Promoting online media relations: Public relations departments’ use of Internet in the UAE

This paper discusses the use of Internet by public relations departments in the United Arab Emirates, to reach their key publics online and to gather information and monitor data to perform their tasks and to promote and develop their relations with the news media. Findings of the study show that all 24 organizations have a homepage, but only two thirds of them are posting their publications on the net, and only one third are using electronic newspapers to monitor their coverage in the media and to gather news, data and information of importance for the various tasks they perform. Only three organizations out of 24 have an online newsroom, and only two have a virtual tour about the organization. None of the surveyed organizations’ Web site has a film or videos. Organizations in the United Arab Emirates still have a lot to do to take advantage fully and rationally of what interactive communication, Internet and online publications are offering for a better performance and more effective public relations.     

Patterns of Spending Behavior and the Relative Position in the Income Distribution: Some Empirical Evidence

A model integrating the permanent income and relative income hypotheses was employed to explain consumer expenditure behavior in the U.S. The model was empirically tested using data from the interview survey portion of the 1996 and 1997 Consumer Expenditure Survey. The results indicate that household expenditure behavior is generally explained by both hypotheses when integrated in one model.     

Annual mortality rates and excess deaths of children under five in Iraq, 1991-98

Data from two parallel household surveys conducted in Iraq by UNICEF in 1999 show that under-5 mortality declined steadily from 1974 to 1990, reaching about 63 per 1,000 live births in the period 1986-90. It then rose dramatically to 118 per 1,000 in 1991, the year of the Gulf War. The number of 'excess' under-5 deaths (i.e., the number in excess of the number predicted from past trends) in Iraq between 1991 and 1998 was calculated assuming that, instead of the rates measured by the 1999 survey for this period, either (a) average mortality rates for the period 1986-90 had been maintained, or (b) mortality had continued to decline at the rate observed between 1974 and 1990. According to these calculations, the estimated number of excess deaths resulting from the Gulf War and its aftermath up to 1998 was between 400,000 (assumption a) and 500,000 (assumption b).     

Bayesian estimation of an AR(1) process with exponential white noise

The object of this paper is a Bayesian analysis of the autoregressive model X _t ?=?ρX _t?1?+?Y _t where 0?Y _t are independent random variables with an exponential distribution of parameter θ. Our study generalizes some results obtained by Turkmann (1990 Amaral Turkmann, M. A. (1990). Bayesian analysis of an autoregressive process with exponential white noise. Statistics, 4: 601–608.  [Google Scholar]). Our analysis is based on a more general non-informative prior which allows us to improve the estimators of ρ and θ.     

Generalized Linear Factor Models: A New Local EM Estimation Algorithm

In this article, a general approach to latent variable models based on an underlying generalized linear model (GLM) with factor analysis observation process is introduced. We call these models Generalized Linear Factor Models (GLFM). The observations are produced from a general model framework that involves observed and latent variables that are assumed to be distributed in the exponential family. More specifically, we concentrate on situations where the observed variables are both discretely measured (e.g., binomial, Poisson) and continuously distributed (e.g., gamma). The common latent factors are assumed to be independent with a standard multivariate normal distribution. Practical details of training such models with a new local expectation-maximization (EM) algorithm, which can be considered as a generalized EM-type algorithm, are also discussed. In conjunction with an approximated version of the Fisher score algorithm (FSA), we show how to calculate maximum likelihood estimates of the model parameters, and to yield inferences about the unobservable path of the common factors. The methodology is illustrated by an extensive Monte Carlo simulation study and the results show promising performance.     

Combined estimating function for random coefficient models with correlated errors

ABSTRACT

Estimating functionshave been shown to be convenient to study inference for non linear time series models. Recently, Thavaneswaran et al. (2012 Thavaneswaran, A., Liang, Y., Frank, J. (2012). Inference for random coefficient volatility models. Stat. Probab. Lett. 82(12):2086–2090.[Crossref], [Web of Science ®] , [Google Scholar]) used combined estimating functions to study inference for random coefficient autoregressive (RCA) models with generalized autoregressive heteroscedasticity errors. While most RCA modeling assumes that the random term and the error are independent, Chandra and Taniguchi (2001 Chandra, S.A., Taniguchi, M. (2001). Estimating functions for nonlinear time series models. Ann. Inst. Stat. Math 53(1):125–141.[Crossref], [Web of Science ®] , [Google Scholar]) studied inference for RCA models with correlated errors using linear estimating functions. In this paper, we derive the quadratic estimating functions for the joint estimation of the conditional mean, variance, and correlation parameters of the RCA models with correlated errors.     

Outlier Detection in a Circular Regression Model Using COVRATIO Statistic

In this article, we model the relationship between two circular variables using the circular regression models, to be called JS circular regression model, which was proposed by Jammalamadaka and Sarma (1993). The model has many interesting properties and is sensitive enough to detect the occurrence of outliers. We focus our attention on the problem of identifying outliers in this model. In particular, we extend the use of the COVRATIO statistic, which has been successfully used in the linear case for the same purpose, to the JS circular regression model via a row deletion approach. Through simulation studies, the cut-off points for the new procedure are obtained and its power of performance is investigated. It is found that the performance improves when the resulting residuals have small variance and when the sample size gets larger. An example of the application of the procedure is presented using a real dataset.     

A New Test of Discordancy in Circular Data

In this article, we present an alternative test of discordancy in samples of univariate circular data. The new technique is based on the effect of existence of an outlier on the summation of circular distances of the point of interest to all other points. The percentage points are calculated and the performance is examined. We compare the performance of the test in detecting an outlier with other tests and show that the new approach performs relatively better than other known tests. As an illustration a practical example is presented.     

A note on estimation and test for the rayleigh amplitude distribution

In an expository paper, Siddiqui (1962), presented and investigated the origin of the Rayleigh Power Distribution.He also discussed the problems of estimation and fitting the distribution to some numerical data. In this article we discuss two problems connected with the Rayleigh Amplitude Distribution (RAD). The first is an extension to the work done by Siddiqui on estimation, where the second is concerned with testing the equality of several Rayleigh Amplitude Distributions, and in this context we derive the asymptotic null distribution of the test criterion.     

Multiple step-stress accelerated life test: the tampered failure rate model

Battacharyya and Soejoeti (1989) proposed the tampered failure rate model for step-stress accelerated life testing. In this note, their model is generalized from the simple (2-step) step-stress setting to the multiple (k-step, k > 2) setting. For the parametric setting where the life distribution under constant stress is Weibull, maximum likelihood estimation is investigated and the situation where the different stress levels are equispaced is looked at.