The problem of correctly interpreting data on the mean age of people’s death in different historical periods based on information presented in Wikipedia and included in the Personalities of the Encyclopedia Historical Database is considered. The specificity of these data associated with censoring and the nature of their collection that lead to selectivity is noted. An approach is proposed that takes into account these circumstances, which makes it possible to clarify the obtained patterns of life expectancy and expand the historical range of research.

In practical applications of automatic control theory, one often deals with situations where the controls must range in some domain, in particular, take only nonnegative values. In this case, popular synthesis methods such as modal and optimal control are not applicable. We propose methods for stabilizing the output variables in linear time-invariant SISO systems under nonnegative (unilateral) control constraints. The main idea is to implement the controls in the form of saturated linear functions whose saturation values coincide with the constraints on the controls. As an illustration of our algorithms, a pulsed DC voltage converter with an on/off switch control is considered. The results of simulation in Matlab Simulink are presented.

We propose a new graph model of transportation on a single-line railway section. Based on a given freight-train delivery schedule, we construct an acyclic graph with vertices denoting deliveries and arcs indicating the possibility of successive implementation of these deliveries by some locomotive. This model of the problem permits applying static graph algorithms to find an optimal locomotive assignment plan. The search for a solution of the problem without time constraints on the locomotives is reduced to finding a minimal path cover of an acyclic graph. Each path in the cover corresponds to a sequence of deliveries carried out by one locomotive. If there are temporary constraints on the locomotives (maintenance breaks), not all paths in the cover can remain valid: for some locomotives, none of the established delivery sequences can be performed from start to finish. In this case, one more solution stage is added, at which the cover is transformed in such a way that all new paths describe a sequence of deliveries that can be carried out by a given set of locomotives under given time constraints.

The modern state of the theory of business processes is analyzed, its main directions are classified. The problem of parallelism in business processes is analyzed, and classes of parallel business processes are identified and analyzed. Requirements for business process modeling languages are formulated. As the basis of the conceptual model of the parallel business process modeling language, we propose a model of DFD technology that integrates structural models of various purposes based on a DFD diagram, and allows you to reflect the functional, informational, and behavioral aspects of the simulated object. The article also analyzes the syntax, semantic and pragmatic aspects of the in-troduced modeling language. For a formal description of the syntax, it is pro-posed to use the apparatus of mixed grammars, which are a combination of graph and normal grammars. The article describes the grammar that generates the simplest dialect of DFD technology, informally describes the semantic aspects of the language, in particular the semantics of relations between objects of the language.