on PHBV crystallinity, crystalline phase, quasi-static and dynamic mechanical property was studied concurrently with piezoresistive response. In PHBV/PBAT blends a rare phenomenon of melting point elevation by the addition of low melting point PBAT was observed. The blends of these two semicrystalline aliphatic and aromatic polyesters were investigated by using differential scanning calorimetry, small angle X-ray scattering, dynamic mechanical analysis, surface energy measurement by contact angle method, polarized optical and scanning electron microscopy, and rheology. The study …
Date:
December 2011
Creator:
Vidhate, Shailesh
System:
The UNT Digital Library
Biodiversity Loss, the Motivation Problem, and the Future of Conservation Education in the United States
The purpose of this dissertation is to make sense of two sets of reactions. On the one hand, Americans can barely lift a finger to help threatened and endangered species while on the other, they routinely come to the aid of human victims of disaster. I argue that in contrast to cases of human tragedy, for the biodiversity crisis conservationists are faced not only with the familiar yet arduous task of motivating the American public to care for living other-than-humans, but they are also saddled with having to overcome the motivation problem of future ethics. The motivation problem consists in eliminating or bridging a motivational gap that lies between knowledge of the effects of our actions on future generations and action taken based upon such knowledge. The gap exists because motives that typically move people to action are either ineffective or unavailable. What is more, the gap influences not only our ability to care for future humans, but it affects our ability to care for future other-than-humans as well. Biodiversity loss is in fact a subset of the problem of future generations, an identification hitherto little appreciated. I argue that conservationists can overcome the motivational gap not by appealing directly …
Date:
December 2011
Creator:
Grove-Fanning, William
System:
The UNT Digital Library
Al-Ca and Al-Fe metal-metal composite strength, conductivity, and microstructure relationships
Deformation processed metal-metal composites (DMMC’s) are composites formed by mechanical working (i.e., rolling, swaging, or wire drawing) of two-phase, ductile metal mixtures. Since both the matrix and reinforcing phase are ductile metals, the composites can be heavily deformed to reduce the thickness and spacing of the two phases. Recent studies have shown that heavily drawn DMMCs can achieve anomalously high strength and outstanding combinations of strength and conductivity. In this study, Al-Fe wire composite with 0.07, 0.1, and 0.2 volume fractions of Fe filaments and Al-Ca wire composite with 0.03, 0.06, and 0.09 volume fractions of Ca filaments were produced in situ, and their mechanical properties were measured as a function of deformation true strain. The Al-Fe composites displayed limited deformation of the Fe phase even at high true strains, resulting in little strengthening effect in those composites. Al-9vol%Ca wire was deformed to a deformation true strain of 13.76. The resulting Ca second-phase filaments were deformed to thicknesses on the order of one micrometer. The ultimate tensile strength increased exponentially with increasing deformation true strain, reaching a value of 197 MPa at a true strain of 13.76. This value is 2.5 times higher than the value predicted by the rule …
Date:
December 1, 2011
Creator:
Kim, Hyong June
System:
The UNT Digital Library
Can Social Disorganization and Social Capital Factors Help Explain the Incidences of Property Crimes in Turkey?
Organized crime and terrorism taking place in the Turkish provinces get more attention in the public agenda than other type of crimes. Although property crimes receive less attention, they pose a serious threat to public order and the social welfare of Turkish society. Academic researchers have also paid little attention to the analysis of property crimes at the macro level in Turkey. For these reasons, this study focused on the analysis of property crimes for three years period, 2005, 2006 and 2007 in Turkey, using a conceptual model of social disorganization. Provincial level data from Turkish governmental agencies were used. The findings of multivariate analyses showed that social disorganization approach, as measured in this study, provided a partial explanation of property crime rates in Turkey. Family disruption and urbanization had significant effects on property crime rate, while remaining exogenous elements of social disorganization (i.e., SES, population heterogeneity and residential mobility) did not have any expected effects. In mediation analysis, using faith-based engagement and political participation rates as mediators between the structural factors of social disorganization and property crime rate provided marginal support for the theory. Political participation rate partially mediated the relationship between property crime rate and urbanization rate, while …
Date:
December 2011
Creator:
Irmak, Fatih
System:
The UNT Digital Library
A Characterization Of Jackson Blue Spring, Jackson County, Florida
Jackson Blue is a first magnitude spring in the karst terrane of northeast Florida. Previous studies have identified inorganic fertilizer as the source of high nitrate levels in the spring. Agricultural land use and karst vulnerability make Jackson Blue a good model for conservation concerns. This work offers an aggregation of studies relating to the springshed, providing a valuable tool for planning and conservation efforts in the region. An analysis of nitrate levels and other water quality parameters within the springshed did not reveal significantly different values between agricultural and forested land use areas. Confounding factors include: high transmissivity in the aquifer, interspersed land use parcels, and fertilizer application in forested areas due to commercial pine stand activity.
Date:
December 2011
Creator:
Reiser, Cora
System:
The UNT Digital Library
The Chopin Etudes: a Study Guide for Teaching and Learning Opus 10 and Opus 25
The etudes of Chopin are masterworks of the piano literature and are designed to go beyond mere technical exercises; moreover, each etude represents not only a technical study but also has a distinct musical character. Alarmingly, the current trend seems to be to assign the Chopin etudes at an increasingly young age to students who are not yet equipped either technically or musically to handle them. As Chopin’s pupil, Carl Mikuli, commented in the preface to his Chopin edition, the etudes were meant for “more advanced students.” If Chopin had intended his etudes for students at an intermediate level, he would have assigned them to most of his students; however, only a limited number of students had his permission to work on their master’s etudes. As a teacher, I have always felt the need to devise a systematic teaching plan to guide students to handle the challenges of these pieces both physically and musically. This study examines the repertoire which might help prepare a student to learn the etudes without overstraining his/her muscular and mental ability. Rooted in Chopin’s teaching and his recommendation of the pieces to learn before tackling the etudes themselves, this pedagogical study guide intends to help …
Date:
December 2011
Creator:
Kim, Min Joung
System:
The UNT Digital Library
Communication System over Gnu Radio and OSSIE
GNU Radio and OSSIE (Open-Source SCA (Software communication architecture) Implementation-Embedded) are two open source software toolkits for SDR (Software Defined Radio) developments, both of them can be supported by USRP (Universal Software Radio Peripheral). In order to compare the performance of these two toolkits, an FM receiver over GNU Radio and OSSIE are tested in my thesis, test results are showed in Chapter 4 and Chapter 5. Results showed that the FM receiver over GNU Radio has better performance, due to the OSSIE is lack of synchronization between USRP interface and the modulation /demodulation components. Based on this, the SISO (Single Input Single Output) communication system over GNU Radio is designed to transmit and receive sound or image files between two USRP equipped with RFX2400 transceiver at 2.45G frequency. Now, GNU Radio and OSSIE are widely used for academic research, but the future work based on GNU Radio and OSSIE can be designed to support MIMO, sensor network, and real time users etc.
Date:
December 2011
Creator:
Cheng, Zizhi
System:
The UNT Digital Library
Comparative Analysis Of 105 Higher Education Doctoral Programs In The United States
The mission types of 105 current doctoral programs in higher education and the extent to which their missions have changed since a similar study was conducted by Dressel and Mayhew in 1974 was studied. The curricula offerings of these programs by degree type (e.g., Ed.D. & Ph.D.) were compared with Fife’s 1991 findings. Finally, the study examined the various modes of instruction (e.g., classroom, online, cohort, blended) these programs utilize. The population was the 131 U.S. higher education doctoral program coordinators or directors who were identified using the ASHE Higher Education Program Directory. A total of 46 hosted Ed.D. programs and 59 hosted Ph.D. programs for a combined total of 105 doctoral programs. An electronic survey, developed by utilizing an expert panel and the cognitive interviewing technique, was sent to each participant. A total of 46 hosted Ed.D. programs and 59 hosted Ph.D. programs for a combined total of 105 doctoral programs. A total of 77 institutions (59%) returned usable questionnaires, and six other universities (5%) indicated their doctoral higher education programs no longer existed. Twenty-three of the responding institutions identified with a research-focused mission; 25 institutions identified with a practitioner-based mission; and 28 institutions identified with both types of …
Date:
December 2011
Creator:
Valerin, Marcus P.
System:
The UNT Digital Library
Comparing Latent Dirichlet Allocation and Latent Semantic Analysis as Classifiers
In the Information Age, a proliferation of unstructured text electronic documents exists. Processing these documents by humans is a daunting task as humans have limited cognitive abilities for processing large volumes of documents that can often be extremely lengthy. To address this problem, text data computer algorithms are being developed. Latent Semantic Analysis (LSA) and Latent Dirichlet Allocation (LDA) are two text data computer algorithms that have received much attention individually in the text data literature for topic extraction studies but not for document classification nor for comparison studies. Since classification is considered an important human function and has been studied in the areas of cognitive science and information science, in this dissertation a research study was performed to compare LDA, LSA and humans as document classifiers. The research questions posed in this study are: R1: How accurate is LDA and LSA in classifying documents in a corpus of textual data over a known set of topics? R2: How accurate are humans in performing the same classification task? R3: How does LDA classification performance compare to LSA classification performance? To address these questions, a classification study involving human subjects was designed where humans were asked to generate and classify documents …
Date:
December 2011
Creator:
Anaya, Leticia H.
System:
The UNT Digital Library
The Compositional Transformation and Musical Rebirth of Leo Ornstein
This study focuses on the transformation of Leo Ornstein’s (1893-2002) musical language of his early years into the strikingly different approach found in his later years. Ornstein’s initial radical compositions from the mid-1910s were no doubt representative of the direction in which modern music was moving. Despite the intense fame and notoriety of his early works, Ornstein did not feel connected to the trends of modern music development, and by the end of the 1930s he withdrew from the public scene and turned to teaching. By the 1950s Ornstein had been almost forgotten, and in later life he became a very private person. He worked in almost total isolation composing a substantial amount of music well into his nineties, and died at the age of 109. The music of Ornstein’s “second life” is very different from the initial works of his early years, and most of it is unknown to the public and should be brought into scholarly light, especially since Ornstein has been considered by historians as a pivotal figure in twentieth-century music. This study examines selected music from different stages of Ornstein’s career: Wild Men’s Dance (1913), Suicide in an Airplane (1913), Arabesques (1918), A Long Remembered Sorrow …
Date:
December 2011
Creator:
Bonney, Michael
System:
The UNT Digital Library
The Concept Of “Unity” In Isang Yun’s Königliches Thema Fr Violine Solo
A Korean-German composer Isang Yun.s life was evenly distributed between two different countries, and his music contains both elements of performance practices of Eastern Asian and Western music. This dissertation presents his ethnic and aesthetic musical roots by an analytic examination of his solo violin piece, K♠nigliches Thema (1976). The dissertation is divided into four chapters. The first chapter contains Isang Yuns biography and his works of the four periods. The second chapter studies his philosophy in music and compositional techniques such as twelve-tone technique, Taoism, Hauptton, Hauptklang and the Korean instrumental technique in Western instruments. The third chapter presents a detailed analysis of Knigliches Thema with his Taoist philosophy. The fourth chapter is solely dedicated to the performance perspectives of Königliches Thema in tempo, dynamic and various violin techniques.
Date:
December 2011
Creator:
Kim, Songyoung
System:
The UNT Digital Library