Statistics Research Papers/Topics

ROBUST ADAPTIVE SCHEME FOR GAUSS MARKOV MODEL

The Hogg’s adaptive scheme is extended to the Gauss Markov Model. The Gauss Markov model is a statistical procedure which belongs to the class of general linear model. Gauss Markov model is very sensitive to nonnormality, variance heterogeneity as well as large sample size. These assumptions may be violated as a result of departures from normality and small sample size. To overcome these problems, an Adaptive Scheme is adopted. The Adaptive Scheme is a two step procedure in which a selector...

MULTILEVEL MODELLING WITH APPLICATION TO CHILD DISCIPLINE PRACTICES IN GHANAIAN HOMES

This study applied multilevel modelling to analyze data on child discipline practices from 8,156 households from the MICS 4 data collected by GSS in 2011. The analysis took into consideration intra-cluster correlation that results from the collection of such hierarchical structured data and unmeasured higher level characteristics that impact on values of the response variables. A key purpose of the study was to address the error terms of individual observations that correlate in such datasets...

MODIFICATIONS OF THE WEIGHTED WEIBULL DISTRIBUTION

In modeling real-life events with respect to probability theory, two particular characteristics are considered, either the probability distribution is Flexible or the distribution is Tractable. Statistically, in order to retain the originality of the data, appropriate probability distribution needs to be employed rather than to transform the existing dataset. Classical distributions lack the ability to model and describe some important real-life events. Hence, the derived compound distributio...

CLASSICAL AND BAYESIAN SWITCHING VOLATILITY MODELS FOR ANALYSING STOCK RETURNS IN GHANA

The focus of this study was to model and forecast stock returns of Ghana Commercial Bank on the Ghana Stock Exchange using classical and Bayesian switching volatility models. Due to the presence of stylised facts in stock returns, this study finds it imperative to identify an appropriate risk model that best describes these features. The data utilised in this study are the stock prices of Ghana Commercial Bank transformed into monthly averages of daily closing prices covering 138 months. The ...

TOPP-LEONE ZUBAIR GENERATED FAMILY OF DISTRIBUTIONS WITH APPLICATIONS TO LIFETIME DATA

The Topp-Leone Zubair family of distribution was developed in this study to model life time data. This family of distributions is an improvement of the Topp-Leone and the Zubair families which lacked scale parameter and shape parameters respectively. The statistical properties of the generator were obtained , thus; mixture representation, moments, moment generating function, incomplete moments, inequality measures, mean deviation, median deviation, mean residual life, stochastic ordering, Str...

CHEN FAMILY OF DISTRIBUTIONS WITH APPLICATIONS TO LIFETIME DATA

Classical distributions are at times unable to provide a reasonable fit to certain forms of datasets, hence the need to generalize existing distributions to enhance their flexibility in the modeling of data. In recent times, much attention is focused on developing of new families of distributions for generalizing existing models. This is evident in the vast literature on modification and generalization of statistical distributions carried out by researchers. This study therefore developed gen...

BAYESIAN CONTINUOUS-TIME SURVIVAL ANALYSIS FOR RECOVERY OF TUBERCULOSIS PATIENTS IN BULUK

Tuberculosis is an infectious bacterial disease caused by the bacilli Mycobacterium tuberculosis. The study modeled the prognostic factors for TB patients in Buluk using Kaplan-Meier, Bayesian Continuous-time Survival models, log-logistic and logistic regression models. Age, treatment time, and smear results were found to be associated with treatment outcomes. Pulmonary positive TB was identified to be the most prevalent disease category. The study unveiled that the median recovery time for p...

NEW LIFETIME STATISTICAL DISTRIBUTIONS FOR SYSTEMS CONNECTED IN SERIES

In probability distribution theory, substantial efforts have been made in developing probability distributions for modelling lifetime from systems connected in series. However, there are several significant situations where empirical data set from such systems do not follow any of these existing distributions. Hence, it is essential to generate more flexible distributions for modelling lifetime data from series connected components. In this study, the Nadarajah Haghighi generalised power Weib...

MODELLING DOMESTIC TOURISM DEMAND FOR GHANA

Domestic tourism plays a significant role in Ghana‟s economy as it generates markets for a wide variety of tourism products but lags behind other countries like United Kingdom, Germany, Kenya and other countries in terms of domestic tourism expenditure. Furthermore, no expenditure was known about the general value of domestic tourism at both macro and micro levels. Being motivated by this necessity, the study had to investigate Ghana‟s domestic tourism demand for tourism products from 201...

SOME CONTRIBUTIONS TO ODD FAMILY OF DISTRIBUTIONS WITH APPLICATIONS TO CANCER DATASETS

A new family of distributions, by name generalized odd inverse exponential distribution was developed in this study. The new family of distributions were developed using the concepts of relative odds. The statistical properties such as quantile function, characteristic function, moments, moment generating function, mean residual life, inequality measures and order statistics for the new family of distributions were obtained. The maximum likelihood, ordinary least squares and Cramér-von Mises...

MODELLING AND FORECASTING MATERNAL MORTALITY AND LIVE BIRTHS – USING VARX MODELS: CASE STUDY OF THE UPPER WEST REGIONAL HOSPITAL

The Wa Regional Hospital’s live births and maternal mortality were analysed and forecasted in this study. The data were obtained from the Regional Hospital and covered the period from January 2009 to June 2020. This study applied Vector Autoregressive with exogenous variable to model the interdependent and dynamic structure that exists between the endogenous variables (live births and maternal mortality) and the exogenous variable (maternal age). Also, the dynamic structure of the observed ...

MODERN AGRICULTURAL PRACTICES AND TECHNOLOGIES ON MAIZE PRODUCTION: ASSESSING CLIMATE CHANGE IN THE LAWRA MUNICIPALITY OF THE UPPER WEST REGION OF GHANA

The main aim of the study was to examine the influence of modern agricultural practices and technologies on maize production. Data on yields for five different farming seasons and other attributes of Climate Smart Agriculture Technologies were obtained from three communities in the Lawra Municipality. The study identified a six factor solution which explained the correlation in the observed data without substantial loss of information. Multinomial Logistic Regression and Mixed Effect Linear R...

TRANSMUTED TYPE I GENERAL EXPONENTIAL FAMILY OF DISTRIBUTIONS

The Transmuted Type I General Exponential family of distributions as a new generator is proposed and studied. The new generator has a closed form and therefore very tractable, its hazard rate function has the flexibility to model different kinds of the bathtub shapes. Also, a comprehensive description of the statistical properties of the new generator including explicit expressions for the ordinary and incomplete moments, moments generating function, order statistics and stochastic ordering p...

TWEEDIE REGRESSION ANALYSIS OF DETERMINANTS OF BIRTH WEIGHT IN NAVRONGO

This study models infant birth weight and investigate maternal predictors using lifetime data by taking into account the non-zero probability of zero occurrences of the response variable. The birth weights were found to be positively skewed and leptokurtic in nature. The average birth weight was found to be 2.9898kg. In modelling the determinants of infant birth weight, the Tweedie regression model was compared with Gaussian, Gamma and inverse Gaussian regression models. The performance of th...

MARKOV REGIME-SWITCHING AUTOREGRESSIVE MODEL FOR MODELING RAINFALL IN THE UPPER EAST REGION OF GHANA

The economy of Ghana largely depends on agriculture for its growth. In Ghana, agricultural productivity largely relies on rainfall. This study seeks to explore the rainfall pattern using data from the Ghana Meteorological Agency from January 1999 to December 2019 for the Navrongo and Bolgatanga weather substations. A univariate two-state Markov switching autoregressive model was used to characterize the distinct seasonal regime behavior of the rainfall in the study area. The data sets were fo...


1 - 15 Of 198 Results