scholarly journals High-Frequency Electrodynamics of Slow Moving Media Taking into Account the Specular Reflection

2021 ◽  
Vol 10 (1) ◽  
pp. 6-14
Author(s):  
N. N. Grinchik ◽  
O. V. Boiprav
Keyword(s):  
Mathematical Model ◽  
Difference Scheme ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Specular Reflection ◽  
Propagation Speed ◽  
Proposed Model ◽  
Slow Moving ◽  
Waves Propagation ◽  
Moving Media

The paper presents the results of constructing the physical and mathematical model of high-frequency electromagnetic waves propagation in slowly moving media of finite dimensions, which takes into account the phenomena of specular reflection of these waves. The constructed model is based on formulas designed to determine the speed of electromagnetic waves propagation in slowly moving media of finite dimensions, as well as on equations designed to describe these waves. The advantageous feature of these equations is that they take into account the Fresnel drag coefficient for electromagnetic waves propagation speed. The approach to solving of these equations, as well as the approach to modeling of the process of electromagnetic waves propagation in slowly moving media of finite dimensions, based on the use of a difference scheme, in which the motion of these media is taken into account, is proposed. It has been determined that the proposed model and approaches can be used in solving problems related to the construction of receiving-transmitting paths, as well as in solving problems of aeroacoustics.

scholarly journals Mathematical model of colostrum defrosting in super-high-frequency generator equipped

2021 ◽  
Vol 935 (1) ◽  
pp. 012027
Author(s):  
I Ershova ◽  
M Prosviryakova ◽  
O Mikhailova ◽  
G Novikova ◽  
G Samarin ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Raw Material ◽  
Operating Modes ◽  
High Frequency Electromagnetic Field ◽  
Super High Frequency

Abstract The paper is devoted to development and parameters studying of two-resonator super-high-frequency (SHF) generator based on continuous flow principle of action. It is equipped with two quasi-stationary toroidal resonators; so it allows to separate such processes of cattle colostral milk treatnent as defrosting and heating and thus to ensure both the electromagnetic safety and the high electric field strength. In order to improve efficiency of the cattle colostrum defrosting/heating performed by its exposure to the super-high frequency electromagnetic field, the methodology was developed for the SHF generator designing. It includes, firstly, development & studying of mathematical models based on due consideration of the phase transitions and, secondly, the structural designing of the SHF generator working chamber with examination of its effective operating modes. The mathematical model is proposed of the electromagnetic waves interaction with the raw material (colostral milk) being in different physical states. With aid of the electric field strength control (by the generators power changing) and the gap adjustment in the capacitor part of the resonators (by smooth movement of the common perforated base), it is possible to achieve the equipment capacity up to 170… 200 L/h. The energy expenses are 0.025 (kWh)/kg.

Characteristics Simulation of Ultra-High Frequency Electromagnetic Wave Excited by Equivalent Partical Discharge Mathematical Model in GIS

2014 ◽  
Vol 1070-1072 ◽  
pp. 1138-1143
Author(s):  
Guang Ke Xu ◽  
Wei Wei Zhang ◽  
Zhen Hua Zhu ◽  
Nan Wang ◽  
Fu Qiang Zhao
Keyword(s):  
Mathematical Model ◽  
Electromagnetic Wave ◽  
Frequency Domain ◽  
Time Domain ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Fdtd Method ◽  
Propagation Characteristics ◽  
Ultra High Frequency ◽  
Actual Measure

UHF electromagnetic waves radiated by PD in GIS can range from several hundreds of MHz to several GHz. FDTD method is usually used to simulate the characteristics of the UHF electromagnetic waves. Compared with the traditional ideal Gaussian pulses in simulation, one equivalent PD mathematical model based on the actual measure PD sources was considered to simulate the propagation characteristics. Time domain and frequency domain spectrum of signals excited by the two PD sources were studied to analyze the propagation characteristics. It can draw the conclusions that each insulator detect leads to each electromagnetic and its time domain and frequency domain spectrum. So it is recommended to use equivalent PD mathematical model to simulator the propagation characteristics.

MATHEMATICAL MODEL OF DETERMINING THE DEGREE OF ATMOSPHERIC POLLUTION BY EMISSIONS OF CHEMICAL SUBSTANCES

2018 ◽  
pp. 17-25
Author(s):  
Ekaterina Vadimovna Kusheleva ◽  
Marina Aleksandrovna Barulina ◽  
Aleksey Sergeevich Bogomolov ◽  
Vladimir Andreevich Ivashchenko ◽  
Vadim Alekseevich Kushnikov ◽  
...  
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Difference Scheme ◽  
Conditional Stability ◽  
Atmospheric Pollutant ◽  
Chemical Substances ◽  
Air Contamination ◽  
Proposed Model ◽  
Special Cases ◽  
Pollutant Distribution

The article focuses on the problems of environmental monitoring of atmospheric pollutant distribution and determining air contamination on the controlled areas. In the course of solving the designated problems there has been developed a mathematical model that allows to predict the dynamics of distribution of dangerous chemicals emitted into the atmosphere in the result of emergency, and to determine the change of their concentration in the course of the time. There was built a difference scheme for a numerical solution of the differential equation of turbulent diffusion, and given a proof of its conditional stability both for general and special cases. The developed program product helps to carry out necessary calculations and to demonstrate the dynamics of distributing the tail of atmospheric pollutant. The results of experimental computations confirming the adequacy of the proposed model have been presented.

THE DEVELOPMENT OF THE MATHEMATICAL MODEL OF PREDICTING THE INDICATORS OF ACCREDITATION OF TECHNICAL UNIVERSITIES IN THE RUSSIAN FEDERATION

2017 ◽  
pp. 27-38
Author(s):  
Olga Mikhaylovna Tikhonova ◽  
Alexander Fedorovich Rezchikov ◽  
Vladimir Andreevich Ivashchenko ◽  
Vadim Alekseevich Kushnikov
Keyword(s):  
Mathematical Model ◽  
System Dynamics ◽  
Regression Model ◽  
Oriented Graph ◽  
Real Data ◽  
Educational Process ◽  
Proposed Model ◽  
Linear Differential ◽  
The University ◽  
The Mathematical Model

The paper presents the system of predicting the indicators of accreditation of technical universities based on J. Forrester mechanism of system dynamics. According to analysis of cause-and-effect relationships between selected variables of the system (indicators of accreditation of the university) there was built the oriented graph. The complex of mathematical models developed to control the quality of training engineers in Russian higher educational institutions is based on this graph. The article presents an algorithm for constructing a model using one of the simulated variables as an example. The model is a system of non-linear differential equations, the modelling characteristics of the educational process being determined according to the solution of this system. The proposed algorithm for calculating these indicators is based on the system dynamics model and the regression model. The mathematical model is constructed on the basis of the model of system dynamics, which is further tested for compliance with real data using the regression model. The regression model is built on the available statistical data accumulated during the period of the university's work. The proposed approach is aimed at solving complex problems of managing the educational process in universities. The structure of the proposed model repeats the structure of cause-effect relationships in the system, and also provides the person responsible for managing quality control with the ability to quickly and adequately assess the performance of the system.

A Mathematical Model for the Anaerobic Digestion Process Applied to a Mixture of Night Soil and Septic Tank Sludge

1986 ◽  
Vol 18 (7-8) ◽  
pp. 239-248 ◽  
Author(s):  
Sung Ryong Ha ◽  
Dwang Ho Lee ◽  
Sang Eun Lee
Keyword(s):  
Mathematical Model ◽  
Anaerobic Digestion ◽  
Biomass Concentration ◽  
Gas Production ◽  
Septic Tank ◽  
Volatile Acid ◽  
Hydraulic Residence Time ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Proposed Model

Laboratory scale experiments were conducted to develop a mathematical model for the anaerobic digestion of a mixture of night soil and septic tank sludge. The optimum mixing ratio by volume between night soil and septic tank sludge was found to be 7:3. Due to the high solids content in the influent waste, mixed-liquor volatile suspended solids (MLVSS) was not considered to be a proper parameter for biomass concentration, therefore, the active biomass concentration was estimated based on deoxyribonucleic acid (DNA) concentration in the reactor. The weight ratio between acidogenic bacteria and methanogenic bacteria in the mixed culture of a well-operated anaerobic digester was approximately 3:2. The proposed model indicates that the amount of volatile acid produced and the gas production rate can be expressed as a function of hydraulic residence time (HRT). The kinetic constants of the two phases of the anaerobic digestion process were determined, and a computer was used to simulate results using the proposed model for the various operating parameters, such as BOD5 and volatile acid concentrations in effluent, biomass concentrations and gas production rates. These were consistent with the experimental data.

scholarly journals On the Dragging Trajectory of Anchors in Clay for Merchant Ships

2021 ◽  
Vol 9 (2) ◽  
pp. 118
Author(s):  
Xinqing Zhuang ◽  
Keliang Yan ◽  
Pan Gao ◽  
Yihua Liu
Keyword(s):  
Mathematical Model ◽  
Structural Integrity ◽  
Indirect Measurement ◽  
Test System ◽  
Flow Rule ◽  
Burial Depth ◽  
Proposed Model ◽  
Depth Increase ◽  
Two Parameters ◽  
The Mathematical Model

Anchor dragging is a major threat to the structural integrity of submarine pipelines. A mathematical model in which the mechanical model of chain and the bearing model of anchor were coupled together. Based on the associated flow rule, an incremental procedure was proposed to solve the spatial state of anchor until it reaches the ultimate embedding depth. With an indirect measurement method for the anchor trajectory, a model test system was established. The mathematical model was validated against some model tests, and the effects of two parameters were studied. It was found that both the ultimate embedding depth of a dragging anchor and the distance it takes to reach the ultimate depth increase with the shank-fluke pivot angle, but decrease as the undrained shear strength of clay increases. The proposed model is supposed to be useful for the embedding depth calculation and guiding the design of the pipeline burial depth.

scholarly journals Content Dependent Representation Selection Model for Systems Based on MPEG DASH

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1843
Author(s):  
Jelena Vlaović ◽  
Snježana Rimac-Drlje ◽  
Drago Žagar
Keyword(s):  
Mathematical Model ◽  
Spatial Information ◽  
Relevant Literature ◽  
Video Quality ◽  
Similarity Index ◽  
Video Encoding ◽  
Adaptation Algorithm ◽  
Subjective Testing ◽  
Proposed Model ◽  
The Mathematical Model

A standard called MPEG Dynamic Adaptive Streaming over HTTP (MPEG DASH) ensures the interoperability between different streaming services and the highest possible video quality in changing network conditions. The solutions described in the available literature that focus on video segmentation are mostly proprietary, use a high amount of computational power, lack the methodology, model notation, information needed for reproduction, or do not consider the spatial and temporal activity of video sequences. This paper presents a new model for selecting optimal parameters and number of representations for video encoding and segmentation, based on a measure of the spatial and temporal activity of the video content. The model was developed for the H.264 encoder, using Structural Similarity Index Measure (SSIM) objective metrics as well as Spatial Information (SI) and Temporal Information (TI) as measures of video spatial and temporal activity. The methodology that we used to develop the mathematical model is also presented in detail so that it can be applied to adapt the mathematical model to another type of an encoder or a set of encoding parameters. The efficiency of the segmentation made by the proposed model was tested using the Basic Adaptation algorithm (BAA) and Segment Aware Rate Adaptation (SARA) algorithm as well as two different network scenarios. In comparison to the segmentation available in the relevant literature, the segmentation based on the proposed model obtains better SSIM values in 92% of cases and subjective testing showed that it achieves better results in 83.3% of cases.

The Generation Principle and Mathematical Models of Double-Enveloping Internal Gear Pairs

2015 ◽  
Author(s):  
Xuan Li ◽  
Bingkui Chen ◽  
Yawen Wang ◽  
Guohua Sun ◽  
Teik C. Lim
Keyword(s):  
Mathematical Model ◽  
Load Capacity ◽  
Geometrical Shape ◽  
Gear Pair ◽  
Numerical Examples ◽  
Proposed Model ◽  
General Mathematical Model ◽  
Meshing Characteristics ◽  
Internal Gear ◽  
Tooth Pair

In this paper, the planar double-enveloping method is presented for the generation of tooth profiles of the internal gear pair for various applications, such as gerotors and gear reducers. The main characteristic of this method is the existence of double contact between one tooth pair such that the sealing property, the load capacity and the transmission precision can be significantly improved as compared to the conventional configuration by the single-enveloping theory. Firstly, the generation principle of the planar double-enveloping method is introduced. Based on the coordinate transformation and the envelope theory, the general mathematical model of the double-enveloping internal gear pair is presented. By using this model, users can directly design different geometrical shape profiles to obtain a double-enveloping internal gear pair with better meshing characteristics. Secondly, to validate the effectiveness of the proposed model, specific mathematical formulations of three double-enveloping internal gear pairs which apply circular, parabolic and elliptical curves as the generating curves are given. The equations of tooth profiles and meshing are derived and the composition of tooth profiles is analyzed. Finally, numerical examples are provided for an illustration.

scholarly journals An Optimized Mathematical Model for Items Supplies Planning of a Logistic System

2016 ◽  
Vol 10 (10) ◽  
pp. 133
Author(s):  
Mohammad Ali Nasiri Khalili ◽  
Mostafa Kafaei Razavi ◽  
Morteza Kafaee Razavi
Keyword(s):  
Mathematical Model ◽  
Mixed Integer ◽  
Logistics System ◽  
Proposed Model ◽  
Multiple Objective Decision Making ◽  
System Requirements ◽  
Purchasing Logistics ◽  
The Cost ◽  
The Mathematical Model ◽  
First Time

Items supplies planning of a logistic system is one of the major issue in operations research. In this article the aim is to determine how much of each item per month from each supplier logistics system requirements must be provided. To do this, a novel multi objective mixed integer programming mathematical model is offered for the first time. Since in logistics system, delivery on time is very important, the first objective is minimization of time in delivery on time costs (including lack and maintenance costs) and the cost of purchasing logistics system. The second objective function is minimization of the transportation supplier costs. Solving the mathematical model shows how to use the Multiple Objective Decision Making (MODM) can provide the ensuring policy and transportation logistics needed items. This model is solved with CPLEX and computational results show the effectiveness of the proposed model.

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