Browsing School of Pure and Applied Sciences by Author "Orwa, George Otieno"
Now showing items 1-16 of 16
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Bias Reduction Technique for Estimating Finite Population Distribution Function under Simple Random Sampling without Replacement.
Onsongo, Winnie Mokeira; Otieno, Romanus Odhiambo; Orwa, George Otieno (International Journal of Statistics and Applications, 2018)The problem of nonparametric estimation of finite population distribution function using multiplicative bias correction technique is considered in this paper. A robust estimator of the finite population distribution function ... -
A bootstrap variance estimation under stratification with few units per stratum.
Habineza, Alexis; Otieno, Romanus Odhiambo; Orwa, George Otieno; Makumi, Nicholas (Journal of Statistics Applications & Probability Letters, 2022)The measurement errors exist and sample survey results are always uncertain because only a portion of the population is measured. Larger samples and superior measurement tools can help to reduce this uncertainty. The ... -
Comparing Edgeworth Expansion and Saddlepoint Approximation in Assessing the Asymptotic Normality Behavior of A Non-Parametric Estimator for Finite Population Total
Okungu, Jacob Oketch; Orwa, George Otieno; Otieno, Romanus Odhiambo (EJ-MATH, European Journal of Mathematics and Statistics, 2023-01)Abstract — Sample surveys concern themselves with drawing inferences about the population based on sample statistics. We assess the asymptotic normality behavior of a proposed nonparametric estimator for finite a population ... -
Comparison of the ratio estimate to the local linear polynomial estimate of finite population totals
Maua, Muga Zablon; Orwa, George Otieno; Otieno, Romanus Odhiambo; Odiwuor, Leo (International Journals of Multidisciplinary Research Academy, 2013)In this paper, attempt to study effects of extreme observations on two estimators of finite population total theoretically and by simulation is made. We compare the ratio estimate with the local linear polynomial estimate ... -
Coverage properties of a neural network estimator of finite population total in high-dimensional space.
Were, Festus A.; Orwa, George Otieno; Otieno, Romanus Odhiambo; Makumi, Nicholas; Aldallal, Ramy (Journal of Mathematics, 2022)The problem in nonparametric estimation of finite population total particularly when dealing with high-dimensional datasets is addressed in this paper. The coverage properties of a robust finite population total estimator ... -
Deriving Penalized Splines For Estimation Of Time Varying Effects In Survival Data
Orwa, Albert Otieno; Orwa, George Otieno; Otieno, Romanus Odhiambo (International Journal of Scientific & Technology Research, 2014)The major interests of survival analysis are either to compare the failure time distribution function or to assess the effects of covariate on survival via appropriate hazards regression models. Cox’s proportional hazards ... -
Effects of outliers on Estimation of Finite Population Totals
Maua, Muga Zablon; Orwa, George Otieno; Otieno, Romanus Odhiambo; Odiwuo, Leo (International Journals of Multidisciplinary Research Academy, 2013)In this paper, attempt to study effects of outliers on two estimators of finite population total theoretically and by simulation is made. We compare the ratio estimate with the local linear polynomial estimate of finite ... -
GENERALISED MODEL BASED CONFIDENCE INTERVALS IN TWO STAGE CLUSTER SAMPLING
Onyango, Christopher Ouma; Otieno, Romanus Odhiambo; Orwa, George Otieno (Pakistan Journal of Statistics and Operation Research, 2010)Chambers and Dorfman (2002) constructed bootstrap confidence intervals in model based estimation for finite population totals assuming that auxiliary values are available throughout a target population and that the auxiliary ... -
Inference on poverty indicators for Ghana
Jakperik, Dioggban; Otieno, Romanus Odhiambo; Orwa, George Otieno (2018-09-14)Poverty indicators are the fundamental statistics used to optimally determine the standards of living of people in any country. These are used for policy planing and analysis. Poverty indicators were estimated using ... -
Nonparametric estimation of distribution function for stratified populations
Onsongo, Winnie Mokeira; Otieno, Romanus Odhiambo; Orwa, George Otieno (International Journal of Probability and Statistics, 2018)Nonparametric estimation of population parameters for finite populations has been used with great success for data that fit the independent and identically distributed framework. However, most of these approaches do not ... -
Nonparametric mixed ratio estimator for a finite population total in stratified sampling
Orwa, George Otieno; Otieno, Romanus Odhiambo; Mwita, Peter Nyamuhanga (Pakistan Journal of Statistics and Operation Research, 2010)We propose a nonparametric regression approach to the estimation of a finite population total in model based frameworks in the case of stratified sampling. Similar work has been done, by Nadaraya and Watson (1964), Hansen ... -
On quantiles estimation based on stratified sampling using multiplicative bias correction approach.
Makumi, Nicholas; Otieno, Romanus Odhiambo; Orwa, George Otieno; Habineza, Alexis (Journal of Mathematics, 2022)In the context of stratified sampling, we develop a nonparametric regression technique to estimating finite population quantiles in model-based frameworks using a multiplicative bias correction strategy. Furthermore, the ... -
Robust Estimation of Finite Population Totals Using a Model Based Approach in the Presence of Two Auxiliary Variables
Mulwa, Damaris Felistus; Orwa, George Otieno; Otieno, Romanus Odhiambo (International Journal of Data Science and Analysis, 2018)The utilization of auxiliary information during surveys increases the accuracy of estimators, thereby giving more reliable estimates of the population parameters of interest. It has been established that the presence of ... -
A SEMI-PARAMETRIC MULTIPLICATIVE BIAS REDUCTION DENSITY WITH A PARAMETRIC START
Jakperik, Dioggban; Otieno, Romanus Odhiambo; Orwa, George Otieno (Pushpa Publishing House, 2018)In this study, a multiplicative semiparametric fourth order bias reduction density is proposed. The proposed density accommodates all parametric distributions and produces optimum results even in situations where the ... -
Variance Estimation for Poverty Indicators via Linearization Technique
Jakperik, Dioggban; Otieno, Romanus Odhiambo; Orwa, George Otieno (2018-08-24)In this study, an assessment of precision of poverty indicators is made with a view to improving its performance. A multiplicative bias reduction density function is used in estimating the poverty indicators and compared ... -
Variance Estimation in Stratified Random Sampling in the Presence of Two Auxiliary Random Variables
Sidelel, Esubalew Belay; Orwa, George Otieno; Otieno, Romanus Odhiambo (International Journal of Science and Research, 2014)The objective of this paper is to develop an improved population variance estimators in the presence of two auxiliary variables in stratified random sampling adapting the family of estimators proposed by Koyunchu and ...