scholarly journals Reduced Order Projective and Hybrid Projective Combination-Combination Synchronization of Four Chaotic Josephson Junctions

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
K. S. Ojo ◽  
A. N. Njah ◽  
O. I. Olusola ◽  
M. O. Omeike
Keyword(s):  
Josephson Junctions ◽  
Communication Systems ◽  
Backstepping Technique ◽  
Neural Encoding ◽  
Third Order ◽  
Reduced Order ◽  
Combination Synchronization ◽  
Response Systems ◽  
System Synchronization ◽  
Synchronization Scheme

This paper investigates the reduced order projective and hybrid projective combination-combination synchronization of four chaotic Josephson junctions consisting of two third order Josephson junctions as the drives and two second order chaotic Josephson junctions as the response systems via active backstepping technique. The investigation confirms the achievement of reduced order projective and hybrid projective combination-combination synchronization among four chaotic Josephson junctions via active backstepping technique. Numerical simulations are validated to show the effectiveness of the synchronization scheme. Reduced order combination-combination synchronization scheme has more significant applications to neural encoding and decoding of information in biological systems and to the security of information transmission in communication systems than the usual one drive system and one response system synchronization scheme.

scholarly journals Compound-combination synchronization of chaos in identical and different orders chaotic systems

2015 ◽  
Vol 25 (4) ◽  
pp. 463-490 ◽  
Author(s):  
K. S. Ojo ◽  
A. N. Njah ◽  
O. I. Olusola
Keyword(s):  
Chaotic Systems ◽  
Initial Conditions ◽  
Sufficient Conditions ◽  
Backstepping Technique ◽  
Third Order ◽  
Combination Synchronization ◽  
Response Systems ◽  
Drive Systems ◽  
Synchronization Scheme ◽  
Insight Into

Abstract This paper proposes a new synchronization scheme called compound-combination synchronization. The scheme is investigated using six chaotic Josephson junctions evolving from different initial conditions based on the drive-response configuration via the active backstepping technique. The technique is applied to achieve compound-combination synchronization of: (i) six identical third order resistive-capacitive-inductive-shunted Josepshon junctions (RCLSJJs) (with three as drive and three as response systems); (ii) three third order RCLSJJs (as drive systems) and three second order resistive-capacitive-shunted Josepshon junctions (RCSJJs (as response systems). In each case, sufficient conditions for global asymptotic stability for compound-combination synchronization to any desired scaling factors are achieved. Numerical simulations are employed to verify the feasibility and effectiveness of the compound-combination synchronization scheme. The result shows that this scheme could be used to vary the junction signal to any desired level and also give a better insight into synchronization in biological systems wherein different organs of different dynamical structures and orders are involved. The scheme could also provide high security in information transmission due to the complexity of its dynamical formulation.

scholarly journals Reduced order hybrid function projective combination synchronization of three Josephson junctions

2014 ◽  
Vol 24 (1) ◽  
pp. 99-113 ◽  
Author(s):  
Kayode. S. Ojo ◽  
Abdulahi N. Njah ◽  
Samuel T. Ogunjo ◽  
Olasunkanmi I. Olusola
Keyword(s):  
Josephson Junction ◽  
Josephson Junctions ◽  
Chaotic Systems ◽  
Second Order ◽  
Backstepping Technique ◽  
Third Order ◽  
Reduced Order ◽  
Combination Synchronization ◽  
Response System ◽  
Hybrid Function

Abstract In this paper, we examine reduced order hybrid function projective combination synchronization of three chaotic systems consisting of: (i) two third chaotic Josephson junctions as drives and one second order chaotic Josephson junction as response system; (ii) one third order chaotic Josephson junction as the drive and two second order chaotic Josephson junctions as the slaves using active backstepping technique. The analytic results confirm the realization of reduced order hybrid function projective combination synchronization using active backstepping technique. Numerical simulations are performed to validate the analytical results.

scholarly journals Low-Complexity Synchronization Scheme with Low-Resolution ADCs

Information ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 313 ◽  
Author(s):  
Liu Jun ◽  
Luo Zhongqiang ◽  
Xiong Xingzhong
Keyword(s):  
Power Consumption ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Offset ◽  
Ultra Wideband ◽  
Timing Synchronization ◽  
Quantization Scheme ◽  
Frequency Offset Estimation ◽  
Low Resolution ◽  
Synchronization Scheme

An important function of next-generation (5G) and beyond mobile communication systems is aim to provide thousand-fold capacity growth and to support high-speed data transmission up to several megabits per second. However, the research community and industries have to face a dilemma of power consumption and hardware design to satisfy the increasing communication requirements. For the purpose of improving the system cost, power consumption, and implementation complexity, a novel scheme of symbol timing and frequency offset estimation with low-resolution analog-to-digital converters (ADCs) based on an orthogonal frequency division multiplexing ultra-wideband (OFDM-UWB) system is proposed in this paper. In our work, we first verified the principle that the autocorrelation of the pseudo-noise (PN) sequences was not affected by low-resolution quantization. With the help of this property, the timing synchronization could be strongly implemented against the influence of low-resolution quantization. Then, the transmitted signal structure and low-resolution quantization scheme under the synchronization scheme were designed. Finally, a frequency offset estimation model with one-bit timing synchronization was established. Theoretical analysis and simulation results corroborate that the performance of the proposed scheme not only approximates to that of the full-resolution synchronization scheme, but also has lower power consumption and computational complexity.

Optical bistable switching in pyran dye-doped polymers

2014 ◽  
Vol 23 (02) ◽  
pp. 1450018 ◽  
Author(s):  
Purnima ◽  
Devendra Mohan
Keyword(s):  
Solid State ◽  
Communication Systems ◽  
Optical Bistability ◽  
Nonlinear Refraction ◽  
Nonlinear Behavior ◽  
Single Mode ◽  
Third Order ◽  
Bistable Switching ◽  
Fabry Perot ◽  
Doped Polymers

In the present frame of work, optical bistability using a Fabry–Perot (FP) cavity containing 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) dye entrapped in poly-methylmethacrylate (PMMA) matrix is experimentally investigated. Optical nonlinear behavior of solid-state samples is studied using a single-mode Q-switched nanosecond Nd:YAG laser operating at 532 nm. Various optical nonlinear parameters such as nonlinear refractive index (n2) and third-order susceptibility (χ3) of the material are numerically estimated from bistability loops. The origin of optically bistable behavior is attributed to photoisomerization-assisted nonlinear refraction phenomenon. It is observed that nonlinear refraction dominates over nonlinear absorption in giving rise to the optical bistability. The study shows that DCM dye entrapped in solid-state matrices are promising candidate for polymer-based optical switches, data processing, and communication systems.

Amplitude-Frequency Response of Superharmonic Resonance of Third Order of Electrostatically Actuated MEMS Cantilever Resonators

2019 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Christopher Reyes
Keyword(s):  
Frequency Response ◽  
Cantilever Beam ◽  
Multiple Scales ◽  
Electrostatic Force ◽  
Beam Theory ◽  
Driving Frequency ◽  
Third Order ◽  
Reduced Order ◽  
Superharmonic Resonance ◽  
Amplitude Frequency Response

Abstract This work deals with amplitude frequency response of MEMS cantilever resonators undergoing superharmonic resonance of third order. The cantilever resonator is parallel to a ground plate and under alternating current (AC) voltage that excites the cantilever into vibrations. The driving frequency of the AC voltage is near one sixth of the first natural frequency of the cantilever beam resulting into superharmonic resonance of third order. The cantilever beam is modeled using Euler-Bernoulli beam theory. The electrostatic force is modeled using Palmer’s formula to include the fringe effect. In order to investigate the amplitude frequency behavior of the system reduced order models (ROMs) are developed. Three methods are used to solve these ROMs they are 1) the method of multiple scales (MMS) for ROM with one mode of vibration, 2) homotopy analysis method (HAM) for ROM with one mode of vibration, and 3) direct numerical integration for 2 modes of vibration Reduced Order Model (2T ROM) producing time responses of the tip of the cantilever resonator. In this work the limitations of MMS and HAM are highlighted when considering large voltage values i.e hard excitations. For large voltage values MMS and HAM cannot accurately predict the amplitude frequency response; the results from 2T ROM time responses disagree significantly with the MMS and HAM solutions. The effect of voltage on the frequency response is investigated. As the voltage values in the system increase the responses shift to lower frequencies and larger amplitudes.

CHAOS AND ROBUST ADAPTIVE SYNCHRONIZATION IN A NONLINEAR EMITTER–RECEIVER SYSTEM

2007 ◽  
Vol 17 (09) ◽  
pp. 3259-3274 ◽  
Author(s):  
F. M. MOUKAM KAKMENI ◽  
SAMUEL BOWONG
Keyword(s):  
Adaptive Observer ◽  
Adaptive Synchronization ◽  
Unknown Parameters ◽  
External Disturbances ◽  
Global Synchronization ◽  
Receiver System ◽  
Lipschitz Constants ◽  
Response Systems ◽  
Robust Adaptive ◽  
Synchronization Scheme

This work studies transitions to chaos and adaptive synchronization of a nonlinear emitter–receiver system in a drive–response framework. Safe bifurcations and explosive bifurcations are observed. A robust adaptive observer-based response system is designed to synchronize the emitter–receiver system with unknown parameters and external disturbances. Lyapunov stability ensures global synchronization between the drive and response systems even if Lipschitz constants on functions matrices and bound on uncertainties are unknown. Computer simulations are provided to illustrate the designed adaptive synchronization scheme.

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