Browsing İstatistik Bölümü Makale Koleksiyonu by Subject "Mathematics"
Now showing items 1-20 of 25
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A Comparative Study on Optimization Methods For The Constrained Nonlinear Programming Problems
(Hindawi Publishing Corporation, 2005) -
A New Class of Unbiased Linear Estimators in Systematic Sampling
(Hacettepe Univ, Fac Sci, 2017)Use of auxiliary variables is very common in estimating various population parameters. In this study, we suggest a class of unbiased linear estimators for estimating the population mean of the study variate y using information ... -
A New Improved Estimator of Population Mean in Partial Additive Randomized Response Models
(Hacettepe Univ, Fac Sci, 2017)In this study, we have developed a new improved estimator for the population mean estimation of the sensitive study variable in Partial Additive Randomized Response Models (RRMs) using two non-sensitive auxiliary variables. ... -
A New Proposed Model of Restricted Data Envelopment Analysis By Correlation Coefficients
(Elsevier Science Inc, 2013)The concept of efficiency in data envelopment analysis (DEA) is defined as weighted sum of outputs/weighted sum of inputs. In order to calculate the maximum efficiency score, each decision making unit (DMU)'s inputs and ... -
Almost Unbiased Estimation Procedures Of Population Mean In Two-Occasion Successive Sampling
(Hacettepe Univ, Fac Sci, 2018)The objective of this paper is to construct some unbiased estimators of the current population mean in two-occasion successive sampling. Utilizing the readily available information on an auxiliary variable on both occasions, ... -
An Arma Type Fuzzy Time Series Forecasting Method Based On Particle Swarm Optimization
(Hindawi Ltd, 2013)In the literature, fuzzy time series forecasting models generally include fuzzy lagged variables. Thus, these fuzzy time series models have only autoregressive structure. Using such fuzzy time series models can cause ... -
Autocorrelation Corrected Standard Error For Two Sample T-Test Under Serial Dependence
(Hacettepe Univ, Fac Sci, 2017)The classical two-sample t-test assumes that observations are independent. A violation of this assumption could lead to inaccurate results and incorrectly analyzing data leads to erroneous statistical inferences. However, ... -
Bayesian Estimation of Order-Restricted and Unrestricted Association Models
(Elsevier Inc, 2013)Association models include score parameters to multiplicatively represent the hierarchy between the levels of the considered ordinal factor. If order restrictions are placed on the scores, an estimation problem becomes a ... -
Forecasting Nonlinear Time Series With A Hybrid Methodology
(Pergamon-Elsevier Science Ltd, 2009)In recent years, artificial neural networks (ANNs) have been used for forecasting in time series in the literature. Although it is possible to model both linear and nonlinear structures in time series by using ANNs, they ... -
Hartley-Ross Type Unbiased Estimators Using The Stratified Random Sampling
(Hacettepe Univ, Fac Sci, 2017)This study mentions Hartley-Ross type unbiased ratio estimators of the finite population mean in the stratified random sampling using the auxiliary variable. We propose the unbiased estimators using the estimators in Kadilar ... -
Improvement In Estimating The Population Mean In Simple Random Sampling
(Pergamon-Elsevier Science Ltd, 2006)This paper proposes some estimators for the population mean using the ratio estimators presented in [C. Kadilar, H. Cingi, Ratio estimators in simple random sampling, Applied Mathematics and Computation 151 (2004) 893-902] ... -
Improving Weighted Information Criterion By Using Optimization
(Elsevier Science Bv, 2010)Although artificial neural networks (ANN) have been widely used in forecasting time series, the determination of the best model is still a problem that has been studied a lot. Various approaches available in the literature ... -
Joint Prior Distributions for Variance Parameters in Bayesian Analysis of Normal Hierarchical Models
(Elsevier Inc, 2015)In random effect models, error variance (stage 1 variance) and scalar random effect variance components (stage 2 variances) are a priori modeled independently. Considering the intrinsic link between the stages 1 and 2 ... -
Modified Estimators For The Change Point In Hazard Function
(Elsevier Science Bv, 2009)We propose the consistent estimators for the change point in hazard function by improving the estimators in [A.P. Basu, J.K. Ghosh, S.N. Joshi, On estimating change point in a failure rate, in: S.S. Gupta,J.O. Berger (Eds.), ... -
Modified Welch Test Statistic For Anova Under Weibull Distribution
(Hacettepe Univ, Fac Sci, 2016)A modification to Welch test statistic is proposed to test the equality of population means of various groups under a Weibull distribution. The proposed test statistic is simple and corresponds to the standard Welch test ... -
Odd Burr Lindley Distribution With Properties And Applications
(Hacettepe Univ, Fac Sci, 2017)In this study, we introduce a new model called the Odd Burr Lindley distribution which extends the Lindley distribution and has increasing, bathtub and upside down shapes for the hazard rate function. It includes the odd ... -
On The Use Of Imputation Methods For Missing Data In Estimation Of Population Mean Under Two-Phase Sampling Design
(Hacettepe Univ, Fac Sci, 2018)Non-response is an unavoidable feature in sample surveys and it needs to be carefully handled to avoid the biased estimates of population characteristics/parameters. Imputation is one of the latest fascinating methods which ... -
Robust Model Selection Criteria For Robust S And Lts Estimators
(Hacettepe Univ, Fac Sci, 2016)Outliers and multi-collinearity often have large influence in the model/variable selection process in linear regression analysis. To investigate this combined problem of multi-collinearity and outliers, we studied and ... -
Solving Large Scale Systems Of Linear Equations With A Stabilized Lanczos-Type Algorithms Running On A Cloud Computing Platform
(Hacettepe Univ, Fac Sci, 2018)The Lanczos-type algorithms for Systems of Linear Equations (SLEs) are efficient but fragile. A number of ways to resolve this issue have been suggested. But, the problem is still not fully sorted, in our view. Here, we ... -
Some Imputation Methods For Missing Data In Sample Surveys
(Hacettepe Univ, Fac Sci, 2016)The present work suggests some imputation methods to deal with the problems of non-response in sample surveys. The imputation methods presented in this work lead to the precise estimation strategies of population mean. ...