Keywords: desalination, current-voltage curve, electrodialysis, nernst-Planck-Poisson and Navier-Stokes equations, gauss-Ostrogradskii law, numerical methods, membrane systems, ion exchange membrane, desalination channel
The current-voltage characteristic is one of the most significant characteristics of salt ion transport in membrane systems. To date, there are only experimental studies of current-voltage characteristics that show complex, unsteady, unstable behavior. This is one of the reasons why there are no studies of theoretical current-voltage characteristics, another reason is mathematical and computational difficulties. In this article is derived using the Gauss-Ostrogradskii law and analyzes the formula for calculating the theoretical current-voltage characteristic for a three-dimensional desalination channel of an electrodialysis apparatus in a potentiodynamic mode. It’s shown that this formula is stable with respect to rounding errors in spatial variables, while maintaining the complex non-stationary behavior of the current-voltage characteristic over time. To apply the formulas, it is necessary to calculate the local current density using a mathematical model of the transport of binary salt ions in a three-dimensional desalination channel of an electrodialysis apparatus (EDA), taking into account electroconvection. The main regularities of changes in the current-voltage characteristic are established. It is shown that it qualitatively coincides with the experimental current-voltage characteristic. A small quantitative difference can be explained by the fact that the mathematical model does not take into account the dissociation/recombination reaction of water, gravitational convection and other transport mechanisms and requires separate further studies.
Keywords: desalination, current-voltage curve, electrodialysis, nernst-Planck-Poisson and Navier-Stokes equations, gauss-Ostrogradskii law, numerical methods, membrane systems, ion exchange membrane, desalination channel
In this article, an attempt is made to fill the gap in the filtering properties description of materials with a rigid layer structure, for example, perforated foil. A feature of the filtration process with such partitions is that the sediment layer is formed fairly quickly and only on the surface of the partition. Therefore, the properties of the partition are of secondary importance, and, thereafter, the main filter layer is the layer of deposited particles which thickness and porosity are continuously changing. The model is designed to predict the dynamics of changes in the concentration of solid particles in the gas stream at the outlet of the filter. In development of the model, assumptions were made about the duration constancy of the inter-regeneration period, the regeneration efficiency, the specific gas load and the input concentration of solid particles. Making a conclusion about the dominant role in the formation of the sieve effect sediment, the conditions and parameters of the dispersed phase particles capture mechanism were determined. Considering that the number and size of pores constantly change during the filtration process, the effective porosity parameter is introduced as a simplification, which allows to obtain a dependence for finding the concentration of solid particles at the outlet of the filter. Experiments have confirmed the accepted principles and the adequacy of the model. In the future, the presented model can be used to optimize the operation of existing filters using rigid porous partitions, as well as to develop new filter designs and their regeneration systems.
Keywords: mathematical modeling, differential equations, filtration, rigid filter partitions, solid particles, gas purification efficiency
The importance of survival analysis in medical problems has led to development of a variety of approaches to modeling the survival function. Models built with various machine learning methods have strengths and weaknesses in terms of differential performance and calibration capabilities, but no model is most suitable for all datasets or even all-time horizons within a single dataset. The relevance of the research is due to the fact that basic models and ensemble approaches do not always make it possible to build a proper survival model for different time horizons. Because of that, this article aims to outline the application of a new approach that combines various basic models to create a reliable survival function, providing opportunities for fine tuning and having good discriminant characteristics in different time horizons. During the course of the study, six basic models for analyzing survival after myocardial infarction were described: nonparametric methods (Cox proportional hazards model, Cox proportional hazards model using ridge regression), parametric models (logistic normal distribution model, logistic exponential distribution model, Weibull distribution method) and ensemble model (random forest). The principal approach to solving this problem is the use of an improved method – temporal quilting. In this study, the aforementioned approach is compared to basic methods in relation to accuracy and assessment of model calibration. The research results have revealed that ‘temporal quilting’ model is the most efficient while random forest model appears to be the least efficient. Since the enhanced approach automatically finds the approximation of the best-suited survival model, it enables clinicians to reduce time spent on the search for one specific survival model for each dataset as well as for each relevant all-time horizon.
Keywords: machine learning, survival analysis, temporal Quilting, bayesian optimization, myocardial infarction
The problem of optimal electrical radioelements placement on the mounting plane of the printed circuit assembly is one of the key ones in ensuring the reliability and quality of the electronic devices being developed. When solving it, a specialist has to work in a space of conflicting indicators, conditions and restrictions. To provide normal thermal conditions, for example, it is necessary to consider the values of the power dissipated by the elements, their operating temperatures, take into account the fact that the components differ in weight and size parameters and characteristics of materials. Similar tasks must be dealt with both when securing the mechanical strength of the developed unit and when addressing the issues of electromagnetic compatibility. These aspects must be regarded at the earliest stages of design as they directly affect the performance of the finished product. The article presents an algorithm for handling the optimization problem of placing elements on a printed circuit board with due regard for the temperature values of the elements and the power dissipated by them, which makes it possible to improve the thermal modes of the device operation without using additional design solutions and forced cooling means. The tool for developing the algorithm was specialized computer-aided design systems, including engineering analysis and calculation tools, as well as the high-level C # programming language. The materials of the article are of practical value for developers of radio-electronic devices, solving the problem of ensuring their reliability and performance characteristics at all stages of the product life cycle.
Keywords: radioelectronic device, printed circuit assembly, element placement algorithm, modeling, optimization, electric radioelement, computer-aided design system, temperature regime, reliability
This work contains the analysis of the existing models for calculating the signal loss level in the radio access network. The relevance of the study is due to the fact that radio access networks are widely used in the modern world by telecommunications operators for communication between subscribers around the globe. This paper analyzes the considered empirical and analytical models and confirms the possibility of their application to calculating signal losses for radio access networks. The results were obtained by analyzing the available models, then by choosing the models for calculation under different conditions (urban, rural, open area) and by performing calculations based on these models. The models of Okamura-Khata, COST231-Khata, Xia-Bertoni were employed to calculate indicators at various frequencies of signal distribution and with consideration to external factors, such as changes in the terrain, the presence of tall buildings, the width of streets, etc. As a result of the calculations, it has been revealed that for urban areas and for short distances, the Xia-Bertoni model is best suited since it has more parameters that are taken into account in the model for the urban environment. For open areas or small towns, simpler models can be used: Okamura-Hata for low frequencies from 150 to 1500 MHz and COST231-Hata for high frequencies from 1500 MHz to 2000 MHz. The results section provides graphs showing the dependency of signal loss on distance and indicating that in urban areas the Xia-Bertoni model can calculate more accurately the signal loss value while providing more positive results. The material of the article is of practical value for works that are based on algorithms for calculating signal loss and enables to see ready-made models for calculations and their results for various conditions accordingly, which eliminates the need to spend time on such studies.
Keywords: radio access networks, loss of radio signal, base station, wireless signal, okamura-Khata, COST231-Khata, xia-Bertoni, signal transmission
The developed information training system contains visual, generalized, structured material on mechanical stability, accident rate as well as ecological and biological features of the main woody plant species used in the landscaping of Donetsk: systematics, biology and ecology, biogeography, representation in the environment of Donetsk, mechanical stability and accident rate, crown shape, crown structure, wind resistance, resistance to anthropogenic factors, critical age in the environment of Donetsk, the presence of a cross-section/core sample in the xylotheque, recommendations for gardeners, landscaping concepts, illustrations. The information system is educational in nature and allows the researcher to quickly and visually familiarize themselves with the ecological and biological features of the growth and development of woody plants in the steppe zone, drawing on the example of the industrial city of Donetsk, as well as with the methodology of monitoring studies to assess the mechanical stability of woody plants, to learn to analyze the dependences of mechanical stability parameters for 18 species of woody plants growing in the Donetsk environment and to find and accurately identify the positive and negative aspects of employing various woody plant species for the purpose of landscaping in an industrial city. At the end of the training, there is an opportunity to evaluate the acquired knowledge and skills through interactive testing for each section. The described information system summarizes the results of Russian and foreign studies on the ecological and biological characteristics of the species presented and supplements them with information about the features of growth, physical and mechanical properties of wood, mechanical resistance to dynamic (wind) and static loads (glaciation, snow sticking, etc.) in a large industrial city. The information system is aimed at high-quality training of future specialists in the field of biology and ecology, contributes to the implementation of the results obtained in the educational process (as a study guide for students and postgraduates of biological universities). It can also be utilized in environment state monitoring and in assessing the accident rate of woody plants.
Keywords: information system, algorithm, distance learning, mechanical stability, ecology of woody plants, tree stability, landscaping concept, selection of species
In the article, errors that occur when using the most common current sources with low output resistance (voltage amplifiers), feeding coils of biological object modification sets by means of a magnetic field are identified with the aid of the proposed modeling methods. To exemplify the operability of the models under consideration, oscillograms of changes in the magnetic field induction time in the coil of the set, when it is powered by a voltage amplifier having a low output resistance, are given. As an alternative, it is suggested to employ a developed and assembled specialized current source with a high output resistance, voltage-controlled (ITUN), designed to work with an inductive load. The magnetic field, generated by the coil of the set, fully corresponds to the current, flowing through it from the current source. The article describes the layout of such current source, as well as a high-speed system for limiting the input signal, which enables the protection of the circuit power elements from overloads that occur when working on an inductive load. As an illustration of the effectiveness of the magnetic field creation method, the oscillograms of the change from the induction time of the magnetic field produced in the coil of the set, when it is powered from the current source layout, are presented. In order to implement the layout of the magnetic set and monitor the state of the magnetic field being measured, a high-speed magnetometer was additionally designed and built, which allows reading data in real time.
Keywords: magnetic set, ITUN, magnetometer, magnetic field, modification of biological objects
Differential diagnosis of focal pancreatic pathology is a complex clinical task. The method of endoscopic ultrasonography is the most informative in the detailed visualization of the pancreatic parenchyma and is used as a clarifying method in the diagnosis of focal pathology of the organ, which is provided by high-resolution images due to the minimal distance of the sensor from the object under study. One of the informative criteria for the differential diagnosis of the pathology under study is the characteristic of the contours of focal formations. The aim of the work was to improve the quality of differential diagnosis of focal pancreatic pathology according to endoscopic ultrasonography based on the analysis of the characteristics of the contours of focal formations with an assessment of their informative value. The results of endoscopic ultrasonography of 109 patients with solid tumors of the pancreas and 40 patients with chronic pancreatitis were analyzed. The endoscopic video system of the Olympus EVIS EXERA II company with the EU-ME1 ultrasound processor was used. Using the developed universal algorithms, the most homogeneous fragments of the region of interest are selected from the primary video materials, on the basis of which a scale of characteristics of the contours of the considered focal pathology is formed. Eight main types of contours corresponding to chronic focal pancreatitis and ductal adenocarcinoma with various degrees of differentiation were identified. The obtained data allowed us to construct a histogram with subsequent statistical analysis of the results, which showed the prospects of the proposed method of differential diagnosis of pancreatitis and oncological diseases and the synthesis decision rules.
Keywords: endoscopic ultrasonography, characteristics of the contours of focal formations of the pancreas, chronic pancreatitis, ductal adenocarcinoma, statistical analysis
The article discusses and substantiates the principle of multi-range images combining and processing based on matrix devices with charge coupling. The developed principle is proposed as an alternative to the software implementation of the task of multi-range images combining and processing. The analysis of existing methods of combining multi-range images is carried out and the insufficiency of these methods in terms of increasing the resulting image information content is confirmed. The method for images combining and processing with a view to enhancing the information content, which is performed by means of digital methods, is considered. The possibility and prospects of the specified problem employment with the aid of discrete-analog systems, namely, the basis of matrix devices with charge coupled, have been affirmed. The principle of a two-stage impact on charge packets, which form image pixels in matrix devices with charge-coupled devices, is suggested with the aim of dividing them in specified proportions, indicated in the digital method, and introducing the necessary division parts into adjacent storage cells. The application simplicity of the procedure for dividing and moving parts of the charge packets by changing the voltages on the phase buses of the matrix device with charge coupling is shown. The transfer characteristic of the charge coupled matrix device in the outlined mode is determined analytically. The coefficient of the transfer characteristic squareness is ascertained.
Keywords: charge coupled matrix device, images, processing, charge packets, charge pack division
In the tasks of metrological synthesis, the task of determining the metrological characteristics of the measuring instrument is set. In modeling, the measuring instrument can be represented as a set of nodes whose parameters affect the measurement result. The case of determining the probability density of the total error of the measurement result for sequentially connected units of the measuring instrument is considered. The identification of the distribution law of the total error is carried out on the basis of a machine experiment. As an example, it is proposed to consider a case combining a constant value of an input quantity for which the error is defined as additive noise composed of independent quantities. A machine experiment is performed to iteratively search for the composition of the distribution laws of random independent quantities of neighboring nodes of the measuring instrument, the result of the composition is compared with the known distribution laws. Two cases of attribution of the law of distribution of the total random variable to the normal law or the law of arbitrary form are indicated. The estimation of the error of the measuring instrument is based on the calculation of probabilistic characteristics based on the found probability distribution density, which makes it possible to use a priori information about each of the nodes of the measuring instrument in the evaluation. It is proposed to consider mathematical expectation, variance and interval probability as characteristics of the accuracy of the identified density of the error distribution of the measurement result.
Keywords: measuring instrument, measurement result error, probability distribution density, composition of distribution laws, simulation modeling, identification of the distribution law
In this article, suggestions are given for modeling the processes of cell separation by the magnitude of magnetic susceptibility. On the basis of the proposed model, an operating separation unit was created, and its description was given. To improve the efficiency of the operating separation unit, in comparison with existing equivalents, design solutions were introduced. It has been experimentally established that a lattice, consisting of rods of soft magnetic steel, which is a spatially periodic polygradient structure, can secrete cells of various magnetic susceptibility when the magnitude of the external magnetic field, applied to this structure, and the constant flow rate of the working medium, pumped through it, change. Additionally, we have also developed a technique for isolating cells with different magnetic susceptibility by means of the operating unit. The derived method makes it possible to acquire "spectra" of the magnetic susceptibility of cell samples. After the calibration of the unit, it is possible to predict the expected results of the cell separation analysis. The efficiency of the devised separator rises with an increase in the number of rows (rods) in the periodic structure. The accuracy of the findings depends on the pumping time. With weak fields, the shutter speed needs to be accelerated. Non-magnetic or weakly magnetic biological cells may remain in the swirl zones. This phenomenon negatively affects the quality of the samples obtained, especially with weak magnetic fields.
Keywords: separator, magnetic field, biocells, magnetic susceptibility, high-gradient magnetic separation, method of biocell separation
The article completes a series of three original publications, related to the modeling of seismic risks in the geological environment in design and construction of critical infrastructure facilities. The preparation of the series is aimed at achieving the goal of finding a quantitative correspondence of seismic risks, calculated according to mathematical models, with seismic impacts, regulated in the Seismic building design code (SP 14.13330.2018). For this purpose, the tasks are solved: in the first article the criteria for choosing test territories are justified, and the territory of Armenia and neighboring states is selected as a test region; in the second - by the example of the test area, an assessment of the probabilistic seismic risk was performed with the help of specially created mathematical models at the regional and local scale levels; in the third - mathematical models and software were developed to determine the compliance of the calculated seismic effects, regulated by the design code with the values of the probabilistic seismic risk, obtained using mathematical modeling. The final article concludes that the prospects for further research are associated with the construction of a new seismic intensity scale of possible earthquakes as a function of the calculated probabilistic seismic risk and the depth of the possible earthquake source, as well as the creation of a special normalization scale that enables to transfer the probabilistic seismic risk, calculated for any region, into intensity as a measure of shaking in points of a single macro seismic scale. The construction of similar scales is highly relevant for the calculated kinematic parameters, currently employed in the design code – peak acceleration, displacement velocity and the actual displacement of the ground.
Keywords: modeling, seismic risk, geological environment, test area, building codes and regulations
The paper discusses the problem of structuring the optimization modeling of the process of adaptation of personnel to digital management in organizational systems. For this purpose, the implementation of the proposed block diagram of digital control is investigated within the framework of the requirements for the efficiency, quality and reliability of a man-machine system. The definition of optimization modeling of the process of adaptation of personnel to innovative activities is given. The need to take into account a number of signs associated with both the features of digital control and the structure of personnel training is shown. Particular attention is paid to the process of team adaptation of personnel using the Aggile concept. Taking into account the selected features, the structuring of the initial data was carried out and the nature of their transformation was proposed to select the optimal variant of the controlled process of adaptation of personnel to activities in the context of digital management of the organizational system. The structuring stages are formalized from the position of the numbering theory by solving the problem of finding the main computable numbering on the set of morphisms built on the original numbering sets. All stages of numbering structuring and transformation are combined within the framework of a single optimization modeling scheme for the process of personnel adaptation to innovation.
Keywords: organizational system, personnel adaptation, optimization modeling, numbering structuring, numerical control
The successful implementation of projects on the creation of automated control systems for special organizational and technical systems largely depends on the quality of the complex requirements presented to them, as well as the completeness and accuracy of their execution in design solutions. A necessary condition for solving these tasks is the creation of a model-language and information-software environment that is uniform for all participants in the development of such systems and the implementation of a software-controlled process for justifying requirements, designing, and implementing the project. It is proposed to use the concepts and methods of model-oriented system and software engineering, ontological models, and visual modeling languages as a conceptual and technological basis for this approach implementation. To implement the software-driven process of developing a set of requirements and design solutions are built and used design patterns created based on the ontology "Quality Model of software and hardware complexes" and UML diagrams of uses, behaviors, and classes. The quality model requirements set consists of the characteristics of requirements set as a whole (completeness, consistency, non-redundancy, systematicity) and the characteristics of individual requirements (internal completeness, accuracy, unambiguity, traceability, verifiability, and modifiability). The quality of the formal models of the criteria set and the design solutions are checked by validating and verifying them in the Neo4j graph database environment using dedicated test queries in the Cypher language.
Keywords: validation and verification, graph models, behavior and class diagrams, quality model, ontologies, quality characteristics
The article presents the description and results of the implementation of regional and local mathematical models, created to address the problem of estimating stresses, deformations and displacements in the geological environment. In the regional model, the main factors, causing the occurrence of stresses, displacements and deformations of the geological environment, are the inhomogeneities of the anomalous gravitational field distribution in isostatic reduction and the features of the Moho surface relief. To describe a local deterministic model, which is employed to estimate the stress-strain state of a three-dimensional elastic space, the displacement equations, solved by the Galerkin method, are utilized. Computer versions of models, provided with digital information, open up fundamentally new opportunities for the construction sector in carrying out the tasks of assessment, analysis and forecasting of the geological environment seismic characteristics. Mathematical models and calculations, obtained with their application, are a reliable basis in the field of design and construction of buildings and structures under difficult geological conditions. Survey work and the construction itself require significant material, technical and financial resources. It is concluded that the use of modern digital technologies for assessing, analyzing and predicting seismic risks reduces unjustified losses and develops the intellectual component of the methods exploited as well as methods of design surveys.
Keywords: construction, computer modeling, geological environment, stress-dynamic state, seismic risk
The article considers the model for solving the problem of seismic risk quantitative correlation, calculated on the basis of modeling, with seismic impacts regulated in the Seismic building design code. The paper is the first part in a series of scientific publications on the subject. For the first time, it substantiates the criteria for selecting test territories, describes the methodology for verifying the adequacy of seismic risk assessment models, characterizes a probabilistic model of energy transitions in a stress-strain geological environment, and presents an approach to evaluating model parameters through the potential energy transformation indicators of the stress-strain geological environment. The content of the other two parts of the series is indicated. Armenia and neighboring states meet the criteria for choosing a region for practical testing of the model: high seismicity, the necessary information base and proven adequacy of the seismic risk model application at all deep levels of the earthquake epicenter locations. The method of the adequacy verification of the seismic risk assessment mathematical model, using the Student's criterion, is examined in detail. It is shown that when estimating the parameters of transitions between states of the model, described by the Kolmogorov equations, it is important to take into account both the influence of regional fields (anomalous gravitational field) and local fields (modern tectonic movements). Thus, a rationale is provided for employing two deterministic models – regional and local - for practical evaluation of stresses and displacements in the geological environment.
Keywords: model, seismic risk, stress-deformed geological environment, test territory, criterion, regional and local geophysical fields
During the operation of machines with computer numerical control (CNC), a fairly large number of parameters are controlled, including the position and parameters of the equipment used, the temperature of the machine components, readings from vibration and force sensors. However, there are a number of parameters that cannot be tracked during the manufacturing process using the machine. One of these parameters is the amount of wear on the cutting tool, which can be measured only during periods of idle time of the machine tool. Tool wear significantly affects the quality of the resulting surface. The operation of the tool with high wear leads to an increase in vibration, noise, additional load on other parts of the machine. To solve the problem of assessing the state of wear of a cutting tool, it makes sense to use the available operational information as an indicator of the amount of wear. The article proposes the implementation of such an approach by assessing the amount of wear of the cutting tool according to the data of vibration of the spindle and cutting forces. To forecast this dependence, it was proposed to use bidirectional networks of long short-term memory, since this type of neural networks is one of the most effective in the problem of processing large time series data. By checking the trained model on a test dataset, it was found that the proposed model makes it possible to determine tool wear with an accuracy of 97.5 %. The proposed approach and model for assessing the wear of the cutting tool can be used as part of control systems for CNC machines.
Keywords: CNC machines, milling, long short-term memory, diagnostic in operation mode, cutting tool wear, vibration, cutting force
This paper considers the possibility of applying a number of game approaches to the analysis of a specific economic situation of interaction between participants in the production process - administration and employees, at the enterprise. At the same time, the goals and preferences of the parties do not coincide, which increases the likelihood of conflict and has a direct impact on the result. The corresponding model reflects the peculiarities of the relationship between the financial and economic interests of the participants. A decision-making mechanism is proposed that allows determining the optimal values of the key resulting indicators and justifying the choice of strategies. The approaches have been implemented both from the point of view of antagonistic games and bimatrix ones, as well as staging and solving a game with nature. The presented methodology also helps to identify and analyze the causes of the conflict of interests of players and to quantify the risk measure of each of them when implementing the chosen strategies. The study showed that the application of game theory methods to assessing the degree of satisfaction of each of the participants can reduce the overall uncertainty when modeling a problem situation and provide a more informed decision-making for each of their stakeholders. At the same time, there are certain limitations in the use of analytical tools of game theory for modeling and analyzing complex intra-organizational relations, therefore, it is advisable to combine these approaches with other management decision-making methods to achieve an optimal result and solve production problems.
Keywords: parties concerned, game theory, interaction, conflict of interest, bimatrix play, hierarchical play, play with nature
The relevance of the study stems from the urgency of protecting cyberspace, which is subjected to total information attacks by malicious codes and destructive content. One of the effective means to ensure the security of global and national cyberspace is the mapping of processes occurring in it, including monitoring and counteraction in the conditions of information confrontation, steadily increasing in the state, corporate and social networks. The main purpose of information maps should be seen as increasing the efficiency of experts' (decision-maker's) work based on resolving the contradiction between the need to obtain objective quantitative estimates of the information map influence on the speed and quality of tasks solved using it and the subjective factors affecting the aforementioned characteristics. In this regard, the paper considers for cartographic methods: speed of problem solving, accuracy of problem solving; labor intensity of building an information map; laboriousness of updating the information map; the amount of new knowledge gained through problem solving. This analyzes the effectiveness of the visualization, including the number of intersections and bends of the graph edges, their total length, shape metrics, dynamic stability, cluster and distance change reliability metrics. The effectiveness of the information map is assessed using a search for publications on "Computer Crime" as an example, including a graphical comparison of the results. The conclusion outlines the prospects for further research on the development of methodologies to assess the effectiveness of information maps of protected cyberspace.
Keywords: information map, visualization efficiency, problem-solving speed, problem-solving accuracy, protected cyberspace, cyberspace cartography
This work presents a model of the temperature dependence of the vibrational redistribution of energy with its own electromagnetic radiation in electronic circuits on MOS transistors. The work was carried out in a new area of technical diagnostics - radiosensory technical diagnostics and authentication, based on the registration of the electrical component of the near field of electro-magnetic radiation induced by the electronic unit itself. In the ISIS circuit simulation program of the Proteus 8 Professional package, using PSpice component models, a key element model is built, based on the methods of nodal potentials, loop currents and the solution of quadratic equations. The calculated parameters of the model were used to obtain numerical signal radio profiles of the electrical component of electromagnetic radiation and their temperature depend-ences. The relationship between the decay time of oscillations and temperature is shown in the form of a simple analytical expression. An experiment was prepared and carried out to deter-mine the temperature of the key node using the presented model. A correlation assessment of the reproducibility of signal radio profiles obtained as a result of modeling and during the exper-iment was carried out. It was found that their mutual correlation is not lower than 0.93, and the error in determining the decay time is not more than 10%, which indicates the correctness of the presented study. A conclusion is made and the possibility of using the results obtained in radio-sensor technical diagnostics is shown when determining the temperature of an electronic unit or for leveling the temperature drift of the signal radio profile.
Keywords: signal radio profile, decay time, electromagnetic radiation, free oscillations, technical diagnostics, temperature dependence
The paper discusses existing solutions in the field of human-machine interfaces to ensure group interaction of ground robots and unmanned aerial vehicles when performing tasks in agriculture and spot farming. Various aspects of the interaction of heterogeneous agricultural robots, namely, unmanned aerial vehicles and ground mobile platforms, are considered using the example of a scenario of automated point fertilization on plantations of columnar apple trees. The criteria for assessing the quality of the human-machine interface for the formulation and implementation of group tasks of agricultural robotics are determined. The most effective of them are highlighted: the average time required for a user to solve a problem using the KLM-GOMS method, an assessment of the system complexity by the method of T. Comber and J. Maltby, the correctness of the task, the frequency of successful completion of the task, the time it takes to complete the task, the degree of awareness of the situation, the number of control actions, the accuracy of the diagnosis of the situation, the time of detection and diagnosis of the situation, the behavior of the controlled technological parameter, the workload, the functional state of the operator. The results obtained can be used to develop strategies for the joint activity of heterogeneous agricultural robots, controlled using intuitive human-machine interfaces.
Keywords: agricultural robots, UAV, human-machine interface, quality assessment criteria, group interaction of robots, spot farming
The article raises questions of stimulating the development of the medical computer-aided design by developing and launching an online store of specialized products and services. The analysis of such a technological phenomenon as the "Application Store" and its impact on the development of basic and related classes of information systems and products of the subject area is carried out. An overview of existing analogues in the field of medical CAD is given. An online store use case diagram is being developed. Key metrics for assessing system performance are identified. A cognitive model of related performance and efficiency indicators of the system is built in the form of a sign oriented graph. The units of measurement and the method for calculating all metrics are determined, as well as business requirements are formed for the components of the online store and related information and automated systems in the digital ecosystem of medical CAD. Based on the cognitive model of system performance indicators, an imitation model is built in the paradigm of system dynamics. Simulations are carried out that lead from hypothetical values of the adopted metrics to target values for the stages of development and launch of an online store. The transition of quantitative connections between the participants of the digital ecosystem of medical CAD systems into qualitative ones is considered as a key result of the work of the projected online store. It is expected to obtain and increase a systemic effect: the interaction of manufacturers and consumers of medical CAD through a specialized online store will lead to the identification of hidden problems and opportunities in the subject area, as well as to overcome previously unsolvable problems and tasks of doctors and patients. The main synergistic effect should be to improve the quality of products and technologies in the field of medical CAD.
Keywords: online store, medical computer-aided design, digital ecosystem, systemic effect, efficiency assessment, directed graph, system dynamics
The article discusses the features of building a decision-making system with multivariate optimization of the structure of digital control of the logistics process. The key feature is the integration of the process of transferring the results of activities of the objects of the organizational system participating in the logistics process, and information exchange between the digital platforms of the control center and objects. The variety of structural relationships between the levels of digital control determines the need to choose the optimal option for two sets of indicators that characterize, on the one hand, the efficiency of movement of material flows, and on the other, the efficiency of information exchange between digital platforms. Based on these features, the components of the decision-making system have been substantiated, which allows, on the basis of the requirements determined by the management center, to choose the optimal structural solution. Since the selection process is carried out on a set of performance indicators, its formalized description is presented in the form of multicriteria optimization problems. In this case, for the algorithmization of decision-making, it is proposed to use a simulation model of a multiphase queuing system, adequate to digital control of the movement of material flows between objects of the organizational system.
Keywords: logistics process, digital control, decision-making system, multivariate optimization, simulation
Despite the great attention paid in modern works to the problems of organizing structural-dynamic monitoring systems, there are still topical issues related to ensuring their reliable functioning in the event of external influences. In this regard, this article is devoted to solving the problem of assessing the process of functioning of structural-dynamic monitoring systems from the point of view of possible changes in its composition and structure under conditions of external influences that affect the performance of the system's functions with the required characteristics. The proposed approach to solving this problem is based on the theory of graphs and discrete optimization methods, which make it possible to represent the process of the system's functioning as two interconnected particular problems: determining the optimal combination of the monitoring object-monitoring tool and bringing information to the end user. For the first particular problem, a multicriteria problem of covering a bipartite dynamic graph with stars is considered and an algorithm for its solution is proposed, and for the second, the application of algorithms with estimates to construct approximate solutions. As a criterion for assessing the upper bounds of changes in the characteristics of the system, at which it performs the assigned tasks in the required volume, it is proposed to use the concept of the radius of stability. On the basis of the analytical expression of the radius of stability, it is shown how to assess the stability of the optimal, according to the given criteria, variant of the composition and structure of the structural-dynamic monitoring system to changes in its characteristics as a result of external influences. The application of the results obtained in existing technologies for constructing structural-dynamic monitoring systems will increase the reliability and stability of the functioning of such systems.
Keywords: monitoring system, dynamic graph, graph coverage, stars, chains, stability radius, multicriteria optimization, structural dynamics, external influences
The geological environment parameters are widely used in the hydrocarbon deposits exploration and study. They store information about the rocks physical characteristics, the location of the reservoirs, the boundaries of the layers separation, etc. The numerical values of the parameters under consideration are obtained by conducting geophysical well logging (GWL), or by recalculating existing logging curves based on known petrophysical laws. Because GWL can be carried out only if there is a drilled well, the environment parameters are often known only in a small near-wellbore space. This makes urgent the task of predicting the geological environment parameters within the entire field. The existing methods for solving this task can be conditionally divided into two groups: using only GWL data; complexly using 3D seismic and GWL data. The first group is effective when there is a dense grid of downhole measurements. The second group shows the best results in the conditions of a sparse irregular grid, however, it requires the seismic data availability within the entire studied field. This paper describes a new method for predicting geological environment parameters based on the GWL data and 3D seismic prospecting combined use. The paper also provides an algorithmic implementation of the new method; ways of optimizing algorithmic implementation are considered.
Keywords: volumetric petrophysical model, geostatistics, kriging, seismic exploration, geological well logging, seismic attribute, optimization
This article considers the issue of ensuring the effective use of proactive control of the functional characteristics of the radar complex, taking into account the technical readiness of hardware and software and the level of training of operators and maintenance personnel. The importance of the human factor contribution in ensuring the combat readiness and effectiveness of the use of the radar complex for its intended purpose is emphasized. As a result of the analysis of the existing methodological apparatus for assessing the level of training of operators and service personnel for the modern proactive management methods implementation, the necessity and ways of improving it are determined based on the competence approach adopted a priori in the Russian Federation. The concepts of the professional competence portrait of the operator and the reference professional competence portrait describing the necessary and sufficient set of competencies required by the operator for timely and effective management and application of the radar complex are introduced. An information model of a professional competence portrait is described, a metric for calculating a quantitative integral assessment of the level of its formation is proposed, which is applicable for software implementation as part of automated training tools. The scheme of application of automated training tools for solving operational tasks of proactive control of the radar complex is presented. The necessity of using Big Data of operational data of the repair and diagnostic complex for detecting signs, determining the causes and eliminating/preventing failures, as well as archival and up-to-date data from automated training facilities on the state of training of operators and maintenance personnel in the process of proactive control of the radar complex is noted. Based on the results obtained, it can be concluded that it is advisable to integrate training facilities and systems of technical and functional control of the radar complex to achieve a given level of probability of performing the tasks of the radar complex according to its intended purpose.
Keywords: proactive management, technical control, artificial intelligence, big Data, educational and training tools, competence approach
In the modern world, there are various means of communication: electronic devices, web and mobile applications (Internet forums, chats, blogs, social networks). As a result, a huge amount of information appears about the users themselves, about their attitude to other people, to events taking place in the world. This information can be useful in modeling the processes occurring in society, predicting the behavior of people. Thus, the methods of collecting and analyzing information contained on the Internet are interesting for research. Information on the Internet is presented in the form of a text in a natural language, therefore it is necessary to use the methods of computational linguistics. For example, let's say we have text. Without reading, is it possible to understand what emotion he carries? You can, for example, classify an emotion into positive and negative. The paper discusses Convolutional Neural Networks, which were originally developed for image processing, but also cope with tasks in the field of automatic word processing and Recurrent Neural Networks, the main difference from traditional ones is the logic of the network operation, in which each neuron interacts with itself.
Keywords: sentiment analysis, processing of notes and comments, information, text, convolutional neural networks, recurrent neural network
To restore the motor functions of the lower extremities in post-stroke patients, it is proposed to use a biotechnical system with a robotic device. The control is based on the analysis and classification of electromyosignals. The robotic device is controlled by a fuzzy control module, which allows maintaining three modes of rehabilitation, selecting and switching them depending on the functional state of the patient, thereby deciding on the optimal rehabilitation program for the current functional state of the patient. The control model includes three fuzzy control modules with the corresponding bases of fuzzy decision rules and it allows you to adapt the rehabilitation procedure to the functional state of the patient. To assess the effectiveness of the proposed method of rehabilitation, the experimental group included 23 patients who underwent exacerbations from 25 days to 5 years, including patients with subacute (<180 days after exacerbation) and chronic (> 180 days after exacerbation) conditions. After a course of rehabilitation by means of a biotechnical system with a fuzzy control module, there is a significant increase in the maxima of the support reaction force Rz on the affected leg in the experimental group in relation to the control group. Accordingly, the amplitude of the front push in the experimental group increased by 62% (120%), the rear push by 58% (115%), while in the control group the amplitude increase was 40% (101%) and 41% (105 %). In this case, distinct maxima of the support reaction component Rz appear on the paretic leg.
Keywords: fuzzy control module, post-stroke patients, robotic device, algorithm, base of fuzzy decision rules
The article describes an algorithm for regulating the quantity of slots in the implementation of the anti-collision protocol Q when it is used in information systems for the international goods transportation. The purpose of the study is to develop and substantiate an algorithm for regulating the number of slots when implementing the anti-collision protocol Q in information systems for international goods transportation. Results. An appropriate algorithm was proposed, which differs from existing solutions in fewer required variables and fewer operations required to calculate the number of slots. This algorithm should help to decrease the time needed to transfer information from RFID tags to information systems for international goods transportation. Upon condition an equal quantity of frames, the proposed algorithm reduces the total number of operations to determine the number of slots that will be required to read a set of RFID tags by 16.7%. The algorithm is applicable due to the fulfillment of the requirement to achieve maximum system efficiency not lower than for existing solutions, which was proved with simulation modeling. Practical significance: the results obtained can be used to ensure the availability of information when information from RFID tags enters the information systems for the international transportation of goods, as state information systems. The results can be used by customs authorities in the development of information support for labeling and traceability systems
Keywords: RFID-technology, RFID-mark, RFID-collision, mark collision, RFID-marking, customs bodies, goods marking, RFID, anticollision protocol
The exploitation of mineral deposits requires their rational use. In order to avoid deterioration of water quality and disruption of hydrodynamic processes of deposits, a unified system of monitoring and management of the process of extraction of natural resources is necessary. In this regard, the task is to develop an automated control system that can analyze the changes taking place and make adjustments to the production parameters. However, modern methods of modeling hydrogeological objects have a number of disadvantages and require serious analysis to obtain reliable modeling results. In the course of the study, the methods of modeling hydrogeological systems implemented at the Kavminvod deposits were considered. The main direction of development was obtained by methods using filtration modeling. Such equations describing the processes of geofiltration as two-dimensional and three-dimensional are considered. The results of the study represent the design and physical parameters of the considered models implemented on hydrogeological objects of the CMS region. The models have an acceptable error determined on the basis of comparing the values of the model experiment with the data obtained on real objects, and therefore it is concluded that they are effective in solving this class of problems. To increase the reliability of the results, it is necessary to take into account the number of layers, their composition, structure and integrity, in addition, to include parameters that take into account their mutual influence.
Keywords: modeling methods, hydrogeological system, geofiltration processes, three-dimensional modeling, system analysis