Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-41-1
The work is devoted to the review and analysis of resources of scientific information, the study of the possibilities of developing additional information arrays based on existing sources of scientific and scientometric information. As part of the work, approaches are proposed for storing scientometric information, methods for obtaining data, which will optimize the time of working with information and attract less resources for the implementation of work on the search for scientific information and its subsequent processing. The result of the work is a computer model that provides the ability to store scientific information in the database, as well as the use of various functions as a database administrator and user rights through the developed client C ++. The offered model of accounting for scientific activity has the following functional capabilities of software modules: introduction of new and removal of outdated information into a database; submitting information based on some criteria. The architecture of a computer model consists of such software modules as the user role definition module, the database administrator module, and the user module. The model works with information arrays, which are formed on the basis of resources and contain bibliometric and scientometric information and can act as parameters that be able to influence decision making and expand the range of possible cooperation of scientists. The application of the developed computer model allows organizing a flexible search for scientific information in the field of education.
{"title":"Computer model of accounting of the scientific activity of the education system","authors":"","doi":"10.26565/2304-6201-2019-41-1","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-41-1","url":null,"abstract":"The work is devoted to the review and analysis of resources of scientific information, the study of the possibilities of developing additional information arrays based on existing sources of scientific and scientometric information. As part of the work, approaches are proposed for storing scientometric information, methods for obtaining data, which will optimize the time of working with information and attract less resources for the implementation of work on the search for scientific information and its subsequent processing. The result of the work is a computer model that provides the ability to store scientific information in the database, as well as the use of various functions as a database administrator and user rights through the developed client C ++. The offered model of accounting for scientific activity has the following functional capabilities of software modules: introduction of new and removal of outdated information into a database; submitting information based on some criteria. The architecture of a computer model consists of such software modules as the user role definition module, the database administrator module, and the user module. The model works with information arrays, which are formed on the basis of resources and contain bibliometric and scientometric information and can act as parameters that be able to influence decision making and expand the range of possible cooperation of scientists. The application of the developed computer model allows organizing a flexible search for scientific information in the field of education.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-43-07
Considerable number of studies and publications is devoted to issues of dynamic behavior of liquids, the impact on the surface tension of a liquid in partially filled tanks in particular. The study of liquid vibrations in partially fluid-filled cylindrical containers with the presence of a free surface is an important technical task. The influence of the free surface curvature of the tank filler on the oscillation frequency is taken into account. It is assumed that the liquid is incompressible and inviscid, and its motion is irrotational. The method to solve a boundary value problem for determining fluid oscillations in a reservoir has been developed, and an integral presentation of an unknown velocity potential is proposed. The geometrical characteristics of the free liquid surface have been determined. It is taken into account that the free liquid surface deviates from the equilibrium position and assumes a spherical shape. A system of singular integral equations has been obtained for unknown values of the potential and flow. The method of boundary elements with constant approximation of an unknown density on the elements has been used to solve the system numerically. The oscillation frequencies for the zero harmonic are determined in accordance with the level of the free-surface elevation. It has been determined that the deviation of the free surface shape from the flat and even a slight rise in the free surface level leads to noticeable changes in the vibration frequencies. The vibrational modes obtained in the study mostly coincide with the modes for a flat free surface and can serve as the basic system of functions in the studies of free and forced fluid vibrations in tanks, as well as, in the study of the intrinsic and forced sloshing in the reservoirs provided surface tension is taken into account.
{"title":"Construction of basic functions for problems of fluid oscillations in a tank","authors":"","doi":"10.26565/2304-6201-2019-43-07","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-43-07","url":null,"abstract":"Considerable number of studies and publications is devoted to issues of dynamic behavior of liquids, the impact on the surface tension of a liquid in partially filled tanks in particular. The study of liquid vibrations in partially fluid-filled cylindrical containers with the presence of a free surface is an important technical task. The influence of the free surface curvature of the tank filler on the oscillation frequency is taken into account. It is assumed that the liquid is incompressible and inviscid, and its motion is irrotational. The method to solve a boundary value problem for determining fluid oscillations in a reservoir has been developed, and an integral presentation of an unknown velocity potential is proposed. The geometrical characteristics of the free liquid surface have been determined. It is taken into account that the free liquid surface deviates from the equilibrium position and assumes a spherical shape. A system of singular integral equations has been obtained for unknown values of the potential and flow. The method of boundary elements with constant approximation of an unknown density on the elements has been used to solve the system numerically. The oscillation frequencies for the zero harmonic are determined in accordance with the level of the free-surface elevation. It has been determined that the deviation of the free surface shape from the flat and even a slight rise in the free surface level leads to noticeable changes in the vibration frequencies. The vibrational modes obtained in the study mostly coincide with the modes for a flat free surface and can serve as the basic system of functions in the studies of free and forced fluid vibrations in tanks, as well as, in the study of the intrinsic and forced sloshing in the reservoirs provided surface tension is taken into account.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-44-04
The problem of determining a number of cycles to failure for structural elements having technological holes of circular shape and weakened by cracks is considered. It is assumed that the structure is subject to cyclic loading (tension-compression) with given frequencies and amplitudes. A technique for determining stress intensity factors for the structural element with two symmetrical cracks adjoining a contour of hole has been developed. The problem of determining the stress intensity factor has been reduced to solving a singular integral equation. For the numerical solution of this equation, the boundary element method has been used. The formulas for the effective numerical simulation of singular integrals with singularities of the Cauchy and Hadamard type have been obtained. The solution accuracy of the considered singular equation is investigated. Boundary elements with different density approximations are considered. It has been established that the use of boundary elements with a cubic approximation of density leads to a significant increase in the solution accuracy. Densities appearing as unknown functions in the considered integral equations are used to calculate stress intensity factors. Comparison of the analytical and numerical solutions of the considered singular equation, as well as the analytical and numerical values of the stress intensity coefficients has been performed. The initial crack length starting crack development has been determined by using the threshold value of the stress intensity factor. The critical number of loading cycles leading to cracks of an unacceptable size has been calculated based on the Paris criterion. This critical number of cycles is a characteristic of durability. To compare the durability characteristics, the problems of determining the critical number of cycles for plates with single isolated cracks and with crack chains are considered. It has been established that at the same loading level, the smallest critical number of cycles corresponds to a structural element with cracks in the vicinity of technological holes.
{"title":"Calculation model for assessing the durability of structural elements in the presence of holes and cracks","authors":"","doi":"10.26565/2304-6201-2019-44-04","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-44-04","url":null,"abstract":"The problem of determining a number of cycles to failure for structural elements having technological holes of circular shape and weakened by cracks is considered. It is assumed that the structure is subject to cyclic loading (tension-compression) with given frequencies and amplitudes. A technique for determining stress intensity factors for the structural element with two symmetrical cracks adjoining a contour of hole has been developed. The problem of determining the stress intensity factor has been reduced to solving a singular integral equation. For the numerical solution of this equation, the boundary element method has been used. The formulas for the effective numerical simulation of singular integrals with singularities of the Cauchy and Hadamard type have been obtained. The solution accuracy of the considered singular equation is investigated. Boundary elements with different density approximations are considered. It has been established that the use of boundary elements with a cubic approximation of density leads to a significant increase in the solution accuracy. Densities appearing as unknown functions in the considered integral equations are used to calculate stress intensity factors. Comparison of the analytical and numerical solutions of the considered singular equation, as well as the analytical and numerical values of the stress intensity coefficients has been performed. The initial crack length starting crack development has been determined by using the threshold value of the stress intensity factor. The critical number of loading cycles leading to cracks of an unacceptable size has been calculated based on the Paris criterion. This critical number of cycles is a characteristic of durability. To compare the durability characteristics, the problems of determining the critical number of cycles for plates with single isolated cracks and with crack chains are considered. It has been established that at the same loading level, the smallest critical number of cycles corresponds to a structural element with cracks in the vicinity of technological holes.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-43-08
The directed network of telephone subscribers is considered in the article. It can be described as a dynamic network with vertices that correspond to the subscribers of the telephone network and emerging directional edges that correspond to the connections between the respective subscribers. The position of the edge and its direction is determined by the incoming and outgoing calls from the corresponding vertices. The subject of the article is the statistical properties of the connections of a certain subset of telephone network subscribers. Such connections are dynamic in nature due to their appearance and disappearance. The number of outgoing (or incoming) connections occurred during a day at a selected vertex is used as the main characteristic. The distribution density of the number of outgoing (or incoming) connections (or calls) of such a network has been analyzed using the experimental data. It has been shown that such a distribution density over the number of calls obeys the lognormal distribution density, which depends on the two parameters. The values of two parameters, namely the mean value and the variance, determining the lognormal distribution density are established. The reasons for the appearance of a lognormal distribution density over the number of incoming (or outgoing) connections have been discussed. The statistical properties of other groups of subscribers have been considered as well. In particular, the group that makes a large number of outgoing calls to various subscribers of the telephone network has been selected for a separate study. The members of this group, who create and distribute spam can be called spammers. It has been shown that these groups, spammers for example, also obeys the lognormal distribution density over the number of calls but they are characterized by the different mean value and variance.
{"title":"Statistical properties of the telephone network","authors":"","doi":"10.26565/2304-6201-2019-43-08","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-43-08","url":null,"abstract":"The directed network of telephone subscribers is considered in the article. It can be described as a dynamic network with vertices that correspond to the subscribers of the telephone network and emerging directional edges that correspond to the connections between the respective subscribers. The position of the edge and its direction is determined by the incoming and outgoing calls from the corresponding vertices. The subject of the article is the statistical properties of the connections of a certain subset of telephone network subscribers. Such connections are dynamic in nature due to their appearance and disappearance. The number of outgoing (or incoming) connections occurred during a day at a selected vertex is used as the main characteristic. The distribution density of the number of outgoing (or incoming) connections (or calls) of such a network has been analyzed using the experimental data. It has been shown that such a distribution density over the number of calls obeys the lognormal distribution density, which depends on the two parameters. The values of two parameters, namely the mean value and the variance, determining the lognormal distribution density are established. The reasons for the appearance of a lognormal distribution density over the number of incoming (or outgoing) connections have been discussed. The statistical properties of other groups of subscribers have been considered as well. In particular, the group that makes a large number of outgoing calls to various subscribers of the telephone network has been selected for a separate study. The members of this group, who create and distribute spam can be called spammers. It has been shown that these groups, spammers for example, also obeys the lognormal distribution density over the number of calls but they are characterized by the different mean value and variance.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-42-05
V. Karazin
In this work explored evolution of software lifecycle models firstly to lightweight and then to agile software development methodologies, and factors that have led to a search for ways to improve approaches to software development. Also compared "outdated" development designing approaches with modern flexible and made conclusions whether the advantage of the latter over the firsts is absolute and whether or not they and only they should be used in practice or maybe older approaches still have their advantages and it is too early to exclude them.
{"title":"Application of Agile methodologies for software development","authors":"V. Karazin","doi":"10.26565/2304-6201-2019-42-05","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-42-05","url":null,"abstract":"In this work explored evolution of software lifecycle models firstly to lightweight and then to agile software development methodologies, and factors that have led to a search for ways to improve approaches to software development. Also compared \"outdated\" development designing approaches with modern flexible and made conclusions whether the advantage of the latter over the firsts is absolute and whether or not they and only they should be used in practice or maybe older approaches still have their advantages and it is too early to exclude them.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-44-02
N. Varlamova, V. Lazurik, N. G. Styervoedov
The conceptual model of the information processing system for psychophysical and psychophysiological researches has been developed. The hardware-software implementation of this system will allow us to diagnose a person's mental state on site or remotely, to identify person's professional suitability, to measure psychophysiological and cognitive characteristics, to store and process research information using the cloud service. The structure of the information processing system model is represented by UML diagrams. The detailed plan of the information processing system realization is presented.
{"title":"Model and hardware-software implementation of information processing system for psychophysical and psychophysiological researches","authors":"N. Varlamova, V. Lazurik, N. G. Styervoedov","doi":"10.26565/2304-6201-2019-44-02","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-44-02","url":null,"abstract":"The conceptual model of the information processing system for psychophysical and psychophysiological researches has been developed. The hardware-software implementation of this system will allow us to diagnose a person's mental state on site or remotely, to identify person's professional suitability, to measure psychophysiological and cognitive characteristics, to store and process research information using the cloud service. The structure of the information processing system model is represented by UML diagrams. The detailed plan of the information processing system realization is presented.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-44-08
Within the generalized prisoner's dilemma, the evolution of a population with a complete set of behavioral strategies limited only by memory depth has been examined. Evolution considers the pairing of strategies, in accordance with the iterated prisoner's dilemma. In doing so, each strategy interacts with each, including itself. Each subsequent generation of the population consistently loses the most profitable behavior strategies of the previous generation. Increasing population memory has been shown to be evolutionarily beneficial. The winners of evolutionary selection consistently are the agents with maximum memory. The concept of strategy complexity has been introduced. Collective variables are introduced to obtain the average of the family of strategies and their changes over time are studied. Strategies that succeed in natural selection have been shown to have maximum or near maximum complexity. An alternative evolution of a family of strategies limited only by memory depth is considered. In each generation, a strategy that maximizes the point of evolutionary benefits is removed from the family. Such an alternative evolution leads to significant changes in the family compared to the normal evolution. In some ways, alternative evolution maintains maximum memory depth and complexity even more than normal evolution. The main difference is the stationary strategies being absolute aggressive against each other. The stationary family is formed by the strategies being the most aggressive towards each other. Memory depth and complexity of strategies, as in normal evolution, are evolutionarily beneficial properties. The universal relation between the aggressiveness of the population and the number of points of evolutionary advantages that the strategy receives on average per turn is considered. On the whole, the universal link between average aggression and the number of strategy payoffs per turn is maintained.
{"title":"Alternative evolution of strategies with memory","authors":"","doi":"10.26565/2304-6201-2019-44-08","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-44-08","url":null,"abstract":"Within the generalized prisoner's dilemma, the evolution of a population with a complete set of behavioral strategies limited only by memory depth has been examined. Evolution considers the pairing of strategies, in accordance with the iterated prisoner's dilemma. In doing so, each strategy interacts with each, including itself. Each subsequent generation of the population consistently loses the most profitable behavior strategies of the previous generation. Increasing population memory has been shown to be evolutionarily beneficial. The winners of evolutionary selection consistently are the agents with maximum memory. The concept of strategy complexity has been introduced. Collective variables are introduced to obtain the average of the family of strategies and their changes over time are studied. Strategies that succeed in natural selection have been shown to have maximum or near maximum complexity. An alternative evolution of a family of strategies limited only by memory depth is considered. In each generation, a strategy that maximizes the point of evolutionary benefits is removed from the family. Such an alternative evolution leads to significant changes in the family compared to the normal evolution. In some ways, alternative evolution maintains maximum memory depth and complexity even more than normal evolution. The main difference is the stationary strategies being absolute aggressive against each other. The stationary family is formed by the strategies being the most aggressive towards each other. Memory depth and complexity of strategies, as in normal evolution, are evolutionarily beneficial properties. The universal relation between the aggressiveness of the population and the number of points of evolutionary advantages that the strategy receives on average per turn is considered. On the whole, the universal link between average aggression and the number of strategy payoffs per turn is maintained.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-42-02
D. G. Boguto, K. K. Kadomskiy, P. Nikolyuk, A. I. Pidgurska
Intersection is a basic element in the technology of urban traffic regulation. It is such object where city roads intersect and which is the main cause and source of congestion. Therefore, first of all, it is necessary to implement the intellectual regulation of vehicles movement through a separate intersection. Such regulation is carried out with a help of a computer program that takes into account the vehicle road situation at the intersection and the corresponding correction of the traffic lights signal phases. At a second stage it is necessary to plan an optimal route for each vehicle using, for example, A*-algorithm and the spectrum of data received from an infrastructure of the urban network. As a result of an application of these two phases of urban traffic regulation, an optimal movement regime of all city mobile transport is achieved. This work is practical and aimed at solving a specific problem – traffic problem in a big city.
{"title":"Algorithm of Intelligent Urban Traffic","authors":"D. G. Boguto, K. K. Kadomskiy, P. Nikolyuk, A. I. Pidgurska","doi":"10.26565/2304-6201-2019-42-02","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-42-02","url":null,"abstract":"Intersection is a basic element in the technology of urban traffic regulation. It is such object where city roads intersect and which is the main cause and source of congestion. Therefore, first of all, it is necessary to implement the intellectual regulation of vehicles movement through a separate intersection. Such regulation is carried out with a help of a computer program that takes into account the vehicle road situation at the intersection and the corresponding correction of the traffic lights signal phases. At a second stage it is necessary to plan an optimal route for each vehicle using, for example, A*-algorithm and the spectrum of data received from an infrastructure of the urban network. As a result of an application of these two phases of urban traffic regulation, an optimal movement regime of all city mobile transport is achieved. This work is practical and aimed at solving a specific problem – traffic problem in a big city.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-44-03
One of actual issues in the field of gas dynamics of piston engines which concerns the analytical estimation of influence of structural and regime parameters on the processes of flowing of gases through gas distribution mechanisms is examined. Gas interchange process in two-tact engines is performed by means of opening-closing of blow-off windows or slide-valve with a piston. The method of calculating the total plane of the flow area of slide-valve air distributor for a motor-car pneumatic engine is proposed. The mathematical descriptions of the pre-set areas of the entry and exit openings of slide-valve air distributor have been performed with the help of the theory of R-functions. The algorithm for creating the computer calculating program for determining the flow area of slide-valve air distributor is considered. The proposed algorithm has been used for developing the software application intended for calculating the areas which are formed by the entry and exit openings of slide-valve accounting for their different possible configurations. The calculations of flow area of these openings allow determining the air losses in the air distributive system of pneumatic engine and defining the specific size for the inlets and outlets of the compressed air. The results of calculations of the air distribution system and the parameters of the compressed air intake is presented as a separate block in the general dynamic model of calculations of working processes of the motor-car pneumatic engine, when determining the speed, temperature and air flow of the slide-valve air distributor. The motor-car pneumatic engine is more economical and environmentally friendly in comparison with the internal combustion engine at the low revolutions.
{"title":"Calculation of the total cross-sectional area of the spool air of the distributor of an automobile air motor","authors":"","doi":"10.26565/2304-6201-2019-44-03","DOIUrl":"https://doi.org/10.26565/2304-6201-2019-44-03","url":null,"abstract":"One of actual issues in the field of gas dynamics of piston engines which concerns the analytical estimation of influence of structural and regime parameters on the processes of flowing of gases through gas distribution mechanisms is examined. Gas interchange process in two-tact engines is performed by means of opening-closing of blow-off windows or slide-valve with a piston. The method of calculating the total plane of the flow area of slide-valve air distributor for a motor-car pneumatic engine is proposed. The mathematical descriptions of the pre-set areas of the entry and exit openings of slide-valve air distributor have been performed with the help of the theory of R-functions. The algorithm for creating the computer calculating program for determining the flow area of slide-valve air distributor is considered. The proposed algorithm has been used for developing the software application intended for calculating the areas which are formed by the entry and exit openings of slide-valve accounting for their different possible configurations. The calculations of flow area of these openings allow determining the air losses in the air distributive system of pneumatic engine and defining the specific size for the inlets and outlets of the compressed air. The results of calculations of the air distribution system and the parameters of the compressed air intake is presented as a separate block in the general dynamic model of calculations of working processes of the motor-car pneumatic engine, when determining the speed, temperature and air flow of the slide-valve air distributor. The motor-car pneumatic engine is more economical and environmentally friendly in comparison with the internal combustion engine at the low revolutions.","PeriodicalId":33695,"journal":{"name":"Visnik Kharkivs''kogo natsional''nogo universitetu imeni VN Karazina Seriia Matematichne modeliuvannia informatsiini tekhnologiyi avtomatizovani sistemi upravlinnia","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69003428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.26565/2304-6201-2019-42-03
The article describes the payback calculation system of introduction a network solar power plants in private households that are locating in Ukraine. The system takes into account such parameters as beam, ground-reflected and diffuse solar radiation with atmospheric attenuation, the angle and the orientation roof, the daily average temperature of photovoltaic cells and the temperature coefficient of solar panels, when calculating the generation of a network solar power plant. The flux of solar radiation that falls on the surface of the photovoltaic cells is determined of the Hay-Davis model. When calculating the payback solar power plant takes into account such parameters as annual electricity consumption, current electricity price, feed-in tariff and annual electricity price increase. The average market price of a network solar power plant is taken at the rate of 1 dollar per 1 watt of installed capacity. Based on these parameters, the system calculates a monthly, daily average and annual generation of a network solar power plant, calculates the relative cost of a network solar power plant, calculates of electricity costs forecast over twenty years and calculates a payback period of a network solar power plant. The monthly and daily average generation of a network solar power plant, electricity costs forecast over twenty years and payback period of a network solar power plant displayed in the system in the form of corresponding graphs and diagrams. In the case if investments necessary for the construction and commissioning of a network solar power plant don’t pay off within twenty years, the system will display this information in the corresponding field.
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