Effect of pulse flows of charged particles on the structure and mechanical properties of metals

We investigate the effect of pulse flows of hydrogen, helium, and hydrogen-helium plasma of a specific power of 20-30 GW/m² on the surface structure and mechanical properties of vanadium, niobium, and Kh16N15M3B and Kh18N10T austenitic stainless steelsyesBelgorod State Universit

MOOC introduction into educational process: experience of on-line courses integration in university educational programs

The article presents the results of a study on the introduction of mass open online courses into educational programs of the Belgorod State National Research Universit

Response of the solar atmosphere to magnetic field evolution in a coronal hole region

Methods. We study an equatorial CH observed simultaneously by HINODE and STEREO on July 27, 2007. The HINODE/SP maps are adopted to derive the physical parameters of the photosphere and to research the magnetic field evolution and distribution. The G band and Ca II H images with high tempo-spatial resolution from HINODE/BFI and the multi-wavelength data from STEREO/EUVI are utilized to study the corresponding atmospheric response of different overlying layers. Results. We explore an emerging dipole locating at the CH boundary. Mini-scale arch filaments (AFs) accompanying the emerging dipole were observed with the Ca II H line. During the separation of the dipolar footpoints, three AFs appeared and expanded in turn. The first AF divided into two segments in its late stage, while the second and third AFs erupted in their late stages. The lifetimes of these three AFs are 4, 6, 10 minutes, and the two intervals between the three divisions or eruptions are 18 and 12 minutes, respectively. We display an example of mixed-polarity flux emergence of IN fields within the CH and present the corresponding chromospheric response. With the increase of the integrated magnetic flux, the brightness of the Ca II H images exhibits an increasing trend. We also study magnetic flux cancellations of NT fields locating at the CH boundary and present the obvious chromospheric and coronal response. We notice that the brighter regions seen in the 171 A images are relevant to the interacting magnetic elements. By examining the magnetic NT and IN elements and the response of different atmospheric layers, we obtain good positive linear correlations between the NT magnetic flux densities and the brightness of both G band (correlation coefficient 0.85) and Ca II H (correlation coefficient 0.58).Comment: 9 pages, 9 figures. A&A, in pres

COVID 19 Accelerator of Changes in the Readiness of University Teachers to Use Distant Learning Technologies

The article describes the experience of the Belgorod State University (BelSU) in organizing the educational process during the forced transition to full distant learning due to COVID-19. The authors present the results of the study of changes in the readiness of the university faculty to use distant learning technologie

Effects of Severe Data Imbalance on Evaluation of Support Vector Machines and Decision Trees

Data imbalance refers to a phenomena when one of the classes is much better represented in the dataset compared to the others. Many researchers have been facing data imbalances in various fields, including medicine, fraud or device failure detection, and predicting conversions from user behavior data. Even though there exist a significant number of papers devoted to predicting user behavior, a closer analysis of data imbalances and how they affect performance of classifiers and model evaluation is missing in this literature. This thesis attempts to fill this gap. In this thesis work, support vector machines and decision trees are employed to predict whether a website user is interested in making a purchase of a certain product or not. Each of the classifiers is evaluated using four strategies: balanced training and testing data, balanced training and unbalanced testing data, unbalanced training and balanced testing data, unbalanced training and testing data. The metrics used for models’ performance evaluation are: Accuracy, Precision, F1, MCC, Sensitivity, Specificity and ROC-AUC. The learning curves are built for each of the metrics to evaluate how performance changes when training sample size increases. Hierarchical clustering is applied to evaluate how dimensionality reduction affects the performance. Predictions yielded by the classifiers are to be used by a company to target marketing efforts. In this thesis work, an emphasis is put on utility measures and how they can be used to evaluate and compare the usefulness of the classifiers for the marketing tas

Innovative approaches in the educational process management of the university with the use of information and educational environment

In our study, we consider one of the innovative approaches to managing the organization of higher education - the process approach, which creates real opportunities for optimizing and adapting management processes in the University to the requirements of all stakeholders (administration, students, faculty, employees). The study was performed on the basis of the Belgorod national research University (BelSU) with the aim of improving the system of management of educational process of the University, determining of efficiency of functioning of information systems in educational subsystem BSU, determining the relationships of staff and teachers to use modern information and communication technologies (ICT), as well as areas of improvement in the management of the educational process using IC

District Newspapers: the Results of Ten Years of Development in the Conditions of Digitalization (on the Example of Publications of the Novosibirsk Region)

Статья поступила в редакцию 27.02.2023 г.В статье рассматривается развитие газет муниципальных районов Новосибирской области и их сайтов за последнее десятилетие. Источниками данных для анализа стали социологические исследования, которые ежегодно проводятся по заказу администрации области. При анализе представленности газет в интернете фиксировались: дата создания домена, количество страниц на сайте, количество посетителей, данные по оптимизации сайтов для работы на десктопе и мобильных устройствах. В ходе работы было выявлено, что за десять лет аудитория печатных номеров сократилась в 1,5–2 раза, причем сильнее всего у газет, доля аудитории которых была наибольшей в своих районах. Параллельно шли процессы освоения нового информационного пространства: создание и развитие сайтов, систематическое обновление их материалов. Сейчас сайты есть у всех рассмотренных газет (за одним исключением), однако их посещаемость невелика: несколько десятков человек в день.The article examines how the newspapers of the municipal districts of the Novosibirsk region have grown in the last decade, what their websites are have developed. The data sources for the analysis were sociological studies, conducted annually by order of the regional administration. When analyzing the representation of newspapers on the Internet, we took into account the following: the date of creation of the domain, the number of pages on the site, the number of visitors, and the data on the optimization of sites for desktop and mobile devices. It was found out, that in ten years the audience of printed issues has decreased by 1.5–2 times. The newspapers with the largest audience lost it most of all. In parallel, there were processes of mastering a new information space, not only creating, but also developing websites, systematically updating materials on them, striving to make them visually attractive. Now all (with one exception) of the analyzed newspapers have websites, but their attendance is low: several dozen people a day

Recently Arrested Adolescents are at High Risk for Sexually Transmitted Diseases

Adolescent offenders may be at high risk for sexually transmitted diseases (STDs). With previous research and interventions focused on incarcerated adolescents, data are needed on STD prevalence and risk factors among newly arrested youth released to the community, a far larger subgroup.Participants were recruited from all arrested youth processed at the Hillsborough County, Florida Juvenile Assessment Center during the last half of 2006 (506 males, 442 females). Participants voluntarily providing urine samples for drug testing as part of standard protocol were also consented to having their specimens split and tested for chlamydia and gonorrhea, using an FDA-approved nucleic acid amplification test.STD prevalence was similar to those previously reported among incarcerated adolescents: 11.5% tested positive for chlamydia, 4.2% for gonorrhea, and 13.2% for either or both infections. Prevalence was significantly higher among females: 19.2% of females had either or both infections compared with 10.5% of males. Prevalence was higher for 17 to 18 year olds (15.2% of males, 25.5% of females), blacks, detained youths, drug users, and those engaged in sexual risk behaviors. Previous STD testing experience was limited.The study indicated that a voluntary STD screening protocol is feasible for arrested youth entering the juvenile justice system, and these offenders are at high risk for STDs. Because most arrested youths are released back to the community, routine testing and treatment of recently arrested youths, and expanded access to risk reduction and prevention programs, can yield substantial public health benefits

Анализ влияния параметров операционного усилителя на характеристики конвертора отрицательного импеданса

The article deals with a low pass op-amp model with high gain at DC and a single-pole frequency response and presents a technique for  simple analysis of negative inductance compensator (NIC) circuits.  Analytical expressions are derived fo r NIC frequency response analysis in case of operational amplifier finite bandwidth. Besides, the ideal NIC circuit comparison results are provided. Calculations show that op-amp  finite bandwidth has impact on NIC impedance at fre quencies 10 times  lower than gain-bandwidth product. The obtained analytical results are  in good agreement with experimental setup measurements of NIC implementation to electrically small antenna impedance matching.Рассмотрено использование операционного усилителя (ОУ) с характеристикой вида фильтра нижних частот, большим коэффициентом усиления по постоянному току и единственным  полюсом в частотной характеристике в качестве компенсатора отрицательной  индуктивности (КОИ) при подключении электрически малоразмерной штыревой антенны  (ЭМША) к нагрузке. Предложена простая методика анализа цепей КОИ. Получены  аналитические выражения для анализа параметров КОИ в зависимости от частоты в случае  использования ОУ с конечной рабочей полосой частот и приведены результаты сравнения с идеальными цепями КОИ.  Результаты показывают, что конечная полоса частот ОУ оказывает влияние на входной  импеданс КОИ на частотах, в 10 раз меньших частоты единичного усиления ОУ. Полученные  аналитические результаты хорошо согласуются с измерениями экспериментального макета, реализующего КОИ для согласования импеданса ЭМША