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Decision tree learning algorithms have a long history, but they are still popular due to their efficiency. Tree construction starts at the root and continues to each leaf node, creating a “near-optimal” tree. One of the key steps in creating a decision tree is the selection of a feature to split at each root node, which affects the classification accuracy. This process can be quite labor intensive. The article proposes a new approach to constructing decision trees based on the use of differential evolution for two-level tree optimization. Differential evolution works in two stages: at the first level, a feature is selected for separation, and at the second level, the threshold value for this feature is optimized. The results of the work were tested on several examples of classification problems.

The most important factor affecting the yield of agricultural crops is the formation of an optimal water regime in the active soil layer. One of the main methods of carrying out such works is sprinkling, since it is closest to the process of natural precipitation. At the same time, existing water sprinklers do not provide watering agricultural lands that meets agro-technological requirements due to the design features and the specifics of the landscape on which they are used, forming in the process of watering zones with excessive and insufficient moisture. In this regard, a positional water sprinkler has been developed, which has the ability to water along a path close to rectangular. Obtaining this trajectory is achieved due to the design features obtained as a result of mathematical modeling. The article presents the structural diagram of the developed water sprinkler, considers the principle of its operation, presents the results of mathematical analysis and modeling of kinematic processes occurring during its operation. The above research results show that the use of the proposed water sprinkler will improve the quality of watering due to the watering trajectory closest to rectangular.

Issues are presented concerning the adverse comments made on television by ORT board member and deputy general director Sergei Dorenko concerning the handling of the Kursk submarine accident by Russian President Vladimir Putin.

The Nizhny Novgorod province of Russia is instituting economic reforms initiated by Grigory Yavlinsky and the Center for Economic Policy and Research (EPI). These reforms include the issuance of bonds to pay part of the wages of state enterprise employees. Bonds will be redeemed by the government when cash becomes available. The EPI group is also introducing agricultural reforms and reevaluating province statistics to identify all possible resources. Yavlinsky is testing the viability of market reforms tailored to the specific features of the region by experimenting on the province level with the support of Governor Boris Nemtsov.