A significant number of recent scientific papers have raised awareness of changes in the biological world of bees, problems with their extinction, and, as a consequence, their impact on humans and the environment. This work relies on precision beekeeping in apiculture and raises the scale of measurement and prediction results using the system we developed, which was designed to cover beehive ecosystem. It is equipped with an IoT modular base station that collects a wide range of parameters from sensors on the hive and a bee counter at the hive entrance. Data are sent to the cloud for storage, analysis, and alarm generation. A time-series forecasting model capable of estimating the volume of bee exits and entrances per hour, which simulates dependence between environmental conditions and bee activity, was devised. The applied mathematical models based on recurrent neural networks exhibited high accuracy. A web application for monitoring and prediction displays parameters, measured values, and predictive and analytical alarms in real time. The predictive component utilizes artificial intelligence by applying advanced analytical methods to find correlation between sensor data and the behavioral patterns of bees, and to raise alarms should it detect deviations. The analytical component raises an alarm when it detects measured values that lie outside of the predetermined safety limits. Comparisons of the experimental data with the model showed that our model represents the observed processes well.

This paper presents the analysis of electrical and dielectric properties of the yttrium-doped nickel ferrite nano-powders synthesized using the co-precipitation method. Impedance and dielectric measurements have been carried out as a function of frequency at different temperatures from 200 to 25 °C in the range of 0.1 kHz–1 MHz. In order to investigate the conduction mechanism and highlight the role of yttrium doping in different concentrations, impedance spectroscopy was employed. The obtained data were analyzed in terms of equivalent circuits made of resistor and capacitor components describing the contributions from different electrical active regions in a material. Further, this study highlights the importance of a single constant phase element (CPE) in the description of dispersion behavior of the impedance response of the investigated samples in the given frequency range. The use of this technique enabled the characterization of grain and grain boundaries contribution in overall conductivity mechanism. The dielectric dispersion nature of all investigated materials is reflected in this study. Very high values of the real part of permittivity at low frequencies are assigned to space-charge polarization. The dependence of the real part of dielectric permittivity values of the yttrium content was also discussed. Doping with yttrium in different concentrations that reflects in different electric and dielectric responses is concluded in this study. The greatest change is noticed for the sample with the minimum dopant content for a x = 0.05 atomic percent share of yttrium. To reveal the potential role of more than one ion contribution to the overall relaxation process in investigated compounds, a modified Debye’s equation was utilized.

This paper presents a comprehensive analysis of the dead-time effects in wireless power transfer systems based on LCC-S topology. In these systems operating at high frequencies, the ratio of dead-time versus the operating period becomes critical, and the dead-time issue can cause certain problems regarding power quality, efficiency, and output voltage ripple. The impact of input quantities such as voltage and switching frequency on the efficiency and output power of the LCC-S-tuned WPT system was also investigated. The optimal combination of these parameters used to achieve the maximum efficiency for a target output power and to set the appropriate value of the dead time were determined by running multiple simulations using the MATLAB R2023b software platform. It was also shown that the output voltage remained unchanged with and without a load and up to 1200 ns of dead-time, which provides a simple implementation of the corresponding mathematical model. In the recommended interval of 600–1500 ns, the influence of the dead-time on the value of the output voltage amplitude is less than 10%. The validity of the proposed method was confirmed through the implementation of the experimental prototype, a 5 kW wireless power transmission system, and the obtained results were in accordance with the simulation results.

Accurate hysteresis models are necessary for modeling of magnetic components of devices such as transformers and motors. This study presents a hysteresis model with a convenient analytical form, based on hypergeometric functions with one free parameter, built upon a class of parameterized curves. The aim of this work is to explore suitability of the presented model for describing major and minor loops, as well as to demonstrate improved agreement between experimental and modeled hysteresis loops. The procedure for generating first order reversal curves is also discussed. The added parameter, introduced into the model, controls the shape of the model curve, especially near saturation. It can be adjusted to provide better agreement between measured and model curves. The model parameters are nonlinearly dependent; therefore, they are determined in a nonlinear curve fitting procedure. The choice of the initial approximation and a suitable set of constraints for the optimization procedure are discussed. The inverse of the model function, required to generate first order reversal curves, cannot be obtained in analytical form. The procedure to calculate the inverse numerically is presented. Performance of the model is demonstrated and verified on experimental data obtained from measurements on construction steel sheets and grain-oriented electrical steel samples.

Connecting theory and practice in teaching is sometimes difficult, as it requires expensive or delicate equipment, thus limiting the teacher to giving demonstrations in which students are passive participants. Numerical mathematics, as an applied discipline, should be taught on real world examples. By using inexpensive Arduino hardware, we can create simple experiments that are easily reproduced by students. Furthermore, the experiments generate tangible data, which can be processed numerically. The choice of the software used for numerical processing is also an important issue. We present several exercises in numerical mathematics that are based on experiments in electrical engineering with Arduino, and show how to turn them into motivational examples. We also present our experiences in teaching using the developed exercises, as well as some important points and conclusions, which stem from discussions with the participating students and teachers.

Современное образование начинает вытеснять традиционное (уроки от учителя к ученику) высокотехнологичным обучением с использованием различных образовательных инструментов и подбором материалов, которые являются эффективными, действенными и привлекательными pagebreak для учащихся. Программное обеспечение динамической геометрии (DGS) сегодня широко используется в преподавании и изучении математики. Такое образовательное программное обеспечение может развиваться несколькими способами, либо надстраивая новые функции, либо добавляя новые функции на поверхности, либо развивая механизм оценки в его ядре. Реализация DGS должна быть простой и модульной. Чтобы добиться развития ядра DGS мы разработали среду программирования для программного обеспечения динамической геометрии SLGeometry с обобщенным функциональным языком и соответствующим механизмом оценки выражений. Механизм действует как фреймворк, в который встроена конкретная семантика в виде кода, аннотированного метаданными. Этот фреймворк преобразует обычный вычислитель дерева выражений в объектно-ориентированный. В то время как другие DG основаны на чисто функциональных оценщиках выражений, наше решение обладает преимуществами более общего, поддерживаемого, понятного, простого в реализации и обеспечивающего естественный способ задания свойств объекта в пользовательском интерфейсе, минимизируя типизацию и синтаксические ошибки. Модульный подход позволяет самостоятельно разрабатывать предметно-ориентированные компоненты, которые легко добавляются в механизм оценки в виде плагинов. Объектно-ориентированный характер фреймворка позволяет разрабатывать автономные единицы, такие как объекты и визуальные элементы, которые инкапсулируют предметную семантику и представляют ее пользователю в виде виртуальных заполнителей для реальных объектов и понятий. В этой статье мы представляем несколько возможных улучшений программного обеспечения динамической геометрии, в первую очередь на платформе, которую мы внедрили. Кроме того, мы обсуждаем преимущества этих функций и их влияние на пользователей/студентов. Подход тестируется на SLGeometry - нашей платформе DGS, разработанной в C# на платформе .NET Framework.