A study of mixer-feeder equipment operational reliability

The article examines key aspects of reliability and justification of the frequency of replacement of air filters in internal combustion engines. The optimal air filter replacement interval is critical for ensuring efficient engine operation and reducing wear on parts, minimizing fuel costs, and optimizing the efficiency of mobile energy resources. The purpose of this article is to analyze the factors that affect the reliability of engine air filters and to justify the optimal replacement interval based on statistical analysis. Research methods are considered, including laboratory and operational tests and the collection of statistical information. The limit state of the engine air filter is assessed based on a set of direct and indirect signs. The results of the replacement frequency of air filters in Mazda cars are presented with their statistical processing. Calculations have established the following indicators for the replacement frequency of engine air filters: the average replacement frequency is 10.1 thousand km; the standard deviation of the average replacement frequency is 2.99 thousand km; the coefficient of variation is 0.44; the shift in the beginning of the dispersion of the average replacement frequency is 3.25 thousand km. The confidence interval limits for the average frequency of engine air filter replacement for the normal distribution law have been established: 6.03 thousand km – lower confidence limit; 14.17 thousand km – upper confidence limit. The conclusions emphasize the importance of a comprehensive approach to determining the frequency of replacement of engine air filters, taking into account operating conditions, the quality of filter elements, and the manufacturer's plant. To achieve efficiency in use and savings in maintenance and repair costs, it is recommended to take into account the actual operating conditions of mobile power equipment and the technical condition of the filters.

The problem of estimating the number of summands of random variables for a total normal distribution law or a sample average with a normal distribution is investigated. The Central limit theorem allows us to solve many complex applied problems using the developed mathematical apparatus of the normal probability distribution. Otherwise, we would have to operate with convolutions of distributions that are explicitly calculated in rare cases. The purpose of this paper is to theoretically estimate the number of terms of the Central limit theorem necessary for the sum or sample average to have a normal probability distribution law. The article proves two theorems and two consequences of them. The method of characteristic functions is used to prove theorems. The first theorem States the conditions under which the average sample of independent terms will have a normal distribution law with a given accuracy. The corollary of the first theorem determines the normal distribution for the sum of independent random variables under the conditions of theorem 1. The second theorem defines the normal distribution conditions for the average sample of independent random variables whose mathematical expectations fall in the same interval, and whose variances also fall in the same interval. The corollary of the second theorem determines the normal distribution for the sum of independent random variables under the conditions of theorem 2. According to the formula relations proved in theorem 1, a table of the required number of terms in the Central limit theorem is calculated to ensure the specified accuracy of approximation of the distribution of the values of the sample average to the normal distribution law. A graph of this dependence is constructed. The dependence is well approximated by a polynomial of the sixth degree. The relations and proved theorems obtained in the article are simple, from the point of view of calculations, and allow controlling the testing process for evaluating students ' knowledge. They make it possible to determine the number of experts when making collective decisions in the economy and organizational management systems, to conduct optimal selective quality control of products, to carry out the necessary number of observations and reasonable diagnostics in medicine.

The limit measurement errors in the geodesy are determining for the normal distribution law, But the errors, exceeding the limits are throw aside and accidental errors are obey the cut law. Cut laws are not study enough. The article is leading the results of calculate the probabilities hit accidental measurements errors for intervals σ, 2σ, 2,5σ, 3σ for cut normal and cut logical distribution laws. The analysis was accomplished.The probabilities of the cut normal and normal laws is different immaterial. 0,043 - maximum of the different. The normal law replace to the cut normal law is not recommending. Probabilities of the cut law may to use, when it is allowing to avoid the repetition of the field measurements.

The paper analyzes the homogeneity of the stochastic structure of the samples of oil flax fibres of the Ukrainian and Polish selections. The distribution laws of fibres as mixtures of the normal and logarithmically normal distribution laws are identified. The general probability distribution law of fibre lengths of oil flax of the Ukrainian selection is a mixture of four logarithmically normal laws of distribution, and the general probability distribution law of fibre lengths of oil flax of the Polish selection is a mixture of a normal distribution law and three logarithmically normal laws of distribution. The parameters of the relevant components of the common distribution laws are found as a result of solving the problem of nonlinear optimization using the method of generalized lowering gradient that is implemented in Excel tabular processor. The adequacy of the built nonlinear models of the distribution laws is proved by estimating the value of the determination index. The comparative analysis of distribution laws of general totalities, from which the oil flax fibre samples of the Ukrainian and Polish selections are obtained, is conducted by the Kolmogorov-Smirnov statistical criterion. This criterion allows us to test and reject the hypothesis about belonging of two independent samples to the same general totality. The analysis of the general distribution laws shows that the oil flax fibres of the Ukrainian selection have a more pronounced tendency to stratification by a fibre length. Such a fibre is easily divided into factions. The oil flax fibres of the Polish selection have a larger part of short and extra-long fibres. Thus, it is clear that raw materials of the Ukrainian selection are more suitable for the production of non-woven materials of different target purposes, and the Polish selection - for the production of ropes, cords, etc. The obtained results can be used by specialists at processing enterprises for a reasonable choice of raw materials, optimization of processing modes and improving ready-made product quality.

The result of the long existence of legal restrictions on the agricultural land market in Ukraine was the formation of a specific leasehold system of land use. Agricultural enterprises and farms do not have land owned. Instead, the peasants who became owners of land during the distribution of collective farms, mostly do not process these parcels of land on their own, but also deprived of the right to alienate them (to sell, give, change). The study shows the development of leased land use of agricultural enterprises in Ukraine, which currently covers 16.8 million hectares of private land and about 1 million hectares of state-owned land. Since 2003, the civil law of Ukraine permitted to apply not only the lease of agricultural land, but also the emphyteusis right (the alienated right to use someone’s land for agricultural purposes), the process of transformation of lease into emphyteusis was started, especially in large agricultural holdings. The main advantages of emphyteusis as a substantive law and its attractiveness for agribusiness are considered. The suggestions on improving the legal regulation of land use under conditions of emphyteusis are given.

The article focuses on the relevance of the issues of formation and implementation of the intra-corporate policy of digitalization of marketing of agrarian enterprises. It was established that the aspects of digitization and realization of its potential directly in the segment of agricultural enterprises in Ukraine are still not sufficiently developed. Therefore, the purpose of the study is to improve the methodological and applied principles and provisions of identification and substantiation of directions for strengthening the digitalization of marketing of agricultural enterprises. The advantages of the formation and development of digital management systems at domestic enterprises in general, as well as directly in the field of digitalization of their marketing systems and complexes, are emphasized. Prospective directions of digitalization of marketing of agrarian enterprises are determined by the following components: (1) product policy, (2) price policy, (3) policy of promotion and stimulation of product sales, (4) policy of product positioning on the market. The problematic aspects of the formation of an environment of digital marketing of agricultural enterprises in Ukraine are reflected. The strategic stages of the policy of development and expansion of the priority directions of digital marketing of agrarian business entities have been determined. The system of structural blocks of the program of digitalization of agricultural enterprise marketing is substantiated, in particular - initial conditions, policy goal, goals and directions of regulation, globalization block, financial-resource and organizational-management support, monitoring and adjustment tools. The toolkit for monitoring the digitalization of marketing of agricultural enterprises has been defined, which involves taking into account the system of indicators in three groups: (1) development of the intra-corporate digital system, (2) digital modernization of business processes, (3) harmonization and convergence of intra-corporate digital systems into the global system of the digital economy of Ukraine and the EU.

The purpose of the article is to analyze correlation between production volume (V), labour factor (L) and capital factor (K) with further production volume forecasting of researched agricultural enterprises in Ukraine as well as their competitiveness in the European market. Methodology. The survey based on statistical data of State statistics service in Ukraine, Poland and accounting data of investigated enterprises during 2004-2013 years. Production volume and capital amount taken in monetary terms, labour factor is calculated in monetary terms using the average wage and the number of employees. Treatment of major production factors according to classical economic theory is generalized. Correlation of V, L and K factors are calculated using method of the least squares in production function evaluation. Production volume of enterprises A and B are forecasted with further evaluation of its reliability in the econometric program EViews 7. Results of the survey showed the dominant role of L factor over the K factor especially after world economic crisis 2008 in investigated agricultural enterprises of Ukraine. According to high determination coefficient, the influence of both factors on production volume is 85% for enterprise A and 95% for enterprise B. Production forecast shows the increase of its volume till 2020 in both enterprises with high probability according to forecast credibility indicator MAPE. Practical implications. Application of the results, in particular the ratio of production factors and forecast of production volume, will allow more effective use of production resources and better planning of production process taking into account market conditions. Value/originality. Production activity estimation and output forecast of investigated agricultural enterprises were used for competitiveness analysis of agricultural enterprises in Ukraine and Poland, which is important for European integration process of domestic economy.

The performed study is the result of collecting statistical data on failures of port transshipment and floating cranes. It is found that many accidents of components and parts of crane mechanisms can be associated with an erroneous determination of design loads. In order to increase the strength reliability, numerous field tests were carried out in river and sea ports under various modes of transshipment for different types of cargo. Tests have shown that operational loads are random in nature, and their laws of distribution over time of individual crane mechanisms can be approximated by truncated normal Gauss laws, accounting for which at the stage of new design developments, as shown by the practice of performing strength fatigue calculations, is not possible. In the article, in order to use the obtained laws at the design stage, it is proposed to replace the representation of operational loads with initial moments that are common to the entire crane mechanism, and transfer individual characteristics consideration such as stress concentration coefficients, fatigue curve parameters, operating time or test base, to subsequent stages of machine components development. For practical testing of the operational loads representation by the normal Gauss laws, a critical analysis of their initial moments, which makes it possible to identify inconsistencies in the representations of variable loads proposed for strength calculation, is given. For the corrected truncated normal load distribution law, the initial moments, the value of the order of which corresponds to the formulas structure used in calculating fatigue resistance at variable load amplitudes (in particular, under alternating loading modes), are determined. The presentation of corrected normal distribution laws with initial moments complements the normative documents used in practice when performing strength calculations under variable loading conditions, significantly simplifies calculations and makes it possible to take it into account at the stage of new design developments in accordance with the formulas established in the current normative documents.

Objective: Arterial stiffness is independent and clinically relevant prognostic biomarker, which can be measured by different techniques, including carotid-femoral Pulse wave velocity (cfPWV), Branchial-ankle PWV baPWV. The aim of this study is to investigate if there is an agreement between ankle-branchial and Carotid-femoral pulse wave velocity. Design and method: The carotid- femoral and Branchio-ankle Pulse wave velocity of 30 patients coming for routine clinical checkup of cardiovascular risk evaluation were measured with SphygmoCor CVSM (Atcor Medical, Australia) and WatchBP Office Vascular (Microlife, Widnau, Switzerland). The mean of left and right leg measurements was used for calculating baPWV, whereas the mean of two measurements on the right side (median for 3) was used for cfPWV. The Bland-Altman Analysis was used for finding the agreement between the two types of pulse wave velocities. Results: 30 patients (63% men, age 66.89 ± 12.75 years, BMI 25.73 ± 3.84 kg/m2, MBP 92.866 ± 10.13 mmHg). CfPWV was 9.80 ± 2.56 m/s and baPWV was 14.24± 2.37 m/s. cfPWV and baPWV were linearly correlated with each other (r = 0.598, p = 0.0005). Both were positively correlated with age (cfPWV: r = 0.6083, p = 0.0004; baPWV r = 0.4716, p = 0.0103). The two metrics showed significant bias (bias CI95% 4.836, 95.0% lower confidence limit 0.901, 95.0% upper confidence limit 8.77). Conclusions: In a population of individuals undergoing cardiovascular screening, a significant bias between Cf-PWV and Ba-PWV was found, in accordance with previous studies. cfPWV and baPWV are correlated each other and showed a similar correlation with age. Larger head-to-head studies are needed to explore differences in relationship with risk factors.

Gradual vascular access port or tunneled central venous catheter occlusion during total parenteral nutrition is a common complication of unknown etiology, usually unresponsive to treatment with urokinase, ethanol, or hydrochloric acid. After establishing safety with regard to catheter materials and efficacy in dissolving the occluding substance in vitro, we treated a total of 13 vascular access ports (10 patients) that had occluded gradually during "three-in-one" total parental nutrition by slow perfusion with 10 to 20 mL of 0.1 mmol/mL sodium hydroxide solution. We found a mean increase in flow (results are flow rates under gravity-dependent vascular access port inlet pressure of 1.5 kPa) from 37 microL/s (95% upper confidence limit, 45 microL/s) to 75 microL/s (95% lower confidence limit, 64 microL/s; p < .001). For normal use, a flow of 50 microL/s is sufficient. There were no side effects. Five vascular access ports remained in excellent function during a follow-up period of 9 months. The others had reocclusions, but the partial reocclusions could be treated successfully.

Silicon carbide black grinding powders 54CF180-F36, mass-produced at Volzhsky Abrasive Plant are studied. Powders are screened into fractions according to GOST R 52381. Measurement of a grain width of each fraction was carried out by means of a photome-tric method using specially developed software. For the vast majority of fractions the grain width follows the normal distribution law. The deviation of the grain width from the normal law can be observed at the frac-tions settled on the second sieve and the pallet. With decreasing the nominal mesh size of a pass sieve in each grit size the arithmetic mean of grain width of the main fraction decreases, dispersion reduces from the fraction settling on the second sieve to the fourth and increases at the fraction settling on the pallet. In case of the identical mesh size of a pass sieve the mean and dispersion of grain width fraction increase with grinding powder grit increase. For each grit size the functional dependences of the mean and dispersion of grain width fraction on a mesh size of a pass sieve are established.

Warning and prevention of natural emergencies is based on the analysis and forecasting of threats of emergency situations in the state. At the same time, the forecasting of natural emergencies should be aimed at regulating natural safety in the country, assessing the threats of emergencies and their prevention. Prevention of natural emergencies of various natures, minimization of their consequences is a component of creating safe conditions for the individual and society as a whole, an integral part of the state policy of national security of the country. Ensuring safety in emergency situations requires reliable functioning of the emergency response system adequate to the level and nature of threats. The effectiveness of planning and implementing measures to prevent natural emergencies is determined by the quality of forecasting the threats of their occurrence Since the processes of occurrence of natural emergencies are of a random nature, knowledge of the law of distribution of the random variable “number of emergencies” in the state on the basis of statistical data acquires importance. The article presents the results of checking the compliance of statistical data on natural emergencies in the state with the normal distribution law. Based on the processing and analysis of monitoring data for natural emergencies, a hypothesis was put forward about the normal law of distribution of the random variable the «number of natural emergencies» in the state in accordance with the available information. Pearson’s goodness-of-fit test was chosen to test the proposed hypotheses. An assessment was made in accordance with the chosen criterion of the hypothesis about the agreement of the sample distribution with the law of normal distribution. Asa result of the research, it was found that the hypothesis put forward does not contradict the statistical data of monitoring natural emergencies over a certain period of time. The parameters of the established distribution law were evaluated.

Introduction. Agriculture is a basic element of the Ukrainian economy, providing a significant part of GDP, the lion’s share of commodity exports, and to a large extent forming the resource base and credit portfolio of the banking system. At the same time, the active development of the agribusiness sector requires not only significant additional volumes of long-term and cheap credit resources in the national currency, but also additional specific banking products and services, which are currently offered by banks only fragmentarily. Problems Statement. The analysis of the main factors of activating bank lending and improving the mechanism of comprehensive banking services for agribusiness enterprises in Ukraine and substantiation of the list of measures taken by the state aimed at solving existing problems in this area. The purpose is the analysis of the main obstacles standing in the way of activating bank lending and improving the mechanism of banking services for agribusiness enterprises, substantiation of necessary measures by the state aimed at overcoming existing negative trends in the field of lending and banking services for farmers. Methods. General scientific and special methods are used: analysis, synthesis, grouping, description, comparison, theoretical generalization and abstract-logical. Results. Credit and other banking products aimed at agricultural producers and the main factors hindering the activation of lending to agricultural enterprises in Ukraine are analyzed. A range of measures aimed at solving existing problems is determined, including the expansion of the range of specific banking services at the level of one of the state banks with the subsequent creation of a specialized agricultural bank in the medium term. Recommendations for legislative support for this process are proposed. Conclusions. The agricultural sector forms a significant share of GDP and a significant part of Ukraine’s export revenues, and its further development requires active support from the banking system. This highlights the need for a set of measures by the state aimed at activating bank lending to agribusiness enterprises in the “single window” mode. To this end, it is advisable to recommend: amending the Regulation on determining the amount of credit risk for active banking operations by banks of Ukraine in terms of easing the requirements for liquidity ratios of real estate collateral; easing the requirements for agricultural sector enterprises regarding formal compliance with ESG standards of production projects that are financed within the framework of the government program “Affordable Loans 5-7-9%”; developing an expanded range of credit products and related specific banking services for farmers, organizing the provision of this package by one of the state-owned banks in the “single window” mode; developing a mechanism for long-term targeted refinancing of banks with the subsequent allocation of these funds to agricultural enterprises in the form of long-term loans; clarification and synchronization of contradictory provisions of the current legislation of Ukraine regarding banks and banking activities; determination of the feasibility of creating a specialized state agrobank, which should offer agribusiness enterprises a wide range of credit products and related services, introduce successful mortgage lending practices, contributing to the formation of a liquid land market, and should also become the main operator for attracting and distributing funds from foreign partners that will flow to Ukraine within the framework of the implementation of the Green Deal programs etc.

Актуальность темы исследования обусловлена тенденцией к применению постоянных магнитов в конструкциях электромеханических преобразователей, которая выражается в многополюсном исполнении синхронных магнитоэлектрических машин, работающих в генераторном и двигательном режимах [1, 2]. В статье представлено совершенствование методики идентификации постоянных магнитов, приведенной в [3] на основе исследования закона распределения магнитных сил взаимодействия между опытными образцами постоянных магнитов и магнитным отражателем на соответствие нормальному закону распределения по критерию согласия Пирсона. Показана возможность использования методов и свойств нормального закона распределения при решении вопроса идентификации постоянных магнитов с одинаковой объемной намагниченностью и выборки постоянных магнитов из опытной партии для разработки и создания магнитоэлектрических машин различного назначения.

In time series analysis, especially in non-linear time series, a school appeared after 1963. The classical school argued share price variations obey the normal distribution law and are random, in which case observations are identically distributed and independent. Although Brown (1828), Bachelier (1900), and Einstein (1905) created the background, the well-known AR(IMA) models were invented by Yule (1927). The modern school argued that time series appear to be random with a behavior under determinism, are subject to power law, and have a long run memory. Recent (nonlinear) work has not related to shipping freight derivatives, but to ship prices and freight markets. Derivatives are known as a shipping risk management means. According to the classical theory, derivative value should relate to volatility and reward, and volatility relates to standard deviation, provided the randomness of freight rates, for freight market risk management. That, to the shipping industry and its bankers, risk management is an alien concept, was written about by Stokes (1997). Stokes likened the typical shipowner to a speculator or a gambler who enjoys making large bets, and, in the hope of winning an enormous prize, risks liberal amounts of money. The authors' personal experience is that Greek shipowners, at least, are conservative. There are times when it is true, however, that in a three-year (ship) operation, more money comes from a single asset's sale than its use. Both tremendous failures and unbelievable fortunes have been created by the shipping industry, and the bankers pick up the pieces at day's end. People are attracted to the industry by massive successes, such as those seen in recent years, and repelled by failures. That risk must be managed is of no doubt, for it certainly exists. Understanding relevant market natures allow this best to be achieved. The authors demonstrate that shipping freight derivatives are persistent, while freight markets are anti-persistent, rather than random. Interaction between two opposing forces seems to occur through this phenomenon. Shipping freight market analysis must be done in a general finance context. Mandelbrot-Hudson (2004) approach applications suggests that a catastrophe's real chances of happening range between 1/10 and 1/30, or, in other words, it is much greater than what would be indicated by random walk.