In this dissertation we developed theoretical models to analyse Gaussian and multinomial distributions. The analysis is focused on classification in high dimensional feature spaces and provides a basis for dealing with issues such as data sparsity and feature selection (for Gaussian and multinomial distributions, two frequently used models for high dimensional applications). A Naïve Bayesian philosophy is followed to deal with issues associated with the curse of dimensionality. The core treatment on Gaussian and multinomial models consists of finding analytical expressions for classification error performances. Exact analytical expressions were found for calculating error rates of binary class systems with Gaussian features of arbitrary dimensionality and using any type of quadratic decision boundary (except for degenerate paraboloidal boundaries). Similarly, computationally inexpensive (and approximate) analytical error rate expressions were derived for classifiers with multinomial models. Additional issues with regards to the curse of dimensionality that are specific to multinomial models (feature sparsity) were dealt with and tested on a text-based language identification problem for all eleven official languages of South Africa. / Thesis (M.Ing. (Computer Engineering))--North-West University, Potchefstroom Campus, 2009.

Despite the huge national energy resources, many Nigerians do not have access to high quality, modern energy services. For those with access, energy supply lacks reliability, especially in the case of liquefied petroleum gas (LPG). Hence this research considers the possibility of enhancing the household use of LPG. It analyzes the factors affecting the current demand and supply. Salient features of the LPG supply and distribution system were also discussed. On the basis of the existing situation, barriers of increasing LPG use, in particular, the problems regarding affordability, priCing, government poliCies, safety, transportation and distribution were analyzed and identified statistically using the chi-square statistical method as a tool. Finally, on the basis of the challenges identified, suggestions and recommendations were made regarding the policies through which the problems could be overcome. Furthermore, a model was developed and tested for an effective marketing strategy of LPG in Warri Nigeria. ii / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

This study compared three methods of detecting test item bias, the chi-square approach, the transformed item difficulties approach, and the Linn-Harnish three-parameter item response approach which is the only Item Response Theory (IRT) method that can be utilized with minority samples relatively small in size. The items on two tests which measured writing and reading skills were examined for evidence of sex and ethnic bias. Eight sets of samples, four from each test, were randomly selected from the population (N=7287) of sixth, seventh, and eighth grade students enrolled in a large, urban school district in the southwestern United States. Each set of samples, male/female, White/Hispanic, White/Black, and White/White, contained 800 examinees in the majority group and 200 in the minority group. In an attempt to control differences in ability that may have existed between the various population groups, examinees with scores greater or less than two standard deviations from their group's mean were eliminated. Ethnic samples contained equal numbers of each sex. The White/White sets of samples were utilized to provide baseline bias estimates because the tests could not logically be biased against these groups. Bias indices were then calculated for each set of samples with each of the three methods. Findings of this study indicate that the percent agreement between the Linn-Harnish IRT method and the chisquare and transformed difficulties methods is similar to that found in previous studies comparing the latter approaches with other IRT methods requiring large minority samples. Therefore, it appears that the Linn-Harnish IRT approach can be used in lieu of other more restrictive IRT methods. Ethnic bias appears to exist in the two tests as measured by the large mean bias indices for the White/Hispanic and White/Black samples. Little sex bias was found as evidenced by the low mean bias indices of the male/ female samples and the fact that the male/female mean bias indices were lower than those of the White/White in 33% of the samples.

The purpose of this study was: (1) to evaluate the level of grief experienced by healthcare providers in a pediatric subacute facility, (2) to compare the levels of grief between different groups of healthcare providers (Certified Nurses' Aides, Licensed Nurses, and Respiratory Care Practitioners), and (3) to describe the personality/demographic factors that influence a healthcare provider's ability to cope effectively with compound grief.

his thesis deals with the supply and demand and the impact of advertising on these two microeconomic variables. The work is focused on describing the operation of supply and demand from marketing point of view and not from a microeconomic perspective. In the theoretical part of this work to explain the essence of marketing and advertising, that can well influence the need and demand for goods and services. I'm also concerned with marketing mix and communication mix, which is the theoretical basis for the establishment of marketing activities to promote services and products. The theoretical outline the development of communication campaigns, as each campaign must be properly planned so as to be successful. The aim of this thesis is to examine the functioning of supply and demand, and assess the impact of advertising on supply and demand. This issue in a practical example of the real estate agents Dachi,Ltd., based in Olomouc. Practically make a quantitative marketing research methods and hypotheses are tested using a test of goodness of fit chi-square.

The content of this thesis is the design and statistical tests of two di erent hardware random number generators. It also includes an overview of the sources of entropy, algorithms used to correct deviations from the normal distribution and the description of statistical tests.

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Doctor of Philosophy / Department of Statistics / James W. Neill / Checking the adequacy of a proposed parametric nonlinear regression model is important in order to obtain useful predictions and reliable parameter inferences. Lack of fit is said to exist when the regression function does not adequately describe the mean of the response vector. This dissertation considers asymptotics, implementation and a comparative performance for the likelihood ratio tests suggested by Neill and Miller (2003). These tests use constructed alternative models determined by decomposing the lack of fit space according to clusterings of the observations. Clusterings are selected by a maximum power strategy and a sequence of statistical experiments is developed in the sense of Le Cam. L2 differentiability of the parametric array of probability measures associated with the sequence of experiments is established in this dissertation, leading to local asymptotic normality. Utilizing contiguity, the limit noncentral chi-square distribution under local parameter alternatives is then derived. For implementation purposes, standard linear model projection algorithms are used to approximate the likelihood ratio tests, after using the convexity of a class of fuzzy clusterings to form a smooth alternative model which is necessarily used to approximate the corresponding maximum optimal statistical experiment. It is demonstrated empirically that good power can result by allowing cluster selection to vary according to different points along the expectation surface of the proposed nonlinear regression model. However, in some cases, a single maximum clustering suffices, leading to the development of a Bonferroni adjusted multiple testing procedure. In addition, the maximin clustering based likelihood ratio tests were observed to possess markedly better simulated power than the generalized likelihood ratio test with semiparametric alternative model presented by Ciprian and Ruppert (2004).

Thesis (M. Education) -- Central University of Technology, Free State, 2013 / The purpose of the study was to investigate the relationship between parental support and self-regulated learning behaviour of grade 12 learners. The study investigated support given to self-regulated learning of grade 12 learners. It gathered both quantitative and qualitative data. The researcher adopted the QUAN-qual model, which is also known as explanatory design. In this model quantitative data are collected first and are more heavily weighted than qualitative data. The quantitative method investigated the relationship between parental support and grade 12 learners’ self-regulated learning behaviour. It also investigated how parental support contributed to learner self-regulated learning behaviour. Qualitative research design explained strategies schools used to encourage positive parental support in their children’s self-regulated learning. It also explained why parents did not offer their support to their children’s education despite the fact that the South African School Act of 1996 encouraged them to do so. The population included grade 12 teachers and learners, as well as learners’ parents from different secondary schools in the Lejweleputswa district. The researcher administered questionnaires to 118 teachers and 218 learners, while 6 parents were interviewed. Teachers and learners were handed relevant questionnaires aimed at their level of participation in the survey. For quantitative data analysis the chi-square test was employed to test whether there were relationships between the variables. The study revealed that there was statistical significant relationship between parental support and learners’ self-regulated learning behaviour. Qualitative data was analysed making use of different analytical concepts used to guide researchers in qualitative data analysis. Although learners may acquire effective self-regulated learning strategies on their own, proper guidance from parents and teachers is very crucial, especially in the early stages of learning. The study established that regular general parent’s meetings, each term, help to facilitate improved learner performance. Amongst others, the researcher recommended that schools should introduce incentive for parental involvement in school matters.