scholarly journals Establishment of the dependence of the strength indicator of the composite material of pressure hoses on the character of single damages

2021 ◽  
Vol 6 (1 (114)) ◽  
pp. 21-27
Author(s):  
Sergii Nazarenko ◽  
Galina Kushnareva ◽  
Natalia Maslich ◽  
Ludmila Knaub ◽  
Nataliia Naumenko ◽  
...  

Experimental studies are presented and the dependence of the change in the strength of the material of a pressure head fire hose of type T with an inner diameter of 77 mm in the longitudinal direction is established, taking into account single damages. The work describes the plan of the experiment and carried out a number of field experiments to determine the effect of the length ld and the depth K damage on the strength F of the hose material, that is, obtaining the dependence F=f (ld, K). A mathematical method of experiment planning was used and a plan was drawn up for a complete multivariate experiment of type 2k with an acceptable model accuracy of 5 %. The limits of variation of the factors are set taking into account a priori information, experimental capabilities and on the basis of the results of preliminary search experiments. The dependence in the coded and natural values of the factors is obtained. The reliability of the relationship was checked using the Fisher test, the calculated value of which was 5.98, which confirms the adequacy of the described process with a probability of 95 %. Analyzing experimental studies of the dependence of the change in the strength of the hose material on the length and depth of damage, it can be said that the change in the strength of the hose almost linearly depends on the specified damage parameters. It is found that with increasing damage, the strength of the hose material significantly decreases. When varying the length factor and the greatest depth of damage, K=0.4 mm, the strength of the hose material decreases from 11.67 kN to 8.77 kN, and in percentage terms by 25 %. The results obtained can be used in practical units of emergency rescue teams, when diagnosing hidden damage in pressure head fire hoses in order to prevent their failure in case of fires

1997 ◽  
Vol 119 (3) ◽  
pp. 447-454 ◽  
Author(s):  
A. V. Ephanov ◽  
Y. Hurmuzlu

This paper presents an approach to the implementation of sensory feedback in a robotic telemanipulation system. The system considered here consists of kinematically similar master-slave robotic manipulators. We propose a control scheme whereby the slave tracks the motion commanded by the human operator through the master mechanism. The scheme also accommodates, in a unified manner, different sources of sensory feedback. These include combined effects of the interaction with unknown environments and changes in structural properties of the slave manipulator due to additional unknown loads. The control algorithm is based on continuously sliding variable structure control, which is a nonlinear and highly robust control scheme. Due to the robustness of the scheme, the need for a priori information about the environment and the load is minimal. This information can be passed on to the system in the form of upper bounds of the interaction forces and additional loads. Experimental studies with a Pneumatic Haptic Interface (PHI) system were conducted to evaluate the performance of the proposed scheme. We used a virtual slave with percent 25 uncertainty to verify the robustness of the controller. We have shown that the proposed scheme can accurately estimate the environmental interaction torques and can robustly track the trajectories commanded by the human operator.


2018 ◽  
Vol 226 ◽  
pp. 04045 ◽  
Author(s):  
Dmitriy A. Bezuglov ◽  
Viacheslav V. Voronin ◽  
Vladimir A. Krutov

Analytical equations of a new spline approximation method for filtering impulse noise in images are obtained. The proposed method differs from the known ones: when filtering images, one-dimensional sequential spline functions are used for direct and inverse transformations, and the processing is performed in rows and columns. In this work, experimental studies based on computer simulation using special test images on the background of impulse noise were conducted. Experimental studies have shown the operability and high efficiency of the developed method, which allow to improve the quality of image filtering by up to 10 dB. In this case, the properties of spline functions make it possible to abandon the use of various masks, that is, to abandon inefficient linear methods of image filtering. The method can be used to create digital image processing systems in the industry, to create autonomous robots, under observation conditions that complicate the registration process, and in the absence of a priori information about the form of background noise.


Author(s):  
Maria A. Milkova

Nowadays the process of information accumulation is so rapid that the concept of the usual iterative search requires revision. Being in the world of oversaturated information in order to comprehensively cover and analyze the problem under study, it is necessary to make high demands on the search methods. An innovative approach to search should flexibly take into account the large amount of already accumulated knowledge and a priori requirements for results. The results, in turn, should immediately provide a roadmap of the direction being studied with the possibility of as much detail as possible. The approach to search based on topic modeling, the so-called topic search, allows you to take into account all these requirements and thereby streamline the nature of working with information, increase the efficiency of knowledge production, avoid cognitive biases in the perception of information, which is important both on micro and macro level. In order to demonstrate an example of applying topic search, the article considers the task of analyzing an import substitution program based on patent data. The program includes plans for 22 industries and contains more than 1,500 products and technologies for the proposed import substitution. The use of patent search based on topic modeling allows to search immediately by the blocks of a priori information – terms of industrial plans for import substitution and at the output get a selection of relevant documents for each of the industries. This approach allows not only to provide a comprehensive picture of the effectiveness of the program as a whole, but also to visually obtain more detailed information about which groups of products and technologies have been patented.


2021 ◽  
Vol 13 (15) ◽  
pp. 8324
Author(s):  
Viacheslav Morozov ◽  
Sergei Iarkov

Present experience shows that it is impossible to solve the problem of traffic congestion without intelligent transport systems. Traffic management in many cities uses the data of detectors installed at controlled intersections. Further, to assess the traffic situation, the data on the traffic flow rate and its concentration are compared. Latest scientific studies propose a transition from spatial to temporal concentration. Therefore, the purpose of this work is to establish the regularities of the influence of traffic flow concentration in time on traffic flow rate at controlled city intersections. The methodological basis of this study was a systemic approach. Theoretical and experimental studies were based on the existing provisions of system analysis, traffic flow theory, experiment planning, impulses, probabilities, and mathematical statistics. Experimental data were obtained and processed using modern equipment and software: Traficam video detectors, SPECTR traffic light controller, Traficam Data Tool, SPECTR 2.0, AutoCad 2017, and STATISTICA 10. In the course of this study, the authors analyzed the dynamics of changes in the level of motorization, the structure of the motor vehicle fleet, and the dynamics of changes in the number of controlled intersections. As a result of theoretical studies, a hypothesis was put forward that the investigated process is described by a two-factor quadratic multiplicative model. Experimental studies determined the parameters of the developed model depending on the directions of traffic flow, and confirmed its adequacy according to Fisher’s criterion with a probability of at least 0.9. The results obtained can be used to control traffic flows at controlled city intersections.


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 177
Author(s):  
Iliya Gritsenko ◽  
Michael Kovalev ◽  
George Krasin ◽  
Matvey Konoplyov ◽  
Nikita Stsepuro

Recently the transport-of-intensity equation as a phase imaging method turned out as an effective microscopy method that does not require the use of high-resolution optical systems and a priori information about the object. In this paper we propose a mathematical model that adapts the transport-of-intensity equation for the purpose of wavefront sensing of the given light wave. The analysis of the influence of the longitudinal displacement z and the step between intensity distributions measurements on the error in determining the wavefront radius of curvature of a spherical wave is carried out. The proposed method is compared with the traditional Shack–Hartmann method and the method based on computer-generated Fourier holograms. Numerical simulation showed that the proposed method allows measurement of the wavefront radius of curvature with radius of 40 mm and with accuracy of ~200 μm.


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