The results of optimizing the composition of concrete based on aggregates from crushed concrete are presented. With the help of mathematical and natural modeling matched the composition of the expanding agents sulfoaluminate type, the optimal percentage of components of the modified cement required for producing a material with improved performance characteristics, the mathematical model construction and technical properties of the concrete and the kinetics of their changes to take into account the time factor and strength and weathering.
Keywords: mathematical modeling, expanding additive, factor experiment, influencing factors, level of variation, experiment planning matrix
The article is devoted to the study of the interaction violations of electric locomotives current collectors with a contact wire, accompanied by the appearance of an electric arc. In order to further develop the system of technical diagnostics of current collection disruptions, accompanied by arcing, it is necessary to study the nature and parameters of the processes that occur with these disruptions. The main part of the article is devoted to the determination of the geometric parameters of the heating zone of the contact wire material by a movable electric arc, followed by an analysis of the applicability of the obtained dependences and their normalization. The description of the research area, the essence of the problem and the main statements of the technical diagnosis of current collection disruptions is given. The nature of the distribution of heat in the cross-section of the contact wire is shown. Based on the nature of the process and plane geometry, the parameters of the heating zone of the contact wire material are obtained: the area of the heating zone and the depth of the heating zone. Limitations in the application of the obtained dependencies are given.
Keywords: electric transport, overhead contact system, contact wire, current collection disruption, electric arc, current collection with arcing, thermal wear, softening, diagnostics
The consideration and study of the process of functioning of the offices of the company were the following objectives. Determine the quantitative dependencies of the input flow of patients and unserved requests (refusals). To conduct the sensitivity analysis. Build a basic model of a dental company as a simulation model (input model) that provides targeted variation of input parameters, and a linear programming model (output model) that processes simulation results and provides data on the degree of sensitivity of the model to changes in its parameters. Compare two simulation models of a dental company with different numbers of doctors. Determine the most effective model. Determine a combination of management variables in the optimization model that takes into account the amount of estimated lost profits due to rejection of applications, and based on this, make a conclusion about the need to hire additional employees, thereby increasing the profitability of the dental company. To achieve these goals, the following tasks were solved. A simulation model of a dental company as a Queuing system in the GPSS language was developed and studied. It is determined under which parameters the model is most effective. An analysis of the sensitivity of the model to changes in its parameters is performed. Numerical Monte Carlo methods were used to investigate this issue. We have developed a custom application in the VBA object-oriented programming language that allows you to determine for a certain period of time, starting with how many failures, you should hire an additional doctor, so that the company's profit is maximized. The practical value of the proposed model lies in its flexibility, complex nature, and consistency in the organization and technological regulation of the company's main systems and business processes. The model of a dental company has a sufficient degree of universality, as it can be used in any branch of the service sector. more complicated when you add players. The term "truel" we understand the rivalry three players. They are assigned some values of accuracy the probabilities of eliminating the opponent in one shot. At each stage of the game is chosen by the active player (the selection rule active player either randomly or by prior agreement between the players about their participation). The active player chooses an opponent to eliminate or passes the course. Developed mathematical models for different formulations of the conditions of the game (random or fixed choice of the active player). For each model are analyzed based on the probability of winning in the "truly" of accuracy, based on randomly generated program values. Comparing analytical solution and simulation, we see that they have the same answers. For large dimensions similar games analytical method requires complex calculations, so an acceptable alternative is the simulation method. Data research nahegelegenen in political and judicial practices, as well as analytical tools for the study of the theory of evolution.
Keywords: simulation model, Queuing systems, GPSS World, linear programming model, Monte Carlo numerical methods, VBA
The use of spacecraft identification systems can increase the informational secrecy of low-orbit spacecraft constellations. However, existing methods of recognizing "friend or foe" do not provide high cryptographic strength, and authentication protocols with zero disclosure are time-consuming. This drawback can be eliminated through the use of Polynomial Residue Number Systems (PRNS) that allows parallel computing in the protocol. Therefore, the development of a high-speed authentication protocol with zero disclosure is an urgent task. The purpose of the work is to reduce the time required to calculate the status of the satellite through the use of PRNS
Keywords: authentication method, spacecraft authentication protocol, Polynomial Residue Number Systems
"The article is devoted to solving the problem in the field of development of methods and means of automation of evaluation of training efficiency on computer simulators, which are used for the training of operators of production processes. Approaches to assessing the effectiveness of training are given in many scientific studies on the creation and application of computer simulators. However, the problem of automation of the process of this assessment on the basis of the simulators themselves is not sufficiently considered. The evaluation methodology (based on mathematical statistics methods) and the prototype subsystem of the computer simulator complex were proposed to solve the indicated problem. They reduce the effort of the expert responsible for performance evaluation. Output results can be used for training operators in educational organizations. The reported study was funded by RFBR according to the research project № 18-38-00835. "
Keywords: computer simulator, mathematical statistics methods, efficiency of training process, automation of training process
A survey of the frame-panel building was carried out, in which ecowool was used as the heat-insulating material. A study was made of the moisture state of wooden frame walls and attic floors. Ecowool samples were taken from various sections of the wall. No mold was detected on material samples. In this case, the sorption humidity was not more than 16%. The results of laboratory tests of ecowool showed high persistence of density and coefficient of thermal conductivity during long-term operation. Tests were conducted to determine the effect of moisture on the change in the physical and technical properties of ecowool. The research results were processed by statistical methods. As a result of the study, it was found that moisture does not accumulate in the ecowool layer of the examined frame walls and attic flooring, but goes out through the insulation and elements of the building envelope. The conducted studies allow us to predict the preservation of the heat-shielding properties of ecowool during operation for a long time
Keywords: ecowool, durability, sorption humidity, density, coefficient of thermal conductivity
The huge part of Russia territory is located in the permafrost zone. Mastering of this area is important step for Russia, because the mining is developing at a rapid pace, and mostly oil and gas. There is its own specificity in the construction of buildings and structures on permafrost. Peculiar properties of foundation in the permafrost zone are considered in this article.
Keywords: foundation, permafrost, thermosyphon, oil storage, oil and gas industry, drilling, ammonia
The work is devoted to the study of the main aspects of the use of expert systems in the metallurgy industry. An overview of current production problems is given, as well as prospects for the development of automatic decision-making systems based on formalized expert knowledge using modern data processing tools
Keywords: production processes, metallurgy, control actions, expert systems, technological personnel, production indicators, software implementation, modeling, interference, training complexes
The article presents a program of comprehensive construction and technical expertise of the structures of an industrial building. The features of the construction and technical expertise of the structures of the agricultural warehouse of mineral fertilizers are described. An algorithm of the sequence of actions for the technical expertise of the structures of the object is developed. Measures have been developed to repair and restore the working condition of damaged structures
Keywords: construction and technical expertise, defects, bearing capacity, structural repair, property management
The publication is devoted to the task of developing a demo-genetic model of the adaptation of pests to transgenic and hybrid agricultural crops, taking into account the type of taxis. An assumption is introduced that the dynamics of hybrid agricultural crops can be investigated using demo-genetic models. A description of the problem is given in accordance with the characteristics of the growth of biomass of agricultural crops and the dynamics of pests, as well as taxis species. The modeling of the processes of fast and slow taxis depending on the behavior of pests at a particular point in time is described in detail, taking into account the type of their genotypes that affect the acquisition of mutations. The paper describes the features of the physiological structure and life cycle of insect pests, affecting the prediction of their spatial concentration and, accordingly, the prediction of productivity; the possibilities of their application in mathematical modeling.
Keywords: demo-genetic model, taxis, transgenic agriculture, hybrid, pest, biomass, diffusion
This work outlines software packages that are capable of dealing with nonlinearity of the analyzing structure. Brief introduction of the software and its beginning in the history. Also explained the difference of linear and nonlinear analysis performed on the structure. Defined which software packages are for media and analyzing problem (structure). Similarly, descriptive study was done to understand advantages and disadvantages of main analyzing tools ANSYS, ABAQUS, SOLIDWORKS. In addition, the work looked into which one of the mentioned tools have its own distinguish functions. Finally, the results data of all three software were compared with each other.
Keywords: nonlinear analysis, numerical analysis, ANSYS, ABAQUS, SOLIDWORKS
This article presents the results of studies on the possible use of hoisting-and-transport rope complexes in the aftermath of emergency and environmental situations. The advantages of using self-propelled transport and freight carriages based on soft pneumatic bearings for rescue operations are considered. An algorithm is described for a software package designed to automate the process control of a freight-carriage used to lift and move cargo at predetermined coordinates. To implement the functioning of the software package, a processing technique was used for incoming and outgoing data, input and output streams, data collection centers using Java TCP / IP technology. An example of a graphical interface of the software.
Keywords: software package, control automation, hoisting and transport mechanism, protocol, JAVA, algorithm, environmental consequences, cable system, local coordinates
It is shown that in the analysis of self-determination it is expedient to use the tools of cognitive modeling. This allows us to identify all the cause-and-effect relationships that provide logical and semantic focus on the desired (target) result of a particular system. The problem of analysis is a special case of the study of the fundamental philosophical category of development, as the relationship and interaction of "things, properties and relations". Formally, the analysis can be reduced to the procedure of semantic and causal interpretation of the original cognitive model. The model allows to study the internal structural organizations that affect the implementation of self-determination of the system. Analysis of self-determination in turn opens the way to effective cognitive modeling, construction of dynamic models, application of game and scenario analysis methods.
Keywords: cognitive analysis, cognitive model, structure, system, self-determination, management, interpretation
The work has formulated a justification for the necessity to perform works aimed at solving the tasks of providing technological preparation of composite structures production by means of automation based on the application of modern information and computing systems. The characteristics and key aspects that determine the efficiency of automation at the stage of technological preparation of production are highlighted. Justification of the relationship between the processes determining the process formation and its efficiency is given
Keywords: automation, technological process, technological preparation of production, composite materials, composite designs, neural networks, modeling, process parameters
The analysis of the existing system of export traffic management in the port transport and technological system of the region. The issues of violations of the terms of delivery of goods on the railway network and in the regional context are considered. The statistics of the trains left behind from the movement on the range of the railroads is studied. On the example of the North Caucasian railway (SKZHD) serving the ports of the Azov-black sea basin and consignees of the southern region, the issues of coordinated delivery of goods are considered. A systematic presentation of the issues of application and development of modern logistics and information technologies to solve the problems of management, planning and optimization of export traffic in rail and sea traffic is given. The analysis of the implementation of the main tasks solved with the help of Traffic information and logistic system (DILS) control unit Road logistics center (DLC) SKZHD.
Keywords: Analysis, delivery time, reliability of delivery, railway transport, seaport, financial risk, transport services, competitiveness