The article discusses methods for automated determination of threshold values of parameters when assessing the critical state of technical systems. It explores the theoretical foundations and practical aspects of setting thresholds, including statistical, expert, and combined approaches. Particular attention is paid to mathematical models and algorithms for processing monitoring data. Various methods for determining threshold values are presented: computational, experimental, statistical, and expert. The features of applying adaptive thresholds, dynamic control, and machine learning systems are described. An analysis of existing approaches to determining critical conditions of equipment is conducted. Recommendations are developed for selecting optimal methods for determining thresholds, taking into account the specifics of technical systems. Comprehensive solutions are proposed that combine analytical and machine methods to improve the reliability and safety of computing complexes.

Keywords: automated control, threshold values, technical diagnostics, critical state, computing systems, machine learning, statistical analysis, expert systems, equipment monitoring, technical safety

Abstract: The scope of applying fiber-reinforced concrete in critical load-bearing structures, such as aerodrome pavements, is often limited by insufficient information regarding material behavior and life-cycle economics. This study addresses this gap by developing and evaluating an optimal hybrid mix of micro and macro-basalt fibers consisting of 1.5% and 0.5% of cement mass, respectively for high-performance airfield concrete, followed by a 30-year Life-Cycle Cost Analysis (LCCA). Mechanical testing confirmed the technical feasibility, showing significant performance gains over baseline concrete: 14.5% increase in compressive strength 72.8MPa and 18.2% increase in flexural strength 10.4MPa. These gains are attributed to enhanced durability, multi-scale crack control, and superior post-crack load-carrying capacity. The LCCA, conducted using a 6% discount rate, revealed that the hybrid option, which incurs a 13.03% higher upfront material cost, is economically viable only under the optimistic scenario where the improved durability eliminates the need for major rehabilitation over 30 years. This scenario yields a marginal LCC saving of 4% compared to the baseline. In conservative and moderate scenarios, the upfront cost outweighed the delayed or reduced rehabilitation costs. Overall, Hybrid Basalt Fiber Reinforced Concrete is a promising high-performance material that achieves cost parity if its durability benefits are maximized to prevent major rehabilitation. Future work should involve field trials and expanded LCCA incorporating operational downtime and risk-based performance modeling.

Keywords: aerodrome pavement, basalt fiber, hybrid fiber-reinforced concrete, life-cycle cost analysis, rehabilitation, discount rate, microfiber, macrofiber, net present value

The relevance of this article stems from the need to develop lightweight and scalable solutions for decentralized systems (blockchain, IoT), where traditional cryptographic methods are inefficient or excessive. A theoretical-practical method for protecting unmanned transportation systems against Sybil attacks has been developed, based on a server robot’s analysis of each client robot’s unique directional electromagnetic signal power map signature. Experimental solutions for Sybil attack protection are demonstrated using two aerial servers deployed on quadcopters. The proposed keyless Sybil attack defense method utilizes WiFi signal parameter analysis (e.g., power scattering and variable antenna radiation patterns) to detect spoofed client robots. Experiments confirm that monitoring unique radio channel characteristics effectively limits signature forgery. This physical-layer approach is also applicable to detecting packet injection in robot Wi-Fi networks. The key advantages of the developed method include the elimination of cryptography, reducing computational overhead; the use of physical signal parameters as a "fingerprint" for legitimate devices; and the method's scalability to counter other threats, such as traffic injection.

Keywords: protection against Sybil attacks, unmanned vehicle systems, electromagnetic signal power map, WiFi signal, signature falsification, spoofing, and synthetic aperture radar

Problem statement. When modeling a complex technical system, the issues of parameter estimation are of primary importance. To solve this problem, it is necessary to obtain a methodology that allows eliminating errors and inaccuracies in obtaining numerical parameters. Goal. The article is devoted to a systematic analysis of the methodology for estimating the parameters of a complex technical system using the interval estimation method. The research method. A systematic analysis of the methods of using interval estimates of numerical parameters is carried out. The decomposition and structuring of the methods were carried out. Results. The expediency of using a methodology for describing the parameters of a complex technical system using the interval estimation method is shown. An analysis of the use of various interval estimation models is presented. Practical significance. Application in the analysis and construction of complex systems is considered as a practical application option. The method of estimating the parameters of a complex technical system using the interval estimation method can be used as a practical guide.

Keywords: interval estimation, parameter estimation, numerical data, fuzzy data, complex technical systems

This paper proposes a mathematical model of the laminar flow of a truly viscous lubricant in the clearance of a radial plain bearing with a nonstandard support profile. The influence of a fluoroplastic-containing polymer coating and a groove on the shaft surface is considered, taking into account nonlinear effects, which improves the accuracy of the description of hydrodynamic processes. Thin-film approximations and continuity equations are used to determine the hydrodynamic pressure, load capacity, and friction coefficient. A comparison with existing calculation models demonstrated improved performance prediction. The results demonstrate the feasibility of ensuring stable shaft floatation, confirming the applicability of the developed model for engineering calculations of bearings with a polymer coating and a groove.

Keywords: radial plain bearing, mathematical modeling, true viscous lubricant, polymer composite coating, hydrodynamic regime, tribotechnical characteristics

This article presents a practical approach to the design of precast concrete frame buildings based on a developed methodology for accounting for the flexibility of joints between floor and roof elements, using a plate-and-rod model of a floor fragment. For two types of braced frames (with symmetrical and asymmetrical stiffener arrangements), an analysis of quantitative indicators of deformability and relative forces is presented, with reduction factors applied to the integral rigidity of the precast floor in its plane, obtained using the proposed methodology. This analysis compares this approach to the classical approach to designing precast frames, taking into account the rigidity of monolithic floors. The results of the calculation of frames using the proposed method show that with a decrease in the rigidity of the floors (reducing to equivalent rigidity, taking into account the flexibility of the seams in the joints of the floors), the vertical forces in the columns from horizontal loads decrease, and the moments in the stiffening diaphragms increase, that is, in the frame structures, both reserves and deficiencies in the bearing capacity can be identified, which is especially important during the inspection and subsequent reconstruction of buildings with the structural system under consideration.

Keywords: multi-story frame structural system, precast floor, flexibility, horizontal load, joint, rod model, equivalent stiffness coefficient

The article focuses on the development of a web portal for monitoring and forecasting atmospheric air quality in the Khabarovsk Territory. The study analyzes existing solutions in the field of environmental monitoring, identifying their key shortcomings, such as the lack of real-time data, limited functionality, and outdated interfaces. The authors propose a modern solution based on the Python/Django and PostgreSQL technology stack, which enables the collection, processing, and visualization of air quality sensor data. Special attention is given to the implementation of harmful gas concentration forecasting using a recurrent neural network, as well as the creation of an intuitive user interface with an interactive map based on OpenStreetMap. The article provides a detailed description of the system architecture, including the backend, database, and frontend implementation, along with the methods used to ensure performance and security. The result of this work is a functional web portal that provides up-to-date information on atmospheric air conditions, forecast data, and user-friendly visualization tools. The developed solution demonstrates high efficiency and can be scaled for use in other regions.

Keywords: environmental monitoring, air quality, web portal, forecasting, Django, Python, PostgreSQL, neural networks, OpenStreetMap

The article presents the compositions and technology of preparation of fine-grained concrete using modifying additives and superplasticizers. It is proposed to use waste from thermal power plants in the form of carbon black as a modifying additive. Depending on the amount of soot, parameters of the mobility of the mixture and indicators of compressive and flexural strength were determined. The optimal consumption of soot waste in the amount of 1.0% of the binder weight was established, at which the maximum parameters of the mobility of the mixture and the strength of fine-grained concrete were obtained. The complex effect of soot waste and super-plasticizer on the change in the physical and mechanical properties of concrete is considered. The combined use of soot and a plasticizing additive in a 1:1 ratio contributed to an increase in the mobility and tensile strength of the hardened fine-grained concrete during compression and flexural stress. The method of electromagnetic activation in a linear induction rotator was used to prepare dry mixtures.

Keywords: fine-grained concretes, soot waste, superplasticizer, electromechanical reinforcement, mobility, strength

The article describes the experience in the field of practice-oriented and career-oriented activities aimed at modernizing modern engineering education, taking into account an interdisciplinary approach. An example of training an engineer of a new formation based on school engineering classes is given. Attention is paid to project activities that can involve students in both creative and production projects. The issues of "career guidance filtering" necessary for selecting the necessary professional qualities of students through a cycle of mini introductory and training cases are highlighted. The emphasis is placed on the contact and information access of parents and schoolchildren to the university's research sector.

Keywords: management of engineering education, project activities, engineering classes, priority 2030, career guidance activities

This paper is devoted to the construction of a visual-inertial odometry system for an unmanned vehicle using both binocular cameras and inertial sensors as an information source, which would be able to simultaneously determine the vehicle's own position and the relative position of other road users. To ensure accurate and continuous localization, it is proposed to use an inertial navigation system and two types of image keypoints. Deep learning models are used to accurately and reliably track keypoints. To achieve efficient and reliable matching of objects between two frames, a multi-level data association mechanism is proposed that takes into account possible errors of various system components. The experimental results demonstrate the feasibility and application potential of the proposed system.

Keywords: multi-object visual-inertial odometry, localization, data association, tracking of 3D dynamic objects

This article presents the results of a study on the composition of decorative concrete that exhibits luminescence at night and architectural expressiveness in daylight, while maintaining enhanced physical and mechanical properties. The feasibility of producing decorative concrete using container and construction glass waste in combination with photoluminescent additives is demonstrated.

Keywords: concrete, decorative concrete, luminescent concrete, cullet, photoluminescent additives, plasticizing additive

This article evaluates various methods for determining the technical condition of structures, buildings and structures. To date, probabilistic (statistical) methods are considered to be one of the possible options for determining the degree of destruction of building structures. The advantage of these methods is the ability to comprehensively take into account the parameters present in a variety of material nature. This is due to the possibility of describing them in dimensionless quantities. The purpose of the method under consideration is to formulate a certain number of technical conditions (events) through which it is planned to determine the degree of destruction and find a set of technical conditions of building structures. Diagnostic matrices are created by combining diagnostic features and their conditional probabilities, acquired by analyzing a large amount of accumulated statistical data.

Keywords: construction and technical expertise, defects, reliability, diagnostic methods, efficiency

This paper is devoted to the construction of a robust visual-inertial odometry system for an unmanned vehicle using binocular cameras and inertial sensors as information sources.The system is based on a modified structure of the VINS-FUSION system. Two types of feature points and matching methods are used to better balance the quantity and quality of tracking points. To filter out incorrect matches of key points, it is proposed to use several different methods. Semantic and geometric information are combined to quickly remove dynamic objects. Keypoints of static objects are used to complement the tracking points. A multi-layer optimization mechanism is proposed to fully utilize all point matchings and improve the accuracy of motion estimation. The experimental results demonstrate the effectiveness of the system.

Keywords: robust visual-inertial odometry, localization, road scene, multi-level optimization mechanism

The purpose of the article: to determine the possibility of using file hash analysis using artificial neural networks to detect exploits in files. Research method: the search for exploits in files is carried out based on the analysis of Windows registry file hashes obtained by two hashing algorithms SHA-256 and SHA-512, using three types of artificial neural networks (direct propagation, recurrent, convolutional). The obtained result: the use of artificial neural networks in file hash analysis allows us to identify exploits or malicious records in files; the performance (accuracy) of artificial neural networks of direct propagation and with recurrent architecture are comparable to each other and are much more productive than convolutional neural networks; the longer the length of the file hash, the more reliably it is to identify an exploit in the file

Keywords: malware, exploit, neural networks, hashing, modeling

This article analyzes the specifics of applying certain circular economy principles in the construction industry. It examines the generation and management of construction waste. The main sources and types of construction waste are identified, including their classification by hazard level. It is determined that, due to its scale and the diversity of materials consumed, the construction industry has the greatest potential for waste utilization.

Keywords: construction industry, сlosed-loop economy, construction waste, waste recycling, waste disposal, circular economy