Showing papers in "Statistica in 2017"
TL;DR: This review is believed to be the first of its kind and an up-to-date and a comprehensive review of known parametric copulas as well as applications and open problems.
Abstract: Copulas are used to specify dependence between two or more random variables. The last few years have seen a surge of developments of parametric models for copulas. Here, we provide an up-to-date and a comprehensive review of known parametric copulas as well as applications and open problems. This review is believed to be the first of its kind.
25 citations
TL;DR: De Finetti's approach to Bayesian statistical inference was translated into English and published in the volume: Bruno De Finetti, Induction and Probability, Biblioteca di Statistica, eds. P. Monari, D. Cocchi, Clueb, Bologna, 1993.
Abstract: This work was translated into English and published in the volume: Bruno De Finetti, Induction and Probability, Biblioteca di Statistica, eds. P. Monari, D. Cocchi, Clueb, Bologna, 1993. Bayesian statistical Inference is one of the last fundamental philosophical papers in which we can find the essential De Finetti's approach to the statistical inference.
23 citations
TL;DR: In this paper, the authors point out that the distribution is a particular case of at least two known distributions and that most of the properties derived by Nedjar and Zeghdoudi are already known.
Abstract: Nedjar and Zeghdoudi (2016) studied various properties of a distribution which they claim to have introduced. Here, we point out that the distribution is a particular case of at least two known distributions. Most of the properties derived by Nedjar and Zeghdoudi are already known. We also point out that most of the results presented by Nedjar and Zeghdoudi are either incorrect or not useful.
16 citations
TL;DR: In this paper, point estimation and testing procedures for different parametric functions under Type II and Type I censoring are developed for different parameter functions under different types of censoring. And a new technique of obtaining these estimators is introduced.
Abstract: Exponentiated distributions are considered. Two measures of reliability are considered, R(t)=P(X>t) and P=P(X>Y). Point estimation and testing procedures are developed for different parametric functions under Type II and Type I censoring. Uniformly minimum variance unbiased estimators (UMVUES) and maximum likelihood estimators (MLES) are derived. A new technique of obtaining these estimators is introduced.
8 citations
TL;DR: The overall aim of this work is to review test equating methods with a particularly detailed description of item response theory (IRT) equating, by describing old and new methods.
Abstract: The overall aim of this work is to review test equating methods with a particularly detailed description of item response theory (IRT) equating. Test score equating is used to compare different test scores from different test forms. Several methods have been developed to conduct equating: traditional methods, kernel method, and IRT equating. We synthetically explain the traditional equating methods which include mean equating, linear equating and equipercentile equating and which have been developed under all the possible data collection designs. We also briefly describe the idea of the kernel method: this is a unified approach to test equating for which recent interesting developments have been proposed. Then we focus on IRT equating, by describing old and new methods: in particular, we define IRT observed-score kernel equating and IRT observed-score equating using covariates, as well as other recent proposals in this field. We conclude the review by describing strengths and weaknesses of the different discussed approaches and by identifying future research topics.
7 citations
TL;DR: In this article, ranked set two-sample permutation test of comparing two independent groups in terms of some measure of location is presented, and the statistical power of these new test statistics are evaluated numerically.
Abstract: In this paper, ranked set two-sample permutation test of comparing two-independent groups in terms of some measure of location is presented. Three test statistics are proposed. The statistical power of these new test statistics are evaluated numerically. The results are compared with the statistical power of the usual two-sample permutation test under simple random sampling and with the classical independent two-sample t -test.
7 citations
TL;DR: In this paper, the authors tried to show how much reduction in the sample size can be achieved without affecting the scientific validity of the study and also the brief summary on the overall effect of reduced sample size on resources (subjects, time, blood and cost).
Abstract: There are clear guidelines and suggestions on the sample size and power calculation from health authorities (HA) for Bio equivalence (BE) studies in Healthy volunteers (HV). The suggested power is at least 80\% and type 1 error is 5\%. In real life situations, the clinical trials plan with more than 80\%, giving rise to larger sample size. The increased power means more subjects, more wastage of time and more resources to complete the study, resulting in more money spent. This paper attempts to show how much reduction in the sample size can be achieved without affecting the scientific validity of the study and also the brief summary on the overall effect of reduced sample size on resources (subjects, time, blood and cost). We executed simulations in order to show the impact on the power and the 2 one sided confidence interval approach to show the study equivalence or otherwise. For illustration purpose, a couple of 2 period cross over studies were considered. 100 simulations were executed with different sample sizes to compare with the original results.
6 citations
TL;DR: Based on the Renyi entropy and its divergence, the authors proposed a generalized measure of inaccuracy of order α(≠1)>0 between two residual and past lifetime distributions of a system.
Abstract: Generalized information measures play an important role in the measurement of uncertainty of certain random variables, where the standard practice of applying ordinary uncertainty measures fails to fit. Based on the Renyi entropy and its divergence, we propose a generalized measure of inaccuracy of order α(≠1)>0 between two residual and past lifetime distributions of a system. We study some important properties and characterizations of these measures. A numerical example is given to illustrate the usefulness of the proposed measure.
6 citations
TL;DR: In this paper, a new extended generalized Lindley distribution (NEGLD$) was proposed and some statistical properties of the proposed distribution are explicitly derived, such as conditional moments, vitality functions, geometric vitality function, mean inactivity time and various entropy measures.
Abstract: In this paper, we introduce a new extended generalized Lindley distribution ($NEGLD$). Some statistical properties of the proposed distribution are explicitly derived. These include conditional moments, vitality function, geometric vitality function, mean inactivity time and various entropy measures. Maximum likelihood estimation, moment estimation and asymptotic confidence interval are used for estimating the parameters. The distribution has been fitted to a data set to test its goodness of fit and it has been found that this distribution gives better fit than the some other well-known existing distributions.
5 citations
TL;DR: The experimental strategy developed thanks to the DOE methodology enhance innovation capability in the field of thermoforming production processes for active packaging by use of optimal designs, and in the meantime a full exploration of factorial space.
Abstract: The experimental strategy developed thanks to the DOE methodology enhance innovation capability in the field of thermoforming production processes for active packaging. It is composed of three phases: i) material characterization, ii) production in pilot line, and iii) performance of final product. It allows selection of material, and correlation between control factors in production and performances of final product. Use of optimal designs allows reduction of number of tests, and in the meantime a full exploration of factorial space.
4 citations
TL;DR: In this paper, the authors consider a symmetric stable process with a spectral representation with an additive constant error and study the rate of convergence when the spectral density has some behaviors at origin.
Abstract: Consider a symmetric α stable process having a spectral representation with an additive constant error. An estimator of that error and its rate of convergence are given. We study the rate of convergence when the spectral density have some behaviors at origin. Few long memory processes are taken here as example.
TL;DR: In this article, the authors developed tools for computing the Pitman efficiency exactly, based on some recent developments due to the authors and some calculus of variations, and their use is illustrated numerically.
Abstract: Pitman efficiency is the oldest known efficiency. Most of the known results for computing the Pitman efficiency take the form of bounds. Based on some recent developments due to the authors and some calculus of variations, we develop tools for computing the Pitman efficiency exactly. Their use is illustrated numerically.
TL;DR: In this article, a simpler expression is derived for the UMVUE of $\theta$ and a comprehensive investigation is provided for comparing the sequential estimators based on the maximum likelihood estimator (MLE) and the Uniformly Minimum Variance Unbiased Estimator (UMVUE).
Abstract: Mukhopadhyay and Cicconetti \cite{mc2004} derived the Maximum Likelihood Estimator (MLE) and the Uniformly Minimum Variance Unbiased Estimator (UMVUE) of $\theta$ in $N (\theta, \theta)$ and discussed their application to purely sequential and two-stage bounded risk estimation of $\theta$. In this paper, a much simpler expression is derived for the UMVUE of $\theta$. Using this expression, a comprehensive investigation is provided for comparing the performances of the sequential estimators based on the MLE and the UMVUE.