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## АНАЛИЗ ПРОИЗВОДИТЕЛЬНОСТИ СТРАТЕГИЙ СИНХРОНИЗАЦИИ ПОТОКОВ В СТРУКТУРАХ ДАННЫХ, ОСНОВАННЫХ НА FLAT-COMBINING

Deals with the development of threads synchronizing strategies based on the creation of concurrent «flat-combining» data structures as well as research of their performance. The paper considers «flat-combining» approach and its implementation in the library libcds, the development of thread synchronization strategy and its possible implementations. The efficiency of synchronization strategies usage is researched on the example of the open source library libcds. The research revealed the strategy with the lowest operation execution time on a container and the lowest amount of CPU resources, and identifies use cases of the developed strategies. A mechanism with the developed synchronization strategy to build concurrent data structures was implemented. The implemented strategies were integrated in the cross-platform open source library libcds.

The 12th issue of LNCS Transactions on Petri Nets and Other Models of Concurrency (ToPNoC) contains revised and extended versions of a selection of the best papers from the workshops held at the 37th International Conference on Application and Theory of Petri Nets and Concurrency (Petri Nets 2016, Toruń, Poland, 19–24 June 2016), and the 16th International Conference on Application of Concurrency to System Design (ACSD 2016, Toruń, Poland, 19 – 24 June 2016). It also contains one paper submitted directly to ToPNoC.

This book constitutes the proceedings of the 21st International Symposium on String Processing and Information Retrieval, SPIRE 2014, held in Ouro Preto, Brazil, in October 2014. The 20 full and 6 short papers included in this volume were carefully reviewed and selected from 45 submissions. The papers focus not only on fundamental algorithms in string processing and information retrieval, but address also application areas such as computational biology, Web mining and recommender systems. They are organized in topical sections on compression, indexing, genome and related topics, sequences and strings, search, as well as on mining and recommending.

The article is devoted to inclusion of the topic "parallel computing" in the school informatics . Some methodical materials prepared in the course of work on the "Permian version" of a propaedeutic course of computer science (the author team is M.A. Plaksin, N.I. Ivanova, O.L. Rusakova) are described.

This paper presents two new approaches to solving a classical NP-hard problem of maximum clique problem (MCP), which frequently arises in the domain of information management, including design of database structures and big data processing. In our research, we are focusing on solving that problem using the paradigm of artificial neural networks. The first approach combines the artificial neuro-network paradigm and genetic programming. For boosting the convergence of the Hopfield neural network (HNN), we propose a specific design of the genetic algorithm as the selection mechanism for terms of the HNN energy function. The second approach incorporates and extends the tabu-search heuristics improving performance of network dynamics of so-called tabu machine. Introduction of a special penalty function in tabu machine facilitates better evaluation of the search space. As a result, we demonstrate the proposed approaches on well-known experimental graphs and formulate two hypotheses for further research.

We consider the problems of computing the maximal and the minimal non-empty suffixes of substrings of a longer text of length . n. For the minimal suffix problem we show that for every . τ, . 1≤τ≤logn, there exists a linear-space data structure with . O(τ) query time and . O(nlogn/τ) preprocessing time. As a sample application, we show that this data structure can be used to compute the Lyndon decomposition of any substring of the text in . O(kτ) time, where . k is the number of distinct factors in the decomposition. For the maximal suffix problem, we give a linear-space structure with . O(1) query time and . O(n) preprocessing time. In other words, we simultaneously achieve both the optimal query time and the optimal construction time. © 2015 Elsevier B.V.

We study the following three problems of computing generic or discriminating words for a given collection of documents. Given a pattern $P$ and a threshold $d$, we want to report (i) all longest extensions of $P$ which occur in at least $d$ documents, (ii) all shortest extensions of $P$ which occur in less than $d$ documents, and (iii) all shortest extensions of $P$ which occur only in $d$ selected documents. For these problems, we propose efficient algorithms based on suffix trees and using advanced data structure techniques. For problem (i), we propose an optimal solution with constant running time per output word.

The article deals with the development of threads synchronizing strategies based on the creation of concurrent “flat-combining” data structures as well as research of their performance. The paper considers “flat-combining” approach and its implementation in the library libcds, the development of thread synchronization strategy and its possible implementations. The efficiency of synchronization strategies usage is researched on the example of the open source library libcds. The research revealed the strategy with the lowest operation execution time on a container and the lowest amount of CPU resources, and identifies use cases of the developed strategies. A mechanism with the developed synchronization strategy to build concurrent data structures was implemented. The implemented strategies were integrated in the cross-platform open source library libcds.

We study a new variant of the string matching problem called {\em cross-document string matching}, which is the problem of indexing a collection of documents to support an efficient search for a pattern in a selected document, where the pattern itself is a substring of another document. Several variants of this problem are considered, and efficient linear-space solutions are proposed with query time bounds that either do not depend at all on the pattern size or depend on it in a very limited way (doubly logarithmic). As a side result, we propose an improved solution to the {\em weighted level ancestor} problem.

This book constitutes the refereed proceedings of the 23rd Annual Symposium on Combinatorial Pattern Matching, CPM 2012, held in Helsinki, Finalnd, in July 2012. The 33 revised full papers presented together with 2 invited talks were carefully reviewed and selected from 60 submissions. The papers address issues of searching and matching strings and more complicated patterns such as trees, regular expressions, graphs, point sets, and arrays. The goal is to derive non-trivial combinatorial properties of such structures and to exploit these properties in order to either achieve superior performance for the corresponding computational problems or pinpoint conditions under which searches cannot be performed efficiently. The meeting also deals with problems in computational biology, data compression and data mining, coding, information retrieval, natural language processing, and pattern recognition.

A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material for manufacturing industry located in another region, and there is another node station. The organization of freight traﬃc is performed by means of a number of technologies. These technologies determine the rules for taking on cargo at the initial node station, the rules of interaction between neighboring stations, as well as the rule of distribution of cargo to the ﬁnal node stations. The process of cargo transportation is followed by the set rule of control. For such a model, one must determine possible modes of cargo transportation and describe their properties. This model is described by a ﬁnite-dimensional system of diﬀerential equations with nonlocal linear restrictions. The class of the solution satisfying nonlocal linear restrictions is extremely narrow. It results in the need for the “correct” extension of solutions of a system of diﬀerential equations to a class of quasi-solutions having the distinctive feature of gaps in a countable number of points. It was possible numerically using the Runge–Kutta method of the fourth order to build these quasi-solutions and determine their rate of growth. Let us note that in the technical plan the main complexity consisted in obtaining quasi-solutions satisfying the nonlocal linear restrictions. Furthermore, we investigated the dependence of quasi-solutions and, in particular, sizes of gaps (jumps) of solutions on a number of parameters of the model characterizing a rule of control, technologies for transportation of cargo and intensity of giving of cargo on a node station.

Event logs collected by modern information and technical systems usually contain enough data for automated process models discovery. A variety of algorithms was developed for process models discovery, conformance checking, log to model alignment, comparison of process models, etc., nevertheless a quick analysis of ad-hoc selected parts of a journal still have not get a full-fledged implementation. This paper describes an ROLAP-based method of multidimensional event logs storage for process mining. The result of the analysis of the journal is visualized as directed graph representing the union of all possible event sequences, ranked by their occurrence probability. Our implementation allows the analyst to discover process models for sublogs defined by ad-hoc selection of criteria and value of occurrence probability

The geographic information system (GIS) is based on the first and only Russian Imperial Census of 1897 and the First All-Union Census of the Soviet Union of 1926. The GIS features vector data (shapefiles) of allprovinces of the two states. For the 1897 census, there is information about linguistic, religious, and social estate groups. The part based on the 1926 census features nationality. Both shapefiles include information on gender, rural and urban population. The GIS allows for producing any necessary maps for individual studies of the period which require the administrative boundaries and demographic information.

Existing approaches suggest that IT strategy should be a reflection of business strategy. However, actually organisations do not often follow business strategy even if it is formally declared. In these conditions, IT strategy can be viewed not as a plan, but as an organisational shared view on the role of information systems. This approach generally reflects only a top-down perspective of IT strategy. So, it can be supplemented by a strategic behaviour pattern (i.e., more or less standard response to a changes that is formed as result of previous experience) to implement bottom-up approach. Two components that can help to establish effective reaction regarding new initiatives in IT are proposed here: model of IT-related decision making, and efficiency measurement metric to estimate maturity of business processes and appropriate IT. Usage of proposed tools is demonstrated in practical cases.