In this paper, we investigate the robust exponential stability of a class of fractional order Hopfield neural network with Caputo derivative, and we get some sufficient conditions to guarantee its robust exponential s...In this paper, we investigate the robust exponential stability of a class of fractional order Hopfield neural network with Caputo derivative, and we get some sufficient conditions to guarantee its robust exponential stability. Finally, we use one numerical simulation example to illustrate the correctness and effectiveness of our results.展开更多
In this paper we refer to equations of motion for the single Stokes pulse from the nonlinear optics, called the Stokes pulse system. A fractional-order model with Caputo derivative associated to Stokes pulse system (c...In this paper we refer to equations of motion for the single Stokes pulse from the nonlinear optics, called the Stokes pulse system. A fractional-order model with Caputo derivative associated to Stokes pulse system (called the fractional Stokes pulse system) is proposed. The existence and uniqueness of solution of initial value problem for this fractional system are proved. The dynamic behavior for a special fractional Stokes pulse system is investigated, including: the fractional stability, the stabilization problem using suitable linear controls and the numerical integration based on fractional Euler method.展开更多
This paper studies a finite-time adaptive fractionalorder fault-tolerant control(FTC)scheme for the slave position tracking of the teleoperating cyber physical system(TCPS)with external disturbances and actuator fault...This paper studies a finite-time adaptive fractionalorder fault-tolerant control(FTC)scheme for the slave position tracking of the teleoperating cyber physical system(TCPS)with external disturbances and actuator faults.Based on the fractional Lyapunov stability theory and the finite-time stability theory,a fractional-order nonsingular fast terminal sliding mode(FONFTSM)control law is proposed to promote the tracking and fault tolerance performance of the considered system.Meanwhile,the adaptive fractional-order update laws are designed to cope with the unknown upper bounds of the unknown actuator faults and external disturbances.Furthermore,the finite-time stability of the closed-loop system is proved.Finally,comparison simulation results are also provided to show the validity and the advantages of the proposed techniques.展开更多
In a hollow-core fiber(HCF),light propagates through an air/vacuum core rather than a solid material,resulting in a low thermo-optic coefficient and ability to handle high powers.Here,we demonstrate a laser locked to ...In a hollow-core fiber(HCF),light propagates through an air/vacuum core rather than a solid material,resulting in a low thermo-optic coefficient and ability to handle high powers.Here,we demonstrate a laser locked to a hollow-core fiber reference,which thanks to the low HCF thermal sensitivity,shows long-term stability an order of magnitude better than compact commercially available low-noise lasers.The laser frequency variation within±600 kHz was measured over 50 h.The stability of our proof-of-concept laser is ensured via a strong selfinjection ratio of-15 dB,enabled by the high-power handling and low loss of the hollow-core fiber's resonator.Moreover,our results show appealing performance parameters,including a fractional frequency stability of4×10^(-13)at 1 s averaging time and a Lorentzian component of the linewidth of 0.2 Hz.展开更多
基金Supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2011FQ002)
文摘In this paper, we investigate the robust exponential stability of a class of fractional order Hopfield neural network with Caputo derivative, and we get some sufficient conditions to guarantee its robust exponential stability. Finally, we use one numerical simulation example to illustrate the correctness and effectiveness of our results.
文摘In this paper we refer to equations of motion for the single Stokes pulse from the nonlinear optics, called the Stokes pulse system. A fractional-order model with Caputo derivative associated to Stokes pulse system (called the fractional Stokes pulse system) is proposed. The existence and uniqueness of solution of initial value problem for this fractional system are proved. The dynamic behavior for a special fractional Stokes pulse system is investigated, including: the fractional stability, the stabilization problem using suitable linear controls and the numerical integration based on fractional Euler method.
基金supported by the National Natural Science Foundation of China(61973331,61973257)the National Key Research and Development Plan Programs of China(2018YFB0106101).
文摘This paper studies a finite-time adaptive fractionalorder fault-tolerant control(FTC)scheme for the slave position tracking of the teleoperating cyber physical system(TCPS)with external disturbances and actuator faults.Based on the fractional Lyapunov stability theory and the finite-time stability theory,a fractional-order nonsingular fast terminal sliding mode(FONFTSM)control law is proposed to promote the tracking and fault tolerance performance of the considered system.Meanwhile,the adaptive fractional-order update laws are designed to cope with the unknown upper bounds of the unknown actuator faults and external disturbances.Furthermore,the finite-time stability of the closed-loop system is proved.Finally,comparison simulation results are also provided to show the validity and the advantages of the proposed techniques.
基金Engineering and Physical Sciences Research Council(EP/P030181/1)VACUUM(EP/W037440/1)Technology Agency of the Czech Republic(FW03010171)。
文摘In a hollow-core fiber(HCF),light propagates through an air/vacuum core rather than a solid material,resulting in a low thermo-optic coefficient and ability to handle high powers.Here,we demonstrate a laser locked to a hollow-core fiber reference,which thanks to the low HCF thermal sensitivity,shows long-term stability an order of magnitude better than compact commercially available low-noise lasers.The laser frequency variation within±600 kHz was measured over 50 h.The stability of our proof-of-concept laser is ensured via a strong selfinjection ratio of-15 dB,enabled by the high-power handling and low loss of the hollow-core fiber's resonator.Moreover,our results show appealing performance parameters,including a fractional frequency stability of4×10^(-13)at 1 s averaging time and a Lorentzian component of the linewidth of 0.2 Hz.
