DEVELOPMENT OF SOFTWARE FOR MODELING A NETWORK WITH INHOMOGENEOUS LOAD
S.A. Laptik, F.N. Abu-Abed
This paper devoted to the development of software designed to simulate networks with heterogeneous load, with further determination of the characteristics of network traffic. Traffic pulsations, inhomogeneities of application flow form an uneven load in computer networks. The process of modeling networks before their direct design is of paramount importance, respectively, the development of software (tool) for modeling networks is an important task. The development of algorithmic and software tools for modeling network traffic greatly simplifies the process of researching computer networks and contributes to the development of recommendations for further redistribution of load between network nodes. Each model under development has its own limitations and the reliability of probabilistic simulation results, which depend on the chosen mathematical apparatus, depends on them. The apparatus of queuing theory allows analyzing the results obtained at the level of their average values, and simulation modeling allows monitoring changes in network traffic over the entire simulation period for a set model time. The developed software is based on the modification of the already existing classical algorithm for calculating the performance of computer networks with heterogeneous traffic. The algorithm allows to optimize the values of parameters aimed at improving the performance indicators of networks with heterogeneous load.
Keywords: modeling, computer networks, network traffic, networks with non-uniform load, performance.
MULTI-METHOD APPROACH TO THE MODELING OF COMPLEX SYSTEMS BASED ON MONITORING DATA ANALYSIS
Y.E. Lvovich, A.V. Pitolin, G.P. Sapozhnikov
The article justifies the necessity of building various classes of mathematical models of complex systems as well as the relevance of a multi-method approach to the processing and modeling of monitoring and rating information, due to the variety of management tasks and resource efficiency optimization management of a non-profit educational organization in combination with rating management. The starting points are tentatively reduced sets of input indicators influencing the output indicators of a management unit functioning. It is based on time series forecasting on the base of additive and elementary functions. The dependence of the output performance on the input ones is determined by the regression model with the inclusion of time variables. The transition from a regression model to a neural network model is carried out, to improve the accuracy of forecasting for the purpose of managerial decision making at a certain planning horizon. The transformation procedure of initial time series into statistical samples of their prognostic estimates followed by randomized training sample development is proposed. The paper also demonstrates that the multi-method approach to the modelling provides a solution to a number of tasks concerning complex systems resource efficiency management.
Keywords: forecasting, modeling, management, resource efficiency, randomization
STRUCTURE OF THE TASKS OF MODELING, NUMERICAL METHODS AND SOFTWARE TOOLS OF OPTIMIZATION OF QUALITATIVE FUNCTIONING OF NETWORK OBJECTS IN MULTI-ASPECT ENVIRONMENT OF INFORMATION MONITORING
A characterization of the functioning of network objects in a multi-dimensional information monitoring environment is given. The main aspects of the evaluation of the quality of functioning in the conditions of digitalization are considered. The necessity of development of object-oriented methods of mathematical modeling and numerical optimization of the process under study is shown. The two-level nature of the orderliness of the elements of a multidimensional information monitoring environment and the possibility of their representation in the form of numeric sets are substantiated. The main classes of numeric sets transformations are given. The dependence of the majority of transformations on expert assessments in the interaction of the incorporation of network objects with the managing centre and consumers of the results of the operation are evaluated. The types of mathematical modeling and methods for their implementation that correspond to the transformations of the numeric sets: structural, statistical, expert-aggregation, expert-classification, expert-optimization are proposed. At the same time, expert optimization modeling is aimed at the sequential reduction of variants of qualitative functioning of network objects with the use of numerical methods of randomized search and expert evaluation.
Keywords: : network objects, high-quality functioning, information monitoring, numeric set, modeling, numerical optimization, expert evaluation.
MODELING OF HIGH-TEMPERATURE HEATING OF STEEL-FIBROBETON
UDC 53.072:691.32: 536.4
A.S. Molodaya, S.D. Nikolenko, S. A. Sazonova
The work is devoted to the problem of physical simulation of high-temperature impact on dispersed-reinforced concrete. The results of experimental studies of the behavior of fine-grained fine-grained concretes with metallic fiber (steel fiber-reinforced concrete), in the high-temperature effect modeled in the muffle furnace, are presented. The muffle furnace is selected on the basis of the required high-temperature exposure parameters. In particular, the maximum heating temperature, the rise time of the temperature to the required 8500C. All selected parameters are well correlated with the parameters of real fires. The medium of the working space of the muffle furnace when creating the temperature effect is air. One of the advantages of the selected muffle furnace is the ease of operation and sufficient stability of the maintained temperature. The technique of carrying out the experiment at different high-temperature effects on steel-fiber-reinforced concrete has been worked out. It is shown that the use of dispersed reinforcement in the form of metallic fibers improves the state of experimental samples after high-temperature exposure of a given level. It was revealed that the degree of influence of disperse reinforcement on the state of samples depends on the percentage of reinforcement and the magnitude of the temperature effect. It is shown that an increase in the time of high-temperature exposure affects the state of the samples. The results of the research will help further develop the process of physical simulation of high-temperature heating in the study of the properties of building materials.
Keywords: method of travel of queue, the method of finding an open, adaptive model, local adaptive management.
MODELING USING NOMOGRAM MAXIMUM PERMISSIBLE EMISSIONS
P.S. Kuprienko, V.J. Manohin, S.A. Sazonova
The article presents the results of modeling the maximum permissible emissions from production processes at asphalt plants. The aim of the research is to calculate the maximum allowable emissions from process industries in factories. To achieve this goal, a simple and easy-to-use nomogramm method was developed. Studies have shown that the developed method for determining the maximum permissible emissions, based on the use of straight and mesh monograms, can significantly reduce the labor intensity, as well as the cost and time of rationing emissions of pollutants into the atmosphere compared to the existing methods of calculation of maximum permissible emissions in the regulatory literature. The determined values of maximum permissible emissions are necessary for the assessment of the existing environmental situation at asphalt plants, for the development of measures to improve the environment and working conditions at hazardous and harmful industries. Verification of the proposed method was carried out not only by comparing with existing methods of calculation, as well as by comparing the results with the results presented in the finished draft standards of maximum permissible emissions at production facilities. As a result, the calculation of maximum permissible emissions in the projects according to the proposed method gave a deviation of no more than 8% compared with the corresponding data obtained by the method in the regulatory literature.
Keywords: modeling, nomogramms, maximum permissible emissions, asphalt plants, technological processes, environmental safety, labor safety.
MODELING OF THE RADIO-DYNAMIC SYSTEM IN MULTI-SERVICE COMMUNICATION NETWORKS
A.V. Ponachugin, I.V. Gusev
Telecommunications services are now widely used throughout the world. These services in the aggregate of individual multi-service networks. The problem of using telecommunications services is that it is not at all remote sites. And with this you can translate channels and communication lines. The purpose of the study is to create a radio access model to the resources of a multiservice communication network at the channel level. As a multiservice network, which provides such telecommunications services as: videoconferencing, IP telephony and data transmission. The network under investigation is built on the basis of the “Ethernet” technology, and a radio link using access, organized using one of the modern technologies of broadband wireless access. The received data presented on the site are presented in the following edition: In the MatLab software environment, the proposed radio access algorithm to the resources of the multiservice network at the second level of the reference model of the interaction of open systems (the channel level) is implemented. During the simulation, data were received on the load of the channel and on the number of delivered packets, which were displayed in the form of graphs. Based on the results of this study, it can be concluded that this model serves as an illustrative example of radio access research, showing that the result of the work, both successful and information packets are transferred between sources. The proposed model is of practical value, it is aimed at studying the influence of stochastic and deterministic processes that arise as third-party factors in the transmission of data over a radio channel, and also such a system, provided the radio access system.
Keywords: modeling, radio access system, multiservice network, radio access technologies, telecommunication services.
MODEL FOR CONTROL DYNAMIC OBJECTS
S.V. Ippolitov, О.N. Choporov, D.V. Lopatkin, A.V. Sizov
The work is devoted to the solution of the actual scientific and technical problem related to ensuring the required accuracy of control in a group in the automatic mode. The technique for synthesizing an algorithm for automatic control of fast moving dynamic objects in their joint motion based on the theory of covariance control is presented. The essence of the theory is to provide a given steady-state value of the covariance matrix of the state of a linear system by means of feedback. The approach is substantiated and a numerical algorithm for determining the achievable covariance matrix of the system formalizing the specified requirements for the accuracy of control in the group flight mode in terms of the RMS errors of the controlled parameters is developed. The numerical algorithm for solving the synthesis problem of an achievable covariance matrix is based on the method of solving linear matrix inequalities (LMI), using the cvx package of the Matlab system. A general linearized model of the relative motion in the group is developed, taking into account external perturbations of the turbulence of the atmosphere and the random wind and internal disturbances associated with the dynamics of the control system drives. To take into account the influence of a random wind, the Dryden model, which describes the turbulence of the atmosphere, is used. On the basis of the described mathematical model and the developed algorithm, numerical modeling is carried out to evaluate the accuracy of control under the influence of perturbations.
Keywords: dynamic objects, synthesis, algorithm, control, matrix, modeling.
THE PREDICTION AND OPTIMIZATION OF THE SYSTEM OF TRAINING IN THE FIELD OF OPERATION OF AIR TRANSPORT ON THE BASIS OF THE PRINCIPLES OF DUALITY AND EXPERT STATISTICAL MODELING
A. S. Borzova, V. G. Tsipenko
The paper discusses the challenge of improving the efficiency of the training system in the field of air transport. As the conceptual foundations of model-oriented approach to forecasting and optimization, this system is considered the principle of duality and multistep use of models. Optimization modeling is a partial implementation of the principle of duality due to the mechanisms of achieving efficiency of the training system: the reduction and transformation and the creation of the Bank’s professional activities on the one hand associated with the characterization of work functions in the professional standards, and with another – reflects the formalized components of educational resources that are aimed at the formation of certain competences of personnel in the field of operation of air transport. As the main form of statistical information defining changes in the training system, it is proposed to use a time series of volume indices of the needs of the labor market in specialists with higher education and graduating from universities. Specified approaches for the calculation of forecasting evaluations with different quality. After receiving the results of forecasting on the basis of expert information are invited to build valuation models and conduct selection method that has the highest priority for this model.
Keywords: optimization, training, air transport, modeling.
THE MULTIALTERNATIVE OPTIMIZATION IN THE FORMATION OF EDUCATIONAL
RESOURCES FOCUSED ON A MODEL OF PROFESSIONAL ACTIVITY
A. S. Borzova, V. G. Tsipenko
The principle of the multialternative choice models of professional activity of personnel training in the field of air transport is considered. The analysis of professional activity through the following categories: activities, job function, competence of the specialist in the field of air operations and the corresponding model of professional activity is carried out. Introduced variables characterizing multialternative choice of models and was given a mathematical formulation of the optimization problem. Considering a linear model of discrete optimization (the problem of minimum coverage), obtain the reduced set of models for a particular activity. The principle of optimal transformation models of professional activity in the components of educational programs. It is based on optimization models that transform the multiple models of professional activity with many components of educational programs. As optimization criterion was adopted the requirement for use in the educational program of the most important models.
Keywords: optimization, training, air transport, modeling.
THE SIMULATION OF RADIO WAVE SCATTERING ON THE STRUCTURES WITH ABSORBING LAYER
E. V. Aleshkina
This paper describes the problem of scattering of radio waves in a complex diffraction structure having a cut absorptive coating on part of its surface. The system of integral equations in the framework of it contact density potentials, green function and the initial frequency was formed. Once solved the system of equations with the application of the relevant basis functions based on the method of moments was calculated values of the effective area of scattering at given conditions of observation. Suggestions were made on how to form a subsystem of CAD, which will provide opportunities to conduct designing of equipment with the necessary values of the scattering characteristics. As input to this subsystem, you can apply the scattering structure, the sector of observation angles, the required value of the level for the characteristics of scattering of radio waves.
Keywords: scattering of radio waves, absorption, modeling, integral equation.