Many heterogeneous media and environmental processes are statistically anisotropic, that is, their moments have directional dependence. The term range anisotropy denotes processes that have variograms characterized by direction-dependent correlation lengths and directionally independent sill. We distinguish between two classes of anisotropic covariance models: Class (A) models are reducible to ...

Some observations are more variable in space and relatively less variable in time or vice versa. Based on the major source of variability, regionalized variable theory is used to construct either spatial or temporal semivariograms. Examples include georeferenced soil data, with primarily spatial variability, and daily weather data, with primarily temporal variability, as input to dynamic simula...

Since lifetimes are almost always non-negative, the normal model/distribution may not be appropriate. An easy to use, positive distribution is the exponential distribution. To a less extend, exponential distributions to the survival analysis is like normal distributions to the linear model/ANOVA. Piecewise exponential distribution is also used to bridge/connect the parametric and nonparametric ...

in this paper, some meteorological data, such as temperature, pressure and dew point temperature are used for extracting the atmospheric refractivity in different locations of iran. these data have been measured at different heights in twelve radiosonde sites of country by using meteorological balloons. the set of refractivity points obtained from data of each site are plotted as a function of ...

The consequences of Maternal Mortality (MM) cannot be overemphasized. It inhibits population growth resulting into loss of lives among others. This work tends to obtain the maternal mortality rates (MMR) in Nigeria, identify some fitted distributions to MMR and determine which of the distributions best fits the data. A comprehensive Exploratory Data Analysis (EDA) was carried on MM and the MMRs...

In this paper we define the method used to merge high resolution multi-sensor chlorophyll-a data on the Ireland-Biscay-Iberia Regional Ocean Observing System (IBIROOS) area from 1998 to present at a resolution of 1.1 km. The method is based on geostatistics and is known as kriging. The merged variable is the daily anomaly of chlorophyll-a, the anomaly being defined as the difference between the...

An exponential dominating set of graph $G = (V,E )$ is a subset $Ssubseteq V(G)$ such that $sum_{uin S}(1/2)^{overline{d}{(u,v)-1}}geq 1$ for every vertex $v$ in $V(G)-S$, where $overline{d}(u,v)$ is the distance between vertices $u in S$ and $v  in V(G)-S$ in the graph $G -(S-{u})$. The exponential domination number, $gamma_{e}(G)$, is the smallest cardinality of an exponential dominating set....