Vol 78, No 11 (2017)

We propose a solution for the modal controllability problem for linear autonomous differential systems of neutral type with commensurate delays in two classes of differentialdifference controllers.

For a version of the generalized Kuramoto–Sivashinsky equation with “violated” symmetry, the periodic boundary value problem was investigated. For the given dynamic distributed-parameter system, consideration was given to the issue of local bifurcations at replacing stability by spatially homogeneous equilibrium states. In particular, the bifurcation of the two-dimensional local attractor with all Lyapunov-unstable solutions on it was detected. Analysis of the bifurcation problem relies on the method of the integral manifolds and normal forms for the systems with infinitely dimensional space of the initial conditions.

To improve the reliability of data delivery, in Wi-Fi networks stations can reserve for their transmissions periodic time intervals of the same duration in which they are allowed to transmit, while adjacent stations do not have that right. Here there arises the problem of choosing the parameters of reserved intervals that would ensure quality of service requirements for transmitted data in the smallest possible amount of reserved channel time. We consider the data transmission process in periodic intervals with the block acknowledgement policy that lets us reduce the costs by acknowledgement the set of packets with a single service message. We propose a method for mathematical modeling of such a transmission.

A mathematical model of joint servicing of the multiservice real time traffic and elastic data traffic with batch arrival of requests was constructed and investigated. The definitions of the performance measures of joint requests servicing were formulated, and their interrelations established. An algorithm to estimate numerically the characteristics of a model based on construction and solution of the equilibrium equations system was developed. Consideration was given to some partial cases of the model for which convenient recursive algorithms to calculate the measures of joint requests servicing were constructed. A method to estimate the desired rate of data transmission was proposed on the basis of the asymptotic properties of the model under light load. Numerical examples illustrating the distinctions of realizing the developed computer procedures were described.

For the multinomenclature EOQ reserve control model with renting storage space and delayed payment for the orders, we propose an approach to optimization that accounts for the temporal value of money. We estimate the influence of these delays both on the parameters of the optimal control strategy and on the efficiency of using floating capital. The study has been done for situations when the said delays let one pay for orders from the revenue on repeat order intervals. We establish a necessary and sufficient condition imposed on the duration of delays that guarantees that this order payment from the revenue is possible. We illustrate characteristic features of optimization procedures with numerical computations.

We propose search algorithms for paths in graphs that are optimal in the sense of a given choice function. As an example we consider the choice mechanism with respect to a binary relation that does not contain numerical criterial estimates.

We propose an alternative approach to classification that differs from known approaches in that instead of comparing the tuple of values of a test object’s features with similar tuples of features for objects in the training set, in this approach we make independent pairwise comparisons of every pair of feature values for the objects being compared. Here instead of using the notion of a “nearest neighbors” for test object, we introduce the notion of “admissible proximity” for each feature value in the test object. In this approach, we propose an alternative algorithm for classification that has a number of significant practical features. The algorithm’s quality was evaluated on sample problems taken from the well-known UCI repository and related to various aspects of human activity. The results show that the algorithm is competitive compared to known classification algorithms.

The paper considers the properties and design method of an extended two-dimensional multiring with an increased number of nodes and independent paths between nodes.

The paper discusses the modeling of emergency control system of turbine frequency and power regulators using a hybrid real time simulator of electric power system. It presents the results of pilot simulation of frequency and power regulators ensuring dynamic and static stability in an electric power system.