bluuebunny/crossref_metadata_2025 huggingface dataset:
Monoversion techniques for increasing the fault tolerance of software systems for monitoring the parameters of technological processes
Authors: Losev V V , Kovalev I V , Saramud M V , Testoyedov N A , Tynchenko Ya A
Published: November 2020

The article discusses the current monoversion techniques in solving the problem of increasing the fault tolerance of software. The subject of research is the system of environmental monitoring of the technological process. Model examples demonstrate the algorithmization of the programming approaches used. As the first technique, a programming technique using Checkpoint is presented. The second technique is the programming technique using Checksums. Both techniques are designed to increase the fault tolerance of the developed specialized software systems.
Scheduling of the arrays of incomparable requests in the GRID systems
Authors: Saak Andrey , Kureichik Vladimir
Published: November 2020

The paper presents a method for classification of the parallel user’s requests in addition to the existing one represented by the resource rectangles. The proposed classification is considered as more fundamental as it serves to highlight the classes of comparative and incomparable resource rectangles. For the arrays of the incomparable requests, the method allows us to analyze the quality of polynomial algorithms for packing with the non-Euclidean heuristic measure that considers the form of the enclosing rectangle along with its area. Based on the test benchmarks for the optimal tiling in a non-empty square, we demonstrate the effectiveness of the proposed polynomial algorithms for dispatching of the incomparable user’s requests in the GRID systems.
Research on losses of technical preparedness of forage harvesters combines by level of seasonal service accumulation
Authors: Rogovskii I L , Hneniuk M V , Voinash S A , Galimov R R , Sokolova V A , Bespalova V V
Published: November 2020

The results of experimental studies are presented in article. It is established that minimal total costs for ensuring the technical preparedness of forage harvesters combines are possible to create using the optimal number of service activities. Formation of suboptimal number of service activities results in 27% and 18% losses (1 and 7 years of operational term of forage harvester). The article considers the graph of state of technical preparedness of forage harvester combines and develops an algorithm that calculates for each year of operation and for annual operating time the following indicators: average queue length; average number of pending requests; average number of service free channels; queue idle ratio; order utilization rate; idle ratio of servicing units; complete average losses due to idle queue requirements and less channel workload; time of waiting in line. The optimum number of channels was assumed to be the number with minimal total average cost of simple queuing requirements and no channel workload. The authors found out that the cost of ensuring of technical preparedness of forage harvesters depends on year of operation of harvesters and their annual loading. These costs reduce from 13.63% to 3.12%, for the accumulation of 150-180 hectares and from 6.5% to 3.98% (181-220 hectares). Therefore, with the increasing number of harvesters and their annual loading, the change in total costs is almost offset. The fluctuations in the total costs, depending on annual operating time and service assimilation of forage harvester, are less – 13.62% (150-180 ha) and 6.5% (221-330 ha).
Schematic and algorithmic methods of elimination influence of interference on accuracy of intellectual interfaces of the technological process
Authors: Jumaev O A , Nazarov J T , Sayfulin R R , Ismoilov M T , Mahmudov G B
Published: November 2020

The article discusses the main requirements for an intelligent measuring channel in the design of automated monitoring and control systems. Methods for estimating errors and noise are analyzed, constituent groups are classified, and some methods for calculating the noise of measuring instruments and measuring modules of automatic control systems are given.
Research of diagnostic of combine harvesters at levels of hierarchical structure of systems and units of hydraulic system
Authors: Rogovskii I L , Liubarets B S , Voinash S A , Sokolova V A , Luchinovich A A , Kalimullin M N
Published: November 2020

The problem of diagnosing by external signs of the technical conditions of hydraulic systems of combine harvesters was formulated by the authors in the following way: we need to build a decisive rule that allows us to determine the presence of individual failures in the object from the observed external sign. As an example, we made a research on four general processes, often performed by the main hydraulic system of the harvester: raising the harvesting part, lowering the harvesting part, turning the unloading auger from the transport position to the working one, and turning the unloading auger from the working to the transport one. Failures characterize the technical condition of the harvester subsystems, which in turn consist of many different aggregates and parts. To restore working capacity, it is necessary to demonstrated failures of elements at the level of the hierarchical structure of the harvest, where this restoration is most effective for the conditions of a particular enterprise. Thus, for developing universal diagnostic tools, it is more efficient to identify failures at the lower level with a certain margin of diagnosis depth. The results of research made it possible to implement an intelligent operator support system for the collection and analysis of information about the technical condition of hydraulic systems of combine harvesters and imitate the work of a highly qualified specialist in the field of technical diagnostics.
The epsilon expansion near absolute zero
Authors: Udodov V N
Published: November 2020

Epsilon expansion is an important part of the renormalization group approach; it allows substantiating the scaling paradigm and is used in the modern theory of critical phenomena. It is shown that at a critical temperature equal to zero, the expression for the critical heat capacity exponent already in the first order in epsilon d − = 4 – (d – is the dimension of space) changes its form. This, however, does not indicate a violation of the scaling approach, although the classical Essam-Fisher equation also changes, as does the Rushbrook inequality. The generalized Essam-Fisher interpolation equality and the generalized Rushbrook inequality are given, which are valid for any value of the critical temperature, in particular, for the critical temperature equal to zero. The generalized relations are consistent with the renormalization-group approach, - expansion and scaling paradigm. The fluctuations are considered to be classical (thermodynamic), the conditions are determined when this takes place.
Influence of non-uniformity of fuel supply parameters on diesel engine performance
Authors: Apazhev A K , Shekikhachev Y A , Batyrov V I , Shekikhacheva L Z
Published: November 2020

The state of the fuel equipment as a whole can be judged by two generalized parameters characterizing the performance of a diesel engine - its power and specific fuel consumption. The state of the fuel equipment is characterized by the following parameters: injection pressure and the quality of fuel atomization by nozzles, the capacity of the booster pump, the throughput of filter elements for coarse and fine fuel cleaning, the state of the bypass valve, wear of the plunger pairs and discharge valves, the speed of the camshaft of the fuel pump, uneven delivery fuel by pump elements, fuel consumption, advance angle of fuel supply to engine cylinders. During operation, these parameters change due to the deterioration of the state of the elements of the fuel equipment. The initial state of the parameters of the fuel equipment is restored by making the necessary adjustments and replacing the components unsuitable for further operation. Signs of unsatisfactory operation of the fuel equipment can be: difficult start of the diesel engine, unstable operation, smoke of the exhaust gases, a decrease in power and an increase in specific fuel consumption. Improvement of diesel fuel supply systems should be aimed, first of all, at increasing power and fuel efficiency, as well as decreasing smoke and toxicity of exhaust gases, which can be achieved by: increasing the maximum injection pressure; optimization of injection characteristics and reduction of injection duration; correction of the cyclic fuel supply in accordance with the engine operating mode and external factors. With this in mind, this article presents the results of a study of the unevenness of the fuel supply and its effect on the power and economic performance of the diesel engine.
Modeling frequency integrating unfolding converter with a semiconductor strain gauge bridge taking into account temperature effect
Authors: Volkov Vadim S , Konkina Maria S
Published: November 2020

The article considers development of an algorithm and construction of a simulation model of frequency integrating unfolding converter characteristics for a bridge circuit with semiconductor strain gauges, using the MathCAD software as simulation environment. Construction of a simulation model gives the possibility of joint application of bridge circuits with semiconductor strain gauges and frequency integrating unfolding converters in the development of sensitive elements of sensors for mechanical quantities that able to function at high temperatures. An algorithm for determining components of the output signal frequency error is proposed, taking into account variation in parameters of strain gauges and the effect of high temperature, which will allow revealing influence of the error components on the output signal frequency. As a result, the above mentioned can be used in the development of additional methods and means for temperature compensation, taking into account features of semiconductor strain gauges, and to increase objectivity in the analysis of calculation results applied to converters of mechanical values into frequency.
Constructive method of increasing the durability of cultivator blades recovered by surface
Authors: Rogovskii I L , Titova L L , Voinash S A , Maksimovich K Yu , Galimov R R , Sokolova V A , Parfenopulo G K , Taraban M S
Published: November 2020

The technical condition of parts is determined, on the one hand, by design parameters, and on the other, by mechanical properties, which are determined by control methods, including holographic ones. The properties of the working surfaces of parts made of various materials differ in comparatively small values of the dispersion of indicators. They correspond to the magnitudes and types of load, micro straining, load duration and can be presented in a rather narrow dispersion interval. The value of the distribution parameters of these quantities must be taken into account, first of all, when choosing a material. It is determined by the reliability conditions that the onset of the permissible load limit is achieved by proportional loading of the entire structure and is achieved with a micro deformation value for cultivator blades of 2.1-3.2μm. The limiting value of the micro deformation parameter is a function of a given tolerance for permanent deformation of the structure and is difficult to determine by conventional methods. In accordance with the developed methodology for the study of parts made of different materials, for example: graycastiron, aluminum, polymers (polyethylene, polyamide), carbon fiber, as well as a reinforced metal polymer, at the same time, computer holograms are recorded in each case. The studies used the entire range of recorded loads.
Morphological methods of searching for new engineering solutions and their use in Industry 4.0
Authors: Rakov Dmitry
Published: November 2020

The Innovation techniques as part Industry 4.0 is critical for competitive and economic for new systems and products and thus has been widely debated. This research suggests a morphological approach to innovations development as well as to tools for creating promising engineering solutions of conceptual design stage. The article presents the history of the development of morphological methods. These methods are as techniques for solving multidimensional, multicriterial and non-quantifiable problems under uncertainty conditions. The approach can be a successful analytical tool for development schematic, conceptual and preliminary design, decision making, design development, production management etc. The method is a conceptual tool that can be used to generate solutions space, systematization of knowledge, enhancement application opportunities and achieve the synergistic effects. Analysis of emerging technologies and systems and their potential opportunities with technique provide correct guidelines to supply the reasonable decisions with into account future risks.
The use of conceptual modeling to ensure the reproduction efficiency of fixed foundry assets
Authors: Kukartsev V V , Markevich E A , Rudyaga E V , Shalaeva D S , Leonteva A A , Kurashkin S O
Published: November 2020

The reliable operation of an induction melting furnace directly depends on the quality of its lining. The final operation in the manufacture of the lining is to carry out the developed sintering regime. The sintering quality is influenced by many factors, for example, the quality of the material used for manufacturing, compliance with the manufacturing process of the lining itself, and others. Therefore, it is necessary to monitor compliance with the sintering mode of the lining. The easiest option is a sintering schedule. Based on this, the article considers an application that builds a graph of temperature changes with the number of points specified by the user. When plotting the temperature changes in the melting furnace, the program has the opportunity to enter the data that were recorded earlier in order to see how the system worked. The program allows specialists to use it in the work process to predict the operation of the melting furnace on the basis of which it is possible to make adjustments to the work process in order to avoid emergency situations for people to work. In addition, it makes it possible to ensure the efficiency of reproduction of the main foundry production assets.
Monitoring hardeners of low toxic urea-formaldehyde resins
Authors: Kantieva E V , Ponomarenko L V , Starodubov A S
Published: November 2020

According to European standards, the most stringent standards for the content of formaldehyde belong to the emission class E 0.5. The hardening of resins with different formaldehyde content is different and it has not yet been sufficiently studied. The production of the woodworking industry face difficulty in the use of low toxic urea-formaldehyde resins. On the one hand, life and standards require environmentally friendly products, on the other hand, the use of low-toxic resins leads to a large percentage of defects in the production process, reduced productivity and deterioration of the strength properties of the finished product. The polycondensation reaction of low-toxic resins using a classical hardener-ammonium chloride is slower in comparison with resins with a high content of formaldehyde, that is, performance is reduced. The paper examines the influence of various hardeners on the physical and chemical properties of the glue (gelatinization time, viability, pH of liquid and cured adhesives). All the studied preparations can be used as a hardener of low-toxic urea-formaldehyde resin, but its content should be adjusted taking into account the physical and chemical parameters of the initial state of the resins and production conditions.
Development of a system for control of synthesis of methyl tertiary butyl ether
Authors: Muravyova E A
Published: November 2020

Methyl tertiary butyl ether is an oxygen-containing octane-increasing component used to increase the octane number of gasoline. The use of MTBE is very important in the modern world, since it improves not only the parameters of detonation resistance, but also reduces the content of carbon monoxide and hydrocarbons in the exhaust gases, which positively affects the environment. The article describes the technology of the synthesis of methyl tertiary butyl ether, gives a functional diagram of the process, the parameters involved in the production process, their control limits, which correspond to the manufacturer’s regulations, a mnemonic diagram, the dependence of the parameters on each other in the form of formulas, in addition, the process of creating a control program and developing a process control system is shown. The main objectives of the development of a methyl tertiary butyl ether synthesis process control system are the control and regulation of process parameters, as well as the search for the optimal use of resources and materials to increase the yield of finished products. The SCADA system was developed based on the actual limits of parameter control during the technological process. The expediency of using a SCADA-system is substantiated.
Tacking with curvilinear knives for grinding fibrous plant polymers
Authors: Marchenko R A , Shurkina V I , Yarovoy S V
Published: November 2020

The method for calculating the main technological parameters of a set with a curved shape of knives is presented. The aim of the work is to design a disk set with circumferential knives and to determine dependencies that allow predicting the technical and technological parameters of this set, the quality of the resulting semi-finished product during grinding, increasing the productivity of the grinding plant and reducing energy consumption during grinding. For the first time, a numerical method has been developed for calculating the second cutting length (Ls) of a knife set with a curved shape of knives, taking into account the main geometric parameters of the set. The geometric construction of the knife set of grinding machines allows to purposefully predict its use for various modes of the grinding process in the production of certain types of finished products. The research results can be used in the design of new types of headsets, their manufacture and operation.
Algorithm of ecological solutions in the smart city concept
Authors: Sergeev S M , Starodubtsev Y I , Kravets O Ja , Jawasreh H M
Published: November 2020

Solving the ecological problems of big cities is made difficult by the fact that their activities are built on the concentration of many kinds of resources. The economic foundation for their prosperity is made up of scientific, manufacturing, and cultural opportunities. At the same time, negative externalities occur, and natural and technological restrictions come into effect. The lessons of the COVID-19 pandemic require seeking out new methods of managing metropolitan areas. Global cities are unique in their constant influx of people - tourists, expats, students, and so on. This paper presents a way to solve the problems relating to regulating the inflow of visitors. A dynamic model of the spread of the infection is put together, the arguments for which are the restrictive and quarantine measures. At the same time, the problem of finding an economically sound balance between ecological externalities and the capacity of limited resources is solved. When solving these two problems using computer simulation, it becomes possible to use information flows of smart city systems, while the results of the calculations provide the basis for adopting the optimal set of administrative and technical solutions.
The use of 3 dB multi loop directional coupler with reduced dimensions in Marine communication systems
Authors: Hung L Q , Nhung D T
Published: November 2020

This article describes the process of developing a model of a multi loop directional coupler for marine applications by replacing conventional segments with artificial transmission lines. As a result, a coupler with an area of 2455 mm2 (at a frequency of 0.9 GHz) was obtained, which is 75.15% less than when the coupler is implemented on quarter-wave segments. The relevance of this work lies in the development of compact devices with easily reproducible geometry through the use of artificial transmission lines.
Effect of cavitational conditioning of water on stability of coal-water slurry
Authors: Stebeleva O P , Kashkina L V , Rubleva T V , Dobrosmyslov S S , Vshivkova O A
Published: November 2020

Coal-water slurry (CWS) is the basis of modern alternative fuel - coal-water fuel (CWF). To produce stable coal-water slurry, i.e. coagulation and separation is an important technological problem. The paper studies CWS the disperse part of which is fine brown Kansk-Achinsk coal, the dispersive part is distilled water. Effect of cavitational conditioning on CWS stability has been studied. The efficiency was for the first time studied by magnetic resonance tomography (MRT). In the experiment spin-lattice relaxation time profiles T1 were recorded along the central vertical axis of the samples. T1 dynamics correlates well with the local density of CWS solid phase. MRT data was sequentially interpreted with rheological characteristics of CWS. Feasibility of applying MRT method to find out time and space evolution of CWS has been estimated. The MRT methods has been shown to be efficient in resolution of technological problems to improve consumer properties of the coal-water fuel.
Optimization of costs for production and transportation of heat carrier in the district heating system
Authors: Vologdin S V , Korepanov A V
Published: November 2020

The article presents a problem statement and an algorithm for optimizing the parameters of the heat network and the power of heat sources (boilers, thermal power plants). Solving the optimization problem allows you to minimize the cost of production and transportation of the heat carrier, determine the optimal operating modes of pumping stations, as well as the performance of heat sources for a multi- circuit heat network. The proposed algorithm also includes calculation of the cost of heat energy production from various heat sources. The results of calculations of test problems on various model schemes of heat supply with an arbitrary number of consumers, heat sources, and pressure regulators are presented. Optimal regulation allowed to reduce total costs in the test calculation to 10%. The proposed method for solving the extremal problem showed good convergence of the iterative process. When calculating networks without pressure regulators, the method quickly converges. In the presence of pressure regulators, the convergence of the iterative process worsens, since the target function is nonlinear in this case. The research results can be recommended for making management decisions to improve the quality of functioning of district heating systems.
Combined acoustic-convective drying of plant products
Authors: Khmelev V N , Shalunov A V , Nesterov V A , Terentyev S A , Tertishnikov P P , Bochenkov A S
Published: November 2020

The paper presents the design of drying plants that combine convective drying with ultrasonic exposure. To create ultrasonic vibrations, ultrasonic emitters in the form of bending-vibrating discs with a diameter of 205 mm and 104 mm were used. Peas and vegetables were the objects of drying. As a result of the experiments, it was found. Drying with the help of ultrasonic action together with the thermal one proceeds no less than in 45% faster in comparison with the drying without ultrasonic action. During the drying of peas using the acoustic field, the drying time was reduced by 210 minutes (45%). The use of powerful ultrasonic action in a non-contact mode on dried carrot samples made it possible to reduce the drying time by 300 minutes, which is 47%. The acoustic method of drying allowed to reduce the drying time of potatoes by 300 minutes (45%).
Influence of measurement error for the results of defection of parts hole-type
Authors: Leonov O A , Shkaruba N Zh
Published: November 2020

Technological processes of repair production for a number of objective and subjective reasons do not provide the required reliability of equipment after repair. It has been shown that the most important process for incoming inspection of worn parts is fault detection. It is shown that the control process during flaw detection occurs not at the edges of the scattering zone, as it happens in mechanical engineering, but in the center. Features of formation of control errors of the 1st and 2nd kind during flaw detection of hole-type parts in repair production are considered. A new approach is proposed to assess the influence of measuring instrument error on the results of flaw detection of hole-type parts. this approach consists in developing a calculation method and plotting the dependences of calibration parameters for flaw detection of parts. Based on the proposed approach, the distribution of sorting parameters for hole-type parts by groups during defect detection is determined. The results were analyzed.
Assessment of the level of environmental innovation in industrial production and information and communication sphere
Authors: Gibadullin A A , Romanova Ju A , Morkovkin D E , Pirakov R M
Published: November 2020

The article analyzes environmental innovations in industrial production and information and communication activities. Because of the analysis of the indicators, it was revealed that technological innovations in all considered areas of activity do not exceed 10%, and environmental innovations in industrial production reach 16%, in the information and communication sphere, they do not exceed 3-4%. The study found that such a situation indicates that not all enterprises have adopted a sustainable development policy and ensure the preservation of the environment for future generations. The analyzed indicators for the control of environmental pollution by various enterprises that use the tools of the information and communication sector in this matter are carried out only on a part of enterprises. At the end of the study, measures were proposed to enhance innovation in the field of ecology in all spheres of activity and industries.
The enhanced plate heat exchanger for systems of housing and communal services
Authors: Savvin N Yu , Kushchev L A , Feoktistov A Yu , Roshchubkin P V
Published: November 2020

The problem of intensification of thermal processes and the process of heat exchange in a plate heat exchanger of the HHN02 type is considered. A comparison is made of two types of heat exchangers - shell-and-tube and plate. The formulas for calculating heat transfer and heat transfer coefficients are presented. The analysis of theoretical studies on the intensification of heat transfer in a plate heat exchanger with a corrugated surface of the plates is carried out. A full-scale experiment was carried out on a specially designed semi-industrial stand “Independent heating system of a residential building”. It has been found that the use of a corrugated surface is capable of providing a high value of the heat transfer coefficient. It has thus confirmed the advantages of the plate heat exchanger in comparison with the shell-and-tube.
Intensification of heat removal in diabatic columns
Authors: Voinov N A , Deryagina N V , Zemtsov D A , Bogatkova A V , Zhukova O P
Published: November 2020

Diabatic units having heat exchanger tubes functioning as dephlegmators on trays, which allow to reduce the cost of the process, are considered. It is shown that the most efficient approach is to arrange heat removal with the film flow of the heat carrier in the diabatic column dephlegmator. Heat transfer intensification in a gravitationally flowing film, as well as to in an upward and downward parallel flow during the heating and boiling of the heat carrier was analyzed. Dependences for determining the value of the heat transfer factor are presented.
Problems with boundary conditions for one component solution in the ODE system
Authors: Dzhabrailov A L , Israilov S V
Published: November 2020

The article investigates a new type of boundary value problems with boundary conditions for only one component of the solution of a system of ordinary differential equations that cannot be investigated for the existence and uniqueness of a solution by traditional methods. In this work, to study this type of non-standard problems with boundary conditions, the method of linear mappings was used. The use of this method for this kind of non-standard problems is justified in the monograph of one of the authors of this article. Three theorems are proved: two on the existence of a solution and one on the uniqueness of a solution. The proof of these theorems follows from M.A. Krasnoselsky’s principle. since the right-hand sides of the system consist of the sum of two operators, the first of them is a contraction operator, and the second is a completely continuous operator.
Low gain antenna beam forming using metamaterial
Authors: Romanov A G , Testoyedov N A , Tutyarov N A , Sedelnikov Yu E
Published: November 2020

The work considers the possibility of using metamaterials to design of low-gain antennas with improved parameters of antenna pattern. It is shown that additional elements of the antenna, made of metamaterial, can be considered as antenna array of parasitic emitters, forming antenna pattern of the required shape. It is shown that the use of metamaterial inserts allows to optimize irradiators for reflector and lens antennas.
Investigation of the possibilities of increasing the resolution of lidars in the infrared wavelength range for monitoring methane in the atmosphere
Authors: Grigorievsky V , Sadovnikov V , Elbakidze A , Tezadov Ya
Published: November 2020

The paper deals with the resolution of an optical lidar for measuring the background concentration of methane in the atmosphere both on surface horizontal paths with reflection of an optical signal from natural objects and on vertical paths, when an optical signal is reflected from cloud layers with extrapolation to low space orbits. It was shown using simulations that in the case of measurements from a low space orbit, the signal accumulation time can be reduced to 1 second or less due to the large signal attenuation at the center of the absorption line in the atmospheric air column. For a signal accumulation time of 1 s, the horizontal resolution along the horizontal coordinate will be ∼8 km at a satellite orbital velocity of ∼8 km / s. The vertical resolution for measurements from space orbit can be ∼ 1 km if the accuracy of measuring the absorption line broadening is ∼0.006 nm (10%). On the horizontal paths, the experimental results are in good agreement with the simulation results. Broadening the emission line of the lidar transmitter by a factor of ∼3 makes it possible to increase the radiated power at the considered wavelength ∼ 1653 nm, improve the energy potential of the device, and bring the horizontal resolution to 5-10 meters on the speed of lidar beam, corresponding to the speed of the helicopter.
Substrate-dependent control of the chiral orientation of mesenchymal stem cells: image-based quantitative profiling
Authors: Das Ankita , Adhikary Shreya , Chowdhury Amit Roy , Barui Ananya
Published: November 2020

Stem-cell (SC) chirality or left-right (LR) asymmetry is an essential attribute, observed during tissue regeneration. The ability to control the LR orientation of cells by biophysical manipulation is a promising approach for recapitulating their inherent function. Despite remarkable progress in tissue engineering, the development of LR chirality in SCs has been largely unexplored. Here, we demonstrate the role of substrate stiffness on the LR asymmetry of cultured mesenchymal stem cells (MSCs). We found that MSCs acquired higher asymmetricity when cultured on stiffer PCL/collagen matrices. To confirm cellular asymmetry, different parameters such as the aspect ratio, orientation angle and intensity of polarized proteins (Par) were investigated. The results showed a significant (p < 0.01) difference in the average orientation angle, the cellular aspect ratio, and the expression of actin and Par proteins in MSCs cultured on matrices with different stiffnesses. Furthermore, a Gaussian support-vector machine was applied to classify cells cultured on both (2% and 10% PCL/Collagen) matrices, with a resulting accuracy of 96.2%. To the best of our knowledge, this study is the first that interrelates and quantifies MSC asymmetricity with matrix properties using a simple 2D model.
Tripartite genuinely entangled states from entanglement-breaking subspaces
Authors: Sun Yize , Chen Lin , Zhao Li-Jun
Published: November 2020

The determination of genuine entanglement is a central problem in quantum information processing. We investigate the tripartite state as the tensor product of two bipartite entangled states by merging two systems. We show that the tripartite state is a genuinely entangled (GE) state when the range of both bipartite states are entanglement-breaking (EB) subspaces. We further investigate the tripartite state when one of the two bipartite states has rank two. Our results provide the latest progress on a conjecture proposed in the paper [Yi Shen et al 2020 J. Phys. A
53 125302]. We apply our results to construct multipartite states whose bipartite reduced density operators have additive entanglement of formation (EOF). Further, such states are distillable across every bipartition under local operations and classical communications.
Synthesis of a New Type of CMK-3-Pt with the In-situ Growth Method and Its Characterization
Authors: Yang Hongyi
Published: November 2020

With the growing consumption of fossil energy, fuel cells are now playing an increasingly important role in production and life. However, the battery electrode materials synthesized by traditional methods often have defects such as Pt particle agglomeration and shedding in use which can result in unsatisfactory performance of electrode materials and reduced electrical energy transfer efficiency and electrocatalytic efficiency, thereby leading to lower fuel cell efficiency. In this research, a new method is proposed for synthetizing the most important component of fuel cells—electrode materials, that is, the precursors of C and Pt are simultaneously added to the CMK-3-Pt produced with in-situ grow and one-step synthesis in the SBA-15 template. The elements and micro-areas were characterized by XRD, SEM, TEM and other test methods, and the CHI700E electrochemical workstation was used to test the electrocatalytic activity and electrocatalytic stability. The experimental results show that the Pt particles of electrode materials synthesized by the new method have the characteristics of smaller particle size (4∼6 nm), better dispersion, and less falling off. Besides, these materials have a larger pore volume (0.66 cm3/g), a higher active surface area (803 m2/g, ECSA: 452 cm2/mg), and more excellent electrocatalytic performance (the ratio of peak forward and reverse current: CH3OH catalyst is 1.95, and CH3CH2OH catalyst is 1.38) and better electrocatalytic stability (82.6%). To sum up, electrode materials synthesized once by the in-situ growth method can achieve better performance of the mesoporous electrode materials than those with the traditional synthesis method.
Research on Quality Risk Assessment of EPC Projects for Transmission and Distribution Engineering Based on Design Enterprises
Authors: Zhao Zhong Ze , Meng Qichen , Pang Nansheng
Published: November 2020

Among EPC general contractors, design companies often dominate by virtue of their design advantages. However, due to the complex risks of power transmission and transformation projects throughout their life cycle, quality management is the weak point of the EPC general contractor with design as the leader, and the problems caused by quality risks are directly related to the contractor’s Economic interests and credibility. Therefore, this paper will analyze the potential quality risks in the whole process of the project, establish a risk identification list, and use the fuzzy comprehensive evaluation method to evaluate the quality risk of the EPC project of the power transmission and transformation project led by the design enterprise based on the principle of maximum membership degree.
Image Dehazing Algorithm Based On Improved Guided Filtering
Authors: Lin Jin Chen , Yang Junjie , Yu Ting , Geng Chuanping
Published: November 2020

Aiming at the problem that the image defogging algorithm based on the dark channel prior will cause the edge halo effect in the restored image, an image defogging algorithm based on improved guided filtering is proposed. First, the calculation method of atmospheric light value based on the quadtree algorithm is adopted to obtain a more accurate atmospheric light value; then, the edge weight factor based on the Canny operator is added to the guided filtering algorithm to solve the local halo effect; finally, the image is restored based on the atmospheric physical model. Experiments show that this algorithm is better than other algorithms in subjective visual effects, and the image edge defogging is more natural; the comparison of objective performance indicators shows that the improved defogging algorithm has higher image quality and better image restoration.
Similarity Analysis-Based Diagnosis Method for Open-Circuit Faults of Inverters in PMSM Drive Systems
Authors: Chen Tao , Pan Yuedou
Published: November 2020

A fast, real-time and similarity analysis-based diagnosis method for open-circuit faults in three-phase voltage-source inverters is proposed. The proposed method is based on the mixed logical dynamic (MLD) model of the PMSM drive system to simulate three-phase currents under different faulty conditions, and the Pearson correlation coefficients (PCCs) are used to measure the similarity between the simulated fault types and the actual one, then the fault detection and isolation can be achieved according to the characteristics of PCCs under different faulty conditions. The proposed method only needs to use the current sensors existing in the closed-loop system to measure the currents for fault diagnosis, and can detect the fault within one current fundamental wave period. Simulation results verify the effectiveness of the proposed method.
Research on the SCVM Flux Error MRAS Observer of Asynchronous Motor Based on SMC
Authors: Zhu Wenbai , Deng Xin , Hu Dan
Published: November 2020

Aiming at the sensorless control system of asynchronous motor, a MRAS observer method for asynchronous motor SCVM flux error based on sliding mode control (SMC) is proposed. This method uses the SCVM voltage model flux error to form a MRAS observer to identify the speed and estimate the rotor flux, and a sliding mode speed controller is designed to replace the traditional PI speed controller. The algorithm can reduce the overshoot of the dynamic response of the system speed at medium and high speeds, shorten the time to enter the steady state value, and enhance the robustness of the system. Simulation results show the effectiveness of the algorithm.
Transient Response Test System Based on FPGA
Authors: Xiao Zhang , Fang Zhao , Sang Deyi , Zong Fuqiang
Published: November 2020

A test system based on FPGA for second-order system transient response has been designed. The system uses the XC3S400 as the control core, and the VHDL hardware description language has been used to program FPGA to achieve the function of measuring the transient response parameters of the second-order system. The transient response waveform and the measurement result are displayed through VGA. The test results are within the error range, the overall index is good, and the curve storage and playback function are also implemented.
Study on the Optimization of Steam Turbine Exhaust Channel Based on Adding Diversion Device
Authors: Qiao Chunzhen , Zhu Chengfeng , Su Lanqing , Wan Kuifang
Published: November 2020

This paper studies the problems of high exhaust pressure and low economic efficiency caused by the uneven flow field at the exit of the steam turbine exhaust channel. This paper uses CFD simulation software to carry out numerical simulation on the steam turbine exhaust passage, and obtains a layout of the guide device that can greatly improve the uniformity of the flow field at the exit of the exhaust passage. This optimization scheme was applied to a domestic 600MW steam turbine unit for performance comparison and economic analysis before and after optimization. The results show that the average pressure of the condenser drops by about 0.704kPa. The coal consumption for power generation drops by about 0.525g/kWh. The annual standard coal saving is about 1729t. Therefore, installing a suitable diversion device can improve the operating efficiency of the unit, and has better economical efficiency and energy saving and emission reduction effects.
Research on Optimizing Method of High Speed Railway Passing Capacity Utilization
Authors: Naranbaatar S. , Jiang Jian
Published: November 2020

The mode of transportation organization adopted by China’s high-speed railways is the “transportation organization for trains running at different speeds”. The advantage of this model is that it facilitates the travel of travelers, reduces the time and energy wastage caused by the transfer, and improves the travel experience of passengers. However, this mode has many disadvantages and may not necessarily meet the passenger travel demand. Therefore, this paper focuses on how to use the idea of compressed operation diagrams to create an optimized model under the mode of “transport organizations with different speed-class trains collinearly operating”. Stop plan provides a reference.
Research on the Determination of Reasonable Cost Range of Power Grid Production Technological Transformation Project
Authors: Zhao Xin , Ni Tongyun , Miao Xujuan , Guo Lijuan
Published: November 2020

This paper proposed a method to determine the reasonable cost interval of power grid production technological transformation project based on Kernel Density Estimation (KDE). The general idea of the study of reasonable cost interval is to select sample data, determine the sample estimation method, remove the outlier data, and finally calculate the reasonable unit cost interval of power grid. The general idea of the study of reasonable cost interval is to select sample data, determine the sample estimation method, remove the outlier data, and finally calculate the reasonable unit cost interval of power grid technical transformation project. Taking the actual data of the disconnector replacement project as an example, this paper made statistics of the reasonable cost range of the power grid production technological transformation project, which provides a new idea and method for the reasonable determination of the cost range in the case of large amount of data.
Research on Yaw Deviation of Wind Turbine Based on Dynamic Time Warping
Authors: Xu Xinda , Hong Bin , Wei Yan , Wang Hao , Yin Xianlong , Wang Hao
Published: November 2020

The yaw deviation is common in the process of wind turbine generation. Excessive wind deviation will cause a series of problems, such as the reduction of wind turbine generating efficiency, the wear of main shaft, gearbox failure. In this paper, a wind deviation detection algorithm based on dynamic time warping is proposed by using data in supervisory control and data acquisition (SCADA) of wind turbine. Through dynamic time warping (DTW), the wind speed is divided into three sections: ascending, descending and stationary. Then the wind speed is divided into three sections, and the wind deviation is obtained by fitting the function of wind angle and power. Compared with the traditional algorithm, the wind deviation detection algorithm proposed in this paper is more stable and accurate.
Research on Benefit Analysis of CCHP-WSHP System in Vehicle to Building
Authors: Zhao Xin , Mu Hailin , Li Nan , Xue Zhaoquan , Yang Xiyue
Published: November 2020

This paper proposes a combined cooling, heating and power (CCHP) system, which comprehensively uses water source heat pump (WSHP) system and vehicle to build (V2B) mode. The CCHP-WSHP-V2B could efficiently solve the problems when a CCHP or a WSHP operates independently. And it can acquire better system performance. In this mode, the CCHP system can flexibly exchange electricity with electric buses and coordinate electricity demand. The water source heat pump can supplement the cooling load and heating load of the system. Furthermore, a case study based on a hotel building is established and studied to verify the effectiveness of the model. The results of the case study show that the primary energy saving ratio, carbon dioxide emission reduction ratio, and annual total cost saving ratio comparing with the separate production system are 36.09%, 43.06%, and 25.47%, respectively.
Optimal Design and Test Study on Sound Insulation Property of Exterior Wall Enclosure of Prefabricated Substation
Authors: Li Xiang , Mo Juan , Cai Hongjun , Liu Shouliang , Zhu Zhanwei , Jiang Zaixing , Ma Yuchao
Published: November 2020

In this paper, based on the fabricated wall panel used in original modular indoor substation, the optimal design of sound insulation property is conducted according to the relevant theoretical basis of sound insulation properties of wall panels, and the reverberation room method is used to test and study original and new wall panels. The study shows that the sound insulation of the sandwich panel after optimization has been greatly improved in both medium, low and high frequency areas, with obvious optimal design effect, and also there are significant engineering application value and social benefits in the noise control of substation.
High-precision Flux Linkage Observation of Induction Motor based on Spectral Decomposition Theory
Authors: Pan Yuedou , Zhang Weifeng
Published: November 2020

In the vector control system of induction motor, there is a delay in the switching device, which causes current distortion and motor performance degradation. Especially for high-power induction motors, the switching frequency of the inverter system is low, and the time delay effect is obvious. The mathematical model of magnetic flux observation of induction motors generally ignores the delay of the switching device. Therefore, the mathematical model is not accurate and the accuracy of the magnetic flux observation is not high. To address this problem, the mathematical model of the induction motor with delay is established, and the spectral decomposition flux linkage observer is designed to observe the rotor flux linkage in this paper. The designed spectral decomposition magnetic flux observer has the advantages of high magnetic flux observation accuracy. Simulation results prove the feasibility and effectiveness of the designed spectral decomposition flux observer.
Hydraulic Pitch Control Delay Estimation and Compensation Method for Large Wind Turbine
Authors: Wang Xiangming , Pan Jiahui
Published: November 2020

At present, using hydraulic pitch control for large wind turbines is becoming a trend. However, there will be a delay in the process of hydraulic pitch control, which will affect the stability of the system. In view of the influence caused by the delay in the wind turbine system, this paper designs a delay estimator and compensator using the Assumed Mode method, which linearizes the perturbation generated in the process of hydraulic pitch control and calculates the parameters with the method of function fitting, so as to overcome the adverse effect caused by the delay of hydraulic pitch control. At the same time, a pitch control system based on fuzzy control is designed to form a closed-loop control system. The parameters of 3MW wind turbine are taken as an example for simulation, the results show that this method can accurately estimate the delay generated in the process of pitch control, and can still well compensate the delay caused by the system under the condition of regulating pitch angle.