No. 6

Rationale for the choice of design parameters of cylindrical electric field sensors that increase the sensitivity of the sensor

In the work, a reasonable choice of design parameters of cylindrical electric field strength sensors is carried out, which makes it possible to significantly increase their sensitivity. The dependence of the sensor sensitivity on the radius R, length h and angular size θ₀ of its sensitive elements is established. An analysis of this dependence shows that it is not expedient to increase the sensitivity of the sensor by increasing its radius R and the angular size θ₀ of the sensitive elements, since their increase is limited by the finite values of the design dimensions. So, increasing the radius of the sensor to increase the sensitivity leads to an unacceptable increase in its size. An increase in the angular size θ₀ of the sensitive element is possible only up to the optimal angular sizes equal to 58 or 60°. With such values of θ₀, the sensors have errors, respectively, equal to σ = ± 0,2 % and σ = –1 % in the spatial measurement range 0 ≤ a ≤ 0,5. An analysis of the dependence of the sensor sensitivity on its design parameters made it possible to single out only one design parameter, due to which it is possible to increase the sensor sensitivity smoothly or step by step. This parameter is the length h of the sensitive element of the sensor. In this regard, in order to increase the sensitivity of the cylindrical electric field strength sensor, the idea of a telescopic change in the length h of the cylindrical base of the sensor and its sensitive elements was adopted, which was implemented in the new design of the sensor.

Thus, the conducted studies made it possible to create a single-coordinate electric induction sensor of the electric field strength of a cylindrical type with the possibility of a smooth or stepwise increase in its sensitivity.

Keywords: sensor, cylindrical sensor, intensity, electric field, sensitivity, measurements.

End of Service Life Indicator for Respirator Cartridges

The paper presents an overview of the development of systems for indicating the resource of protective properties of sorbents in cartridges of gas masks and respirators for the period from the first quarter of the twentieth century to the present. Two groups of indicators can be distinguished – passive, widely represented by colorimetric sensing elements, as well as active – mechanoelectronic, gas, capacitive, chemoresistor, optical, thermal. The analysis of the main advantages and disadvantages of indicators is presented, the prospects of their use as part of respiratory protection against toxic substances are indicated. Information about the main indicator development companies is provided.

Keywords: indicators, resource of protective properties, respirator, gas mask.

Software testing methods

This article provides an overview of existing software testing methods. The functionality of software testing automation tools, their positive and negative aspects are considered. The technology of secure computing architecture «Elbrus» is considered as one of the software testing methods using hardware support.

Keywords: software testing, verification, code analysis, static analysis, dynamic analysis, error detection, secure computing technology.

Conversion of video images into a matrix, evaluation and selection of high-quality algorithms

This article discusses methods of converting video images into a matrix by dividing the image into individual pixels and encoding the colors of each pixel into a numerical form. Each video frame is represented by a matrix, and the elements of the matrix represent the colors of a certain pixel. The methodology for converting an image into a matrix using the Python library is described in detail. The results of video image processing are presented in the form of histograms of the «cotton.jpg» images. An analysis of the capabilities of known image processing algorithms, including Linear Mapping, Optical Flow, Interpolation, Wavelet Transform, and others, was conducted. By comparing the known image processing algorithms, it was established that the Interpolation algorithm provides the most accurate and reliable results.

Keywords: matrix, frame, pixel, image processing, accuracy, reliability, interface.

Development of a hybrid scanning system for selective laser melting installations

The results of the development of a hybrid scanning laser system for selective laser melting (SLM) installations, which combine the advantages of two- and three-axis scanning systems, are presented. The scanning system is easy to operate and allows you to change the size of the focal spot in the working plane in the range from 80 to 250 microns on a scanning field of 320 × 320 mm. The key features of two- and three-axis scanning systems are briefly considered. An analysis was made of methods for changing the diameter of the focal spot, as a result of which a method for changing the divergence of the collimated beam was chosen. A brief method for calculating the F-theta of a lens that is part of a hybrid scanning system is described, which makes it possible to obtain optimal characteristics when the lens and the scanning system work together.

Keywords: two-axis and three-axis scanning system, collimator, variable divergence, F-theta objective, scanning head, focal spot size.

Detection and Quantification of Corrosion on Reinforced Concrete Surfaces Using Image Analysis

The article considers the possibility of determining a quantitative assessment of the corrosion of reinforced concrete structures using the processing of images obtained from technical means of visual control. The average saturation value of all pixels is calculated. Quantification is carried out by measuring the area of corrosion at various threshold values and determining the location of the centers of areas with a high degree of corrosion in the image.

Keywords: reinforced concrete structures, corrosion, visual inspection, panoramic imaging, corrosion quantification.

An indicator for evaluating the effectiveness of measures to ensure the security of personal data of the personnel body of the Defense industry

This article provides an indicator for evaluating the effectiveness of measures to ensure the security of personal data of a personnel body of an industrial complex organization (hereinafter referred to as the MIC). The types of characteristics of the violator's capabilities to implement threats to information security are given, the possibilities for processing personal data (hereinafter referred to as PD) in conditions of threats to their security and the implementation of measures aimed at preventing violations of information security conditions are considered. The basic term for the definition of «efficiency» is considered and, based on this, the function of implementing the PD processing processes of the personnel body of the defense industry is given.

Keywords: efficiency, efficiency evaluation indicator, personal data security, information security.

Strategy for selecting the optimum velocity when applying algorithms to avoid dynamic obstacles

The purpose of the work is to review existing collision avoidance algorithms in multi-agent environments (Velocity Obstacle, Reciprocal Velocity Obstacles and Hybrid Reciprocal Velocity Obstacles), study and propose a strategy for their application. To prove the operability of the proposed approach for each considered algorithm, an implementation was carried out in a software package for debugging and demonstration. Experimental scenarios were described, observations were made, results were compared for each of the algorithms, and conclusions were drawn.

Keywords: motion modelling, modelling algorithms of group control, multi-agent navigation.