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  • Technical science. Informatics, computer facilities and management

  • Selecting a converter of aerodynamic forces and moments into the trajectory of motion for Simulink flight models of aircraft

    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

  • Identify and rank threats at a critical government facility

    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

  • On the variant of formalization of the task of extracting key skills and cluster analysis of vacancies in the implementation of a comprehensive digital career guidance toolkit

    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

  • Simplex methods for optimizing the composition of composite building materials

    The article discusses the use of simplex methods of experiment planning to determine the optimal composition of composite building materials. Composite building materials are multicomponent systems, so their properties depend on a large number of factors that are diverse in nature and influence. The use of orthogonal plans is not able to adequately describe experimental data with a wide range of varying factors. Therefore, the article proposes to use simplex-lattice Scheffe's plans. A complete third-order model was developed to determine the optimal composition of the filled cement composite, and a regression equation was written. The adequacy of the equation was confirmed at the control points of the plan using the Student's criterion. The proposed planning method can be used to optimize the composition of multicomponent systems.

    Keywords: multicomponent system, optimization methods, composite building material, experiment planning, simplex plans, Scheffe's polynomial, regression equation

  • Technical science. Building and architecture

  • Towards a method for calculating reinforced concrete flexible eccentrically compressed structures operating with large eccentricity

    This article presents a new developed calculation methodology, which includes provisions for standard calculations and takes into account the peculiarities of the operation of eccentrically compressed reinforced concrete structures operating at large eccentricities of load application. Adjustments have been made to the calculation methodology to take into account the following factors: the standard methodology uses the maximum tensile strength of reinforcement; proposals have been developed to determine the actual resistance of tensile reinforcement, which, in fact, will be significantly lower than the limit. Proposals are given that take into account the limiting deformations of concrete, which, in turn, will be a key quantity for determining the resistance of tensile reinforcement in the cross section. The article also presents the results of experimental studies of a flexible reinforced concrete pillar operating with a load eccentricity equal to e0 = 0.32h. Theoretical calculations and experimental studies were analyzed and appropriate conclusions were drawn.A formula has been developed to determine the real resistance of the stretched metal reinforcement at the time preceding destruction. The calculation algorithm has been compiled. When comparing theoretical and experimental strength, the difference did not exceed 5%.

    Keywords: steel, heavy concrete, reinforced concrete, testing, stand

  • Increasing the efficiency of organizational and technological support for the capital repair system at the present stage

    One of the tasks of the state is to create decent living conditions for the population, including providing people with high-quality and comfortable housing. However, over time, housing wears out, becomes outdated, and becomes unsuitable for use. In order to slow down and prevent rapid deterioration of capital construction projects, capital repair measures are being implemented. They are aimed at restoring and replacing structural elements of residential buildings that have fallen into disrepair. Overhaul of housing is a complex of organizational, technological and economic measures aimed at reducing and eliminating the physical deterioration of buildings. Thus, the creation of decent living conditions for the population and the safety of the housing stock, as well as increasing its energy efficiency, depend on the effectiveness of the organization of the capital repair system and its organizational and technological support.

    Keywords: major renovation, apartment building, repair and construction work, energy saving, energy efficiency

  • On normative regulation and perspectives of application of information modeling technologies in planning integrated development of territories

    The article considers domestic, foreign and international experience in the application of information modeling technologies (IMT) and its standardization in the planning of integrated development and information modeling (IM) of territories. The analysis of the world practice of standardization of TIM application in planning of complex development and information modeling of territories has revealed the absence of unified approaches and system representation in the part of development of standards in the subject area. Based on the results of the analysis and generalization of world practice recommendations and proposals for the development and updating of national standards and codes of practice in terms of the application of IMT in the planning of integrated development and information modeling of territories are developed.

    Keywords: information modeling, integrated development of territories, technical standards

  • Forecasting the risk of destruction of building structures

    The article is devoted to the assessment of signs that can lead to the destruction of building structures that undergo physical wear over time. The destruction of the elements can lead to adverse consequences. A mathematical basis is used to diagnose structural failure. With its help, it is possible to determine the influence of signs contributing to the destruction of the structure on the degree of destruction. This article discusses the main provisions of the general kinetic theory, as well as methods of its application in order to determine the emergency condition of structures. The technical condition of the structures is considered from the standpoint of the determinational theory. The concept is based on the principle of reliability of the structure before the first failure. The object's trouble-free operation model embodies the science of the speeds of processes in the field of structuring and decomposition of complex system structures throughout the life cycle and shows the adaptive response of structures to factors that shorten the service life of the object. This concept makes it possible to more accurately assess the risks of structural failure from the effects of certain adverse factors.

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

  • Assessment of manufacturability of assembly elements during the installation of a steel structure

    Methods for calculating technological and functional tolerances in the manufacture and installation of steel structures are described. An experimental installation of the structure was carried out to make it possible to clarify the tolerances, and the foundations of the methodology for assessing the qualitative and quantitative manufacturability of assembly elements were put forward to simplify the processes of manufacturing and assembling the structure.

    Keywords: methods for calculating tolerances, installation of a structure, manufacturing of structures, manufacturability, complex indicator of manufacturability

  • Water resistance of concrete fabric

    Increasing the energy efficiency of the construction process involves the use of materials with the lowest material intensity, including thickness, as well as with a reduced content of Portland cement clinker while maintaining or improving the technical characteristics of the products. In this regard, the use of textile concrete products, including concrete sheets, is promising. The development of a composite binder containing components that reduce nega-tive pressure in hardening concrete, and consequently shrinkage deformations and cracking, made it possible to obtain products with the following waterproofness indicators: determined by the ""wet spot"" method: 1.2 MPa; with a filtration coefficient of 5-7×10-11 cm / s; the concrete waterproof grade W12

    Keywords: textile-concrete, concrete web, water resistance, shrinkage during hardening, cracking, fine concrete

  • Mathematical modeling of heat transfer and hydrodynamics in models of ceramic honeycomb heat exchangers

    Using numerical modeling, we performed studies of the influence of the angle of inclination of the plates of the regenerative heat exchanger element on the heating time and pressure drop. The studies were conducted for models of heat exchange elements with lengths of 6 and 20 mm. Depending on the length of the element, the angle of inclination of the plates was: 10°, 20°, 30°, 40° (at L=6 mm) and 3°, 6°, 9°, 12° (at L=20 mm). At the boundary of the calculation area, the air flow velocity and temperature were established, namely 1 and 3 m/s, and 303 and 973 K. The research results demonstrated that increasing the angle of inclination of the plates helped reduce the heating time of the regenerator by 38.56-49.1%, depending on the length of the heat exchange element, the speed and temperature of the air flow.

    Keywords: heat recovery, honeycomb heat exchanger, numerical modeling, calculation, heating time, pressure drop, heat exchanger geometry, angle of plate, air flow velocity, air flow temperature

  • Automation of the competitive selection process for filling vacant positions of the University teaching staff

    The procedure for filling positions of teaching staff of universities belonging to the teaching staff is regulated by federal laws and local regulations. At the same time, it becomes necessary to store and exchange a large number of documents between various participants of competitive events. The aim of the work was to automate the process of holding competitive events and use a common data warehouse, with the help of which it is possible to speed up paperwork, save time and consumables, ensure the safety of storing, transmitting and processing information. The article reflects the obtained results of automation of the competitive selection process at the St. Petersburg State University of Architecture and Civil Engineering.

    Keywords: higher education institutions, competitive election, teaching staff, automation