Learning analytics in massive open online courses as a tool for predicting learner performance

Learning analytics in MOOCs can be used to predict learner performance, which is critical as higher education is moving towards adaptive learning. Interdisciplinary methods used in the article allow for interpreting empirical qualitative data on performance in specific types of course assignments to predict learner performance and improve the quality of MOOCs. Learning analytics results make it possible to take the most from the data regarding the ways learners engage with information and their level of skills at entry. The article presents the results of applying the proposed learning analytics algorithm to analyze learner performance in specific MOOCs developed by Ural Federal University and offered through the National Open Education Platform. © 2018, National Research University Higher School of Economics.This study was support- ed by financial assis- tance provided under the Resolution of the Government of the Rus sian Federation No. 211, Contract No. 02. A03.21.0006. Translated from Russian by I. Zhuchkova

Behaviour of the Blazar CTA 102 during two giant outbursts

Blazar CTA 102 underwent exceptional optical and high-energy outbursts in 2012 and 2016-2017. We analyze its behaviour during these events, focusing on polarimetry as a tool that allows us to trace changes in the physical conditions and geometric configuration of the emission source close to the central black hole. We also use Fermi gamma-ray data in conjunction with optical photometry in an effort to localize the origin of the outbursts.AST-1615796 - Boston Universit

МЕТОДИКА ОЦЕНКИ ЭФФЕКТИВНОСТИ ИСПОЛЬЗОВАНИЯ В СИСТЕМЕ ЭЛЕКТРОСНАБЖЕНИЯ ПОЛУПРОВОДНИКОВЫХ ПРЕОБРАЗОВАТЕЛЕЙ ПОСТОЯННОГО НАПРЯЖЕНИЯ

Purpose. To specify efficiency evaluation of the DС-DC power semiconductor converter application in the power-supply system. Methodology. We have chosen application version of converter and then used the statistical modeling of DC-DC converter for its efficiency evaluation at varied input voltage according to proposed technique. We have compared the simulated result with the data presented in reference literature. Results. We have proposed the efficiency evaluation technique of converter application. Proposed technique includes detection of external factors influenced on the converter efficiency; development of efficiency evaluation models; selecting application version of converter; determination of the correlation coefficients between the values of external factors; definition of the converter efficiency; obtaining of the converter efficiency distribution. Originality. For the first time, we have developed the evaluation technique of converter efficiency corrected for application version of converter. Practical value. Presented in the study results could be useful for specialists in semiconductor equipment, electrical facilities and systems.Разработана методика оценки эффективности использования силового полупроводникового преобразователя постоянного напряжения в системе электроснабжения. Методика включает выявление множества внешних факторов, влияющих на эффективность использование преобразователя; разработку модели оценки эффективности как функции внешних факторов; выбор варианта использования преобразователя; установление коэффициентов корреляции между значениями внешних факторов; определение значений КПД преобразователя; нахождение распределения КПД преобразователя. Применение предложенной методики проиллюстрировано на примере синхронного промежуточного вольтодобавочного преобразователя постоянного напряжения. Для этой цели выполнено статистическое моделирование преобразователя этого типа при стохастичном изменении входного напряжения.Розроблено методику оцінки ефективності використання силового напівпровідникового перетворювача постійної напруги в системі електропостачання. Методика включає виявлення множини зовнішніх чинників, що впливають на ефективність використання перетворювача; розробку моделі оцінки ефективності як функції зовнішніх чинників; вибір варіанта використання перетворювача; встановлення коефіцієнтів кореляції між значеннями зовнішніх чинників; визначення значень ККД перетворювача; знаходження розподілу ККД перетворювача. Застосування запропонованої методики проілюстровано на прикладі синхронного проміжного вольтододаткового перетворювача постійної напруги. Для цієї мети виконано статистичне моделювання перетворювача цього типу при стохастичній зміні вхідної напруги

Risk Assessment at the Cosmetic Product Manufacturer by Expert Judgment Method

A case study was performed in a cosmetic product manufacturer. We have identified the main risk factors of occupational accidents and their causes. Risk of accidents is assessed by the expert judgment method. Event tree for the most probable accident is built and recommendations on improvement of occupational health and safety protection system at the cosmetic product manufacturer are developed. The results of this paper can be used to develop actions to improve the occupational safety and health system in the chemical industry

Left ventricular diastolic dysfunction and transmitral blood flow parameters in patients after COVID-19

Background. People who previously had COVID-19 infection have an increased risk of developing cardiovascular diseases. Left ventricular diastolic dysfunction is an early marker of the development of cardiac pathology. Its early detection is important for the adequate therapy order and dynamic monitoring of patients. In this regard, it seems relevant to study the effect of a recent COVID-19 infection on the left ventricular diastolic function and transmitral blood flow parameters in apparently healthy individuals without clinical and instrumental signs of cardiovascular pathology. The aim of the study. To assess the changes in the diastolic and systolic function of  the left ventricle, its anatomical parameters and transmitral blood flow parameters in two groups of  apparently healthy individuals: those who had and those who had not COVID-19 infection. Materials and methods. Transthoracic echocardiography was performed according to the standard technique and its results were analyzed in 66 examined patients who were recognized as apparently healthy according to the results of  regular comprehensive clinical and instrumental studies. The first group included 30 individuals who underwent an echocardiographic study before or during the COVID-19 pandemic, but did not have a coronavirus infection; the second group consisted of 36 people who recovered from COVID-19. The indicators of the presence of left ventricular diastolic dysfunction and the transmitral blood flow parameters were assessed. The study was approved at a meeting of the Medical Ethics Committee under the Ministry of Health of the Republic of Karelia and of Petrozavodsk State University (Minutes No. 47 of 01.11.2023). Results. The frequency of the left ventricular diastolic dysfunction did not differ in  the  first and second groups of patients. Statistically significant differences were recorded in the average flow deceleration time for both early and late filling of the left ventricle in people who had and did not have COVID-19 infection. A change in the phase structure of the transmitral blood flow may be an early manifestation of intracardiac hemodynamic disorders in people who have recovered from COVID-19

Economic Aspects of Emergency Transition to Distance Education, or The Price of Going Online in Higher Education

As Russian universities switched to distance education in March 2020 to prevent COVID-19 from spreading, self‑paying students started questioning the fairness of tuition fees during the pandemic. They fled petitions, emphasizing that distance learning could not be equated to traditional classroom‑based learning, that educational services were not delivered to the full extent, and that educational quality had decreased. On those grounds, students required cutting tuition fees down to the size of those in part‑time or extramural education. To understand whether universities can afford making this step, we undertake to measure the price that they have paid for the transition to distance learning. For this purpose, we use data from a survey of faculty teaching and curriculum organization practices carried out at a federal university between March 23, 2020 and June 21, 2020, which involved 4,099 faculty members, as well as financial records of some departments within that university. Findings show that teaching workload reduced by 15% with distance learning during the pandemic, and the number of contact hours decreased 1.7 times. However, the overall amount of faculty workload increased by 50%, first of all due to a 2.4-time rise in curriculum organization activities. Therefore, the transition to distance education led to a significant increase in faculty workload, given that contact hours were preserved. Furthermore, the university invested heavily in the transition to distance learning and continuity of educational processes during the pandemic, in particular by financing the establishment of a new department for digitalization of learning processes. An inference is made that distance education imposed by the pandemic has not been reduced to part‑time or extramural studies. Decisions about cutting tuition fees for self‑paying students should be made at the institutional level, with due regard for faculty workload and digitization costs. © 202

Assessment of bone quality by the technique of multispiral computer tomography in patients with chronic osteomyelitis

Purpose - to study the roentgenomorphological features of the lower limb long bones in patients with chronic osteomyelitis using the technique of multi-spiral computer tomography (MSCT), and to propose the complex of parameters to assess bone quality. Material and methods. Roentgenography and computer tomography of the hips were performed in 49 patients with chronic osteomyelitis of long bones of lower extremities. The studies made using computer tomographs GE Light Speed VCT, Toshiba Aquilion-64, Somatom Smile. Results. The changes in bone structure of proximal femur were characterized by extremely marked polymorphism, and they almost didn’t repeat in the anatomical component. The cortical plate had heterogenous structure with resorption zones in the area of its transfer to the shaft. The character of roentgenomorphological changes in the shaft was individual in all the patients, but there were common manifestations as well which consisted in thickening of the cortical plate, different intensity of periosteal and endosteal layers. The cortical plate was significantly different in density, which exceeded 1700 HU in some places. When osteomyelitic process localized in the knee marked changes affected its all components, they manifested themselves in extended osteoporosis and local osteosclerosis. When osteomyelitic process localized in proximal tibia extensive resorption zones observed, the cortical plate thinned in proximal parts, its density was not more than 350 HU. Conclusion. The data demonstrated that bone quality in patients with chronic osteomyelitis had significant deviations from normal values in terms of changing both its density and architectonics. The deviations consisted in bone density decrease in the meta-epiphyseal part regardless of the process localization, in highly variable density values of the cortical plate as a result of its thickening or thinning, presence of resorption or sclerosis areas