Numerical solutions of nonlinear elliptic problem using combined-block iterative methods

This thesis is concerned with iterative and monotone methods for numerical solutions of nonlinear elliptic boundary value problems. The methods we study here are called block iterative methods, which solve the nonlinear elliptic problems in twodimensional domain in R2 or higher dimensional domain in Rn. In these methods the nonlinear boundary value problem is discretized by the finite difference method. Two iteration processes, block Jacobi and block Gauss-Seidel monotone iterations, are investigated for computation of solutions of finite difference system using either an upper solution or a lower solution as the initial iteration. The numerical examples are presented for both linear and nonlinear problems, and for both block and pointwise methods. The numerical results are compared and discussed

Functionalized carbon nanomaterials: exploring the interactions with Caco-2 cells for potential oral drug delivery

Although carbon nanomaterials (CNMs) have been increasingly studied for their biomedical applications, there is limited research on these novel materials for oral drug delivery. As such, this study aimed to explore the potential of CNMs in oral drug delivery, and the objectives were to evaluate CNM cytotoxicity and their abilities to modulate paracellular transport and the P-glycoprotein (P-gp) efflux pump. Three types of functionalized CNMs were studied, including polyhydroxy small-gap fullerenes (OH-fullerenes), carboxylic acid functionalized single-walled carbon nanotubes (f SWCNT-COOH) and poly(ethylene glycol) functionalized single-walled carbon nanotubes (f SWCNT-PEG), using the well-established Caco-2 cell monolayer to represent the intestinal epithelium. All three CNMs had minimum cytotoxicity on Caco-2 cells, as demonstrated through lactose dehydrogenase release and 3-(4,5-dimethyliazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Of the three CNMs, f SWCNT-COOH significantly reduced transepithelial electrical resistance and enhanced transport of Lucifer Yellow across the Caco-2 monolayer. Confocal fluorescence microscopy showed that f SWCNT-COOH treated cells had the highest perturbation in the distribution of ZO-1, a protein marker of tight junction, suggesting that f SWCNT-COOH could enhance paracellular permeability via disruption of tight junctions. This modulating effect of f SWCNT-COOH can be reversed over time. Furthermore, cellular accumulation of the P-gp substrate, rhodamine-123, was significantly increased in cells treated with f SWCNT-COOH, suggestive of P-gp inhibition. Of note, f SWCNT-PEG could increase rhodamine-123 accumulation without modifying the tight junction. Collectively, these results suggest that the functionalized CNMs could be useful as modulators for oral drug delivery, and the differential effects on the intestinal epithelium imparted by different types of CNMs would create unique opportunities for drug-specific oral delivery applications

Mixed anova model analysis of microarray experiments with locally polled error

The determination of a list of di®erentially expressed genes is a basic objective in many cDNA microarray experiments. Combining information across genes in the statistical analysis of microarray data is desirable because of relatively small number of data points obtained for each individual gene. Our LPE approach ¯nds a middle ground between global F test and gene-speci¯c F test by pooling the information across a group of genes that have similar variance estimates and shrinks the within- gene variance estimate towards an estimate including more genes. This method provides a powerful and robust approach to test di®erential expression of genes but does not su®er from biases of the global F test and low power of gene-speci¯c F test. In our approach the two-stage Mixed ANOVA model provides a conceptually and computationally e±cient means to analyze the microarray data

The effects of China’ s VAT enlargement reform on the income redistribution of urban households

Background: China's former goods and service tax (GST) system subjects sale of goods to VAT and provision of services to business tax. The VAT enlargement reform launched in 2012 aimed to replace the business tax with VAT step by step. This paper is intended to explore the redistribution effects of this reform. Methods: On basis of input-output model and statutory tax rates, this paper derives the measurement of full GST burden of households in China where both VAT and business tax are imposed. Using the 2012 urban household survey data, the redistribution effects of the VAT enlargement reform is estimated by comparing the Gini coefficient and general entropy indexes before and after the reform. Results: The VAT enlargement reform has improved the redistribution effects of China's GST system mainly through lowering the average tax burden and reducing the inequality within the lowest-income group, though the inequality among different income groups was not reduced considerably. Conclusions: Compared with overall rate reduction, greater relief to necessity items could improve the redistribution effects of the future VAT system more effectively

MODELING VECTOR TIME SERIES DATA

In this dissertation, firstly, I study spatial quantile regression estimation of mul- tivariate threshold time series models. Asymptotic normality of the proposed spatial quantile regression estimator is established. Simulations and a real example are used to evaluate the performance of the proposed estimator. Secondly, I study the multi- variate time-varying coefficient models for time series data. An explicit solution of the coefficient estimators is given in the paper. Furthermore, I propose generalized likelihood ratio test for the multivariate time-varying coefficient models, my aim is to construct some test statistics to test whether the coefficients are constants or of some specific parametric functional for the time-varying coefficient model. The asymptotic null distribution of the proposed test statistics is presented and shown to be independent of the nuisance parameters. Simulation results for the power of the test and a real example are reported at the end of this dissertation

A system for computational analysis and reconstruction of 3D comminuted bone fractures

High energy impacts at joint locations often generate highly fragmented, or comminuted bone fractures. A leading current approach for treatment requires physicians qualitatively to classify the fracture to one of four possible fracture severity cases. Each case then has a sequence of best-practices for obtaining the best possible prognosis for the patient. It has been observed that qualitative evaluation of fracture severity by physicians can vary significantly which can lead to potential mis-classification and mis-treatment of these fracture cases. Major indicators of fracture severity are (i) fracture surface area, i.e., how much surface area was generated when the bone broke apart and (ii) dispersion, i.e., how far the fragments have rotated and translated from their original anatomic positions. Work in this dissertation develops computational tools that solve the bone puzzle-solving problem automatically or semi-automatically and extract previously unavailable quantitative information for these indicators from each bone fragment that are intended to assist physicians in making a more accurate and reliable fracture severity classification. The system applies novel three-dimensional (3D) puzzle-solving algorithms to identify the fracture fragments in the CT image data and piece them back together in a virtual environment. Doing so provides quantitative values for both fracture surface area and dispersion that reduce variability in fracture severity classifications and prevent mis-diagnosis for fracture cases that may be difficult to qualitatively classify using traditional approaches. This dissertation describes the system, the underlying algorithms and demonstrates the virtual reconstruction results and quantitative analysis of comminuted bone fractures from six clinical cases

Evidencing sensemaking: a speech act theory study of metaphors in organizational mission statements

This study explores how metaphors deployed in university mission statements demonstrate the sensemaking process of organizational reality. One hundred thirty-two mission statements collected across the University of North Carolina system comprise the textual source of analysis for this study. Austin and Searle's speech act theory is employed to intertextually identify metaphors, which are then analyzed in line with Weick's framework of sensemaking. The elements of the sensemaking process are evidenced in hierarchical metaphors: (i) environment-screening: "environment as change (organizations as positioned, time-pacer, and wind-catcher);" (ii) enactment: "enactment as changer (the university as a plate of loose sand, professional, and mission-setter);" (iii) selection: "organization as relevance-maker (the university as teacher, researcher, server, strategist, and goal-hitter);" (iv) retention: "organization as retainer (the university as value-keeper and role-player (center, community, leader, and leader-preparer);" and (v) remembering: "organization as rememberer (the university as history-defender and principle-observer)." Together, they comprise metaphors we make sense by. By vividly framing forms, such metaphors enrich our knowledge about the organizational reality, the mission statements, the association of teaching, research and service, the relationship between the sensemaking elements, and the heuristic and ongoing nature of sensemaking

Metal (manganese) oxide based nano-architectures and supercapacitor materials in energy storage applications

This study describes the growth mechanism, magneto-capacitance enhancement and separator-free design of a-MnO2 on super-aligned electrospun carbon nanofibers (SA-ECNFs) as electrode materials for supercapacitor energy storage. The morphology of the SA-ECNFs/MnO2hybrid electrodes were investigated by scanning electron microscope (SEM). The composite and crystal information was characterized by X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDX) and X-Ray Diffraction Spectroscopy (XRD). The energy storage performance was tested by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charging/discharging techniques. A time-dependent MnO2 film growth analysis suggests a three-step kinetics mechanism for the electrodeposition of MnO2 on SA-ECNFs and a self-cessation ending. The SA-ECNFs/MnO2 hybrid electrodes provide with high specific capacitance energy storage. The MnO2-modified ECNFs electrode presents mT magneto-energy storage enhancement ability due to the polarization of unpaired electrons’ contribution in increased pseudocapacitance. Manipulation of the thickness of MnO2 film suggests an ultra-thick MnO2 coating capable for separator-free configuration for a supercapacitor. A bi-functional model of the MnO2 film is proposed to explain its potential to assemble a device without the use of separator, which, for the first time, demonstrates the supercapacitance energy storage

The influence of privacy awareness and privacy self-efficacy in e-commerce

During the past decade, the Internet has become an essential tool for, among other things, communication, entertainment, and business. Especially notable is how it has changed the way business is conducted. Online information technology has profoundly affected markets and transactions. In line with the increasing use of online shopping, users have continued to expand their knowledge of the Internet. They have become more confident in this knowledge, and their self-initiated efforts at online privacy also appear to have matured. Users have expressed their unease about privacy when making online purchases, and it has been found that more than three-quarters of users basically agree they will not use services, products, or retailers if they feel their privacy is in danger of being violated. The present study helps to better understand the perceived benefits and concerns surrounding online purchasing. It applies self-efficacy theory to identify online privacy-related self-efficacy, and evaluate its influence on online purchasing intent. The study results show that awareness of online privacy influences the intent to use online shopping services. It was also found that experience using online services decreases users’ tendencies to use such services in the future. This study will help to better understand the perceived benefits and concerns surrounding online purchasing

Teaching the basic violin bowing technique : a comparative study of bowing technique of selected violin schools from 1751 to 1974

Although much has been written on the history of violin playing and violin-playing techniques, comparative studies of bowing techniques can seldom be found. Comparative discussion of pedagogic materials, in particular, is even rarer. This study presents a number of possibilities in teaching violin bowing technique by surveying and comparing the teaching methods of master teachers of different periods. Geminiani, L. Mozart, and L'Abbe le fils have been chosen as representatives of the eighteenth century. Baillot and Spohr represent the nineteenth century. The twentieth-century representatives include Auer, Flesch, Galamian, and Rolland. Their methods reflect the impact of the development of the construction of the bow, of musical trends, and of personal performing styles