Showing papers in "Eastern-European Journal of Enterprise Technologies in 2016"
Abstract: The problem of verification of indicators which are supposed to be used as criteria of efficiency of models of simple target operations is solved. For realization of such opportunity, it is offered to test the indicators on couples of reference models of simple target operations, the efficiency of which is calculated previously with the help of the developed technique and predictive indicator. Now more than one thousand indicators are developed, which the authors-developers define as efficiency indicators. As the criterion of efficiency is a global criterion of optimization, the indicator offered for the solution of optimization tasks has to provide an adequate assessment of efficiency of the optimized process in the whole range of management. This is particularly relevant for the automatic control systems. As a result of the research, it is established that the efficiency of target operations in some cases can be defined by using a method of a direct assessment of the process that is generated by the initial target operation. For this purpose, performance of a number of conditions is necessary: the studied target operation has to be simple; the compared operations have to be comparable relative to the starting investments; it is necessary to consider not only the data from the process generated by the cyclic performance of target operations, but also from the processes generated by the use of their target product. The received results allow revealing the indicators that can be used to solve the optimization problems by the criterion of efficiency. Such opportunity allows passing from a paradigm of process automation to full automation of management processes by the criterion of resource efficiency.
43 citations
TL;DR: The proposed approach for solving the problem of mathematical programming with not clearly defined parameters has the following benefits: complex criterion has a distinct meaning and the corresponding computational procedure is simple.
Abstract: A brief analysis of traditional methods of solving fuzzy problems of mathematical programming was carried out. The shortcomings of the known approaches, limiting their application for the problems of real dimensionality, were revealed. The solution of the problem is achieved with the use of a two–stage procedure. At the first stage, a usual optimization problem is solved, which is caused by the original problem with the replacement of fuzzy parameters with their modal values. In this case, standard technologies of solving the problems of mathematical programming are used. At the second stage, a distinct solution, which satisfies two special requirements, is searched for. First, this solution must minimally deviate from the modal, obtained at the first stage. Second, membership function of fuzzy value of the optimized function, corresponding to the solution, must have a minimum level of uncertainty. In this connection, a complex criterion, which contains two appropriate components, is formed for solving the problem. A parameter of regularization, which assigns the value of the weight coefficient, determining the value of components, is introduced into the proposed complex criterion. This regulating multiplier provides acceptable level of the ratio between contradictory requirements, corresponding to the components of the criterion. The proposed approach for solving the problem of mathematical programming with not clearly defined parameters has the following benefits. Complex criterion has a distinct meaning and the corresponding computational procedure is simple. The implementation of its first stage is ensured by a traditional set of tools of determined optimization. The problem of the second stage when using standard membership functions, as a rule, comes down to the problem of quadratic programming. The account of theoretical material of the work is accompanied by examples.
41 citations
TL;DR: The essence of an efficiency indicator which has cybernetic structure and successfully passed test on all classes of reference operations has been developed and results of use of the developed indicator as optimization criterion in the system of liquid portion heating have been given.
Abstract: The problem of development rates maximizing of any business structure is solved by system processes optimization, and the best choice taking from a set of available alternatives. In order to solve these problems, an indicator that can be trusted to a central place in the technology of the optimum solutions is needed. Especially it is urgent where full automation of control processes is necessary. This responsibility involves the careful selection and verification of the indicators claiming to be the optimization criterion. According to the retrospective analysis, in this issue it is possible to allocate two interconnected problems. The first problem is an uncertainty of the “optimization” concept. In fact, the optimization process, for today, is associated with extremum search of some function. In this regard, the second problem is related to the fact that as an optimization criterion, forming the function, it is proposed to use a variety of indicators. In this work the essence of an efficiency indicator is revealed. The structure of this indicator and the properties which such indicator has to possess are defined. A number of classes of reference operations were created. Each such class provides a possibility of testing those qualities which the efficiency indicator applying for a role of optimization criterion has to possess. The indicator which has cybernetic structure and successfully passed test on all classes of reference operations has been developed. Results of use of the developed indicator as optimization criterion in the system of liquid portion heating have been given. Definition for category “efficiency” and “efficiency indicator” has been given. The received results can be useful to developers of cross-disciplinary indicators, specialists in control processes automation and business processes optimization.
40 citations
TL;DR: Automated analysis of messages of users in a social network to form the status of psychological state of a personality based on the content analysis significantly reduces the time of finding a potentially promising employee among those applied taking into account his/her psychological portrait for a specific position.
Abstract: The approach is proposed to developing an information system of determining the psychological state of personalities based on the five personality dispositions (extraversion/introversion, amiability, integrity, neuroticism, openness to experience), which is based on the content analysis of the Internet resources where users leave their mark (social networks, forums, chats, etc.). In general, to form the status of psychological state of a personality based on the content analysis, it is necessary to solve four problems. First, it is necessary to collect content from various sources from the Internet. Then it is necessary to process it at the initial level (remove the tags, auxilary words, signs, special symbols, hyperlinks, pictures, etc. from the text). Then the content is filtered (to identify spam, detect duplication, format the content, etc.) and sorted out (comments to the comments, likes, posts) according to the statistics over a specific period. The last stage is conducting the content analysis of collected information, which is categorized by the stop-words (markers). To determine the psychological dispositions of a personality we implemented the developed method of the search and analysis of the marked words in the English and Ukrainian languages. We used the Potter stemming, lemmatising and the modified Potter stemming for the Ukrainian texts, designed by the authors. The tables of correlation between the marked words and psychological dispositions were developed. The information system is created for determining the psychological state of personality, based on the developed approach and the methods of the content processing. The system operates by analyzing the messages from the users in a social network based on the traits of the "Big Five". The system is designed in the form of a desktop program, which is the Internet service at the same time, and allows analyzing the psychological state of a particular user of a social network by his/her messages. All collected results are stored in the database. The results are displayed in the form of percent ratio for each trait, the number of tweets, as well as the most frequently used words related to these traits. Potential users of such systems are consulting and marketing companies. The collected and analyzed information on users may be used in hiring or promotion of products/services. Automated compilation of the personality models of users is helpful for social networks and Web services. It improves the quality and efficiency of context advertising, referral systems, recommendations and dating services. The in-depth knowledge of the audience is crucial for business and recruiting. The approbation of functioning of the constructed system was conducted. The results of the work of the system are satisfactory. Such an information system is recommended to use for searching employees for certain positions. Automated analysis of messages of users in a social network to form the status of psychological state of a personality based on the content analysis significantly reduces the time of finding a potentially promising employee among those applied taking into account his/her psychological portrait for a specific position.
39 citations
TL;DR: In this paper, the performance of Ni(OH)2 with the optimal parameters to be determined should be determined, and it has been demonstrated that high specific capacity is the most affected by α (or layered α+β) structure, optimal (average or low) crystallinity, introduction of activating additive and the ability of particle agglomerates to undergo breakdown into smaller particles during charge discharging.
Abstract: Nickel hydroxide is widely used as an active material for hybrid supercapacitors. To improve the characteristics of supercapacitors, Ni(OH)2 with the optimal parameters to be determined should be synthesized. For this, Ni(OH)2 samples were prepared by various methods: decomposition, homogeneous precipitation, electrochemical synthesis using slit diaphragm electrolyzer under various current densities, with diaphragm or membrane, carbonate activation, immediate ultrasound posttreatment and an industrial sample, prepared by chemical route. Structural properties of the samples were studied by Xray phase analysis, specific surface area – BET method by nitrogen adsorption, electrochemical characteristics – galvanostatic chargedischarge cycling in the supercapacitor mode. It has been demonstrated that high specific capacity is the most affected by α (or layered α+β) structure, optimal (average or low) crystallinity, introduction of activating additive and the ability of particle agglomerates to undergo breakdown into smaller particles during chargedischarge. Specific surface area has little influence on specific capacity. The sample prepared in slit diaphragm electrolyzer at 15.7 A/dm2 has a layered type of crystal structure, and the ability of particle agglomerates to undergo breakdown into smaller particles during chargedischarge, and showed the highest specific capacity of 650 F/g.
36 citations
TL;DR: In this article, the influence of process parameters of electrochemical chrome plating of steel parts: mass ratio of the solution component concentrations (C), current density (i), solution flow rate (v) and solution temperature (T) on the microhardness (Y h ), wear (Y w ), roughness and taper (Y t ) using mathematical experimental design is investigated.
Abstract: The analysis of methods of surface hardening to improve wear resistance and corrosion resistance of replacement parts of double-acting reciprocating pump hydraulics is performed. Application of electrochemical chrome plating of parts in the spilling solution, which provides wear-resistant coatings with high surface quality is justified. The influence of process parameters of chrome plating of steel parts: mass ratio of the solution component concentrations (C), current density (i), solution flow rate (v) and solution temperature (T) on the microhardness (Y h ), wear (Y w ), roughness (Y r ) and taper (Y t ) using mathematical experimental design is investigated. The optimum values of process parameters which provide maximum microhardness, minimum wear, minimum roughness and taper of the chromium coating are determined. It is found that the maximum microhardness of the chromium coating provides minimum wear. Optimum process parameters are within the factor space. To achieve minimum roughness and taper, process parameters are outside the space factor. Based on the results of studies, it is recommended to take the optimum process parameters of electrochemical chrome plating in the spilling solution as those that provide minimum wear of the coating: Y w =0.095 g: C=79.5; i=133.5 A/dm 2 ; v=114.7 cm/s; T=59.3 о С, and the necessary surface roughness and taper of the part is advisable to obtain in further machining operations.
34 citations
TL;DR: It was substantiated that in order to enhance effectiveness and transparency of decisions in MQHR, it is appropriate to use multicriteria optimizations based on the TOPSIS method, the advantages of which were shown.
Abstract: Under conditions of active development of innovative information technologies (IT) and eliminating the boundaries in providing educational services, human resources (staff, including IT specialists) turn into the main strategic resource of organizations, which ensures their long-term competitiveness and achievement of the set goals. Much emphasis in this problem is given to both the specific features of a recruiting company and to a high level of provision of educational services that meet international standards and requirements for the level of competences of would-be IT specialists. Therefore, the development of new conceptual approaches and promising information technologies of managing human resources acquires special relevance and practical significance. The article highlighted specific features of tasks of managing qualified human resources (MQHR), which allows identifying them as a task of multicriteria analysis and decision making in the fuzzy environment. A generalized conceptual model for decision making in the problems of MQHR was proposed. It was substantiated that in order to enhance effectiveness and transparency of decisions in MQHR, it is appropriate to use multicriteria optimizations based on the TOPSIS method, the advantages of which were shown. A modification of the algorithm for using TOPSIS for making recommendations in recruiting qualified human resources was proposed. The modification implies the integration of additional components of the content management in the decision making algorithm, which provides for the calculation based on the method of analysis of hierarchies (MAH) of coefficients of level or course of attained educational services. Using the TOPSIS and MAH methods and the scale of assessment of competence of qualified human resources, experimental calculations with ranking of alternatives were performed using the example of recruiting, which demonstrated effectiveness of the proposed approach.
33 citations
TL;DR: In this paper, the authors have shown that the largest values of acceleration acting on the wagon-platform with containers placed on it during a shunting collision occur in the presence of gaps between the fitting stops and fittings and amount, respectively, about 90 m/sµ and 110 mµ.
Abstract: In order to increase the volume of cargo transportation through international transport corridors that pass through Ukraine, container transportation has been developed. To ensure the safety of a wagon-platform with containers placed on it, the research of dynamic loads acting on them at shunting collision has been conducted in real operating conditions. The research results led to the conclusion that the largest values of acceleration acting on the wagon-platform with containers placed on it during a shunting collision occur in the presence of gaps between the fitting stops and fittings and amount, respectively, about 90 m/s² and 110 m/s². The approbation of obtained acceleration values was performed by computer simulation of the dynamics of a wagon platform with containers placed on it under the action of the longitudinal impact force of 3.5 MN on the back gauge of automatic coupling. Verification of the model was tested by the Fischer criterion. This revealed that the hypothesis of the adequacy of the model was not disputed. Conducted research will improve operational safety of the wagons in the combined transportation, and will motivate design of wagons of the new generation for use in combined international traffic.
32 citations
TL;DR: In this paper, a method for detecting near-zero apparent motion of objects on the series of CCD-frames using the XY-wise and coordinate-wise decision rules is developed.
Abstract: A computational method for detecting near-zero apparent motion of objects on the series of CCD-frames using the XY-wise and coordinate-wise decision rules is developed. The method is based on checking the statistical significance of the factor of speed of the object apparent motion on the studied series of measurements using the Student's t-test for coordinate-wise decision rules and F-test for XY-wise decision rules. This is the main feature of the developed computational method compared with the conventional decision rules based on the maximum likelihood criterion. The developed computational method for detecting near-zero apparent motion of the objects was tried and tested, and embedded in the block of inter-frame processing of the CoLiTec software package for the operational automated detection of new and tracking of the known asteroids, comets and faint celestial bodies. Using the CoLiTec software package and the proposed embedded computational method, the comet C/2012 S1 (ISON) — long-period sungrazing comet was discovered, which at the time of discovery was the object with near zero apparent motion.
32 citations
TL;DR: In this paper, the authors focus on the operating principle of the hydraulic equipment set for finishing works and propose a method of calculating specific energy consumption of the selected set components, which can be used by design engineers to further improve the performance of designed machines in terms of their rational energy consumption.
Abstract: The study focuses on the operating principle of the hydraulic technological equipment set for finishing works. The main objective of the study is to determine the amount of energy consumed in the process of the set operation. This energy is spent on mixing the finishing mortar and on the work output of the mortar pump piston when it is acting on the mortar to create the required feed pressure in the pressure main. We consider a scheme of energy consumption of the operating equipment set and propose a method of calculating the specific energy consumption of the selected set components. The method consists in calculating the energy consumption of each component and the total energy input, which allows determining the required capacity of the power unit. The research findings allow calculating the energy input in the process of operation and, thereby, estimating the energy balance of such unit. They can be used by design engineers to further improve the performance of the designed machines in terms of their rational energy consumption. The proposed method allows analyzing the share of energy consumption of each element of the hydraulic equipment set and outlining steps to further improve the parameters of the hydraulic circuit.
28 citations
TL;DR: In this paper, a mathematical model of technological equipment with the rotary hydraulic drive as an object of automated control is developed, which is a set of linear dynamic links with characteristic parameters, such as the time constant of the pump displacement control process, the transmission coefficient for the tilt angle of the washer (cylinder block) by the control voltage, transmission coefficient of the drive power section; transmission coefficients for the angular velocity by the loading point.
Abstract: The problems of automation of control processes of technological equipment with the rotary hydraulic drive are considered. The purpose of the paper is synthesis and study of the ACS for equipment that allows for the stochastic disturbance and observation noise.The mathematical model of technological equipment with the rotary hydraulic drive as an object of automated control is developed. The mathematical description is a set of linear dynamic links with characteristic parameters, namely the time constant of the pump displacement control process; the time constant of the drive power section; transmission coefficient for the tilt angle of the washer (cylinder block) by the control voltage; transmission coefficient of the drive power section; transmission coefficient for the angular velocity by the loading point.The ACS of equipment that allows for the observation noise and stochastic disturbance of the control object is synthesized. The solution of the problem of the stochastic optimum linear system with incomplete information about the state according to the method of distribution is divided into two: the problem of synthesis of the optimum supervisor and the deterministic problem of synthesis of the optimum system. To develop the optimum linear controller, the dynamic programming method is used.The study of dynamic characteristics of the ACS is carried out. It is shown that in the range of possible disturbance options, the Kalman-Bucy supervisor performs the function of optimum filtering, reduces the transient duration and provides necessary equipment control quality. The calculations of transients for angular displacement and angular velocity at different values of the transmission coefficient of the pump displacement control unit and the transmission coefficient of the controller are made. Recommendations for selecting the optimum values of transmission coefficients allowing for the features of the technological purpose of equipment are given.The research results can be used to improve the technological equipment, particularly to expand functionality and enhance dynamic characteristics.
TL;DR: In this article, the influence of technological parameters of reinforced steel parts with tungsten carbide particles in the casting process on the concentration and the wear of the working area using the mathematical experimental design is investigated.
Abstract: Analysis of surface and three-dimensional reinforcement methods to enhance the wear-resistance of parts is performed. The advantages of centrifugal reinforcement of the part blanks with two mutually perpendicular axes of rotation of the ceramic mold to produce the reinforced zone with desired properties are substantiated. The influence of technological parameters of centrifugal reinforcement of steel parts with tungsten carbide particles in the casting process on the concentration and the wear of the working area using the mathematical experimental design is investigated. Second-order regression models for dependencies of concentration and wear on the technological process parameters: the number of rotations around the horizontal and vertical axes of the ceramic mold, heating temperature of the ceramic mold and heating temperature of reinforcing tungsten carbide particles are built. The optimum values of frequencies of rotation around the horizontal and vertical axes, heating temperatures of the mold and reinforcing particles, which provide the maximum concentration of tungsten carbide particles in the working area and minimum wear are determined. It is found that the concentration of tungsten carbide particles in the working area and wear are affected by the kinematic components of technological parameters more than temperature ones. For centrifugal reinforcement of inserted drilling bit teeth with 1.0 mm tungsten carbide particles with two mutually perpendicular axes of rotation of the ceramic mold, the following technological parameters are optimal: nx=217 rpm; nz=702 rpm; Tф=270 oC; Ta=208 oC providing a maximum tungsten carbide concentration in the working area and minimum wear. The research results are useful in the development of technological processes of manufacturing turned parts with the reinforced working area, namely disc and tooth rolling cutters, milling cutters, blade drilling bits, inserted drilling bit teeth.
TL;DR: In this article, the case depth and surface hardness of 38Cr2MoAl А steel during ion nitriding were modeled in the form of quadratic polynomials.
Abstract: Modeling of the ion nitriding process allows solving many problems of operations management, forecasting of results and development of new treatment regimes, which is an urgent issue today. The goal of the paper was modeling of the case depth and surface hardness of 38Cr2MoAl А steel during ion nitriding. The experimental data showed that the case depth varies from 20 to 620 µm in the ion nitriding temperature range of 500-560 °С and duration of 1-12 hours, with the surface hardness varying from 8 to 12 GPa. The mathematical models in the form of quadratic polynomials, describing the dependence of the nitrided case depth and surface hardness on the temperature and duration of thermochemical treatment were obtained. The graph-analytical description of variations in the nitrided case depth and surface hardness depending on variations in temperature and duration of treatment, which allows determining the specific conditions of ion nitriding 38Cr2MoAl steel is constructed.
TL;DR: In this paper, the influence of laser processing conditions on the properties of 40, 40Cr ǫ and 38Cr2Moǫ steels for surface hardening was investigated.
Abstract: Development of new technologies to improve the durability of high-wear parts is urgent. The goal of the study is to investigate the influence of laser processing conditions on the properties of 40, 40Cr and 38Cr2MoАl steels for surface hardening. Comparative analysis of hardness parameters after the through hardening, hardening and tempering, and laser hardening of steels showed that laser hardening improves the hardness by 1.3–1.35 times compared to the through hardening and by 1.7–2.32 compared to the steel hardness after hardening and tempering. The mathematical patterns of the influence of laser beam travel speed on the case depth depending on the steel grade in the form of quadratic and cubic polynomials are found. These patterns allow predicting the case depth values. Microhardness distribution over the cross section in the zone of local laser hardening showed that the highest hardness values for steels correspond to the zone of the most dispersed martensite, further increase in grain dispersion reduces the hardness parameters. Due to the local surface hardening of 40, 40Cr and 38Cr2MoАl steel parts by laser hardening, operational properties of parts in further operation can be improved. This method is suitable for hardening difficult-to-access areas of parts, local contact areas. The hard case is formed through laser hardening, the matrix of the part remains viscous and softer. This combination of properties improves the durability of parts.
TL;DR: In this paper, a process of twin forging of eye-bolt forgings was designed as well as the arrangement of the forging facilities, which can ensure metal saving at 21.7 % level.
Abstract: A possibility of application of longitudinal bending (buckling) as an economical way of profiling workpieces, ensuring replacement of pinching impressions and edgers was shown for manufacturing of eye-bolt forgings. For realization of this method of impression-free profiling of blanks, a process of twin forging of eye-bolt forgings was designed as well as the arrangement of the forging facilities. The peculiarity of this process is that the cut-off blank is upset, it loses its stability and thus obtained profiled semi-finished product is turned over on its side and eventually it is put inside the impression for simultaneous forging of two forgings from one blank. It was found that profiled semi-finished items acquired the desired shape at the degree of blank’s upsetting equal to 39 %, the central angle between the twin eye-bolts forgings being 54° and it had been taken into account for the dies’ design. Experimental forming of eye-bolts forgings according to the proposed and conventional processes on physical lead models of blanks, which helped to find out that the proposed technical solution, can ensure metal saving at 21.7 % level. Comparison of these two methods revealed improved technical and economic indices of the new process; particularly the coefficient of metal consumption at cutting was raised by 1.4 %, the quotient of output of quality forgings by 21.1 % and coefficient of application of forgings metal along the consumption rate by 27.9 %.
TL;DR: In this article, the authors present a cognitive model of the interaction of knowledge in project management, using a Markov chain with four discrete states: customer, team, training and in-depth knowledge systems.
Abstract: World practice to overcome the lack of knowledge and meet educational needs under the terms of career growth and personal improvement and development is based on the modern paradigm of continuous postgraduate education ‑ lifelong learning (LLL). In the context of learning management, the analysis of features and synthesis of the structure of interaction of the basic process entities as knowledge holders were performed. Referring basic knowledge holders ‑ team, customer, training and in-depth knowledge systems to certain discrete states, which the system may take, allows representing the system using a Markov chain with four discrete states. A directed graph of the Markov chain reflects the secondary projection of a communication on the knowledge space rather than the physical interaction of the knowledge holders. Markov chain transition probabilities for the project environment define its characteristics that vary in discrete time by the steps in the form of a set of state probabilities. Cognitive properties of the model which is based on the Markov chain makes it possible to set some specific values of the transition probabilities of the system. The results obtained are the justification for continuing training and acquiring additional education of personnel in the deficit of knowledge that is necessary for the implementation of unique projects. Using the developed cognitive model of the interaction of knowledge in project management, the paradigm of “lifelong learning” was justified. The knowledge management structure includes four fundamental entities: the customer, the team, training and in-depth knowledge systems of the knowledge owners. These entities are in a constant process of knowledge sharing. The systems of training and in-depth knowledge play a role of generating new knowledge, which was absent in the project environment. Continuing education ideally is aimed at balancing between the needs of society and the motivational structure of personality that actually should be implemented through the mechanisms of the influence of education on the socialization of the individual.
TL;DR: In this article, a dynamic model of the thermal sensor of a fire alarm is presented in the form of the differential equations in the state space for the thermoresistive sensitive element.
Abstract: The theoretical analysis of the generalised circuit of the thermal sensor has shown that it is a converter of information of the resistive sensitive element into the corresponding voltage, which is carried out by the bridge measuring circuit. The dynamic model of the generalised circuit of the thermal sensor of fire alarm is presented in the form of the differential equations in the state space for the thermoresistive sensitive element in the form of a thin plate is developed on the basis of the generalised circuit of the thermal sensor. The private model of the thermal sensor of the first approximation in the state space is received for values Bi≤1. The given model allows researching the dynamic accuracy of the thermal sensor in various conditions of the fire alarm use taking into account the casual ambient temperature indignations. The influence of parameters of the bridge circuit and also of the sensitive element of the thermal sensor on dynamic accuracy in various conditions is investigated on the basis of this model. The analysis of dependence of the value of the second initial moment of an error on the considered characteristic parameters of the thermal sensor in dynamic conditions in the presence of casual temperature indignations of various intensity has shown that there are minimum values of the second initial moment of an error. Generally the minimum values of the second initial moment of an error depend on the characteristic parameters of the thermal sensor, current time and temperature conditions in the environment, characterised by the fire centre. There are possibilities of maintenance of invariance in time of the second initial moment of an error. The dependences of the optimum value of the characteristic parameter B 1,1opt of the thermal sensor on speed of temperature increase caused by the fire centre, and also the intensity of masking casual temperature indignations on the object are received for this case. The received results allow to predict the expected accuracy for existing thermal sensors in various conditions of use, and also to develop optimum thermal sensors of single fire alarms for the guaranteed detection of low-power fire for real objects’ protection.
TL;DR: In this paper, the impact of uneven load flow patterns on the energy parameters of transportation and the resource of the belt conveyor during heavy mining of coal was investigated, and the effect of the size and type of the load flow and the load weight on energy consumption and the capacity of the conveyor was assessed.
Abstract: The object of the present study is the process of transporting the mined bulk by a belt conveyor during intensive coal mining. The subject of the study is the impact of uneven load flow patterns on the energy parameters of transportation and the resource of the belt conveyor during heavy mining of coal. The aim of the study is to assess the impact of the weight of the load that is transported by a conveyor belt on the drive motors loading and energy consumption during intensive coal mining. The research is performed through a statistical analysis of experimental results obtained by the Dongiprovuglemach institute (Ukraine) regarding the load flow and the capacity of the belt conveyor 2LU120V used by the mine Dovzhanska-Capital (Sverdlovsk, Ukraine). The capacities of drive motors were considered through a regression analysis. A correlational and spectral analysis was applied to consider the load flow, the load weight, and the capacities of the drive motors. The study has specified the estimated drag coefficient in the movement of the conveyor belt under conditions of intensive mining of coal. Specific energy consumption for transporting the mined bulk by the conveyor was estimated regarding the loading of the belt. The work was done to assess the effect of the size and type of the load flow and the load weight on energy consumption and the resource of the conveyor and to justify a further increase of the technical level of belt conveyors. The results show substantial irregularities in the load flow and the transported load weight, their impact on the amount and type of an uneven loading of the drive motors, and specific energy consumption for transportation and the conveyor resource. The study has shown that if the loading is small a bigger load is imposed on the drive motor that is located in the place of the belt running off the drive; if the load in big, a bigger load is imposed on the drive motor that is located in the place of the belt running onto the drive. The main dispersion of the load flow occurs at low frequencies corresponding to the duration of the technological cycle of extracting and transporting coal. When the modes of the conveyor operation are close to the maximum load of the belt, energy is least of all consumed for transporting the load. If the loading is reduced, there is a hyperbolic increase in specific energy consumption for transportation. The drag coefficient of the conveyor belt movement, obtained by the experiment data on the capacity value of the idly running conveyor, is significantly higher than the value that is suggested by the method of a technological calculation of the process. This factor should be taken into account while determining the capacity of a drive and calculating the traction of the machine. The results can be used for creating belt conveyors within mining systems of an improved technical level for highly efficient intensive coal mining.
TL;DR: In this paper, the most dangerous sections of the profiles of the rims of wheels, which, in the process of deformation, obtain compressive radial deformations, were investigated.
Abstract: Questions of experimental study regarding the stress-strained state in the radial rotary method of producing the steel rims of wheels are examined. The physical simulation of the process of profiling the rims is performed on the installation, designed especially for these purposes. The models of the narrow-profile and wide-profile rims of wheels were tested. The grids method was applied for conducting the experiments. The obtained information was processed by the methods of mathematical statistics and probability theory. The results of experimental data made it possible to arrive at a conclusion about the most dangerous sections of the profiles of the rims of wheels, which, in the process of deformation, obtain compressive radial deformations, which confirms the studies conducted previously. The largest deformations occur in the places of radius couplings of the profile, deformations increase from one transition to the next and their total magnitude can exceed the permitted by 20 % of the initial thickness of the workpiece. No essential difference between the two schemes of profiling the rims of wheels was revealed.
TL;DR: Comparative analysis of four different techniques of redundant signals processing including technology of “virtual” gyro signals processing in application to the differential vibratory gyroscope of the new type with two measuring channels of angle rate with opposite signs is carried out.
Abstract: Advantages of differential Coriolis vibratory gyroscope of the new type with two measuring channels of angle rate with opposite signs that provides redundant measuring information about angle rate are analyzed. Comparative analysis of four different techniques of redundant signals processing including technology of “virtual” gyro signals processing in application to the differential vibratory gyroscope is carried out. Importance of creation of redundant information processing techniques is caused by distinction of the differential vibratory gyroscope from other microelectromechanical gyros, for example, tuning fork gyro, in that it has two output signals, which come from the single resonator and correspond to angle rates with opposite signs. As a result redundant output information processing techniques were obtained. This information comes from the differential vibratory gyroscope output and is formed by subtracting of two measuring channel signals. The algorithm of “virtual” gyro redundant output information processing was modified. The algorithm differs from known ones by calculation of interchannel correlation matrix in online manner. This leads to decrease of angle rate measuring random error and to decrease overshoot in conditions of abrupt change of angle rate. The obtained results are important and useful for application of differential vibratory gyroscopes in stabilization systems and angular motion control. This is caused by high requirements to accuracy and ability to function in hash environment.
TL;DR: In this article, an innovative method for the creation of rapid hardening building composites with multifunctional purposes and specified properties under different operating conditions is their nanomodification, which is based on the principles of directional control and control over the processes of structure formation of material, as well as over kinetics and mechanism for chemical interactions at the early stages of the hardening process of cement matrix.
Abstract: An innovative method for the creation of rapid hardening building composites with multifunctional purposes and specified properties under different operating conditions is their nanomodification. This technique is based on the principles of directional control and control over the processes of structure formation of material, as well as over kinetics and mechanism for chemical interactions at the early stages of the hardening process of cement matrix. Comprehensive assessment of particle size distribution of ultrafine mineral additives by the indicator of differential coefficient of surface activity was carried out. Physical and mechanical properties of the nanomodified Portland cement composition, which contain ultrafine mineral additives, polycarboxylate superplasticizer, alkaline containing accelerator of hardening, as well as nanoscale particles of calcium hydrosilicate, were investigated. Peculiarities of the phase composition and microstructure of nanomodified Portland cement composition were established by physical and chemical analysis methods. It was established that the examined Portland cement compositions are characterized by intensive development of early strength, and by the indicator of standard strength they are related to high strength binder. It is demonstrated that acceleration of the hardening processes of nanomodified Portland cement compositions is due to the optimization of particles packing of the system, the presence of energy-active particles in the composition of mineral additive, increasing of liquid phase alkalinity, stimulating of nucleation processes in the inter-grain space due to heterogeneous or homogeneous nucleation, accelerating of reactions associated with pozzolanic activity of ultrafine additives. A widespread using of rapid hardening concretes based on the nanomodified Portland cement compositions with high strength at an early age will provide for an increase in efficiency of erecting monolithic structures, road infrastructure objects, of manufacturing precast reinforced concrete products, of carrying out repair and restoration works, including those under different temperature conditions.
TL;DR: In this paper, a multi-stage formation mechanism of tripolyphosphate coat has been proposed, which includes three stages: at the start the adsorptive film is formed, that afterwards is modified two times, accompanied by a change of properties and composition.
Abstract: The mechanism, protective properties, microstructure, phase composition of coats on steel have been investigated. According to the developed method, the coats were deposited potentiodynamically and potentiostatically in an aqueous solution of sodium tripolyphosphate. Based on the results of electrochemical studies, it has been established, that on potentiodynamic curves, characterizing the corrosion behavior of low-carbon steel in an aqueous sodium TPP solution, up to three passivation plateaus can be observed. The multi-stage formation mechanism of tripolyphosphate coat has been proposed. The mechanism includes three stages: at the start the adsorptive film is formed, that afterwards is modified two times, accompanied by a change of properties and composition. By using the methods of optical and scanning electron microscopy, X-ray diffraction, it has been established that the coat formed in an aqueous Na TPP solution by the potentiodynamic method under conditions of complete passivation, is composed of two layers: first – thin, compact layer, that contains a crystalline phase of phosphate nature, and second – thick hydrophilic layer, capable of drying. Such coat possesses the best protective properties in 0.1 N Na 2 SO 4 solution, that models conditions of atmospheric corrosion. The nature of the electrochemical formation mechanism of tripolyphosphate coats and features of their structural and phase composition have been established. The further studies will be directed at the development of effective deposition methods of tripolyphosphate coats with estimated set of properties for the protection of metal goods from atmospheric and high-temperature gas corrosion.
TL;DR: In this article, a new method for the extraction of amber out of amber-containing sand field was proposed, providing for higher efficiency of its recovery while negative impact on the natural environment is reduced.
Abstract: Patterns of interrelation between the ambercontaining mining mass and vibrohydraulic intensifier were defined with the substantiation of its technological parameters for creating the required density of the medium, which provides for maximal extraction of amber. Existing methods and methods for the extraction of amber were analyzed and a new method for the extraction of amber out of ambercontaining sand field was proposed, providing for higher efficiency of its recovery while negative impact on the natural environment is reduced. Laboratory and field studies were carried out on ambercontaining sand fields in RivnenskyVolynsky region with the purpose of improvement of existing technologies of extraction of amber. When carrying out experimental research, we determined the main technological parameters of hydromechanical method of amber extraction and determined the patterns of influence of water and air on the liquefaction of ambercontaining sandy media when an array is exposed to the action of a vibrohydraulic intensifier, during which a maximal speed of amber recovery to the surface is achieved. In the process of field research, we implemented the latest technology and achieved maximum extraction of amber in the deposit, which is 90–95 % of the total mass.
TL;DR: In this paper, the authors conducted an analysis of losses in the output parameters of solar cells based on CdTe/CdS, which are caused by the design features of instrument structure and by the photoelectric processes that occur in its volume when absorbing light.
Abstract: We conducted analysis of losses in the output parameters of solar cells based on CdTe/CdS, which are caused by the design features of instrument structure and by the photoelectric processes that occur in its volume when absorbing light. Based on the carried out analysis, the ways for the improvement of SC are determined for the purpose of increasing the efficiency of a photo element. The approaches to increasing the efficiency of a photo element are examined, which were previously realized by scientists. It was established that, despite the implemented technologies, efficiency of the obtained samples does not reach theoretical maximum (η theor ≈29 %). A basic technological approach, which was realized by many authors, when creating the low ohmic contacts to SC based on CdS/CdTe is the formation of tunnel contacts, using in this case thin films that contain copper or copper chalcogenide. However, the diffusion of copper into the base layer leads to the degradation of output parameters of the film SC based on CdS/CdTe. That is why we carried out comprehensive studies, aimed at designing back contacts to the CdTe base layers for the creation of highly effective, degradation-resistant solar cells. It is experimentally established that in the absence of the copper layer at the back surface or in the absence of the annealing process after the formation of a back contact, efficiency of the film ITO/CdS/CdTe/Cu/Au SC is limited at the level of 3–4 % due to the work of instrument structure in the regime of "open diode". In the course of formation of quality Cu/Au tunnel contact, the SC efficiency increases to 10,4 %.
TL;DR: In this paper, a method for indirect measurement of the current concentration of oxygen in the air whose magnitude quantity depends on meteorological environmental parameters: temperature, absolute pressure and relative humidity was proposed.
Abstract: This paper presents a new approach to control and mange the process of fuel combustion in the boiler units. Ways to increase the efficiency of combustion of fuel materials are examined. We proposed a method for indirect measurement of the current concentration of oxygen in the air whose magnitude quantity depends on meteorological environmental parameters: temperature, absolute pressure and relative humidity. Experimental research was conducted to compare direct and indirect methods of measuring the volumetric concentration of oxygen in the air. We calculated the uncertainties of measurement of the volumetric concentration of oxygen in the air for the direct and indirect methods. An estimation of the extended expanded uncertainty of the indirect method of measurement was carried out by the imitation simulation using the Monte-Carlo method. It is demonstrated that relative air humidity exerts the largest influence on the extended expanded uncertainty of measuring the volumetric concentration of oxygen. A comparison of the methods of measuring the volumetric concentration of oxygen revealed that the extended expanded uncertainty of the indirect method is less than that of the direct method. We proposed functional dependence of an increase in accuracy of the measurement of excess air coefficient that is based on the calculation of the current concentration of oxygen in the air, which will make it possible to ensure highly effective fuel combustion in the boiler units at any regimes of its functioning.
TL;DR: Applying the ontological modeling methods as a basis for analysis provides a holistic view of the causes of uncertainties for various stages of the SA formation process, makes it possible to analyze their interdependence, create and re-use knowledge about the causesof uncertainties for specific application areas.
Abstract: Situational awareness as the understanding of the system environment is a mandatory part of any decision support system. Formation and maintenance of situational awareness is a complex process. It comprises the stages of sensor data collection and interpretation, as well as updating of knowledge about the current situation for making correct decisions. However, all stages of this process are subject to various uncertainties and errors. They affect the knowledge about the environment and correctness of decision making using this knowledge. Various types of uncertainties have been researched and formalized. The work deals with the study and formalization of uncertainties that arise at different stages of situational awareness formation and reduction of adverse effects. The paper analyzes various models for defining and presenting the situational awareness formation process in order to find a common platform and mechanisms related to different process stages. Existing classifications, manifestations and influence of uncertainties on situational awareness at various stages of its formation are also discussed. The paper proposes methods to reduce the impact of uncertainty at all stages. The results of the analysis are appropriate for use in intelligent decision support systems for reducing the impact of different types of uncertainties in the process of situational awareness formation. Applying the ontological modeling methods as a basis for analysis provides a holistic view of the causes of uncertainties for various stages of the SA formation process, makes it possible to analyze their interdependence, create and re-use knowledge about the causes of uncertainties for specific application areas.
TL;DR: The study shows that the introduced known formal description of rough sets can be interpreted in terms of fuzzy sets, which makes it possible to solve many problems of rough mathematics by the developed apparatus of fuzzy mathematics.
Abstract: The study shows that the introduced known formal description of rough sets can be interpreted in terms of fuzzy sets. This makes it possible to solve many problems of rough mathematics by the developed apparatus of fuzzy mathematics. The authors suggest a way of describing rough numbers with the help of membership functions of fuzzy numbers. The study specifies the chosen type of membership functions and the method of calculating their parameters. The algebra of fuzzy numbers is adapted to perform operations with numbers that are described roughly. The obtained elements are formulae for calculating the expected values and variations of rough numbers. These correlations are simplified for the most realistic special cases. A possibility is considered for solving roughly given optimization problems. A procedure is described for reducing an optimization problem with rough parameters to a usual problem of mathematical programming. An example is given on solving a linear programming problem whose parameters are determined roughly. The rough problem parameters are described with functions of an (L-R) type. It is suggested that the problem should be solved on the basis of the introduced complex criterion. The numerical value of the criterion takes into account the extent of closeness of the obtained result to the modal solution as well as the level of compactness of the membership function of the resulting value of the objective function.
TL;DR: The resulting technical solution in the form of the controller for registering passenger flow of public transport of the system for managing transport flows of a "smart" city is characterized by low cost, required accuracy of calculating passengers and is the optimal project solution with wide functional capacities.
Abstract: A structure of the controller for registering passenger flow of public transport was developed, which includes the single board computer Raspberry Pi; GSM module; GPS module; controller of battery powered device; controller of the emergency restart of the device; button for registering passengers enjoying privileges; camera for registering passengers enjoying privileges and camera for registering passenger flow in a transportation vehicle. A built structure is characterized by the modular organization, which makes it possible to quickly upgrade the designed device. An algorithm of functioning of the controller of registering passenger flow of public transport and specialized software for implementing the functions of the controller were developed. A special feature of the software is the possibility of expanding functionality of the designed device in the process of upgrading the controller. Programming of the microcontroller was perforned in the language C, and programming of the controller based on Raspberry Pi 2 Model B was performed in Python. We built a model of functioning of the controller based on the Petri networks, which allows exploring dynamics of the system and identifying all possible states of the designed system. Authors developed technical support of the controller for registering passenger flow of public transport on the base of the single board computer Raspberry Pi, which ensures competitive price and the required functionality of the project solution. The resulting technical solution in the form of the controller for registering passenger flow of public transport of the system for managing transport flows of a "smart" city is characterized by low cost, required accuracy of calculating passengers and is the optimal project solution with wide functional capacities. The designed device was implemented and tested at the auto transportation enterprises "Mens-Auto" and "Etalon" in Ternopil (Ukraine).
TL;DR: In this article, a map of spatial variability in fractal dimensionality of fracturing in the labradorite deposits of Ukraine was produced, the use of which will make it possible to increase efficiency of discovering new labradoritic deposits, which will meet certain quality requirements.
Abstract: The technique of fractal analysis of regularities in the fracturing formation for various deposits or their sections, which is based on the comparison of values of fractal dimensionality of the roses of fracturing, was developed. The groups of labradorite deposits were distinguished by index of fractal dimensionality, which allows developing standard technological solutions for each group in order to enhance the effectiveness of quality and productivity control over technological complexes. A map of spatial variability in fractal dimensionality of fracturing in the labradorite deposits of Ukraine was produced, the use of which will make it possible to increase efficiency of discovering new labradorite deposits, which will meet certain quality requirements The construction of this map will allow enhancing efficiency of the interpretation of conditions for the formation of particular deposits. The patterns of change in fractal dimensionality at the different structural levels were established and the methods for their prediction were developed, which will make it possible, by the results of exploring fractal dimensionality at one of the structural level, to predict their values for others to optimize the process of control over geological exploration and extraction operations. As a result of the performed experimental studies, the influence of fractal dimensionality of fracturing in the blast-hole drilling zone on the productivity of the process was proved. We created objective function of optimal process to control technological processes, based on geostructural and technological indices that were evaluated by generalizing index of fractal dimensionality. The objective function of optimal process of drilling the fractured array, which includes indices of fractal dimensionality of the drilling zone, was proposed.
TL;DR: In this article, an analytical expression of dependency of the quantity of cracks on the strike azimuth in the form of polynomial of the second degree was obtained to predict the direction of development of mining and management of the processes of extraction of decorative stone.
Abstract: As a result of the performed research into regularities of formation of fracturing of deposits of labradorite, we identified the main types of the samples describing the elements of occurrence, and formed the reference samples, the analysis of which allowed us to substantiate the optimal methods of cluster analysis for selecting the systems of fracturing. To predict the direction of development of mining and management of the processes of extraction of decorative stone, we obtained analytical expression of dependency of the quantity of cracks on the strike azimuth in the form of polynomial of the second degree. The possibility of forecasting the quantity of cracks, proved in the work, depending on the strike azimuth of vertical cracks based on the mathematical description of the given dependence by analytical expression will make it possible to increase the efficiency of planning of mining works at the enterprises that use technologies, the efficiency of which is determined by the vertical fracturing. These are, first of all, crack-formation technologies, for which anisotropy and defectiveness of array play a crucial role. For the estimation of prospects of development of deposits, or separate sections, we proposed the new cluster-geometric technique of determining the blockiness and presented the example of its implementation for the conditions of Nevyrivskiy deposit of labradorites. In addition, the proposed technique makes it possible to estimate the probability of each of the obtained results, which significantly increases efficiency of risk assessment when designing mining works. It also allows increase in the degree of taking account of the genesis of fracturing and mutual angular correlations between the systems of fracturing, which provides for the possibility to increase the accuracy of assessment of quality of both entire deposit and its separate sections.