PNRPU Bulletin. Electrotechnics, Informational Technologies, Control Systems

In the conditions of intensive development of various spheres of activity of the state and society, the use of advanced information technologies becomes one of the most important and often decisive factors that determine the effectiveness of all levels of management. Information technologies hold a strong position in everyday life and in various spheres of government activity. Information systems of various types and purposes are being introduced for processing and analyzing information, forecasting and supporting management decisions making at various levels. The functioning of almost any organization in a varying degree depends on how efficiently and steadily its information system works, how reliably its information resources are protected from various information security threats, one of which is spam. It is worth noting that there have been many attempts to solve the problem of its detection once and for all. Research is ongoing in this subject area constantly. Based on its results, various approaches are proposed and implemented in practice. They are mostly based on the well-proven basic statistical processing of various parameters of emails. At the same time, the content of e-mails is not fully taken into account, which leads to an increase in the number of Type I errors. To address this issue, the authors previously proposed a model of emails that takes into account the content of emails, which often changes depending on the tasks performed by users and their changing information needs. Its key feature is that it operates with data obtained from the original text of emails and converted into a numeric vector. As the parameters of the model of emails that influence the selection of emails test segments, which are a reflection of their distinctive features, the authors identified: the number of numeric codes associated with text characters in the function of converting letters to numeric vector; the step of fetching text characters in the function of converting letters to a numeric vector; sample length (length of the «generator» - the sequence that generates the «gene»). Purpose of the research: to assess the influence of the sample length (length of the «generator» - the sequence that generates the «gene»), which is the email model key parameter, on results of the use of the model in spam detection. Methods: use of decision rules of the implicative type «IF ..., THEN ...». Results: the results of the experiment confirm the correctness and applicability of the email model previously developed by the authors. At the same time, the application of the e-mail model gives the best detection results when the numerical value of the sample length (the length of the «generator» - the sequence generating the «gene») is equal to 1 or 2, which is confirmed by the values of the aggregated assessment measure (the value combining the measures of completeness and accuracy of detection and representing their harmonic mean). When the length of the «generator» is greater than or equal to 3, the detection results deteriorate on average by more than 10 %. The inexpediency of using the «generator» length values greater than or equal to 3 is justified by an unacceptable decrease in the values of the detection completeness and the aggregated assessment measure. Practical relevance: the authors' model of emails and an approach to spam detection allow to highlight the sequences of text characters corresponding to the characteristics of a certain class of emails, and to make the spam detection process individual for the recipient.

The improvement of technologies for the collection and primary processing of secondary non-ferrous metals is a prerequisite for the development of secondary non-ferrous metallurgy and the becoming, of solid waste processing enterprises. One such technology is eddy-current (electrodynamic) separation in a traveling magnetic field. Such separators easily fit into technological lines and are used in the extraction of non-ferrous metals from various types of metal-containing solid waste (automobile scrap, mixed production and municipal waste, cable and electronic scrap, etc.), as well as in the processing of complex non-ferrous scrap in preparation it to metallurgical processes. The article discusses eddy-current separators based on linear inductors. The Installation consists of a conveyor that moves the materials to be separated and an inductor located under the conveyor belt. Modeling the interaction between a magnetic field and conductive particles is complicated by the existence of various electromagnetic and mechanical (gravitational and friction) forces. Purpose: Development of a mathematical model taking into account the action of various forces on particles and an assessment of ways to increase the efficiency of eddy-current separation. Results: A mathematical model for studying an eddy-current separator based on a linear induction machine is presented. Separation is the result of combined actions of different forces on conductive particles. Consequently, an important part of the separator model is the equations for the combined electromagnetic and mechanical action. The model takes into account the movement of conductive particles in two directions: the transfer of particles along the conveyor belt and lateral movement under the influence of electromagnetic forces. The results of the study of a prototype of an eddy-current separator based on linear inductors, constructed in the laboratory of the Department of Electrical Engineering and Electrotechnological Systems of the Ural Federal University, are described. The possibility of improving the performance of the separator due to the use of linear induction machines with opposite direction travelling magnetic fields is shown. Calculation results are consistent with industrial test data.

Modern technological process is impossible to imagine without automatic control systems. With proper use of such systems, it is possible to obtain optimal operating parameters, both for a particular node and for the technological process as a whole. In the conditions of modern market relations and fierce competition, the problem of high quality of products with minimal production costs becomes especially urgent. This makes it necessary to create high-precision, fast and reliable control of processes and devices. Purpose: development of an adaptive fuzzy control system for the rectification process of a recycled solvent (isoprene-isopentane-toluene fraction) using the Fuzzy Logic Toolbox expansion package for various critical operating situations. The main critical parameters included are the following: high or low temperature, high or low pressure, and high or low hydrocarbon level in the column bottom. Methods: to solve the problem of choosing a critical situation, a fuzzy controller for condition assessmentwas developed. This controller has two resulting outputs regarding the possible critical situations. The first output requires the need to use hot water as a heating agent. The second output requires the need to use steam as a heating agent. Results: depending on the output of the fuzzy controller for condition assessment, one of the two subsequent controllers is switched on. These were in advance set to certain values of input variables. Practical relevance: the proposed method for controlling the process of continuous rectification of isoprene-isopentane-toluene fraction in a tray-type column will allowto timely detect the critical situations during system operation and take necessary measures to remove them, which ultimately will improve the product quality, increase plant capacity and save energy.

The article deals with the problem of modeling the thermal zone in the process of electron-beam welding, which is widely used at machine-building enterprises of the Russian Federation. The relevance of this study is due to the complexity of the selection of an effective set of technological parameters for titanium alloy products. The use of mathematical modeling methods can significantly reduce time, labor, and economic costs for improving and also working out existing technologies. At the same time, the use of dynamically changing thermophysical parameters in the process of modeling helps to increase the accuracy of modeling. Purpose of the study: improving the efficiency and quality of mathematical modeling of the temperature field. Methods: the approach proposed in the article for the use of dynamically changing thermophysical parameters uses the methods of regression analysis, which make it possible to restore the values of such parameters for alloys of products in the process of modeling. The following widely used approximation methods were used: linear, quadratic, cubic, exponential, logarithmic, which allow restoring the dependence of the missing values of thermophysical parameters depending on the temperature of the material. To simulate the distribution of the temperature field, the apparatus of the theory of welding processes is used, on the basis of which the computational relations are realized. Results: In the process of experimental studies of the application of the approach proposed in the work, the simulation of energy distribution during electron-beam welding of a product element made of VT-14 titanium alloy was carried out. The use of dynamically changing thermophysical parameters of the product made it possible to obtain the energy distribution function in the heating zone in a more natural form, when heating of colder zones does not give a high distribution of heat to adjacent areas. Discussion: the results obtained can be used to improve the quality of the welded joint, as well as to ensure the repeatability of the technological process of electron beam welding.

The growing impact of the information sphere on social life challenges the State with a new direction of activity - the implementation of the information function. To implement this function at the internal level, public authorities create state information systems that are used for processing sensitive data. Therefore ensuring information security when processing data in these systems becomes crucial for the state. Purpose: to counter targeted attacks on cloud computing based information systems on the example of private cloud environment. Methods: this study offers an approach to recognizing attacks on state information systems based on functional analysis methods, pattern recognition theory, and the use of risk assessment methods to reduce the number of false positives. Results: aт approach for attacks’ recognition for private cloud environment based on the pattern recognition theory is proposed. The attack is presented as a pattern that must be recognized during the processes of storing, processing, and transferring information in the guest operating system. To detect an attack, it is necessary to determine the probability of matching a certain class of attacks of a set of attacks to each object from the set of attacks based on the available description and information about the attacks’ classes. Then functions to estimate the proximity (for example, Chebyshev distance) of the detected attack object to a known attack class can be applied. In addition to the proposed method, an approach based on the information risk assessment is proposed to reduce the number of false positives. The essence of the approach is that the signs of attacks are ranked by the level of influence on certain components of an information system. Each of the ranking criteria is ranked with a certain number of points, which assesses whether a particular criterion is related to the fact of the attack implementation. If the sum of points exceeds a certain threshold, then a fact of attack recognition can be registered. Practical relevance: the results can be used to create intrusion detection systems for information and telecommunications systems, including those used when implementing the State’s information function.

Modern systems are vulnerable to threats because of insufficient assessment of the information security effectiveness. This problem characterizes a breach of the information security management process. It is obvious that the lack of a scientific base of methods and assessment algorithms leads to a violation of protection effectiveness. From the standpoint of business impact, the cost-benefit assessment identifies vulnerable indicators, ensuring the reliability of business processes. Therefore, the scientific task is to ensure the process of information security system functioning by assessing economic efficiency. Purpose: development of an up-to-date method for assessing the economic efficiency of an information security system based on model of economically efficient functioning of the system. Methods: analytical and mathematical models of the linguistic description of an effective protection system determine the assessment of economic efficiency. The method based on it consists 9 consecutive stages of assessment. It implements an organizational and mathematical algorithm based on the hierarchy analysis method. Results: the article presents the results of designing a linguistic model in the form of an undirected graph. It selects subsystems, requirements and information security tools to ensure the maximal economic efficiency of the system. Graph carries out a preliminary calculation of the assessing economic efficiency results. Article provides the development of the assessment method connected with economical model. The developed method tested on a real protected object. Economical method calculated indicators of the information security system efficiency. As a result, method calculates economic efficiency data, the degree of risk for information system, as well as model parameters. It gives a verbal description of the effective security system parameters including the protection coefficient. Practical relevance: the developed method tested and applied in the framework of improving the performance of the security system at the facility based on commercial enterprise in Perm Krai. The article also provides recommendations of using the method in organizational measures for information security. Moreover, the authors offered the ways of implementation an economic efficiency assessment in the form of a multi-criteria approach.