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1.
Based on numerical modelling, we obtain solutions for the direct and inverse problems of waveguide light scattering by a stationary statistical nanometer-scale surface roughness in the presence of additive white noise. It is shown that the procedure developed earlier for processing far-zone scattering data (or data on the equivalent Fourier plane) yileds sufficient information on the statistical characteristics of surface roughness even for a very low level of the signal-to-noise ratio (SNR1). In the case of given noise with SNR1, the developed algorithm makes it possible to determine, within the framework of model calculations, the subwavelength correlation radii /20-/30 of the roughness with error no greater than 10-30% and the rms roughness height 50 with error less than 35%. 相似文献
2.
The stochastic resonance (SR) is studied in an overdamped linear system driven by multiplicative and additive noise when the additive noise is a linear combination of an asymmetric dichotomous noise and its square. The exact expressions are obtained for the first two moments and the correlation function and the SR phenomenon appeared. There are three different forms of SR: the bona fide SR, the conventional SR and SR in the broad sense. Moreover, the asymmetry of multiplicative noise has different effect on signal-to-ratio (SNR) for the first two different forms of SR and the effects of multiplicative noise and additive noise on SNR are different. 相似文献
3.
Stochastic resonance (SR) in an over-damped linear system subjected to an excitation of bias signal modulated noise with multiplicative and additive noises is investigated. We obtain the exact expressions of the first two moments and the signal-to-noise ratio (SNR) of the output by using linear-response theory. The SNR depends non-monotonically on the intensity and the correlation time of multiplicative noise, the correlation time of additive noise, the intensity of the cross noise between multiplicative and additive noise, as well as the external field frequency. The conventional SR, the SR in a broad sense and the bona fide SR are found in the system. The influences of the asymmetries of multiplicative and additive noise, the correlation rate of the cross noise, the intensity of additive noise, the amplitude of signal and the bias on the SNR are analyzed. Moreover, we pointed out that SR can be realized by tuning the system parameter with fixed noise, i.e., parameter-induced stochastic resonance (PSR) exists. 相似文献
4.
Stochastic resonance in a bias linear system with multiplicative and additive noise 总被引:7,自引:0,他引:7
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In this paper, the stochastic resonance in a bias linear system
subjected multiplicative
and additive dichotomous noise is investigated. Using the linear-response
theory and the properties of the dichotomous noise, this paper finds
the exact expressions
for the first two moments and the signal-to-noise ratio
(SNR). It is shown that the SNR is a non-monotonic function of the
correlation time of the multiplicative and additive noise, and it varies
non-monotonously with the intensity and asymmetry of the multiplicative
noise as well as the external field frequency. Moreover, the SNR depends on
the system bias, the intensity of the cross noise between the multiplicative
and additive noise, and the strength and asymmetry of the additive noise. 相似文献
5.
Stochastic resonance in linear system driven by multiplicative noise and additive quadratic noise
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In this paper the stochastic resonance (SR) is studied in an overdamped linear system
driven by multiplicative noise and additive quadratic noise. The exact
expressions are obtained for the first two moments and the correlation
function by using linear response and the properties of the dichotomous noise.
SR phenomenon exhibits in the linear system. There are three different forms
of SR: the bona fide SR, the conventional SR and SR in the broad sense.
Moreover, the effect of the asymmetry of the multiplicative noise on the
signal-to-noise ratio (SNR) is different from that of the additive noise and
the effect of multiplicative noise and additive noise on SNR is different. 相似文献
6.
7.
8.
9.
Stochastic resonance in a time-delayed mono-stable system with correlated multiplicative and additive white noise
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This paper considers the stochastic resonance for a time-delayed mono-stable system, driven by correlated multiplicative and additive white noise. It finds that the output signal-to-noise ratio (SNR) varies non-monotonically with the delayed times. The SNR varies non-monotonically with the increase of the intensities of the multiplicative and additive noise, with the increase of the correlation strength between the two noises, as well as with the system parameter. 相似文献
10.
11.
Detection of binary images in noise is considered in the light of statistical detection theory, with particular reference to information storage systems. The different disturbances are classified into system noise and transparency noise. The receiver operating characteristics (ROC) have been obtained when the scanned binary image is corrupted by additive white Gaussian noise and multiplicative speckle. It is shown that improvement in ROC with signal-to-noise ratio (SNR) is less pronounced in the presence of speckle. 相似文献
12.
Stochastic resonance in a bistable system with coloured correlation between additive and multiplicative noise
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The phenomenon of stochastic resonance (SR) in a bistable nonlinear system with coupling between additive and multiplicative noises is investigated when the correlation between two noise terms is coloured. It is found that the signal-to-noise ratio (SNR) of the system is affected not only by the coupling strength λ between two noise terms, but also by the noise correlation time τ. The SNR is changed from a single peak, to two peaks with a dip, and then to a monotonically decreasing function with noise strength. The dependence of the SR on the initial conditions is entirely caused by the coupling strength λ between two noise terms. 相似文献
13.
C. H. Zeng A. L. Gong C. P. Zeng L. R. Nie 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,62(2):219-225
The stochastic resonance (SR) phenomenon in an overdamped bistable
system with multiplicative and additive noise is investigated. The
signal-to-noise ratio (SNR) is calculated when two types of
modulation signal are added to the system. The effects of the
intensities, the frequencies and relative phase shift of two types
of modulation signal on the SNR are discussed, respectively.
Research results show that: (i) the intensities of two types of
modulation signal can enhance the maximum in the SNR as a function
of the noise intensity, and the frequencies can restrain it; (ii)
the additive modulation signal can enhance the maximum in the SNR as
a function of the noise intensity in comparison with the
multiplicative modulation signal; (iii) when both modulation
frequencies are equal, the SNR as a function of the relative phase
shift exhibits multiple maxima. The multiple maxima in the SNR
identifies the characteristic of the stochastic multi-resonance
phenomenon. 相似文献
14.
Tao Yang Qinglin Han Chunhua Zeng Hua Wang Yunchang Fu Chun Zhang 《Central European Journal of Physics》2014,12(6):383-391
The phenomenon of stochastic resonance (SR) in a tumor growth model under the presence of immune surveillance is investigated. Time delay and cross-correlation between multiplicative and additive noises are considered in the system. The signal-to-noise ratio (SNR) is calculated when periodic signal is introduced multiplicatively. Our results show that: (i) the time delay can accelerate the transition from the state of stable tumor to that of extinction, however the correlation between two noises can accelerate the transition from the state of extinction to that of stable tumor; (ii) the time delay and correlation between two noises can lead to a transition between SR and double SR in the curve of SNR as a function of additive noise intensity, however for the curve of SNR as a function of multiplicative noise intensity, the time delay can cause the SR phenomenon to disappear, and the cross-correlation between two noises can lead to a transition from SR to stochastic reverse-resonance. Finally, we compare the SR phenomenon for the multiplicative periodic signal with that for additive periodic signal in the tumor growth model with immune surveillance. 相似文献
15.
We study the effect of time delay in the FitzHugh-Nagumo neural model with correlations between multiplicative and additive noise terms. Based on the corresponding Fokker-Planck equation, the explicit expressions of the stationary probability distribution function (SPDF), the mean first passage time (MFPT) and the signal-to-noise ratio (SNR) are obtained, respectively. Research results show that: (i) the system undergoes a succession of two phase transitions (i.e., the reentrance phenomenon) as the noise correlation parameter is increased and a (single) phase transition as the time delay is increased. (ii) The MFPT as a function of the multiplicative noise intensity exhibits a maximum. This maximum for MFPT identifies the noise enhanced stability (NES) effect, the noise correlation parameter intensifies the NES effect while the time delay, and the additive noise intensity weakens it. (iii) The existence of a maximum in the SNR as a function of the multiplicative noise intensity is the identifying characteristic of the stochastic resonance (SR) phenomenon, the noise correlation parameter enhances the SR while the time delay, and the additive noise intensity weaken it. 相似文献
16.
研究了乘性非高斯噪声和加性高斯白噪声共同激励下非对称双稳系统的平均首次穿越时间和随机共振问题. 利用路径积分法和两态模型理论,推导出平均首次穿越时间和信噪比的表达式. 研究结果表明:势阱非对称性对两个不同方向的平均首次穿越时间的影响是不同的. 信噪比是加性噪声强度和势阱非对称性的非单调函数,系统出现了随机共振现象;信噪比是乘性噪声强度的单调函数,没有共振峰出现. 这说明该系统中乘性噪声强度和加性噪声强度对信噪比的影响是不同的.
关键词:
非高斯噪声
非对称双稳系统
平均首次穿越时间
随机共振 相似文献
17.
The stochastic resonance (SR) behavior for an underdamped bistable system driven by square-wave signal and multiplicative noise is investigated. Under the adiabatic approximation condition, the expression for the system output signal-to-noise ratio (SNR) is obtained. The analysis results show that stochastic multi-resonance phenomenon occurs when the SNR varies with the intensities of the multiplicative and additive noise. SR phenomenon can be observed on the curves of the SNR versus the system bias, versus the amplitude of the dichotomous noise and versus the amplitude of the square-wave signal. Moreover, the SNR varies non-monotonously with the variety of other system parameters. 相似文献
18.
Effects of time delay on stochastic resonance of a periodically driven linear system with multiplicative and periodically modulated additive white noises
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Stochastic resonance (SR) of a periodically driven time-delayed
linear system with multiplicative white noise and periodically
modulated additive white noise is investigated. In the condition of
small delay time, an approximate analytical expression of output
signal-to-noise ratio (SNR) is obtained. The analytical results
indicate that (1) there exists a resonance peak in the curve for
SNR versus time delay; (2) the time delay will suspend the SR
dramatically for SNR versus other parameters of the system, such as
noise intensity, correlation intensity, and signal frequency, once a
certain value is reached, the SR phenomenon disappears. 相似文献
19.
We consider the problem of scattering of a guided TE-mode in a planar optical waveguide with small random irregularities. The results of numerical solution of the direct and inverse problems of waveguide scattering for a statistical stationary nanometer surface roughness are presented. We show the possibility of retrieving information on the statistical properties of the surface roughness from scattered-radiation measurements in the far region (or in the equivalent Fourier plane). It is found that superresolution can be reached in a roughness correlation range of about /30-/20 for high signal-to-noise ratios by optimizing the optical-transfer function and efficient smoothing. 相似文献
20.
Kang-Kang Wang Lin Ju Ya-Jun Wang Sheng-Hong Li 《Chinese Journal of Physics (Taipei)》2018,56(1):96-107
In this paper, we focus on investigating the steady-state shift behaviors and the stochastic resonance phenomenon (SR) for a biological insect population system with a multiplicative periodic signal caused by the terms of the colored multiplicative and additive noises. Our research results imply that the multiplicative noise and the self-correlation of the additive noise can weaken the stability of the biological system and restrain the growth of the insect population, while the additive noise and the self-correlation time of the multiplicative noise can strengthen the stability of the insect system and facilitate the biological population to breed. As regards to the phenomenon of the SR evoked by a multiplicative periodic signal, noise terms and their correlation times, the computed results show that the additive noise intensity M and the self- correlation time τ1 of the multiplicative noise can both improve the SR effect. Inversely, the multiplicative noise intensity Q and the self-correlation time τ2 of the additive noise can suppress together the SR phenomenon. Whereas, it should be pointed out that in the SNR-Q and SNR-M plots, the two self-correlation times can both motivate a resonant peak, but not change the peak value of the SNR no matter how the two noise correlation times vary. 相似文献