In the paper, parametric equations of right conoidal surfaces with an orthogonal coordinate system with different guiding curves are obtained for the first time. Parametric equations for conoids with guide curves sine, cosine and parabola are presented. In the MathCad system, the constructions of right conoids with selected guide curves with various initial geometric parameters are visually performed and presented in the paper for the possibility of expanding their use in architectural design, construction and other industries.
Keywords: conoid, orthogonal coordinate system, sine, cosine, parabola, parametric equation, MathCad system
The article discusses identification methods in industry and equipment presented on the Russian market for marking and identification of objects. The purpose of the article is to analyze the equipment and installations available on the Russian market for marking and identification of straight-seam steel pipes in production. A comparison of methods based on a scoring system for marking and identification of straight-seam steel pipes in production is presented. Barcode marking technologies using labels, laser marking and RFID tags are presented and considered as identification methods.
Keywords: barcoding, laser marking, RFID tag, straight-seam steel pipe, thermal label printer, automated identification system
An approach to solving the problem of justifying a project for the development of a complex system, taking into account the possibility of realizing the values of its characteristics and the presence of restrictions on their values is proposed . The general goal is formulated in terms of the theory of fuzzy sets and the theory of possibilities. Based on the global development goal of a complex system, local goals and objectives are determined. The problem of taking into account factors influencing the achievement of a global goal is considered. Achieving the general goal is associated with taking into account restrictions on the values of system indicators, as well as the need to determine their optimal values. Unlike existing models, the proposed approach allows us to consider a more general relationship between the elements of the system and take into account the fuzzy nature of the implementation of the parameters. To solve this problem, an effective decomposition method has been developed.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
The integration of blockchain technology with the Internet of Things (IoT) offers transformative potential for various sectors. This article delves into 16 distinct methods of integrating blockchain with IoT, emphasizing that there isn't a one-size-fits-all solution. Each method has its unique advantages and potential drawbacks, necessitating careful consideration based on specific IoT system requirements. For instance, integrating with public blockchains like Bitcoin and Ethereum offers transparency and decentralization but faces scalability issues. Sidechains introduce flexibility but might pose security risks. Blockchain platforms like Hyperledger Fabric expedite development but can lead to vendor lock-in. The diversity of these methods underscores the importance of a well-thought-out approach tailored to the specific needs of the IoT system in question. As technology evolves, we anticipate more innovative approaches to emerge, emphasizing the continuous need for research, experimentation, and collaboration to fully harness the potential of IoT and blockchain integration.
Keywords: blockchain , IOT , BIoT, smart contracts, IoT security
Assessment of the technical condition (hereinafter TC) of technical systems is a prerequisite for a modern strategy for their operation. The study of new methods and algorithms that provide express assessments of the condition of technical devices and reduce the subjective component in these assessments is an urgent and in demand task. The paper presents a constructive approach to assessing the TC indicators of complex technical systems based on a modified method of analyzing hierarchies and the TC index (hereinafter referred to as ITS) of equipment, which is determined on the basis of weights and ITS of the main components of the equipment in question. The ITS of the main nodes is calculated based on the comparative characteristics of the operating parameters of the equipment during its operation, and the weights of the nodes are determined based on the methods of the matrix of paired comparisons (Saaty method) and the degree of importance of the line (DIL - Degree Importance Line method). The testing of the methodology and algorithms in this study was carried out on the basis of statistical data from a NASA turbojet engine (hereinafter referred to as turbofan engine), published in 2008.
Keywords: technical condition, technical condition index, complex technical system, maintenance and repair, hierarchy analysis method, DIL method, constructive method for assessing technical condition, algorithm for express assessment of technical condition
The article contains the methodology and results of theoretical and experimental studies of the stress-strain state of a conical radial-beam dome with triangular shell elements. The results obtained by various methods are analyzed and compared. The triangular membrane panel is part of the radial beam dome structure and consists of a support frame and a steel membrane in the shape of a triangle. The shape of the triangle forming the membrane panel can be different and depends on the number of ribs in the radial beam dome. The supporting contour is a compressed-bending element of the dome and is made, as a rule, from a rolled steel profile with a channel section. The membrane is made of thin steel sheet and attached to the upper flange of the channel with self-tapping screws or spot welding. To assess the strength and deformability of a steel membrane sheet, its operation under the action of a uniformly distributed snow load, an unevenly distributed snow load and a concentrated installation load was considered. Several options for nonlinear static calculations in various computer systems are shown.
Keywords: building structures, wooden structures, membrane panel, stress-strain state, radial beam dome, dome, membrane, design, experimental study
The article explores the problem of creating aircraft flight models in the Simulink environment. The reference systems in which transformations are carried out are considered. The equations of motion used in the simplest converters are given. The initial conditions for the equations are determined: the speed of the body, the angular orientation of the body's pitch position, the angle between the velocity vector and the body, the speed of rotation of the body, the initial position, the mass and inertia of the body, the source of gravity, the acceleration due to gravity, the curb and total mass of the body, speed of air flow, inertia of an empty and full body, flight trajectory, etc. An analysis of converters of aerodynamic forces and moments into the trajectory of motion as part of an aerospace package in the Simulink environment was carried out. Recommendations are given for their use for various modeling purposes. The results of modeling a simple converter with three degrees of freedom are presented.
Keywords: modeling, MatLab, Simulink, equations of motion, aerodynamic torque, flight path, coordinate transformations, reference system, degrees of freedom
The article discusses the issues of identifying and ranking threats at an important government facility. The classification of threats by type is described. The article discusses the concepts of “design-based threats” and “the most dangerous variant of the violator’s actions” and their differences. An example of ranking threats and reducing their number to reduce the dimensionality of the vulnerability analysis problem is considered. An important government object is considered as an object in the example. Experts are tasked with ranking threats according to the level of potential losses for an important government facility if they are realized. In practice, the implementation of an accepted design threat may lead to lower potential losses than the most dangerous option for violators and, as a result, to lower requirements for the effectiveness of the physical protection system.
Keywords: comprehensive security, methods, models, security forces, intruders, important government facilities, clashes between security forces and attacks, ranking of threats
A method for recording holograms using digital cameras with high spatial resolution is considered. To register holograms obtained in optical setups with an inclined reference beam, a high resolution of registration systems is required. To do this, it is necessary to use media with a resolution of 2000-4000 lines per mm. The use of photographic plates requires a fairly long exposure and development time, which is usually done separately from the optical setup. In the case of holographic interferometry systems, it is necessary to provide for mounting the hologram back into the optical setup with sufficiently high accuracy. Therefore, digital holography methods have been developed to record holograms on photomatrices with limited resolution. These methods are based on the use of optical schemes at small angles (less than 5 degrees) between interfering beams. Recently, sensors with a single element size of 1.33 µm and 0.56 µm have appeared. This resolution makes it possible to return to registration schemes with angles between interfering beams of 30-60 degrees. This allows us to hope for the revival of holographic methods and methods of holographic interferometry at the modern level without the use of intermediate recording media.
Keywords: digital holography, high spatial resolution photo matrix, tilted reference beam holography, Fourier transform
The article proposes a general formalized model of the task of processing and extracting potential key skills from job descriptions to determine the relevance of training areas and possible areas of employment for graduates. The formalized model is used in the software implementation of the job clustering module based on the obtained sets of key skills within the framework of a comprehensive toolkit for remote career guidance.
Keywords: vacancies, demand for training areas, career guidance, digitalization of career guidance, formalized model, clustering, professions, key skills
A Simulink model of a lightweight aircraft is being studied as part of the Aerospace Blockset package, including a system model of the aircraft, an environmental model, a model of pilot influences, and a visualization block. The structure of the flight model is considered and models of the effects of the environment and wind are disclosed in detail, consisting of blocks of physical terrain features, wind models and an atmospheric model, a gravity model, each of which is set to an altitude. The Wind Shear Model block calculates the amount of wind shear as a function of altitude and measured speed wind. The Discrete Wind Gust Model block determines the resulting wind speed as a function of the distance traveled, the amplitude and length of the gust. The turbulence equations comply with the MIL-F-8785C specification, which describes turbulence as a random process determined by velocity spectra. Simulation results are presented that reflect changes in the trajectory of movement under various wind influences specified in the wind speed gradient block.
Keywords: modeling, airplane flight, Simulink, Aerospace Blockset, crosswind, turbulence, turbulence equations, gravity model, motion trajectory
In accordance with the requirements of Federal Law No. 384-FZ, the safety and reliability of buildings and structures must be ensured. One of the ways to confirm the safety and reliability of building structures is to conduct field tests. The authors of this article have developed a method for full-scale testing of a reinforced concrete beam with a span of 14.52 m as part of a monolithic reinforced concrete ribbed floor. The procedure for testing the beam was drawn up with the development of measures to ensure safety during work, the adjustment of the beam testing method by loading was performed, the beam was tested by loading method with fixation of its deflections, followed by analysis of the test results. The test results showed that the developed method can be used as a full-scale test to confirm the safety and reliability of building structures, namely horizontal reinforced concrete structures.
Keywords: building structures, beam, destruction, safety, methodology, technical condition, field tests
The relevance of the issue of variant design is considered, taking into account the analysis of previously applied solutions. The concept of installation manufacturability of objects is revealed, its component properties are substantiated. A table of the hierarchy of installation manufacturability properties has been generated. The functions of each level of the property hierarchy are disclosed. The weight indicators of the criteria were calculated using an expert survey. a formula for a complex indicator of installation manufacturability was obtained. A hypothesis has been put forward about the quantitative assessment of the levels of installation manufacturability.
Keywords: manufacturability, installation manufacturability, levels of hierarchy of installation manufacturability, weight of indicators of properties of installation manufacturability, installation of steel structures
motion of the body are obtained, which can only be solved numerically. The equilibrium equations are solved and the basic stationary modes of body motion are obtained. The main result is the most gentle body planning mode. In the matlab computer mathematics system, a set of programs is written that searches for a numerical solution and outputs trajectories. The movement of the modes under consideration is modeled and the stability of the main modes is looked at using numerical calculations.
Keywords: body, planning mode, stability, geometric dimensions
The wear resistance of friction units with a polymer coating and a special groove in their supporting structure is increased by minimizing the heating of the contact zone of the rubbing surfaces through effective heat removal due to the presence of a transverse recess (groove). In addition, this design helps to minimize the dry friction process, since it directly affects the distribution of the lubricating fluid. Increased loads of friction units entail characteristic changes in the properties of lubricants. In our opinion, taking into account the viscosity indicators, depending on temperature and pressure, will allow us to more accurately characterize the operation of the structure in various friction modes. The effect of a modified friction unit design (with a polymer coating and a groove) on improving performance in general is described. In addition, comparing the standard and modified designs, it can be noted that the load capacity has significantly increased and the friction coefficient has decreased. At the same time, the service life and the overhaul period of the friction unit have increased, which is a significant effect for the mechanical engineering industry.
Keywords: friction unit, index, friction coefficient, polymer coating, load, tribocoupling