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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

The development of test procedures for controlling the quality of the manufacture of engineered compression stockings

Moghaddassian Shahidi, Arash January 2010 (has links)
A new technology platform known as 'Scan2Knit' was invented in the William Lee innovation Centre of the University of Manchester to engineer and manufacture compression stockings for the treatment of venous disease in a Welcome Trust funded research project. The intellectual property of the above technology has been licensed for commercial exploitation by the University.The graduated pressure profile that is necessary for the treatment of venous ulcers is generated with the engineered compression stocking, and will depend on the stitch length of the knitted fabric structure and an empirical pressure profile database. The 'Scan2Knit' technology was developed to produce an engineered compression stocking on a 18 gauge Stoll CMS computerised flat-bed knitting machine utilising a microprocessor controlled precision positive yarn delivery system to guarantee the delivery of a predetermined stitch length to the knitting needles. However, the licensee of the technology has decided to manufacture engineered compressions stockings by using 14 gauge Stoll CMS flat-bed knitting machines instead of gauge 18 machines due to commercial advantages. Therefore, the main aim of this work is to investigate the transfer of 'Scan2Knit' technology on to a coarse gauge manufacturing platform to produce engineered compression stockings. The investigation focuses on two vital requirements of 'Scan2Knit' technology; the analysis of the performance of the precision positive yarn delivery system on the new production platform and the evaluation of the functionality of the knitted structure produced with it. The objectives of the research are to develop test procedures for the evaluation of the three dimensional pressure characteristic of compression stockings manufactured on the new production platform, and the performance of the precision yarn delivery system. To produce the engineered compression stockings with the 'Scan2Knit' technology, it is essential to determine the interface pressure that the knitted structure would impart on a particular radius of curvature at a predetermined strain percentage which is attained with an empirical database. Hence, a key objective of this study is to develop a methodology, which is efficient and user friendly, for the generation of the empirical pressure profile database required to engineer the interface pressure profile of a compression stocking.It is envisioned that the manufacturer of the engineered compression stockings would benefit by the knowledge generated within this research, and develop their own quality assurance procedures to guarantee that the compression stockings are produced to deliver the graduated pressure profile prescribed by the clinician for the treatment of venous ulcers.
72

Statistical inferences for missing data/causal inferences based on modified empirical likelihood

Sharghi, Sima 01 September 2021 (has links)
No description available.
73

Model for dilution control applying empirical methods in narrow vein mine deposits in Peru

Salgado-Medina, Luis, Núñez-Ramírez, Diego, Pehovaz-Alvarez, Humberto, Raymundo, Carlos, Moguerza, Javier M. 01 January 2019 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Empirical methods play an important role in the field of geomechanics due to the recognized complexity of the nature of rock mass. This study aims to analyze the applicability of empirical design methods in vein-shaped hydrothermal mining deposits (narrow vein) using Bieniawski and Barton classification systems, Mathews stability graphs, Potvin and Mawdesley geomechanics classification systems, and mining pit dilution based on the equivalent linear overbreak/slough (ELOS). In most cases, these methods are applied without understanding the underlying assumptions and limits of the database in relation to the inherent hidden risks. Herein, the dilutions obtained using the empirical methods oscillate between 8% and 11% (according to the frontal dimension), which are inferior to the operative dilution of the mine at 15%. The proposed model can be used as a practical tool to predict and reduce dilution in narrow veins.
74

An Empirical Analysis of Demand Interrelationships: An Application to Selected Agricultural Commodities in Venezuela

Brito, Hector Luis Mata 01 May 1970 (has links)
The primary objective of this study was to develop demand equations at retail for selected Venezuelan food commodities. Commodities included for analysis were rice, refined sugar, crude sugar, flour, potatoes, beef, pork, black beans, corn, and powdered milk. The basic statistical technique employed in the analysis was least squares multiple regression. Although several mathematical forms for these demand equations were evaluated, a log-log transform was found to be most useful. Independent variables included own price, prices of substitutes and complements, time and income . Observations were taken from Venezuelan time series data over the period 1945-1965. Development of these basic demand equations facilitated the treatment of a second objective which was to evaluate the degree of complementarity and substitution between each one of the commodities included in the model. Further, it provided the necessary structural framework to give exante examination to selected policy alternatives for Venezuelan agriculture. Alternatives examined included minimwn price and import policies. Interesting results and conclusions may be s ummarized as follows: 1. Difficult statistical problems are encountered in an attempt to estimate direct and cross elasticities of demand from time series data . 2 . A less general approach utilizing principles of demand theory is advisable until further requirements are made in the data series. 3. A consistent demand model docs provide useful insights into the interrelationships of commodity demands in terms of direction of change in price and quantity if not in terms of their magnitude. 4. Regional and social stratification of price, income and consumption data should improve the reliability of any subsequent analyses . 5. Additional household expenditure surveys of a cross-sectional nature would provide useful and necessary checks on the demand estimates obtained from time series data.
75

Property Tax Capitalization: Theory and Empirical Evidence

Lillywhite, Jay M. 01 May 1994 (has links)
In an environment of increasing government expenditures financed largely viii through taxes, including a relatively visible and large residential property tax, the issue of whether property taxes are capitalized into market values is increasingly important. Property tax capitalization is the reflection of property taxes in the value of real property. The capitalization of property tax does not necessarily pose a problem; rather, problems arise when homes identical to each other have different taxes and these differentials are then capitalized into market values. These capitalized tax differentials result in large capital gains and losses to owners of real estate. This study (1) reviews existing economic theory and empirical evidence on the capitalization of property taxes, (2) develops a model of property valuation inclusive of tax effects, and (3) estimates the parameters of this model using a comprehensive data set of over 334 home sales in the Logan, Utah area. The empirical results include an estimate of the tax capitalization effect. Two closely related issues are also addressed in the study. They include: (I) changes in real estate prices, including a suggested method for measuring such change and (2) a study of property tax equity, including two specific measures of tax fairness. The conclusions are (I) tax differentials are capitalized; (2) real estate prices in the study area increased approximately 10 percent per year from 1989 to 1992; and (3) there is significant variation in assessment ratios.
76

Statistical Inferences on Inflated Data Based on Modified Empirical Likelihood

Stewart, Patrick 06 August 2020 (has links)
No description available.
77

An Empirical Investigation of Economic Aspects of Physician Services Utilization

McLeod, Logan Carter 12 1900 (has links)
<p> This thesis is an empirical exploration into a range of issues related to the economics of the utilization of physician services. Physicians play an important role in a health care system as physicians are a patient's primary point of contact with the health care system and physicians are predominantly responsible for directing how patients use other health care resources. In particular, physicians are at the center of Canada's universal public insurance system with first dollar coverage for medically necessary physician and hospital services.</p> <p> The thesis comprises three separate essays. The first essay has a methodological focus on statistically modeling and predicting the use of general practitioners (GPs) when use is measured as the number of GP visits. The essay compared a state-of-the-art parametric latent class negative binomial model to a nonparametric kernel conditional density estimator, and evaluated how well each was able to fit the observed data and predict physician use.</p> <p> The second and third essays look at more substantive policy questions. The second essay investigates how the supply of GPs and specialists affects the mix of physician services received by individuals. A persistent concern in many health care systems is how variations in the supply of physicians will impact the use of physician services. The results suggest concerns about concerns of patient access and receipt of care in the presence of a shortage of specialists may be mitigated, all else equal, if patients are able to substitute GP services for specialist services.</p> <p> The third essay examines income-related inequity in the use of physician services by asthmatics and diabetics, relative to the general population, and the contributions of different factors to income-related inequality using the concentration index approach.</p> / Thesis / Doctor of Philosophy (PhD)
78

The Spatial Pattern of Urban Residential Blight

Mercer, John 05 1900 (has links)
<p> This thesis seeks to describe and explain the spatial pattern of urban residential blight. The empirical analysis is limited to one study area; that of the Chicago metropolitan area. The data are U.S. Census data for census tracts in 1940, 1950, and 1960. Following a review of pertinent literature, an attempt is made to conceptualise the process that generates residential blight. From this conceptual framework, a number of hypotheses are developed concerning the relationship between residential blight and selected socio-economic variables. Other relationships are derived from an interpretation of maps of residential blight in the Chicago area for the different time periods. The hypotheses are tested using such multivariate procedures as principal components analysis, and regression and correlation analysis. The thesis also contains an application of the Blalock-Simon procedure for causal modelling to the Chicago data. The findings of the empirical analysis are related to present knowledge concerning urban residential blight. </p> / Thesis / Doctor of Philosophy (PhD)
79

Essays on Empirical Dynamic Stochastic General Equilibrium Models

Hou, Keqiang 09 1900 (has links)
<p> The overall goal of this thesis is to provide a deeper understanding of the role of dynamic stochastic general equilibrium (DSGE) models as foundations upon which empirical work is conducted. This is a very broad topic with a large existing literature. For this purpose, my dissertation focuses on applying the tools and rich structure of DSGE models to answer questions that have hitherto been studied only by using a reduced-form characterization. I have chosen to look at two specific macroeconomic questions of interest: the economic consequences of oil price shocks in Canada and the role of intangible capital (IC) in explaining cyclical dynamics of S&P500 earnings. Chapter 2 look at the economic consequences of oil price shocks in a structural vector autoregressions (VAR) framework. Chapter 3 builds on this by developing an open economy DSGE model to investigate the impact of oil price shocks on the aggregate Canadian economy and to quantify the relative contribution of U.S. and Canadian monetary policy in transmitting oil price shocks. Chapter 4 studies another interesting macroeconomic phenomenon: the excess volatility of aggregate profits. We embed intangible capital into an otherwise standard real business cycle (RBC) model to examine the role of intangible capital in driving cyclical dynamics of S&P500 earnings. A common feature of my papers is the application of Bayesian time series techniques to macroeconomic data to pursue new insights on "the impact of oil price shocks on economic activities", "the role of monetary policy in transmitting oil price shocks" in new open economic macroeconomics (NOEM) literature and "intangible capital and corporate earnings" in U.S. business cycle literature.</p> / Thesis / Doctor of Philosophy (PhD)
80

Three Essays on the Economics of Immigration

Tu, Jiong 01 1900 (has links)
<P> The three essays in this thesis conduct empirical research on the economics of immigration using data from the Canadian Censuses. In the first paper, I analyze the impact of immigration on native-born Canadians' wage growth by combining an area approach and a skill approach. The estimated effects of immigration from both a first difference regression and a two-stage regression are either statistically insignificant or significantly positive. The results indicate that there is no evidence for a negative impact of the large immigrant influx during the 1990s on the wage growth of natives. The second essay examines the impact of residence in an ethnic enclave on male immigrants' labour force activities. For recent immigrants who arrived in Canada within ten years, the intensity of enclave residence is found to be negatively associated with their labour force participation rate, but positively correlated with their employment probability. However, living in an enclave has no significant effect on the labour force activity of old immigrants whose years-since-migration is more than twenty. These findings are robust to probit and instrumental variable estimations. In the third essay, I examine the returns to education for first, second and third generation immigrant men. Multivariate regression results indicate that the third generation with at least postsecondary education earn more than the equally educated first and second generations. However, the third generation do not have a wage premium over the second generation when they have high school education and lower. I explain the well-educated second generation's difficulty in translating their intellectual ability into productivity by their ethnic and linguistic distance from the Canadian mainstream, and by negative city-specific effects. I then suggest that immigrant assimilation policies that target the well-educated first and second generations should be designed to promote the acceptance of their human capital by the Canadian labour market. </p> / Thesis / Doctor of Philosophy (PhD)

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