The central limit theorem ensures that a sum of random variables tends to a Gaussian distribution as their total number tends to infinity. However, for a class of positive random variables, we find that the sum tends faster to a log-normal distribution. Although the sum tends eventually to a Gaussian distribution, the distribution of the sum is always close to a log-normal distribution rather t...

reconnaissance drought index (rdi) is based on fitting a log-normal distribution to the ratio of precipitation to evapotranspiration (eto) values in selected periods. in this index value of eto were calculated based on mean temperature by thorenth-waite (th) method. th method, may underestimated eto values comparing to the actual in arid and semi arid regions. the log-normal distribution may no...

The aim of this work is provide some insight into the response time statistics of enterprise resource planning systems. We propose a simple mean-field model for the response-time distribution in such systems. This model yields a log-normal distribution of response times. We present data from performance measurements to support the result. The data show that the response-time distribution of a g...

The statistical analysis of positron emission tomography (PET) standardized uptake value (SUV) measurements is challenging due to the skewed nature of SUV distributions. This limits utilization of powerful parametric statistical models for analyzing SUV measurements. An ad-hoc approach, which is frequently used in practice, is to blindly use a log transformation, which may or may not result in ...

Sums of lognormal random variables (RVs) occur in many important problems in wireless communications especially in interferences calculation. Several methods have been proposed to approximate the lognormal sum distribution. Most of them requires lengthy Monte Carlo simulations, or advanced slowly converging numerical integrations for curve fitting and parameters estimation. Recently, it has bee...

In wireless body-centric communications, either the transmitter or the receiver, or both are located in close proximity to the human body. Thus, the Line-of-Sight (LOS) components of the radio signal are particularly susceptible to shadowing caused by human body. In earlier, the effect of human body shadowing was studied using κ-μ fading channel, where the resultant dominant signal components d...

It is typically difficult to estimate the number of degrees freedom due leptokurtic nature Student t-distribution. Particularly in studies with small sample sizes, special care needed concerning prior choice order ensure that analysis not overly dominated by any distribution. In this article, popular priors used existing literature are examined characterizing their distributional properties on ...