将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下...将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下,根据系统驱动、系统频响、系统响应间线性映射关系,通过双谱与自谱间的幅频与相位转换,经IFFT(iverse fast Fourier transform)变换生成满足试验控制要求的时域随机驱动信号。最后以一悬臂梁为试件,对其进行双输入、双输出随机振动控制环境模拟试验。试验结果表明:将双谱应用于多点随机振动控制试验中生成时域随机驱动信号的方法是可行有效的,同时也验证了双谱能抑制高斯白噪声的特性,这一点可通过所生成驱动信号的概率密度分布特征曲线(部分满足均匀分布)进行体现。展开更多
A protein motor system driven by sine electric field is investigated. The signal-to-noise ratio (SNR) is derived in the adiabatic limit. The phenomenon of stochastic resonance is found for this protein motor system.
In the paper, we study a linear system driven by O-U noise and give a method which is different from the one stated in Europhys. Lett. 40 (1997) 117. We find the same phenomenon of multiplicative stochastic resonanc...In the paper, we study a linear system driven by O-U noise and give a method which is different from the one stated in Europhys. Lett. 40 (1997) 117. We find the same phenomenon of multiplicative stochastic resonance for the response of the system to the signal as the one found in Europhys. Left. 40 (1997) 117. The merit of our method is that it prevents the complex formulas when making sum from n = 0 to n →∞ as in Europhys. Lett. 40 (1997) 117, which leads to the approximate results of the figures.展开更多
The transition rate and stochastic resonance (SR) of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The expl...The transition rate and stochastic resonance (SR) of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The explicit expressions of the transition rate and the speetrai power amplification (SPA) are obtained, respectively. The effects of the parameter q indicating the departure from the Ganssian noise and the correlation time T of the non-Gaussian noise on the transition rate and the SPA are discussed. Research results show that: (i) The transition rate as a function of the noise strength exhibits a maximum. This maximum for transition rate identifies the phenomenon of entropie resonant activation (ERA), the parameter q and the noise correlation time T weaken the ERA of the system; (ii) The curves of SPA appear a transition from one peak to double-peak, and then to one peak again as the noise correlation time T of non-Gaussian noise increases.展开更多
In this paper, we study the phenomenon of stochastic resonance (SR) in a periodically driven bistable system with correlations between multiplicative and additive white noise terms when there, are two different kind...In this paper, we study the phenomenon of stochastic resonance (SR) in a periodically driven bistable system with correlations between multiplicative and additive white noise terms when there, are two different kinds of time delays existed in the deterministic and fluctuating forces, respectively. Using the small time delay approximation and the theory of signal-to-noise ratio (SNR) in the adiabatic limit, the expression of SNR is obtained. The effects of the delay time T in the deterministic force, and the delay time 8 in the fluctuating force on SNR are discussed. Based on the numerical computation, it is found that: (i) There appears a reentrant transition between one peak and two peaks and then to one peak again in the curve of SNR when the value of the time delay θ is increased. (ii) SR can be realized by tuning the time delay T or 8 with fixed noise, i.e., delay-induced stochastic resonance (DSR) exists.展开更多
The direct current-direct current (DC-DC) converter is designed for 1 T static random access memory (SRAM) used in display driver integrated circuits (ICs), which consists of positive word-line voltage (VpwL),...The direct current-direct current (DC-DC) converter is designed for 1 T static random access memory (SRAM) used in display driver integrated circuits (ICs), which consists of positive word-line voltage (VpwL), negative word-line voltage (VinyL) and half-VDD voltage (VHDo) generator. To generate a process voltage temperature (PVT)-insensitive VpWL and VNWL, a set of circuits were proposed to generate reference voltages using bandgap reference current generators for respective voltage level detectors. Also, a VOWL regulator and a VNWL charge pump were proposed for a small-area and low-power design. The proposed VpwL regulator can provide a large driving current with a small area since it regulates an input voltage (VCI) from 2.5 to 3.3 V. The VmvL charge pump can be implemented as a high-efficiency circuit with a small area and low power since it can transfer pumped charges to VNWL node entirely. The DC-DC converter for 1 T SRAM were designed with 0.11 μm mixed signal process and operated well with satisfactory measurement results.展开更多
Thermal vibration of single-layered graphene sheets (SLGSs) is investigated using plate model together with the law of equi-partition of energy and the molecular dynamics (MD) method based on the condensed-phase Optim...Thermal vibration of single-layered graphene sheets (SLGSs) is investigated using plate model together with the law of equi-partition of energy and the molecular dynamics (MD) method based on the condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) force field.The in-plane stiffness and Poisson ratio of SLGSs are calculated by stretching SLGSs.The effective thickness of SLGSs is obtained by the MD simulations for the thermal vibration of SLGSs through the natural frequency.The root-mean-squared (RMS) amplitudes for SLGSs of differing temperatures and boundary conditions are calculated by the MD,and are compared with the results calculated by the thin plate model together with the law of equi-partition of energy.At the center of SLGSs,the thin plate theory can predict the MD results reasonably well.For the difference of bonding structure of the edge atoms,the deviation between the MD results and plate theory becomes more readily apparent near the edges of SLGSs.展开更多
By constructing proper coupling operators for the integro-differential type Markov generator, we establish the existence of a successful coupling for a class of stochastic differential equations driven by Levy process...By constructing proper coupling operators for the integro-differential type Markov generator, we establish the existence of a successful coupling for a class of stochastic differential equations driven by Levy processes. Our result implies a new Liouville theorem for space-time bounded harmonic functions with respect to the underlying Markov semigroups, and it is sharp for Ornstein-Uhlenbeck processes driven by s-stable Levy processes.展开更多
In this paper we present an L2-theory for a class of stochastic partial differential equations driven by Levy processes. The coefficients of the equations are random functions depending on time and space variables, an...In this paper we present an L2-theory for a class of stochastic partial differential equations driven by Levy processes. The coefficients of the equations are random functions depending on time and space variables, and no smoothness assumption of the coefficients is assumed.展开更多
We consider a class of stochastic Boussinesq equations driven by L6vy processes and establish the uniqueness of its invariant measure. The proof is based on the progressive stopping time technique.
We study a stochastic control system involving both a standard and a fractional Brownian motion with Hurst parameter less than 1/2.We apply an anticipative Girsanov transformation to transform the system into another ...We study a stochastic control system involving both a standard and a fractional Brownian motion with Hurst parameter less than 1/2.We apply an anticipative Girsanov transformation to transform the system into another one,driven only by the standard Brownian motion with coefficients depending on both the fractional Brownian motion and the standard Brownian motion.We derive a maximum principle and the associated stochastic variational inequality,which both are generalizations of the classical case.展开更多
We study tile local linear estimator for tile drift coefficient of stochastic differential equations driven by α-stable Levy motions observed at discrete instants. Under regular conditions, we derive the weak consis-...We study tile local linear estimator for tile drift coefficient of stochastic differential equations driven by α-stable Levy motions observed at discrete instants. Under regular conditions, we derive the weak consis- tency and central limit theorem of the estimator. Compared with Nadaraya-Watson estimator, the local linear estimator has a bias reduction whether the kernel function is symmetric or not under different schemes. A silnu- lation study demonstrates that the local linear estimator performs better than Nadaraya-Watson estimator, especially on the boundary.展开更多
文摘将高阶累积量谱应用于多点随机振动控制环境试验中,生成时域随机驱动信号。通过建立三阶累积量谱(双谱)与自谱间的幅频与相位转换关系,经时域随机驱动信号验证性生成实验,揭示这层关系的存在。其次在多输入多输出线性系统理论假设前提下,根据系统驱动、系统频响、系统响应间线性映射关系,通过双谱与自谱间的幅频与相位转换,经IFFT(iverse fast Fourier transform)变换生成满足试验控制要求的时域随机驱动信号。最后以一悬臂梁为试件,对其进行双输入、双输出随机振动控制环境模拟试验。试验结果表明:将双谱应用于多点随机振动控制试验中生成时域随机驱动信号的方法是可行有效的,同时也验证了双谱能抑制高斯白噪声的特性,这一点可通过所生成驱动信号的概率密度分布特征曲线(部分满足均匀分布)进行体现。
基金The project supported by National Natural Science Foundation of China under Grant No. 10375009, SRF for R0CS, SEM, and K.C. Wong Magna Fund in Ningbo University of China
文摘A protein motor system driven by sine electric field is investigated. The signal-to-noise ratio (SNR) is derived in the adiabatic limit. The phenomenon of stochastic resonance is found for this protein motor system.
基金supported by the Natural Science Foundation of Ningbo in Chinaby K.C. Wong Magna Fund in Ningbo University of China
文摘In the paper, we study a linear system driven by O-U noise and give a method which is different from the one stated in Europhys. Lett. 40 (1997) 117. We find the same phenomenon of multiplicative stochastic resonance for the response of the system to the signal as the one found in Europhys. Left. 40 (1997) 117. The merit of our method is that it prevents the complex formulas when making sum from n = 0 to n →∞ as in Europhys. Lett. 40 (1997) 117, which leads to the approximate results of the figures.
基金Supported by the Natural Science Foundation of Yunnan Province under Grant No. 2010CD031the Key Project of Research Fund of Education Department of Yunnan Province under Grant No. 2001Z011
文摘The transition rate and stochastic resonance (SR) of a Brownian particle moving in a confined system under the presence of entropic barriers are investigated when the system is driven by non-Gaussian noise. The explicit expressions of the transition rate and the speetrai power amplification (SPA) are obtained, respectively. The effects of the parameter q indicating the departure from the Ganssian noise and the correlation time T of the non-Gaussian noise on the transition rate and the SPA are discussed. Research results show that: (i) The transition rate as a function of the noise strength exhibits a maximum. This maximum for transition rate identifies the phenomenon of entropie resonant activation (ERA), the parameter q and the noise correlation time T weaken the ERA of the system; (ii) The curves of SPA appear a transition from one peak to double-peak, and then to one peak again as the noise correlation time T of non-Gaussian noise increases.
基金Supported by the Natural Science Foundation of Yunnan Province under Grant No.08C0235
文摘In this paper, we study the phenomenon of stochastic resonance (SR) in a periodically driven bistable system with correlations between multiplicative and additive white noise terms when there, are two different kinds of time delays existed in the deterministic and fluctuating forces, respectively. Using the small time delay approximation and the theory of signal-to-noise ratio (SNR) in the adiabatic limit, the expression of SNR is obtained. The effects of the delay time T in the deterministic force, and the delay time 8 in the fluctuating force on SNR are discussed. Based on the numerical computation, it is found that: (i) There appears a reentrant transition between one peak and two peaks and then to one peak again in the curve of SNR when the value of the time delay θ is increased. (ii) SR can be realized by tuning the time delay T or 8 with fixed noise, i.e., delay-induced stochastic resonance (DSR) exists.
基金supported by the Second Stage of Brain Korea 21 Projectsfinancially supported by Changwon National University in 2011-2013
文摘The direct current-direct current (DC-DC) converter is designed for 1 T static random access memory (SRAM) used in display driver integrated circuits (ICs), which consists of positive word-line voltage (VpwL), negative word-line voltage (VinyL) and half-VDD voltage (VHDo) generator. To generate a process voltage temperature (PVT)-insensitive VpWL and VNWL, a set of circuits were proposed to generate reference voltages using bandgap reference current generators for respective voltage level detectors. Also, a VOWL regulator and a VNWL charge pump were proposed for a small-area and low-power design. The proposed VpwL regulator can provide a large driving current with a small area since it regulates an input voltage (VCI) from 2.5 to 3.3 V. The VmvL charge pump can be implemented as a high-efficiency circuit with a small area and low power since it can transfer pumped charges to VNWL node entirely. The DC-DC converter for 1 T SRAM were designed with 0.11 μm mixed signal process and operated well with satisfactory measurement results.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11072108)the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No. 201028)+1 种基金Program for New Century Excellent Talents in University (Grant No. NCET-11-0832)the Foundation of Nanjing University Aeronautics and Astronautics
文摘Thermal vibration of single-layered graphene sheets (SLGSs) is investigated using plate model together with the law of equi-partition of energy and the molecular dynamics (MD) method based on the condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) force field.The in-plane stiffness and Poisson ratio of SLGSs are calculated by stretching SLGSs.The effective thickness of SLGSs is obtained by the MD simulations for the thermal vibration of SLGSs through the natural frequency.The root-mean-squared (RMS) amplitudes for SLGSs of differing temperatures and boundary conditions are calculated by the MD,and are compared with the results calculated by the thin plate model together with the law of equi-partition of energy.At the center of SLGSs,the thin plate theory can predict the MD results reasonably well.For the difference of bonding structure of the edge atoms,the deviation between the MD results and plate theory becomes more readily apparent near the edges of SLGSs.
基金supported by National Natural Science Foundation of China(Grant No.11126350)the Programme of Excellent Young Talents in Universities of Fujian(Grant Nos.JA10058,JA11051)
文摘By constructing proper coupling operators for the integro-differential type Markov generator, we establish the existence of a successful coupling for a class of stochastic differential equations driven by Levy processes. Our result implies a new Liouville theorem for space-time bounded harmonic functions with respect to the underlying Markov semigroups, and it is sharp for Ornstein-Uhlenbeck processes driven by s-stable Levy processes.
基金supported by National Science Foundation of US (Grant No. DMS-0906743)the National Research Foundation of Korea (Grant No. 20110027230)
文摘In this paper we present an L2-theory for a class of stochastic partial differential equations driven by Levy processes. The coefficients of the equations are random functions depending on time and space variables, and no smoothness assumption of the coefficients is assumed.
基金supported by National Natural Science Foundation of China (Grant Nos.10971225 and 11101427)Natural Science Foundation of Hunan Province (Grant No. 11JJ3004)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State the Ministry of Education of China
文摘We consider a class of stochastic Boussinesq equations driven by L6vy processes and establish the uniqueness of its invariant measure. The proof is based on the progressive stopping time technique.
基金supported by National Natural Science Foundation of China(Grant No11301560)
文摘We study a stochastic control system involving both a standard and a fractional Brownian motion with Hurst parameter less than 1/2.We apply an anticipative Girsanov transformation to transform the system into another one,driven only by the standard Brownian motion with coefficients depending on both the fractional Brownian motion and the standard Brownian motion.We derive a maximum principle and the associated stochastic variational inequality,which both are generalizations of the classical case.
基金supported by National Natural Science Foundation of China(Grant Nos.11171303 and 11071213)the Specialized Research Fund for the Doctor Program of Higher Education(Grant No.20090101110020)
文摘We study tile local linear estimator for tile drift coefficient of stochastic differential equations driven by α-stable Levy motions observed at discrete instants. Under regular conditions, we derive the weak consis- tency and central limit theorem of the estimator. Compared with Nadaraya-Watson estimator, the local linear estimator has a bias reduction whether the kernel function is symmetric or not under different schemes. A silnu- lation study demonstrates that the local linear estimator performs better than Nadaraya-Watson estimator, especially on the boundary.