NEURO-MECHANICAL METHODS OF CONTROL AND DIAGNOSTICS OF THE TECHNICAL STATE OF AIRCRAFT ENGINE TV3-117 IN FILM REGIONS

 Предметом дослідження в статті є режими роботи авіаційного двигуна ТВ3-117 та методи їх контролю і діагностики. Мета роботи – розробка методів контролю і діагностики технічного стану авіаційного двигуна ТВ3-117 на основі нейромережевих технологій у режимі реального часу. В статті вирішуються наступні завдання: обґрунтування передумов застосування нейронних мереж у задачі контролю і діагностики технічного стану авіаційного двигуна ТВ3-117, побудова узагальненої нейронної мережі та вибір алгоритму її навчання, розв’язок задачі контролю параметрів технічного стану авіаційного двигуна ТВ3-117 із застосуванням нейронних мереж. Використовуються такі методи: методи теорії ймовірностей і математичної статистики, методи нейроінформатики, методи теорії інформаційних систем та обробки даних. Отримано наступні результати: Обґрунтовано доцільність застосування нейронних мереж у задачі контролю і діагностики технічного стану авіаційного двигуна ТВ3-117. Обґрунтовано доцільність розробки нейронних мереж на базі на базі нейрорегулятора NN Predictive Controller. Обґрунтовано доцільність застосування градієнтного методу навчання нейронних мереж, а також розроблено метод навчання нейрорегулятора на основі нейромодулятора із застосуванням методу зворотного поширення помилки. Отримано розв’язок задачі контролю параметрів технічного стану авіаційного двигуна ТВ3-117, який підтверджує доцільність застосування нейронних мереж у задачі контролю і діагностики технічного стану авіаційного двигуна ТВ3-117. Висновки: Застосування нейромережевих технологій э ефективним при розв’язку широкого кола погано формалізованих задач, однією з яких є задача контролю технічного стану авіаційного двигуна ТВ3-117. Перевагою нейронних мереж при їх застосуванні у задачах контролю і діагностики технічного стану авіаційного двигуна ТВ3-117 є можливість роботи з малими навчальними вибірками, призначенням м’яких допусків, використанням досвіду експертів для оцінки технічного стану авіаційного двигуна ТВ3-117, що є важливим в умовах неповноти інформації.Ключові слова: авіаційний двигун, нейронна мережа, технічний стан, контроль і діагностикаThe subject of the study in the article is the modes of operation of the aircraft engine TV3-117 and methods of their control and diagnostics.  The purpose of the work is to develop methods of control and diagnostics of the technical condition of the aircraft engine TV3-117 on the basis of neural network technologies in real time.  The following tasks are solved: substantiation of the preconditions of the use of neural networks in the task of control and diagnostics of the technical condition of the aircraft engine TV3-117, construction of the generalized neural network and the choice of the algorithm for its training, the solution of the task of controlling the parameters of the technical condition of the aircraft engine TV3-117 with the use of neural networks.  The following methods are used: methods of probability theory and mathematical statistics, methods of neuroinformatics, methods of the theory of information systems and data processing.  The following results were obtained: The feasibility of using neural networks in the task of controlling and diagnosing the technical condition of the aircraft engine TV3-117 was substantiated.  The expediency of developing neural networks based on the NN Predictive Controller. The expediency of using the gradient method of teaching neural networks is substantiated, as well as the method of training a neuro-regulator based on a neuro-modulator with the use of the method of reverse error propagation.  The expediency of using the gradient method of teaching neural networks is substantiated, as well as the method of training a neuro-regulator based on a neuro-modulator with the use of the method of reverse error propagation. The solution of the task of controlling the parameters of the technical condition of the aircraft engine ТВ3-117, which confirms the expediency of using neural networks in the task of control and diagnostics of the technical condition of the aircraft engine TV3-117, is obtained. Conclusions: The application of neural network technologies is effective in solving a wide range of poorly formalized tasks, one of which is the task of controlling the technical condition of the aircraft engine TV3-117. The advantage of neural networks in their application in the tasks of control and diagnostics of the technical condition of the aircraft engine TV3-117 is the possibility of working with small training samples, the appointment of soft tolerances, using the experience of experts to assess the technical condition of the aircraft engine TV3-117, which is important in the condition’s information incompleteness.Keywords: engine, neural network, technical condition, control and diagnosi

How Are Adolescents Sleeping? Adolescent Sleep Patterns and Sociodemographic Differences in 24 European and North American Countries.

PURPOSE:Insufficient and poor sleep patterns are common among adolescents worldwide. Up to now, the evidence on adolescent sleep has been mostly informed by country-specific studies that used different measures and age groups, making direct comparisons difficult. Cross-national data on adolescent sleep that could inform nations and international discussions are lacking. We examined the sleep patterns of adolescents across 24 countries and by gender, age, and affluence groups. METHODS:We obtained sleep data on 165,793 adolescents (mean age 13.5 years; 50.5% girls) in 24 European and North American countries from the recent cross-sectional Health Behaviour in School-aged Children surveys (2013-2014 and 2017-2018). For each country, we calculated the age-standardized mean in sleep duration, timing, and consistency and the proportions meeting sleep recommendations on school and nonschool days from self-reported bedtimes and wake times. We conducted stratified analyses by gender, age, and family affluence group. RESULTS:Adolescent sleep patterns varied cross-nationally. The average sleep duration ranged between 7:47 and 9:07 hours on school days and between 9:31 and 10:22 hours on nonschool days, and the proportion of adolescents meeting sleep recommendations ranged between 32% and 86% on school days and between 79% and 92% on nonschool days. Sleep patterns by gender and affluence groups were largely similar, but older adolescents slept less and went to bed later on school days than younger adolescents in all countries. CONCLUSIONS:The sleep patterns of adolescents vary across countries and sociodemographic groups. Insufficient sleep on school days is common in many countries. Public health and policy efforts to promote healthy adolescent sleep are encouraged

Influence of socioeconomic factors on pregnancy outcome in women with structural heart disease

OBJECTIVE: Cardiac disease is the leading cause of indirect maternal mortality. The aim of this study was to analyse to what extent socioeconomic factors influence the outcome of pregnancy in women with heart disease.  METHODS: The Registry of Pregnancy and Cardiac disease is a global prospective registry. For this analysis, countries that enrolled ≥10 patients were included. A combined cardiac endpoint included maternal cardiac death, arrhythmia requiring treatment, heart failure, thromboembolic event, aortic dissection, endocarditis, acute coronary syndrome, hospitalisation for cardiac reason or intervention. Associations between patient characteristics, country characteristics (income inequality expressed as Gini coefficient, health expenditure, schooling, gross domestic product, birth rate and hospital beds) and cardiac endpoints were checked in a three-level model (patient-centre-country).  RESULTS: A total of 30 countries enrolled 2924 patients from 89 centres. At least one endpoint occurred in 645 women (22.1%). Maternal age, New York Heart Association classification and modified WHO risk classification were associated with the combined endpoint and explained 37% of variance in outcome. Gini coefficient and country-specific birth rate explained an additional 4%. There were large differences between the individual countries, but the need for multilevel modelling to account for these differences disappeared after adjustment for patient characteristics, Gini and country-specific birth rate.  CONCLUSION: While there are definite interregional differences in pregnancy outcome in women with cardiac disease, these differences seem to be mainly driven by individual patient characteristics. Adjustment for country characteristics refined the results to a limited extent, but maternal condition seems to be the main determinant of outcome

Hypopituitarism is associated with lower oxytocin concentrations and reduced empathic ability

Purpose Central diabetes insipidus is characterised by arginine vasopressin deficiency. Oxytocin is structurally related to vasopressin and is synthesised in the same hypothalamic nuclei, thus we hypothesised that patients with acquired central diabetes insipidus and anterior hypopituitarism would display an oxytocin deficiency. Moreover, psychological research has demonstrated that oxytocin influences social and emotional behaviours, particularly empathic behaviour. We therefore further hypothesised that central diabetes insipidus patients would perform worse on empathy-related tasks, compared to age-matched and gender-matched clinical control (clinical control-isolated anterior hypopituitarism) and healthy control groups. Method Fifty-six participants (age 46.54 ± 16.30 yrs; central diabetes insipidus: n = 20, 8 males; clinical control: n = 15, 6 males; healthy control: n = 20, 7 males) provided two saliva samples which were analysed for oxytocin and completed two empathy tasks. Results Hypopituitary patients (both central diabetes insipidus and clinical control groups) had significantly lower oxytocin concentrations compared to healthy control participants. Hypopituitary patients also performed significantly worse on both the reading the mind in the eyes task and the facial expression recognition task compared to healthy control participants. Regression analyses further revealed that central diabetes insipidus patients’ oxytocin concentrations significantly predicted their performance on easy items of the reading the mind in the eyes task. Conclusions Hypopituitarism may therefore be associated with reduced oxytocin concentrations and impaired empathic ability. While further studies are needed to replicate these findings, our data suggest that oxytocin replacement may offer a therapeutic approach to improve psychological well-being in patients with hypopituitarism

Mathematical modeling of non-stationary gas flow modes along a linear section of a gas transmission system

Article demonstrates the applicability of modeling non-stationary non-isothermal gas flow along a linear section of a gas transmission system by means of using various numerically simulated models and sophisticated numerical techniques. There are described several models of non-stationary non-isothermal regimes of gas flow along the pipeline section. They are included in the considered general model and their comparative analysis is carried out by the virtue of numerical simulation. The finite difference algorithm is used to solve the simultaneous equations of the numerically simulated model for the pipeline section. The results of calculating the gas flow parameters using various models are presented: both with and without taking into account kinetic energy, as well as both with and without taking into account the Joule–Thompson effect. The matter of choosing the appropriate model is discussed. The obtained results can be used at the stage of transfer pipeline system operation in order to develop scientifically well-founded recommendations for improving the safety and efficiency of the pipeline transportation system.</jats:p