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2007

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Articles 2551 - 2580 of 6758

Full-Text Articles in Physical Sciences and Mathematics

Preprocessing Of Sar Interferometric Data Using Anisotropic Diffusion Filter, Kenneth Sartor, Josef Vaughn De Allen, Emile Ganthier, Gnana Bhaskar Tenali May 2007

Preprocessing Of Sar Interferometric Data Using Anisotropic Diffusion Filter, Kenneth Sartor, Josef Vaughn De Allen, Emile Ganthier, Gnana Bhaskar Tenali

Mathematics and System Engineering Faculty Publications

The most commonly used smoothing algorithms for complex data processing are blurring functions (i.e., Hanning, Taylor weighting, Gaussian, etc.). Unfortunately, the filters so designed blur the edges in a Synthetic Aperture Radar (SAR) scene, reduce the accuracy of features, and blur the fringe lines in an interferogram. For the Digital Surface Map (DSM) extraction, the blurring of these fringe lines causes inaccuracies in the height of the unwrapped terrain surface. Our goal here is to perform spatially non-uniform smoothing to overcome the above mentioned disadvantages. This is achieved by using a Complex Anisotropic Non-Linear Diffuser (CANDI) filter that is a …

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Magnetic Impurities In Magic-Number Clusters, Ralph Skomski, David J. Sellmyer May 2007

Magnetic Impurities In Magic-Number Clusters, Ralph Skomski, David J. Sellmyer

Ralph Skomski Publications

It is investigated how magnetic impurities modify the behavior of metallic clusters. Two complementary models are used, an s-d exchange model with a stable magnetic moment and a Hubbard-type Kondo model. The s-d and s-f interactions are modeled by a pointlike potential, as in the Ruderman-Kittel-Kasuya-Yosida approximation, but the perturbed levels are obtained by diagonalizing the interaction matrix rather than using perturbation theory. The spin polarization of the conduction electrons due to the magnetic impurities leads to a reduction of the highest occupied molecular orbital–lowest unoccupied molecular orbital splitting. A particularly interesting case is …

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Towards Early State Disease Detection In Microdevices: Fabrication And Testing Of Micro Total Analysis Systems For Bioanalytical Applications, Tao Pan May 2007

Towards Early State Disease Detection In Microdevices: Fabrication And Testing Of Micro Total Analysis Systems For Bioanalytical Applications, Tao Pan

Theses and Dissertations

The past few years have seen a rapid expansion in interest in the characterization of the entire complement of proteins, or proteome. Micro total analysis systems (μTAS) are an emerging promising method, offering rapid, sensitive and low sample consumption separations. I have demonstrated microchip capillary electrophoresis (CE) devices made of CaF2. New methods have been developed for micromachining enclosed capillaries in CaF2. CE analysis of fluorescently labeled amino acids was used to illustrate bioanalytical applications of these microdevices. Initial on-chip infrared spectroscopy results for qualitative analyte identification were achieved in microfluidic CaF2 channels. I have also shown the evaluation of …

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Energy Deposition Study Of Low-Energy Cosmic Radiation At Sea Level, Pushpa Indumathie Wijesinghe May 2007

Energy Deposition Study Of Low-Energy Cosmic Radiation At Sea Level, Pushpa Indumathie Wijesinghe

Physics and Astronomy Dissertations

In this dissertation work, a computer simulation model based on the Geant4 simulation package has been designed and developed to study the energy deposition and track structures of cosmic muons and their secondary electrons in tissue-like materials. The particle interactions in a cubic water volume were first simulated. To analyze the energy deposition and tracks in small structures, with the intention of studying the energy localization in nanometric structures such as DNA, the chamber was sliced in three dimentions. Validation studies have been performed by comparing the results with experimental, theoretical, and other simulation results to test the accuracy of …

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Origin And Tectonic Evolution Of Gondwana Sequence Units Accreted To The Banda Arc: A Structural Transect Through Central East Timor, Elizabeth Anick Zobell May 2007

Origin And Tectonic Evolution Of Gondwana Sequence Units Accreted To The Banda Arc: A Structural Transect Through Central East Timor, Elizabeth Anick Zobell

Theses and Dissertations

Petrographic and age analysis of sandstones, detailed structural analysis and gravity modeling were conducted to investigate the origin of the Gondwana Sequence in the Timor Region, and to better constrain the tectonic evolution of the active Banda Arc. Our field studies and U/Pb zircon age analysis helped assign most units to either Asian or Australian affinity. Detrital zircon from uplifted Banda forearc units (Asian affinity) have U/Pb ages as young as 80 Ma (Standley and Harris, in press). In contrast, analysis of detrital zircon from Gondwana Sequence sandstones accreted to the Banda Arc from Savu to East Timor are no …

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Two Or Four: A Hint From Scalar Mesons In Radiative Phi Decays?, Joseph Schechter, Deirdre Black, Masayasu Harada May 2007

Two Or Four: A Hint From Scalar Mesons In Radiative Phi Decays?, Joseph Schechter, Deirdre Black, Masayasu Harada

Physics - All Scholarship

In this write-up, we summarize our recent analysis of radiative decays involving light scalar mesons. Our analysis using the vector meson dominance model at tree level indicates that it may be difficult to distinguish qq\bar{q}\bar{q} picture and q\bar{q} picture for the light scalar nonet. Our result on the process of \phi \to \pi^0 \eta \gamma shows that the derivative-type f_0 K\bar{K} interaction reproduces experimental data below 950 GeV well, but gives a poor fit above 950 GeV, i.e., in the energy region around the mass of a_0(980), but that the discrepancy can be compensated by the effect of the K …

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Alliance Partitions In Graphs., Jason Lachniet May 2007

Alliance Partitions In Graphs., Jason Lachniet

Electronic Theses and Dissertations

For a graph G=(V,E), a nonempty subset S contained in V is called a defensive alliance if for each v in S, there are at least as many vertices from the closed neighborhood of v in S as in V-S. If there are strictly more vertices from the closed neighborhood of v in S as in V-S, then S is a strong defensive alliance. A (strong) defensive alliance is called global if it is also a dominating set of G. The alliance partition number (respectively, strong …

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Epidemic Of Lung Cancer Or Artifact Of Classification In The State Of Kentucky?, Beatrice Simo May 2007

Epidemic Of Lung Cancer Or Artifact Of Classification In The State Of Kentucky?, Beatrice Simo

Electronic Theses and Dissertations

Lung cancer remains the leading cause of cancer deaths in the United States despite public health campaigns aimed at reducing its rate of mortality. Kentucky is the state with the highest lung cancer incidence and mortality. This study aims to assess the impact of misclassification of cause of death from Lung Cancer in Kentucky for the period 1979 to 2002. We will examine the potential competing classification of death for two other smoking-related diseases, Chronic Obstructive Pulmonary Disease (COPD) and Emphysema. Age-adjusted mortality rates for these diseases for white males were obtained from the National Center for Health Statistics. There …

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Factors That Affect The Global Positioning System And Global Navigation Satellite System In An Urban And Forested Environment., Douglas Allen Ritchie May 2007

Factors That Affect The Global Positioning System And Global Navigation Satellite System In An Urban And Forested Environment., Douglas Allen Ritchie

Electronic Theses and Dissertations

The purpose of this study was to evaluate the accuracy in real time measurements acquired from GPS and GLONASS satellite observations using RTK techniques in an urban and forested environment. To determine this accuracy, 2 data sets of 3-dimensional coordinates were created and compared at 14 stations situated at East Tennessee State University. One data set included coordinates determined by conventional land survey methods; the second was solved by RTK GPS/GLONASS. Once the magnitude of any deviation in the coordinate positions was determined, the contributions to the accuracies from cycle slips, multipath, satellite availability, PDOP, and fixed or float solutions …

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Dendrochronological Analysis Of Oak (Quercus) Beams From The Coshocton (Darr) Log Barn, Coshocton County, Ohio May 2007

Dendrochronological Analysis Of Oak (Quercus) Beams From The Coshocton (Darr) Log Barn, Coshocton County, Ohio

Historic Structures

Dating historical structures in Coshocton County, Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Belding, Elyssa; Wiles, Greg.

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Dendrochronological Analysis Of Oak (Quercus) Tree Cores And Cross-Sections From The Larry Reed Log Barn, Noble County, Ohio May 2007

Dendrochronological Analysis Of Oak (Quercus) Tree Cores And Cross-Sections From The Larry Reed Log Barn, Noble County, Ohio

Historic Structures

Dating historical structures in Noble County, Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Belding, Elyssa; Wiles, Greg

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Sem Analysis Of Glue Behavior When Bonding Glass Structures With Complex Geometries, Yuri Sikorski, Robert Cunningham, Herman Orgeron, Chris Schenck, Ali Zand May 2007

Sem Analysis Of Glue Behavior When Bonding Glass Structures With Complex Geometries, Yuri Sikorski, Robert Cunningham, Herman Orgeron, Chris Schenck, Ali Zand

Chemistry & Biochemistry Presentations And Conference Materials

Bonding of glass has been studied for many years and is a mature technology today. However, the recent advances in bio-photonics and micro-fluidics, such as lab-on-a-chip devices, accentuate a need to provide reliable adhesion and sealing of components with extremely complex surface geometries. In many cases it is necessary to prevent the adhesives from leaking into microscopic channels, capillaries and holes. We present the Scanning Electron Microscopy study of adhesion of glass samples with complex surface features. Variety of adhesion conditions and procedures were tried and studied. The results demonstrate the possibility of controlled reliable adhesion and sealing without filling/obstructing …

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An Extension Of Ramsey's Theorem To Multipartite Graphs, Brian Michael Cook May 2007

An Extension Of Ramsey's Theorem To Multipartite Graphs, Brian Michael Cook

Mathematics Theses

Ramsey Theorem, in the most simple form, states that if we are given a positive integer l, there exists a minimal integer r(l), called the Ramsey number, such any partition of the edges of K_r(l) into two sets, i.e. a 2-coloring, yields a copy of K_l contained entirely in one of the partitioned sets, i.e. a monochromatic copy of Kl. We prove an extension of Ramsey's Theorem, in the more general form, by replacing complete graphs by multipartite graphs in both senses, as the partitioned set and as the desired monochromatic graph. More formally, given integers l and k, there …

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Empirical Likelihood Confidence Intervals For The Sensitivity Of A Continuous-Scale Diagnostic Test, Angela Elaine Davis May 2007

Empirical Likelihood Confidence Intervals For The Sensitivity Of A Continuous-Scale Diagnostic Test, Angela Elaine Davis

Mathematics Theses

Diagnostic testing is essential to distinguish non-diseased individuals from diseased individuals. More accurate tests lead to improved treatment and thus reduce medical mistakes. The sensitivity and specificity are two important measurements for the diagnostic accuracy of a diagnostic test. When the test results are continuous, it is of interest to construct a confidence interval for the sensitivity at a fixed level of specificity for the test. In this thesis, we propose three empirical likelihood intervals for the sensitivity. Simulation studies are conducted to compare the empirical likelihood based confidence intervals with the existing normal approximation based confidence interval. Our studies …

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Development Of Cosmic Ray Simulation Program -- Earth Cosmic Ray Shower (Ecrs), Sampath S. Hakmana Witharana May 2007

Development Of Cosmic Ray Simulation Program -- Earth Cosmic Ray Shower (Ecrs), Sampath S. Hakmana Witharana

Physics and Astronomy Dissertations

ECRS is a program for the detailed simulation of extensive air shower initiated by high energy cosmic ray particles. In this dissertation work, a Geant4 based ECRS simulation was designed and developed to study secondary cosmic ray particle showers in the full range of Earth's atmosphere. A proper atmospheric air density and geomagnetic field are implemented in order to correctly simulate the charged particles interactions in the Earth's atmosphere. The initial simulation was done for the Atlanta (33.460 N , 84.250 W) region. Four different types of primary proton energies (109, 1010, 1011 and 1012 eV) were considered to determine …

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Numerical Hydrodynamics Of Relativistic Extragalactic Jets, Eunwoo Choi May 2007

Numerical Hydrodynamics Of Relativistic Extragalactic Jets, Eunwoo Choi

Physics and Astronomy Dissertations

This dissertation describes a multidimensional relativistic hydrodynamic code which solves the special relativistic hydrodynamic equations as a hyperbolic system of conservation laws based on the total variation diminishing (TVD) scheme. Several standard tests and test simulations are presented to demonstrate the accuracy, robustness and flexibility of the code. Using this code we have studied three-dimensional hydrodynamic interactions of relativistic extragalactic jets with two-phase ambient media. The deflection angle of the jet is influenced more by the density contrast of the cloud than by the beam Mach number of the jet, and a relativistic jet with low relativistic beam Mach number …

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An Analysis Of The Mos Under Conditions Of Delay, Jitter And Packet Loss And An Analysis Of The Impact Of Introducing Piggybacking And Reed Solomon Fec For Voip, Alexander F. Ribadeneira May 2007

An Analysis Of The Mos Under Conditions Of Delay, Jitter And Packet Loss And An Analysis Of The Impact Of Introducing Piggybacking And Reed Solomon Fec For Voip, Alexander F. Ribadeneira

Computer Science Theses

Voice over IP (VoIP) is a real time application that allows transmitting voice through the Internet network. Recently there has been amazing progress in this field, mainly due to the development of voice codecs that react appropriately under conditions of packet loss, and the improvement of intelligent jitter buffers that perform better under conditions of variable inter packet delay. In addition, there are other factors that indirectly benefited VoIP. Today, computer networks are faster due to the advances in hardware and breakthrough algorithms. As a result, the quality of VoIP calls has improved considerably. However, the quality of VoIP calls …

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Evidence For Production Of Single Top Quarks And First Direct Measurement Of |VTb|, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration May 2007

Evidence For Production Of Single Top Quarks And First Direct Measurement Of |VTb|, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

The D0 Collaboration presents first evidence for the production of single top quarks at the Fermilab Tevatron pp̅ collider. Using a 0.9 fb-1 dataset, we apply a multivariate analysis to separate signal from background and measure σ (pp̅ → tb + X, tqb + X) = 4.9 ± 1.4 pb. The probability to measure a cross section at this value or higher in the absence of a signal is 0.035%, corresponding to a 3.4 standard deviation significance. We use the cross section measurement to directly determine the Cabibbo- Kobayashi-Maskawa matrix element that describes the Wtb coupling …

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Dendrochronological Analysis Of Oak Tree (Quercus) Beams From The Original Schumaker Cabin, Coshocton County, Ohio May 2007

Dendrochronological Analysis Of Oak Tree (Quercus) Beams From The Original Schumaker Cabin, Coshocton County, Ohio

Historic Structures

Dating historical structures in Coshocton County, Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Belding, Elyssa; Wiles, Greg.

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Dendrochronological Analysis Of Oak (Quercus) Tree Cores From The Wilsford Barn, Shreve, Wayne County, Ohio May 2007

Dendrochronological Analysis Of Oak (Quercus) Tree Cores From The Wilsford Barn, Shreve, Wayne County, Ohio

Historic Structures

Dating historical structures in Wayne County, Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Belding, Elyssa; Wiles, Greg

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Synthesis, Reactions, And Applications Of Bis-Ortho-Diynyl Arene (Boda) Monomers, Polymers, And Derivatives, Mark Perpall May 2007

Synthesis, Reactions, And Applications Of Bis-Ortho-Diynyl Arene (Boda) Monomers, Polymers, And Derivatives, Mark Perpall

All Dissertations

Bis-ortho-diynyl arenes (BODA) monomers contain two arenediyne functional groups with variable functionality at both the linker group, X, and the alkyne terminal group, R. These arenediyne moieties undergo thermal Bergman reactions to cycloaromatize to naphthyl diradical species. The inclusion of two of these arenediyne functionalities allows the polymer to grow without losing processability and solubility as most aromatic polymers do. The second functionality acts as a solubilizing group until all functionalities are consumed in the fully cured network polymer.
When heated above 800 °C, BODA polymer converts to a high-yield glassy carbon material. This work has been extended …

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Equitable Efficiency In Multiple Criteria Optimization, Vijay Singh May 2007

Equitable Efficiency In Multiple Criteria Optimization, Vijay Singh

All Dissertations

Equitable efficiency in multiple criteria optimization was introduced mathematically in the middle of nineteen-nineties. The concept tends to strengthen the notion of Pareto efficiency by imposing additional conditions on the preference
structure defining the Pareto preference. It is especially designed to solve multiple criteria problems having commensurate criteria where different criteria values can be compared directly.

In this dissertation we study some theoretical and practical aspects of equitably efficient solutions. The literature on equitable efficiency is not very extensive and provides very limited number of ways of generating such solutions. After introducing
some relevant notations, we develop some scalarization based …

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Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 2. Thermo-Kinematic Model Of Thermochronometer Age Prediction Model, David Whipp Jr, Todd Ehlers, Ann Blythe, Katharine Huntington, Kip Hodges, Douglas Burbank May 2007

Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 2. Thermo-Kinematic Model Of Thermochronometer Age Prediction Model, David Whipp Jr, Todd Ehlers, Ann Blythe, Katharine Huntington, Kip Hodges, Douglas Burbank

Ann Blythe

[1] In the Himalaya and other active convergent orogens, linear relationships between thermochronometer sample age and elevation are often used to estimate long-term exhumation rates. In these regions, high-relief topography and nonvertical exhumation pathways may invalidate such one-dimensional (1-D) interpretations and lead to significant errors. To quantify these errors, we integrate apatite fission track (AFT) ages from the central Himalaya with a 3-D coupled thermokinematic model, from which sample cooling ages are predicted using a cooling-rate-dependent algorithm. By changing the slip partitioning between faults near the Main Central thrust and the Main Frontal thrust system at the Himalayan range front, …

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Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 1. Apatite And Zircon Fission Track And Apatite [U-Th]/He Analyses, Ann Blythe, D Burbank, A Carter, K Schmidt, J Putkonen May 2007

Plio-Quaternary Exhumation History Of The Central Nepalese Himalaya: 1. Apatite And Zircon Fission Track And Apatite [U-Th]/He Analyses, Ann Blythe, D Burbank, A Carter, K Schmidt, J Putkonen

Ann Blythe

No abstract provided.

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Stirling's Approximation, Carl W. David May 2007

Stirling's Approximation, Carl W. David

Chemistry Education Materials

Stirling's approximation is discussed.

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A Reproducible Research Toolkit For R, Roger Peng May 2007

A Reproducible Research Toolkit For R, Roger Peng

Johns Hopkins University, Dept. of Biostatistics Working Papers

We present a collection of R packages for conducting and distributing reproducible research using R, Sweave, and LaTeX. The collection consists of the cacheSweave, stashR, and SRPM packages which allow for the caching of computations in Sweave documents and the distribution of those cached computations via remotely accessible key-value databases. We describe the caching mechanism used by the cacheSweave package and tools that we have developed for authors and readers for the purposes of creating and interacting with reproducible documents.

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A Case Study In Pharmacologic Imaging Using Principal Curves In Single Photon Emission Computed Tomography, Brian S. Caffo, Ciprian M. Crainiceanu, Lijuan Deng, Craig W. Hendrix May 2007

A Case Study In Pharmacologic Imaging Using Principal Curves In Single Photon Emission Computed Tomography, Brian S. Caffo, Ciprian M. Crainiceanu, Lijuan Deng, Craig W. Hendrix

Johns Hopkins University, Dept. of Biostatistics Working Papers

In this manuscript we are concerned with functional imaging of the colon to assess the kinetics of a microbicide lubricant. The overarching goal is to understand the distribution of the lubricant in the colon. Such information is crucial for understanding the potential impact of the microbicide on HIV viral transmission. The experiment was conducted by imaging a radiolabeled lubricant distributed in the subject’s colon. The tracer imaging was conducted via single photon emission computed tomography (SPECT), a non-invasive, in-vivo functional imaging technique. We develop a novel principal curve algorithm to construct a three dimensional curve through the colon images. The …

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Soft Spheres Make More Mesophases, Mattew A. Glaser, Gregory M. Granson, Randall D. Kamien, A. Kosmrlj, Christian Santangelo, P. Ziherl May 2007

Soft Spheres Make More Mesophases, Mattew A. Glaser, Gregory M. Granson, Randall D. Kamien, A. Kosmrlj, Christian Santangelo, P. Ziherl

Christian Santangelo

We use both mean-field methods and numerical simulation to study the phase diagram of classical particles interacting with a hard core and repulsive, soft shoulder. Despite the purely repulsive and isotropic interaction, this system displays a remarkable array of aggregate phases arising from the competition between the hard-core and soft-shoulder length scales, including fluid and crystalline phases with micellar, lamellar, and inverse micellar morphology. In the limit of large shoulder width to core size, we argue that this phase diagram has a number of universal features, and classify the set of repulsive shoulders that lead to aggregation at high density. …

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Exploratory Synthesis And Characterization Of New Mixed-Framework Chalcohalides And Oxyhalide And Its Potential Applications For Diluted Magnetic Semiconductor, Lei Wang May 2007

Exploratory Synthesis And Characterization Of New Mixed-Framework Chalcohalides And Oxyhalide And Its Potential Applications For Diluted Magnetic Semiconductor, Lei Wang

All Dissertations

Due to the excellent diverse properties and performance, solid-state material with low-dimensional crystal structure has always been interested by solid-state scientists. Besides the interesting properties, the low-dimensional-structured materials are used as the platform for further research and application of semiconductor and optical devices, as well as theoretic studies. My dissertation research mainly focuses on two aspects: discovery of solids with low-dimensional crystal structure; fabrication and investigation of new materials using the discovered materials as the platform.
The idea of mixed-anion-framework has been used in synthesis of novel low-dimensional-structured solid-state materials. The stereo-active Sb3+/Bi3+ chalcogenides building units and …

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Bayesian Approach To Three-Arm Non Inferiority Trials, Marcus Chenier Britton May 2007

Bayesian Approach To Three-Arm Non Inferiority Trials, Marcus Chenier Britton

Mathematics Theses

In non-inferiority trials, the goal is to show how an experimental treatment is statistically and clinically not inferior to the active control. The three-arm clinical trial usually recommended for non-inferiority trials by the FDA. The three-arm trial consists of a placebo, reference, and an experimental treatment. The three-arm trial shows the superiority of the reference over the placebo and comparison of the reference to an experimental treatment. In this paper, I will assess a non-inferiority trial with Bayesian methods. By employing Bayesian analysis, the parameters are random and assign vague prior distributions. I will compare the models involving different prior …

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