Informatics, computer technology and management. Рубрика в журнале - Siberian Aerospace Journal
Errors reduction while locating objects of the radio navigation system
Статья научная
The present research considers a method for improving the accuracy of the dead reckoning position of a board station based on signals from the ground-based radio navigation systems. In the radio navigation sys-tem, grounded on the signal emitted by the base fixed stations, the slave fixed stations receive signals deter-mining the moments of their arrival relative to their own time scales. On the other hand, based on the radio frequency emitting signals by the slave fixed stations, the base fixed stations receive signals defining the moments of their arrival relative to their own time scale. According to the measured moments of radio emit-ted signal arrival, time corrections are calculated to the time scales of the slave fixed stations relative to the base fixed station. Since the time correction is calculated for a time of no more than 10 seconds, a random components are excluded due to the variability of the propagation velocity of the surface electromagnetic wave due to the variability of the environmental parameters and the parameters of the near-surface layer of the electromagnetic wave propagation area. If the calculated value of the time correction of the duration of the clock interval of the generated signal is exceeded, the moment correction (up to a clock) of the formation of the modulating code of the signal emitted by the slave fixed station is performed and the calculated value of the time correction is improved by the value of the previously corrected clock duration. The corrected values of the time corrections (pre-coded) are transmitted to each of the slave fixed stations as a part of their navigation signals. The navigation information consumer receives the radio navigation signals emitted by the fixed stations, through decoding, a consumer highlights information about the mismatch of time scales from the signals of the fixed stations and measures the radio navigation parameters with heightened accura-cy due to compensation for the error of the out-of-sync radiation signals of the slave fixed stations of the radio navigation system.
Бесплатно
Статья научная
A lot of sets of subjects and objects in biology, industry, management can be divided into a number of classes, each of which corresponds to a certain distribution component. When analyzing a mixture of distributions, it is necessary to estimate its parameters (task 1) and to assess the correspondence of empirical and theoretical distribution functions (task 2). To solve the first problem, numerical algorithms that implement the method of moments and the maximum likelihood method are used. In this paper, the problem of estimating the distribution parameters is solved by minimizing the goodness measure by the Quasi-Newton method. The second problem is solved by comparing the empirical and theoretical distribution functions by one or several statistical goodness measures. Statistics of the distribution of these measures depends on the sample size, the method of forming data and estimating distribution parameters. The paper examines the goodness measure between Frocini and omega-square (Kramer – Mises – Smirnov). The evaluation of the statistics of the goodness measure was carried out by the simulation method based on the results of 50000 statistical tests. In each of the tests, the distribution parameters were estimated by minimizing the calculated value of the corresponding goodness measure. The results of simulation modeling allow estimating the statistics of the parameters of a mixture of distributions. The results of solving the considered problems for a mixture of two normal distributions of size 240 are presented.
Бесплатно
Estimation of the number of aperiodic words
Статья научная
In 1902 W. Burnside raised the issue of local finiteness of groups, all elements of which are of finite order. The first negative answer was obtained in 1968 in the article by by P.S. Novikov and S.I. Adian. Finiteness of the free Burnside group of period n was established for n = 2, n = 3 (W. Burnside), n = 4 (W. Burnside, I. N. Sanov), n = 6 (M. Hall). The proof of infinity of this group for odd n ≥ 4381 was given in the article by P. S. Novikov and S. I. Adian (1967); for odd n ≥ 665 in the monograph by S. I. Adian (1975). In relation with these results we consider the set of m-aperiodic words. Word is called l-aperiodic if there are no non-empty subwords of the form Yl in it. In the monograph by S. I. Adian (1975) the proof of S. E. Arshon (1937) of the fact that in the two-letters alphabet there is an infinite set of arbitrarily long 3-aperiodic words was shown. In the A.Yu. Olshansky’s monograph (1989) the theorem on the infinity of the set of 6-aperiodic words was proved, and a lower bound function for the number of words of a given length was obtained. Our aim is to get an estimate for the function ()fn of the number of m-aperiodic words of the length n in the two-letters alphabet. The results can be applied when encoding information in space communications.
Бесплатно
Статья научная
In this paper the approach for external boundary of pole localization region formulation for transfer function with interval-given parameters is proposed. The boundary is formulated as analytic piecewise function of characteristic polynomial parameters of the given transfer function. Analytic formulation of external boundary of poles localization region allows to reduce computations since existing methods require iterative numeric calculations of characteristic equation roots with fixed step size for edges mapping or full interval root locus mapping as well. Formulated boundary allows to clearly describe system behavior and calculate variation ranges of performance indexes. In addition, piecewise function that constrains gives new opportunities for parametric controller synthesis for systems introduced by transfer functions with interval-given parameters. The results can find its practical application in aerospace engineering problems of mathematical analysis and synthesis for highly-precise systems of self-direction missiles. In the research the boundary formulation is performed for third order transfer function. Transfer function order was chosen due to the fact that many physical systems and objects can be described mathematically with the third order transfer function, e.g. model of missile target-seeking head with gyro stabilized drive is described with this model. The research was performed on the basis of the following step sequence: firstly, analytical solving of cubic equation applying Cardano’s formula; secondly, interval root locus edges functions obtaining, next external vertexes set obtaining and, finally, external border formulation and plotting.
Бесплатно
Generalized equivalent strength conditions in the calculations of composite bodies
Статья научная
Structures with an inhomogeneous regular structure (plates, beams, shells) are widely used in engineering, especially in aviation and rocket and space. It is important to know the solution error in the strength elastic calculations for composite structures using the finite element method (FEM),. To analyze the error of the solution, it is necessary to use a sequence of approximate solutions constructed according to the FEM using the grinding procedure for basic discrete models that take into account the non-homogeneous, micro-homogeneous structure of structures (bodies) within the micro-approach. The implementation of the grinding procedure for basic models requires large computer resources. This paper deals with the method of equivalent strength conditions (MESC) for testing the static strength of elastic bodies with an inhomogeneous regular structure, for which sets of different loads are given. According to the MESC, the calculation of the strength of a composite body for which the loading is set is reduced to the calculation of the strength of an isotropic homogeneous body (having the same loading as a composite body) using equivalent strength conditions. In the numerical implementation of the MESC, adjusted equivalent strength conditions are used, which take into account the error of approximate solutions. Here, the MESC is implemented on the basis of the FEM. If a set of different loads is specified for a composite body, then generalized equivalent strength conditions are applied in this case. The procedure for constructing generalized equivalent strength conditions is shown. The calculation of the strength of composite bodies according to the MESC using multigrid finite elements requires 3 6 10 ÷ 10 times less computer memory than a similar calculation using crushed basic models of composite bodies. The given example of calculating the strength of a composite beam, for which a number of loads is set with MESC using generalized equivalent strength conditions shows its high efficiency.
Бесплатно
Статья научная
The purpose of the study is to develop a technological process mathematical model of creating permanent joints of dissimilar materials based on electron-beam welding using machine learning algorithms. Each of the connected elements is a responsible unit of the complex device, due to this fact, strict criteria are set for the quality of the welded joint. In essence, the set task is a regression task. There are many algorithms suitable for solving the regression problem. However, often the use of one algorithm does not provide sufficient accuracy of the result. One way to solve this problem is to develop a composition of algorithms to compensate for the prob-lems of each of them. One of the most effective and potent compositional algorithms is the gradient boosting al-gorithm. This algorithm use will improve the quality of the regression model. The proposed model will allow the technologist to set the process parameters and to get an assessment of the final product quality, as well as by setting input and output values. The use of assessment methods and forecasting will reduce the time and labor costs of searching, developing and adjusting the process. A description of the gradient boosting algorithm is given, as well as an analysis of the applicability of this algorithm to the model and a conclusion regarding the areas of its applicability and the reliability of the forecasts obtained by its direct use. In addition, we consider the process of direct model training based on the data obtained as part of search experiments to improve the quality of final product. The results of the applicability analysis allow us to judge the admissibility of using the proposed method for processes that have similar statistical dependencies. The application of the proposed ap-proach will make it possible to support the adoption of technological decisions by specialists in electron-beam welding during the development of the technological process and when new types of products are put into pro-duction.
Бесплатно
Статья научная
An artillery shot is a complex gas and thermodynamic process of rapidly converting the chemical energy of gunpowder into heat, and then into mechanical work of moving the projectile and the recoil parts of the artillery gun. A distinctive feature of the use of aviation artillery weapons is the short time during which firing from an aircraft at a target is possible, which requires the production of not one artillery shot, but the firing of the maximum number of shells with minimal interruptions between bursts of shots. An analysis of the existing physical concepts of the processes occurring in a small-caliber artillery barrel (hereinafter referred to as the barrel) makes it possible to single out the main quantitative characteristic of the temperature state that affects the quality of the functioning of aviation artillery weapons – the temperature field of the barrel. The temperature field, high in level and gradients, formed in the barrel wall during firing, bursts and series of shots, has a significant impact on the reduction in the tactical, technical and operational characteristics of aviation artillery weapons. Therefore, the problem of synthesizing a mathematical model of thermophysical loading of a wellbore (hereinafter referred to as the model if it is clear from the context of material presentation that we are talking about the developed model) and the definition of the temperature field is of great importance for solving a number of practical applications. These include: assessment of bore wear depending on heating; analysis of the thermal strength of the barrel material; analysis of the conditions of projectile guidance along the bore and cartridge case extraction during firing; evaluation of various ways and methods of artificial cooling of shafts; determination of the safety of aviation artillery weapons by eliminating the event of self-activation of a thermally loaded cartridge located in a barrel heated by firing; ensuring the conditions for maintaining the operability of fuses, etc. At the same time, an adequate calculation of non-stationary heat transfer in the bore is difficult, due to the incomplete reliability of the initial data and the dynamics of fast processes in the use of aviation artillery weapons. The aim of the work is to improve mathematical tools that describe the thermodynamic states of the barrel based on the basic functional dependencies of internal ballistics and a dispersed combination of heat transfer methods and finite differences. Numerous and comprehensive testing of the synthesized model, comparison of the calculation results with the data of the classical theory, self-similar solutions and experimental data confirmed the reliability and predetermined the sufficient suitability of the model for its intended use as the objects of research become more complex.
Бесплатно
Improvement of the construction technique of substitution blocks for symmetric encryption algorithms
Статья научная
As it is known, block symmetric encryption algorithms are widely used to ensure information confidentiality. The resistance of encryption algorithms to the most common types of cryptanalysis is determined the quality of the blocks of substitutions. In the present work, the development of a methodology for constructing substitution blocks is being continued. In the first approach, Boolean functions with given cryptographic properties are used as component functions of substitution blocks. Previously, one of the authors proposed a reasonable methodology for the phased selection of Boolean functions for construction block. In this paper, in addition to such cryptographic properties of Boolean functions, such as: balance, possessing a strict avalanche effect, possessing correlation immunity, for the first time the nonlinearity distances of the first and second orders of Boolean functions are considered simultaneously. A study of the full set of Boolean functions of four variables was conducted. The result of it is the optimal set of Boolean functions for building substitution blocks when encrypted with the GOST 28147-89 algorithm. In the second approach, the substitution block are determined by an irreducible polynomial over the Galois field, such a scheme, used in the Rijndael encryption algorithm, is considered to be strong. The growth of calculating power of the computer necessitates an increase of the cryptographic strength of encryption algorithms. The authors have proposed substitution blocks for each round of the Rijndael scheme, based on different irreducible polynomials. A study of compositions representing a different combination of specially selected irreducible polynomials for ten rounds was carried out and the optimal set of polynomials with the best values of the encryption quality indicators by the Rijndael scheme was obtained.
Бесплатно
Increasing software reliability of a distributed control systems
Статья научная
The article considers a method of assessing and improving main parameters of the computer network efficiency. Reliability is the main criteria for ensuring the required performance of distributed control systems. To improve reliability of the computer network hardware and software redundancy are used. Software redundancy requires new versions to be developed for software modules in which failures are likely to occur. The article considers the N-version programming and recovery block as methods of introducing software redundancy and, taking the need to develop multiple versions of the same software module into account, estimates the costs of network software development. To implement the proposed approach article presents mathematical reliability model that takes into consideration the architecture of a computer network software and the labor costs that its development is going to require. This model becomes a basis for a software created to research computer network software reliability, which allows finding the dependence of network software reliability on the number of one of its software module versions. Comparison of the dynamics changes of reliability indicators and labor intensity of software development indicated a sufficient amount of software module versions that need to be developed. The article concludes by pointing out the importance of determining the labor intensity of network software development and of its usage in the design of a computer networks in which reliability is increased through software redundancy.
Бесплатно
Increasing the period of active use of on-board electronic equipment of spacecraft
Статья научная
For electronic equipment of space systems, and primarily memory devices, the task of protection from the effects of ionizing cosmic radiation and other external factors that distort stored and processed information is relevant. This paper proposes a holographic coding method that allows to restore information in the event of a large number of errors. The method is based on recording into memory, instead of the original digital hologram data, a virtual digital object corresponding to a data block. The divisibility property of a hologram is used, which makes it possible to reconstruct a recorded data block from its fragment. The achieved level of noise immunity is determined by the size of the hologram. For an 8-bit data block, recording a 256-bit hologram provides information recovery if 75 % of the recorded hologram is lost. The developed decoder corrects a package of dependent (grouping) errors that distort all bits of the hologram. The number of random independent errors that the decoder corrects can be up to 40 % of the recorded information. The information storage system, resistant to ionizing radiation, is a memory array of increased capacity, taking into account the selected redundancy factor, and a memory controller that performs holographic encoding when recording information and decoding with automatic error correction when reading information. The operating algorithm of the controller itself can be implemented in the form of a programmable logic integrated circuit, or stored in a read-only memory device that is not affected by ionizing radiation.
Бесплатно
Infrastructure for collecting data and simulating security threats in the internet of things network
Статья научная
The implementation of the internet of things technologies in the rocket-space industry requires increased security measures for information and communication processes. Existing intrusion detection systems are unable to take into account the heterogeneity of the network structure and the scale of information circulating between devices. To solve this problem, intrusion detection systems use an anomaly method, which requires a large number of representative data sets. The authors have reviewed public datasets that can be used to build an anomaly detection system. They contain information from artificial simulation medium or isolated environments with simulated devices, include examples that are not directly related to the internet of things, and do not take into account the dynamic nature of traffic changes. In this paper, we present a new infrastructure that will avoid these drawbacks. It collects data on the functioning of a real Internet of Things network and allows testing its stability to typical attacks. We use the MQTT (message queuing telemetry transport) application protocol and software platforms that support information interaction based on the publisher-subscriber pattern. The infrastructure contains devices that monitor technological rooms with telecommunications equipment, brokers with various security policy set-tings, applications for data control and analysis, software agents for collecting network traffic and threat simulators that perform attacks on network nodes from single sources or in a distributed environment. Researchers will be able to use the data collected in the infrastructure for cybersecurity analysis to create reliable IoT-based solutions needed to implement this technology in knowledge-intensive space systems production.
Бесплатно
Статья научная
The possibilities of creating an innovative educational and scientific center for monitoring forest resources in Siberia on the basis of the Department of Space Facilities and Technologies of the Reshetnev Siberian State University of Science and Technology are discussed, with the aim of training highly qualified engineering personnel and conducting promising scientific research in the field of monitoring, modeling, forecasting and management of forest resources. Methodological solutions and algorithms for threedimensional modeling of forest structure and dynamics based on laser scanning data, digital aerial and space photography are proposed. These methods contribute to operational monitoring and can significantly reduce the cost of monitoring the condition and use of forest resources over the vast territory of Siberia. Remote sensing data is presented in the form of a geotransformed database and digital photo map, compatible in formats with computer-aided design systems and with the main geographic information systems – ArcView, ArcINFO, MapINFO. The innovative monitoring center will be used for operational state control and monitoring of forest management, the state of forest lands, forest management and forest inventory, solving problems of ecology and environmental management, geoecology, formation of a forest resource inventory, aerospace methods for studying natural resources and territories, information technology. Solving these problems will allow for the training of highly qualified specialists. The center's specialists plan to create information technologies for remote sensing of natural objects with the aim of import substitution of foreign software products. The main scientific directions of the created center: development and research of methods for system analysis of large-scale multidimensional remote sensing data based on nonparametric decision-making algorithms and parallel computing technologies; testing hypotheses about the distributions of large-volume remote sensing data based on nonparametric nuclear-type pattern recognition algorithms; detection of compact groups of large-volume remote sensing data corresponding to unimodal fragments of the joint probability density of multivariate random variables.
Бесплатно
Статья научная
Academician Mikhail Fedorovich Reshetnev is one of the outstanding scientists, designers and production organizers who stood at the origins of the development of rocket and space technology in our country and made a significant contribution to domestic and world cosmonautics. 2024 marks the 100th anniversary of his birth and the 60th anniversary of the first launch of the Kosmos-3 launch vehicle (LV), created under his leadership in the Krasnoyarsk Territory. The article discusses the main stages of design, development work, flight design tests and the launch of mass production of the rocket. It is noted that the creation of the PH was carried out mainly at the production base of the Krasnoyarsk Machine-Building Plant (Krasmash). The most important events related to the organization of the OKB-1 branch, which was then transformed into an independent OKB, are described in chronological order. The role of M. F. Reshetnev’s personality is shown. Reshetnev in solving complex scientific, technical, organizational and production problems of mastering new technology in the Siberian region, remote from the rocket, space and scientific centers of the country. Information is provided on innovative technical solutions developed under the guidance of M. F. Reshetnev during the creation of the Kosmos-3 launch vehicle and its subsequent modification. It is noted that M. F. Reshetnev in his scientific and technical activities constantly received the support of S. P. Korolev and M. K. Yangel, successfully cooperated with the largest design organizations headed by V. P. Glushko, A. M. Isaev, V. G. Sergeev and other well-known leaders and specialists of the rocket and space industry.
Бесплатно
Статья научная
Many strategically important sectors of the domestic industry are at the stage of transition to an investment approach to asset management. One of these industries is hydropower, where the current maintenance planning system needs new methods to deliver more efficient results. In general, the planning system for the main equipment (technical impact system) maintenance and repair can be formulated as a scheduling problem. The ant algorithm is of great interest from the point of view of solving the scheduling technical impact problem. Based on the specifics of planning, implementation and factors affecting the maintenance process, a modification of the ant algorithm is proposed. The mathematical description is a methodology for calculating parameters, basic elements of the graph, optimization criteria and constraints. A preparatory stage was also introduced into the solution algorithm, which determines the initial state of the equipment at the vertex K0. The functional model of the technical impact planning process presented in the article can be used to develop a software package within the framework of an innovative approach to asset management for hydropower companies.
Бесплатно
Статья научная
One of the most effective tools of remote sensing and visualization of underwater surfaces and objects are acoustic devices, in particular side-scan sonars (SSSs). Recently, largely due to the emergence of affordable devices, the geography and scope of application of SSSs has been significantly expanded. Meanwhile, despite certain progress achieved in terms of improving and minimizing the SSS hardware, the software used remains, in general, at a basic level, providing the operator mainly with a simple tool for visualizing benthic environments and data recording for further post-processing. Existing experience in SSS exploitation reveals that the key problem of interpreting acoustic images lies in the physical peculiarities of their acquisition. Arguably, attempts to implement methods of automated interpretation of optical images have no perspective. Hence, the objective of this paper is to provide a theoretical and practical background of SSS data interpretation and processing with the objective of further automation of this process. Taking into account the operating conditions of the SSS, in particular the vast areas of water areas - search zones, this problem is one of the key ones for SSS operators. The problem of automating data processing is directly related to the problem of interpreting remote sensing data, including satellite images, geometric distortion of images caused by the physical characteristics of the device and its operating environment, as well as referencing the obtained data to the satellite coordinate system.
Бесплатно
Library of mathematical functions with parallelism at the operational level in the Pythagor language
Статья научная
At present, developed tools and libraries have been designed for imperative and functional programming languages that provide parallelism through processes or threads. There are other alternative approaches to the organization of parallel computing, one of which is implemented in Pythagor – the language of functional-streaming parallel programming, and involves parallelism at the level of operations. The tools of the Pythagor programming language are actively developing, and the repository of predefined functions is expanding. Many mathematical functions have been designed to provide a developer with no less functionality than the math library math.h of the C programming language. A large part of the mathematical functions have been implemented using the Maclaurin’s series. It is both used as an approach of faster and less accurate calculations, in which a predetermined number of elements of the series is calculated without cycles and recursions with the substitution of pre-calculated coefficients in the function code, and as an approach of less rapid and more accurate calculations, in which the elements of the series are calculated dynamically until the desired accuracy is achieved. The development of a library of mathematical functions of a programming language is an applied algorithmic task already implemented in one way or another for a number of existing programming languages. But in many languages, the implementation of algorithms for mathematical functions is hidden from the user, while modern tools of the Pythagor language support an open repository of functions. Additional interest is the possibility of parallelism at the level of operations in the calculation of mathematical formulas in the Pythagor language.
Бесплатно
Managing a group of objects as a task of system analysis
Статья научная
In this paper, we consider the general statement of the problem of identification and management of a group of objects. A group refers to several objects combined for the manufacture of a product. The main feature is that when managing such systems, it is necessary to change the setting actions for each object. This is due to the fact that today the technological regulations in many cases are wider than they should be for good operating. This is a consequence of the fact that the current production culture (this, in particular, has been shown by the experience of processing data from the technological process for the production of transis-tors at Svetlana) is rather low, which leads to some organizational problems. It is clear that it is necessary to have certain models of objects that naturally differ from each other and can be considered under conditions of both parametric and nonparametric uncertainty. Moreover, there may be cases when an object is considered simultaneously under conditions of both parametric and nonparametric uncertainty over various channels. Now, regarding the delay, due to the fact that the measurement of some variables is carried out in a significantly long-er time interval than the object constant, it is necessary to distinguish the time of measuring technological vari-ables and, in fact, the delay typical to the process itself, taking into account the difference between the channels. This leads to the fact that dynamic processes are essentially forced to be considered as inertialess with delay. Another significant feature is that the components of the output variables are stochastically dependent in ad-vance in an unknown manner. The use of correlation or dispersion relations in this case does not lead to success. A special analysis of T-processes and the ability to simulate such processes are required. In particular, this is one of the tasks of this article. It contains: T-processes, T-models and the corresponding heterogeneous control algorithms. The process of hydrodeparaffinization of diesel fuel is considered according to available data, which can be said a priori that they are incomplete, that is they do not reflect the complex behavior of the pro-cess. From here it follows that these data require replenishment, which today is not carried out for various rea-sons. Thus, the process of hydrodewaxing can be taken to the T-process. Modeling a multidimensional system based on real data has shown that in this problem the presetting effect for different objects should be different. The exception is only the setting actions for the entire complex or group of objects. Modeling was carried out on the basis of T-models considered in the article. It has already been not-ed that these models should not be taken as complete, giving an idea of reality. They will be subject to algorith-mic refinement during further research. The decision is made by the researcher. At this stage that an assessment is given that, under the circumstances, the resulting models and control algorithms can be adopted for use in a production environment. An attempt to use the existing theory of identification and control for the process of hydrodewaxing will inevitably lead to a significant degradation and increase in the cost of a computer system for operating the quality of this process.
Бесплатно
Статья научная
One of the main characteristics of computer appliances for processing real-time information is reliability. The reliability of software is understood as the property of this software to perform specified functions, maintaining its characteristics within the established limits under certain operating conditions. Software reliability is determined by its reliability and recoverability. Reliability of software is a property to maintain its performance when using it for processing information in the information system. The reliability of the software is estimated by the probability of its operation without failures under certain environmental conditions during a given observation period. The development of real-time systems requires a large amount of resources for design and testing. One of the solutions to this problem is mathematical modeling of computer appliances. This allows more flexible design of real-time systems with the specified reliability, taking into account the limitations on price and development time, and also opens the possibility of more flexible optimization of computer appliances for real-time control systems. To develop a mathematical model of the reliability of computer appliance for real-time systems, it is necessary to take into account the provision of a given level of reliability, with reasonable development costs. There are many methods for improving software reliability, but the most promising and effective methods are redundancy, which is achieved using N-version programming. To increase the reliability of the hardware of the computer appliance, it is also necessary to use redundancy and redundancy, which includes multiprocessor and provision of different buses and independent RAM. This paper discusses existing approaches to improving the reliability of hardware and software, proposes a model of reliability of a computer appliance, which is understood as the product of the probability of failure-free operation of hardware and the probability of error-free operation of software. In addition, new formulas are proposed for the steady state probabilities of the hardware states of a multiprocessor computer appliance with heterogeneous processors, which give the same result as the existing ones, but require fewer computations. The paper concludes with a question about the possibility of optimizing the reliability of computer appliances based on the developed model, and indicates optimization methods that can be used to solve this problem.
Бесплатно
Mathematical modeling of autocompensation devices
Статья научная
The article studies the order of developing and describing mathematical models of automatic compensation devices of all-round radar stations. The development of algorithms for spatial processing of signals in radar systems with phased antenna arrays is an important stage in the design of radar stations. This article considers the procedure to create mathematical models of automatic compensation devices that differ in implementation methods, namely: the number of compensation channels, the position of the main and compensation (additional) channels of the radar station (stationary or dynamic), the amplitude-phase distribution of the main and additional antennas, the representation phased antenna array, algorithms for finding the weight vector. The method of computational experiment verifies the adequacy of the operation of the models and the results are comparable with the implemented automatic compensation devices in radar stations. Presented in the form of graphs of the signal at the output of the automatic compensation device as well as the passage of the matched filter, the results of the computational experiment show effectiveness of the algorithm to calculate the weight vector; they permit to visually, quickly and economically compare the efficiency of the automatic compensation devices, depending on the method of their implementation. The article discusses the algorithm for the direct formation of the weight vector and the algorithm for the formation of the weight vector through the inverse correlation whitening matrix. Mathematical models of automatic compensation devices and the results of a computational experiment can be used to train future specialists who develop and operate radar stations.
Бесплатно
Статья научная
The construction of detailed accounting that allows to generate complex analytical reporting is an in-dispensable requirement of a modern financial system. For enterprises of the State Space Corporation “Roskosmos” with custom-made and small-scale production, operating in the conditions of Federal Law No. 275, characterized by a large amount of R&D and a high degree of uncertainty in the process of creat-ing products, this task is a system-forming one. The reporting should contain consistent data in any area of management and accounting at any given time. Along with this, system must provide the flexibility, reliabil-ity and performance inherent in transactional databases. To build information support that satisfies the specified conditions, it is required either to separate OLTP and OLAP data schemes, or to apply special-ized solutions based on the use of structures and techniques optimized for performing OLAP operations in traditional RDBMSs. This article considers the approach to form the multidimensional data in an automat-ed management system for economic tasks, as an effective alternative to complex and expensive BI solu-tions. Unlike many commercial systems, the ASU FEZ does not store redundant data (for example, opera-tional accounting registers in the 1C: Enterprise platform) required to build analytical accounting. The underlying data structures and methods of their processing allow for all types of accounting and have pow-erful tools for constructing analytical reporting. The article proposes algorithms for the operation of the system using the example of building simple OLAP cubes used in real tasks of automating financial and economic activities in ISS JSC for one of the Purchase subsystems. The formalization of these problems is carried out, the mathematical apparatus for constructing multidimensional data models based on infor-mation from a fixed set of normalized tables of a relational database is considered.The examples of SQL queries and outputs are provided. The advantages of using the system in operational management and accounting at the enterprise increasing its operational efficiency are summarized.
Бесплатно
