scholarly journals On a new four-dimensional model of memristor-based chaotic circuit in the context of nonsingular Atangana–Baleanu–Caputo operators

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Chernet Tuge Deressa ◽  
Sina Etemad ◽  
Shahram Rezapour
Keyword(s):  
System Analysis ◽  
Phase Portraits ◽  
Banach Fixed Point Theorem ◽  
Memory Element ◽  
System A ◽  
Trivial Equilibrium ◽  
Computational Circuits ◽  
Parameter Values ◽  
The Given

AbstractA memristor is naturally a nonlinear and at the same time memory element that may substitute resistors for next-generation nonlinear computational circuits that can show complex behaviors including chaos. A four-dimensional memristor system with the Atangana–Baleanu fractional nonsingular operator in the sense of Caputo is investigated. The Banach fixed point theorem for contraction principle is used to verify the existence–uniqueness of the fractional representation of the given system. A newly developed numerical scheme for fractional-order systems introduced by Toufik and Atangana is utilized to obtain the phase portraits of the suggested system for different fractional derivative orders and different parameter values of the system. Analysis on the local stability of the fractional model via the Matignon criteria showed that the trivial equilibrium point is unstable. The dynamics of the system are investigated using Lyapunov exponents for the characterization of the nature of the chaos and to verify the dissipativity of the system. It is shown that the supposed system is chaotic and it is significantly sensitive to parameter variation and small initial condition changes.

scholarly journals Simulation for determining the rod pump system parameter values using finite difference method

2021 ◽  
Vol 22 (1) ◽  
pp. 137
Author(s):  
Erwani Merry Sartika ◽  
Arief Darmawan
Keyword(s):  
Wave Equation ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Difference Method ◽  
System Analysis ◽  
Tuning Parameter ◽  
Pump System ◽  
System A ◽  
Artificial Lift ◽  
Parameter Values

<p>Lifting <span>petroleum to the surface requires a mechanism called an artificial lift. This mechanism is useful for increasing the flow of fluids from a well. One that uses this method is the rod pump. The rod pump system needed the appropriate design (through the determination of the value of the parameters that affect) so that the pump runs optimally. But changing the appropriate design in real terms is not economically and time-efficient. The ideal rod pump system analysis procedure is to take downhole data (in the well) which is commonly called a pump card. A pump card calculation simulation is needed to efficiently analyze the rod pump system. The wave equation can describe the model of the rod pump system. A simulation of pump data calculation is performed using the finite difference method for the wave equation solution. Through the process of tuning parameter values using trial and error methods, the steps of tuning the parameter value of the rod pump system are proposed in this paper. For further research, a pump card calculation method based on a surface card can be developed to efficiently analyze the rod pump.</span></p>

scholarly journals On a Memristor-Based Hyperchaotic Circuit in the Context of Nonlocal and Nonsingular Kernel Fractional Operator

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Shahram Rezapour ◽  
Chernet Tuge Deressa ◽  
Sina Etemad
Keyword(s):  
Fractional Order ◽  
Approximate Solutions ◽  
Order System ◽  
Banach Fixed Point Theorem ◽  
Dimensional System ◽  
Hyperchaotic System ◽  
Memory Element ◽  
Trivial Equilibrium ◽  
Uniqueness Of The Solution ◽  
Order Change

Memristor is a nonlinear and memory element that has a future of replacing resistors for nonlinear circuit computation. It exhibits complex properties such as chaos and hyperchaos. A five-dimensional memristor-based circuit in the context of a nonlocal and nonsingular fractional derivative is considered for analysis. The Banach fixed point theorem and contraction principle are utilized to verify the existence and uniqueness of the solution of the five-dimensional system. A numerical method developed by Toufik and Atangana is used to get approximate solutions of the system. Local stability analysis is examined using the Matignon fractional-order stability criteria, and it is shown that the trivial equilibrium point is unstable. The Lyapunov exponents for different fractional orders exposed that the nature of the five-dimensional fractional-order system is hyperchaotic. Bifurcation diagrams are obtained by varying the fractional order and two of the parameters in the model. It is shown using phase-space portraits and time-series orbit figures that the system is sensitive to derivative order change, parameter change, and small initial condition change. Master-slave synchronization of the hyperchaotic system was established, the error analysis was made, and the simulation results of the synchronized systems revealed a strong correlation among themselves.

scholarly journals THE HYPOTHESIS TEST OF COVARIATION FUNCTIONS OF QUASIPERIODIC PROCESSES SYSTEMS REPRESENTED BY CYLINDRICAL IMAGE MODELS

2020 ◽  
Vol 62 (4) ◽  
pp. 93-102
Author(s):  
Viktor R. Krasheninnikov ◽  
◽  
Iulia E. Kuvaiskova ◽  
Olga E. Malenova ◽  
Aleksei Iu. Subbotin ◽  
...  
Keyword(s):  
Time Series ◽  
Hypothesis Test ◽  
Random Processes ◽  
Model Parameters ◽  
Sea Waves ◽  
Process Systems ◽  
System A ◽  
Image Models ◽  
Parameter Values ◽  
The Given

The generally accepted mathematical model of a wide variety of natural, technical, economic and other objects that exist in time are random processes, for example sea waves, wind, vibrations of engines and hydraulic units, biorhythms, etc. An object is usually described by several parameters, that is a system of random processes or time series. The processes occurring in many objects have a form close to periodic – quasiperiodic, namely there is a periodicity with an element of unpredictability, for example speech sounds, vibrations of various technical objects, daily temperature fluctuations, etc. In order to formulate the problems of processing the quasiperiodic process systems, their mathematical models are required. For this purpose, authors propose models in which the processes are presented in the form of spiral sweeps on autoregressive cylindrical images. A suitable set of parameter values for these models provides a given degree of quasiperiodicity of individual processes and the given covariance relationships between the processes of the system. A criterion is proposed for testing the hypotheses about the correspondence of the observed system of time series to their model of the described type. The authors provide the examples of the application of this criterion with an analysis of the sensitivity to deviations of the model parameters from the expected ones are given.

Neurochemistry of L-Glutamate Transport in the CNS: A Review of Thirty Years of Progress

2001 ◽  
Vol 66 (9) ◽  
pp. 1315-1340 ◽  
Author(s):  
Vladimir J. Balcar ◽  
Akiko Takamoto ◽  
Yukio Yoneda
Keyword(s):  
Molecular Biology ◽  
Glutamate Transport ◽  
Mammalian Brain ◽  
Activity Data ◽  
System A ◽  
Recent Developments ◽  
The Central Nervous System ◽  
Health And Disease ◽  
Disease Analysis

The review highlights the landmark studies leading from the discovery and initial characterization of the Na+-dependent "high affinity" uptake in the mammalian brain to the cloning of individual transporters and the subsequent expansion of the field into the realm of molecular biology. When the data and hypotheses from 1970's are confronted with the recent developments in the field, we can conclude that the suggestions made nearly thirty years ago were essentially correct: the uptake, mediated by an active transport into neurons and glial cells, serves to control the extracellular concentrations of L-glutamate and prevents the neurotoxicity. The modern techniques of molecular biology may have provided additional data on the nature and location of the transporters but the classical neurochemical approach, using structural analogues of glutamate designed as specific inhibitors or substrates for glutamate transport, has been crucial for the investigations of particular roles that glutamate transport might play in health and disease. Analysis of recent structure/activity data presented in this review has yielded a novel insight into the pharmacological characteristics of L-glutamate transport, suggesting existence of additional heterogeneity in the system, beyond that so far discovered by molecular genetics. More compounds that specifically interact with individual glutamate transporters are urgently needed for more detailed investigations of neurochemical characteristics of glutamatergic transport and its integration into the glutamatergic synapses in the central nervous system. A review with 162 references.

Characterization of synthesized xBaO-(40-x)Li2O-60B2O3 glass system: a multi-dimensional research on optical and physical properties

2021 ◽  
Author(s):  
A. M. A. Mostafa ◽  
E. F. El Agammy ◽  
M. Al-Zaibani ◽  
R. Ramadan ◽  
Shams A. M. Issa ◽  
...  
Keyword(s):  
Physical Properties ◽  
Glass System ◽  
System A

A network thermodynamic model of salt and water flow across the kidney proximal tubule

1978 ◽  
Vol 235 (6) ◽  
pp. F638-F648 ◽  
Author(s):  
S. R. Thomas ◽  
D. C. Mikulecky
Keyword(s):  
Proximal Tubule ◽  
Water Flow ◽  
Thermodynamic Model ◽  
Circuit Simulation ◽  
Basolateral Membrane ◽  
Kidney Proximal Tubule ◽  
Network Analyses ◽  
Pump Rate ◽  
Parameter Values ◽  
The Given

This network thermodynamic model of kidney proximal tubule epithelium treats coupled salt and water flow across each component membrane of the epithelium. We investigate the effects of various relative internal parameter values on the concentration of transepithelial flow, the concentrations in the cell and interspace, and the distribution of flows between cellular and paracellular routes. Best fit is obtaine if the apical and basolateral membrane reflection coefficients (or) are equal. The measured transepithelial filtration coefficient, Lp, is a function not only of the component Lps but also of the internal concentrations, or's, and permeabilities. For the given system topology (i.e., connectedness), parameters of component membranes must be within a narrow range to be consistent with experimental results. The dependence of the concentration of transported fluid on the balance between the solute pump rate and the transepithelial volume flow driving force is shown. This has implications for the effects of peritubular or lumen oncotic pressure on salt and water flow. With Appendix B of this paper and a user's guide for a circuit-simulation package (e.g., SPICE or PCAP) the reader can perform similar network analyses of transport models himself.

Structural characterization of two K2SnX(PO4)3 (X=Fe,Yb) with langbeinite structure

2006 ◽  
Vol 21 (3) ◽  
pp. 214-219 ◽  
Author(s):  
Abderrahim Aatiq ◽  
Btissame Haggouch ◽  
Rachid Bakri ◽  
Youssef Lakhdar ◽  
Ismael Saadoune
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Cell Parameter ◽  
Rietveld Analysis ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Octahedral Sites ◽  
Parameter Values

Structures of two K2SnX(PO4)3(X=Fe,Yb) phosphates, obtained by conventional solid state reaction techniques at 950 °C, were determined at room temperature by X-ray powder diffraction using Rietveld analysis. The two materials exhibit the langbeinite-type structure (P213 space group, Z=4). Cubic unit cell parameter values are: a=9.9217(4) Å and a=10.1583(4) Å for K2SnFe(PO4)3 and K2SnYb(PO4)3, respectively. Structural refinements show that the two crystallographically independent octahedral sites (of symmetry 3) have a mixed Sn∕X (X=Fe,Yb) population although ordering is stronger in the Yb phase than in the Fe phase.

Kleinian characterization of asymptotic symmetries of real general relativity

1993 ◽  
Vol 441 (1913) ◽  
pp. 465-471 ◽  
Keyword(s):  
General Relativity ◽  
Automorphism Group ◽  
Group Action ◽  
Radon Transform ◽  
Symmetry Groups ◽  
Asymptotic Symmetry ◽  
The Real ◽  
The Given ◽  
Asymptotic Symmetries

According to Klein’s Erlanger programme, one may (indirectly) specify a geometry by giving a group action. Conversely, given a group action, one may ask for the corresponding geometry. Recently, I showed that the real asymptotic symmetry groups of general relativity (in any signature) have natural ‘projective’ classical actions on suitable ‘Radon transform’ spaces of affine 3-planes in flat 4-space. In this paper, I give concrete models for these groups and actions. Also, for the ‘atomic’ cases, I give geometric structures for the spaces of affine 3-planes for which the given actions are the automorphism group.

scholarly journals VILNIUS ADVANCED-SURFACE MOVEMENT GUIDANCE AND CONTROL SYSTEM (A-SMGCS) SAFETY OBJECTIVES / VILNIAUS AERODROMO AUTOMATIZUOTOS ANTŽEMINIO EISMO STEBĖJIMO IR KONTROLĖS SISTEMOS SAUGOS TIKSLŲ ANALIZĖ

Aviation ◽  
2012 ◽  
Vol 16 (4) ◽  
pp. 130-135
Author(s):  
Vaidotas Kondroška ◽  
Jonas Stankūnas
Keyword(s):  
Control System ◽  
System Analysis ◽  
Flight Safety ◽  
Frequency Of Occurrence ◽  
Surface Movement ◽  
Safety Requirements ◽  
Methods Of Determination ◽  
Guidance And Control ◽  
System A ◽  
And Control

This work reviews the innovative and progressive methods of determination and analysis of safety objectives using Vilnius A-SMGCS example. The aim of the analysis is to determine how failures in this system could affect flight safety in Vilnius aerodrome. Identified safety objectives will limit the frequency of occurrence of hazards enough for the associated risk to be acceptable, and will ensure that appropriate mitigation means are reflected subsequently as Safety Requirements for the system. Analysis reflects aspects of A-SMGCS Safety objectives, which should be taken into consideration. Santrauka Darbe apžvelgiami progresyvūs saugos tikslų analizės metodai pagal Vilniaus aerodromo automatizuotos antžeminio eismo stebėjimo ir kontrolės sistemos veiklos pavyzdį. Analizuojama, kaip šios sistemos sutrikimai gali paveikti skrydžių saugą Vilniaus aerodrome. Remiantis galimų pavojų skrydžių saugai analize, tyrime nustatyti saugos tikslai, pagal kuriuos vėliau bus numatomos riziką mažinančios priemonės (galimų pavojų neutralizavimui ar kylančios rizikos sumažinimui iki priimtino lygio). Straipsnyje pateikiami veiksniai, kuriuos reikėtų įvertinti nustatant aerodromo automatizuotos antžeminio eismo stebėjimo ir kontrolės sistemos saugos tikslus.

Effects of the Cooling Rate on the Acoustic Properties of Pb-10Sn Solder

2012 ◽  
Vol 729 ◽  
pp. 356-360
Author(s):  
Endre Harkai ◽  
Tamás Hurtony ◽  
Péter Gordon
Keyword(s):  
Sound Velocity ◽  
Cooling Rate ◽  
Acoustic Microscopy ◽  
Acoustic Properties ◽  
Scanning Acoustic Microscopy ◽  
Cooling Rates ◽  
Reliability Parameters ◽  
Microscopy Characterization ◽  
The Given

Microhardness and sound velocity were measured in case of differently prepared solder samples. The used Pb-10Sn solder samples were melted then cooled down applying different cooling rates. These procedures caused variant microstructure thus different microhardness and sound velocity values. The sound velocity was measured by means of scanning acoustic microscopy. Characterization of solder materials by acoustic microscopy gives the possibility to non-destructively estimate mechanical and reliability parameters of the given material.

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