by Kwan Hok-wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 67-69). / Abstracts in English and Chinese. / Acknowledgment --- p.i / Abstract --- p.ii / Chapter 1. --- INTRODUCTION / Chapter 1.1 --- Chemical speciation of cyanide --- p.1 / Chapter 1.2 --- Review of analytical techniques for cyanide determination --- p.3 / Chapter 1.3 --- Importance of sediment in the environment --- p.6 / Chapter 1.4 --- Characteristics of marine sediment --- p.6 / Chapter 1.5 --- Antropogenic sources of cyanide --- p.7 / Chapter 1.6 --- Research objective --- p.8 / Chapter 1.7 --- Brief description of the project --- p.9 / Chapter 2. --- INSTRUMENTATION AND THEORY / Chapter 2.1 --- Instrumentation for flow injection analysis system --- p.11 / Chapter 2.2 --- Basic principles of flow injection analysis --- p.21 / Chapter 2.3 --- Basic principles of amperometric detection --- p.24 / Chapter 3. --- EXPERIMENTAL / Chapter 3.1 --- Instrumentation --- p.25 / Chapter 3.2 --- Reagents --- p.32 / Chapter 3.3 --- Sample preparation --- p.34 / Chapter 4. --- RESULTS AND DISCUSSION / Chapter 4.1 --- Effect of bismuth on on-line precipitation of sulphide in FIA --- p.37 / Chapter 4.2 --- Calibration --- p.37 / Chapter 4.3 --- Effectiveness of the distillation conditions --- p.41 / Chapter 4.4 --- Comparisons of cyanide extraction methods for sediment analysis --- p.42 / Chapter 4.5 --- Effect of bismuth nitrate on cyanide recoveries --- p.45 / Chapter 4.6 --- Effect of bismuth nitrate on cyanide recoveries in the presence of sulphide --- p.48 / Chapter 4.7 --- Effect of bismuth nitrate on recoveries of total cyanide in the analysis of interlaboratory test samples --- p.55 / Chapter 4.8 --- Recoveries of complexed cyanide in the analysis of SETOC sample with sulphide interference --- p.57 / Chapter 4.9 --- Analysis of marine sediment samples --- p.58 / Chapter 4.10 --- Recovery tests and precision studies --- p.59 / Chapter 4.11 --- Interferences --- p.62 / Chapter 5. --- CONCLUSION --- p.66 / Chapter 6. --- REFERENCES --- p.67

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

published_or_final_version / Chemistry / Master / Master of Philosophy

No description available.

An empirical approach to the study of phosphine compounds was completed using Molecular Mechanics 2 (MM2), and several computer programs written to descibe and analyze the final geometric orientations of the molecules. The calculations were performed on 64 conformers of 16 different phosphines. Results from these calculations were compared to those previously obtained for MNDO and MINDO/3 calculations, and to experimental data. Cone angles calculated from the MM2 optimized geometries, were compared to Tolman's original work, and to values obtained from semiempirical calculations, and to experimental results. In general, it was found that weighted average cone angles best represent the size of phosphine ligands. / Department of Chemistry

Thesis (Ph.D.)--Baylor University, 2007. / Includes bibliographical references (p. 96-98).

Thesis (Ph. D.)--University of Florida, 1981. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 108-109).

In recent years, high-dimensional data sets are widely available in many scientific areas, such as gene expression study, finance and others. Estimating the covariance matrix is a significant issue in such high-dimensional data analysis. This thesis focuses on high-dimensional covariance matrix estimation and its application. First, this thesis focuses on the covariance matrix estimation. In Chapter 2, a new optimal shrinkage estimation of the covariance matrices is proposed. This method is motivated by the quadratic discriminant analysis where many covariance matrices need to be estimated simultaneously. We shrink the sample covariance matrix towards the pooled sample covariance matrix through a shrinkage parameter. Some properties of the optimal shrinkage parameter are investigated and we also provide how to estimate the optimal shrinkage parameter. Simulation studies and real data analysis are also conducted. In Chapter 4, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, a total of nine covariance matrix estimation methods will be considered for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. A few practical guidelines are also made on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this chapter also serves as a proxy to assess the performance of the covariance matrix estimation. Second, this thesis focuses on the application of high-dimensional covariance matrix estimation. In Chapter 3, we consider to estimate the high-dimensional covariance matrix based on the diagonal matrix of the sample covariance matrix and apply it to the Hotelling’s tests. In this chapter, we propose a shrinkage-based diagonal Hotelling’s test for both one-sample and two-sample cases. We also propose several different ways to derive the approximate null distribution under different scenarios of p and n for our proposed shrinkage-based test. Simulation studies show that the proposed method performs comparably to existing competitors when n is moderate or large, and it is better when n is small. In addition, we analyze four gene expression data sets and they demonstrate the advantage of our proposed shrinkage-based diagonal Hotelling’s test. Apart from the covariance matrix estimation, we also develop a new classification method for a specific type of high-dimensional data, RNA-sequencing data. In Chapter 5, we propose a negative binomial linear discriminant analysis for RNA-Seq data. By Bayes’ rule, we construct the classifier by fitting a negative binomial model, and propose some plug-in rules to estimate the unknown parameters in the classifier. The relationship between the negative binomial classifier and the Poisson classifier is explored, with a numerical investigation of the impact of dispersion on the discriminant score. Simulation results show the superiority of our proposed method. We also analyze four real RNA-Seq data sets to demonstrate the advantage of our method in real-world applications. Keywords: Covariance matrix, Discriminant analysis, High-dimensional data, Hotelling’s test, Log determinant, RNA-sequencing data.

Bibliography: pages 117-120. / A series of para-phenyl substituted N,N-dialkyl-N'-benzoylthioureas where para-phenyl substituents are H, Cl, Br, I, NO₂ and OCH₃ and alkyl chains are -CH₂CH₃, -(CH₂)₃CH₃ and and -CH₂C₆H₅ as well as their corresponding neutral bis complexes of type cis [ML₂] where M = Pd(II) and Pt(II) have been prepared and characterized. The structures of these compounds has been studied using high resolution nuclear magnetic resonance technique. Studies were also carried out to investigate possible use of these N,N-dialkyl-N-benzoylthioureas as ligands suitable for the chromatographic separation of Pt(II), Pd(II), Ni(II) and Cu(II). To this end the possible selective extraction of these complexes from acidic aqueous phases was examined. This layer normal phase chromatography has been mainly used, using a variety of organic phases as eluent. A preliminary investigation of the suitability of using normal phase HPLC for the separation of the platinum and palladium complexes was undertaken.

In this dissertation, we investigate the Riccati diagonal stability and explore some extensions of this notion. Riccati diagonal stability plays an important role in the stability analysis of linear time-delay systems. It is known that if a linear time-delay system is Riccati diagonally stable then it admits a diagonal Lyapunov-Krasovskii functional. The existence of such a functional implies the asymptotic stability of the linear time-delay system. This diagonal stability problem has other applications in applied areas such as physical sciences and population dynamics. We also study the Lyapunov diagonal stability, which has a clear connection to the Riccati diagonal stability. Using a separation theorem, we first provide new proofs for some existing results on the Lyapunov-type diagonal stability. We also construct a new, shorter, and more transparent proof for a well-known result by Kraaijevanger that gives explicit conditions for the Lyapunov diagonal stability on matrices in $\mathbb{R}^{3 \times 3}$. In addition, we give several necessary and sufficient conditions for matrices in $\mathbb{R}^{3 \times 3}$ to be Lyapunov diagonally stable. Furthermore, we present an extension of the so-called Riccati diagonal stability to the Riccati $\alpha$-scalar stability. We derive two new characterizations regarding the Riccati $\alpha$-scalar solution of the Riccati matrix inequality so as to expand and broaden the relevant existing results. We also generalize this notion to consider a common $\alpha$-scalar solution for a family of Riccati matrix inequalities. We shall refer to this new generalization as common Riccati $\alpha$-scalar stability. As an application for the main results, we further explore families of block triangular matrices. Finally, motivated by recent developments, we formulate the problem of Riccati $\alpha$-stability. We present a necessary and sufficient condition for this type of stability and study the connection between Riccati $\alpha$-stability of a pair of $\alpha$-block matrices and Riccati stability of the diagonal block pairs. Moreover, we generalize the Riccati $\alpha$-stability by considering a family of pairs of $\alpha$-block matrices and give a new characterization for this new case.