An approach for systems integration and components of advanced technology under the changing landscape of the global energy economy is shown. The paper presents the basic procedure for determining the adaptive infrastructure solutions in the implementation of intellectual environment of multiaspect modeling (virtual semantic environment). The relevant techniques for systems integration and simulation in this project are: regenerative analysis, data envelopment analysis, analytic hierarchy process, methods for constructing a hierarchy, analytic network process, and others. In this paper the possibility of applying the generalized data envelopment analysis model for electric-distribution utilities are shown.

В связи с возрастанием значения возобновляемых источников энергии все большее внимание уделяется технологиям преобразования этой энергии в электрическую, в частности микро-ГЭС. В статье представлен обзор существующих методов управления асинхронными генераторами, являющимися электромеханическим преобразователями энергии водяного потока. Основной задачей управления является стабилизация выходного напряжения и частоты выходного напряжения генератора при работе в автономном режиме при изменяемой нагрузке. Одним из наиболее популярных решений, используемых для управления выходным напряжением, является конденсаторное, основанное на использовании батарей конденсаторов, переключаемых в зависимости от нагрузки. В настоящее время начинают широко использоваться решения, основанные на использовании полупроводниковых преобразователей энергии, включаемых, как в прямую цепь преобразования энергии, так и параллельно ей в режиме компенсации реактивной мощности (СТАТКОМ).

We investigate a polling model for a radio-cell of the broadband wireless IEEE 802.11 DCF network. A radio-cell is assumed to work in the "data collection" regime. It is modelled by the polling system with N queues and a single server polling the queues in a cyclic adaptive order. Under adaptive scheme, the server (base station) skips (does not visit) the queues (subscriber stations) which were empty at their polling moments at the previous cycle that allows cutting expenses. In the paper, we present an iteration procedure to calculate the mean waiting time in queues and provide numerical examples to compare theoretical results and ones obtained from simulation.

This paper presents a queueing model that provides a performance upper-bound for Multi-rate Downlink SDMA systems. It is shown that the performance of Downlink SDMA systems depends to a great extent of parameters such as the number of active users, the traffic arrival process, the queue size, the number of antennas and the set of available transmission rates. Using this upper-bound as a reference, the situations in which a Downlink SDMA system is able to near attain the upper-bound performance are discussed.

The development of random multiple access (RMA) algorithms, which are based on the successive interference cancellation (SIC) has attracted attention of scientists in the last years. In this paper a new RMA algorithm for centralized networks, which we refer to as Multi-FS-TREE/SIC is introduced and analyzed. The algorithm is a combination of Multi-FS-ALOHA and SICTA and provides transmission rate more than 0.6.