Статьи журнала - Программные системы: теория и приложения

Все статьи: 371

A model and algorithm for sequence alignment

A model and algorithm for sequence alignment

Znamensky Sergey Vitalyevich

Статья

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A note on migration perturbation and convergence rates to a steady state

A note on migration perturbation and convergence rates to a steady state

Blume Lawrence Edward, Lukina Aleksandra Andreevna

Статья научная

Using tools developed in the Markov chains literature, we study convergence times in the Leslie population model in the short and middle run. Assuming that the population is in a steady state and reproduces itself period after period, we address the following question: how long will it take to get back to the steady state if the population distribution vector was affected by some shock as, for instance, the “brain drain”? We provide lower and upper bounds for the time required to reach a given distance from the steady state.

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A picture of common subsequence length for two random strings over an alphabet of 4 symbols

A picture of common subsequence length for two random strings over an alphabet of 4 symbols

Znamenskij Sergej Vitalevich

Статья научная

The maximal length of longest common subsequence (LCS) for a couple of random finite sequences over an alphabet of 4 characters was considered as a random function of the sequences lengths and 𝑛; Exact probability distributions tables are presented for all couples of length in a range 2

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An FPGA packet communication protocol

An FPGA packet communication protocol

Adamovich Igor Alekseevich, Klimov Yuri Andreevich

Статья научная

When creating computer boards with FPGA or application-specific chips, it is often needed to connect several chips. Existing available buses do not have all the properties required by the authors' task at hand: packet transmission, using a small number of GPIO pins, sufficient bandwidth.We describe a packet communication protocol that uses GPIO pins and has bandwidth up to 10 MB/s at a frequency of 20 MHz.

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Analytical design of controllers for discrete-continuous systems with linear control

Analytical design of controllers for discrete-continuous systems with linear control

Irina V. Rasina, Oles V. Fesko, Oleg V. Usenko

Статья научная

The study focuses on a certain kind of discrete-continuous systems (DCS): the linear hybrid DCS with state-dependent coefficients. The authors proposed a problem similar to the analytical design of optimal controllers (ADOC). For this study, we generalized the Krotov sufficient optimality conditions. The paper includes several examples.

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Approximate optimal control synthesis for nonuniform discrete systems with linear-quadratic state

Approximate optimal control synthesis for nonuniform discrete systems with linear-quadratic state

Rasina Irina Viktorovna, Fesko Oles Vladimirovich

Статья научная

Nonuniform discrete systems linear-quadratic over its state are the subject of intense study in optimal control theory. This work presents an approximate optimal control synthesis method in this class based on Krotov’s sufficient optimality conditions and illustrates it with a simple example.

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Desktop Grid корпоративного уровня

Desktop Grid корпоративного уровня

Ивашко Евгений Евгеньевич

Статья научная

В работе рассказывается о системах Desktop Grid корпоративного уровня, их возможностях, отличительных особенностях и приложениях. Даны примеры реализации систем промежуточного программного обеспечения, предназначенных для организации корпоративных Desktop Grid.

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Etherbox: a protocol for modular sensor networks

Etherbox: a protocol for modular sensor networks

Shevchuk Yury Vladimirovich, Shevchuk Elena Vasilievna, Ponomarev Alexander Yurievich, Vogt Igor Anatolievich, Elistratov Alexey Viktorovich, Vakhrin Andrey Yurievich, Yarovicyn Roman Evgenievich

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Etherbox: протокол для управления модульной сенсорной сетью

Etherbox: протокол для управления модульной сенсорной сетью

Шевчук Юрий Владимирович, Шевчук Елена Васильевна, Пономарв Александр Юрьевич, Фохт Игорь Анатольевич, Елистратов Алексей Викторович, Вахрин Андрей Юрьевич, Яровицын Роман Евгеньевич

Ред. заметка

Протокол прикладного уровня Etherbox предназначен для взаимодействия управляющего компьютера с узлами сенсорной сети в форме исполняемых программ виртуальной машины, что позволяет обеспечить гибкость в управлении, необходимую для сенсорных сетях с модульной конструкцией узлов. В статье описаны принципы функционирования сенсорной сети, использующей протокол Etherbox, в сравнении с сетями, использующими протоколы MQTT-SN и CoAP. Рассматривается архитектура программного обеспечения снесорных узлов и управляющего компьютера.

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Existence of global fundamental solution to a class of Fokker-Planck equations

Existence of global fundamental solution to a class of Fokker-Planck equations

Markasheva Vera, Mashtakov Alexey

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Global optimization via neural network approximation of inverse coordinate mappings with evolutionary parameter control

Global optimization via neural network approximation of inverse coordinate mappings with evolutionary parameter control

Pushkaryov Kirill Vladimirovich

Статья научная

A hybrid method of global optimization NNAICM-PSO is presented. It uses neural network approximation of inverse mappings of objective function values to coordinates combined with particle swarm optimization to find the global minimum of a continuous objective function of multiple variables with bound constraints. The objective function is viewed as a black box.The method employs groups of moving probe points attracted by goals like in particle swarm optimization. One of the possible goals is determined via mapping of decreased objective function values to coordinates by modified Dual Generalized Regression Neural Networks constructed from probe points.The parameters of the search are controlled by an evolutionary algorithm. The algorithm forms a population of evolving rules each containing a tuple of parameter values. There are two measures of fitness: short-term (charm) and long-term (merit). Charm is used to select rules for reproduction and application. Merit determines survival of an individual. This two-fold system preserves potentially useful individuals from extinction due to short-term situation changes.Test problems of 100 variables were solved. The results indicate that evolutionary control is better than random variation of parameters for NNAICM-PSO. With some problems, when rule bases are reused, error progressively decreases in subsequent runs, which means that the method adapts to the problem.

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Local competing in interpolation problems

Local competing in interpolation problems

Znamenskij Sergej Vitalevich

Статья научная

A simple example illustrates the insufficiency of the known approaches to interpolation in the problem of recovering a function from a few given specific values that clearly convey the form. A local choice between polynomial and rational local interpolants, which minimizes the local interpolant's errors at the nearest external nodes from one or different sides, complements the known approaches. It combines the extreme computational simplicity of local interpolants with the thorought selection of them. The principles of constructing the algorithm are formulated in general terms for mappings of metric spaces. They provide accurate (with rare exceptions) reconstruction of mappings that locally coincide with some of the given possible interpolants. In the one-dimensional case, the two-stage algorithm guarantees the continuity of the interpolant and accurately reconstructs {[itemindent=1cm] polynomials of small degree, simple rational functions with a linear denominator, broken lines of long links with knots at the ends } when these requirements do not contradict each other. An additional parameter allows you to replace the exact restoration of polylines with the required smoothness of interpolation.

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Memory-efficient sensor data compression

Memory-efficient sensor data compression

Shevchuk Yury Vladimirovich

Статья научная

We treat scalar data compression in sensor network nodes in streaming mode (compressing data points as they arrive, no pre-compression buffering). Several experimental algorithms based on linear predictive coding (LPC) combined with run length encoding (RLE) are considered. In entropy coding stage we evaluated (a) variable-length coding with dynamic prefixes generated with MTF-transform, (b) adaptive width binary coding, and (c) adaptive Golomb-Rice coding. We provide a comparison of known and experimental compression algorithms on 75 sensor data sources. Compression ratios achieved in the tests are about 1.5/4/1000000 (min/med/max), with compression context size about 10 bytes.

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Methods for anchoring boundary nodes when smoothing a triangular surface mesh

Methods for anchoring boundary nodes when smoothing a triangular surface mesh

Sergei S. Shumilin

Статья научная

In numerical modeling tasks that use surface meshes, remeshing is often required. However, while remeshing, distortion can occur. The accumulation of distortions can lead to the collapse of the solution. Smoothing algorithms are used to maintain the quality of the mesh during the calculation. When performing smoothing using methods that shift the mesh nodes, the border nodes are usually fixed to avoid distortion. However, simply fixing the nodes can lead to more severe distortion. This paper presents methods for working with boundary nodes to control such nodes during the smoothing process. Algorithms for working with pseudo-3D surface meshes, which are of particular interest, are also considered

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Modern server ARM processors for supercomputers: A64FX and others. Initial data of benchmarks

Modern server ARM processors for supercomputers: A64FX and others. Initial data of benchmarks

Kuzminsky Mikhail Borisovich

Статья обзорная

A comparative analysis of~the performance of~ARM server processors used on~supercomputers or also aimed at~high-performance computing (HPC) is given. Fujitsu A64FX, Marvell ThunderX2 and Huawei Kunpeng 920 were selected for the initial performance analysis. The HPC performance review focuses primarily on~benchmarks and applications for the A64FX, which supports longer vectors than other ARM processors and has higher peak performance. The performance of~the A64FX is compared against corresponding data for Intel Xeon Skylake and Cascade Lake, and AMD EPYC with Zen 2 and 3 (Roma and Milan), as well as Nvidia V100 and A100 GPUs. A~short set of~potential pros and cons of~the A64FX microarchitecture has been formulated. Comparison of~performance data obtained using different compilers for A64FX. Features have been formed when A64FX usually gives advantages in~performance over x86-64, and when it concedes to x86-64. It is clear that the use of~A64FX in~supercomputers can grow further. There is an assumption that x86-64 hegemony in~HPC will decrease, in~particular, due to the increased use of~server ARM processors. But the analysis of~A64FX and new AArch64 processors expected in~the near future showed that A64FX will not necessarily lead in~this process.

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Multiclass Classification in the Problem of Differential Diagnosis of Venous Diseases Based on Microwave Radiometry Data

Multiclass Classification in the Problem of Differential Diagnosis of Venous Diseases Based on Microwave Radiometry Data

Vladislav V. Levshinskii

Статья научная

This article is devoted to applying mathematical models in the differential diagnosis of venous diseases based on microwave radiometry data. A modified approach for transforming feature space in thermometric data is described. After constructing features, a multiclass classification problem is solved in several ways: by reducing to binary classification problems using “one versus rest” and “one versus one” methods and building a multivariate logistic regression model. The best classification model achieved an average balanced accuracy score of 0.574. A key feature of the approach is that classification result can be explained and justified in terms understandable to a diagnostician. This article presents the most significant patterns in thermometric data and the accuracy with which they can identify different classes of diseases.

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Multiple-precision matrix-vector multiplication on graphics processing units

Multiple-precision matrix-vector multiplication on graphics processing units

Isupov Konstantin, Knyazkov Vladimir

Статья научная

We are considering a parallel implementation of matrix-vector multiplication (GEMV, Level 2 of the BLAS) for graphics processing units (GPUs) using multiple-precision arithmetic based on the residue number system. In our GEMV implementation, element-wise operations with multiple-precision vectors and matrices consist of several parts, each of which is calculated by a separate CUDA kernel. This feature eliminates branch divergence when performing sequential parts of multiple-precision operations and allows the full utilization of the GPU's resources. An efficient data structure for storing arrays with multiple-precision entries provides a coalesced access pattern to the GPU global memory. We have performed a rounding error analysis and derived error bounds for the proposed GEMV implementation. Experimental results show the high efficiency of the proposed solution compared to existing high-precision packages deployed on GPU.

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On the free Carnot (2, 3, 5, 8) group

On the free Carnot (2, 3, 5, 8) group

Gauthier Jean-Paul, Sachkov Yuri Leonidovich

Статья научная

We consider the free nilpotent Lie algebra with 2 generators, of step 4, and the corresponding connected simply connected Lie group 𝐺, with the aim to study the left-invariant sub-Riemannian structure on defined by the generators of as an orthonormal frame. We compute two vector field models of by polynomial vector fields in R8, and find an infinitesimal symmetry of the sub-Riemannian structure. Further, we compute explicitly the product rule in and the right-invariant frame on 𝐺.

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Parus - синтаксически аннотированный корпус русского языка

Parus - синтаксически аннотированный корпус русского языка

Власова Наталья Александровна, Трофимов Игорь Владимирович, Сердюк Юрий Петрович, Сулейманова Елена Анатольевна, Воздвиженский Илья Николаевич

Статья научная

В статье представлен новый аннотированный корпус русского языка PaRuS (Parsed Russian Sentences). Корпус имеет объем свыше 2,5 миллиардов токенов и предназначен для решения задач компьютерной лингвистики методами машинного обучения. PaRuS состоит из предложений русского литературного языка. Каждое предложение снабжено лингвистической разметкой: морфологической в формате MULTEXT-East и синтаксической в нотации СинТагРус. В статье рассмотрена методология создания корпуса, описан гибридный лингвистический конвейер PaRuS_pipe, разработанный для порождения разметки. Обсуждаются вопросы качества аннотирования языкового материала в корпусе PaRuS, выполнена оценка морфологического анализатора конвейера PaRuS_pipe по методологии соревнования MorphoRuEval-2017.

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Riak KV performance in sensor data storage application

Riak KV performance in sensor data storage application

Zhivchikova Nadezhda Sergeevna, Shevchuk Yury Vladimirovich

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