Processing of Polymers Stress Relaxation Curves Using Machine Learning Methods

حاليًا، أحد المجالات الموضوعية لتطبيق طرق التعلم الآلي هو التنبؤ بالخصائص المادية. الهدف من هذا العمل هو تطوير نماذج التعلم الآلي لتحديد الخصائص الريولوجية للبوليمرات من منحنيات استرخاء الإجهاد التجريبية. تقدم الورقة لمحة عامة عن الاتجاهات الرئيسية للنهج الميتاهويرية (البحث المحلي، والخوارزميات التطورية) لحل مشاكل التحسين التوافقي. يتم وصف الخوارزميات الميتاهورية لحل بعض مشاكل تحسين التوافقية المهمة، مع التركيز بشكل خاص على بناء أشجار القرار. تم إجراء تحليل مقارن للخوارزميات لحل مشكلة الانحدار في CatBoost Regressor. . الهدف من الدراسة هو مجموعات البيانات المتولدة التي تم الحصول عليها على أساس منحنيات استرخاء الإجهاد النظرية. وترد جداول البيانات الأولية لنماذج التدريب لجميع العينات، ويجري تحليل إحصائي لخصائص مجموعات البيانات الأولية. كان العدد الإجمالي للتجارب العددية لجميع العينات 346020 اختلافًا. عند تطوير النماذج، تم استخدام طرق CatBoost للذكاء الاصطناعي، وتم استخدام طرق التسوية (تحلل الوزن، وتسوية الوزن المفصول، وزيادة) لتحسين دقة النموذج، وتم استخدام طريقة Z-Score لتطبيع البيانات. نتيجة للدراسة، تم تطوير نماذج ذكية لتحديد المعلمات الريولوجية للبوليمرات المدرجة في معادلة ماكسويل-غوريفيتش غير الخطية المعممة (لزوجة الاسترخاء الأولية، وحدة السرعة) باستخدام مجموعات البيانات المولدة لرابط الإيبوكسي EDT-10 كمثال. بناءً على نتائج اختبار النماذج، تم تقييم جودة النماذج، ورسم رسوم بيانية للتنبؤات للمتدربين وعينات الاختبار، ورسوم بيانية لأخطاء التنبؤ. تستند النماذج الذكية إلى خوارزمية CatBoost ويتم تنفيذها في بيئة دفتر المشتري في بايثون. اجتازت النماذج المشيدة تقييم الجودة وفقًا للمقاييس التالية: MAE و MSE و RMSE و MAPE. كانت القيمة القصوى لتنبؤات خطأ النموذج 0.86 لمقياس MAPE، والقيمة الدنيا لتنبؤات خطأ النموذج كانت 0.001 لمقياس    MSE. تقديرات أداء النموذج التي تم الحصول عليها أثناء الاختبار.Currently, one of the topical areas of application of machine learning methods is the prediction of material characteristics. The aim of this work is to develop machine learning models for determining the rheological properties of polymers from experimental stress relaxation curves. The paper presents an overview of the main directions of metaheuristic approaches (local search, evolutionary algorithms) to solving combinatorial optimization problems. Metaheuristic algorithms for solving some important combinatorial optimization problems are described, with special emphasis on the construction of decision trees. A comparative analysis of algorithms for solving the regression problem in CatBoost Regressor has been carried out. The object of the study is the generated data sets obtained on the basis of theoretical stress relaxation curves. Tables of initial data for training models for all samples are presented, a statistical analysis of the characteristics of the initial data sets is carried out. The total number of numerical experiments for all samples was 346020 variations. When developing the models, CatBoost artificial intelligence methods were used, regularization methods (Weight Decay, Decoupled Weight Decay Regularization, Augmentation) were used to improve the accuracy of the model, and the Z-Score method was used to normalize the data. As a result of the study, intelligent models were developed to determine the rheological parameters of polymers included in the generalized non-linear Maxwell-Gurevich equation (initial relaxation viscosity, velocity modulus) using generated data sets for the EDT-10 epoxy binder as an example. Based on the results of testing the models, the quality of the models was assessed, graphs of forecasts for trainees and test samples, graphs of forecast errors were plotted. Intelligent models are based on the CatBoost algorithm and implemented in the Jupyter Notebook environment in Python. The constructed models have passed the quality assessment according to the following metrics: MAE, MSE, RMSE, MAPE. The maximum value of model error predictions was 0.86 for the MAPE metric, and the minimum value of model error predictions was 0.001 for the MSE metric. Model performance estimates obtained during testing are valid

The Influence of Meteorological Parameters and Other Factors on Soil Radon Dynamics

The paper presents the results of the research in the degree of the effect of space weather meteorological parameters and factors on the dynamics of soil radon levels and [alpha]- and [beta]-radiation flux densities in a seismically passive region. The cross-correlation analysis showed a significant correlation of [beta]-radiation flux density with temperature in summer, and no correlation in winter. A significant relation between [alpha]- and [beta]-radiation flux densities and pressure within the intra-annual range was not observed. The investigation of the high-intensity precipitation effect on radon volumetric activity and [alpha]- and [beta]-radiation flux densities showed their abnormal increase. The dependence of the anomaly duration on the depth was revealed. The abnormal jumps in [alpha]- and [beta]-radiation flux densities data series occur in the snow-melting periods as well. Low-intensity precipitations significantly violate the standard "diurnal variations" of [alpha]- and [beta]-radiation soil fluxes and radon volumetric activity. Fourier analysis showed the diurnal (24 hours) and semidiurnal (12 hours) harmonics for the observed radiation values at a depth of 0.5 m. The obtained results can be used for interpretation of the data on the soil radon monitoring in order to predict earthquakes, etc

FOREIGN EXPERIENCE FOR ECONOMIC DEVELOPMENT SMALL AND MEDIUM-SIZED BUSINESSES

To ensure the sustainable economic development of Ukraine important to study and introduction of international experience of small and medium enterprises, which directly determines the degree of development of the economy as a whole. Thus, in the EU small and medium-sized businesses account for about 90% of the total number of enterprises. Implementation small and medium-sized businesses its substantial economic and social role is only possible with sound public policy full support for this sector.Assistance and support SME is an independent component of public policy in many countries. Therefore, there are special state (government) authorities (coordination) and support for small and medium businesses.Key words: investment, innovation, small and medium-sized businesses, the economy

CHANGING SCHOOL-BASED ANXIETY DURING PHYSICAL EDUCATION, TAKING THE INDIVIDUAL TYPOLOGICAL APPROACH INTO ACCOUNT

Purpose of the study: The purpose of the study is to identify changes in school-based anxiety in children aged 12 – 13 during their physical education using a special Program for the individual typological approach implementation. Methodology: Two groups had been formed: reference and experimental (25 people each); three methods were used (Method for studying individual typological peculiarities of middle-school children by A. Belov, Method of Kondash's anxiety scale (1973), and Method of identifying general physical education of students); diagnostic testing of physical fitness was conducted (long jump from the spot; lifting the body in 30 sec. (press); push-up (girls); pulling up on the crossbar (boys); running 30 meters, shuttle running 3x10; bending forward from a sitting position). Main Findings: The results of the study have been statistically processed with Excel 2000 and STATISTICA 8.0, using the Student's t-test for dependent and independent samples. The M average has been found; the differences have been considered significant at p < 0.05. Applications of this study: The Program for the individual typological approach implementation has been compiled with an emphasis on reducing school-based anxiety in children aged 12 – 13; its features, objectives, indicators, criteria, content, and forms of implementation have been substantiated; a set of general physical exercises has been developed for each type of temperament, which includes the exercises for some groups of muscles of the upper shoulder girdle, back muscles, abdomen, and hips. Novelty/Originality of this study: The significant improvement in the physical fitness of students from the experimental group compared to the reference one identified during the term proves the efficiency of the implemented physical education program, taking into account the individual typological approach to the personality of adolescents with an emphasis on reducing their school-based anxiety. The results of the study have allowed formulating recommendations for improving the approaches to conducting physical education classes

Sources of agronomically important traits for breeding of soft spring wheat (Triticum aestivum L.) in the forest steppe of Novosibirsk region

The efficiency of donors in plant breeding depends on the degree of knowledge of the physiological and genetic background of agronomic characters. The research is aimed to assess quantitative agronomic traits (1000-grain weight, grain weight, grain number per spike and spikelet number per spike) in soft spring wheat varieties with different maturation timing in order to identify genotypes that show the best adaptation to the regional environment, high yield and resistance to stress. Agronomic traits were studied in 139 soft spring wheat varieties in contrasting years. The cultivars were divided into the following maturation groups: mid-early and early (31 plants), middle (94 plants) and mid-late (14 plants). In the mid-early and early group, Leningradskaya 97 and Rosinka 1 had three measures of maturation (grain weight per spike, grain number per spike, and spikelet number per spike) higher than the group average. In the middle group, Baganskaya 51, Prokhorovka, Omskaya kormovaya, Amir and Lada each had two or more measures significantly higher than the group average. In the midlate group, the winners were Omskaya 24 (grain weight per spike, grain number per spike and spikelet number per spike), Sibirskaya 16 (grain weight per spike and spikelet number per spike) and Ishimskaya 98 (1000-grain weight and spikelet number per spike). Varieties identified and characterized in this way can be used in the selection process as a source of higher 1000-grain weight, grain number per spike, spikelet number per spike and grain weight per spike. A tendency towards increase has been demonstrated for 1000-grain weight, spikelet number per spike and grain weight per spike depending on the length of the growing season. No reduction in vegetation period was observed in epiphytotic years in susceptible varieties as compared to resistant varieties