Proper cost estimation, monitoring and control is vital to the success of construction projects. BIM projects allow you to facilitate, visualize, and demonstrate work results. In the estimate documentation, BIM technologies also allow you to improve the process of working on a project. The article discusses the advantages of using BIM - programs for making estimates on the example of Avtodesk Revit and 5D estimates, indicates the main stages of work in these programs. Fewer errors and less lead time are key factors for integrating these technologies into construction pricing.
Keywords: BIM, estimate, 5D смета, construction, design, pricing
No major construction project is implemented without the involvement of contractors who perform significant work in the field of geodesy, design, equipment manufacturing, construction, control and commissioning of the object. In the conditions of market economy the existence of risk is inevitable for all participants in the construction project. Risks are one of the most serious problems of the customer, who needs to keep the limit of the estimated cost of a construction project unchanged. If negative external risks cannot be regulated, internal risks can be minimized or eliminated. Analysis of the experience of customers in the oil and gas industry of the Tyumen region draws attention to the relevance of the problem today. The article presents technical, financial, and organizational risks as the most common, and identifies ways to manage them.
Keywords: the customer's and contractor's responsibilities, risk insurance, reserve funds
The introduction and application of BIM-technologies has been associated with the transition of the industrial and civil construction industry to a higher level of competitiveness in many countries of the world . The article deals with the process of transition of the work of the project organization from traditional design to BIM modeling. The purpose of this article is to determine the advantages and disadvantages of the implementation of this technology in the activities of the project organization of the construction industry. The authors of this article propose scenarios for the implementation of BIM-technologies in the company's activities and made conclusions about using information technologies in construction organizations of different scale. The features of the implementation of this technology in the design process are considered. The stages of implementation of technologies in the activities of the project organization are analyzed. The result of this study is the conclusions on the subject under study.
Keywords: BIM technologies, information modeling, implementation, competitiveness, 3D-model, construction industry, BIM-standard, software systems, management, BIM-model
The use of a separate receiving antenna at different frequencies in parametric acoustic systems is associated with the irreversibility of nonlinear processes underlying its principle of operation. The paper considers the results of experimental and theoretical studies to assess the influence of external elements on the amplitude-frequency response of a piezoceramic acoustic antenna. The structural scheme of the experimental setup is considered. It is shown that parallel connection of an external inductance to a piezoelectric element allows shifting the antiresonance frequency of an acoustic antenna, which leads to an increase in both the signal amplitude at the antenna output and an increase in the complex resistance module at the operating frequency.
Keywords: acoustic antenna, the sensitivity of the receiving antenna, the amplitude-frequency characteristic, the modulus of the complex resistance
Method of hyperresonance desperation was applying for producing 4 types of organic nanopowders. We have discussed arias of application of such nano-powders.
Keywords: organic nano-powders, hyperresonance dispergator, application of organic nano-powders
The results of the development of a set of indicators for the quality of construction products on the example of a reinforced concrete pile are presented. The analysis of the requirements of regulatory documentation for the evaluation of aesthetic indicators of the product is carried out. A solution to the dispute between the Supplier and the Customer on the issue of assessing the quality of the concrete surface is proposed.
Keywords: quality management, improving competitiveness, consumer requirements, quality indicators, technical level, aesthetic indicators, construction
The article considered the propagation of a long impulse signal in a hydroacoustic waveguide. A solution is given for a replica of a impulse signal in the second approximation of the dispersion theory. The propagation of a single-mode and multimode impulse in a Pekeris waveguide with a bottom in the form of an absorbing half-space is simulated. The acoustic properties of the half-space correspond to medium sand with an average grain size 0,3 mm. The result of the solution in the second approximation of the dispersion theory is compared with the result of the simulation of the impulse replica obtained as a convolution of the input signal with the impulse response of the waveguide. The disadvantages of the solution in the second approximation of the dispersion theory are shown and analyzed. It is shown that the theory of dispersion incorrectly reproduces the transients when the signal is switched on and off in cases where the signal frequency lies near the critical frequency of the first or second mode. It is shown that the theory of dispersion correctly reproduces the envelope of a multimode impulse signal.
Keywords: impulse signal, normal modes, group velocity, dispersion theory, intramode dispersion, intermode dispersion
This article deals with the parametric hydrophone antenna arrays the elements of which are connected in parallel on one coordinate (in the columns). The mathematical models had been developed which were derived from the formula of the directional characteristic of a right-angled flat radiator embedded into the absolutely hard baffle. A level of overshoots of the directional characteristic (as related to a principal maximum) amounts no more than 0.15; a coefficient of decreasing overshoots of the directional characteristics because of shifting lines is approximately equal to two 2 for the array (8 x 8 or 16 x 16) with a pitch equal to wave length, with shifting lines to half the array pitch, a gap between the elements is 0.1 of the array pitch and a direction of beams is from 5 to 18 degrees on both sides with respect to the normal to an antenna plane. Without the gap between the elements at the abovementioned conditions the overshoots and the coefficient of their decreasing will no more than 0.1 and approximately 2.4 respectively. Thanks to extending the antenna array pitch a number of antenna elements is being reduced, and consequently, a number of the power amplifiers will be reduced as well. The simulation results are presented including computed two-dimensional directional characteristics of the antennae. The overshoot dependences upon beam direction and antenna array element dimension are also shown.
Keywords: hydroacoustis parametric antenna array, narrow sector of scanning, parametric, antenna, nonlinear, element, array, array pitch, directional characteristic, overshoot, overshoot level, increasing of array pitch
The results of studies of the structural and chemical properties of cobalt catalysts on zeolite HY support are presented. The samples were characterized by BET, TPR, TPD-H2, and IR-spectroscopy. It was found that these properties largely depend on the preparation method.
Keywords: Fischer-Tropsch synthesis, active surface, cobalt, zeolite, preparation method
A methodology for building an optimal enterprise architecture was developed to improve the efficiency of using information technologies in the digital industry, aimed at providing information support for production systems using modern integrated information technologies. The architecture is decomposed into a number of representations, which are chosen as invariant aspects determined by the analysis of various models of enterprise architecture. We propose to design of an information support subsystem for development of digital industry enterprise promising architecture as a practical tool. Its elements are formed in the field of information technology as a result, and a comprehensive indicator of the effectiveness of a given enterprise architecture is calculated. The modeled subsystem includes a module for storing and managing enterprise architecture elements, a module for storing and managing enterprise architecture selection criteria, a module for creating a promising enterprise architecture based on the implementation of its modeling algorithms, and a module for generating reports. The subsystem will enable the company to create the conditions for efficient creation and exploration of new types of scientific and technical products, timely to market these products, in particular, to ensure the export potential and import substitution and will reduce the duration of the production cycle, improve the effectiveness of in-service process equipment.
Keywords: enterprise architecture, digital industry, optimal enterprise architecture, information support subsystem
The stress-strain state of a two-phase body under the action of a load is described using a system of partial differential equations (Lame equations), the analytical solution of which can be obtained for a narrow class of problems. To apply one of the variational methods to solving the generalized Lamé system, a functional is written based on the potential energy of deformations, which allows us to expand the range of tasks for the study of mechanical processes in soil foundations under engineering structures.
Keywords: two-phase body, water-saturated soil base, potential energy of a two-phase body, stress-strain state
A model of passenger traffic movement is proposed that is suitable for identifying hidden patterns in the processes of passenger flow creation. The passenger flow is divided into four components, for which separate passenger flow submodels are developed: quasi-deterministic passenger flow from leaving stops to points of mass attraction of passengers; stochastic hourly passenger flow from each arrival stop to different districts of the city; stochastic flow that models the distribution of passengers between final stops in accordance with the degree of popularity of stops; chaotic distribution of passenger traffic between stops with a small number of daily visits. The results of calculations of the quasi-deterministic passenger traffic submodel from leaving stops to points of mass passenger attraction are estimated.
Keywords: passenger transport, passenger traffic models, passenger behavior patterns, modeling
One of the current tasks of operation of the linear part of the main pipelines is an adequate assessment of the degree of risk of pipe defects. There are several approaches to its solution and a set of calculation methods that take into account the specifics of the operation of main oil and gas pipelines. One of the main performance criteria of pipelines is their durability. The article describes a developed software product that allows you to automate the calculation of the maximum service life of a pipeline with a defect according to the chosen method.
Keywords: main pipelines, reliability, defects, strength, durability, program, calculation method, service life
The study is devoted to the analysis of satellite observations data assimilation to discover the necessary information for developing and verifying mathematical models of hydrodynamics and biological shallow-water kinetics. The use of satellite earth sensing data is taken to enhance information base. The possible use of neural networks with optical flow computation is considered in the study. The objective of the study is to develop a software tool used to identify the initial conditions in mathematical modeling of hydrobilogical shallow-water processes. The article illustrates the relevance of applying the observational data processing from satellite earth sensing. There are considered the necessity and possibility of using the neural network approach with the optical flow computation in solving problems of information processing from gray-scale snapshots.
Keywords: mathematical modeling, shallow water body, satellite sensing data, neural network, contour, image processing
The subject of research is the development of a service for searching through user files for a given set of keywords with parameters. The available approaches to solving such a problem were studied and the most relevant one was selected. The service searches inside files with text content in order to automate the process of selecting the desired files among the entire set. Its work is based on Porter's algorithm and uses a text stemming approach in order to obtain more accurate results. Searches for the stem of a word, taking morphology into account. Performing a morphological parsing of a word, a base is found common for all its grammatical forms, cutting off suffixes and endings. As a result, the algorithm of the service allows you to search not just for the given keywords, but also takes into account their word forms, and also searches for several sets of keywords at once, each set is analyzed separately. In addition, you can specify ranges of numeric values to search for. A feature of the service is that sets of keywords are searched together in nearby paragraphs within the range of -20 to +20 words from each other, thus taking into account the context of their appearance in the text. The service ranks the found documents according to the quality of their matching search criteria. Files in basic formats are processed: doc, xls, pdf, txt. The service operates on a Linux platform under the control of the Apache web server. Free software tools were used for development.
Keywords: search engine, document analysis, stemming, Porter's algorithm, word forms, morphology, arithmetic mean of percent, web service
The main process of stratum fluid extraction in Russia is mechanized lifting. It is observed that the stock of wells equipped with electric centrifugal pumps units has grown by 50% over the past 10 years, to almost 100,000 units. Growth detected in the average time between overhauls of the oil-well stock during this period increased by 50%, to almost 800 days. Mathematical modeling becomes a tool for further improving energy efficiency and reliability. The purposes of this work is to analyze existing models of submersible electric motors and their area of operations, identify existing shortcomings and limitations, and formulate requirements for the refined model and its application potential. The results of a thermоvisional inspecting of the rotor of a submersible electric motor after long-term operation in idle mode are presented. The temperature dispersion of the rotor packages is recorded from 36.68 °C to 46.67 °C. Different packages temperatures lead to uneven changes in the active resistances of the windings, which affect the contribution of each package to the integral operating and Electromechanical characteristics of the submersible motor. For taking into account the detected effect, it is proposed to model a submersible asynchronous electric motor as an electrotechnical complex consisting of an interacting and mutually influencing set of elementary electric machines. Spatial and mathematical models are presented that take into account temperature fluctuations in individual parts of the electric motor. The results of verification of the mathematical model are presented. Its validity in the field of applicability is shown.
Keywords: electric submersible motor, ESP, rotor pack, mathematical model, thermal processes
The results of the study of the operation of the tractor transmission МТЗ-82 in various gears are given. Simulink simulations are used to automate research calculations.
Keywords: transmission, tractor, simulation, Simulink
The article provides a solution to the problem of optimizing the frequency of maintenance on the example of the frame of a KamAZ-4308 truck. As an optimization criterion, it is proposed to use unit costs for a given time, including the costs of eliminating hidden failures. The calculation of the frame resource is carried out, the empirical and approximating functions of the general population of the finite volume are obtained.
Keywords: car, probability of uptime, maintenance, optimization, unit costs, reliability assessment
The synthesis of phase-locked frequency systems is based on a two-stage optimization procedure. This makes it possible to apply the combined maximum principle to construct a model of the signal phase dynamics under conditions of structural uncertainty of regular effects. The estimation equations in the form of a two-point boundary value problem are obtained using the discrete maximum principle Of L. S. Pontryagin, and a recurrent estimation algorithm is obtained using the invariant immersion method. The efficiency of the synthesized phase-locked frequency system was evaluated on the basis of mathematical modeling in comparison with the traditional one by the criteria of convergence rate and accuracy.
Keywords: synthesis, phase auto-tuning of frequency, the maximum principle of L. S. Pontryagin, the maximum condition of the generalized power function
During the modernization of the cement plant and the transition to a new technology for the pro-duction of cement, the design of the divider for the flow of bulk materials was set as one of the tasks. In the future, with the successful implementation of the project, this would make it possible to use a common raw material warehouse that feeds two clinker kilns. The compiled mathematical model of the raw material flow divider made it possible to simulate transient processes in the op-eration of the mechanism. The created program and visualization of the process simplifies the work of the personnel operating the installation.
Keywords: automation, operation, divider, modernization, cement industry
To share and transfer knowledge, they must be presented in an explicit form that is understandable to both humans and computers. The paper proposes an approach to ontological modeling of WHAT-knowledge, which allows representing knowledge simultaneously in two forms: a) in the form of a visual model (ORM2-diagram), understandable to humans, and b) OWL2-ontology, computer understandable. To convert the knowledge representation from one form to another one, it is proposed to use ontological patterns (mapping rules). Currently, there is no software toolkit that allows a) to build an ORM2-diagram and mapping it in the OWL2-ontology, and b) based on OWL2-ontology, build a visual model in the form of an ORM2-diagram. Therefore, we are developing a Protege-plugin, which should provide a) the creation and editing of WHAT-knowledge by building an ORM2-diagram and mapping it in the OWL2-ontology, and b) visualization of WHAT knowledge in the form of an ORM2-diagram, extracting instances of ontological patterns from the OWL2-ontology. The paper provides a functional and structural description of the plugin; examples of its use are given.
Keywords: WHAT-knowledge, explicit knowledge representation, ontological modeling, ontology, visual model, intermediate model, ontological pattern, ORM2-diagram
.The article discusses methods and means for monitoring weld defects. The types of defects and their impact on the performance of the product are listed. It has been shown that the ultrasonic method is best suited for testing the seams of pipe fittings. On the basis of the analysis of the design and the principle of operation of the ultrasonic flaw detector, a technique for automated control of defects has been developed. The results of control according to the written method are provided. Further ways of automation of the UCD-50 IPS flaw detector and its analogs are described.
Keywords: weld seam, defect, ultrasonic testing, ultrasonic flaw detector, pipeline fittings, non-destructive testing, software