Currently, great importance is given to the use of mathematical modeling in the conduct of system analysis. The article reveals the definitions of system analysis and mathematical modeling. Problems that can be solved with the help of system analysis are described, and the main tasks of system analysis are formulated. It is noted that system analysis is used mainly for research and design of large and complex systems. The methodological bases for the development of a mathematical model are analyzed.

Keywords: system analysis; model; system; math modeling; mathematical model

At the moment one of the most advanced flexible methodologies IT project management is SCRUM technology. Its feature is the partition of the whole work on short iterations (sprints), each of which represents a cyclic process, repeated all the way through the product development process. This allows you to constantly monitor the emerging risks and minimize them effects. Each sprint starts with planning, which sets the pace of work and stimulates high performance. The key point of planning is predicting the level of focus of the team on the implementation of the tasks, the so-called focus factor. It is the ratio productivity to labor intensity. The paper presents the results of numerical experiments to identify the best methods for predicting this indicator. In their the production data of one of the project groups of the real commercial firm in the field of IT. Extrapolation forecasting methods with a sliding base on the previous actual results. At the same time, the width of the base one to seven previous periods), and the type of extrapolating function. Approximating polynomials of zero, first and second degree are considered. Attention has also been paid to the method of exponential smoothing and Bayesian approach to diagnosis and prediction. For the integral the quality of forecasting used the value of the root-mean-square relative performance error. According to the results of the experiments, three optimal variants are selected. The first is the forecast for the sliding arithmetic average of the actual focus-factors for 3-4 previous periods. In the second variant, again, the sliding the average of actual focus factors for 3-5 sprints, but not arithmetic, and geometric. The third method for predicting is the product theoretical focus factor on the actual. We use the geometric mean it per the 1-2 sprints. In the mean square norm for both methods, the prediction error is the same, about 5.8%. If we estimate it not by the mean square metric, but by maximum deviation, then the latter option is slightly better. Results are intended to clarify the intuitive planning of sprints when performing real projects.

Keywords: management, IT-project, SCRUM technology, sprint planning, forecast, focus factor, moving average, linear and quadratic regression, exponential smoothing, Bayesian approach, root-mean-square error, the best possible option

The task of this work is a survey of passenger correspondence, a traffic intensity survey ,a passenger traffic survey of the road net on the example of Sochi. Used methods: passenger correspondence polling by questionnaire, statistical analysis for the array of correspondence processing, observation, registration and analysis of traffic and passenger intensity.

Keywords: passenger correspondence, traffic, public transport, passenger traffic

One of the key points of planning individual iterations in IT projects is the forecasting of the so-called focus factor. More specifically, it is the concentration of the workforce and the team's efforts to perform tasks. The purpose of this work was to clarify the previously obtained results on the choice of optimal methods of such prediction. This used another criterion for the quality of the forecast, not a mistake in planning the performance of the iteration, as before, and the inaccuracy of the prediction of the focus factor. The analysis carried out according to the new criterion fully confirms all the results obtained earlier. Among the considered mathematical methods of forecasting for planning in iterations of IT-projects the most suitable is extrapolation by moving average (both arithmetic and geometric) for the previous 1-4 periods. The error of the focus factor forecast for them is about 4.7%. Another aim of this work was the formalization of the intuitive methods of planning undertaken by specific teams of developers of projects. On this basis, within the framework of the theory of fuzzy sets with the use of linguistic variables, a heuristic forecasting model is developed. Numerical experiments on the basis of specific production data have shown for it a higher accuracy of the forecast than for extrapolation. The error was about 3% against 4.7%. The paper also presents a combined model using elements of both the heuristic approach and the above-mentioned extrapolation. It showed even higher accuracy of the forecast, with a mean square error of about 1.5%. The results obtained in this work, in our opinion, completely solve the problem of the optimal method of planning individual iterations in the implementation of IT projects.

Keywords: management, IT-project, iterative nature, iteration planning, forecast, focus factor, moving average, standard error, linguistic variables, fuzzy analysis, heuristic model

Diffraction characteristics of the gratings are calculated by two methods - method of approximate boundary conditions and a strict method based on the numerical and analytical solution of the two-dimensional integro-differential equation. Results of the graphene diffraction gratings calculations are presented.

Keywords: graphene, graphene gratings, volume integral equations, plasmons, coefficient of reflection

The article presents an analysis of the causes of deformation of the steel tank, built on weak water-saturated highly compressible clay soils. The results of calculations of the soil base deformation and comparison with the data of geodetic observations are presented

Keywords: Foundation, steel tank, soil, hydraulic testing, deformation, inclination, settlement

In the present article examples of improvement of ecological indicators in the conditions of dense building of the city are reviewed, the principles of territorial planning are described. Detailed studying of environmental problems of the city, a way of their decision is carried out, the most optimum mechanism of a solution is revealed. This article gives the chance will get acquainted with result of numerous researches in the field of modernization of an ecological framework of the city, the most suitable and elementary actions in the realization increasing the area of city "green zones" in the conditions of dense pointed building are given. Having analysed the studied material, conclusions by the given examples are drawn.

Keywords: ecological equilibrium, the urbanized territory, gardening of the city, vertical gardening, mobile gardening

This work is devoted to the automatic generation of verification sets of test procedures; the proposed and developed algorithm for selecting trial solutions for solving the problems of satisfiability of Boolean formulas.

Keywords: test sets, automatic generation, solver, Boolean constraints

The article presents the analysis of the grain market in the Russian Federation. Data are given on grain yield of crops for crop years 2016 and 2017. Considered the technology of grain terminals in Novorossiysk sea commercial port. The scheme of the grain. The analysis of the importation of grain cargoes by railway and motor transport.

Keywords: Grains cargoes, analysis of the market of grain exports, the port, grain terminals, rail transport, road transport

in the article the questions of modeling of thermal effects in vortex tubes with application software, for example, CFD-complex is Studied. Discusses the practical applications of thermal effect in vortex tubes, is proposed using the process of refrigeration in vortex tubes for climate control in vegetable stores with the aim of improving the safety of the products. This article is of interest to a wide circle of readers, dealing with issues of simulation software packages.

Keywords: heat effect, cooling, heating, microclimate, modeling, CAD software program, 3D model. CFD-complex is Studied, FlowVision

The study of the method errors depending on the choice of numerical approximation of the linguistic variables used is proposed. It is obtained that the necessary condition for the absence of objective (independent from the opinions of experts) reasons for the inconsistency of paired comparison matrices is the closure of the numerical scale relative to the composition of estimates. . In particular, for the classical Analytic Hierarchy Process coming from the works of A. Saati, such a scale is not closed. When the criteria of one level of hierarchy are not the same in terms of priorities relative to the overlying goals (and this situation often happens), even one expert Advisor, in principle, cannot give a consistent matrix of paired ratings. What, in fact, is due to the great attention in the classical considered technology to the methods of estimating inconsistency of the matrix of paired comparisons and its minimization. As the number of experts increases, this effect increases. A closed evaluation scale can be obtained from successive degrees of one any number. For purposes of powers of a number is 1.5, although not ruled out another choice. Для таких шкал объективные причины возникновения несогласованности матицы парных сравнений отсутствуют, а субъективные, связанные с несогласованностью мнений эксперта, могут быть устранены в процессе формирования оценок. The proposed method is explained by a concrete example of the use of the hierarchy analysis method in the assessment of personnel risks in small non-commercial projects.

Keywords: Analytic Hierarchy Process, expert evaluation, evaluation scale, matrix of paired comparisons, violation of transitivity, objective reasons for inconsistency, isolation relative to the composition, AT-projects, personnel risks

The article examines factors evaluation of level of competitiveness of a specialist in the field of communications, in three groups, physiological, personal and professional-qualification potential. Assessment of competitiveness of the personnel included: the formation of complex indicators of competitiveness assessment of staff taking into account specificity of activity; determination of the relative weight of importance of parameter groups; definition of the integral index of competitiveness of the personnel in comparison with the "ideal basis of comparison." A comparison of key parameters of competitiveness of civil servants and experts in the field of communications and the commercial sphere.

Keywords: personnel competitiveness, assessment of competitiveness of the personnel, the factors of competitiveness of a specialist sphere of communications

This paper presents an analysis of domestic and international experience in the construction of modern non-rigid pavements. An assessment of existing structures on roads with high traffic volume; designated directory structure of non-rigid pavements, developed on the basis of the research.

Keywords: construction, non-rigid pavement, structural layers, the total number of rated load applications, traffic load class

In the article a method for analyzing the characteristics of materials is considered, with the possibility of more accurate measurement by typical measuring instruments. Modled computer models of tees with different types of wave propagation are considered. Also talk about the design of the models created and an analysis of the results obtained on the study of the characteristics of materials, with the possibility of more accurate measurement by typical measuring instruments.

Keywords: Microwave, VHF wave, the centimeter wave range, waveguide tee, coaxial tee, resonance method

Based on our own, as well as literary experimental data, the analysis of the Influence of a barrier material used to create heterogeneous composites based on La0.7Sr0.3MnO3 on their magnetoresistive properties is carried out. Such composites differ in existence of an isotropic negative magnitorezistivnost (MR) connected from backs - dependent tunneling of carriers in magnetic field. The largest value MR up to 15% in the field of 15 kOe are shown when using glass-like GeO2 oxide at a percolation ratio of components.

Keywords: lanthanum strontium manganite, composite material, ceramics, one-step synthesis, magnetoresistance, percolation threshold, dielectric constant, barrier layer, tunneling, spin polarization