Papers by Keyword: Mathematical Model

Abstract: The applicability of the method mechanoelectrical transformations (MET) to determine the depth of the macrodefects location in the sample on parameters of the electromagnetic response is evaluated. As the response parameter it was used the phase characteristic of the signal analytical representation.On the one-dimensional mathematical model it was shown the possibility to detect phase response changes when reflected from defect acoustic wave is mixed with the signal spurious component generated by a distributed MET sources. Experimental verification of mathematical model on a sample of concrete was conducted. It has been shown that the sensitivity of the method MET to evaluation of the macrodefect locate depth depends on the wavelength of the excitation pulse and the area of the macrodefect border closest to the emitter-receiver system.

Abstract: The work considers mathematical models describing thermal processes in the framework of thermal processing of raw material mixture for cellular glass sponging. It is shown that the existing models do not completely reflect the physical processes occurring in the technology of cellular glass production. It is noted that kinetics of cell formation in cellular glass is a promising trend for improving the cellular glass technology.

Abstract: A mathematical model for the passage of a light stream into a room through zenith, rectangular, shed lamps and obliquely arranged light devices is developed. The use of the mathematical model will increase the accuracy of the quantitative estimation of the light regime of the room in the annual cycle, as well as the transition to a differentiated account of the light climate.

Abstract: The authors consider the residential real estate market as a complex socio-technical system, for the prediction of which it is advisable to use a combination of classical methods of forecasting and soft computing or intelligent data processing. The development forecast of the residential real estate services market with the help of foresight technologies is made. We performed the analysis and identified the main factors acting in the market, and their impact on the development of market trends. A mathematical model of residential real estate value forecasting based on the theory of fuzzy sets is developed.

Abstract: Construction project involves a complex array of specific interdependent activities, undertaken by multiple participants with contradictions of interests. It has phases to follow in its life cycle to meet the project’s objectives. Each phase will typically have multiple sub-phases and processes. The choice of technological and organizational solutions is carried out in the planning and design phase. Changes affecting any task (or the need to resolve conflicting elements of two or more tasks) can have a significant knock-on effect on the project’s success, regardless of the phase of the life cycle. This paper intends to develop an integral model of organizational and technological solutions, which allows to choose the optimal criteria for Burundian capital master plan as well as monitoring the quality of their implementation.

Abstract: One of the key objectives of the formation and development of integrated business structures in Russia is to meet the population's need for new housing. Qualitative and quantitative indicators of residential building commissioning are significantly influenced by demand and supply factors. With the purpose of forecasting the activity of demand in the housing market with the help of methods of economic and mathematical modeling, the interrelation system of factors forming the socio-economic basis for the development of integrated business structures in construction has been built. The formulated economic and mathematical model allowed us to identify the factors focused on the formation of rational relations between the subjects of the housing and construction cluster. The model shows that the effectiveness of the mortgage lending system (from the demand side) and the level of introduction of innovations in the investment and construction complex (from the supply side) have a decisive influence on the solution of the housing problem.

Abstract: Presently constructors use peristaltic concrete pumps for wet shotcreting processes or for transferring the building mixes to the place of their deposit. Fitting the flexible-hose concrete pump with a hydraulic drive allows both making the range of its operating modes much broader and enhancing its reliability. Numerically simulated models of the building mixes feeding processes were developed to design a hydraulic drive to fit the general-service flexible-hose concrete pump and to calculate its basic parameters. Simulation of the building mixes feeding processes gave the characteristic curves of the concrete pump operating parameters, determined the time of ramping the concrete pump up to the steady running mode, and estimated the impact of the transferred mix density and viscosity to the maximal system pressure, supplied power and torque values.

Abstract: The article describes the touch probing system with the strain gage as the main measuring element. The device has small geometric dimensions and it was developed to measure the gas turbine engine compressor blades. To select the optimum configuration of the probing system, mathematical models of two principal configurations were developed. Simulation modeling of the force of the measured surface impact on the measuring tip was carried out in the Ansys environment for these assemblies. On the basis of practical experiments, the diagram of the deviation of the probe on the resistance of the strain gage was constructed. Reference element were measured to determine the accuracy of the designed touch probing system.

Abstract: This paper presents an analysis of the rainwater flow on the final cover slopes of an urban landfill so as to ensure the drainage of infiltrate water through the drainage layer applied across the geomembrane of cover layer, with a runoff coefficient as low as possible. It is presented a calculation model for the transmissivity of the drainage layer depending on the thickness and on its hydraulic characteristics and also on the topsoil layer applied to the surface, as well as depending on the coating slope length. This calculation is made for both a side with a single slope (tilt) as well as for sides with two slopes. Also it is presented a mathematical model for the hydraulic calculation of surface water drainage ditches drained through the drainage layers, but also through the surface runoff, in order to establish the optimal drainage section.

Abstract: This study investigated optimum design methods for frame buildings with focus on minimization of economic costs. The methods discussed are intended to provide sufficient reserves for reliability of load-bearing steel structures. The analyzed mathematical models enable to assess seismic resistance of a structure and implement optimum design methods according to the selected key criterion. The available mathematical models assessing economic efficiency of metalwork reinforcement need further development. The model based on the principle of balanced risk is considered as the most appropriate for the study of structural reliability for industrial buildings. This model allows to assess the expected damage as compared with the initial spending on seismic protection. The focus is on setting and implementation of the task whose limiting condition provides equality between expenditures for reinforcement of damaged steel structures and those for damage prevention activities. Minimum of economic costs for construction or reconstruction of a structure is taken as the optimality criterion. This takes into account accumulation of damages within the standard life cycle and changes in stiffness of materials. Assessment of damage risk is based on the life cycle of a structure, its seismic resistance class and spending on damage repair. The study suggests a number of structural solutions that enable to reduce deformation of steel parts of the frame.