The most informative methods in diagnostics of retinal pathological conditions are ophthalmoscopy, fluorescence angiography (FAG), optical coherence tomography (OCT) and optical coherence tomography with angiography (OCT-angiography, angio-OCT, OCT-A). This paper describes an algorithm of retinal pathologic focus formation based on optical coherence tomography (OCT) scans. The algorithm allows to create a volumetric model of the pathological focus within clinically significant boundaries by separate segmentation of each of the macular cube scans, extraction of the pathological focus point cloud and its reconstruction into a polygonal 3D model. Certain morphometric parameters extracted from such a model are important for better analysis of retinal pathology. This will allow the ophthalmologist to prescribe the appropriate type and amount of treatment to stabilize and improve visual functions.
Keywords: AMD, OCT, macula, retinal pathology, dot cloud, medicine, computer vision, wet AMD
The article is devoted to the issue of increasing the efficiency of ventilation systems through the use of a new type of air ducts. The main advantage of microperforated textile air ducts is the possibility of supplying fresh air with laminar micro jets to the human breathing zone. The need to adapt the existing methods for calculating the main parameters of jets for the laminar regime is noted. The article presents the results on the development of a mathematical model of a stationary boundary layer for the numerical calculation of the movement and heat and mass transfer of air in a laminar microjet. A discrete analog of the generalized differential equation is derived, on the basis of which a software package is developed that allows one to determine the main parameters of laminar microjets. Verification of the developed software package was carried out, the discrepancy with the known engineering method was less than 3%.
Keywords: mathematical modeling, air exchange, microperforated textile air duct, microperforation, laminar jet, control-volume method, round jet, micro jet
The results of research permissible longitudinal axial and fiber tensions are given for various characteristics of gas distribution and gas consumption systems.
Keywords: polyethylene gas pipeline, longitudinal axial tension, longitudinal fiber tension, gas pipeline deformation, optimal gas pipeline bending radius
The analysis of the foundations of modern cryptographic systems is carried out. Problems of classical cryptography arising in the development of quantum computers are considered. Considered are cryptographic protocols of quantum key distribution, their advantages and disadvantages. The analysis of stands for simulation of quantum key distribution available on the market is carried out. The rationale for the need to develop a training system has been made. The authors have developed a system for modeling and demonstrating quantum cryptographic protocols BB84, B92 and BB84 (4 + 2), intended for a detailed study of the principles of quantum cryptographic protocols in dynamics. The system provides the process of work both in text and graphic form. The developed system fully meets the needs of teaching students modern quantum information security technologies.
Keywords: information security; encryption; quantum cryptography; modeling; education system
The influence of the properties of the base and the holding conditions on the adhesion strength to the base of modified building mortars obtained from dry building mixes with a content of 1-3% of redispersible polymer powders has been investigated. A decrease in the adhesion strength of the modified mortar with a standard concrete base was revealed to an average of 0.45-0.8 relative to normal hardening conditions when maintained at elevated temperatures according to GOST R 56387-2018 and to 0.4-0.55 when cyclically heated to 60 ° C, depending on the properties of cement, type and dosage of RPP. The relative strength of adhesion to granite under the same conditions was 0.3-0.65 and 0.2-0.8, respectively. The adhesion strength of modified mortars during hardening under normal conditions relative to the adhesion strength with a standard concrete base is approximately: with silicate brick from 30 to 50%, with ceramic brick from 65 to 80%, with aerated concrete about 50%, with granite from 9 to 18%. The recommended initial dosage of redispersible polymer powders for dry building mixes for heated floors is 1.5%.
Keywords: modified building mortars, redispersible polymer powder, adhesion strength to the base, bending strength, temperature
A feature of modern construction is the large-scale reconstruction of blocks in the center of large cities. In recent decades, investors have increasingly sought to increase the number of storeys of buildings. However, the construction of high-rise buildings (above 75 m) in the conditions of the current development of the metropolis has a number of problems that can negate all the benefits of placing a real estate object in the central districts of the city. The greatest problems are identified already at the design stage of the foundations of high-rise buildings. The article discusses 5 key problems that have the maximum impact on the increase in the cost of construction of high-rise buildings.
Keywords: high-rise buildings, the conditions of the existing development of the metropolis, engineering and geological surveys, dense urban development, geotechnical forecast, geotechnical monitoring, excavation, pile foundations
When designing engineering structures, the efficiency of the engineer’s work is important. The cooperation between individual programs in BIM technology is very important in this aspect, because it significantly speeds up the work and, as a result, the design process is less time-consuming. In the process of designing steel structures, the first stage is the selection of an appropriate structural solution, then numerical calculations of the model together with all assigned load cases and dimensioning of individual elements of the structure in terms of the ultimate and serviceability limit state. After selecting the appropriate sections, you can start working on the detailed drawings of a given structure. When performing numerical calculations and drawings, at least two programs should be used. The article presents the cooperation between the Dlubal RFEM numerical calculation program and the Tekla Structures building structure modeling program on the example of a steel structure floor design.
Keywords: BIM, Dlubal RFEM, Tekla Structures, steel structures, direct import, engineering structures
The effect of redispersible polymer powders on the change in the properties of building mortars after 60 cycles of heating to 60 ° C and cooling is investigated. An increase in the compressive strength from 11 to 27% was revealed at a dosage of RPP from 1 to 3%, and the introduction of an air-entrapping additive into the composition does not contribute to an increase in the compressive strength. A significant increase in the ratio of the tensile strength "flexural tension" has been established/compression", while the tensile strength of building mortars during bending practically does not change with an increase in the dosage of RPP, and the increase in tensile strength during bending occurs to a lesser extent than that of building mortars without RPP, and the presence of an air-entrapping additive contributes to an increase in the tensile strength during bending. A decrease in the initial modulus of elasticity was found almost independently of the dosage of the RPP to values of 0.82 – 0.84, and in the presence of an air-entrapping additive to 0.9 relative to normal hardening conditions. A decrease in the adhesion strength to the concrete base to values of 0.59 – 0.75 relative to normal hardening conditions was revealed. The presence of an air-entrapping additive leads to an increase in the adhesion strength after cyclic heating-cooling by more than 4 times.
Keywords: redispersible polymer powder, adhesion strength, modulus of elasticity, compressive and bending strength, cyclic heating-cooling
The main task in the development and integration of digital automation tools is to increase the efficiency of the enterprise. One of the most relevant areas of integra-tion of such solutions is port activity. The purpose of the current article is to ana-lyze the issues of improving the efficiency of port activities based on intelligent au-tomation tools. The author considers in more detail the solution of the presented problem based on the integration of neural video analytics solutions. The paper us-es theoretical research methods, as well as the results of foreign and domestic scien-tific research. The scientific significance of the work lies in the attempt to systema-tize knowledge about methods of increasing the efficiency of port activities based on intelligent automation tools.
Keywords: port activity, automation, neural video analytics, enterprise, artificial intelligence
Modern research of objects of technology is largely carried out using various software systems. One of such software packages is SolidWorks. It is widely used in industrial enterprises and in research organizations. This complex has extensive libraries of properties of various structural materials. However, they do not represent the properties of all possible combinations of materials with the appropriate hardness. When building a model of a real object, it is necessary to accurately set the properties of materials. This will make it possible to carry out various design calculations with greater accuracy. Previous studies have established that the working part of the turbocharger rotor shaft (made of 40X steel) consists of two layers - surface (hardened) with a hardness of HV 530-570 and internal (not hardened). The values of the physical and mechanical properties of 40X steel with a hardness of HV 530-570 necessary for constructing a rotor shaft model are not available both in the SolidWorks material properties library and in the reference literature. To determine the necessary values of the properties of this material, a series of experiments using a bursting machine was carried out. The experiment was carried out with specially manufactured samples subjected to heat treatment to a hardness of HV 530-570. The data obtained as a result of the experiment were used to construct a model of the turbocharger rotor shaft when assigning the properties of the surface (hardened) layer. This approach makes it possible to obtain results corresponding to real details when carrying out engineering calculations of the constructed models.
Keywords: software package, model, engineering calculation, rotor shaft, surface layer, hardness, sample, tensile machine, physical and mechanical properties, repair
Cast iron occupies one of the most important places among structural materials and is widely used in the manufacture of critical automotive parts.The article examines the possibility of processing gray cast iron by surface plastic deformation (SPD) and the study of its hardening depth in order to control the stress-strain state (SSS) of the surfaces of parts. Modeling is carried out, calculations are close to the real situation, a three-dimensional finite element model is used. The data obtained were analyzed by the least squares method (LSM), graphs were plotted.Also, based on the data obtained, it was found that the relationship between the degree of plastic deformation, the diameter of the indenter and the depth of work hardening is an equation that describes the surface. The carried out researches and the received dependence allow to increase the accuracy of forecasting of results of processing of PPD cast iron.
Keywords: grey iron,plastic deformation, bilinear deformation diagram, indentation depth, spherical indenter
Carrying out work on the inspection of buildings and structures is a set of measures aimed at identifying the actual condition of the object. Since the work on the inspection of buildings includes the work of various specialists, various problems arise related to the incorrect organization of the work. This article is devoted to the identification of the main elements of deadlines, with a reserve for the further development of a tool to reduce the impact on the timing of work.
Keywords: inspection of buildings, interaction of specialists, organization of work, non-destructive methods for determining the strength of concrete, project management
The work is devoted to solving the problem of increasing the efficiency of registration of access of employees of the organization to confidential information. A technique is proposed that allows automating the intellectual activity of employees of the personnel body and the information protection unit to analyze information about an employee in order to determine the possibility of his admission to the protected information. The comparison of the information indicated in the questionnaire submitted by the citizen and the supporting documents is carried out using the Levenstein metric calculated by the Wagner-Fischer algorithm. Predicate logic is used to identify possible grounds for denial of access to confidential information.
Keywords: employee, organization, process, efficiency, confidential information, automation, algorithm, metric, predicate
The growing popularity of the use of group robotics, including swarm robotic systems (SRS), actualizes the issues of information security. Known approaches to detecting malicious behavior of agents or malicious information do not take into account the scalability and decentralization properties of SRS, which does not allow ensuring the integrity of information circulating through communication channels within SRS. In turn, the dissemination of malicious information in the process of distributing tasks between SRS agents initially reduces the efficiency of performing these tasks, that is, an attack is carried out on the very first and most critical stage of the system's functioning. The purpose of this work is to improve the efficiency of the functioning of SRS agents in the presence of malicious agents by developing a method for detecting and counteracting the spread of malicious information. The elements of scientific novelty of this work include the following. As part of solving the problem, a number of specific criteria are proposed that take into account the distribution of tasks in the SRS, as well as a classifier based on an artificial neural network to detect malicious information. To improve the accuracy of detection and counteracting the spread of malicious information in SRS, a modification of the reputation mechanism is proposed. A distinctive feature of the modification is not only the formation of an indicator of the truth of the message information in the process of task distribution, but also the assessment of the influence of malicious agents on the process of forming this indicator. The presented solution is implemented in the form of software in the Python programming language, which can be used in modeling decentralized control systems of SRS.
Keywords: swarm robotic systems, task distribution, artificial neural networks, trust and reputation mechanism
The given review of hygrothermal processes in the processing of grain crops, their features is presented from the standpoint of nanotechnology. It is shown that for the developed nanotechnologies in the production of agricultural products, it is necessary to apply non-traditional methods of process research, which is the method of similarity of the functioning of technical systems (SFTS). This method will allow for the processes of humidification, drying, wet-heat treatment in vacuum conditions to obtain generalized similarity criteria, determine their numerical values and obtain generalized criterion dependences of the intensity of the processes under consideration on the processing parameters. The implementation of the method will allow us to quantitatively describe the processes of hygrothermal grain processing in vacuum conditions, assign processing parameters and manage them. Mathematical models of hygrothermal processes have been developed based on the method of similarity of the functioning of technical systems depending on the parameters of the medium and the structure of capillary-porous grain shells.
Keywords: hydrothermal effects, grain crops, vacuum, nanotechnology, humidification, drying, wet-heat treatment, capillary-porous materials, microcapillary, the criterion of sublbiya, the method of similarity of the functioning of technical systems