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“Informatics and Applications” scientific journalVolume 6, Issue 3, 2012Content Abstract and Keywords About Authors RADIO SOURCES STUDY WITH THE VIRTUAL OBSERVATORY TOOLS.
Abstract: During a number of years (19801999), using different approaches on the basis of the Virtual Observatory means, the study of sources of the surveys was conducted on the largest Russian radio telescope RATAN-600. Their bulk identification is executedwith themaximumuse of data for different ranges of an electromagnetic spectrumavailable in open access. With the use of the Virtual Observatory program tools, the approach on automatic preparation and preliminary data processing is realized. The information system is developed for the resulting compilative catalogue preparation that was applied in the analysis of information on each source andmaking decision on its identification. Based on the experience gained while working with numerous heterogeneous resources, the author summarizes that the Virtual Observatory infrastructure provides convenient access to astronomical resources and significantly increases the efficiency of scientific research. However, there are still no advanced tools for further analysis, updating and publication of data collected by the researcher. A number of projects is being developed to implement the most linked data based on already existing Web technologies and that will transfer the Virtual Observatory services to a new level of knowledge exchange through annotation of catalogue entries and the implementation of links between them. Keywords: virtual observatory; distributed information system; computer science technology in scientific research; integration of diverse information resources; databases METHODOLOGICAL ASPECTS OF DEVELOPMENT OF THE ELECTRONIC RUSSIANENGLISH THESAURUS ON COMPUTATIONAL LINGUISTICS .
Abstract: The paper discusses methodological aspects of development of the electronic RussianEnglish thesaurus on computational linguistics. Rationale for the creation of the thesaurus, and the design principles are substantiated. The general structure of the thesaurus, composition of the thesaurus entries, and set of relations between the thesaurus terms are described. The procedure of choice of terms for inclusion in the thesaurus is depicted and the problems with selection of the preferred term(descriptor) from a synonyms list as well as translation equivalents are discussed. Features of implementation of online digital version of the thesaurus are considered. The paper gives a particular attention to maintenance of a logical consistency of the thesaurus terminology system and to providing a convenient access to the thesaurus content. Keywords: multilingual thesaurus; computational linguistics; methodology for thesaurus development; ontology; conceptual model of the thesaurus; scientific knowledge portal technology CLASSIFICATION AND UTILIZATION OF SEMANTIC LINKAGES BETWEEN INFORMATION OBJECTS IN SCIENTIFIC DIGITAL LIBRARIES .
Abstract: An approach to increase the information value of scientific digital library by supporting the classified semantic linkages between its information objects is discussed. An implementation of the proposed approach is based on the domestic Socionet system that integrates a large number of scientific digital libraries and which is used de facto as a research information space of the Social Science Division of the Russian Academy of Sciences. Keywords: digital library; information object; collection of information resources; semantic linkage; linkage classifier; ontology; scientometrics INTEGRATION OF GEOGRAPHIC METADATA USING RETROSPECTIVE THESAURUS.
Abstract: The questions, related with the development of interoperable thesaurus of geographic names, with geometric and retrospective data included in, are discussed. The basic requirements to the thesaurus are defined. An overview of existing solutions is provided and the main positions for thesaurus access profile have been formulated. The relational database schema for thesaurus data is described. Keywords: geographical metadata; integration; retrospective geocoding; thesaurus UNIVERSAL SYSTEM OF PLAGIARISM DETECTION AUTOR.NET.
Abstract: The problem of duplicate texts detecting is discussed. The basic approaches to detection of text duplicates are given. The existing programs of duplicate texts detecting have been reviewed. An overview of methods to conceal the evidence of plagiarism is presented. A system Autor.NET which checks the text duplications founded on the internal base of the sources and on Internet has been created. Keywords: plagiarism; detection of plagiarism; copying FRACTIONAL LEVY MOTION WITH DEPENDENT INCREMENTS AND ITS APPLICATION TO NETWORK TRAFFIC MODELING.
Abstract: Since the beginning of the 1990s, accurate traffic measurements carried out in different network scenarios highlighted that Internet traffic exhibits strong irregularities (burstiness) both in terms of extreme variability and long-term correlations. These features, which cannot be captured in a parsimonious way by traditional Markovian models, have a deep impact on the network performance and lead to the introduction of -stable distribution and self-similar processes into the network traffic modeling. In this paper, a generalization of fractional Brownian motion, which is able to capture both above-mentioned features of the real traffic, is considered. Keywords: fractional Brownian motion; -stable subordinator; self-similar processes; buffer overflow probability ABOUT THE RATE OF CONVERGENCE OF ONE U-STATISTIC.
Abstract: This paper pertains to the analysis of the asymptotic behavior ofU-statistics, which are important in the construction and application of modern statistical methods for studying information systems. Keywords: rates of convergence; BerryEsseen bound; quadratic form; second-degree U-statistics; Kolmogorov distance ESTIMATES OF THE RATE OF CONVERGENCE OF THE DISTRIBUTIONS OF RANDOM SUMS TO VARIANCE-GAMMA DISTRIBUTIONS.
Abstract: The estimates are constructed for the accuracy of the approximation of the distributions of special random sums of independent random variables with nonzero means by variance-gamma distributions. Keywords: random sum; negative binomial distribution; gamma-distribution; convergence rate estimate; mixed Poisson distribution; variance-gamma distribution CROSS-LAYER OPTIMIZATION PLANNING PROBLEMS IN WIRELESS NETWORKS.
Abstract: The review provides the state-of-the-art of the cross-layer optimization problems for the Orthogonal Frequency Division Multiplex technology of Long-Term Evolution wireless networks. The notion of cross-layer optimization is considered, the detailed optimization problems and its constraints arising from the radio resources allocation in the downlink are investigated, and the brief discussion of schedulers and its utilization functions are presented. Keywords: OFDM; cross-layer optimization; utility function; efficient frequency allocation ASYMPTOTICS OF THE MAXIMUM WORKLOAD FOR A CLASS OF GAUSSIAN QUEUEING SYSTEMS.
Abstract: The asymptotics of the maximum workload in a fluid queueing system fed by a process containing a random component are described by a centeredGaussian process. It is assumed that the variance of the process is a regularly varying at infinity function with index belonging to interval (0, 2). Such class of processes includes, in particular, a sum of independent fractional Brownian motions. It is shown that, under an appropriate scaling, the maximum workload over interval [0, t] converges in probability to an explicitly given constant as t increases. Keywords: Gaussian queueing system; maximum workload; fractional Brownian motion; asymptotical analysis; regular variation ON THE ESTIMATION OF THE OVERFLOW PROBABILITY IN REGENERATIVE FINITE BUFFER QUEUEING SYSTEMS.
Abstract: A few aspects of the regenerative estimation of the stationary overflow probability in finite buffer system are considered. A proof of a general relation connecting the loss probability and idle probability in stationary regime is given. An application of this result to a broad class of loss systems, in particular, to a retrial system with constant retrial rate, is shown. An efficiency of this relation for regenerative estimation of the loss probability under different traffic regimes and also with use of k-regenerations, appearing in the analysis of non-Markovian systems, is studied. The numerical results of estimation are given. Keywords: finite buffer systems; loss probability; idle probability; regenerative estimation; k-regenerations; retrial queueing system STOCHASTIC MODELS OF MULTIPROCESSOR SYSTEMS: STABILITY AND MOMENT PROPERTIES.
Abstract: The basic models of multiprocessor systems in which each job requires a random number of processors have been studied. A new model of such system is proposed and studied, where, for a given job, all processing times are identical. This assumption reflecting real service process makes the analysis of the system more difficult. To investigate the model, some minorant and majorant (classical) systems are constructed, which allow, for a few important particular cases, to obtain both stability conditions and the moment properties of the original stationary workload process. Keywords: multiprocessor systems; random number of processors; identical processing times; stability conditions; moment properties; stationary workload; high performance cluster A RESTRICTION ON THE TOTAL VOLUME OF DEMANDS IN THE DISCRETE-TIME SYSTEM
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