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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.
141

Characterization of the Mechanosensitivity of Tactile Receptors using Multivariate Logistical Regression

Bradshaw, Sam 30 April 2001 (has links)
Tactile sensation is a complex manifestation of mechanical stimuli applied to the skin. At the most fundamental level of the somatosensory system is the cutaneous mechanoreceptor, making it the logical starting point in the bottom-up approach to understanding the somatosensory system and sensation, in general. Unfortunately, a consensus has not been reached in terms of the afferent behavior of mechanoreceptors subjected to compressive stimulation. In this study, several afferent mechanoreceptors were isolated, mechanically stimulated with controlled compressive loads. Their responses were recorded and the sensitivities of the individual receptors to compressive stimulation were statistically evaluated by correlating the compressive state of the skin to the observed“all-or-nothing" responses. A host of linear techniques have been employed previously to describe this multiple-input, binary-output system; however, each of these techniques has associated shortcomings when employed in this context. In particular, two shortcomings are the assumption of linear system input-output and the inability of the model to assess individual input-output associations relative to concurrent input in a multivariate context with interacting input. Therefore, a non-linear regression technique called logistical regression was selected for characterizing the mechanoreceptor system. From this model, the relative contributions that each component of the stimulus has upon the neural response of the receptor can be quantitatively assessed and extrapolated to the greater population of cutaneous mechanoreceptors. Since this study represents a novel approach to receptor characterization, a framework for the application of logistical regression to the time-series representation of the multiple-input, binary-output mechanoreceptor system was established and validated. Subsequently, in-vitro experiments were performed in which the afferent behavior of tactile receptors in rat hairy skin were recorded and the relative association between a number of biologically meaningful stimulus metrics and the observed neural response was evaluated for each receptor. Through the application of logistical regression, it was determined that cutaneous mechanoreceptors are preferentially sensitive to the rate of change of compressive stress when force-control stimulated and both stress and its rate of change when position-control stimulated.
142

A comparison of multivariate statistical programs available at Kansas State University

Umholtz, Robert L January 2010 (has links)
Digitized by Kansas Correctional Industries
143

Estimation of polychoric correlation for misclassified polytomous variables.

January 2005 (has links)
Yiu Choi Fan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 69-71). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Estimation with Known Misclassification Probabilities --- p.7 / Chapter 2.1 --- Model --- p.7 / Chapter 2.2 --- Maximum Likelihood Estimation --- p.9 / Chapter 2.3 --- Standard Errors of the Parameter Estimates --- p.12 / Chapter 3 --- Numerical Examples (I) --- p.13 / Chapter 3.1 --- Analysis of Real Data --- p.13 / Chapter 3.2 --- Analysis of Artificial Data --- p.16 / Chapter 4 --- Simulation Study (I) --- p.19 / Chapter 4.1 --- Simulation Algorithm --- p.19 / Chapter 4.2 --- Simulation Design --- p.20 / Chapter 4.3 --- Reported Statistics --- p.21 / Chapter 4.4 --- Conclusions of Simulation Results --- p.22 / Chapter 5 --- Estimation by Double Sampling Scheme --- p.24 / Chapter 5.1 --- Introduction of Double Sampling Scheme --- p.24 / Chapter 5.2 --- Model --- p.25 / Chapter 5.3 --- Minimum Chi-square Estimation --- p.26 / Chapter 5.4 --- Statistical Properties of the Parameter Estimates --- p.28 / Chapter 6 --- Numerical Examples (II) --- p.30 / Chapter 6.1 --- "Analysis of Real Data, (2x2 Table)" --- p.30 / Chapter 6.2 --- Analysis of Artificial Data (3x3 Table) --- p.32 / Chapter 7 --- Simulation Study (II) --- p.34 / Chapter 7.1 --- Simulation Algorithm --- p.34 / Chapter 7.2 --- Simulation Design --- p.35 / Chapter 7.3 --- Reported Statistics --- p.37 / Chapter 7.4 --- Conclusions of Simulation Results --- p.38 / Chapter 8 --- Conclusions --- p.39 / Appendices --- p.42 / Chapter A.1 --- The proof of the expression for P(Zj = Ehk) --- p.42 / Chapter A.2 --- The proof of puv and whk{uv) --- p.44 / Chapter A.3 --- The proof of the covariance matrix Q --- p.47 / Chapter A.4 --- The proof of the matrix Σ --- p.52 / Tables A1-A9 --- p.54 / Tables B1-B6 --- p.63 / Bibliography --- p.69
144

Improved estimation of the eigenvalues in a one-sample and two-sample problem.

January 2001 (has links)
Chan Pui Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 103-105). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Main Problems --- p.1 / Chapter 1.2 --- Motivation --- p.5 / Chapter 1.3 --- Present Works --- p.7 / Chapter Chapter 2 --- Estimation of the Eigenvalues in a Wishart Distribution --- p.11 / Chapter 2.1 --- Review of Previous Works --- p.14 / Chapter 2.2 --- Some Useful Statistical and Mathematical Results --- p.17 / Chapter 2.3 --- Improved Estimation of A under Squared Error Loss L1 --- p.23 / Chapter 2.4 --- Simulation Study for the Wishart Distribution under Squared Error Loss --- p.28 / Chapter 2.5 --- Discussions on Wishart Distribution Under Squared Error Loss --- p.32 / Chapter 2.6 --- Improved Estimation of A under the Entropy Loss(det) L2 --- p.33 / Chapter 2.7 --- Simulation Study for the Wishart Distribution Under Entropy Loss L2 --- p.38 / Chapter 2.8 --- Discussions on Wishart Distribution Under Entropy Loss --- p.44 / Chapter Chapter 3 --- Estimation of the Eigenvalues in a Multivariate F Distribution --- p.46 / Chapter 3.1 --- Review of Previous Works --- p.49 / Chapter 3.2 --- Some Useful Statistical and Mathematical Results --- p.50 / Chapter 3.3 --- Improved Estimation of A under the Squared Loss L1 --- p.54 / Chapter 3.4 --- Simulation Study for F Distribution under Squared Error Loss L1 --- p.62 / Chapter 3.5 --- Discussions on F distribution under Squared Error Loss --- p.68 / Chapter 3.6 --- Improved Estimation of A under the Entropy Loss(det) L2 --- p.69 / Chapter 3.7 --- Simulation Study for Multivariate F Distribution under Entropy Loss(det) L2 --- p.76 / Chapter 3.8 --- Discussions on F distribution under Entropy Loss --- p.86 / Chapter Chapter 4 --- Inheritance of Dominance between Eigenvalues Loss Function and Matrix Function --- p.87 / Chapter 4.1 --- Significance of The Problem --- p.87 / Chapter 4.2 --- Inheritance of Dominance between Eigenvalues Estimator and Matrix Estimator under Squared Error Loss --- p.92 / Chapter 4.3 --- Inheritance of Dominance between Eigenvalues Estimator and Matrix Estimator under Entropy Loss --- p.97 / Chapter 4.4 --- Conclusion --- p.102 / BIBLIOGRAPHY --- p.103
145

The analysis of high-dimensional contingency tables with comparable ordinal categories.

January 2003 (has links)
Shum Chun-Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 63-64). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Ordinal Contingency Table --- p.5 / Chapter 2.1 --- Model --- p.5 / Chapter 2.2 --- The Maximum Likelihood Method --- p.7 / Chapter 2.3 --- Limitation of the Maximum Likelihood Estimation in Large Sample --- p.8 / Chapter 2.4 --- The Partition Maximum Likelihood Approach --- p.9 / Chapter 3 --- Modification of the Partition Maximum Likelihood Approach --- p.12 / Chapter 3.1 --- The Modified Partition Maximum Likelihood Approach --- p.12 / Chapter 3.2 --- Mx Implementation --- p.14 / Chapter 3.2.1 --- Maximum Likelihood Procedure --- p.14 / Chapter 3.2.2 --- Modified PML Procedure --- p.15 / Chapter 3.3 --- Examples --- p.16 / Chapter 3.3.1 --- Example 1 : Attitudes of Morality and Equality --- p.16 / Chapter 3.3.2 --- Example 2 : A Panel Model for Political Efficacy --- p.17 / Chapter 3.4 --- Limitation of the Modified PML Approach --- p.19 / Chapter 3.5 --- Simulation Study for the Modified PML Approach --- p.20 / Chapter 4 --- Generalization to Structural Equation Model --- p.22 / Chapter 4.1 --- Model --- p.23 / Chapter 4.2 --- Procedure --- p.24 / Chapter 4.3 --- Examples --- p.26 / Chapter 4.3.1 --- Example 1 : Attitudes of Morality and Equality --- p.26 / Chapter 4.3.2 --- Example 2 : A Panel Model for Political Efficacy --- p.28 / Chapter 5 --- Generalization to Stochastic Constraints on Thresholds --- p.31 / Chapter 5.1 --- Model --- p.32 / Chapter 5.2 --- Bayesian Analysis of the Model --- p.33 / Chapter 5.3 --- Examples --- p.35 / Chapter 5.3.1 --- Example 1 : Attitudes of Morality and Equality --- p.35 / Chapter 5.3.2 --- Example 2 : A Panel Model for Political Efficacy --- p.36 / Chapter 6 --- Conclusion and Discussion --- p.38 / Chapter A --- Mx Script of the ML Estimation - for Example 1 --- p.40 / Chapter B --- Mx Script of the Modified PML Estimation - for Example 1 --- p.42 / Chapter C --- Mx Script of the Modified PML Estimation - for Example 2 --- p.45 / Bibliography --- p.63
146

Multi-sample analysis of latent curve models with longitudinal latent variables.

January 2011 (has links)
Chen, Qiuting. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 71-74). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Bayesian Approach --- p.3 / Chapter 1.3 --- Outline of the thesis --- p.5 / Chapter 2 --- Model Descriptions --- p.6 / Chapter 2.1 --- Basic Latent Curve Models --- p.6 / Chapter 2.2 --- Latent Curve Models with Exogenous Latent Variables --- p.8 / Chapter 2.3 --- Latent Curve Models with both Exogenous Variables and Longitudinal La- tent Variables --- p.9 / Chapter 2.4 --- multisample analysis --- p.12 / Chapter 3 --- Bayesian Estimation and Model Comparison --- p.18 / Chapter 3.1 --- Bayesian analysis for parameter estimation --- p.18 / Chapter 3.2 --- Bayesian model comparison --- p.27 / Chapter 4 --- A simulation study --- p.31 / Chapter 4.1 --- Simulation for parameter estimations --- p.31 / Chapter 4.2 --- Simulation for model comparison using DIC --- p.35 / Chapter 5 --- An illustrative example --- p.47 / Chapter 5.1 --- Background introduction --- p.47 / Chapter 5.2 --- Some firm-specific factors that may affect the capital structure --- p.49 / Chapter 5.3 --- Real data illustration --- p.52 / Chapter 6 --- Conclusion and further discussion --- p.65 / Appendix --- p.67 / Chapter 7 --- Appendix: equation derivation --- p.67 / Bibliography
147

Clustering multivariate data using interpoint distances.

January 2011 (has links)
Ho, Siu Tung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 43-44). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 2 --- Methodology and Algorithm --- p.6 / Chapter 2.1 --- Testing one. homogeneous cluster --- p.8 / Chapter 3 --- Simulation Study --- p.17 / Chapter 3.1 --- Simulation Plan --- p.19 / Chapter 3.1.1 --- One single cluster --- p.19 / Chapter 3.1.2 --- Two separated clusters --- p.20 / Chapter 3.2 --- Measure of Performance --- p.26 / Chapter 3.3 --- Simulation Results --- p.27 / Chapter 3.3.1 --- One single cluster --- p.27 / Chapter 3.3.2 --- Two separated clusters --- p.30 / Chapter 4 --- Conclusion and further research --- p.36 / Chapter 4.1 --- Constructing Data depth --- p.38 / Bibliography --- p.43
148

Multivariate process control with input-output relationships for optimal process control

Pemajayantha, V., University of Western Sydney, Nepean, Faculty of Commerce, School of Quantitative Methods and Mathematical Sciences January 1998 (has links)
This thesis examines the existing theories and applications of Multivariate Statistical Process Control, outlines areas of difficulty and proposes a new technique of multivariate process control chart with input-output relationship for optimal process control. The process control techniques developed up to the present time focused on the fast detection of out-of-control signals, and achieved considerable success in that respect. The techniques reported on multivariate process control thus far include extensions of univariate process control charts to their multivariate counterparts, ranging from classical Shewharts charts to modern Cumulative Sum Process Control charts. Alternative approaches in this area include Principal Component Approach, Partial Regression approach, Baysian modelling and sequential tests on detection of change points. Although each method has its own limitation, these new developments have significantly contributed to the achievement of a constant high quality of products and services. The techniques of process control are yet incomplete. They require continuous attention, as production and service technologies are being continuously developed.In particular, the level of automation, re-engineering of production processes and ever demanding economic optimality of technology demand the re-engineering of statistical process control. The CFM chart developed in this thesis would open the door to this area of science and lays a critical foundation for future research / Doctor of Philosophy (PhD)
149

Determining an urban water consumption model based on socio-demographic factors

Cheruseril, Jimmy Jose, jimmy.cheruseril@rmit.edu.au January 2007 (has links)
Water is a limited and essential resource for living and its importance is understood by all. Water is a scarce resource in Australia. Many of the river basins in Australia cover only a small area and the rivers that drain them are seasonal in flow. Climate change coupled with increasing population and a growing economy has put stress on the existing water resources. In the period of drought between 2003 and 2005 the careful consumption of water was of high importance and there is a consequent need to develop new methods to use water wisely. The state and federal governments have initiated many campaigns over the past decade to reduce water consumption and conserve water. This thesis aims to identify the relationship between socio-demographic factors and water consumption using multivariate analysis techniques and geographic information systems (GIS). This thesis has examined the water consumption patterns of Metropolitan Melbourne on a postcode level during the period 2000-2005. It has investigated how these patterns have altered with time and examined whether or not these changes are geographically linked. The effectiveness of the advertising campaigns and educational programs undertaken during the study period by The Victorian Government and its impact on Melbourne's water usage has been evaluated. Moran's I statistic was performed using water consumption to find spatial autocorrelation among postcodes. Multivariate techniques of factor and regression analysis were used to develop a model based on socio-demographic predictors to estimate water consumption. The relationship between separate dwellings, business counts, distance from GPO, semi detached dwellings and academically less qualified residents has been identified in this study. The numbers of separate dwellings and businesses have a significant influence on water consumption. Water use and soci o-demographic data are visualised by the creation of thematic maps using GIS.
150

Some aspects of longitudinal data analysis / Peter J. Ricci.

Ricci, Peter J. (Peter Joseph) January 1994 (has links)
Bibliography: leaves 173-188. / vii, 188 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Statistics, 1994

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