Physical Sciences and Mathematics Commons^™

Stability Of Nonlinear Filters And Branching Particle Approximations To The Filtering Problems, Zhiqiang Li

Doctoral Dissertations

Various particle filters have been proposed and their convergence to the optimal filter are obtained for finite time intervals. However, uniform convergence results have been established only for discrete time filters. We prove the uniform convergence of a branching particle filter for continuous time setup when the optimal filter itself is exponentially stable.

The short interest rate process is modeled by an asymptotically stationary diffusion process. With the counting process observations, a filtering problem is formulated and its exponential stability is derived. Base on the stability result, the uniform convergence of a branching particle filter is proved.

Hyperbolic Structures From Link Diagrams, Anastasiia Tsvietkova

Doctoral Dissertations

As a result of Thurston's Hyperbolization Theorem, many 3-manifolds have a hyperbolic metric or can be decomposed into pieces with hyperbolic metric (W. Thurston, 1978). In particular, Thurston demonstrated that every link in a 3-sphere is a torus link, a satellite link or a hyperbolic link and these three categories are mutually exclusive. It also follows from work of Menasco that an alternating link represented by a prime diagram is either hyperbolic or a (2,n)-torus link.

A new method for computing the hyperbolic structure of the complement of a hyperbolic link, based on ideal polygons bounding the regions of a …

Failure Prediction For High-Performance Computing Systems, Narate Taerat

Doctoral Dissertations

The failure rate in high-performance computing (HPC) systems continues to escalate as the number of components in these systems increases. This affects the scalability and the performance of parallel applications in large-scale HPC systems. Fault tolerance (FT) mechanisms help mitigating the impact of failures on parallel applications. However, utilizing such mechanisms requires additional overhead. Besides, the overuse of FT mechanisms results in unnecessarily large overhead in the parallel applications. Knowing when and where failures will occur can greatly reduce the excessive overhead. As such, failure prediction is critical in order to effectively utilize FT mechanisms. In addition, it also helps …

A Failure Index For High Performance Computing Applications, Clayton F. Chandler

Doctoral Dissertations

This dissertation introduces a new metric in the area of High Performance Computing (HPC) application reliability and performance modeling. Derived via the time-dependent implementation of an existing inequality measure, the Failure index (FI) generates a coefficient representing the level of volatility for the failures incurred by an application running on a given HPC system in a given time interval. This coefficient presents a normalized cross-system representation of the failure volatility of applications running on failure-rich HPC platforms. Further, the origin and ramifications of application failures are investigated, from which certain mathematical conclusions yield greater insight into the behavior of these …

Numerical Simulation Of Nanopulse Penetration Of Biological Matter Using The Adi-Fdtd Method, Fei Zhu

Doctoral Dissertations

Nanopulses are ultra-wide-band (UWB) electromagnetic pulses with pulse duration of only a few nanoseconds and electric field amplitudes greater than 105 V/m. They have been widely used in the development of new technologies in the field of medicine. Therefore, the study of the nanopulse bioeffects is important to ensure the appropriate application with nanopulses in biomedical and biotechnological settings. The conventional finite-difference time-domain (FDTD) method for solving Maxwell's equations has been proven to be an effective method to solve the problems related to electromagnetism. However, its application is restricted by the Courant, Friedrichs, and Lewy (CFL) stability condition that confines …

The Search For An Optimal Means Of Determining The Minmax Control Parameter Using Sensitivity Analysis, John Teye Brown

Doctoral Dissertations

The use of computational methods for design and simulation of control systems allows for a cost-effective trial and error approach. In this work, we are concerned with the robust, real-time control of physical systems whose state space is infinite-dimensional. Such systems are known as Distributed Parameter Systems (DPS). A body whose state is heterogeneous is a distributed parameter. In particular, this work focuses on DPS systems that are governed by linear Partial Differential Equations, such as the heat equation. We specifically focus on the MinMax controller, which is regarded as being a very robust controller. The mathematical formulation of the …

Mathematical Modeling Of Pipeline Features For Robotic Inspection, Yang Gao

Doctoral Dissertations

Underground pipeline systems play an indispensable role in transporting liquids in both developed and developing countries. The associated social and economic cost to repair a pipe upon abrupt failure is often unacceptable. Regular inspection is a preventative action that aims to monitor pipe conditions, catch abnormalities and reduce the chance of undesirable surprises. Robots with CCTV video cameras have been used for decades to inspect pipelines, yielding only qualitative information. It is becoming necessary and preferable for municipalities, project managers and engineers to also quantify the 3-D geometry of underground pipe networks. Existing robots equipped specialized hardware and software algorithms …

Near-Optimal Scheduling And Decision-Making Models For Reactive And Proactive Fault Tolerance Mechanisms, Nichamon Naksinehaboon

Doctoral Dissertations

As High Performance Computing (HPC) systems increase in size to fulfill computational power demand, the chance of failure occurrences dramatically increases, resulting in potentially large amounts of lost computing time. Fault Tolerance (FT) mechanisms aim to mitigate the impact of failure occurrences to the running applications. However, the overhead of FT mechanisms increases proportionally to the HPC systems' size. Therefore, challenges arise in handling the expensive overhead of FT mechanisms while minimizing the large amount of lost computing time due to failure occurrences.

In this dissertation, a near-optimal scheduling model is built to determine when to invoke a hybrid checkpoint …

Economics And Finance On Time Scales, Julius Severin Heim

Doctoral Dissertations

"This thesis consists of 6 papers that investigate models in economics and finance based on so-called dynamic equations on time scales. The first paper covers multiplier-accelerator models that can be described by linear second-order dynamic equations. The possibility of taxes as well as the possibility of foreign trade is taken into consideration. The second paper discusses cobweb models, which describe cyclical supply and demand in markets, where the supply is determined before the observation of the price. Cobweb models that can be formulated with first-order linear, second-order linear, and nonlinear dynamic equations are being considered. The third and fourth papers …

Part I: Quantitative Determination Of Total Corrosive Sulfur In Mineral Insulating Oils And Technical Liquids; Part Ii: Development And Validation Of A Broad Spectrum Microbial Disinfectant, Kyle Rodney Anderson

Doctoral Dissertations

"Part one of this dissertation deals with the development and validation of a test method for determination of total corrosive sulfur in mineral insulating oils other technical oils. The method involved reaction of corrosive sulfur compounds in oils with finely divided copper at temperatures ≥ 110 °C. The reaction yielded cuprous sulfide (Cu₂S), Cu₂S was then oxidized to cupric sulfate (CuSO₄), which was determined as sulfate with ion chromatography. The method offers a quantitative assessment of corrosive sulfur compounds in oils and eliminates ambiguities associated with the international standard methods for corrosive sulfur in mineral insulating oils and other technical …

Periodic Q-Difference Equations, Rotchana Chieochan

Doctoral Dissertations

"The concept of periodic functions defined on the real numbers or on the integers is a classical topic and has been studied intensively, yielding numerous applications in every kind of science. It is of importance that the real numbers and the integers are closed with respect to addition. However, for a number q > 1, the so-called q-time scale, i.e., the set of nonnegative integer powers of q, is not closed with respect to addition, and therefore it was not possible to define periodic functions on the q-time scale in an obvious way. In this thesis, this important open problem has …

Complex Oxides As Novel Transparent Conductors, Altynbek Murat

Doctoral Dissertations

"Ab-initio density functional approach is employed to investigate the structural, optical, and electronic properties of twelve undoped (non)stoichiometric multicomponent oxides with layered structure RAMO₄ [R³⁺ =In or Sc, A³⁺ =Al or Ga, and M²⁺ - Ca, Cd, Mg, or Zn], as candidates for novel transparent conducting oxides. The compositional complexity of RAMO₄ leads to a wide range of band gaps varying from 2.45eV for InGaCdO₄ to 6.29 eV for ScAlMgO₄. We find that despite the different band gaps in the constituent binary oxides, namely, 2-4 eV in CdO, In₂O₃, or AnO; 5-6 eV for Ga₂O₃ or Sc₂O₃; and 7-9 eV …

Complex Scaling Behavior In Animal Foraging Patterns, Prabhavi Kaushalya Premachandra

Doctoral Dissertations

This dissertation attempts to answer questions from two different areas of biology, ecology and neuroscience, using physics-based techniques. In Section 2, suitability of three competing random walk models is tested to describe the emergent movement patterns of two species of primates. The truncated power law (power law with exponential cut off) is the most suitable random walk model that characterizes the emergent movement patterns of these primates. In Section 3, an agent-based model is used to simulate search behavior in different environments (landscapes) to investigate the impact of the resource landscape on the optimal foraging movement patterns of deterministic foragers. …

Chelating Compounds As Potential Flash Rust Inhibitors And Melamine & Aziridine Cure Of Acrylic Colloidal Unimolecular Polymers (Cups), Jigar K. Mistry

Doctoral Dissertations

Waterborne coatings on ferrous substrates usually show flash rusting which decreases the adhesion of the coating and the corrosion products can form a stain. Chelating compounds were investigated as potential flash rust inhibitors. Compounds being evaluated include amine alcohols, diamines and sulfur containing amines. A new corrosion inhibitor 2,5-bis(thioaceticacid)-1,3,4-thiadiazole (H2ADTZ) was synthesized and its performance characteristics were evaluated. It was noted that the observed structure of 1,3,4-thiadiazolidine-2,5-dithione (also known as 2,5-dimercapto-1,3,4-thiadiazole (DMTD or DMcT)) has been previously reported in three different tautomeric forms including -dithiol and -dithione. The relative stability of each form as well as the synthesis and characterization …

Nano-Particles Induced Oxidative Stress In Immortalized Human Brain Endothelial Cells, Xinsheng Zhang

Doctoral Dissertations

"Nanoparticles are engineered structure with at least one dimension of 100 nanometers or less. These materials are increasingly being used for commercial purposes such as catalyst, semiconductor, cosmetics, microelectronic, and drug carrier. However, the toxicological impact of these materials has not yet been studied in detail, thereby limiting their use. In our present study, we use human brain endothelial cell line as a blood-brain barrier (BBB) model to investigate if two kinds of nanoparticles [ 1). Diesel exhaust particles (DEPs) and 2). single wall carbon nanotube (CNT) ] induced oxidative stress in cell model. Our studies showed that DEPs or …

Mantle Flow And Lithosphere-Asthenosphere Coupling Beneath The Southwestern Edge Of The North American Craton: Constraints From Shear-Wave Splitting Measurements, Hesham A. Refayee

Doctoral Dissertations

"High-quality broadband seismic data recorded by the USArray and other stations in the southwestern United States provide a unique opportunity to test different models of anisotropy-forming mechanisms in the vicinity of a cratonic edge. Systematic spatial variations of anisotropic characteristics are revealed by 3027 pairs of splitting parameters measured at 547 broadband seismic stations. The western and southern edges of the North American craton show edge-parallel fast directions with larger-than-normal splitting times, and the continental interior is characterized by smaller splitting times spatially consistent fast directions that are mostly parallel to the absolute plate motion direction of North America. Except …

Plate Kinematics Of The Afro-Arabian Rift System With An Emphasis On The Afar Depression, Helen Carrie Bottenberg

Doctoral Dissertations

This work utilizes the Four-Dimensional Plates (4DPlates) software, and Differential Interferometric Synthetic Aperture Radar (DInSAR) to examine plate-scale, regional-scale and local-scale kinematics of the Afro-Arabian Rift System with emphasis on the Afar Depression in Ethiopia. First, the 4DPlates is used to restore the Red Sea, the Gulf of Aden, the Afar Depression and the Main Ethiopian Rift to development of a new model that adopts two poles of rotation for Arabia. Second, the 4DPlates is used to model regional-scale and local-scale kinematics within the Afar Depression. Most plate reconstruction models of the Afro-Arabian Rift System relies on considering the Afar …

The Characterization Of Volatiles Associated With Young Stellar Objects, Kari Anne Wojtkowski

Doctoral Dissertations

In the first portion of this work, we searched for differences in volatiles within a single star forming region, Rho Ophiuchi. We determined the amount, temperature, and composition of two ice features, the bending modes of CO₂ and H₂O at 15 µm and 6 µm, respectively, toward 28 Young Stellar Objects (YSOs). We found that more than 50% of the YSOs studied contained a portion of crystalline CO₂ ice. We also found that some sources with Flat or borderline Class II Spectral Energy Distributions (SEDs) have a larger abundance of CO₂ ice with respect to H₂O ice. In addition to …

Evolutionary Computing Driven Search Based Software Testing And Correction, Joshua Lee Wilkerson

Doctoral Dissertations

"For a given program, testing, locating the errors identified, and correcting those errors is a critical, yet expensive process. The field of Search Based Software Engineering (SBSE) addresses these phases by formulating them as search problems. This dissertation addresses these challenging problems through the use of two complimentary evolutionary computing based systems. The first one is the Fitness Guided Fault Localization (FGFL) system, which novelly uses a specification based fitness function to perform fault localization. The second is the Coevolutionary Automated Software Correction (CASC) system, which employs a variety of evolutionary computing techniques to perform testing, correction, and verification of …

Theoretical Studies Of Few-Body Problems, Uttam Chowdhury

Doctoral Dissertations

"Heavy ion collisions with atomic and molecular targets produce many outcomes. The Schrödinger equation is not analytically soluble for more than two mutually interacting particles. As a result, theory must resort to using approximations, the validity of which is determined by comparison with experiment. This work is focused on finding better approximations to describe ionization and capture processes in proton collisions.

Proton-impact ionization of molecular hydrogen is treated as a 3-body problem. Usually the target is treated as an atomic target and the results are multiplied by an ad hoc factor to account for the molecular structure. Measured cross sections …

A Monte Carlo Study Of The Scaling Of Nucleation Rates In A Lennard-Jones System, Mark Allan Thomason

Doctoral Dissertations

Temperature scaling of the homogenous vapor-to-liquid nucleation rate, J, is examined in a model Lennard-Jones (LJ) system. The model uses the Bennett Metropolis Monte Carlo technique to determine small cluster growth/decay rate constant ratios ß_n-1|α_n at four temperatures (T = 40, 50, 60, and 83.6K) below the argon Lennard-Jones critical temperature, T_c. The ß_n-1|α_n for clusters ranging in size from n = 2 to n = 192 LJ particles are applied to a kinetic steady-state nucleation rate formalism and nucleation rates are determined at the same four temperatures. When these rates are …

Therapeutic Effects Of N-Acetylcysteine Amide In The Treatment Of Eye Disorders, Joshua W. Carey

Doctoral Dissertations

"The loss of vision from age-related eye diseases now affects over 30 million people in the United States and is expected to reach twice that number within the next couple of decades. Among these disorders, age-related macular degeneration and cataract formation represent the largest percentage of these cases. Therapeutic options available for treating age-related macular degeneration are limited and there is no noninvasive form of treatment for cataracts current available. Several studies have indicated that oxidative stress plays an important role in the pathology of these age-related eye disorders. If oxidative stress is responsible for the initiation and progression of …

Handel's Maser-Solution Theory Of Ball Lightning: The Creation Of Stable Three-Dimensional Cavitons By An Atmospheric Maser With An Open Resonator, Glenn Andrew Carlson

Doctoral Dissertations

"This dissertation develops details of Handel's Maser-Soliton Theory of ball lightning. The atmosphere between a thundercloud and the Earth's surface is modeled as an idealized stable open resonator with water vapor as the active medium and the thundercloud and Earth's surface as reflecting surfaces. The stable resonator generates a maser beam that narrows to the beam waist at the Earth's surface, which is assumed to be planar. Two candidate rotational transitions are identified within the v₁v₂v₃ = 010 vibrational band of water having wavelengths of 13.9 cm and 1.12 cm, and relevant spectroscopic parameters are retrieved from the HITRAN 2008 …

Investigation Of Biomarkers For Noninvasive Early Diagnosis Of Cancer, Sanjeewa Bandara Gamagedara

Doctoral Dissertations

"Cancer is the second leading cause of death worldwide, and deaths from cancer worldwide are projected to continue rising, with an estimated 12 million deaths in 2030. Cancer occurs when cells in a part of the body begin to grow out of control. It develops very rapidly, and early diagnosis offers a greater chance of successful treatment and a higher survival rate. Biomarkers are good potential tools for early diagnosis. The main hypothesis of this study is that the levels of certain metabolites present in human urine can indicate the current or future behavior of cancer. Therefore, these studies focused …

Organic And Composite Aerogels Through Ring Opening Metathesis Polymerization (Romp), Dhairyashil Mohite

Doctoral Dissertations

"Aerogels are open-cell nanoporous materials, unique in terms of low density, low thermal conductivity, low dielectric constants and high acoustic attenuation. Those exceptional properties stem from their complex hierarchical solid framework (agglomerates of porous, fractal secondary nanoparticles), but they also come at a cost: low mechanical strength. This issue has been resolved by crosslinking silica aerogels with organic polymers. The crosslinking polymer has been assumed to form a conformal coating on the surface of the skeletal framework by covalent bridging elementary building blocks. However, "assuming" is not enough: for correlating nanostructure with bulk material properties, it is important to know …

Quantitative Analysis Of Co-Enzyme A In A Plant Tissues And Cancer Biomarkers In Urine Samples By Using Capillary Electrophoresis And Liquid Chromatography-Mass Spectrometry, Yongqing Jiang

Doctoral Dissertations

"Despite continuous effort and progress in cancer detection and therapy, cancer remains one of our greatest health concerns because of its low survival rate and rapid incidence increase. One reason for this is the late detection and therefore pre-cancer diagnosis is crucial. In pre-cancer studies, cancer biomarkers become significant because of the useful information it contains such as possible cancer type and stage. Separation and detection technique plays an important role in cancer biomarker identification.

Coenzyme A (CoA) facilitates more than 100 chemical reactions in cells. Because of its low abundance accumulated in cells, it is critical to develop a …

X-Ray Crystallography For The Study Of Nickel And Iron Salicylaldimines, Carla Schmiesing Eribal

Doctoral Dissertations

"X-ray diffraction of single crystals has developed dramatically over the last century by combining fundamental theories of light, diffraction, and statistics to generate the complete, geometric structure of molecules. The quality of the resulting X -ray structure data are reported in R₁ < 5%, wR2 < 12% and a goodness of fit value of one. This technique was applied specifically to the evaluation of the spin crossover (SCO) compound [Fe(salpm)₂]BF₄ʺ0.5EtOH and how the molecule's geometry changed during a two-step thermal LS-HS conversion. The crystal structure was measured at 100,175,225, and 296 K to yield final R₁ values of 0.047, 0.054, 0.051, and 0.058, respectively. The coordination bond lengths show the spin transitions occur between 100-175K at one crystallographically unique Fe and between 175-225K at the other Fe site. No strong long range interactions are found, suggesting a gradual spin transition. Reaction ofNi(Nalkyl-sal)₂ complexes with Ni(N0₃)₂ form either nickel dimeric, [Ni₃(Rsal)(N0₃)(MeOH)]₂ or trinuclear complexes, Ni₃(Rsal)₄(N0₃)₂. The binuclear complexes, with orthogonal bridging ligands, show overall ferromagnetic interactions. The crystal structures for Ni₃(Rsal)₄(N0₃)₂ from methyl to benzyl were solved and indicate no steric restriction on formation for the series. The trinuclear compounds form an isosceles triangle of metal atoms with the isopropyl analog showing an overall antiferromagnetic interaction with J=+11.386 and J23=-13.891. Lastly, xanthene spirolactam derivatives were structurally analyzed to determine binding modes for their selective and sensitive (µM) detection of metals Cr³⁺, Fe³⁺, Ni²⁺, Co²⁺ and the nerve gas mimic, dichlorophosphate"--Abstract, page iii.

Characterization Of Wave Transport In Non-Conservative Media With Random And Correlated Disorder, Benjamin Henry Payne

Doctoral Dissertations

"Passive quasi-one-dimensional random media exhibit one of the three regimes of transport - ballistic, diffusive, or Anderson localization - depending on system size. The ballistic and diffusion approximations assumes particle transport, whereas Anderson Localization occurs when wave self-interference effects are dominant. When the system contains absorption or gain, then how the regimes can be characterized becomes unclear. By investigating theoretically and numerically the ratio of transmission to energy in a random medium in one dimension, we show this parameter can be used to characterize localization in random media with gain. Non-conservative media implies a second dimension for the transport parameter …

Synthesis And Applications Of Imidazolium-Based Ionic Liquids And Their Polymer Derivatives, Woon Su Oh

Doctoral Dissertations

"Imidazolium-based ionic liquids have been increasingly used as green solvents to replace the volatile and relatively toxic organic solvents, in homogeneous and heterogeneous catalysis, materials science, nano materials, lithium ion batteries, and separation technology. Section 1 describes the modulating effect of the imidazolium based room temperature ionic liquids (RTILs) on the critical micelle concentrations (CMC) of surfactants. CMC of sodium dodecyl sulfate (SDS), an anionic surfactant, has been investigated in aqueous solutions of a variety of room temperature ionic liquids (RTILs). CMC values decrease with increasing alkyl chain-length and with fluorinated side chains on the imidazole moiety. In section 2, …

Electrodeposition And Electrochemical Reduction Of Epitaxial Metal Oxide Thin Films And Superlattices, Zhen He

Doctoral Dissertations

"The focus of this dissertation is the electrodeposition and electrochemical reduction of epitaxial metal oxide thin films and superlattices. The electrochemical reduction of metal oxides to metals has been studied for decades as an alternative to pyrometallurgical processes for the metallurgy industry. However, the previous work was conducted on bulk polycrystalline metal oxides. Paper I in this dissertation shows that epitaxial face-centered cubic magnetite (Fe₃O₄) thin films can be electrochemically reduced to epitaxial body-centered cubic iron (Fe) thin films in aqueous solution on single-crystalline Au substrates at room temperature. This technique opens new possibilities to produce special epitaxial metal/metal oxide …