Problem: To simplify the computation of the variance in before-after studies, it is generally assumed that the observed crash data for each entity (or observation) are Poisson distributed. Given the characteristics of this distribution, the observed value ( i x ) for each entity is implicitly made equal to its variance. However, the variance should be estimated using the conditional properties ...

The Poisson distribution has been widely used for modelling rater agreement using loglinear models. Mostly in all life or social science researches, subjects are being classified into categories by rater, interviewers or observers and most of these tables indicate that the cell counts are mixtures of either too big values and two small values or zeroes which are sparse data. We refer to sparse ...

Within the family of zero-inflated Poisson distributions, the data has Poisson distribution if any only if the mean equals the variance. In this paper we compare two closely related test statistics constructed based on this idea. Our results show that although these two tests are asymptotically equivalent under the null hypothesis and are equally efficient, one test is always more efficient tha...

Poisson noise removal is of significant importance for many applications such as spectral imaging, night vision and especially in medical imaging and astronomy. Gaussian scale mixture based methods have been widely used in image denoising. In this paper, we focus on the Poisson noise and propose a new strategy based on Bayesian least squares method for its removal. We begin with a method that r...

Diffusion methods were used to investigate the fixation probability, average time until fixation and extinction, and cumulative heterozygosity and genetic variance for single mutant genes in finite populations with partial inbreeding. The critical parameters in the approximation are the coefficient of inbreeding due to nonrandom mating (F) and the effective population size (Ne), which also depe...

In the scope of the Fermi mission, Poisson noise removal should improve data quality and make source detection easier. This paper presents a method for Poisson data denoising on sphere, called Multi-Scale Variance Stabilizing Transform on Sphere (MS-VSTS). This method is based on a Variance Stabilizing Transform (VST), a transform which aims to stabilize a Poisson data set such that each stabil...

Reading the paper by Zweig and Csank (1978) prompted me to write the following note. The authors have attempted to adjust a Poisson distribution to the daily mortality at six Montreal hospitals. They, in fact, succeeded in their attempt as far as large hospitals are concerned. Therefore, Zweig and Csank concluded that the daily deaths 'may be said to occur at random and independently . . .'. Ho...