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  Access Rights: Use restricted to UNT Community
 Decade: 2010-2019
 Degree Level: Master's
 Collection: UNT Theses and Dissertations
Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

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Date: August 2013
Creator: Fogueri, Uma
Description: In this work we address two problems in computational chemistry relevant to biomolecular modeling. In the first project, we consider the conformer space of melatonin as a a representative example of “real-life” flexible biomolecules. Geometries for all 52 unique conformers are optimized using spin-component scaled MP2, and then relative energies are obtained at the CCSD (T) level near the complete basis set limit. These are then used to validate a variety of DFT methods with and without empirical dispersion corrections, as well as some lower-level ab initio methods. Basis set convergence is found to be relatively slow due to internal C-H…O and C-H…N contacts. Absent dispersion corrections, many DFT functionals will transpose the two lowest conformers. Dispersion corrections resolve the problem for most functionals. Double hybrids yield particularly good performance, as does MP2.5. In the second project, we propose a simple DFT-based diagnostic for nondynamical correlation effects. Aλ= (1-TAE [ΧλC]/TAE[XC])/λ where TAE is the total atomization energy, XC the “pure” DFT exchange-correlation functional, and ΧλC the corresponding hybrid with 100λ% HF-type exchange. The diagnostic is a good predictor for sensitivity of energetics to the level of theory, unlike most of the wavefunction-based diagnostics. For GGA functionals, Aλ values approaching unity ...
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Anchor Nodes Placement for Effective Passive Localization

Anchor Nodes Placement for Effective Passive Localization

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Date: August 2010
Creator: Pasupathy, Karthikeyan
Description: Wireless sensor networks are composed of sensor nodes, which can monitor an environment and observe events of interest. These networks are applied in various fields including but not limited to environmental, industrial and habitat monitoring. In many applications, the exact location of the sensor nodes is unknown after deployment. Localization is a process used to find sensor node's positional coordinates, which is vital information. The localization is generally assisted by anchor nodes that are also sensor nodes but with known locations. Anchor nodes generally are expensive and need to be optimally placed for effective localization. Passive localization is one of the localization techniques where the sensor nodes silently listen to the global events like thunder sounds, seismic waves, lighting, etc. According to previous studies, the ideal location to place anchor nodes was on the perimeter of the sensor network. This may not be the case in passive localization, since the function of anchor nodes here is different than the anchor nodes used in other localization systems. I do extensive studies on positioning anchor nodes for effective localization. Several simulations are run in dense and sparse networks for proper positioning of anchor nodes. I show that, for effective passive localization, the ...
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Challenge the Silence

Challenge the Silence

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Date: August 2012
Creator: Peterson, Erica
Description: This collection of personal essays about incest, abuse, and depression explores the lasting effects of an invisible childhood. The essays follow the protagonist from the age of five to her early twenties. Her brother, at a young age, becomes sexually abusive of her and her sisters, and her parents fail to protect their daughters. The family is divided as the older girls strive to defend their little sisters, while their parents attempt to excuse their son. When her brother is finally sent away, the protagonist is left to salvage what remains of her relationships with her parents.
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A Chorus of Trees

A Chorus of Trees

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Date: August 2010
Creator: Lyons, Renée Kathleen
Description: This two-part thesis includes a critical preface and a collection of my poems. Using three poems-Louise Glück's "Lullaby," Bob Hicok's "Poem for My Mother's Hysterectomy," and Nick Flynn's "Memento Mori"-the critical preface examines how, in poetry, the transformation of a body negotiates trauma and triggers a conceptual shift, the creation and revision of identity, and the release of the duende's inspirational force. The collection of poetry that follows seeks to transfigure the body as a way to explore the nuanced traumas of human experience.
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El Cine De Terror Español Como Espejo De La Cultura Española

El Cine De Terror Español Como Espejo De La Cultura Española

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Date: May 2014
Creator: Donahue, Tyler
Description: This study traces the history and culture of Spain as seen through the lens of the nation´s production of horror cinema. Starting from the boom of Spanish horror film in the early 1960s, the thesis compares and contrasts the political and social aspects of Spanish society throughout three distinct eras of the 20th century: 1962 – 1975 (the boom of Spanish horror film through the Franco dictatorship), 1975 – 1999 (the transition to democracy through the end of the 20th century) and 2000 – present (the 21st century). Movies as diverse as Gritos en la noche (1962, Jesús Franco), ¿Quién puede matar a un niño? (1976, Narciso Ibáñez Serrador) and Angustia (1987, Bigas Luna) are framed by culturally-related anectodes as well as correlations to their respective social environments. Special attention has been paid to the production and release of each film, especially in regards to censorship during the Franco dictatorship. The results show that Spanish horror cinema has acted as a true mirror to culture, society and politics in its native country throughout the 20th century and that this trend will likely extend in to the future.
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A Comprehensive Modeling Framework for Airborne Mobility

A Comprehensive Modeling Framework for Airborne Mobility

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Date: December 2013
Creator: Xie, Junfei
Description: Mobility models serve as the foundation for evaluating and designing airborne networks. Due to the significant impact of mobility models on the network performance, mobility models for airborne networks (ANs) must realistically capture the attributes of ANs. In this paper, I develop a comprehensive modeling framework for ANs. The work I have done is concluded as the following three parts. First, I perform a comprehensive and comparative analysis of AN mobility models and evaluate the models based on several metrics: 1) networking performance, 2) ability to capture the mobility attributes of ANs, 3) randomness levels and 4) associated applications. Second, I develop two 3D mobility models and realistic boundary models. The mobility models follow physical laws behind aircraft maneuvering and therefore capture the characteristics of aircraft trajectories. Third, I suggest an estimation procedure to extract parameters in one of the models that I developed from real flight test data. The good match between the estimated trajectories and real flight trajectories also validate the suitability of the model. The mobility models and the estimation procedure lead to the creation of “realistic” simulation and evaluation environment for airborne networks.
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Cosmology, Extraterrestrial Life, and the Development and Character of Western European Thought in the Seventeenth and Eighteenth Centuries

Cosmology, Extraterrestrial Life, and the Development and Character of Western European Thought in the Seventeenth and Eighteenth Centuries

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Date: August 2011
Creator: Simpson, Emily
Description: Cosmology, as an all-encompassing theoretical construction of universal reality, serves as one of the best indicators for a variety of philosophical, scientific, and cultural values. Within any cosmological system, the question of extraterrestrial life is an important element. Mere existence or nonexistence, however, only exposes a small portion of the ideological significance behind the contemplation of life outside of earth. The manners by which both believers and disbelievers justify their opinions and the ways they characterize other worlds and their inhabitants show much more about the particular ideas behind such decisions and the general climate of thought surrounding those who consider the topic. By exploring both physical and abstract structures of the universe, and specifically concepts on the plurality of worlds and extraterrestrial life, Western European thought in the seventeenth and eighteenth centuries reveals not an era of pure advancement and modernization, but as a time of both tradition and change.
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Cuff-less Blood Pressure Measurement Using a Smart Phone

Cuff-less Blood Pressure Measurement Using a Smart Phone

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Date: May 2012
Creator: Jonnada, Srikanth
Description: Blood pressure is vital sign information that physicians often need as preliminary data for immediate intervention during emergency situations or for regular monitoring of people with cardiovascular diseases. Despite the availability of portable blood pressure meters in the market, they are not regularly carried by people, creating a need for an ultra-portable measurement platform or device that can be easily carried and used at all times. One such device is the smartphone which, according to comScore survey is used by 26.2% of the US adult population. the mass production of these phones with built-in sensors and high computation power has created numerous possibilities for application development in different domains including biomedical. Motivated by this capability and their extensive usage, this thesis focuses on developing a blood pressure measurement platform on smartphones. Specifically, I developed a blood pressure measurement system on a smart phone using the built-in camera and a customized external microphone. the system consists of first obtaining heart beats using the microphone and finger pulse with the camera, and finally calculating the blood pressure using the recorded data. I developed techniques for finding the best location for obtaining the data, making the system usable by all categories of people. ...
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Daily-collected Sleep Diaries Compared to Weekly-collected Sleep Diaries Via Actigraph Concordance

Daily-collected Sleep Diaries Compared to Weekly-collected Sleep Diaries Via Actigraph Concordance

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Date: May 2014
Creator: Francetich, Jade M.
Description: Both sleep diaries and actigraphy have been recommended to assess sleep in research and clinical settings. Investigators have traditionally used sleep diaries that were completed daily by participants and collected weekly but have recently begun using sleep diaries that are both completed and collected daily. No research had previously assessed the agreement between daily-collected sleep diaries and actigraph data over one week. Undergraduate students were randomly assigned to use daily- or weekly-collected sleep diaries. Sleep parameters obtained from these measures were compared to each other via concordance with concurrent actigraph data. It was hypothesized that daily-collected sleep diaries would have greater concordance with actigraphy than weekly-collected sleep diaries. Results indicated that daily-collected sleep diaries provided more reliable data than weekly-collected sleep diaries, but the differences were not statistically significant. Additional aims examined self-reported sleep diary adherence, the participation day number, and day of the week. There were trends for the Daily group to have better adherence. Overall concordance did not change based on the day number or day of the week. Both sleep diaries yield comparable sleep parameter data, suggesting that clinicians and researchers can use either method to estimate sleep parameters.
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Data Compression Using a Multi-residue System (Mrs)

Data Compression Using a Multi-residue System (Mrs)

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Date: August 2012
Creator: Melaedavattil Jaganathan, Jyothy
Description: This work presents a novel technique for data compression based on multi-residue number systems. The basic theorem is that an under-determined system of congruences could be solved to accomplish data compression for a signal satisfying continuity of its information content and bounded in peak-to -peak amplitude by the product of relatively prime moduli,. This thesis investigates this property and presents quantitative results along with MATLAB codes. Chapter 1 is introductory in nature and Chapter 2 deals in more detail with the basic theorem. Chapter 3 explicitly mentions the assumptions made and chapter 4 shows alternative solutions to the Chinese remainder theorem. Chapter 5 explains the experiments in detail whose results are mentioned in chapter 6. Chapter 7 concludes with a summary and suggestions for future work.
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