Ore-reserve estimations of deposits with low mineral concentrations, such as those of copper, gold and tin, are usually made on the assumption that the grades follow a lognormal distribution. Multiple mineralization or reworking of a deposit may have modified the simple distribution expected — producing an overall distribution of grades which can be adequately described by a mixture of lognorma...

We consider the problem of interval estimation and testing for the difference between the quantiles of two populations. Inferential procedures based on the generalized variable approach are given for the normal and exponential cases. The generalized variable approach produced exact procedures for the normal case with some restrictions on the parameter space and exact procedures for the exponent...

The ordinary variable inspection plans rely on the normality of the underlying populations. However, often this assumption is vague or even not satisfied. A new variable inspection plan is constructed that can be applied for continuous distributions with medium to long tails and that requires relatively moderate sample sizes only. The main idea is that nonconforming items occur in the tails of ...

We study the Potts model on locally tree-like random graphs of arbitrary degree distribution. Using a population dynamics algorithm we numerically solve the problem exactly. We confirm our results with simulations. Comparisons with a previous approach are made, showing where its assumption of uniform local fields breaks down for networks with nodes of low degree.

We show how networks modify the diffusion curve by affecting its symmetry. We demonstrate that a network's degree distribution has a significant impact on the contagion properties of the subsequent adoption process, and we propose a method for uncovering the degree distribution of the adopter network underlying the dissemination process, based exclusively on limited early-stage penetration data...

in this study, the spatial distribution of overwintered adults of sunn pest, eurygaster integriceps puton, was investigated by using dispersion parameters and indices, mathematical distribution, and regression techniques in rainfed wheat fields by sample size of 1 m2 in 2009 and 2010. the dispersion parameters including: mean-variance test and clumping parameter () showed that the overwintered ...

The population dynamics of single species can be understood only in the context of interactions within an ecological community. In this study we used theoretical and empirical models to describe the spatial pattern of the Afrotropical leaf beetles Mesoplatys ochroptera Stål, Exosoma and Ootheca spp. defoliating the agroforestry tree (Sesbania sesban (L.) Merril). We used the Poisson, negative b...