Graphic-analytical Method Research Articles

Methods for synthesis of matching circuits for broadband radio devices with unstable load impedance

The aim of this work is to select a synthesis method for a broadband matching circuit that provides maximum power transfer from a signal source to a load in the presence of a changing load impedance of a radio engineering device. To achieve this goal, an analysis of the main directions of designing broadband matching circuits (analytical, numerical, graphic-analytical synthesis methods) was carried out. Based on the results of a comparison of synthesis methods, their features (advantages and disadvantages) were indicated. The analysis of methods of synthesis of broadband matching circuits was carried out. For the analysis, the generalized Darlington method, the method of real frequencies, the structural-parametric synthesis method based on the T-matrix apparatus, and the graphic-analytical method based on the Volpert-Smith diagram were chosen). Using these synthesis methods, broadband matching circuits were obtained for various types of loads. Comparison of the results obtained was carried out according to several indicators: the level of the power transfer coefficient in the operating frequency range, the sensitivity of the power transfer coefficient to the change in the ratings of the elements of the matching circuit and the load impedance, provided that the number of elements of the matching circuit is no more than six. Based on the comparison and analysis, it was found that the most preferable synthesis method for solving the problem posed is the method of real frequencies. Its advantage is the use of a combination approach (iterative determination of the parameters of the resistance function with an analytical representation of the transfer function). Matching circuits obtained using this synthesis method provided the highest level of power transmission coefficient, as well as the lowest sensitivity value in a given frequency band for the considered types of loads.

LEADERSHIP POTENTIAL IMPACT ON PERFORMANCE OF SMALL AND MEDIUM-SIZES BUSINESS

Small and medium-sized business (SMB) as a special type of economic activity and one of the levers of the national economy functioning is being recognized by leading economies as a key form of business. However, in most cases, the development of SMB depends on the features of government support and tax preferences. At the same time, human resources are considered to be the most valuable assets in meeting the economic challenges. Therefore, the current study dwells on the ways for SMB to overcome the challenges utilizing human resources leadership potential development since human resources determine either integral or inconsistent nature of any business activity. The current paper presents the research results on the leadership potential development and its impact on the performance of SMB.
 On top of that the authors have determined some indicators to measure leadership potential of the country’s economy and establish the correlation between the SMB development index, the ease of doing business index, and the human development index.
 The methodological foundation of the research is a system of general scientific and special methods applied to investigate the impact of leadership potential phenomenon on the performance of small and medium-sized enterprises. The following methods have particularly been applied: the general method of comparing followed by generalization — to specify and formalize the essence of the concept; correlation and regression analysis — to build multifactorial regression models, to calculate the predictable characteristics of leadership potential integral indicators for each subsystem, to determine the degree of leadership potential influence on the performance of SMB; the graphical-analytical method — to provide visual clarity of the material and schematic representation of some theoretical and practical provisions of the current study. In order to perform the complex analysis of the research results, the computer-aided data processing methods have been applied, performed via Microsoft Excel, STATISTICA software. The statistical materials of the State Statistics Service of Ukraine, official publications of international organizations, expert evaluations of rating agencies, monographs, fundamental scientific developments of Ukrainian and foreign authors, materials of scientific conferences, national and foreign publications, electronic resources on the Internet have been the information database of the current study [7—10].

О влиянии почвенных и технологических условий на параметры зон увлажнения почвы, формируемых при капельном поливе древесно-плодовых культур

Purpose: development of a graphic-analytical method for assessing the effect of soil conditions on moisture contours size formed during drip irrigation to select the parameters of drip modules for irrigating tree-fruit plants cultivated in garden plantations. Materials and methods: the planned dimensions of moisture contours of sub-drip soil space are taken as indicators for assessing and determining the parameters of irrigation modules for drip irrigation of row planted tree-fruit crops from along-row traced irrigation pipelines. When analyzing the parameters and location of moisture zones, the layout of plants in a garden with a distance between trees in a row equal to 2 m was considered, with a different number of drip emitters on the drip line within the inter-tree area. Results: using the author's dependence, the diameters and areas of moisture contours formed during drip irrigation in southern medium-thick chernozems were determined. For typical schemes for placing drip emitters along a row of traced drip lines that provide soil moistening in the undercrown space of fruit plants, moisture contours formed during drip irrigation are built. The obtained geometric parameters of moisture zones for different patterns of irrigation lines, characterized by different inter-emitters distances and different numbers and locations of drip emitters, are compared with the area of plant nutrition. Based on the results of comparing the areas of moisture zone and the zone of plant root systems distribution, a high degree of locality of the wetted space was noted. Conclusions: the graphic images and quantitative characteristics of drip moisture zones in the undercrown along the row space of plants created using the proposed graphic-analytical method allow assessing the state of its moisture content and making a decision on the parameters and schemes of the irrigation module for certain soil and technological conditions of the garden plantation.

The Role of International Cooperation in the Process of Reforming the Higher Education System of Ukraine

The main purpose of this research work is to substantiate the need for international cooperation of Ukrainian higher education institutions as an important factor in reforming and modernizing the national education system, its successful integration into the global educational space and increasing competitiveness in the market of educational services. The basic method in the study is system approach. Methods of scientific abstraction, analysis and synthesis are used to form a theoretical synthesis and conclusions, graphic-analytical method is used for a clear illustration of the economic phenomena and processes under study. Internationalization of higher education is one of the main directions of the new conception of higher education reform in Ukraine. New demands and needs in the market of educational services, growing competition between higher education institutions, implementation of innovations in the educational process require changes in approaches to reform in the field of higher education in order to improve quality. International cooperation in the State University of Infrastructure and Technologies is considered as a process of formation and development of equal and mutually beneficial partnerships between educational institutions of different countries. International cooperation will give the State University of Infrastructure and Technologies the opportunity to participate in international projects in an equal and full manner, increase the number of foreign students, invite foreign lecturers to become a fully recognized university in the world, which provides high quality education.

ЭВОЛЮЦИЯ И СОЦИОКУЛЬТУРНАЯ ЗНАЧИМОСТЬ «ЗЕЛЕНЫХ» ОБЩЕСТВЕННЫХ ПРОСТРАНСТВ КРАСНОЯРСКА

One of the criteria for a comfortable ecologically clean urban environment is access to green spaces, their number and quality in any given city. Public green spaces play an important socio-cultural role in the context of active and passive recreation of citizens, various types of recreational activities. The relevance of this study is due to increased attention to the formation of open public spaces in the city of Krasnoyarsk. The purpose of this work is to trace the evolution and identify the social and cultural significance of the green public spaces in Krasnoyarsk. The objectives of the research are to study the green spaces of Krasnoyarsk in a historical retrospective, analyze the green spaces of Krasnoyarsk from the point of view of their ecological significance, recreational use. Research methods included literature review on the topic, analysis of historical data, field survey of the territory, long-term observation, photographic recording, comparative retrospective analysis, and graphic-analytical method. The study captures the most common types of public green spaces and their role in creating a comfortable urban environment. It traces in the most detail the evolution and cultural significance of the most important historical green spaces in Krasnoyarsk: the City Garden (now the Central Park), Yudinsky Garden, Krutovsky Garden. These examples show that gardens and parks can be formed both on the basis of the natural environment of urban forests, and artificially created by the efforts of citizens, that over time they can undergo various quantitative and qualitative, planning and functional transformations. Despite the transformations that have taken place, all the studied historical objects still exist and are used for their intended purpose. In addition to these historical green areas, we examine the newly organized public green spaces with a cultural and recreational component over the past decades: Tatyshev Park, All-season Fun-Park Bobrovy Log, Flora and Fauna Park Roev Ruchey, Dream Gardens and others. The article notes the importance of municipal, public and private initiatives in the organization of local green areas. The analysis allows us to assert that there is a certain system of public green spaces in Krasnoyarsk. It has disadvantages, such as an uneven distribution of green areas throughout the city, lack of interconnections between individual elements, aging of certain areas of greenery, and the complete destruction of some. Nevertheless, the city authorities, architects, designers and the general public make great effort to create a green framework for Krasnoyarsk destined to have an important recreational and cultural role.

To the mathematical model of the process of contact heating of seeds in vacuum

Annotation Purpose. To increase the degree of adequacy of the mathematical model of contact heating of seeds in a vacuum due to the refinement of the overall coefficient of thermal conductivity. Methods. The study of the mathematical model of the process of contact heating of seeds in vacuum was carried out using the methods of optical physics, planimetry, thermal physics. Mathematical dependencies were developed using algebraic transformations. The analysis of the obtained mathematical dependencies was carried out by the methods of technical analysis and graphic-analytical methods by comparing the graphs of the seed heating kinetics. Results. The total heat flow in the vacuum chamber, which exits the heating surface and is divided into two flows, has been studied, one of them transfers heat due to heat conduction through the touch of seeds with a heating surface and between themselves, and the second transfers heat through radiation in the cavities between the seeds. Calculation formulas for these heat fluxes have been developed, through which the formula for calculating the total thermal conductivity coefficient has been determined. This formula shows that the overall thermal conductivity is less than the theoretical value and depends on the equivalent seed diameter and seed characteristics. Conclusions. It has been established that the total thermal conductivity coefficient of seeds is less than the theoretical one due to voids between seeds, in which the heat of less heated layers propagates through radiation. The loss of thermal energy in the voids between the seeds increase the duration of the heating process and depend on the equivalent diameter of the seeds, the degree of blackness and the difference between the initial temperatures of the seeds and the heating surface. Keywords: seeds, contact heating, seed temperature, thermal conductivity, radiation, heat flux, heating surface, equivalent diameter, space between seeds.

Carrying out an experiment of face milling of hardened steel 95X18-Sh and the calculation of effective cutting modes of a given flatness by the graphic-analytical method

Carrying out an experiment of face milling of hardened steel 95X18-Sh and the calculation of effective cutting modes of a given flatness by the graphic-analytical method

Thermal fluctuation constants of PVC elements of different cross-sections

Consideration of the durability of building materials from a thermal fluctuation position is the most difficult, but at the same time the most adequate method now. Since this concept is insensitive to changes in the physical structure, it becomes necessary to consider not only the material, but also the configuration of the structure. This will make it possible to bring the simplified theoretical ideas about the performance of a building material in a structure closer to real conditions. Thus, the aim of the work is to compare the destruction mechanism of PVC sheet elements of solid section and composite section from the thermal fluctuation position. To achieve this goal, the initial data for finding thermal fluctuation constants (durability of PVC plates at non-critical stress) were determined by an experimental method. Based on the initial data, the thermal fluctuation constants for each section were determined by the graphic-analytical method. During the comparative analysis, it is proposed to introduce a coefficient into the Zhurkov’s equation, which will consider the configuration of the section. It was also determined that for PVC sheet elements of composite cross-section in two layers, this coefficient is kc = 2. Considering the configuration of the cross-section when determining the thermal fluctuation dependences will increase the quality of predicting the durability of the building material.

Substantiation of the technological scheme of development of the outstripping overburden bench at quarry field curvilinear contour

The porpoise of the research is to develop technological schemes of overburden rocks extraction on the outstripping overburden bench with a further rational scheme choice in the curvilinear quarry contour conditions. Research methods – theoretical and experimental; graphic-analytical method; method of statistical and system analysis; method of technical and economic analysis for the selection of effective technological schemes for stripping operations. Research results. As a result of the research, possible options for the development of the outstrippingoverburden bench were considered. A comparative technical and economic assessment of possible options for the mining operations progress, taking into account the change in the length of the mining operations front, has been carried out. The selection and justification of the technological scheme for the outstripping overburden bench development with a rotary complex using a KU-800 excavator at the Motronivsky GOK quarry for the period of the mining operations front in the northern part of the quarry field has been performed. Scientific novelty. Possible directions of ensuring the required productivity of stripping operations on the outstripping ledge are proposed. The ratio of the prime cost of overburden development for the studied technological schemes has been established. The choice of a rational technological scheme with the lowest cost of stripping works has been made. Practical value. The performed research allow us to choose a rational scheme for performing stripping mining operations, taking into account the curvilinear contour of the quarry field and ensuring the required performance of stripping operations by ensuring the necessary advancement of the mining operation front on the above-ore and middle stripping benches. The expected technical and economic effect is expressed in a reduction in the overburden development cost due to the use of an efficient mining complex and a technological scheme for the overburden development.

Slopes stability analysis from Rosia Poieni open pit mine, Romania

In the case of Roşia Poieni open pit mine the level of +805 m was established as a daily operating limit; the division into benches was based on this level by dividing into horizontal slices with a thickness of 15 m, equal to the height of the bench. Thus, there were 27 benches in the Curmătura area and 23 benches in the Ruginiş area. The general slope angle was set at 35°, the angle for which the tailings volumes and implicitly the opening-up coefficient were calculated. The stability analysis was performed for individual bench, 2 benches system and the general slope of the quarry (consisting of 24 benches), using two methods (Fellenius and Janbu). A polygonal slip surface was also modelled; such potential landslide surfaces can appear in the slopes of the Roşia Poieni quarry due to the natural cracking systems of the massif but also due to the secondary cracking generated by the used drilling-blasting works (exploitation technology). The stability check was done by applying Hoek’s graphical-analytical method; the determined values for the safety factor satisfy the condition of being greater than 1.3. In these circumstances, no further measures are required to increase the stability reserve.

Интерпретация опытно-фильтрационных работ из несовершенных скважин в слабопроницаемом скальном массиве с учетом потока в стволе совершенной наблюдательной скважины на примере участка «Енисейский»

The paper presents the processing of 2 cluster pumpings from imperfect wells inside a low-permeable rock mass. The processing was done using graphical-analytical method with three-dimensional modeling in GMS 10.4 software. The results obtained were analyzed and the interpretation methods of groundwater inflow testing (GIT) were compared. The paper identifies common patterns in the model GIT interpretation with some assumptions made on how to improve the processing of their results.

Calculation of water hammer on the pressure pipeline of modernized irrigation pumping station

One of the main factors to provide reliable and safe operation of irrigation pump station – prevent possible occurrence of water hammer. In order to determine the magnitude of water hammer’s method of characteristics (moc), wave characteristic method (wcm), graphical analytical and simplified methods of calculations are used. During the design for the construction of the new pump station surge analysis should be carried out using accurate calculation methods moc or wcm using special computer software. At the same time, should the modernization of existing pump station is taking place with the installation of the same equipment, then simplified calculations method can be used. But care must be taken to take in to account all the factors that might increase the risk of occurrence and with the higher magnitude of water hammer: reduced inertia of pumping set’s moving parts, replacement of shutting valves to different types, replacement of air valves to different types, reduction of hydraulic losses after discharge pipeline repair works and etc. Existing simplified calculation methods to calculate water transients in pump stations was modified to take in to account these factors. Based on the proposed method surge analysis calculations had been carried out at modernized pump station “Kizil-tepa”. Comparison of calculation results performed by simplified method and wcm using «KY-Pipe 2018-Surge program-version 9.014» has shown a good similarity in the magnitude of maximal positive pressures.

Development of the methods of kinematic analysis of elliptic drum of vertical-spindle cotton harvester

The paper is devoted to the development of a graphic-analytical method for studying the lever mechanism of an elliptical drum of a cotton harvester, which favorably differs from a serial drum in the completeness of cotton picking from bushes and the quality of the harvested raw cotton. The aim of the study is to define the degree of the effect of the structure and geometry of individual links of the elliptical drum mechanism on changes in kinematic parameters of the characteristic points of the mechanism links, in particular, of the spindles centers. The kinematics of the mechanism was investigated using classical methods of theoretical mechanics, the theory of mechanisms and mechanics of machines, combined with modern methods of computer graphics. The developed research method was described, its usefulness and advantages were shown. As an example, computational and graphic procedures were performed to determine the linear and angular velocities and accelerations of the characteristic points of the mechanism of an elliptical drum in its specific position. The method is clear, easy to control the results, allows one to quickly solve applied design problems, and develops an engineering intuition to evaluate the capabilities of the mechanism according to its kinematic scheme. The research results are of interest for a wide practical application of elliptical spindle drums in the construction of vertical-spindle cotton harvesters.

Solution of the problem of recultivation of sludge sites at the oil fields by electroosmosis

The problem of reclamation of sludge pits in oil fields is still being solved using the resource-intensive method. An accelerated technology of sludge dewatering by electroosmotic action is proposed. The concept of specific energy consumption for mass transfer is introduced. To eliminate the influence of relaxation of gradient fields, it is proposed to change the parameters of electrical energy. A graphic-analytical method for selecting the power of an energy source is proposed. The article shows that electroosmosis can be the optimal physical process for dewatering drill cuttings. To reduce the time of the process of reclamation of sludge pits, it is advisable to eliminate the relaxation of various force gradient fields by changing the parameters of the electricity supplied to the electrodes. Recommendations are given that the technological cycle of reclamation should be carried out in one summer season, during which, using electroosmosis, reduce the moisture content of the sludge and the concentration of chemical pollutants to an acceptable level, and then sow the barn with plants and thereby return the area to normal use.

Experimental Study of the Distribution of Temperature Fields in the Butt Contour of a Welded Joint Made of Carbon and High-Alloy Structural Steels

A graphic-analytical method for determining temperature fields in the butt contour of a welded joint of a thin-walled tube with a base is presented. The method is based on the experimental data of temperature measurement at the reference points of the structure. The features of the elements of the welded joint made of carbon and high-alloy structural steels and the modes of electric arc welding were taken into account. A graphic-analytical method for determining temperature fields is proposed, which, on the basis of the theory of welding strains and stresses, makes it possible to determine temperature stresses and strains, both in the elements of the joint and in the contour of the weld.

Optimization of the Process of Unloading of Iron Ore Raw Materials: The Case of a Steel Plant

The process of unloading iron ore raw materials of the metallurgical plant to the sinter plant has not been considered for a long time as a particular topic. Over the last years the conditions of metallurgical production have undergone certain changes: its intensification has occurred, which entails the need to re-evaluate parameters of stable operation of sinter production. The objective of the suggested study is to consider the issues of possible technical and technological improvement harmonizing transport flows with the requirements of the main production process. To achieve this goal, a technique of mathematical modelling is used, based on the mathematical apparatus of linear programming; graphic-analytical method; method of probability theory.The issues of the process of unloading, storage of iron ore raw materials, of their preparation for sinter production are primarily considered.The article presents the main positions of the process of optimizing unloading of sinter batch of a metallurgical plant.The general characteristics of the technology of metallurgical production and of each particular process are described. The agglomeration process is considered in more detail. The tables of initial iron ore raw materials for sintering production for certain reporting periods are given, for the sake of clarity, the data of one of the tables are summarized in a diagram. A diagram of a standard trestle-type ore warehouse is considered, which sequentially shows the main processes of sintering production from supply of raw materials to the car dumper to getting through a belt conveyor into a stack, and then into receiving bins. The article also provides an example of formation of piles of iron ore raw materials using manganese limestone.The study is based on a dynamic transport problem with delays (DTPD), which considers time of transportation of goods, the dynamics of production volumes over time, the dynamics of consumption, the dynamics of stocks of suppliers and consumers, dynamics of cost of transportation and storage, dynamics of cost of consumption losses. The study contains several mono-problems with a mono load, which overlap each other, forming a multiplicative overlay of single-product problems.

Оптимальне керування рухом трактора

Goal of the study. Assessment of the possibility of optimizing tractor control by methods of automatic search for the optimum point. To achieve this goal, you must complete the following tasks: – to analyze the operating conditions of the tractor unit with the determination of the force factors affecting its operating conditions; – to develop a scheme and algorithm for the operation of the extreme regulator and analyze its functioning. Research methods. Analytical studies are based on methods of optimization of power factors acting on a tractor. The results of the study. An automatic regulator is considered, which provides an optimal ratio of the engine speed and the transmission gear ratio for each speed. The logic device generates a signal to change the power train ratio. The required travel speed of the tractor unit is set by the operator using the speed regulator. Changing the gear ratio changes the speed of the tractor. The signal of the deviation of the speed of movement, after amplification, provides an effect on the fuel supply and, by changing the revolutions of the crankshaft of the engine, brings the actual speed of the tractor to the set one. In the control system, the measurement of the amount of fuel consumed by the engine is carried out by a flow meter, and the measurement is carried out at certain intervals, and the current value is compared with the previous one. Reducing fuel consumption means that the influence on the change in gear ratio has been chosen in the right direction. Conclusions. The paper proposes a self-adjusting system. In a theoretical study of the possibility of optimal control of the tractor movement, equations are determined that are easily solved by the graphical analytical method. The graphical plotting determines the time the system reaches the optimal mode. The considered example of regulation of the power drive and the tractor engine does not exhaust the scope of application of self-adjusting systems. The operating modes of a number of units, as well as some interrelationships of design parameters, have static characteristics that ensure widespread use of these systems.

HOUSING POLICY OF A BIG CITY: SOCIO-PSYCHOLOGICAL CONDITIONS AND REQUIREMENTS (RESEARCH ON THE EXAMPLE OF IVANO-FRANKIVSK)

Abstract. This article is devoted to the study of the topical problem of qualitative accounting of socio-psychological conditions of human life in residential architecture, namely in the policy of forming the urban environment. The task of this study can be realized by analyzing the regulatory framework, namely, strategies for the socio-economic and spatial development of cities in parts related to housing construction, housing and communal policy, general planning and territorial principles of city development. Systematization and comparison of this information made it possible to single out the factors influencing the formation of design solutions and development in the city. Another important link in this study is the systematization of factors influencing the solution of the problems of forming a living environment. The aim of this study is to characterize the impact of socio-psychological requirements for environmental comfort in the context of housing policy in large cities. In accordance with the purpose of the study, the following tasks were formed: to streamline the system of socio-psychological factors and methods of their accounting in substantiating the housing policy of urban space; to analyze the socio-economic and spatial development strategies of the city of Ivano-Frankivsk for the last 5 years and sectoral documents of the architectural and construction sector and housing policy; to highlight the factors that underlie the formation of housing policy in Ivano-Frankivsk, to develop recommendations for taking into account the psychological aspects of society in the formation of housing policy in cities. The materials of this study are the aging of the socio-economic and spatial development of Ivano-Frankivsk for the last 5 years, as well as industry documents where the prospects for the development of the housing industry and housing policy are formed. The source base of the study to characterize the factors influencing the formation of the city's residential policy are scientific works on psychology, sociology, architectural sociology and public administration. The main research methods of this article are the method of factorial comparison. The methods of group comparison, and the graphical-analytical method of creating a structural model of factors and determining the place, as well as the role of socio-psychological factors in this model, were also used.

Comparative analysis of thermofluctuation constants of polyvinyl chloride plates obtained in various ways

To reliably predict efficiency of solids, it is necessary to know the values of their thermofluctuation constants, which are determined by experimentally obtained data using graphical, graphoanalytical, and mathematical methods. Using the same initial data, the thermal fluctuation constants were determined by different methods. The graphical method is presented by calculation using graphs built on graph paper. The graphic-analytical method uses MS Excel. The mathematical method operates directly with equations instead of a graphical representation. It is shown that the chosen method of obtaining the constants has a significant effect on the final result. It is recommended to use a mathematical method when determining the thermal fluctuation constants.

Theoretical Investigation of a Long Period Grating Sensor Employing Multilayer Fiber Geometry

A theoretical formulation of the long-period grating sensor is implemented with respect to efficient refractive indices of core and cladding. The obtained result is utilized further for determination of ERIs of core and cladding using graphical analytical method and multilayer fiber geometry. ERI values of primary guided core, bi and tri layer fiber geometry using MATLAB software. In the present paper effective refractive index of core and cladding for the two and three layers have been investigated. The cladding modes have also been calculated using Erdogan’s proposed three-layer geometry as well as two-layer graphical solution method. We have compared both the techniques, discussed the limitations of graphical solution method and the benefits of three-layer geometry.