Variant Of Construction Research Articles

Optimization of the technological process and equipment of complex profiled parts

The modernization of the manufacturing industry requires the development of the manufacturing process and technological equipment, in general, but also for the realization of the complex parts. These components with complex geometries and multiple functional roles, for the most part, are safety parts manufactured from materials with superior physicochemical characteristics that have demanding technical quotas and conditions, leading to difficulties in establishing the processing methods and technological equipment used. For those considerations, it is proposed a three-stage design-optimization algorithm and an additional step, which represents a balanced and rational approach to technological process issues and in the manufacturing system. The first stage shall determine the optimal number and succession of operations based on a technological graph and the associated mathematical model, in which the objective function and the restrictions are defined concerning the purpose pursued. The second stage establishes, for each technological operation, the optimal orientation and fixation scheme (O-OFS) of the semi-finished part, which ensures the precision of machining and the technological process productivity, applying elements, of the sets theory and the global utility method to the method of optimizing of orientation and fixation of the parts. In the third step, based on the optimal orientation and fixation scheme, a mathematical model is formulated for the adapted technology chart to describe the construction variants of the orientation supports, and to provide the optimal device construction solution to the analysed operation. In situations where a reconfiguration of the technological system is desired, the fourth step of equipment optimization of the entire technological process is proposed.

New methods and equipment for the machining of cross-axes parts- Case study

The processes and equipment for manufacturing, assembly, and control operations, adapted to the needs of modern industry, shall be determined according to the volume of production and the technical conditions imposed, at a level which ensures economic effects on the recovery of costs for their design and execution. The design-optimization algorithm, with the four working steps, applied on the case study presented, allows the determination of the optimal number and succession of technological processes, but also of new processing methods, based on a technological graph and optimization criteria. In the second step, determine for each technological operation the optimal orientation and fixation scheme of the analyzed part, combining elements of the set theory and the global utility method, with a method of simultaneous optimization of the orientation and fixation fundamentals for two different transformation areas with distinct quotas and conditions that need to be achieved. In the third step, is identified and analyzed several construction variants of structures for the equipment. By formulating a technologically adapted graph to describe structures of orientations, but also other structures, is obtained an associated mathematical model and optimization criteria for the optimum design variant of the orientation and fixation at the analyzed operation. When is desired a complete appreciation of all the technological operations, the fourth step of system optimization is proposed, which is also based on a technology graph and an associated mathematical model adapted to the evaluation of the analyzed types of equipment.

ВИБІР І ОБҐРУНТУВАННЯ МЕТОДУ ГЕНЕРАЦІЇ СІТКИ ДЛЯ МОДЕЛЮВАННЯ ТЕЧІЇ У ВЕНТИЛЯТОРІ ГАЗОТУРБІННОГО ДВИГУНА

The study of flow in aircraft gas turbine engines is one of the main components for the creation of new compressors and fans with improved aerodynamic, acoustic, strength, overall weight, and other characteristics. In modern scientific research, the methods of the physical experiment are used at the final stages of flow studies in blade machines. a numerical experiment is used in the early stages. An obvious advantage of the numerical experiment is the ability to study many variants of constructions under different input and boundary conditions in a short period. However, a numerical experiment requires a preliminary selection and justification of its parameters and components. One such important component is the type of calculation mesh. The literature review shows that it is impossible to make an unambiguous conclusion about the choice of the type of method for generating the finite element mesh and the turbulence model. This work aims to compare a hybrid and structured mesh for flow modeling in an axial fan of a bypass engine with a high bypass ratio. Two impellers of a bypass engine with a high bypass ratio are selected as the object of study. Flow simulation in fans was studied at a rotor speed of 2202 rpm in the range of values of the gas-dynamic flow function at the inlet q (λ) = 0.4 ... 0.65. Based on the literature review, the system of Navier-Stokes equations was closed by the SST turbulent model. To select and substantiate the method of finite-element grid generation, a structured and hybrid mesh for two fan variants were constructed. According to the results of the calculations, the dependence of the pressure ratio of fan π on the gas-dynamic flow function at the inlet q (λ) was constructed. According to the results of the study, it can be stated that the discrepancy of the calculations for the impellers in the axial fan of a bypass engine with a high bypass ratio with structured and hybrid meshes will be up to 2 %. When choosing the method of mesh generation, the time of calculation is also an important factor. Studies have shown that the calculation with a structured mesh took place in less time by 50 ... 70% than when using a hybrid mesh for one variant of the geometry.

Current State and Prospects of Development of Gas-Insulated Power-Transmission Lines and Busbars at 110–1100 kV

Issues related to the development and technical operation of gas-insulated lines are considered. A comparison of the technical parameters of lines with different types of insulation is performed. The throughput of and losses in power-transmission lines of different types are identified; the specific electric capacity and technical losses in the gas-insulated lines are determined, and their safety and environmental friendliness are evaluated. The assessment of gas-insulated line construction variants and dependence of their real dimensions on the nominal voltage is carried out. Options for using different gases in gas-insulated lines are considered. The comparison of the intensity of magnetic fields of overhead, cable, and gas-insulated power lines showing the efficiency of the gas-insulated line application is performed.

The Effect of the Distribution Head Tilt and Diffuser Variants on the Evenness of Sowing Rye and Oat Seeds with a Pneumatic Seed Drill

Due to the sustainable development of agriculture machines with large working widths of 4–6 m or even 9–12 m are increasingly often used for agrotechnical operations. The sowing machinery whose working widths are much bigger than the width of the seed box is equipped with a pneumatic system for transporting seeds from the seed box to coulters. One of the structural elements that affect the sowing accuracy in such seed drills is the distribution head with a diffuser. This article is about research on the influence of the distribution head deviation from the vertical position and constructional variants of the diffuser (the number of diffusion rings and the configuration of their position in the diffuser pipe, which is the distance between them) on the accuracy of distribution of a stream of rye and oat seeds (a seed-and-air stream), which differ in physical characteristics. The main elements, i.e., the innovative stream distributor in the head and the diffusion rings were made using an original design and the rapid prototyping method. The research proved that a change of 0–10° in the angle of the distribution head deviation from the vertical position significantly affected the sowing quality of oat seeds only. The position (density) of the diffusion rings in the lower section of the diffuser (near the supply elbow) was the most effective for both oat and rye seeds, where the average values of the coefficient of variation were 5.31% and 4.62%, respectively. The research results can be used to redesign the construction of the diffuser of the seed drill distribution head so as to reduce the resistance of transport of the seed-and-air mixture in order to improve seed sowing evenness.

Theoretical and experimental research on the use of the blinking reflex for command and control of human body movement

The blink reflex is a behavioural motor response that is normally found in the process of seeing at newborns and human adults. As with the corneal reflex, the supraorbital branch electrical stimulation of the trigeminal nerve causes a facial nerve bilateral response, namely eyes blinking. Therefore, this sensitive process can also be a neurological control element for performing movements, related to the natural blinking process amplitude, speed and frequency. In the first part of the paper, a series of blinking process physiological aspects are analyzed, in order to identify the movements command and control components. In the second part of the paper, it is analyzed the devices constructive variants for evaluating the blinking process and the connecting possibility with separate sensory elements that can collect information from the visual system neuro-motor level. In the third part of the paper, there are mentioned some aspects related to the experimental installation design and the command and control mode for setting in motion a system using the coordinated ocular and neurosensory blinking mechanism. The final part presents the conclusions of this approach to the development of a system with the use of oculomotor and neurosensory stimuli.

Little cutie one piece

AbstractThis study investigates emerging usages in Chinese cyberspace of the numeral classifierméithat violate syntactic and semantic conventions of canonical grammar of modern Chinese. We treat these usages as constructional variants of the canonical classifier construction and show how they afford users of Weibo a device of social indexicality in the sense of Silverstein (1976,1985,2003) and Eckert (2000,2003,2008). We argue that the constructional variants facilitate the creation of a cute, chic, playful, humorous, and youthful online style and that its popularity draws on multiple indexical resources including contrast to canonical grammar, contemporary language contact with Japanese, influence of the cuteness culture and its commodification, and consumerism in the digital economy. This study contributes to research on the linguistic construction of identity and style, linguistic creativity in the new media and digital culture, and usage-based constructionist approaches to language.

Comparative Numerical Analysis on Vertical Wind Turbine Rotor Pattern of Bach and Benesh Type

In this work, 3D models in classic configuration of Bach and Benesh rotor type, as well as models with modified blade pattern geometry were analyzed from the air circulation point of view inside the rotor enclosure in order to identify the operating parameters differences according to rotor geometric modified configuration. Constructive design aspects are presented, as well as results obtained from the virtual model analysis in terms of circulation velocity and pressure values which enhance rotor operation related to torque and power coefficients. The rotors design pattern is made according to previous results obtained by different researchers who have performed numerical analysis on virtual models and tests on the experimental rotor models using the wind tunnel. The constructive solutions are describing two-bladed rotor models, in four new designed constructive variants and analyzed using ANSYS CFX. The air velocity specific values, static and total pressure recorded at the rotor blade level are highlighted, that influence the obtaining of rotor shaft torque and power. Also torque coefficient (CT) and power coefficient (CP) values according with specific values of tip speed ratio (TSR) are presented for each analyzed case. The analysis results show higher power coefficient values for analyzed Bach V2 and Benesh V2 rotor modified models compared to the classic Bach and Benesh models for 0.3 TSR of 0.11–012 CP, 0.4 TSR of 0.18 CP (Benesh V2 model) and 0.27 CP at 0.6 TSR (Bach V2). The resulted values confirm that Benesh V2 model offers higher CP up to 5% at TSR 0.3, 2% at TSR 0.6 and 3% at TSR 0.4 compared to the Benesh classical model. The Bach V2 model offers 4% higher CP compared to the classic Bach model at TSR 0.6. Based on these results it is intended the further analytical and experimental research in order to obtain optimal rotor pattern.

Optimization of guard rings construction and epitaxial film resistivity of power <i>n</i>-channel DMOS-transistor

Powerful n-channel DMOS-transistor with drain-source breakdown voltage Uds br value over 800 V and thresh-old voltage from 2 to 5 V was considered in this paper. One or more guard rings are formed on perimeter of such transistor for the breakdown voltage raising. The optimal guard rings construction was described and resistivity value of epitaxial film ρv was determined for obtaining required transistor Uds br value. The regression model was built, with the help of which the most optimal construction variants of guard rings of investigated transistor and resistivity value of epitaxial film, were selected. It was established that the five-dimensional polynomial of second order using as regression model allowed choosing the optimal topological spaces values in the guard rings area and ρv value which made it possible to obtain required Uds br values of the transistor. Experimental values of transistor drain-source breakdown voltage were 876 and 875 V, but calculated values (at identical parameters of definitional regression model) were 874 and 880 V, accordingly, that were errors of 0.23 % and 0.57 %, i. e. made model fits well with experimental data. It was established that ρv makes contribution to breakdown voltages values of the transistor that is more substantial than parameters of guard rings construction. This NDMOS-transistor was manufactured under production conditions of OJSC INTEGRAL” – “INTEGRAL” Holding Managing Company according to the technological route developed by the author. Such device is used in various electronic devices for energetics, in mobile phones, as part of high-voltage integrated circuits of AC/DC- and DC/DC-converters and high-voltage, high-stable LED-drivers.

Expander construction in VNC1

We give a combinatorial analysis (using edge expansion) of a variant of the iterative expander construction due to Reingold, Vadhan, and Wigderson [44], and show that this analysis can be formalized in the bounded arithmetic system VNC1 (corresponding to the “NC1 reasoning”). As a corollary, we prove the assumption made by Jeřábek [28] that a construction of certain bipartite expander graphs can be formalized in VNC1. This in turn implies that every proof in Gentzen's sequent calculus LK of a monotone sequent can be simulated in the monotone version of LK (MLK) with only polynomial blowup in proof size, strengthening the quasipolynomial simulation result of Atserias, Galesi, and Pudlák [9].

Numerical Analysis of Structural and Material Solutions for Selected Retaining Walls

Designing retaining structures depends on many factors, primarily the function of the retaining structure and soil conditions. It is not easy to choose the right retaining structure due to the great variety of their structural and material solutions. Preliminary numerical analyses in this case can be very useful. This article presents the results of numerical analyses of the behaviour of retaining structures and soil for various structural and material solutions as well as defined soil and water conditions. Six variants of retaining structures were analysed, in which the type of retaining walls, the materials used and the height of the walls were varied. The assessment was done basing on maps of stress and displacement of the retaining structure and soil. An additional factor in the selection of retaining structures are costs, durability and lead time. The finite element method allows the analysis of the behaviour of the structure - soil system. It enables comparison of various construction variants at the design stage and selection of the best solution in given soil and water conditions for the set selection criteria.

Диференційований підхід до використання кам'янистих садів у різних категоріях міських зелених насаджень та на Наддніпрянських схилах міста Києва

На основі літературних даних та результатів натурного обстеження досліджено сучасний стан кам'янистих садів Києва як перспективного напряму в садово-парковому будівництві. Проаналізовано екологічні особливості потенціальних місць розташування кам'янистих садів та наддніпрянських схилів за наявними даними. Оцінено особливості типів кам'янистих садів в урбанізованому середовищі. Запропоновано способи використання різних типів кам'янистих садів у міських умовах. Наведено рекомендації та варіанти побудови кам'янистих композицій у насадженнях різного функціонального призначення: кам'янистий сад на плоскому рельєфі, терасований кам'янистий сад, японський сад, рокарій, рокарій із папоротями, кам'янистий міксбордер, гравійний сад, мініатюрний рокарій, припіднята клумба, кам'яниста рабатка, альпінарій. Виконано порівняльний аналіз наявних типів кам'янистих садів, методів та підходів за їх використання в різних категоріях міських зелених насаджень, а також на наддніпрянських схилах. Встановлено, що в разі вмілого підбору деревних і трав'яних рослин перше квітування в кам'янистих садах можна спостерігати вже в квітні, а останнє – навіть у вересні-жовтні, тому вони є досить перспективними для покращення стану парків, скверів, вулиць, схилів Києва. Результати досліджень будуть використані для практичної діяльності студентів спеціальності 206 "Садово-паркове господарство" та наукових працівників.

Seismic Response of Mass Eccentric RC Framed Building

In the current study, six reinforced concrete framed buildings with various types of irregularities are designed in accordance with IS codes as test samples. Modal analysis, Response spectrum analysis, Push over analysis are performed on these structures and compare them with that of regular structures, shear forces and modal properties with the regular buildings that results variation in their behavior, which are considered the main causes of serious damage to the wrong plans of terraced buildings during earthquake. From this study, it finds that the asymmetric buildings shows that the maximum base shear for these different buildings are almost same. This is due to the base periods of all these buildings are almost uniform. The maximum results of the displacement of the roof for the symmetrical construction variant were found to be less differentiated from the two asymmetrical buildings for all cases studied here, which shows that the second asymmetric variant building is more acceptable than the first asymmetric variant building in all the cases. Code criterion for plan asymmetry building recommends that changing in the size of members of the structure or in the building but it has not mentioned that by giving eccentricity in opposite direction of the same structure where already eccentricity is available, it can reduce the plan asymmetry. To reduce eccentricity, variation in the stiffness dissemination can be very useful for such buildings.

The Application of Submerged Modules for Membrane Distillation.

This paper deals with the efficiency of capillary modules without an external housing, which were used as submerged modules in the membrane distillation process. The commercial hydrophobic capillary membranes fabricated for the microfiltration process were applied. Several constructional variants of submerged modules were discussed. The influence of membrane arrangement, packing density, capillary diameter and length on the module performance was determined. The effect of process conditions, i.e., velocity and temperature of the streams, on the permeate flux was also evaluated. The submerged modules were located in the feed tank or in the distillate tank. It was found that much higher values of the permeate flux were obtained when the membranes were immersed in the feed with the distillate flowing inside the capillary membranes. The efficiency of submerged modules was additionally compared with the conventional membrane distillation (MD) capillary modules and a similar performance of both constructions was achieved.

Description of the criterion of the effectiveness of the function of integrated economic analysis (evaluation) in functionally developed methods of strategic regulation of special purpose by enterprises

It is argued that, when characterizing the purpose of the analysis, it is important to clearly formulate its quality criteria, that is, the indicators by which it is possible to judge the degree and completeness of the purpose. Business policy requires the receipt of comprehensive information for the purposes of a comprehensive information management system with minimal cost of its formation and transformation. Based on this premise, a necessary logical element of a systematic approach in the process of creating a subsystem of analysis should be to determine such a criterion for the quality of its functioning, the magnitude of which could be judged on the advantage of one or another variant of function construction. If the general purpose of the administration subsystem is expressed by its objective function, then the quality criterion is the numerical expression of the objective function. It should be noted that the choice of quality criterion – an indicator that allows to judge the degree and completeness of the goal – is currently one of the most difficult and debatable problems. The formation of such a quality criterion, both for the whole production as a whole, and for various management systems and their parts, raises considerable methodological difficulties. This can be explained by the fact that designers of control systems still do not have a generally recognized quality criterion, to create control systems without which it is very difficult. This situation forces the developers of control systems in each case to put forward some of their quality criteria, not always satisfactory in content, which, in the end, often has a negative impact on the features of the generation of administration structures. It is substantiated that the only correct way to analyze the function of control systems of enterprises will be to find a quality criterion based on a common methodological approach. Proved a key requirement concerning the possibility of establishing functioning quality criterion when creating control systems in enterprises, economic analysis performed in full, rest.

Improved parallel construction of wavelet trees and rank/select structures

Existing parallel algorithms for wavelet tree construction have a work complexity of O(nlog⁡σ). This paper presents parallel algorithms for the problem with improved work complexity. Our first algorithm is based on parallel integer sorting and has either O(nlog⁡log⁡n⌈log⁡σ/log⁡nlog⁡log⁡n⌉) work and polylogarithmic depth, or O(n⌈log⁡σ/log⁡n⌉) work and sub-linear depth. We also describe another algorithm that has O(n⌈log⁡σ/log⁡n⌉) work and O(σ+log⁡n) depth. We then show how to use similar ideas to construct variants of wavelet trees (arbitrary-shaped binary trees and multiary trees) as well as wavelet matrices in parallel with lower work complexity than prior algorithms. Finally, we show that the rank and select structures on binary sequences and multiary sequences, which are stored on wavelet tree nodes, can be constructed in parallel with improved work bounds, matching those of the best existing sequential algorithms for constructing rank and select structures.

Особенности аудиторского задания по оценке уровня экономической безопасности бизнеса

In the article the order of documentary accompaniment of public accountant task is examined as evaluated by economic strength of business security both from the side of economic subject and public accountants. Th e authorial variant of construction of matrix of accordance of actual indexes is off ered fi nancially — to economic activity of economic subject to the threshold values of indicators of economic security of business.

СТРОИТЕЛЬСТВО ЕВРАЗИЙСКОГО ЭКОНОМИЧЕСКОГО СОЮЗА: ОЦЕНКА ЗАЩИЩЕННОСТИ НАЦИОНАЛЬНОЙ ЭКОНОМИКИ РОССИЙСКОЙ ФЕДЕРАЦИИ

The aim of the work is to assess the impact of the implementation of the integration project of the Eurasian economic Union (EAEU) with the participation of Russia, Kazakhstan, Belarus, Kyrgyzstan and Armenia on the protection of the national economy of the Russian Federation from external and internal threats. The author uses a methodological approach based on the consideration of various forms of ensuring the economic security of the state. An approach to assessing the level of economic security of the Russian Federation in various variants of the construction of the EAEU is proposed, which allows us to identify the priorities of cooperation or confrontation in the construction of the Union. The results of this work can be used to justify the strategy for implementing the integration project until 2025.

ВИКОРИСТАННЯ ПРИНЦИПУ СПІВВІДНЕСЕННЯ ДЛЯ ВИБОРУ ПРОГРАМИ ТЕХНІЧНОЇ ЕКСПЛУАТАЦІЇ КЕРОВАНИХ АВІАЦІЙНИХ ЗАСОБІВ УРАЖЕННЯ ПРИ ПЕРЕХОДІ НА ЕКСПЛУАТАЦІЮ ЗА ТЕХНІЧНИМ СТАНОМ

The article presents the current state of the available stock of guided air weapons and the problem of transition of guided air weapons to operation according to technical condition. The transfer of guided air weapons to operation according to technical condition involves increasing the role of measurement operations and control of their parameters and characteristics. This will determine the actual technical condition and make informed decisions about further operation. In general, the effective-ness of control a technical condition of aviation missiles significantly affects the readiness for use of aviation equipment and the combat capabilities of this equipment in performance of the tasks. The exciting control model and methods for selecting parameters of technical condition is universal in relation to the variants of construction of the technical maintenance program a guided air weapons allows to conduct research into these indicators. However, this program does not indicate the plural of variant that should be selected if the undetermined influence of different nature factors to carry out a set of maintenance and repair work for guided air weapons. The possibility of using the principle of correlation, when choosing the program of technical operation a guid-ed air weapons during the transition to operation according to technical condition. With the help of the correlation principle, an approach to the choice of the program of technical operation a guided air weapons can be developed in case of unknown infor-mation about the mechanisms of influence of various internal and external factors on the properties of the guided air weapons, their effect on the technical condition and features of the units of aviation guided missile that are not amenable to instrumental con-trol. To implement the control of guided air weapons with using a principle of correlation need to use the results of practical appli-cations of aviation guided missile, including other types of fire tests, sample tests using the physico-chemical analysis of powder and explosive charges.

A Quasi-Polynomial Approximation for the Restricted Assignment Problem

The Restricted Assignment problem is a prominent special case of Scheduling on Unrelated Parallel Machines. For the strongest known linear programming relaxation, the configuration LP, we improve the nonconstructive bound on its integrality gap from 1.9412 to 1.8334 and significantly simplify the proof. Then we give a constructive variant, yielding a 1.8334-approximation in quasi-polynomial time. This is the first quasi-polynomial algorithm for this problem improving on the long-standing approximation rate of 2.