Physical activity ot elderly people in an ageing society is a condition for their social and economic activity, which helps reduce the negative consequences of population ageing. Physical education lessons help to maintain health and it is a form of leisure for a pensioner. However, the Russian sports and health services market for senior consumers is still underdeveloped. The marketing study results allow to conclude that the development rate of the domestic sports and health services market for senior consumers does not correspond to the Russian population ageing rate. The study also established the factors constraining the market development: the solvency of the consumer, as well as negative stereotypes about elderly people. During the analysis of Russian sports and health services market companies for senior consumers marketing opportunities were found, as well as tasks to be solved within the government policy in the population ageing conditions.

Recommender systems provide recommendations for users. In this paper, we train and test some algorithms for recommender systems on a certain dataset, as well as analyze their strengths and weaknesses. Based on this information, we construct a system that yields a better solution.

The experiments conducted by various scientic groups indicate that, in dense two-dimensional systems of elongated particles subjected to vibration, the pattern formation is possible. Computer simulations have evidenced that the random walk of rectangular particles in a discrete two-dimensional space can lead to their self-organisation. We propose a technique for calculating the entropy characteristics of a two-dimensional system in a discrete two-dimensional space consisting of rectangular particles of two mutually perpendicular orientations, and a change in these characteristics for a random walk of particles is investigated.

In current work we propose some algorithms of long-range connections evaluation. Firstly, we reconstruct an initial graph into the graph of directed intensities. This approach is based on the individual and the group influence with respect to nodes characteristics. Secondly, we apply different models of the indirect influence estimation based on simple paths and random walks. This can help us to estimate node-to-node influence in networks. Finally, we aggregated the results of node-to-node influence into the influence index. The model is applied to the food trade network based on World International Trade Solution database. The results are compared with classical centrality measures that were applied to initial network and to the network of directed intensities.

To evaluate the stress field in the Martian interior a static-state approach is applied. We use trial interior structure model having 150–300 km thick lithosphere overlying a low rigidity layer, which partly lost elastic properties. Calculations of stresses are performed with spatial resolution a 1 × 1 arc-deg spherical grid and down to 1000 km depth. Stress estimates are calculated in the interiors of the planet under local topography structures, these areas are of interest to reveal the zones of possible marsquakes sources. Large non-hydrostatic stresses under Hellas Planitia, Argyre Planitia, Mare Acidalia, Arcadia Planitia and canyon Valles Marineris may lead to relatively increased seismic activity for these regions.