mathematical model

Mathematical Model of a Multi-Winding Synchronous Machine With Hybrid Excitation

The use of multi-winding or multi-phase synchronous machines makes it possible to improve electromagnetic compatibility with the power supply, ensure better operation in the case of faults in separate power channels, and improve the quality of electromagnetic torque in systems with semiconductor converters. The magnetic flux in hybrid-excited synchronous machines is formed by means of permanent magnets and an excitation winding. Such machines combine the advantages of permanent magnet synchronous machines with the ability to regulate the magnetic flux.

Mathematical modeling and computer simulation of locomotion conditions of vibration-driven robots

This paper investigates the dynamic behavior and locomotion characteristics of vibration-driven robots with wheeled chassis, focusing on the comparison of two types of vibration exciters: a solenoid-type actuator and a centrifugal (inertial) exciter.  The research methodology involves 3D modeling using SolidWorks software to design the robots, numerical modeling in Mathematica software to simulate their motion and predict kinematic characteristics, and computer simulation in SolidWorks Motion software to validate the modeling results.  The robots utilize overrunning clu

SIMULATION AND RESEARCH OF THE SEPARATION OF TWO TYPES OF SUSPENDED PARTICLES IN A DISPERSED MIXTURE UNDER THE INFLUENCE OF AN ACOUSTIC FIELD

A mathematical model of the process of separating suspended microparticles in a dispersed mixture within a 2-branched channel of a microfluidic lab-chip under the influence of an acoustic field has been developed. The model is implemented in the environment of COMSOL Multiphysics, using thermoviscous acoustics, creeping flow, particle tracking in a fluid flow, and fluid-particle interaction multiphysics interfaces.

RESEARCH OF VIBRATION OSCILLATIONS OF MEMS RESONATORS DURING THEIR OPERATION

 A mathematical model has been developed to study the amplitude-frequency characteristics of the resonator beam. Nonlinear mechanics methods were used in the modeling process. The model takes into account the influence of changes in the elastic properties of the beam material on its oscillation amplitude and frequency. To analyze the internal processes in the material, Voigt's and Bolotin's laws were applied.

Mathematical Model of Logistic Regression for Binary Classification. Part 2. Data Preparation, Learning and Testing Processes

This article reviews the theoretical aspects of logistic regression for binary data classification, including data preparation processes, training, testing, and model evaluation metrics.

Requirements for input data sets are formulated, methods of coding categorical data are described, methods of scaling input features are defined and substantiated.

Mathematical Model of Logistic Regression for Binary Classification. Part 1. Regression Models of Data Generalization

In this article, the mathematical justification of logistic regression as an effective and simple to implement method of machine learning is performed.

A review of literary sources was conducted in the direction of statistical processing, analysis and classification of data using the logistic regression method, which confirmed the popularity of this method in various subject areas.

Model and tools of the navigation system between educational institution buildings using augmented reality technology

A problem of navigation within large educational complexes has been identified, which poses a particular challenge for new students, visitors, and staff. It has been established that the implementation of augmented reality technologies considerably enhances the intuitiveness and usability of the navigation system. A comprehensive structural and mathematical model of the navigation system based on augmented reality technologies has been meticulously developed.

Investigation of Changes in Natural Gas Parameters along a Damaged Gas Pipeline

The paper presents a mathematical model of the stationary flow of natural gas in an inclined gas pipeline, which makes it possible to calculate the gas parameters (pressure, temperature, compressibility factor) in every cross-section of gas pipeline. An improved mathematical model is also proposed by the authors, which considers the change in the gas flowrate along the gas pipeline. Complex 1 characterizing the effect of frictional forces and pressure losses and Complex 2 determining the effect of flow velocity were proposed to confirm the need to use an improved mathematical model.

Stability of the medication distribution model in the body as an open system formed by subsystems

In the paper, the spread of medicine (toxin) in the body which is assumed to be an open system carrying out exchange with the environment is considered. The system itself is considered as a combination of two subsystems: blood and muscle. It is shown that the model can be unstable under some conditions and for a certain range of parameters. Solutions obtained with such parameter values do not correspond to the actual amount of the substance during intravenous injections.

USE OF MICROWAVE RADIATION FOR EFFECTIVE PURIFICATION OF WASTEWATER FROM ORGANIC COMPOUNDS

This article is devoted to the problem of using microwave radiation as a potentially effective method of cleaning wastewater from organic compounds. The problem of cleaning wastewater from organic contaminants in the food industry requires highly effective methods since protein compounds in wastewater can cause environmental hazards and complicate the cleaning process.