Thesis (Ph. D.)--Virginia Polytechnic Institute, 1955. / Vita. Abstract. Includes bibliographical references (leaves 114-119). Also available via the Internet.

Thesis (Ph. D.)--University of Hong Kong, 1993.

No description available.

Residential real estate forecasting has become a part of the larger process of business planning and strategic management. Several studies of housing price trends recommend confining statistical analysis to repeated sales of residential property. This study presents an alternate methodology which combines information only on repeated residential sales regardless of the changes that has been made in the house in-between the sales. Additive and multiplicative models were used to forecast the residential property prices in Nelson Mandela Metropole. Data was collected from various sources and was reconciled into one data set for analysis through a process of data screening.

The method of paired comparisons is seen as a technique used to rank a set of objects with respect to an abstract or immeasurable property. To do this, the objects get to be compared two at a time. The results are input into a model, resulting in numbers known as weights being assigned to the objects. The weights are then used to rank the objects. The method of paired comparisons was first used for psychometric investigations. Various other applications of the method are also present, for example economic applications, and applications in sports statistics. This study involves taking paired comparison models and making them time-dependent. Not much research has been done in this area. Three new time series models for paired comparisons are created. Simulations are done to support the evidence obtained, and theoretical as well as practical examples are given to illustrate the results and to verify the efficiency of the new models. A literature study is given on the method of paired comparisons, as well as on the areas in which we apply our models. Our first two time series models for paired comparisons are the Linear-Trend Bradley- Terry Model and the Sinusoidal Bradley-Terry Model. We use the maximum likelihood approach to solve these models. We test our models using exact and randomly simulated data for various time periods and various numbers of objects. We adapt the Linear-Trend Bradley-Terry Model and received our third time series model for paired comparisons, the Log Linear-Trend Bradley-Terry Model. The daily maximum and minimum temperatures were received for Port Elizabeth, Uitenhage and Coega for 2005 until 2009. To evaluate the performance of the Linear-Trend Bradley-Terry Model and the Sinusoidal Bradley-Terry Model on estimating missing temperature data, we artificially remove observations of temperature from Coega’s temperature dataset for 2006 until 2008, and use various forms of these models to estimate the missing data points. The exchange rates for 2005 until 2008 between the following currencies: the Rand, Dollar, Euro, Pound and Yen, were obtained and various forms of our Log Linear-Trend Bradley-Terry Model are used to forecast the exchange rate for one day ahead for each month in 2006 until 2008. One of the features of this study is that we apply our time series models for paired comparisons to areas which comprise non-standard paired comparisons; and we want to encourage the use of the method of paired comparisons in a broader sense than what it is traditionally used for. The results of this study can be used in various other areas, like for example, in sports statistics, to rank the strength of sports players and predict their future scores; in Physics, to calculate weather risks of electricity generation, particularly risks related to nuclear power plants, and so forth, as well as in many other areas. It is hoped that this research will open the door to much more research in combining time series analysis with the method of paired comparisons.

In this thesis, we focus on the the comparison of treatments with ordered categorical responses. The three cases of treatment comparisons will all be studied. The main objective of this thesis is to develop more effective comparison methods for treatments with ordinal responses and to address some important issues involved in different comparison problems. Our major statistical approach is to consider ordinal responses as manifestations of some underlying continuous random variables. / The comparison of treatments to detect possible treatment effects is a very important topic in statistical research. It has been drawing significant interests from both academicians and practitioners. Important research work on treatment comparisons dates back several decades. For treatment comparisons, the following three cases are very common: the comparison of two independent treatments; the comparison of treatments with repeated measurements; and the multiple comparison of several treatments. For different cases, the involved research issues are usually different. In many fields of study, the level of measurement for responses of the treatments is ordinal. Many examples can be found in areas such as biostatistics, psychology, sociology, and market research, where the ordered categorical variables play an important role. / This thesis consists of three main parts. In the first part, we consider the modeling of treatments with longitudinal ordinal responses by a latent growth curve. On the basis of such a latent growth curve, we achieve a comprehensive flexible model with straightforward interpretations and a variety of applications including treatment comparison, the analysis of covariates, and equivalence test of treatments. In the second part, we consider the comparison of several treatments with a control for ordinal responses. By considering the ordinal responses as manifestations of some underlying normal random variables, a latent normal distribution model is utilized and the corresponding parameter estimation method is proposed. Further, we also derive testing procedures that compare several treatments with a control under an analytical framework. Both single-step and stepwise procedures are introduced, and these procedures are compared in terms of average power based on a simulation study. In the last part of this thesis, we establish a unified framework for treatment comparisons with ordinal responses, which allows various treatment comparison methods be comprehended using a unified perspective. The latent variable model is also utilized, but the underlying random variables are allowed to have any member of the location-scale distribution family. This latent variable model under such a specification of underlying distributions subsumes many existing models in the literature. A two-step procedure to identify the model and produce the parameter estimates is proposed. Based on this procedure, many important statistical inferences can be conveniently conducted. Furthermore, the sample size determination method based on the latent variable method is also proposed. The proposed latent variable method is compared with the existing methods in terms of power and sample size. / Lu, Tongyu. / Adviser: Wai-Yin Poon. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 94-101). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

No description available.

In order to clarify the taxonomic problems which exist among the group azotobacter by serological method, 24 cultures of Azotobacter including 9 species were tested as antigens in Ouchterlony plates against 3 different antisera obtained from rabbits immunized with A. chroococcum ACl6, A. macrocytogenes St.M. and A. vinelandii 12837, respectively. The results showed more cross reactivity in intraspecies reactions than in interspecies ones and indicated the presence of a common immunogenic determinant. This work presents the results which suggest the effecient classification of Azotobacter by Ouchterlony comparisons of corresponding antigens in different species.

Previous work on two-treatment comparisons has shown that the use of optimal response-adaptive randomisation with group sequential analysis can allocate more patients to the better-performing treatment while preserving the overall type I error rate. The sequence of test statistics for this adaptive design asymptotically satisfi es the canonical joint distribution. The overall type I error rate can be controlled by utilising the error-spending approach. However, previous work focused on immediate responses. The application of the adaptive design to censored survival responses is investigated and different optimal response-adaptive randomised procedures compared. For a maximum duration trial, the information level at the fi nal look is usually unpredictable. An approximate information time is defi ned. Several treatments are often compared in a clinical trial nowadays. The adaptive design generalised to multi-arm clinical trials is studied. First, a global test is considered. The joint distribution of the sequence of test statistics no longer has the canonical distribution. However, the joint distribution can be derived, since the test statistic is a quadratic form of independent normal variables. Existing critical boundaries are based on normal responses and known variances with equal allocation and equal increments in information. Our results show that these boundaries can be used approximately for designs with other types of responses, unequal variances or unbalanced allocation. If the global null hypothesis is rejected, then pairwise comparisons are conducted at the current and subsequent looks to investigate which treatment effects differ. This is an analogue of Fisher's least signi cant difference method that can control the family-wise error rate. The adaptive design can target any optimal allocation to achieve some optimality criterion, and allows dropping of inferior treatments at interim looks, which can be unequally spaced in information time. Optimal allocation proportions after dropping arms are described. The power is not adversely affected by unbalanced allocation.

Cheung Ching Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 64-65). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Multiple Comparison Procedures --- p.1 / Chapter 1.2 --- Multiple Comparisons with a control --- p.2 / Chapter 1.3 --- Multiple Comparisons with a control in two-way designs --- p.5 / Chapter 1.4 --- Example --- p.12 / Chapter 1.5 --- Thesis Objectives --- p.13 / Chapter 2 --- Evaluation of Power (Homogeneous Variance) --- p.14 / Chapter 2.1 --- Definition and the use of power --- p.14 / Chapter 2.2 --- Setup and Notations --- p.15 / Chapter 2.3 --- Evaluation of power --- p.16 / Chapter 2.4 --- Computational Details --- p.19 / Chapter 2.4.1 --- Algorithm --- p.19 / Chapter 2.4.2 --- Results --- p.20 / Chapter 2.5 --- Numerical Example --- p.39 / Chapter 3 --- Evaluation of Power (Heterogeneous Variances) --- p.42 / Chapter 3.1 --- Setup and Notations --- p.42 / Chapter 3.2 --- Evaluation of power --- p.43 / Chapter 3.3 --- Results --- p.45 / Chapter 3.3.1 --- All-pairs Power --- p.46 / Chapter 3.3.2 --- Any-pair Power --- p.53 / Chapter 3.4 --- Numerical Example --- p.60 / Chapter 4 --- Conclusions --- p.63 / References --- p.64