This article discusses the general principles of developing software applications for generating and verifying practical tasks in mathematical disciplines in the Visual Basic for Application development environment. The structure of computer programs is described, the main components of the implemented macros are investigated, the algorithms of the basic procedures are given. A special place is given to the problems of identifying students and protecting the generated data. We have also given recommendations on the use of developed programs in the educational process

The purpose of this work is to study the effect of clock synchronization of reference generators of special communication systems on the retention of the frame synchronization of PSP sensors when switching them to the deceleration mode, as well as short interruptions in operation, for example, when power surges, etc. in terms of electronic suppression

One of the most important problems facing agricultural production is to increase traction and energy properties and to decrease the deforming effect of wheel propellers of power tractors on the soil. The solution to this problem requires the widespread introduction of computer-aided design systems, which make it possible to predict the towing, fuel, economic, and agro-technological properties of the tractor unit at the design stage. Traction and energy indicators of wheeled agricultural tractors, the level of impact of wheel propellers on the soil are largely determined by the quality of pneumatic tires. The search for the optimal parameters of pneumatic tires, the compliance of tire characteristics with the parameters and operating conditions of the tractor unit, require solving two main problems. Firstly, the development of analytical dependencies describing the process of interaction of elastic wheels with the soil base, depending on the rolling mode of the wheel. Secondly, bringing to the engineering level the methods of calculation and analysis of the wheel propellers and soil system. The work discusses the issues of physical and mathematical modeling of a pneumatic wheel and soil system. It is noted that among the existing approaches to describing the process of interaction of an elastic wheel with soil, it is most preferable to use rheological models that take into account the simultaneous deformation and subsequent restoration of the soil and tire. However, when it comes to the existing models, the formation of the area of the contact patch is associated with a common normal deflection, which is not confirmed by numerous experimental studies. In the present work, the concept of agrotechnological deflection of a pneumatic tire is introduced. The developed model makes it possible to calculate the rut dept, the tangential and radial deformations of the tire, the longitudinal and normal deformations of the base, and the contact pressure under a known normal load on the wheel, wheel rolling radius and speed. We have also presented analytical and experimental dependences of the contact pressure and the rut depth on the size of the agrotechnical deflection

Enhancing the operative parts of a threshing mechanism which are realizing direct mechanical impact on an ear and being in it grains it is impossible to achieve the considerable lowering and to completely exclude traumatizing grain. New methods of noncontact grain separation from an ear in case of the threshing need to be developed. These methods exclude direct mechanical impact of operative parts on grains. A perspective method of noncontact grain separation from an ear is the imposition to a culm with an ear of oscillating motion, perpendicular its axes. It is a resonance in different parts of an ear can cause. As a result of the pilot and theoretical studies it is set that when impart low frequency oscillations in the range 18…100 Hz corresponding to natural frequencies of its oscillations to a culm with an ear, it is possible to achieve corrupting of the ear or its separation from the culm as a result of a resonance. But grain separation, at the same time, does not come from an ear as the range of natural resonance frequencies of grain oscillations does not match the range of natural frequencies of a culm with an ear and has higher values. The analysis of results of theoretical researches shows that for noncontact grain separation from an ear without its traumatizing is the imposition to it high-frequency oscillations in the range 100 … 14000 Hz matching its natural frequencies of oscillations, which is proved to be perspective. The occurring resonance causes origin of own movements of grain that leads to its separation from the ear

The article presents the results of a study of the apple tree rosette disease found in a collection garden and having a viral nature. The rosetting has typical signs of manifestation. Sick plants develop narrow small chlorotic leaves. Rosettes of leaves on the upper cervical and lateral shoots are formed as a result of the convergence of internodes. The spread of the rosetting in the planting reaches 10-11 %. The prevalence of viral disease varies among the 44 varieties of apple trees of different ecological and geographical origin. So, the lesion of rosetting was noted on single trees in the varieties of Gala Redi Red, Fujiko, Red Free, etc., and it was a complete defeat in the variety of Piros. A different degree of the manifestation of the disease on the trees was established: from partial manifestation on individual shoots, to aggressive damage to the entire crown of the tree. On young trees bearing fruiting (3-4 years from planting), the rosetting reduces the yield of apple trees by 36 %, ¼ part of the fruits on the trees are small in size compared to the fruits of healthy trees. The infectious nature of the rosetting is confirmed by the transfer of the disease on the most affected Piros variety using summer budding

The article is devoted to the study of the structural and functional organization of cereal and legume-cereal seed with intensive use in order to develop a model of agrophytocenoses with productive longevity and feed quality. A set of techniques has been developed to optimize the basic conditions of existence of highly productive, natural vegetation and on this basis to use grass stands rationally, create highly productive agrophytocenoses, and also grow artificial agrophytocenoses instead of degraded ones, helps to eliminate the negative consequences of the unreasonable exploitation of vegetation cover, improve its condition, significantly increase productivity and qualitative composition of natural ecosystems

The article studies species composition and abundance of soil algae under hybrid Krasnodar 292 AMB cultivated with various technologies. 7 species of cyanobacteria and 11 soil algae were revealed. It was revealed that the highest total amount of algae was observed in variants of environmentally acceptable and intensive technology, which is associated with the positive effect of mineral fertilizers and the consequent application of organic matter on soil algal flora. However, in these variants a decrease was observed both in the number of species and in the abundance of green and yellow-green algae. The species Botrydiopsis arhiza Borzi was absent or found in insignificant amounts. The species composition was less diverse, which can be attributed to the negative effect of the herbicide used in these technologies. The method of tillage had practically no effect on green, yellow-green and diatoms. An increase in the intensity of soil cultivation had a significant negative effect on both the species composition and the number of cyanobacteria

The studies were conducted on the biological economic efficiency of biological preparations against pests in the conditions of the training and experimental farm of the Federal State Budget Educational Institution of Higher Education of the Stavropol State Agrarian University in winter wheat crops of the Yuka variety. The effect of triple use of biosecticides Bioslip BV (viable spores of Beauveria bassiana OPB-09 strain) and Bioslip BT (viable spores and thermostable crystalline endotoxin of B. thuringiensis strains) was studied. A tank mixture of Alt-Alf chemical insecticides, CE (alpha-cypermethrin 100 ml / l) and Actara, VDG (thiamethoxam 250 g / kg) was used as a reference. Bioinsecticide Bioslip BV most effectively suppresses cereal aphids: the average biological effectiveness was 78.3%, in relation to harmful turtle and wheat thrips, the effectiveness of the drug was 60.3-68.7%. Bioinsecticide Bioslip BT is effective against the red-breasted drunkard; the average biological effectiveness was 84.2%, in relation to other species - 27.2-44.2%. The efficiency of using a tank mixture of bioinsecticides with half consumption rates was in the range of 23.3-40.7%. The harmfulness of phytophages in winter wheat crops is high, the control yield is lower by 0.556 t / ha compared with chemical treatment. The smallest difference with economic etholone in the variant with three times use of Bioslip BV is 0.09 t / ha

In the experiment, we have studied the effect of the use of an intelligent spreader on increasing the efficiency of nitrogen fertilizers used to feed winter wheat in ordinary chernozem. The studies were carried out in the production conditions of land use by AO SHP Kolos in the Kochubeyevsky district. In this article, we have examined the effect of a sprayer (Amazone UG 3000 Nova) and an intelligent mineral fertilizer spreader (Amazon ZA - TS - 4200) using touch sensors to determine the NDVI development index on the efficiency of nitrogen fertilizing winter wheat. Based on the experiments, it was found that, on average, over the two years of the study, the largest increase in the yield of winter wheat grains was noted in the variant with the introduction of ammonia nitrate in the first and second fertilizers using the intelligent fertilizer spreader Amazon ZA - TS - 4200 according to the NDVI - 6.53 t / ha. The highest structural indices of winter wheat grain yield were also noted in the variant with the introduction of ammonium nitrate in the first and second fertilizers using the Amazon ZA - TS - 4200 intelligent fertilizer spreader according to the NDVI index. So, the height of plants increased by 16.3 cm, the number of productive stems per 1 m2 by 37 pcs. The number of grains in the ear - by 5 pcs., The weight of 1000 grains - 0.8 g. According to the results of the experiments, it was established that in the conditions of land use by JSC "Agricultural Enterprise" Kolos "of the Kochubeyevsky District of the Stavropol region when planning the harvest of winter wheat - 6.5 tons / ha, it is advisable to use in the first and second top dressing of ammonium nitrate with a dose of 150 kg / ha, using the Amazon ZA - TS - 4200 intelligent fertilizer spreader according to the NDVI index

The article provides the results of hybrid forms studies and their control cultivars for several years of research. The phenological phases of Anemone coronaria experimental plants were studied during the autumn planting of tubers (October - November), biometric measurements were carried out. On average, seedlings in the control cultivars appeared after 5.6 weeks, and in hybrids – after 4.8 weeks. This period in the researched hybrid forms was shorter on 12% than in the control cultivars. The phase “from seedling emergence to flowering” was longer in the following hybrid forms: A-10-1 (for 7 days), M-3-97 (for 5 days), than in the control cultivars. The earliest flowering was observed in the M-4-98 hybrid form (March, 23), and at the latest - in the M-3-97 hybrid form (April, 4). The flower diameter in the A-10-1 hybrid form is 31.1% larger, than its control cultivar, in the G-13-133 hybrid form - 27.1% more, in the hybrid form M-3-97 - 13.6% more, and the hybrid M-4-98 - 18.8% more. The flowering time of hybrid forms is 63 days (9 weeks), and their control cultivars - 51 days (7.3 weeks). The vegetation period of the investigate plants was not exceed 174 days. Vegetation of the hybrid forms A-10-1, M-3-97, and M-4-98 lasted 32, 23, and 14 days longer than in their control cultivars

The purpose of the work was to test the winter wheat varieties artificially infected with North-Caucasus brown rust to identify its harmfulness. There was carried out a two-stage testing on two sets (8 and 10) of varieties that differed in their resistance to the pathogen. As a result, there has been identified high brown rust harmfulness in susceptible varieties, which led to a yield decrease from 16.3 to 32.2%. Among the maximum infected varieties, there has been identified the most tolerant variety ‘Tarasovskaya 29’ which, when damaged to 100%, had a minimum yield decrease (less than 10.6%). The poorly susceptible to brown rust varieties reduced their yields from 11.2% to 20.7%. Among them, the variety ‘Spartak’ showed lower rates of a yield decline. Among the five varieties that showed an average brown rust affection, there have been noted various indicators of a yield decrease. The variety ‘Donskaya Yubileynaya’ showed a minimum decrease of a yield and its structural elements under the conditions of artificial infection with brown rust; and together with the variety ‘Tarasovskaya 29’ can be classed to the varieties tolerant to brown rust. When predicting brown rust epiphytoty the susceptible and medium-resistant wheat varieties require obligatory protection with fungicides

Considering the fact that in Russia the development of dairy cattle breeding is based on increasing milk production in terms of providing this product, the further increase in milk yield and quality of cow's milk remains important. Some farms in Russia, including the Krasnodar region, have reached high milk production rates in whole herds of up to 12-13 thousand kg of milk per cow. Today it is important to “propagate” such farms. To achieve this goal, it is necessary to study their livestock breeders experience, approaches to the selection of cattle (calves, heifers, cows), to form herds of animals that can get high milk yield under the conditions created for them. The farm in which we conducted our scientific research is distinguished by the fact that much attention is paid to maintaining a high level of breeding and breeding, as well as to creating optimal factors for keeping, feeding and caring for animals. Agroholding Step includes 5 farms in divisions: one in the Kuban Step, two in public company of shareholders “Rodina” and two in shareholder company “Novoplastunovskaya” Three farms are located in the village of Chelbasskaya, where the cowsheds were reconstructed and equipped with new equipment. In the village of Novoplastunovskaya, new buildings were built in the territory of the old farm, and the 4th farm was built in 2018 in the new territory. All farms contain highly productive breeding cows of the Holstein breed. The Russian information programs “Selex-Dairy Cattle” and Israeli program “AfiFarm” were introduced. We have studied zoohygienic conditions in various buildings of dairy farms in the spring, where animals are constantly kept. The results obtained indicate that the cows are kept in comfortable conditions, allowing them to eat a balanced diet in accordance with their needs and to avoid many stresses what is important for the secretion of milk. Indicators of genetic potential for milk production of cows and the effectiveness of its manifestation are also determined

The article discusses the relevance of the use of protected amino acids (lysine and methionine) in animal husbandry of the Krasnodar region, using the example of the farm "Krasnodar". The highest milk yield was obtained from cows with the combined addition of lysine and methionine in their diet. In relation to control (CR), the average daily milk yield in the group with combined additives (CR+L+M) was 38.4 kg/day. In addition, there was a positive effect of lysine and the combined additive (CR+L+M) on protein and fat in milk. Protected methionine (CRM) had no effect on the yield of fat and protein in milk. It was noted that additives of protected amino acids in groups with lysine and combined amino acids reduced the cost of dry matter (DM) and metabolizable energy (ME) per kg of milk. The results of our studies have shown that the productive milk response and its components are affected by the amount of the first limiting amino acid in the diet. Also, the supply of protected lysine changed the plasma concentration of animals and improved the availability of amino acids for milk protein synthesis

One of the key problems facing the credit institution is the late payment of the loan. Firstly, it is a deeper analysis - in order to be carried out “manually” it is not even required several days, but weeks. Secondly, it allows you to work with clients much faster. And most importantly scoring allows you to negate the influence of the human factor. An automated system, no matter how you look, cannot be liked or not. Data analysis is only based on facts. Scoring is beneficial to all. The bank is able to work faster and reduce the risk of loan defaults. Clients, in turn, can apply for a loan on terms that are more favorable

This article is devoted to rating assessment of the socio-economic situation of the Krasnodar region, presented by such agencies as "RAEKS-Analytics", "Expert RA" and "National Rating Agency". The methodologies used by these agencies were studied and analyzed. A comparison of these methodologies was also conducted. As a result, a number of their shortcomings were identified, including the lack of a complete methodological model in the public domain. Some agencies do not provide links to statistics that are used in the analysis. In the article using the STATISTICA environment, a statistical analysis of data reflecting the level of socio-economic situation of the Krasnodar region is carried out. Based on the work [12], the article created a discriminant model for assessing the socio-economic development of urban districts of the Krasnodar region with a confidence of 85%. The study conducted a cluster, discriminant, classification (decision trees), coefficient (proposed by the authors) based on the data of the Federal State Statistics website for the period from 2009 to 2018 in the city districts: Krasnodar, Anapa, Armavir, Gelendzhik, Goryachiy Klyuch, Novorossiysk Sochi. During the study, analyzes such as cluster and classification trees showed poor results, since they are not able to detect latent nonlinear relationships between the study indicators. Using the constructed discriminant model, we have carried out an analysis of the socio-economic development of urban districts of the Krasnodar region for the period 2009-2018, which allows us to identify the leaders and the outsiders

Dynamic programming is designed to solve discrete optimal control problems. According to this method, the optimal solution in a multidimensional problem is found by decomposing it into stages, each of which represents a subproblem with respect to one variable. In economic problems, the number of stages is the planning horizon. The choice of a planning horizon is necessary for a rigorous statement of the applied problem in the field of economics and management, but it is often difficult to justify. We see a way out in the use of asymptotically optimal plans for which the values of the optimization criterion differ little from its values for optimal plans for all sufficiently large planning horizons. The main result of the paper is the existence of an asymptotically optimal plan. The proof is carried out in several statements. If the sum of the maximums of the transition functions tends to 0, the existence of an asymptotically optimal plan is obtained in Theorem 1. A special case is models with a discount at a discount coefficient less than 1. The main part of the article is devoted to models with a discount coefficient equal to 1. Theorem 2 on the highway is proved for base set of a finite number of elements. In Theorem 3, a statement is obtained on the approximation of an arbitrary set by a finite one. In the final Theorem 4, the existence of an asymptotically optimal plan is proved in the general case. The term “magistral” is associated with a well-known recommendation to drivers: in order to get from point A to point B, it is advisable to go to the highway (magistral) at the initial section of the road, and then exit the highway and get to point B. The recommendation for choosing the optimal one is similar trajectories using the Pontryagin maximum principle in the model of the optimal distribution of time between obtaining knowledge and developing skills. This fact underlines the methodological proximity of dynamic programming and the Pontryagin maximum principle