Статьи журнала - Вестник Южно-Уральского государственного университета. Серия: Компьютерные технологии, управление, радиоэлектроника
Все статьи: 1048
Optimization of time resource parameters and corporate training results
Статья научная
This article proposes a mathematical model for drafting the corporate training time-table which describes the time resource limitations imposed on the said processes and aims at the optimization of the target results. The training process is discussed as being integrated into the key corporate business processes. The employees are grouped into functions, with a set of alternative curricula assigned to each group. Such curricula vary by length, effect on the key competences, quality and cost of business processes. The efficiency of attainment of the educational process goals varies due to the alternative selection of the curricula for various staff groups and distribution of the training events in time. The formalized mathematical model is a linear programming integer model with a specific block limitation matrix. The parameters of its target functions and limitations are built according to a series of domestic and foreign assessment theories for the corporate training curricula. The optimum solution of the problem is achieved through the branch and bound method and left-hand tree traversal. The structure of the dual problem provides for easy evaluation of vertexes based on the duality theory.
Бесплатно
Optimum ECG signal filtering based on wavelet transformation
Краткое сообщение
The development of digital signal processing and microprocessor technology creates conditions for improving methods for diagnosing the functional state of organs. Wavelet analysis is a modern and promising method of information processing. In order to determine the effective optimal filtering of the electrocardiography signal based on the wavelet transform, wavelet filtering was performed using wavelets of different families, the efficiency of using different levels of decomposition, methods for calculating the threshold and types of the threshold function was investigated. Aim. Determination of effective optimal filtering of electrocardiography signal based on wavelet transform. Materials and methods. Cardiograms were taken for analysis. Then they were digitized and entered into a computer for processing. A program was written in the Matlab environment that implements continuous and discrete wavelet transform. Results. As a result of the research, 56 combinations of noise reduction parameters were tested for three noise levels. It was found that the maximum degree of signal purification from noise was obtained using the Coiflets 5 wavelet using a rigid thresholding method, with a heuristic method for calculating the threshold value. Wavelet Simlet 8 has lower correlation coefficient values than Coiflets 5, at 35 dB the best result is 97%, the noise level is 40 dB the best result is 98.7%, the noise level is 45 dB the best result is 99.3%, which is generally negligible differs from the correlation coefficients of the wavelet Coiflets 5. Conclusion. As a result of the study, the first and the present work, the following conclusions were made: the optimal level of the wavelet decomposition of the ECG signal N = 2; the maximum degree of signal cleaning from noise was obtained using the Coiflets 5 wavelet using a rigid thresholding method, with a heuristic method for calculating the threshold value; Simlet 8 wavelet using a soft thresholding method with a minimax thresholding method also shows noteworthy results, slightly inferior to Coiflets 5 wavelet results.
Бесплатно
Opto-ultrasonic communication channels
Статья научная
Introduction. Ultrasound is widely used in various applications, such as monitoring the state of structures, biomedical ultrasound imaging, and information (data) transmission. Ultrasonic transceivers are one of the modern communication systems, both for short-range and remote access. Indeed, the technology of the process of transmitting information using communication channels based on ultrasonic (US) vibrations and the physical implementation of transmission using optical fiber are widely used in conditions of confidentiality of data processing. At the same time, the needs of wireless and wired communication demanded the development of more advanced applications (software, hardware solutions). In particular, new challenges have arisen requiring transceivers to have high frequency, wide bandwidth and compact size. Aim. Consider the “technology - opto-ultrasonic” approach used in data transmission and reception channels. This technology involves the generation of ultrasound by a pulse using the optical-acoustic effect, followed by the reception and processing of ultrasonic vibrations. Optical ultrasonic transceivers based on the photo-acoustic (US) principle of operation have great potential, in particular, to obtain the necessary: (super high) frequency of the transmitted signal; wide bandwidth (speed); ease of use as transceivers; low manufacturing cost. Materials and methods. Various methods of spectral analysis (Fourier and Wavelet) have been investigated to ensure the achievement of the above goal. Results. Compared to traditional technologies of information reception and transmission, optical ultrasonic transceivers provide high-frequency communication, wide bandwidth and compact size. Conclusion. The paper investigates the methods of spectral analysis (Fourier and Wavelet) and proposes, based on these studies, possible options for the implementation of optical ultrasonic transceivers that can generate ultrasonic pulses with a duration on a nanosecond scale using an ultrafast laser and receive confidential data with a high degree of security. At the same time, by combining the principle of generating photo-acoustic ultrasound with the use of optical fiber, it is possible to obtain compact and inexpensive ultrasonic transceivers.
Бесплатно
Phase converter of composing displacement
Статья научная
Minimax strategy of mechatronic converters efficiency improving relative to error decrease with velocity increase at the same time provides common dataware level rise. The analysis of usage possibilities of different type position transducers (PT) gives the advantages of resolvers. The subsequent processing of their output signals is performed by “Resolver-to-Digit” Converter (RDC) which provides displacement digital equivalent and digital or analog signals specifying its velocity and acceleration. With appearance new electronic component, including microcontroller, for increasing of accuracy of the measurements of the corner of the tumbling resolver possible to use such methods, which earlier realize was not on. Given article contains the offers about the most further development of the technical decisions for RDC of the corner. Replaceable elementary substracting section, traditionally used in all, without exception, schemes of the automatic regulation, on more “intellectual” statistical section, possible avoid the influence signals in sidebar to feedback on accuracy of the transformation.
Бесплатно
Planning of personal trajectors of development: systems of automated design
Краткое сообщение
The problem of planning personal development trajectories in the implementation of computer-aided design systems in conditions of uncertainty and risk is considered. The aim of the research is the network planning of personal development trajectories when implementing computer-aided design systems on the basis of a competency model that requires reasoning. To minimize risks, a level model of competencies has been developed, taking into account education, work experience, certificates and functional responsibilities. The process of building a competency model for the implementation of automated process design systems is described. The developed algorithm and the program allows to solve the problem of network planning of personal development trajectories by the criteria of minimization of time and cost costs. The results of the research are used in the educational process of the South Ural State University and the Azerbaijan Technical University when training personnel for work with the systems of computer-aided design of technological processes.
Бесплатно
Principle of coordinated planning in control of distributed projects and programs
Статья научная
The paper deals with the problem of managing distributed projects and programs. These programs consist of subprograms distributed functionally, administratively or geographically. For instance, a program of regional development includes a subprogram of environmental safety. In this regard, the main problem of managing distributed programs is the problem of interests' coordination for all persons concerned. We propose the principle of coordinated planning for designing implementation plans of distributed programs.
Бесплатно
Regulation of the activities of JSC “Russian Railways”: expert evaluation of options for improving
Статья научная
The problem of the structural reform of railway transport in Russia is being considered in the article. Two ways of the reform are suggested, the methodology and results of the expert evaluation of the options are described in detail. There have been shown the experience dealing with the use of expert technology; in particular it has to do with the tools of the qualitative and quantitative estimation of the options by using the modified models of so-called Osgood’s semantic differential which is widely used in the sociology. There are the questionnaires prepared for the examination; there are the results of the questionnaire of the expert group of qualified specialists of the Institute of Economics and industrial engineering of the Russian Academy of Sciences and the Siberian State Transport University. When finding a solution there have been used game theory methods, in particular, the theory of Nash equilibrium strategies, Wald’s maximum criterion, Maximax, Hurwicz's, Savage's criterion. The results allow making several significant conclusions which suppose to encourage the optimal solution in the structural reform of railway transport in Russia.
Бесплатно
Requirements for distributed information systems to support scientific and educational activities
Краткое сообщение
To increase the effectiveness of research, it is necessary to have access to systematic information resources of scientific work. Therefore, in any field of science, it begins with research, the search for scientific information, but with the growing number of scientific articles, books, monographs, patents, the search for information becomes more and more difficult. Creating a unified information system that allows scientists to quickly get acquainted with the results of other scientific research and prevent their duplication. The main tasks of creating a model of a distributed information system that supports scientific and educational activities, the functional capabilities of the model, the concept of metadata, and the requirements for the metadata profile are described. The task, subject area, subjects, objects, the main functionality of the information system are defined, a list of the main types of information resources is provided. The paper analyzes the functional requirements for such systems. Purpose. In the process of creating distributed information systems that support scientific and educational activities, it is necessary to study the requirements imposed on the information system. Methods. The article discusses in detail technological methods for constructing models of information systems for supporting scientific and educational activities. Results. Using the requirements, models, metadata of a distributed information system supporting scientific and educational activities, the architecture of the information system was developed and a scheme for exchanging information in the information system through information protocols was presented. Conclusion. The article discusses technological methods of a distributed information system that supports scientific and educational activities. The main tasks for building a model of a distributed information system supporting scientific and educational activities, ensuring the functional functioning of the model, the concept of metadata for this system, and the requirements for the metadata profile are described. Based on the proposed requirements, the architecture of a distributed information system supporting scientific and educational activities has been developed and the structure has been clearly described.
Бесплатно
Resolver-to-digital converters with the arctangent function transformation
Статья научная
The work is devoted to the peculiarities of the construction of amplitude converters of type “angle-parameter-code”, in which arctangent function transformation is used when converting output signals of a resolver into a digital equivalent of movement. The features of the construction of brushless classical resolvers and varieties of their variable reluctance, in Russia known as reductosin, are considered. It allows to realize an electrical reduction, at which the sensor accuracy increases considerably. The principle of operation of the resolver, output signals of which contain reliable information about components of displacement of the rotor, is found out. Resolver-to-Digital Converter (RDC) corresponds to the postulate of the general theory of relativity on communication of space and time. A special place among one-component “angle-parameter-code” converters is held by the structures using arctg-conversion, at which quadrant or octant range splitting of the transformation of angular displacement is used. In the first case, angular transformation is implemented by the digital signal processor (DSP) or microcontroller, and in the second one - by ROM with arctg insertion. The structure and ratios necessary for calculation of movement by software and tabular implementation of arctangent function transformation. An original version of the analog-to-digital converter with arctg ROM is presented. Its capacity at identical length of the output code is four times less than the capacity of traditionally used ROM with a sine-cosine firmware. Octant representation of a full range transformation of the angle of rotation allows to generate an additional high order digit of the output code in comparison with a traditional quadrant band splitting. This not only improves the resolution of the conversion twice, but also simplifies coordination of samples at application of an electrical reduction with the reductosin.
Бесплатно
Review of image reconstruction methods in X-ray computed tomography with cone-beam geometry
Статья научная
The article reflects the main task of the X-ray computed tomography and its mathematical description. Direct and inverse Radon transform are given. The methods of image reconstruction in X-ray computed tomography are presented. Their brief classification are given. The author have reviewed classical problem of two-dimensional computed tomography and basics approaches to its solution. Emphasis is placed on back projection algorithm with filtering convolution. The derivation of the algorithm for parallel and fan-beam reconstruction are given. The analysis of the problem of three-dimensional reconstruction are presented. The author describes the additional conditions imposed on the projection data, the computational efficiency of the algorithms and the quality of the images. The basic trajectory of the X-ray source, providing the condition Tuy, are considered. The article gives an overview of existing methods of three-dimensional reconstruction with cone-beam geometry, their advantages, disadvantages, clinical applications. Their brief classification are given. Approximate algorithms of three-dimensional reconstruction are presented. The Feldkamp algorithm, the extended parallel backprojection, and the advanced single-slice rebinning are described. The author raises the question of developing approaches and methods for obtaining images with three-dimensional reconstruction for cone-beam spiral CT.
Бесплатно
Robustness measure for portfolio management strategy
Статья научная
A practical approach to estimating of the investment strategy robustness is presented. As a quantitative measure of robustness, the objective function smoothness degree is proposed for utilization. After the optimization has been conducted, it is essential to utilize an additional criterion for the selection of strategies that possess better robustness property. The utilization of the quantitative estimate of the strategy robustness enables a better strategy to be chosen in the efficiency analysis of investment systems. This strategy is more stable and provides higher return in various stock market conditions, including the sideways trend and downtrend.
Бесплатно
S-матрица системы материальных точек, взаимодействующих по закону всемирного тяготения
Статья научная
Предложен метод решения основной задачи небесной механики об эволюции системы N материальных точек, взаимодействующих между собой по закону всемирного тяготения Ньютона. Метод основан на сведении задачи Коши для системы дифференциальных уравнений движения системы n материальных точек, следующих из второго закона динамики, к эквивалентной системе интегральных уравнений Вольтерра. При помощи мультипольного разложения напряжённости гравитационного поля получена иерархия интегральных уравнений Вольтерра с различными степенными нелинейностями. Показано, что в линейном приближении основная задача небесной механики может быть сформулирована как задача многочастичного рассеяния.
Бесплатно
SVG-моделирование управляемых систем тел
Краткое сообщение
Описаны новые функциональные возможности программной системы (ПС) «СистемаТел», основанной на XML-технологиях, в которой для 3D-моделирования управляемых систем тел (СТ) используется расширяемый язык разметки трехмерной векторной графики (X3D). А для 2D-моделирования СТ используется скалярная векторная графика (SVG). Выполнен краткий обзор ПС моделирования роботов, использующих XML-ориентированные языки (URDF, SRDF, PLM) разметки параметров роботов. Указано на основное отличие ПС «СистемаТел» от ее аналогов. Оно связано с тем, что в ПС «СистемаТел» коллизии описываются как условия перехода от одной структуры СТ к другой, а не перехватываются в процессе графического моделирования, например, как события столкновения двух тел. Предложен язык XsysTel разметки СТ, состоящий из корневого узла и узлов , . Структура вложенности узла декларирует структуру СТ. Поля узла расширяют его использование до описания кинематических, статических и динамических свойств СТ. В узле описываются неудерживающие и динамические связи, зависящие от состояния и структуры СТ. Предложена структурная классификация СТ. В ПС «СистемаТел» различают СТ с одной Открытой Ветвью (СТОВ), СТ с одной замкнутой Ветвью (СТВ), Древовидную СТ с Открытыми Ветвями (ДСТОВ), Древовидную СТ с открытыми и замкнутыми Ветвями (с циклами) (ДСТВ). К ДСТ относится СТ, в которой структура меняется в процессе движения тел. Приведен пример СТ с изменяющейся структурой. Условия перехода между структурами могут быть геометрическими, кинематическими и динамическими, например, в виде неравенств, содержащих динамические реакции в сочленениях тел. Приведены примеры XsysTel-описания СТ на плоскости (ПСТ). Рассмотрена плоская СТОВ (ПСТОВ) и плоская ДСТ (ПДСТ) в виде моделей двуногого шагающего аппарата в одноопорной и двухопорной фазах ходьбы, а также в фазе полета. Разработан алгоритм XSLT-преобразования XsysTel-описания ПСТ в SVG-модель ПСТ.
Бесплатно
Simple stability tests for second order delay differential equations
Краткое сообщение
For linear and nonlinear delay differential equations of the second order with damping terms exponential stability and global asymptotic stability conditions are obtained. The results are based on the new sufficient stability conditions for systems of linear equations. The results are illustrated with numerical examples, and a list of relevant problems for future research is presented. We proposed a substitution which exploits the parameters of the original model. By using that approach, a broad class of the second order non-autonomous linear equations with delays was examined and explicit easily-verifiable sufficient stability conditions were obtained. There is a natural extension of this approach to stability analysis of high-order models. For the nonlinear second order non-autonomous equations with delays we applied the linearization technique and the results obtained for linear models. Our stability tests are applicable to some milling models and to a non-autonomous Kaldor-Kalecki business cycle model. Several numerical examples illustrate the application of the stability tests. We suggest that a similar technique can be developed for higher order linear delay equations, with or without non-delay terms.
Бесплатно
Краткое сообщение
The sponge titanium production technology process is considered. Its control problems are considered. The positional control system of sponge titanium vacuum separation is investigated by simulation in the software environment Simulink (MATLAB). The process control capabilities with two standard types of controllers (position and PI) are considered. The optimal parameters of the position controller are selected using tabular method in MS Excel. The optimal parameters of the PI-con¬troller are selected in the software environment Simulink (MATLAB). The transients are obtained with position and PI-controller. The impossibility of standard control methods using to this task has proved. The necessity to use more sophisticated methods of control to improve the quality of control has proved.
Бесплатно
Smart management methods and mechanisms of industrial enterprises and organizations
Статья научная
At present, the management of industrial enterprises and organizations becomes an increasingly challenging problem, so old traditional methods are impossible to use for its solving. This article describes methods and mechanisms of smart management that improve management efficiency of industrial enterprises and organizations. These mechanisms are grouped as follows: - non-manipulative mechanisms (or mechanisms allowing to get right information from employees about their working results); - coordination mechanisms (when using such mechanisms it is rational for employees to fulfill commitments or plans); - supporting mechanisms (mechanisms that help develop recommendations to the decision maker); - developing mechanisms (mechanisms stimulating the development of industrial enterprises (cost reduction, innovation, etc.)). In this article, we analyze why still so few smart management methods and mechanisms are used in practice.
Бесплатно
Spectrum transformation of an amplitude-modulated signal on an Ohmic nonlinear element
Статья научная
Introduction. In many physical processes, the spectrum of the modulated signal is transferred to the low-frequency region, which also manifests itself in active dielectrics in radio sound. In the general case, the analysis of the spectrum transformation process is a very difficult task related with solving a system of nonlinear differential equations. And in the accepted form, the principle of superposition is not applicable here, since the parameters of the output signal cannot be determined by algebraic summation of the signals received separately from each source. The spectrum of an input amplitude-modulated signal is nonlinearly related to the spectrum at the output. Aim. The conversion of the current spectrum under supplying an amplitude-modulated voltage to an active non-linear element with a non-linear current-voltage characteristic is considered. Materials and methods. In the analysis of the spectral transformation, a power approximation of the current-voltage characteristic in the form of a polynomial of the third degree with trigonometric functions is used. In the examples, spectrum transformations for a mono signal, amplitude-modulated signal, and beats are considered. Application of amplitude modulation methods is essential for transferring the spectrum of the signal to the low frequency region. Results. A graphical representation of the dependence of the current function on time for an AM signal and beats, as well as their spectral representation, is given. Conclusion. The paper analyzes the transformation of the signal spectrum for the current when applying any, but amplitude-modulated voltage on the ohmic nonlinear element. The carrier signal is represented as a harmonic trigonometric function of the cosine of the current time. However, signal spectrum conversion has not related with detection.
Бесплатно
Краткое сообщение
In the condition of increased competition, the main task is strategic enterprise management. In this article based on the degree perfection increase of technical systems, the technique of identifying strategic directions related to the development of the enterprise is proposed. A universal approach to determining development goals of industrial enterprises: continuous increase of the perfection degree is formulated. Various strategies for the development of industrial enterprises are considered, and recommendations for its applying for different types of enterprises are provided.
Бесплатно
Study of the mechanism of action of modulated UHF signal on a spherical non-ideal dielectric model
Статья научная
The work belongs to the field of electrodynamics and electromagnetic compatibility. The conversion of microwave radiation passing through a non-ideal dielectric and its concentration in the dielectric region is analyzed. The results of the study of the mechanism of modulated microwave radiation when exposed to a spherical non-ideal dielectric are presented. The mathematical apparatus on the basis of which modeling was carried out is given. The study was carried out by means of computer simulation in CAD CST Studio Suite that combines a rich set of tools for low and high frequency modelling and solution of problems of electrodynamics. The effect of microwave radiation focusing when exposed to a spherical non-ideal dielectric of the modulation type and depth is studied. The results of the influence of frequency-amplitude-pulse-modulated microwave signals on a spherical non-ideal dielectric were obtained. It is shown that the radiation is linearly frequency-modulated signal, there is a concentration of radiation to a small area of the dielectric, put forward the theory on the ability to control the location of concentration of the radiation by changing its parameters. The paper presents the parameters of the spherical non-ideal dielectric, such as dielectric permittivity, conductivity, loss tangent, etc. are the parameters of the modulated microwave signals. The practical significance of the obtained results is explained.
Бесплатно
Survey of primary methods of fingerprint feature extraction
Краткое сообщение
Proving the identity of the individual today is an urgent need in many areas, including social security, financial, criminal and other fields. Biometrics is interested in identifying individuals through personality traits, eye color, fingerprints, height, facial appearance, and signature. Image processing technology supports most of the techniques used in biometrics, by improving images and matching images, to identify the individual identity. Fingerprint recognition is some of the most well-known biometrics, and it the best the used biometric result for confirmation on computer systems. Technic fingerprinting has a great popularity for simplicity of acquisition, the use and approval when compared to other systems. Fingerprint Recognition System consists of four steps: firstly, Image acquisition (image fingerprint) through sensors.Secondly, processing the image so that it obscures the noise that exists, clarifying the hills. Thirdly, Extracting features of injury fingerprints. Fourth, compare the acquired features with features of fingerprint fingerprints in databases. The aim of this paper is to present the latest research in the applications of fingerprint recognition systems.
Бесплатно
