The article substantiates the application of cluster analysis method on empirical data. A system indicators agricultural production has been designed. multidimensional grouping by was carried out, regions were grouped into clusters according to level resource provision in industry, effectiveness and efficiency production, its technical, scientific potential support. characteristics each are giv...

We present a quasi-analytic perturbation expansion for multivariate N dimensional Gaussian integrals. The perturbation expansion is an infinite series of lower-dimensional integrals (one-dimensional in the simplest approximation). This perturbative idea can also be applied to multivariate Student-t integrals. We evaluate the perturbation expansion explicitly through 2 order, and discuss the con...