Today, changeable requirements to modern web-oriented services demand their fast development and constant reengineering. This is realized via dynamic composition of services, allowing to estimate changes of both functional and nonfunctional service parameters. The last ones are considered using Web Services Agreement technique. Nevertheless, state-of-the-art SLA-aware methods are not able to consider all classes of non-functional parameters. They also don't provide service run-time support and dynamic reconfiguration. The novel approach to dynamic Web Services Composition, extending SLA with QoS ontology, is described in the paper. It includes service selection agents that use the QoS ontology and WS-Agreements, allowing agents to choose the most appropriate service based on quality preferences exposed by service consumer. The proposed approach allows performing dynamic WS composition based on SLA, providing required values of QoS parameters, improving general QoS and decreasing service development and re-engineering time.

Asymptotic properties of self-similar traffic models based on discrete-time and continuous-time martingales are considered. We discovered that their performance indicators are asymptotically equal at lambda -> inf to indicators for model based on Brownian motion.

The article is devoted to the estimation of threshold values, regulated by ITU, which determine the necessity of satellite networks coordination in the Ku band. Maximum capacity of geostationary orbit (GEO) for different diameters of earth station antennas, operating in standard DVB-S2 accounting the limitations caused by the parameters of existing satellite networks equipment, is determined. Optimal values of satellites' orbital separation, relative increase in allowable noise DELTA T/T and the signal to single-interference ratio C/I were identified for maximum GEO capacity.

The paper provides an overview of information transmission methods through the use of the noise carrier proposed by researchers from the middle of the last century to the present day. It is shown that the main areas of application of autocorrelation systems with the noise carrier is the confidential communication system construction, where the protection of the transmitted information from intercepting and protection of the channel from the extraneous information injecting are of priority. Methods of information transfer, discussed in the paper, allow solving the problem of sustainable communication in difficult conditions of signal propagation with simple technical means, especially in multipath channels. The paper studies the most urgent theoretical and practical problems relating to communication systems with the noise carrier.

The present paper addresses essential discourse elements of the English language of science in light of the so-called Anglo-American intellectual style. Emphasised here are: various linguistic devices of compression (writing succinctly, avoiding verbosity and negation etc.), keeping subject and verb close together, and common revision patterns. Key standardized discourse models and academic vocabulary - as well as their Ukrainian equivalents - are also discussed. Special attention is given to Active vs. Passive voice usage, and adequate language framing of the author's viewpoint in scientific discourse.

Індекс рубрикатора НБУВ: З811.2

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Шифр НБУВ: Ж100651 Пошук видання у каталогах НБУВ 

This paper presents a comparative analysis of the multiplexing principles, allowing increasing the technical efficiency of radio resource usage based on the three-dimensional signals spatial separation in a spherical coordinate system. These methods allow creating spatial multichannel communications between certain points (areas) of the space through the radiators and signal processing system of wireless base station. Three-dimensional spatial selectivity in spatial matched filtration is provided by the physical processes of the focusing and the differentiation signals by their front curvature, and in the spatial correlation signal processing - by orthogonality of spreading sequences, their reusing by cyclic shift and synchronization, depending on the distance from the base to the mobile station.

Our high-tech XXI century is, in particular, the century of "small powe supply systems" due to the use of advanced information and communication technologies in energy networks. Creation of combined systems called Smart Grid opens great prospects for the development of both of these industries (energy and IT) and is intended to provide a synergetic effect. This paper examines existing models of Smart Grid, the suitable basic networking technologies, as well as typical usage scenarios for integrated intelligent networks.