SUMMARY The evaluation of volume integrals that arise in boundary integral formulations for non‐homogeneous problems was considered. Using the “Galerkin vector” to represent the Green's function, the volume integral was decomposed into a boundary integral, together with a volume integral wherein the source function was everywhere zero on the boundary. This new volume integral can be evaluated using a regular grid of cells covering the domain, with all cell integrals, including partial cells at the boundary, evaluated by simple linear interpolation of vertex values. For grid vertices that lie close to the boundary, the near‐singular integrals were handled by partial analytic integration. The method employed a Galerkin approximation and was presented in terms of the three‐dimensional Poisson problem. An axisymmetric formulation was also presented, and in this setting, the solution of a nonlinear problem was considered. Copyright © 2012 John Wiley & Sons, Ltd.

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In recent years, increasing effort has been devoted to the study of virtual world economies due to their potential of increasing our understanding of the real world economy, and vice versa. Due to a scarce availability of reliable global data, previous virtual world economic studies have been largely limited to qualitative observations. This paper presents novel financial data and is the first to apply a time series approach to the forecasting of virtual commodity prices. The results are assessed against the random walk and, from an efficient markets perspective, evaluates the potential of virtual worlds becoming experimental simulations for the real.