Search

The purpose of this paper is a spectrum analysis of signals of various nature, construction of the signal scalogram using Morlet wavelet, modification of the scalogram to obtain a more informative graphic representation of the signal. Spectral analysis of the signal is constructed by means of the Fourier transform. A modification of the graphical representation of the result of the wavelet transform has been developed with the help of the Mathematica system. For this, a wavelet scalogram has been used as a two-dimensional representation of the original signal. A scale has been introduced on it for the value of the signal amplitude depending on the time and period of its constituent components. This graphical representation allows us to obtain additional information about the dynamic properties of the original signal. A modification of the representation of the original signal scalogram has been developed for a more complete spectrum analysis (determination of the period of the constituent components). The paper contains an example using a modified scalogram for the analysis of a signal containing two pulses, an audio signal and white noise. The basic wavelet in this case is the Morlet wavelet. A comparison of the scalogram, obtained using the built-in function, and the modified scalogram has been made in the paper. The disadvantage of the first scalogram is the impossibility of assessing the frequency of the signal; its advantage is the ability to assess the localization of the pulse. For a modified scalogram, the advantage is the estimation of the signal periodicity, and the disadvantage is the inaccuracy in determining the range of pulse localization. For spectrum analysis in Mathematica, it is recommended to use a combination of two approaches (using a standard built-in function to determine the localization of the pulse) and a modified scalogram (to determine the periods of the constituent components).

The 21st century aviation and aerospace technologies have evolved and become more complex and technical. Turbofan jet engines as well as their cousins, the rocket engines (liquid/solid) have gone through several design upgrades and enhancements during the course of their design and exploitation. These technological upgrades have made engines very complex and expensive machines which need constant monitoring during their working phase. As the demand and use of such engines is growing steadily, both in the civilian and military sectors, it becomes necessary to monitor and predict the behavior of parametric data generated by these complex engines during their working phases. In this paper flight parameters such as Exhaust Gas Temperature (EGT), Engine Fan Speeds (N1 and N2), Fuel Flow (FF), Oil Temperature (OT), Oil Pressure (OP), Vibration and others where used to determine engine fault. All turbo fan engines go through several distinctly different working phases: Take-off phase, Cruise phase and Landing phase. Recording generated parametric data during these different phases leads to a massive amount of in-flight data and maintenance reports, which makes the task of designing and developing a fault diagnostic system highly challenging. It becomes imperative to use modern techniques in data analysis that can handle large volumes of generated data and provide clear visual results for determining the technical status of the engine under investigation/monitoring. These modern techniques should be able to give clear and objective assessment of the object under investigation. Cluster analysis methods based on Neural Networks such as c-means, k-means, self-organizing maps and DBSCAN algorithm have been used to build clusters. Differences in cluster groupings/patterns between healthy engine and engine with degraded performance are compared and used as the bases for defining faults. Fault diagnosis plays a crucial role in aircraft engine management. Timely and accurate detection of faults is the foundation on which maintenance turnaround times, operational costs and flight safety are based. The data used in this paper for analysis was obtained from flight data recorder during one flight cycle. The final decision on a fault is taken by an engineer.

The paper investigates the problems of reduction (decomposition) of multidimensional data models in the form of hypercube OLAP structures. OLAP data processing does not allow changes in the dimension of space. With the increase in data volumes, the productivity of computing cubic structures decreases. Methods for reducing large data cubes to sub-cubes with smaller volumes can solve the problem of reducing computing performance.The reduction problems are considered for cases when the cube lattice has already determined criteria aggregation, and the cube decomposition into smaller cubes is needed to reduce the computation time of the full lattice when dynamically changing data in the cube.The objective of the paper is to find conditions for reducing the computational complexity of solving data analysis problems by reduction methods, to obtain exact quantitative boundaries for reducing the complexity of decomposition methods from the class of polynomial degrees of complexity, to establish the nature of the dependence of computational performance on the structural properties of a hypercube, and to determine the quantitative boundaries of computational performance for solving decomposition problems of data aggregation .The study of the computational complexity of decomposition methods for the analysis of multidimensional hyper-cubes of polynomial-logarithmic and polynomial degrees of complexity is carried out. An exact upper limit is found for reducing the complexity of decomposition methods for analyzing the initial OLAP - data hypercube with respect to non-decomposition ones and based on them criteria are proved for the effective application of reduction methods for analyzing hypercube structures in comparison with traditional non-reduction methods.Examples of decomposition methods of cube structures are presented, both reducing and increasing computational complexity in comparison with calculations using the full model.The results obtained can be used in processing and analysis of information arrays of hypercube structures of analytical OLAP-systems belonging to the BigData class, or ultra-large computer multidimensional data systems.

At present, multilateration systems are becoming increasingly important in air traffic control. This is due to their significant advantages in compare with secondary surveillance radar complexes. This article solves the problem of synthesizing an algorithm for object location estimation for multilateration system operating in passive mode. The synthesized algorithm is a combination of a procedure, the result of which is a rough estimate of the observed object coordinates, and an iterative algorithm specifying the resulting solution. The rough estimate is the result of solving a linear system of equations. The iterative refinement procedure is based on the linearization of the observational equations and does not require a large number of iterations. The paper provides a comparative statistical analysis of the proposed algorithm and the known Bancroft algorithm. For an objective analysis of two algorithms, the paper derives the Cramer-Rao boundary for the correlation matrix of estimates of the observed object coordinates, which makes it possible to determine the potential accuracy of the solution of the problem. It is shown that both algorithms allow obtaining estimates, the accuracy of which is close to the potentially achievable accuracy of the object location estimate. In contrast to the Bancroft algorithm, the rough estimate of the object location is unambiguous. This virtue reduces the total amount of computations during the algorithm implementation and reduces the probability of anomalous errors.

International audience; The paper deals with the problem of identification of linearly varying frequency of sinusoidal signal with unknown amplitude and phase. Identification task for linearly varying frequency occurs, for example, during telescope operation control and it is of practical interest. Existing synthesis methods for identification algorithms of linearly varying frequency of sinusoidal signal use unlimited functions of time that is not attractive from a technical point of view, since the measurement noise multiplied by an unlimited function tends to give extremely poor estimates of the tunable parameter. This paper proposes a new approach for identification of linearly varying frequency comprising iterative filtering of measured sinusoidal signal (with the use of linear first order stable components), which in turn gives the possibility to obtain a simple linear regression model with one unknown constant parameter. We present computer simulation results, illustrating the performance of the proposed identification algorithm. Computer modeling was performed both in the presence and absence of the measurement noise. Also, comparative analysis of the proposed approach with the previously obtained methods was carried out within the framework of computer simulation. It was shown that the presented solution provides a significant improvement in the accuracy of an unknown frequency identification in the noise presence.; Рассмотрена задача идентификации линейно меняющейся частоты синусоидального сигнала, имеющего неизвестные амплитуду и фазу, возникающая, например, при управлении телескопом. Традиционно методы синтеза алгоритмов идентификации линейно меняющейся частоты синусоидального сигнала используют неограниченные функции времени, что вызывает технические проблемы, поскольку в этом случае наличие шумов при измерении может существенно исказить настраиваемый параметр. Предложен подход к идентификации линейно меняющейся частоты, предусматривающий итеративную фильтрацию (с использованием линейных устойчивых звеньев первого порядка) измеряемого синусоидального сигнала, которая позволяет получить простую линейную регрессионную модель с одним неизвестным постоянным параметром. Приведены результаты компьютерного моделирования, иллюстрирующие работоспособность представленного алгоритма идентификации. Компьютерное моделирование выполнено как при наличии шумов в измерениях, так и в их отсутствие. Путем компьютерного моделирования проведен сравнительный анализ предлагаемого подхода с полученными ранее методами, и показано, что представленное решение обеспечивает существенное повышение точности идентификации неизвестной частоты при наличии шумов

Рассмотрена задача маршрутизации транспорта с ограничениями по временным окнам. Требовалось составить план доставки товара клиентам, построив маршруты движения идентичных транспортных средств так, чтобы общая длина пройденного пути была минимальной. Для решения задачи разработан гибридный алгоритм. Он состоит из методов построения исходных решений, муравьиного алгоритма и локального поиска. В муравьином алгоритме в процессе формирования маршрутов разрешается нарушение временных ограничений при условии добавления штрафа в целевую функцию. Предложенный метод показал высокую эффективность при решении задач кластерного типа и задач с долгосрочным горизонтом планирования., The purpose of this paper is to improve the performance of a hybrid method based on ant colony optimization (ACO) that finds approximate solutions of the vehicle routing problem with time windows (VRPTW). In order to solve this problem it is required to design a plan for goods delivery to the customers generating the routes of identical vehicles so that the total travelled distance is minimal. For the VRPTW solving, the hybrid method is developed in which a usage of trial solutions makes it possible to explore the most promising parts of the search space. The initial methods for solution construction, an ant colony optimization (ACO) algorithm and local search are proposed in the framework of the hybrid method. In the ACO algorithm, when generating the routes, it is allowed to violate the time window constraints. A method to restore the feasibility of solutions is implemented within the relaxation scheme under “returns in time” principle. Numerical results for solving all problems with 25, 50 and 100 customers from the Solomon test set are obtained. We provide the results on the time and deviation of the solution of these problems in comparison with the results of other authors. Some problems and their classes were solved much faster by the algorithm proposed in this paper. Relative deviations from optimal values of the objective function for the most complex tasks decrease with increasing decision time. The proposed approach can be considered to be an additional or an alternative algorithm for solving the cluster type and the long-term planning horizon problems of the VRPTW., №5(23) (2018)

The paper describes a distributed algorithm and a structure of the software package for its implementation in which a program for computing the vehicle launch dynamics under interaction with the medium flow is complemented with a program to determine the unsteady hydrodynamic loads by the vortex element method.A distinctive feature of the developed system is that its local (running on a single computing core) LEAVING program to calculate the launch dynamics runs together with concurrent (running on multiple computing cores) MDVDD program to compute the unsteady vortex flow and hydrodynamic loads. The LEAVING program is the main one. It is launched app and then runs the MDVDD program in concurrent mode on the specified number of cores. Using MPI technology allows you to use a multiprocessor PC or a local network of multiple PCs to perform calculations. The equations of launcher spring-mass model dynamics and equations of vortex elements parameters evolution are integrated with the same time step. The interprogram communiaction in the step is provided asynchronously using the OS Windows Event mechanism (Events). Interfacing between LEAVING and MDVDD programs is built using the OS Windows FileMapping technology, which allows a specified data structure to be displayed and read to the fixed memory area.The paper provides analysis of acceleration achieved with parallel processing on different numbers of cores, and defines a parallelization degree of various operations. It shows that the parallelization efficiency of the developed algorithm is slower than in case of calculation of the rigid body flow. The causes of reduced efficiency are discussed.It is shown that the developed algorithm can be effectively used to solve problems on a small number of cores, e.g. on PC based on one or two quad-core processors.

To build mathematical models of actuating mechanisms (AM) of robots with linear kinematic structure, J. Denavit and R.S. Hartenberg (D-H) proposed to use a special coordinate system (CS). It uses a matrix of homogeneous transformation and provides clear and unambiguous rules to build mathematical models of robot actuating mechanisms. Developers widely use this approach because of its clarity and binding to AM design parameters. However, its use to describe robots the AM of which has a spatial tree-like kinematic structure revealed the certain hardship.The paper offers a method for building a modified D-H coordinate system. Its using allows to create mathematical models of robot AM, having spatial kinematic structure. The method is based on using both the graphs theory and the known D-H coordinate system jointly.The paper defines concepts of main and auxiliary coordinate systems and the order of their location on the tree-like AM. The values of the modified parameters of D-H are obtained. There its known parameters are complemented by parameters f(i), which determine the father number of the link i, and ns(i), that shows, which son in succession is the link i for the link f(i). An algorithm to form the matrix of reachability and the graph of reachability of the tree-like AM is proposed.It is proved that the use of the modified D-H coordinate system allows us to record in a block-matrix form both kinematic and dynamic equations for all links of the tree-like AM of robot. The use of these equations together with D'Alembert principle allowed us to write the equations of the tree-like AM dynamics of robot in the form traditional for recording the AM dynamics equations with open kinematic structure.Via examples of mathematically described kinematics and dynamics of tree-like AM of specific robots (robot-dog, robot-crab, anthropomorphic walking robot, etc.) the paper shows efficiency of modified D-H coordinate system.Obtained research results of the medical robot AM have shown that the proposed model can be successfully used to describe robots with linear open kinematic structure, which is a special case of tree-like kinematic one.

Шинкарев Александр Андреевич, инженер-программист, ООО «741 Студиос.ру», г. Екатеринбург; sania.kill@mail.ru. A.A. Shinkarev, sania.kill@mail.ru “741 Studios.ru” LLC, Ekaterinburg, Russian Federation This paper describes continuation of the authors’ work in the field of traffic flow mathematical models based on the cellular automata theory. The refactored representation of the multifactorial traffic flow model based on the cellular automata theory is used for a representation of an adaptive deceleration step implementation. The adaptive deceleration step in the case of a leader deceleration allows slowing down smoothly but not instantly. Concepts of the number of time steps without conflicts and deceleration aggressiveness coefficient are introduced. Also in this paper a new step type for models based on the cellular automata is formulated on the example of a stop signal. The new step type unites notification and signalization steps. The new step type extends the concept of the three-stepped unified representation of the traffic flow models based on the cellular automata that was formulated in the previous authors’ work. Рассмотрено продолжение работы автора в области математических моделей транспортных потоков на основе теории клеточных автоматов. На примере переработанного представления многофакторной модели транспортных потоков на основе теории клеточных автоматов представлена реализация шага адаптивного торможения, который в случае торможения впереди едущего транспортного средства позволяет снижать скорость плавно, а не мгновенно. Введены понятия количества тактов без конфликта и коэффициента агрессивности торможения. Также в статье на примере стоп-сигнала сформулирован новый тип шагов для моделей на основе клеточного автомата, который объединяет шаги оповещения и сигнализации. Новый тип шагов расширяет концепцию трёхступенчатого унифицированного представления математических моделей транспортных потоков на основе клеточного автомата, которая была сформулирована в предыдущей работе автора.

Error detection codes are mechanisms that enable robust delivery of data in unreliable communication channels and devices. Unreliable channels and devices are error-prone objects. Respectively, error detection codes allow detecting such errors. There are two classes of error detecting codes - classical codes and security-oriented codes. The classical codes have high percentage of detected errors; however, they have a high probability to miss an error in algebraic manipulation. In order, security-oriented codes are codes with a small Hamming distance and high protection to algebraic manipulation. The probability of error masking is a fundamental parameter of security-oriented codes. A detailed study of this parameter allows analyzing the behavior of the error-correcting code in the case of error injection in the encoding device. In order, the complexity of the encoding function plays an important role in the security-oriented codes. Encoding functions with less computational complexity and a low probability of masking are the best protection of encoding device against malicious acts. This paper investigates the influence of encoding function complexity on the error masking probability distribution. It will be shownthat the more complex encoding function reduces the maximum of error masking probability. It is also shown in the paper that increasing of the function complexity changes the error masking probability distribution. In particular, increasing of computational complexity decreases the difference between the maximum and average value of the error masking probability. Our resultshave shown that functions with greater complexity have smoothed maximums of error masking probability, which significantly complicates the analysis of error-correcting code by attacker. As a result, in case of complex encoding function the probability of the algebraic manipulation is reduced. The paper discusses an approach how to measure the error masking probability in the case of nonuniform distribution of the input code words. This approach can also be used to study the characteristics of security-oriented codes in case of strong and weak models of algebraic manipulation.

Introduction. With the development of digital technology more attention is paid to making radio-receiving tracks based on SDR technology (Software Defined Radio), which is based on the processing of digitalized radio-frequency signals exclusively by means of software in real time. Moreover the construction ofdata-acquisition systems on one integral chip (SoC) is widely used right now. The main fundamental basis of SoC systems is the FieldProgrammable Gate Array (FPGA). One important step of receiving of radio-frequency signals is a digital down conversion, followed by filtration and repeated decimation. Since processing in DDC is made in a fixed calculation format, than before the immediate implementation of this structure on FPGA, it is necessary to analyze the effect offixed calculation bits on the quality of signal processing. Later it can be used to choose DDC internal calculation bits without sacrificing the set quality of signal processing and hardware resources on its implementation. In the well-known papers, analysis of the effect of signal quantization is reduced to two methods: deterministic and probability methods. Deterministic method gives the top-ofthe-line evaluation of quantizing noise at the output of digital system. Probability method is based on evaluation of quantizing noise dispersion at the output of the device. Evaluation of the signal and the quantization noise in the SDDC based on their PSD. In this section, mathematical expressions were obtained for the construction of PSD signal and the quantizing noise at the output of each of the subsystems of the digital DDC. Criterion for selecting SDDC bit is the relative level of PSD quantizing noise at the output of the digital system. Since the ADC is fixed, the choice of bit computing in SDDC should be such that the total quantizing noise in SDDC would not exceed the ADC quantizing noise at the output of the digital system. Example calculation and construction of PSD signal and quantization noise in Matlab for reception QPSK-signal. In this part of the article an example of the analysis of DDC structure for receiving QPSK- signal was considered. Mathematical Matlab's model has been developed which allows to calculate the PSD of the signal and the quantization noise depending on the internal structure of the SDDC bit based on the formulas of section 2 this paper. These expressions make it possible to construct a PSD noise separately from each SDDC source output, and separately estimate the contribution of each source of quantizing noise to the total noise at the output of the digital system. From these results a decision on the choice of a particular quantization step that depends on the selected calculating bit at each stage of processing was made. Conclusions. Quantizing noise dispersion is not an adequate quality evaluation of processing in multi-stage and multi-rate systems, which include software DDC under review. In such systems the sequential changes of the line, as well as the nature of the spectrum of interfering components, including quantization noise, happen. Therefore in this paper I propose a different approach based on the calculation of the power spectral density (PSD) of the quantizing noise at the output of the device, taking into account the filtering effect of all of its stages and repeated decimation., В данной работе предложен метод анализа влияния шумов квантования на обработку сигнала в цифровом DDC, который основанный на вычислении спектральной плотности мощности (СПМ) шумов квантования по выходу устройства с учетом фильтрующего действия всех его каскадов и многократной децимации. В работе были получены математические выражения для нахождения СПМ сигнала и шумов квантования на выходе каждой из подсистем цифрового DDC. Данные выражения дают возможность выбрать внутренние разрядности вычислений в SDDC таким образом, чтобы суммарный шум квантования в данном устройстве не превышал бы шум квантования АЦП на выходе ЦС. В среде Matlab приведен пример анализа DDC для приема QPSK сигнала., В даній роботі запропоновано метод аналізу впливу шумів квантування на обробку сигналу в цифровому DDC, який ґрунтується на обчисленні спектральної щільності потужності (СЩП) шумів квантування на виході пристрою з урахуванням фільтруючої дії всіх його каскадів і багаторазової децимації. У роботі були отримані математичні вирази для знаходження СЩП сигналу і шумів квантування на виході кожної з підсистем цифрового DDC. Дані вирази дають можливість вибрати внутрішні розрядності обчислень в SDDC таким чином, щоб сумарний шум квантування в цьому пристрої не перевищував би шум квантування АЦП на виході ЦС. У середовищі Matlab наведено приклад аналізу DDC для прийому QPSK сигналу.

The paper considers a digital image processing method that provides efficient transmission, redistribution and storage of aerospace environmental monitoring videographic information. The requirement to increase the monitoring efficiency, if necessary, to carry out regular monitoring of changes in the image field of the observed object is especially relevant when describing spatially aligned sets of images obtained after multi-zone, multi-time and multi-polarization shooting. In many remote sensing applications, the processing efficiency reflects the degree of reduction in the volume of transmitted, described, analyzed and stored videographic information. The computational processing of digital images based on the coordinate survey scheme is presented. The method can be used to perform the procedure for decoding images in order to solve the problem of classifying objects of interest, analyzing images. Such characteristics of binary objects as a spatial boundary and a contour were used as deciphering signs. These features make it possible to describe the shape of an object, its geometric parameters and search for images with specific spatial structures. The processing method is realized by executing efficient algorithms for coding an image on a discrete grid by means of a chain code and spectral coding based on the fast discrete Hartley transform. The result of processing comes down to minimizing the number of such basic computational operations as multiplication, addition, transferring, as well as reducing the time and capacitive complexity of the program, and reducing the redundancy of the initial data. An example of an effective representation and description of a segmented image of an object is given. The proposed method makes it possible to expand the technical capabilities of more efficient transmission and processing of images for solving problems in the field of remote sensing.

Introduction. In all types of digital communication, error control coding techniques are used. Many digital communication standards, such as Wi-Fi and 5G, use low density parity check (LDPC) codes. These codes are popular because they provide building encoders and decoders with low computational complexity. This work objective is to increase the error correcting capability of the well-known bit-flipping decoder (BF) of LDPC-codes. For this purpose, a modification of the decoder is built, which enables to dynamically control one of its main parameters whose choice affects significantly the quality of decoding. Materials and Methods. The well-known bit-flipping decoder of binary LDPC-codes is considered. This decoder has several parameters that are not rigidly bound with the code parameters. The dependence of the decoding quality on the selection of the output parameters of the bit-flipping decoder was investigated through simulation modeling. It is shown that the decoding results in this case are significantly affected by the input parameter of the decoder — threshold T. A modification of the BF-decoder of binary LDPC-codes has been developed, in which it is proposed to set the threshold dynamically during the execution of the algorithm depending on the error rate. A comparative analysis of the error- correcting capability of decoders is carried out by the simulation modeling method. Results. A lemma on the maximum value of the decoder threshold T is formulated and proved. Upper bounds for the number of operations are found for the original and modified decoders. A simulation model that implements a digital noise-immune communication channel has been built. In the model, the initial data is encoded with a given LDPC-code, then it is made noisy by additive uniformly distributed errors, and thereafter, it is decoded in turn by the bit-flipping algorithm with different threshold T parameters, as well as by a modified decoder. Based on the input and output data, the correction capacity of the decoders used is estimated. Experiments have shown that the error-correcting capability of the modified decoder in the range of the real error rate is higher than that of the original decoder, regardless of the selection of its parameters. Discussion and Conclusions. The lemma, proved in the paper, sets the upper bound on the threshold value in the original decoder, which simplifies its adjustment. The developed modification of the decoder has a better error- correcting capability compared to the original decoder. Nevertheless, the complexity of the modification is slightly increased compared to the original algorithm. It has been pointed out that the decoding quality of a modified decoder develops with a decrease in the number of cycles in the Tanner graph and an increase in the length of the code.

Theaimof the article is to clarify the basics of the digitalization strategy of the competitive businesses and identify features of the institutional environment that ensure the development of cryptocurrency as a new asset (IT product) of the modern economy, analyze the methods of implementing the cryptocurrency business models. Therelevanceof the research paper is determined by the need to develop a competitive Russian cryptocurrency (including the cryptoruble) with the growing private, state and cross-national cryptocurrencies. Thescientific noveltyof the study implies clarifying the informal and formal rules of the institutional environment and related methods ensuring the development of a competitive cryptocurrency. The authors consider the followingmethodsto implement the institutional features of the cryptocurrencies business model development: logic and blockchain algorithm that establish trust and collaboration between cryptocurrency developers; logic and blockchain consensus algorithm ensuring that all the parties of the blockchain network come to a common agreement (consensus); logic and blockchain algorithms that form cryptocurrency transactions and control its turnover by generating blocks of cryptocurrencies, by forming the structure of blocks and transactions of cryptocurrencies, by storing cryptocurrencies’ keys and providing security, by mining (forging) cryptocurrency, etс.Theresultsof the study provide a basis for identifying the institutional features and the corresponding methods providing a competitive cryptocurrency development with a detailed analysis of the blockchain consensus algorithms that ensure the competitiveness of the cryptocurrency. Theconclusionsshow that the most promising are the hybrid consensus algorithms which may include both the logic of two or more known algorithms and the original logic of a new algorithm. The authorsrecommenddefining the logic of the blockchain consensus algorithm as a priority when developing a cryptocurrency to ensure reliability of the transactions in the blockchain network, thus increasing the competitiveness of the cryptocurrency.

The aim of the work is to comparatively evaluate the sizes of FIFO and LIFO stacks required for image segmentation based on growing regions. The coordinates (y, x) of the pixels that need to be attached to the cultivated area are placed in stacks during the segmentation process. The size of the stack needed to store the coordinates depends on the structure of the image and cannot be determined before segmentation. To avoid stack overflow, its size is determined for maximum load conditions when the image contains a single maximum area. In this case, the stack size is equal to the image size. This approach does not take into account the process of stack unloading and leads to memory overrun. Expressions are obtained in the paper that allow one to increase the accuracy of determining the sizes of FIFO and LIFO stacks necessary for storing the coordinates of adjacent pixels in a segmentation algorithm based on growing regions under maximum load conditions. In this case, the initial position of the region growth point and the direction of the selection of adjacent pixels in the scanning window are taken into account. A comparative assessment of the stack sizes required for image segmentation showed that using the FIFO stack is preferable to the LIFO stack and leads to significant memory savings.

Introduction. A hardware basis of modern Advanced Driver Assistance Systems (ADAS) consists of millimeterrange radars, characterized by a relatively short range (meters – tens of meters). At the same time, improving of traffic safety requires to increase the range at least to several hundred meters. The one way to achieve such values is to increase wavelength of a probing signal, to use the centimeter range of wavelengths, for example. The paper represents a detailed description of main steps of signal processing algorithm in the model of the ADAS low-power centimeter range radar, which provides fast-moving objects speed and range definition.Aim. Development of an algorithm for estimating the range and the speed of targets by an autocorrelation radar with a wide-band continuous linear frequency modulation (linear FM) signal in order to increase the rate of the ADAS system estimates formation.Materials and methods. The proposed algorithm is based on the methods of primary and secondary digital processing of radar signals. The model of a centimeter-range autocorrelation radar with a broadband continuous linear FM probing signal was used for practical researches. MATLAB software was used to process the received signal samples.Results. The algorithm has been developed to determine the speed and the range of fast-moving objects in conditions when their movement during the evaluation interval significantly exceeds the radar range resolution. The use of simplified Kalman filtering for inter-period secondary signal processing allowed to increase significantly the stability of the algorithm. In a full-scale experiment using the low-power radar model with continuous radiation of the centimeter range, it was shown that a stable assessment of a real car speed and range was provided at a distance of at least about one kilometer.Conclusion. The results of the field experiment make it possible to draw conclusions that the proposed algorithm is highly robust even in the absence of inter-period secondary processing. Its usage allows one to improve the stability of the algorithm without considerable additional computational costs. It is possible because near-linear dynamics of the observation object and of the radar carrier makes it sufficient to use a simplified implementation of Kalman filter in the form α-β-algorithm.

This paper considers the problem of memory allocation for the organization of the LIFO-stack in the algorithm for image segmentation based on growing regions is considered. Segmentation divides the image into regions with identical or similar properties and is the most demanding process for the capacity of RAM. The cultivation of areas begins with the neighborhoods of pre-selected initial growth pixels and uses stacks to store the coordinates of adjacent pixels attached to the cultivated region. Stack loading is maximized when the segment size matches the size of the YX image. In the absence of an expression for the exact determination of the size of the stack, it is possible to guarantee the stable operation of the algorithm for growing regions, eliminating the overflow of the memory allocated for processing if the stack size is assumed equal to YX. However, this approach does not take into account the fact that filling the coordinate stacks is also accompanied by a selection of them, which makesthe stack size always smaller than YX. The article proposes an expression that allows one to increase the accuracy of determining the required size of the LIFO-stack for storing the coordinates of adjacent pixels depending on the image size. The expression takes into account the conditions of the maximum load of the LIFO-stack when: a) the segmentation of the square region with the initial growth pixel in the corner of this region is carried out; b) in the scan window, adjacent pixels are always selected in order with the first selectable pixel located in the corner of the scan window. Using the proposed expression to calculate the required capacity of the LIFO-stack under conditions of its maximum load in the image segmentation algorithm based on growing regions provides a 2-fold reduction in the number of LIFO-stack memory cells.

The paper contains a new text searching method representing modification of the Boyer-Moore algorithm and enabling a user to find the places in the text where the given substring occurs maybe with possible errors, that is the string in text and a query may not coincide but nevertheless are identical. The idea consists in division of the searching process in two phases: at the first phase a fuzzy variant of the Boyer–Moore algorithm is performed; at the second phase the Dice metrics is used. The advantage of suggested technique in comparison with the known methods using the fixed value of the mistakes number is that it 1) does not perform precomputation of the auxiliary table of the sizes comparable to the original text sizes and 2) it more flexibly catches the semantics of the erroneous text substrings even for a big number of mistakes. This circumstance extends possibilities of the Boyer–Moore method by addmitting a bigger amount of possible mistakes in text and preserving text semantics. The suggested method provides also more accurate regulation of the upper boundary for the text mistakes which differs it from the known methods with fixed value of the maximum number of mistakes not depending on the text sizes. Moreover, this upper boundary is defined as Levenshtein distance not suitable for evaluating a relevance of the founded text and a query, while the Dice metrics provides such a relevance. In fact, if maximum Levenshtein distanse is 3 then how one can judge if this value is big or small to provide relevance of the search results. Consequently, the suggested method is more flexible, enables one to find relevant answers even in case of a big number of mistakes in text. The efficiency of the suggested method in the worst case is O(nc) with constant c defining the biggest allowable number of mistakes.

The active development of the mobile platforms sector such as smartphones, smart watches, fitness bracelets and other wearable electronic devices in the last 4 years has caused a huge growth of the market of mobile applications-services. Western countries are actively implementing mobile applications-services for household energy users. In Belarus, there is a positive dynamics in the number of active users of applications-services, every year it is possible to attract 7 % of unique customers. In the present paper the experience of implementation and operation of the mobile application for power systems is analyzed. The dynamics of the market of mobile applications-services has been traced: the amount of time spent by the person in interaction with the device was determined as well as the total expenditure of funds in the application at the moment; also, the growth of expenses within the applications was forecasted. The potential benefits for business and end-users of services from the implementation of mobile applications-services were demonstrated. Their properties, main qualities and advantages over traditional methods of “business – client” interaction are considered. A number of features needed for the successful functioning of the mobile application in the power system of Belarus are identified. The process of creating software for smart devices has been studied and the functionality needed by the mobile application for the power system has been proposed for attracting new users. A special algorithm for the launch and successful “life cycle” of a mobile application has been proposed. It allows to operate and develop mobile applications-services as efficiently as possible, as well as to avoid the most common errors at the stages of their development and launch. The implementation of a mobile application in the power system of the Republic of Belarus, in the long-term, will significantly increase customer loyalty, simplify interaction with users, make it possible to build new models of distribution of electricity, and, consequently, regulate the demand for energy resources.

Load profile alignment based on optimal power consumption management is considered to be one of the main ways to ensure efficient operation of energy systems in the short-term planning. Alignment load profile with a view to reducing costs can be implemented with the aid of consumers’ involvement by administrative and economic measures. Administrative measures are associated with the forced restriction of consumer loads in certain intervals of the planning period. On one hand, these measures provide benefits to the power system by alignment load profile, and on the other hand, they cause detriment to consumers. Ultimately, in some cases, for the whole power system, the detriment may be greater than the benefits. Therefore, it is advisable to use administrative measures in conditions of shortage of power and electricity in the power system. Optimal planning of short-term regimes of power systems according to rigid load profile received after alignment can be carried out by traditional methods. The solution of such a problem ought to be initially carried out under conditions of non-rigid load profile resulting from the directive use of administrative and economic measures carried out with the help of specially developed models. In this regard, the paper proposes a mathematical model of the problem of optimizing load profile of regulated electricity consumers to be used for optimal planning of shortterm power system modes, an algorithm for optimal planning of a short-term power system mode with optimizing load profile of regulated power consumers. Also, algorithms are proposed for accounting for simple and functional constraints in the form of equalities and inequalities when optimizing load profile. The effectiveness of the described algorithm for optimizing the short-term mode of the power system, taking into account the optimal load control of adjustable electricity consumers, has been studied using the example of optimal coverage of the load profile of power system, which contains two consumers with adjustable load profile, and two TPPs. Based on the calculated-and-experimental studies, it was determined that the proposed mathematical model of the problem is adequate, while the developed algorithms for optimal planning of short-term power system modes with optimization of load profile of regulated electricity consumers and taking into account various types of limitations are of high computational qualities.

The implementation of the WaldBoost algorithm is considered, and its modification is proposed, which allows to significantly reduce the number of weak classifiers to achieve a given classification accuracy. The efficiency of the proposed algorithm is shown by specific examples. The paper studies modifications of compositions (ensembles) of algorithms for solving real-time pattern recognition problems. The aim of the study is to improve the known machine learning algorithms for pattern recognition using a minimum amount of time (the minimum number of used classifiers) and with a given accuracy of the results. We consider the implementation of the WaldBoost algorithm, which combines two algorithms: adaptive boosting of weak classifiers – AdaBoost (adaptive boosting), which has a high generalizing ability, and the sequential probability ratio test – SPRT (Wald test), which is the optimal rule of decision-making when distinguishing two hypotheses. It is noted that when using the WaldBoost, the values of the actual probability of classification errors, as a rule, are less than given because of the approximate boundaries of the SPRT, so that the classification process uses an excessive series of weak classifiers. In this regard, we propose a modification of the WaldBoost based on iterative refinement of the decision boundaries, which can significantly reduce the number of used weak classifiers required for pattern recognition with a given accuracy. The efficiency of the proposed algorithm is shown by specific examples. The results are confirmed by statistical modeling on several data sets. It is noted that the results can be applied in the refinement of other cascade classification algorithms.

В работе представлены три итерационных алгоритма быстрого преобразования Фурье с прореживанием по времени, имеющие алгоритмическую сложность O (N·R·log2N), где R — частотное разрешение спектральной характеристики (отношение длины набора частот к длине N набора отсчетов исходного сигнала). Алгоритмы отличаются способами организации вычислений: некоторые используют обратную перестановку битов, другие — дополнительные массивы. Приведены подробные вычислительные графы, а также блок-схемы разработанных алгоритмов. Полученные результаты можно использовать для улучшения отечественной электроники и программного обеспечения, а также включать в учебный процесс при подготовке инженеров в области цифровой обработки сигналов., This paper presents three iterative algorithms for fast Fourier transform with decimation in time; these algorithms have the algorithmic complexity O (N·R·log2N), where R is the frequency resolution of the spectral characteristic (the ratio of the length of the frequency set to the length of the N set of samples of the source signal). The algorithms differ in the way they organize calculations: some use reverse bit permutation, while the others use additional arrays. Detailed computational graphs and flowcharts of the developed algorithms are provided. The results obtained can be used to improve domestic electronics and software as well as may be included in the training process for engineers in the field of digital signal processing., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 2 2021

Рассматривается синтез оптимального алгоритма обнаружения сигнала от реальной цели со стабильным отражателем, плотность распределения вероятностей амплитуды которого подчиняется обобщенной плотности распределения Рэлея., The paper deals with the synthesis of an optimal algorithm for detecting a signal reflected by a target with a stable scatterer, whose amplitude probability density assumes to be the generalized Rayleigh distribution law., №03(4.3) (2020)

Предлагаются алгоритм и построенная на его основе программа оценки эффективного кодирования источника сигналов при их преобразованиях в различных метрических пространствах (в частности, для широко используемого в настоящее время аналого-цифрового преобразования непрерывного сигнала в двоичный). Алгоритм оценки учитывает показатели искажений при кодировании двоичным кодом,вероятности появления этих искажений при передаче элементов сообщения и вероятности появления сообщения в канале связи. Помимо самого алгоритма, предложены его программная реализация, созданная с помощью языка программирования 0#,а также усовершенствованный интерфейс на базе MS Excel. В программной реализации имеется графическая среда для пользователя., This paper proposes an algorithm and a program built on its basis for evaluating the effective coding of a signal source during their transformations in various metric spaces, and, in particular, for the currently widely used analog-to-digital conversion of a continuous signal to a binary signal. The estimation algorithm takes into account the indicators of distortions under binary coding, the probability of occurrence of these distortions when transmitting message elements, and the probability of a message appearing in the communication channel. In addition to the algorithm itself, its software implementation, created using the C# programming language, and an improved interface based on MS Excel are proposed. Software implementation has a graphical user environment., Труды НИИР, Выпуск 4 (3) 2020

Математические модели многих технических систем имеют вид интегрального уравнения Вольтерра I рода с разностным ядром. Для таких систем задача идентификации заключается в построении оценки для импульсной переходной функции системы по измеренным (с шумами) значениям входного и выходного сигналов и является некорректно поставленной. В недавней работе авторов предложен устойчивый алгоритм идентификации, использующий аппарат сглаживающих кубических сплайнов для вычисления первых производных входного и выходного сигналов. К сожалению, сглаживающие кубические сплайны неудовлетворительно фильтруют аномальные измерения. Поэтому предложен двухшаговый алгоритм идентификации, на первом шаге которого аномальные измерения удаляются с использованием пространственно-локального фильтра, а затем строятся сглаживающие сплайны, Volterra integral equation of the first kind often represents stationary dynamic systems. For such a model, the non-parametric identification problem reduces to the estimation of pulse transition characteristics (that is the kernel of integral equation) from the registered noise-contaminated values of input and output signals. To formulate stable solution for identification problem authors propose algorithm that estimates pulse transition characteristics by solving Volterra integral equation of the second kind and involving first derivatives of input and output signals application that corresponds to non-stable problem. Smoothing cubic splines employed in robust calculation of first derivatives allow finding a stable solution of identification problem even when input and output signals of system identified are essentially noise-contaminated. Unfortunately, measured values of input and output signals also contain anomalous measurements such as pulse noises, glitches, etc. Such measurements are poorly smoothable by splines that cause high levels of first derivatives errors and, conversely, significant pulse transition characteristics identification errors of dynamic system. For all the reasons aforementioned, in this paper authors present the new stable two-step identification algorithm in case of anomalous measurements. The first step of the algorithm is for non-linear local-spatial combined filtration procedure of input and output signals that helps to effectively remove anomalous measurements. At the second step, smoothing cubic splines are used to calculate stable first derivatives of previously filtered signals. An extensive computational experiment showed the effectiveness of the proposed algorithm, which allows solving the identification problem with acceptable accuracy in practice even at high intensity of anomalous measurements. The experimental results give reason to recommend this algorithm for solving practical problems of identifying stationary systems, the mathematical model of which is the Voltaire integral equation of the first kind with a difference kernel, Вычислительные технологии, Выпуск 3 2020

В статье публикуется белокаменный блок из церкви Рождества Богородицы в Боголюбове, найденный Н. Н. Ворониным во время раскопок 1930-х гг. и находящийся сейчас внутри здания в экспонированном раскопе. Профиль этого блока находит себе аналогии в профилях окон в апсидах церкви Покрова на Нерли. Эти профилировки восходят к обработке окон собора в Модене, построенного на рубеже XI–XII вв. архитектором Ланфранко и скульптором Вильгельмо в романском стиле. В результате атрибуции каменного блока как оконного и подбора аналогий становится ясно, что храм в Боголюбове имел окна, похожие на окна алтаря в церкви Покрова на Нерли, и что мастера, строившие оба памятника по заказу князя Андрея Боголюбского, происходили из итальянской области Эмилия., The paper publishes a white stone block from the Church of the Nativity of Our Lady discovered by N. N. Voronin during excavations in the 1930s. The block is now on display in an exhibition trench inside the building. There are analogies to this block profile among the profiles of the windows in the apses of the Church of the Intercession on the Nerl’. These profiles are modeled after window profiles of a cathedral built in Modenaat the turn of the 12th century by the architect Lanfranco and the sculptor Wiligelmo in the Romanesque style. The attribution of the stone block as a window unit and the selected analogies mean that the cathedral in Bogolyubovo had windows similar to the altar windows in the Church of the Intercession on the Nerl’ and that the masters who built both churches commissioned by the Prince Andrey of Bolgolyubovo came from the Emilia Province in Italy., Краткие сообщения Института археологии (КСИА), Выпуск 259 2020

Одни из наиболее важных вычислительных задач разработка и адаптация итерационных методов для решения сверхбольших разреженных систем алгебраических уравнений. К таким вычислительным задачам приводит задача итерационной параллельной реконструкции трехмерных изображений промышленных изделий. Важно, что итерационные методы решения вычислительных задач большой размерности реализуются на параллельных структурах намного эффективнее, чем прямые методы их решения. В этой работе описан синхронный параллельный алгоритм, основанный на использовании системы MPI для решения задачи реконструкции трехмерных изображений промышленных изделий., Purpose. Currently, one of the most important tasks is the development and adaptation of iterative methods for solving ultra-large sparse systems of algebraic equations. Such computational problems are caused by the iterative parallel reconstruction of three-dimensional images of industrial products. It is important that iterative methods for solving computational problems of large size are implemented on parallel structures much more efficiently than direct methods for solving them. This paper describes a synchronous parallel algorithm based on the MPI system for solving the problem of reconstruction of three-dimensional images of industrial products. Methodology. It is important that iterative methods for solving computational problems of larger dimensionality on parallel structures are implemented more efficiently than the direct ones. Most algorithms based on direct solving methods have a significant hereditary sequential structure and require a large number of processors interactions which cannot be executed in parallel mode. Iterative methods, for the most part, require a significantly smaller number of interactions of this type and are relatively easily mapped onto parallel computational structures. Equally important, in most cases parallel implementations of classical iterative methods are more effective in terms of computational speed. The parallel execution of the algorithm is based on the distribution of the process in some way between various groups of processors. Depending on the interaction method between local processors, two different types of parallel iterative algorithms execution are distinguished: synchronous and asynchronous. In the former case, it is assumed that the processors complete the calculations and exchange all the necessary results before the start of a new iteration. The main disadvantage of synchronous parallel algorithms is that they require synchronization of iterations. This is a very difficult task, especially with large number of processors. In addition, the overall calculation speed is limited by the speed of the slowest processor. At the same time, faster processors spend most of their time in the waiting mode. But, nevertheless, the implementation of these parallel algorithms can be effectively achieved using the MPI standard. Findings. Synchronous parallel computing algorithms and program codes for threedimensional tomographic reconstruction in a conical beam were developed. Program code debugging and numerical calculations were performed on a hybrid cluster based on the OpenPOWER architecture using the MPI system. For designing a parallel threedimensional tomographic reconstruction, a voxel form of parallelism was used. Originality. Implemented parallel iterative technology of three-dimensional images reconstruction has undeniable advantages over traditional sequential iterative tomographic reconstruction. It allows reducing the time of tomographic reconstruction as many as tens of times, provides the ability to reconstruct products with sizes of 5123 to 10243 voxels with simultaneous storage of the submatrix node of the projection matrix in RAM, which eliminates the need for recalculation of matrix coefficients for each new iteration., №24 (2019)

Objectives. The aim of present paper is to minimise the errors in the approximation of experimentally obtained acceleration curves. Methods. Based on the features and disadvantages of the well-known Simoyu method for calculating transfer functions on the basis of acceleration curves, a modified version of the method is developed using the MathLab and MathCad software. This is based on minimising the sum of the squares of the experimental point deviations from the solution of the differential equation at the same points. Results. Methods for the implementation of parametric identification are analysed and the Simoyu method is chosen as the most effective. On the basis of the analysis of its advantages and disadvantages, a modified method is proposed that allows the structure and parameters of the transfer function to be identified according to the experimental acceleration curve, as well as the choice of optimal numerical values of those parameters obtained for minimising errors in the approximation of the experimentally obtained acceleration curves. Conclusion. The problem of optimal control over a complex technical facility was solved. On the basis of the modified Simoyu method, an algorithm for the automated selection of the optimal shape and calculation of transfer function parameters of dynamic elements of complex technical objects according to the acceleration curves in the impact channels was developed. This has allowed the calculation efficiency of the dynamic characteristics of control objects to be increased by minimising the approximation errors. The efficiency of the proposed calculation method is shown. Its simplicity makes it possible to apply to practical calculations, especially for use in the design of complex technical objects within the framework of the computer aided design system. The proposed method makes it possible to increase the accuracy of the approximation by at least 20%, which is an important advantage for its practical use.

The paper shows the general technology for designing a forest road route in space and the rationale for choosing the most effective method for specific conditions The experience of designing the track using the method of supporting elements showed its high efficiency, at the same time the opportunities for further improvement of the automated design process were revealed with the aim of completely eliminating the stage of graphic processing of the route and automatically recording all the requirements presented to it. To realize these possibilities, a study of the design of the clothoid route was carried out by approximating a sequence of points in the sketch line using nonlinear programming methods (abbreviated name is the method of approximation of a sequence of points). The idea is to determine the position and all the geometric characteristics of the clotoid path, corresponding to the requirements for it, by corresponding processing on the computer of the mathematical model of the sketch line. In this case, the trace should best approximate the specified sketch line, i.e. Geometrically incorrect approximate route. The sketch line can be obtained automatically, for example, using the method of designing the optimal "chain" route, or it can be scheduled by the designer using aerial photography materials or topographic plans, based on economic and other considerations, and entered into the computer's memory using automatic coordinate recorder.

Диссонанс является уточнением понятия аномальной подпоследовательности (существенно непохожей на остальные подпоследовательности) временного ряда. Задача поиска диссонанса встречается в широком спектре предметных областей, связанных с временными рядами: медицина, экономика, моделирование климата и др. В работе предложен новый параллельный алгоритм поиска диссонанса во временном ряде на платформе многоядерного ускорителя для случая, когда входные данные могут быть размещены в оперативной памяти. Алгоритм использует возможность независимого вычисления евклидовых расстояний между подпоследовательностями ряда. Алгоритм состоит из двух этапов: подготовка данных и поиск. На этапе подготовки выполняется построение вспомогательных матричных структур данных, обеспечивающих распараллеливание и векторизацию вычислений. На стадии поиска осуществляется нахождение диссонанса с помощью построенных структур данных. Выполнена реализация алгоритма для ускорителей архитектур Intel MIC (Many Integrated Core) и NVIDIA GPU, распараллеливание выполнено с помощью технологий программирования OpenMP и OpenAcc соответственно. Представлены результаты вычислительных экспериментов, подтверждающих масштабируемость разработанного алгоритма., Discord is a refinement of the concept of anomalous subsequence of a time series. The discord discovery problem frequently occurs in a wide range of application areas related to time series: medicine, economics, climate modeling, etc. In this paper we propose a new parallel discord discovery algorithm for many-core systems in the case when the input data fit in the main memory. The algorithm exploits the ability to independently calculate the Euclidean distances between the subsequences of the time series. Computations are paralleled using OpenMP and OpenAcc for the Intel MIC (Many Integrated Core) and NVIDIA GPU platforms, respectively. The algorithm consists of two stages, namely precomputations and discovery. At the precomputation stage, we construct the auxiliary matrix data structures to ensure the efficient vectorization of computations on an accelerator. At the discovery stage, the algorithm searches for a discord based on the constructed structures. A number of numerical experiments confirm a high scalability of the proposed algorithm., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 3 2019

AlgoWiki - это открытая энциклопедия свойств алгоритмов и их реализаций на различных программно-аппаратных платформах. Ее можно использовать для достижения различных целей, например для поиска оптимального алгоритма решения некоторой задачи, анализа информационной структуры приложения или для сравнения эффективности различных реализаций какого-либо алгоритма. В настоящей статье описаны появляющиеся новые возможности энциклопедии AlgoWiki, направленные на создание связанного представления различных алгоритмических подходов решения одной и той же задачи. На это нацелено описание предметной области в виде цепочек задача-метод-алгоритм-реализация, дополненное возможностями формирования рейтингов на базе любых алгоритмов энциклопедии, а также механизмом архитектурных срезов., AlgoWiki is an open encyclopedia of algorithms' properties and features of their implementations on different hardware and software platforms. It can be used to achieve various aims, for example, to search for the optimal algorithm to solve a certain problem, to analyze the information structure of an application or to compare the efficiency of different implementations of an algorithm. This paper describes the emerging new features of the AlgoWiki encyclopedia aimed at creating a joint presentation of various algorithmic approaches to solve the same problem. This is the aim of the subject area description in the form of chains problem-method-algorithm-implementation supplemented by the possibility of generating ratings based on any algorithms of the encyclopedia as well as a mechanism of architectural profiles., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 3 2019

Алгоритм PAM (Partitioning Around Medoids) представляет собой разделительный алгоритм кластеризации, в котором в качестве центров кластеров выбираются только кластеризуемые объекты (медоиды). Кластеризация на основе техники медоидов применяется в широком спектре приложений: сегментирование медицинских и спутниковых изображений, анализ ДНК-микрочипов и текстов и др. На сегодня имеются параллельные реализации PAM для систем GPU и FPGA, но отсутствуют таковые для многоядерных ускорителей архитектуры Intel Many Integrated Core (MIC). В настоящей статье предлагается новый параллельный алгоритм кластеризации PhiPAM для ускорителей Intel MIC. Вычисления распараллеливаются с помощью технологии OpenMP. Алгоритм предполагает использование специализированной компоновки данных в памяти и техники тайлинга, позволяющих эффективно векторизовать вычисления на системах Intel MIC. Эксперименты, проведенные на реальных наборах данных, показали хорошую масштабируемость алгоритма., The PAM (Partitioning Around Medoids) is a partitioning clustering algorithm where each cluster is represented by an object from the input dataset (called a medoid). The medoid-based clustering is used in a wide range of applications: the segmentation of medical and satellite images, the analysis of DNA microarrays and texts, etc. Currently, there are parallel implementations of PAM for GPU and FPGA systems, but not for Intel Many Integrated Core (MIC) accelerators. In this paper, we propose a novel parallel PhiPAM clustering algorithm for Intel MIC systems. Computations are parallelized by the OpenMP technology. The algorithm exploits a sophisticated memory data layout and loop tiling technique, which allows one to efficiently vectorize computations with Intel MIC. Experiments performed on real data sets show a good scalability of the algorithm., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 2 2019

Обратная задача 3D ультразвуковой томографии рассматривается в статье как нелинейная коэффициентная обратная задача для уравнения гиперболического типа. Используемая математическая модель хорошо описывает как дифракционные эффекты, так и поглощение ультразвука в неоднородной среде. В рассматриваемой постановке реконструируется скорость распространения акустической волны как функция трех координат. Количество неизвестных в нелинейной обратной задаче составляет порядка 50 миллионов. Разработанные итерационные алгоритмы решения обратной задачи ориентированы на использование GPUкластеров. Основным результатом работы является апробация алгоритмов на экспериментальных данных. В эксперименте использовался стенд для 3D ультразвуковых томографических исследований, разработанный в МГУ имени М.В. Ломоносова. Акустические параметры фантомов близки к акустическим параметрам мягких тканей человека. Объем экспериментальных данных составляет порядка 3 ГБ. Интерпретация данных эксперимента позволила не только продемонстрировать эффективность разработанных алгоритмов, но и подтвердила адекватность математической модели реальности. Для реализации разработанных численных алгоритмов использовался графический кластер суперкомпьютера Ломоносов-2., The inverse problem of 3D ultrasound tomography is considered in this paper as a nonlinear coefficient inverse problem for a hyperbolic equation. The employed mathematical model accurately describes the effects of ultrasound wave diffraction and absorption in inhomogeneous media. The velocity of acoustic waves inside the test sample is reconstructed as an unknown function of three spatial coordinates. The number of unknowns in the nonlinear inverse problem reaches 50 million. The developed iterative algorithms for solving the inverse problem are designed for GPU clusters. The main result of this study is testing the developed algorithms on experimental data. The experiments were carried out using a 3D ultrasound tomographic setup developed at Lomonosov Moscow State University. Acoustic properties of the test samples were close to those of human soft tissues. The volume of data collected in experiments is up to 3 GB. Experimental results show the efficiency of the proposed algorithms and confirm that the mathematical model is adequate to reality. The proposed algorithms were tested on the GPU partition of Lomonosov2 supercomputer., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 3 2019

The weighed and unweighted minimal set-cover problem, its applicability for the solution of the major optimization practical tasks, such as arrangement of service points, assignment of crews in transport, as well as the integrated-circuit and conveyer lines designing is considered. The paper objective is to describe methods of improving efficiency of this task solution. The principle of operation of the genetic algorithm and the applicability of its modification as a method of the solution to the set-cover problem are defined. Greedy strategy of Chvatal for the set-cover problem solution is considered. An exhaustive algorithm as an exact algorithm for the solution of small-size tasks is developed. The modified genetic algorithm developed by Nguyen M. H. is described. A software tool for comparing the performance of these algorithms is created. It is concluded that the solution of the set-cover problem by our genetic algorithm modification is more effective than by the genetic algorithm of Nguyen M. H. or the greedy strategy. And the results obtained in small-size tasks are noted for insignificant error.

A different kinds of databases, based on the relational algebra models, are used at present time. In case of graphical databases the known models are need of very large information resources for the data store and data management. In this paper a geometrical approach to the data granulation presented. As a practical result of granulation very sufficient data compression is obtained. Thepractical application of the new kind of data models is the image databases for the complicated form objects

The study of statistical data for outliers is an urgent task of modern mathematics. The reliability of these methods directly affects the quality of the subsequent processing of statistical data sets and the adequacy of the resulting conclusions. In general, all available observations should be checked and compared with a certain numerical indicator. The further conclusion should be made by comparing these indicators among themselves.In this paper, a technique to search for statistical outliers for one of the possible regression models based on the Chebyshev norm is considered. The proposed approach is based on the Legendre transformation, one of the known transformations used in the convex analysis. This algorithm allows us to refer to the group of statistical outliers for a set of observations and not for individual observations. This key point distinguishes this algorithm from the most of the commonly used algorithms. This way, the task can be solved in one pass with less required time. An example of the study of a sample for outliers is presented. The possibility to compare the obtained characteristics provides the opportunity to solve the problem for a different number of assumed extreme values.DOI 10.14258/izvasu(2018)4-18, Изучение статистических данных на предмет выбросов является актуальной задачей современной математики. От надежности данных методов напрямую зависит качество последующей обработки массива данных и адекватность получаемых выводов. В общем случае данная задача предусматривает проверку всех имеющихся наблюдений и сопоставление с ними некого числового индикатора. Дальнейший вывод делается на основе сопоставления этих индикаторов между собой.В данной работе рассматривается методика поиск выбросов для одной из возможных регрессионных моделей, основанной на чебышевской норме. В основу предлагаемого подхода положено одно из известных преобразований, использующееся в выпуклом анализе, — преобразование Лежандра. Основанный на этом преобразовании алгоритм позволяет относить к группе выбросов не отдельные наблюдения, а множество наблюдений. Это отличает данный метод от большинства использующихся алгоритмов. Также это позволяет решить поставленную задачу за один проход и сокращает время выполнения алгоритма. Приводится пример исследования выборки на предмет выбросов. Возможность сравнения получаемых характеристик дает возможность решать задачу для различного количества предполагаемых экстремальных значений.DOI 10.14258/izvasu(2018)4-18

An algorithm for determining the measure of the spatial distribution of point sets based on the spatial hashing algorithm is proposed. In this paper we extend the measure of the spatial density of a point set to a three-dimensional space. The developed approach allows us to identify the correlation of two point sets as a scalar product of the density distribution of nearest neighborhood index, which makes it possible to solve the problems of segmentation of point sets. Figs.: 2. Refs.: 15 titles.Keywords: point set; spatial hashing; measure of the spatial density; nearest neighborhood index; point set segmentation., В работе предложен алгоритм для определения меры пространственного распределения точечных множеств на основе алгоритма пространственного хеширования. В работе вводится расширение меры пространственной плотности точечного множества на трехмерное пространство. Разработанный подход позволяет выявлять корреляцию двух точечных множеств как скалярного произведения распределения плотностей индексов ближайшего соседства, что дает возможность решать задачи сегментации точечных множеств. Ил.: 2. Библиогр.: 15 назв.Ключевые слова: точечное множество; пространственное хеширование; мера пространственной плотности; индекс ближайшего соседства; сегментация точечного множества., В роботі запропоновано алгоритм для визначення міри просторового розподілу точкових множин на основі алгоритму просторового хешування. В роботі вводиться розширення міри просторової густини точкової множини на тривимірний простір. Розроблений підхід дозволяє визначати кореляцію двох точкових множин як скалярного добутку розподілу густини індексів найближчого сусідства, що дозволяє розв’язувати задачі сегментації точкових множин. Іл.: 2. Бібліогр.: 15 назв.Ключові слова: точкова множина; просторове хешування; міра просторової густини; індекс найближчого сусідства; сегментація точкових множини.

Determination of protein concentration in biological samples is an important task for biological research, as well as for medicine and routine clinical biochemistry. The introduction of stable isotope-labeled peptide standards (SIS) made it possible to determine accurately absolute protein concentrations in proteomic studies. The correct choice of SIS and the systematic way to develop a s method for selected reaction monitoring (SRM) are very important steps that are crucial for further identification and measurements of protein concentration. In this paper, we summarize our experience of selecting SIS for measuring the protein concentration by SRM. The results are presented in the form of an algorithm that describes the main stages of the SIS selection and the main points in the development of SRM methods for the targeted protein detection and determination of protein concentrations in biological samples., Определение концентраций белков является важной задачей в биологии и медицине, а также используется в клинической лабораторной практике для диагностики заболеваний. Измерения абсолютных концентраций белков в масс-спектрометрии стали возможны благодаря внедрению в практику внутренних стандартов, которые в точности соответствуют химической структуре измеряемого вещества, но синтезированы с использованием изотопно-меченых молекул. Правильный выбор внутреннего стандарта и систематических подход в разработке методики мониторинга выбранных реакций (Selected Reaction Monitoring, SRM) определяет качество идентификации и точность измерения концентрации таргетного белка. В данной работе суммирован наш опыт по выбору пептидного стандарта для измерения концентрации белков. Результаты представлены в виде алгоритма, который учитывает основные стадии выбора внутреннего стандарта и основные моменты разработки методов детекции и определения концентрации белков

Статья посвящена разработке методики исследования масштабируемости ресурсоемких итерационных алгоритмов, применяемых в моделировании сложных физических процессов на суперкомпьютерных системах. В основе предлагаемой методики лежит модель параллельных вычислений BSF (Bulk Synchronous Farm), позволяющая на ранней стадии разработки итерационного алгоритма определить границу его масштабируемости. Модель BSF предполагает представление алгоритма в виде операций над списками с использованием функций высшего порядка. При этом рассматривается два класса представлений: BSF-M (Map BSF) и BSF-MR (Map-Reduce BSF). Предлагаемая методика описывается на примере решения систем линейных алгебраических уравнений методом Якоби. Для метода Якоби строится два итерационных алгоритма: Jacobi-M на основе представления BSF-M и Jacobi-MR на основе представления BSF-MR. Для указанных алгоритмов с помощью стоимостных метрик модели BSF даются аналитические оценки для ускорения, эффективности распараллеливания и верхней границы масштабируемости для многопроцессорных вычислительных систем с распределенной памятью. Приводится информация о реализации этих алгоритмов на языке C++ с использованием программного шаблона BSF и библиотеки параллельного программирования MPI. Демонстрируются результаты масштабных вычислительных экспериментов, выполненных на кластерной вычислительной системе. На основе экспериментальных результатов дается анализ адекватности оценок, полученных аналитическим путем с помощью стоимостных метрик модели BSF., This paper is devoted to the development of a methodology for evaluating the scalability of compute-intensive iterative algorithms used for simulating complex physical processes on supercomputer systems. The proposed methodology is based on the BSF (Bulk Synchronous Farm) parallel computation model, which makes it possible to predict the upper scalability bound of an iterative algorithm in early stages of its design. The BSF model assumes the representation of the algorithm in the form of operations on lists using high-order functions. Two classes of representations are considered: BSF-M (Map BSF) and BSF-MR (Map-Reduce BSF). The proposed methodology is described by the example of solving a system of linear equations by the Jacobi method. For the Jacobi method, two iterative algorithms are constructed: Jacobi-M based on the BSF-M representation and Jacobi-MR based on the BSF-MR representation. Analytical estimations of the speedup, parallel efficiency and upper scalability bound are obtained for these algorithms using the BSF cost metrics on multi-processor computing systems with distributed memory. These algorithms are implemented on C++ language using the BSF program skeleton and MPI parallel programming library. The results of large-scale computational experiments performed on a cluster computing system are discussed. Based on the experimental results, an analysis of the adequacy of estimations obtained analytically using the BSF cost metric is made., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 4 2018

Purpose. In this paper, for simultaneous placement of distributed generation (DG) and capacitors, a new approach based on Spring Search Algorithm (SSA), is presented. This method is contained two stages using two sensitive index Sv and Ss. Sv and Ss are calculated according to nominal voltage and network losses. In the first stage, candidate buses are determined for installation DG and capacitors according to Sv and Ss, Then in the second stage, placement and sizing of distributed generation and capacitors are specified using SSA. The spring search algorithm is among the optimization algorithms developed by the idea of laws of nature and the search factors are a set of objects. The proposed algorithm is tested on 33-bus and 69-bus radial distribution networks. The test results indicate good performance of the proposed method., Цель. В статье для одновременного размещения распределенной генерации и конденсаторов представлен новый подход, основанный на «пружинном» алгоритме поиска (Spring Search Algorithm, SSA). Данный метод состоит из двух этапов с использованием двух показателей чувствительности Sv и Ss. Показатели чувствительности Sv и Ss рассчитываются в соответствии с номинальным напряжением и потерями в сети. На первом этапе определяются шины-кандидаты для установки распределенной генерации и конденсаторов согласно Sv и Ss. Затем, на втором этапе размещение и калибровка распределенной генерации и конденсаторов выполняются с использованием алгоритма SSA. «Пружинный» алгоритм поиска входит в число алгоритмов оптимизации, разработанных на основе идей законов природы, а факторы поиска представляют собой набор объектов. Предлагаемый алгоритм тестируется на радиальных распределительных сетях с 33 и 69 шинами. Результаты тестирования показывают хорошую эффективность предложенного метода.

Статья посвящена моделированию трещиноватых резервуаров. Построена трехмерная статистическая модель дискретной системы трещин. Предложен эффективный метод генерирования случайных реализаций статистической модели для произвольной расчетной сетки. Решена задача масштабирования модели трещин с использованием анализа сейсмических изображений статистической модели для различных значений шага сетки., This paper is devoted to modeling of fractured reservoirs. A three-dimensional statistical model of a discrete fracture network is developed. An efficient method to generate the random realizations of the statistical model for an arbitrary computational grid is proposed. The problem of scaling the fracture model using the analysis of seismic images for different grid steps is solved., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 3 2018

This paper describes a method of on-line signature identification using the short-time Fourier transform and wavelet transform with radial basis of a special kind. In carrying out the identification, we use dynamic properties signature. We adduce the assessment of the reliability of the proposed procedure.

В Научно-исследовательском центре электронной вычислительной техники (НИЦЭВТ) разрабатывается высокоскоростная коммуникационная сеть Ангара с топологией "многомерный тор". При эксплуатации вычислительного кластера с сетью Ангара в условиях наличия занятых и отказавших узлов возникает задача поиска оптимального подмножества узлов сети для покрытия заданного числа узлов так, чтобы весь сетевой трафик лежал внутри этого подмножества узлов. В настоящей статье представлен приближенный полиномиальный алгоритм решения такой задачи., The Angara high-speed interconnect with multidimensional torus topology is under development in Scientific Research Center for Electronic Computer Technology. During the utilization of the Angara interconnect in cluster systems, there exist busy and failed nodes. Thus, there is a problem of finding an optimal cluster node subset such that the network traffic belongs to this node subset and the node subset size is not less than a given size. The paper presents an approximate algorithm for solving this problem., ВЫЧИСЛИТЕЛЬНЫЕ МЕТОДЫ И ПРОГРАММИРОВАНИЕ: НОВЫЕ ВЫЧИСЛИТЕЛЬНЫЕ ТЕХНОЛОГИИ, Выпуск 1 2017

The paper provides a review of the existing methods of signals processing within the conditions of the Rice statistical model applicability. There are considered the principle development directions, the existing limitations and the improvement possibilities concerning the methods of solving the tasks of noise suppression and analyzed signals filtration by the example of magnetic-resonance visualization. A conception of a new approach to joint calculation of Rician signals both parameters has been developed based on the method of moments in two variants of its implementation. The computer simulation and the comparative analysis of the obtained numerical results have been conducted.

The paper presents an canonical method of the swarm particles in two modifications to raise this method efficiency in solving multi-extreme problems of high dimension optimization. The essence of PSO-M1 modification is to form two new points to attract swarm particles (along with the points which are responsible for inertial, cognitive, and social components of canonical method). These new points represent the best points of sets of particles-neighbours of a given point. The modification aims to diversify search. All free parameters of the PSO-M1 method (as well as an canonical method) are static. In contrast, one of such parameters of PSO-M2 modification is dynamic. So this modification represents an example of a self-adaptive method of optimization. The modification aims to intensify search. A computing experiment to study the method efficiency and its abovementioned modifications at solving the test problems of optimization showed advantages of offered modifications in comparison with canonical method, revealed a superiority of PSO-M2 modification both over canonical method, and over PSO-M1 modification. Using the PSO-M2 method allows us to solve the 28-dimensional molecular docking problem of HIV1 protease and darunaviry 3U7S as the molecules of receptor and a ligand, respectively. Results of computing experiment have shown that the PSO-M2 method successfully finds the position of ligand close to native and can be recommended for solving the molecular docking problems as an alternative to genetic algorithm.

The most important design solutions of production engineering for the assembly operation are an assembly sequence and assembly chart. Both are closely linked with each other and therefore are recorded in the single process flow sheet that is an assembly chart.Capability for successive order assembling and splitting into assembly units depends on a set of the product design properties from which the main ones are position mechanical connections used to locate details within a product. An adequate mathematical model of the mechanical connections of technical system is a hyper graph. It allows us to give the correct description of the location relation of variable-locality.The analysis of the array of drawings shows that many designs contain redundant mechanical connections. The inequality is a criterion of redundancy, where |X| is the number of tops of the hyper graph (details), and |R| is the number of hyper edges (full assembly bases). Excess of mutual coordination is a harmful phenomenon which at designing stage exhibits as unsolvable dimension chains, while at the assembly stage it shows as relocation. Redundant connections should be removed from a design at the earliest design-for-manufacturing stages. Removal of connections generates mechanical structures with different assembly properties. The work offers some important criteria of generation of irredundant mechanical structures. The paper considers in detail a maximum decomposition criterion, which allows us to receive structures with the greatest capability to split into assembly units. It shows that such structures exhibit high flexibility in assembling and are adaptable to various specifications and production processes.

This paper presents the results of a comparative analysis of Serbian phonemes. The characteristics of vowels are quasi-periodicity and clearly visible formants. Non-vowels are short-term quasi-periodical signals having a low power excitation signal. For the purpose of this work, speech production systems were modelled with linear AR models and the corresponding non-linear models, based feed-forward neural networks with one hidden-layer. Sum squared error minimization as well as the back-propagation algorithm were used to train models. The selection of the optimal model was based on two stopping criteria: the normalized mean squares test error and the final prediction error. The Levenberg-Marquart method was used for the Hessian matrix calculation. The Optimal Brain Surgeon method was used for pruning. The generalization properties, based on the time-domain and signal spectra of outputs at hidden-layer neurons, are presented.

A radar target whose return varies up and down in amplitude as a function of time represents the basis of a large number of real targets. This paper is intended to provide a complete analysis of CFAR detection of fluctuating targets when the radar receiver post-detection integrates M returned pulses from χ 2 fluctuating targets with two and four degrees of freedom and operates in a non-ideal environment. Owing to the importance of Swerling models in representing a large number of such type of radar targets, we are interested here in adaptive detection of this class of fluctuation models. Swerling cases I and III represent scan-to-scan fluctuating targets, while cases II and IV represent fast pulse-to-pulse fluctuation. Exact expressions of detection probability are derived for all of these models. A simple and an effective procedure for calculating the detection performance of both fixed-threshold and adaptive-threshold algorithms is obtained. In the CFAR case, the estimation of the noise power levels from the leading and the trailing reference windows is based on the CA technique. The performance of this detector is analyzed in the cases when the operating environment is ideal and when it includes some of spurious targets along with the target of interest. The primary and the secondary interfering targets are assumed to be fluctuating in accordance with the four Swerling’s models cited above. The numerical results show that for strength target return the processor detection performance is highest in the case of SWIV model while it attains its minimum level of detection in the case of SWI model. Moreover, SWII model has higher performance than the SWIII representation of fluctuating targets. For weak target return, on the other hand, the reverse of this behavior is occurred. This observation is common for both fixed-threshold or for adaptive-threshold algorithms.

This paper is devoted to the problem of an observable form for a given Timed Finite State Machine. This problem, together with the problem of the number of states in the observable form, has theoretical value, since it shows the way to build an observable form, and answers the question, does an observable form exist for any TFSM. Also it has a practical use in testing, since Finite State Machine methods of test generation rely on the fact that specification of a system is an observable FSM and those methods are intended to be applied for TFSMs.

The paper addresses the problem of the relationship between tests with the guaranteed fault coverage which are derived from two models of finite transition systems: LTS with inputs and outputs and input/output FSM. On one hand, there are well developed methods for deriving such finite tests against FSM while the model of input/output LTSs lacks such methods. On the other hand, almost all FSM-based methods return preset test suites and there are no good FSM-based methods for deriving adaptive tests. For deriving adaptive tests, it is worth to use LTS model where all the methods return adaptive test suites. We propose the transformation between two models and show how a complete test suite with respect to one model can be transformed into a complete test suite with respect to another model.