articles
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№ 3(99)
31 may 2022 year
Rubric: Algorithmic efficiency Authors: Klyshnikov K., Barbarash L., Danilov V., Ganyukov V., Onishchenko P., Ovcharenko E. |
A significant increase in the number of transcatheter aortic valve replacements entails the development of auxiliary systems that solve the problem of intra- or preoperative assistance to such interventions. The main concept of such systems is the concept of computerized automatic anatomical recognition of the main landmarks that are key to the procedure. In the case of transcatheter prosthetics – elements of the aortic root and delivery system. This work is aimed at demonstrating the potential of using machine learning methods, the modern architecture of the ResNet V2 convolutional neural network, for the task of intraoperative real-time tracking of the main anatomical landmarks during transcatheter aortic valve replacement. The basis for training the chosen architecture of the neural network was the clinical graphical data of 5 patients who received transcatheter aortic valve replacement using commercial CoreValve systems (Medtronic Inc., USA). The intraoperative aortographs obtained during such an intervention with visualization of the main anatomical landmarks: elements of the fibrous ring of the aortic valve, sinotubular articulation and elements of the delivery system, became the output data for the work of the selected neural network. The total number of images was 2000, which were randomly distributed into two subsamples: 1400 images for training; 600 – for validation. It is shown that the used architecture of the neural network is capable of performing detection with an accuracy of 95-96% in terms of the metrics of the classification and localization components, however, to a large extent does not meet the performance requirements (processing speed): the processing time for one aortography frame was 0.097 sec. The results obtained determine the further direction of development of automatic anatomical recognition of the main landmarks in transcatheter aortic valve replacement from the standpoint of creating an assisting system – reducing the time of analysis of each frame due to the optimization methods described in the literature. Continue... |
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| The article deals with the problem of packing objects of arbitrary geometry. Modern methods of designing irregular packing schemes use a mathematical model based on phi-functions and a hodograph vector function of dense placement. These methods make it possible to obtain exact solutions, but they are time-consuming and very sensitive to the dimension of the problem being solved and the degree of detail of the geometry of vector objects. The use of a discrete representation of placed objects in the form of orthogonal polyhedra can signifi increase the speed of construction a packing, which makes the problem of adequately transforming the shape of placed objects (vector models in the two-dimensional case and polygonal models in the three- dimensional case) relevant. The aim of the study is to systematize methods that provide the formation of orthogonal polyhedra of various dimensions for describing objects and containers of arbitrary geometry. Methods for creating orthogonal polyhedra based on set-theoretic operations (addition, subtraction and intersection), analytical modeling using a set of functions and relational operators, as well as voxelization of fl and volumetric object models are considered. The use of set-theoretic operations is best suited for the manual creation of orthogonal polyhedra with relatively simple geometry. The method of analytical modeling is intended for the formation of voxelized objects based on geometric fi es described by a set of analytically specifi functions. The application of various relational operators to obtain orthogonal polyhedra that describe the contour, internal and external regions of analytical given objects is shown. An algorithm for creating a container in the form of an orthogonal polyhedron based on a given vector model is proposed, which makes it possible to solve problems of irregular packing of objects inside containers of arbitrary shape. All the methods presented in the article are programmatically implemented with a generalization in terms of dimension and are applicable to solving any types of cutting and packing problems. Continue... | |
| This paper considers the actual problem of graphical information converting back into raw data format that was used to represent it. This is due to the great scientifi achievements contained in editions from the Soviet period, as well as the intention global publishers from "unfriendly" countries to close access for Russian and Belarusian organisations to scientific publications and technical information databases. As a result, Russian scientists can only have graphical materials in formats similar to PDF documents. This paper considers a fairly simple way of solving this problem when digitising graphs in printed or electronic publications with low resolution and a large picture scale, which does not allow to detail its separate fragments. The procedure for pre-processing the original image in bitmap format is described. In order to improve the numerical data resulting accuracy from the subsequent digitising, a number of features are recommended, which are available in the well-known and most common graphical editors. These functions include changing the color mode of the image, color inversion, sharpening and contrast, linear scaling (vertical and horizontal scaling), and graph line spline approximation. The above operations are accessible to users with the minimum familiarity of graphical editors Microsoft Power Point and Adobe Photoshop. As an developed procedure use example, the results of FRB 160317 signal digitising (a so-called Fast Radio Burst), are presented. The digitising of its graphical image has provided more accurate additional information on signal characteristics not given by publication authors. A visual evaluation of the digitised FRB 160317 signal accuracy by matching it with the original graphical image is presented, which showed a satisfactory match to the original. The numerical data array obtained by digitising the raw graphical material using a pre-processing procedure is becomes available for further analysis. The described way can be used by university teachers both at the initial stages of students teaching to work with images and carry out data analysis, and when preparing teaching materials when organising the educational process using distance learning technologies. The results are applicable at the starting stages of scientifi research in the initial data set formation for dependency analysis in various subject areas, where there are no initial samples refl the results of observation. Continue... | |
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№ 3(99)
31 may 2022 year
Rubric: Data protection Authors: Malinichev D., Andreev A., Kuchmezov K., Mochalov V., Pokazanieva S., Ratanova O. |
The problem of building an information infrastructure resistant to computer attacks is relevant for organizing the work of any enterprise. Therefore, the ability to assess the existing or developing information infrastructure is very important. In this regard, the article deals with the problem of categorizing objects of critical information infrastructure in the context of the need to assess their relationship. The current legislative acts, which are the information base for determining the objects of critical information infrastructure and determining their purpose, structure and composition, are considered, as well as the criteria for the significance of objects are determined. The article also defines the links between critical information infrastructure objects, their resistance to computer attacks, as well as possible damage due to disruption of their functioning or the performance of a critical process. The article provides a description of the criteria that are subject to assessment and a methodology for assessing the stability of critical information infrastructure objects to computer attacks and assessing possible damage due to disruption of the functioning or performance of critical processes by objects of critical information infrastructure. An augmented solution is proposed for assessing the stability of the functioning of critical information infrastructure objects with various options for their connection. The possibility of assessing the cumulative damage due to disruption of the functioning of interconnected objects of critical information infrastructure is considered. Continue... |
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№ 3(99)
31 may 2022 year
Rubric: Researching of processes and systems Authors: Blinov A., Borisov A., Filippenkov K., Konchina L., Maslova K. |
The objective of the study is the development of 3D variable-length link model with electric drives to be used in designing of next-generation comfortable exoskeletons. The developed link model has two inertial absolutely rigid sections on its ends and a variable- length section, considered weightless, in between. The mechanical part of the variable-length link model has been implemented in the universal computer math "Wolfram Mathematcia 11.3" environment by building the system of Lagrange – Maxwell differential equations. The electro-mechanical link model with electric drives has been implemented in the MatLab Simulink environment. The implemented model includes the following units: the trajectory synthesis unit per each degree of freedom, the unit for controlling torques calculation based on differential equations of motion, the unit for selecting electric motors with gears, the unit for calculating electric current per each motor and implementing the control system. The electric motors, reducers, rack and pinion gears implementing the specified and programmed link motion have been selected. The inertial and geometrical variable-length link parameters corresponding to the human tibia in the period of the single-support step phase have been selected. The drives implementing the link rotation are situated in the bottom link point in the combination of two orthogonal cylindrical hinges. One of these hinges is fixed to the supporting surface, the other one is fixed to the link end. This hinge combination simulates human ankle joint in the single-support step phase. The drive controlling the link length change is situated at the end of the bottom absolutely rigid weighty link section. The programmed trajectories for generalized coordinates are specified based on the simulation requirements of the anthropomorphic tibia motion. As a result, the electro-mechanical model of a variable- length link with parameters corresponding to the average man’s tibia has been developed. The drives and gears that allow implementing the motion close to anthropomorphic one have been selected. The implementation of this motion based on the developed software in the computer math "Wolfram Mathematica 11.3" environment and in the MatLab Simulink system has been demonstrated. The numerical calculations are presented. Continue... |
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№ 4(100)
31 august 2022 year
Rubric: Performance management Authors: Kychkin A., Gorshkov O. V., Kukarkin M. |
The research focuses on the development of applied software systems for automated environmental monitoring. The task of developing and integrating applied software, in particular calculation and analytical models based on machine learning (ML) methods, with an IoT platform of digital eco-monitoring for industrial enterprises is considered. Such a platform is used to create software and hardware systems of CEMS – Continuous Emissions Monitoring System class, designed for continuous monitoring of pollutant emissions into the atmospheric air at production facilities. Use of ML tools integrated with the platform allows to expand significantly the functionality of the existing CEMS, in particular to quickly build new SaaS services for forecasting the dynamics of pollution distribution. Given the high requirements for industrial systems, there is a need to create a specialized software product – an analytical server that implements the management of connected predictive analytical ML models with the required level of service quality, including automatic initialization of new analytical scripts as classes, isolation of individual components, automatic recovery after failures, data security and safety. The paper proposes a scheme of functional and algorithmic interaction between the IoT platform of digital eco- monitoring and the analytical server. The proposed implementation of the analytical server has a hierarchical structure, at the top of which is an application capable of accepting high-level REST requests to initialize calculations in real time. This approach minimizes the impact of one analytical script (class) on another, as well as extending the functionality of the platform in "hot" mode, that is, without stopping or reloading. Results demonstrating automatic initialization and connection of basic ML models for predicting pollutant concentrations are presented. Continue... |
