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The creation of a virtual laboratory stand that allows one to obtain reliable characteristics that can be proven as actual, taking into account errors and noises (which is the main distinguishing feature of a computational experiment from model studies) is one of the main problems of this work. It considers the following task: there is a rectangular waveguide in the single operating mode, on the wide wall of which a technological hole is cut, through which a sample for research is placed into the cavity of the transmission line. The recovery algorithm is as follows: the laboratory measures the network parameters (S₁₁ and/or S₂₁) in the transmission line with the sample. In the computer model of the laboratory stand, the sample geometry is reconstructed and an iterative process of optimization (or sweeping) of the electrophysical parameters is started, the mask of this process is the experimental data, and the stop criterion is the interpretive estimate of proximity (or residual). It is important to note that the developed computer model, along with its apparent simplicity, is initially ill-conditioned. To set up a computational experiment, the Comsol modeling environment is used. The results of the computational experiment with a good degree of accuracy coincided with the results of laboratory studies. Thus, experimental verification was carried out for several significant components, both the computer model in particular and the algorithm for restoring the target parameters in general. It is important to note that the computer model developed and described in this work may be effectively used for a computational experiment to restore the full dielectric parameters of a complex geometry target. Weak bianisotropy effects can also be detected, including chirality, gyrotropy, and material nonreciprocity. The resulting model is, by definition, incomplete, but its completeness is the highest of the considered options, while at the same time, the resulting model is well conditioned. Particular attention in this work is paid to the modeling of a coaxial-waveguide transition, it is shown that the use of a discrete-element approach is preferable to the direct modeling of the geometry of a microwave device.

Protection of aquatic biological resources in the coastal area has significant features (a large number of small fishing vessels, the dynamism of the situation, the use of coastal protection), by virtue of which stands in a class of applications. A mathematical model of protection designed for the determination of detection equipment and means of violators of the situation in order to ensure the function of deterrence of illegal activities. Resolves a tactical game-theoretic problem - find the optimal line patrol (parking) means of implementation (guard boats) and optimal removal of seats from the shore fishing violators. Using the methods of the theory of experimental design, linear regression models to assess the contribution of the main factors affecting the results of the simulation.

In order to enhance the sustainability and adequacy of the model is proposed to use the mechanism of rankings means of protection, based on the borders and the rank and Pareto allows to take into account the principles of protection and further means of protection. To account for the variability of the situation offered several scenarios in which it is advisable to perform calculations.

The paper deals with a prey-predator model, which describes the spatiotemporal dynamics of plankton community and the nutrients. The system is described by reaction-diffusion-advection equations in a onedimensional vertical column of water in the surface layer. Advective term of the predator equation represents the vertical movements of zooplankton with velocity, which is assumed to be proportional to the gradient of phytoplankton density. This study aimed to determine the conditions under which these movements (taxis) lead to the spatially heterogeneous structures generated by the system. Assuming diffusion coefficients of all model components to be equal the instability of the system in the vicinity of stationary homogeneous state with respect to small inhomogeneous perturbations is analyzed.

Necessary conditions for the flow-induced instability were obtained through linear stability analysis. Depending on the local kinetics parameters, increasing the taxis rate leads to Turing or wave instability. This fact is in good agreement with conditions for the emergence of spatial and spatiotemporal patterns in a minimal phytoplankton–zooplankton model after flow-induced instabilities derived by other authors. This mechanism of generating patchiness is more general than the Turing mechanism, which depends on strong conditions on the diffusion coefficients.

While the taxis exceeding a certain critical value, the wave number corresponding to the fastest growing mode remains unchanged. This value determines the type of spatial structure. In support of obtained results, the paper presents the spatiotemporal dynamics of the model components demonstrating Turing-type pattern and standing wave pattern.

Industrial imaging or “machine vision” is currently a key technology in many industries as it can be used to optimize various processes. The purpose of this work is to create a software and hardware complex for measuring the overall and weight characteristics of cargo based on an intelligent system using neural network identification methods that allow one to overcome the technological limitations of similar complexes implemented on ultrasonic and infrared measuring sensors. The complex to be developed will measure cargo without restrictions on the volume and weight characteristics of cargo to be tariffed and sorted within the framework of the warehouse complexes. The system will include an intelligent computer program that determines the volume and weight characteristics of cargo using the machine vision technology and an experimental sample of the stand for measuring the volume and weight of cargo.

We analyzed the solutions to similar problems. We noted that the disadvantages of the studied methods are very high requirements for the location of the camera, as well as the need for manual operations when calculating the dimensions, which cannot be automated without significant modifications. In the course of the work, we investigated various methods of object recognition in images to carry out subject filtering by the presence of cargo and measure its overall dimensions. We obtained satisfactory results when using cameras that combine both an optical method of image capture and infrared sensors. As a result of the work, we developed a computer program allowing one to capture a continuous stream from Intel RealSense video cameras with subsequent extraction of a three-dimensional object from the designated area and to calculate the overall dimensions of the object. At this stage, we analyzed computer vision techniques; developed an algorithm to implement the task of automatic measurement of goods using special cameras and the software allowing one to obtain the overall dimensions of objects in automatic mode.

Upon completion of the work, this development can be used as a ready-made solution for transport companies, logistics centers, warehouses of large industrial and commercial enterprises.

The paper presents results of numerical modeling of stress-strain state of jack-up rigs used for shelf hydrocarbon reservoirs exploitation. The work studied the equilibrium stress state of a jack-up rig standing on seafloor and mechanical behavior of the rig under seismic loading. Surface elastic wave caused by a distant earthquake acts a reason for the loading. Stability of jack-up rig is the main topic of the research, as stability can be lost due to redistribution of stresses and strains in the elements of the rig due to seismic loading. Modeling results revealed that seismic loading can indeed lead to intermittent growth of stresses in particular elements of the rig’s support legs resulting into stability loss. These results were obtained using the finite element-based numerical scheme. The paper contains the proof of modeling results convergence obtained from analysis of one problem — the problem of stresses and strains distributions for the contact problem of a rigid cylinder indenting on elastic half space. The comparison between numerical and analytical solutions proved the used numerical scheme to be correct, as obtained results converged. The paper presents an analysis of the different factors influencing the mechanical behavior of the studied system. These factors include the degree of seismic loading, mechanical properties of seafloor sediments, and depth of support legs penetration. The results obtained from numerical modeling made it possible to formulate preliminary conclusions regarding the need to take site-specific conditions into account whenever planning the use of jack-up rigs, especially, in the regions with seismic activity. The approach presented in the paper can be used to evaluate risks related to offshore hydrocarbon reservoirs exploitation and development, while the reported numerical scheme can be used to solve some contact problems of theory of elasticity with the need to analyze dynamic processes.