scholarly journals A locally Active Discrete Memristor Model and Its Application in a Hyperchaotic Map

2021 ◽  
Author(s):  
Minglin Ma ◽  
Yang Yang ◽  
Zhicheng Qiu ◽  
Yuexi Peng ◽  
Yichuang Sun ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Engineering Application ◽  
Two Dimensional ◽  
Coexisting Attractors ◽  
Distribution Diagram ◽  
Dynamical Behaviors ◽  
Memristive System ◽  
Definition Of ◽  
First Time ◽  
Lyapunov Exponent Spectrum

Abstract The continuous memristor is a popular topic of research in recent years, however, there is rare discussion about the discrete memristor model, especially the locally active discrete memristor model. This paper proposes a locally active discrete memristor model for the first time and proves the three fingerprints characteristics of this model according to the definition of generalized memristor. A novel hyperchaotic map is constructed by coupling the discrete memristor with a two-dimensional generalized square map. The dynamical behaviors are analyzed with attractor phase diagram, bifurcation diagram, Lyapunov exponent spectrum, and dynamic behavior distribution diagram. Numerical simulation analysis shows that there is significant improvement in the hyperchaotic area, the quasi-periodic area and the chaotic complexity of the two-dimensional map when applying the locally active discrete memristor. In addition, antimonotonicity and transient chaos behaviors of system are reported. In particular, the coexisting attractors can be observed in this discrete memristive system, resulting from the different initial values of the memristor. Results of theoretical analysis are well verified with hardware experimental measurements. This paper lays a great foundation for future analysis and engineering application of the discrete memristor and relevant the study of other hyperchaotic maps.

scholarly journals Hidden Multistability in a Memristor-Based Cellular Neural Network

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Birong Xu ◽  
Hairong Lin ◽  
Guangyi Wang
Keyword(s):  
Neural Network ◽  
Simulation Analysis ◽  
Equilibrium Points ◽  
Cellular Neural Network ◽  
Nonlinear Phenomena ◽  
Hidden Attractors ◽  
Coexisting Attractors ◽  
Dynamical Behaviors ◽  
Circuit Simulations

In this paper, we report a novel memristor-based cellular neural network (CNN) without equilibrium points. Dynamical behaviors of the memristor-based CNN are investigated by simulation analysis. The results indicate that the system owns complicated nonlinear phenomena, such as hidden attractors, coexisting attractors, and initial boosting behaviors of position and amplitude. Furthermore, both heterogeneous multistability and homogenous multistability are found in the CNN. Finally, Multisim circuit simulations are performed to prove the chaotic characteristics and multistability of the system.

Chaos in a Meminductor-Based Circuit

2016 ◽  
Vol 26 (08) ◽  
pp. 1650130 ◽  
Author(s):  
Fang Yuan ◽  
Guangyi Wang ◽  
Peipei Jin ◽  
Xiaoyuan Wang ◽  
Guojin Ma
Keyword(s):  
Lyapunov Exponent ◽  
Equivalent Circuit ◽  
Smooth Curve ◽  
Experimental Results ◽  
Chaotic Oscillator ◽  
Coexisting Attractors ◽  
Dynamical Behaviors ◽  
Equilibrium Set ◽  
Curve Model ◽  
Lyapunov Exponent Spectrum

A smooth curve model of meminductor and its equivalent circuit have been designed, on the condition that the meminductor is commonly unavailable. The equivalent circuit can be used for breadboard experiments for various application circuit designs of meminductor. Based on the meminductor, a new chaotic oscillator is proposed. The dynamical behaviors of the oscillator are investigated, including equilibrium set, Lyapunov exponent spectrum, bifurcations and dynamical map of the system. Particularly, the amplitude controlling is analyzed and coexisting attractors are found for conditions of different parameters. Furthermore, the experimental results are given to confirm the correction of the proposed meminductor model and the meminductor-based oscillator.

A Simple Nonautonomous Hidden Chaotic System with a Switchable Stable Node-Focus

2019 ◽  
Vol 29 (12) ◽  
pp. 1950168 ◽  
Author(s):  
Bocheng Bao ◽  
Jiaoyan Luo ◽  
Han Bao ◽  
Chengjie Chen ◽  
Huagan Wu ◽  
...  
Keyword(s):  
Phase Plane ◽  
Value Function ◽  
Analog Circuit ◽  
Nonautonomous System ◽  
Stable Node ◽  
Two Dimensional ◽  
Coexisting Attractors ◽  
Absolute Value ◽  
Dynamical Behaviors ◽  
Hidden Oscillations

This paper presents a simple two-dimensional nonautonomous system, which possesses piecewise linearity constructed by a simple absolute value function. The nonautonomous system has only one switchable equilibrium state with a stable node-focus in the considered control parameter region but can generate periodic, chaotic and coexisting attractors. Therefore, the presented simple two-dimensional nonautonomous system always operates with hidden oscillations, which is not similar to any example reported in the literature. Furthermore, specific hidden dynamical behaviors are numerically disclosed by employing one-dimensional and two-dimensional bifurcation plots, phase plane plots, Poincaré mappings, local attraction basins, and complexity plots. In addition, by utilizing the circuit module of the absolute value function, a multiplierless analog circuit is designed, based on which breadboard experiments are performed to validate the numerically simulated phase plane plots of coexisting attractors.

Numerical Simulation of New Class-Honeycomb Sandwich Structure's Core

2013 ◽  
Vol 834-836 ◽  
pp. 1601-1606
Author(s):  
Xiang Li ◽  
Li Cheng Yu ◽  
You Hui Zhou ◽  
Yang Li ◽  
Xun Zhang
Keyword(s):  
Numerical Simulation ◽  
Sandwich Structure ◽  
Simulation Analysis ◽  
Engineering Application ◽  
Efficient Energy ◽  
New Class ◽  
Honeycomb Sandwich ◽  
Theoretical Significance ◽  
First Time ◽  
Honeycomb Sandwich Structure

As the sandwich structure materials extensively used in the engineering field, the existing sandwich structure materials can not meet the requirements of engineering design gradually. New sandwich structural materials with efficient, energy-saving and easy processing need to be developed urgently. Relying on the mature research results now on honeycomb sandwich structure, the class-honeycomb sandwich structure is put forward for the first time, meanwhile, innovate configuration in the structure. Based on this, the paper analyzes the mechanics properties of the structure and the results showed that the new class-honeycomb sandwich structures mechanics properties have improved greatly compared with the original hexagonal honeycomb sandwich structure. And also simulation analysis was carried out on the cores structure. The validity of the equivalent elastic constant is confirmed through the theoretical analysis and simulation analysis. For this reason, it has great theoretical significance and engineering application value.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

scholarly journals Influence of a Standing Wave Flow-Field on the Dynamics of a Spray Diffusion Flame

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
J. Barry Greenberg ◽  
David Katoshevski
Keyword(s):  
Liquid Phase ◽  
Flow Field ◽  
Standing Wave ◽  
Diffusion Flame ◽  
Stokes Number ◽  
Flame Height ◽  
Wave Flow ◽  
Two Dimensional ◽  
Governing Equations ◽  
First Time

A theoretical investigation of the influence of a standing wave flow-field on the dynamics of a laminar two-dimensional spray diffusion flame is presented for the first time. The mathematical analysis permits mild slip between the droplets and their host surroundings. For the liquid phase, the use of a small Stokes number as the perturbation parameater enables a solution of the governing equations to be developed. Influence of the standing wave flow-field on droplet grouping is described by a specially constructed modification of the vaporization Damkohler number. Instantaneous flame front shapes are found via a solution for the usual Schwab–Zeldovitch parameter. Numerical results obtained from the analytical solution uncover the strong bearing that droplet grouping, induced by the standing wave flow-field, can have on flame height, shape, and type (over- or under-ventilated) and on the existence of multiple flame fronts.

scholarly journals Multi-objective parametrization of interatomic potentials for large deformation pathways and fracture of two-dimensional materials

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xu Zhang ◽  
Hoang Nguyen ◽  
Jeffrey T. Paci ◽  
Subramanian K. R. S. Sankaranarayanan ◽  
Jose L. Mendoza-Cortes ◽  
...  
Keyword(s):  
Large Deformation ◽  
Functional Form ◽  
Principal Component ◽  
Interatomic Potentials ◽  
Two Dimensional ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Two Dimensional Materials ◽  
Definition Of

AbstractThis investigation presents a generally applicable framework for parameterizing interatomic potentials to accurately capture large deformation pathways. It incorporates a multi-objective genetic algorithm, training and screening property sets, and correlation and principal component analyses. The framework enables iterative definition of properties in the training and screening sets, guided by correlation relationships between properties, aiming to achieve optimal parametrizations for properties of interest. Specifically, the performance of increasingly complex potentials, Buckingham, Stillinger-Weber, Tersoff, and modified reactive empirical bond-order potentials are compared. Using MoSe2 as a case study, we demonstrate good reproducibility of training/screening properties and superior transferability. For MoSe2, the best performance is achieved using the Tersoff potential, which is ascribed to its apparent higher flexibility embedded in its functional form. These results should facilitate the selection and parametrization of interatomic potentials for exploring mechanical and phononic properties of a large library of two-dimensional and bulk materials.

scholarly journals Solving puzzles in deformed JT gravity: phase transitions and non-perturbative effects

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Clifford V. Johnson ◽  
Felipe Rosso
Keyword(s):  
Phase Structure ◽  
Scalar Potential ◽  
String Equation ◽  
Two Dimensional ◽  
Leading Order ◽  
Classical Analysis ◽  
First Order ◽  
First Order Phase Transition ◽  
Definition Of ◽  
First Order Phase

Abstract Recent work has shown that certain deformations of the scalar potential in Jackiw-Teitelboim gravity can be written as double-scaled matrix models. However, some of the deformations exhibit an apparent breakdown of unitarity in the form of a negative spectral density at disc order. We show here that the source of the problem is the presence of a multi-valued solution of the leading order matrix model string equation. While for a class of deformations we fix the problem by identifying a first order phase transition, for others we show that the theory is both perturbatively and non-perturbatively inconsistent. Aspects of the phase structure of the deformations are mapped out, using methods known to supply a non-perturbative definition of undeformed JT gravity. Some features are in qualitative agreement with a semi-classical analysis of the phase structure of two-dimensional black holes in these deformed theories.

scholarly journals New Challenges for Biobanks: Accreditation to the New ISO 20387:2018 Standard Specific for Biobanks

BioTech ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 13
Author(s):  
Pasquale De Blasio ◽  
Ida Biunno
Keyword(s):  
Performance Monitoring ◽  
Quality Management System ◽  
Internal Audit ◽  
Accreditation Body ◽  
Accreditation Process ◽  
Testing Facility ◽  
Collection Data ◽  
Definition Of ◽  
First Time ◽  
Operational Aspects

Background: The emergence of “multi-omics” and “multi-parametric” types of analysis based on a high number of biospecimens enforces the use of a great number of high-quality “Biological Materials and Associated Data” (BMaD). To meet the demands of biomedical research, several Biological Resource Centers (BRCs) or Biobanks world-wide have implemented a specific Quality Management System (QMS) certified ISO 9001:2015 or accredited by CAP9 ISO 20387:2018. For the first time, ISO, with the support of several Biobanking experts, issued the ISO 20387:2018 which is the first ISO norm specific for Biobanks. The fundamental difference with present certification/accreditation standards is that the ISO 20387:2018 focuses not only on the operational aspects of the Biobank, but also on the “competence of the Biobank to carry our specific Biobanking tasks”. Methods: The accreditation process for ISO 20387:2018 required the definition of: (1) objectives, goals and organizational structure of the Biobank, including procedures for governance, confidentiality and impartiality policies; (2) standard operating procedures (SOPs) of all activities performed, including acquisition, analysis, collection, data management, distribution, preparation, preservation, testing facility and equipment maintenance, calibration, and monitoring; (3) procedures for control of documents and records, the identification of risks and opportunities, improvements, corrective actions, nonconforming records and evaluation of external providers (4) an internal audit and management reviews, verification of QMS performance, monitoring of quality objectives and personnel qualification and competency in carrying out specific Biobanking tasks. Results: The accreditation process is performed by an independent authorized organization which certifies that all processes are performed according to the QMS, and that the infrastructure is engineered and managed according to the GDP and/or GMP guidelines. Conclusion: Accreditation is given by an accreditation body, which recognizes formally that the Biobank is “competent to carry out specific Biobanking tasks”.

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