This paper investigates the stochastic resonance in a monostable system driven by square-wave signal, asymmetric dichotomous noise as well as by multiplicative and additive white noise. By the use of the properties of...This paper investigates the stochastic resonance in a monostable system driven by square-wave signal, asymmetric dichotomous noise as well as by multiplicative and additive white noise. By the use of the properties of the dichotomous noise, it obtains the expressions of the signal-to-noise ratio under the adiabatic approximation condition. It finds that the signal-to-noise ratio is a non-monotonic function of the asymmetry of the dichotomous noise, and which varies non- monotonously with the intensity of the multiplicative and additive noise as well as the system parameters. Moreover, the signal-to-noise ratio depends on the correlation rate and intensity of the dichotomous noise.展开更多
The entropic stochastic resonance (ESR) in a confined system subjected to dichotomous noise and white noise and driven by a periodic sinusoidal force along the x axis of the structure and a time-dependent force in t...The entropic stochastic resonance (ESR) in a confined system subjected to dichotomous noise and white noise and driven by a periodic sinusoidal force along the x axis of the structure and a time-dependent force in the declining direction, is investigated. Under the adiabatic approximation condition and based on the two-state theory, the expression of the output signal-to-noise ratio (SNR) is obtained. The results show that the SNR is a non-monotonic function of the strengths of dichotomous noise, white noise, and correlated strength of correlated noise. In addition, the SNR varies non-monotonically with the increase of the shape parameters of the confined structure, and also with the increase of the constant force along the y axis of the structure. The influence of the correlation rate of the dichotomous noise, and that of the frequency of the periodic force on the SNR are discussed.展开更多
In this paper, we investigate the solution moment stability for a Harrison-type predator-prey model with parametric dichotomous noises. Using the Shapiro-Loginov formula, the equations for the first-order and second-o...In this paper, we investigate the solution moment stability for a Harrison-type predator-prey model with parametric dichotomous noises. Using the Shapiro-Loginov formula, the equations for the first-order and second-order moments are obtained and the corresponding stable conditions are given. It is found that the solution moment stability depends on the noise intensity and correlation time of noise. The first-order and second-order moments become unstable with the decrease of correlation time. That is, the dichotomous noise can improve the solution moment stability with respect to Gaussian white noise. Finally, some numerical results are presented to verify the theoretical analyses.展开更多
A constant-potential system driven by multiplicative dichotomous noise and subject to an input oscillatory signal is investigated. Two phenomena of stochastic resonance are observed. One is the response as a function ...A constant-potential system driven by multiplicative dichotomous noise and subject to an input oscillatory signal is investigated. Two phenomena of stochastic resonance are observed. One is the response as a function of the noise's parameters; the other is that as a function of the input signal frequency. A phenomenon of multi-resonance (there are three or four peaks) is found for the response as a function of a parameter of the noise. A phenomenon of reverse-resonance is found, for which the response of the system to the signal can be weakened by the presence of the noise (there is an optimal minimum). These results help in studies of the systems with multiplicative dichotomous noise, such as the semiconductor, the proteins motor, the chemical reaction, and so on.展开更多
The effect of the correlation of two dichotomous noises on stochastic resonance is investigated for a linear stochastic system subject to a periodic oscillatory signal. It is found that, the correlation between the tw...The effect of the correlation of two dichotomous noises on stochastic resonance is investigated for a linear stochastic system subject to a periodic oscillatory signal. It is found that, the correlation between the two dichotomous noises can not only affect the appearance of the stochastic resonance phenomenon, but also the distinctness of the stochastic resonance phenomenon. There is an optimal value of the correlation, at which the stochastic resonance phenomenon is most distinct. In addition, the correlation between the two dichotomous noises can also cause the movement of the peak of stochastic resonance. Finally, two stochastic resonances caused by two correlated multiplicative dichotomous noises can be found in this system.展开更多
The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated...The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated algorithm.The deregularization maximized the energy of the solution,which was opposite to the Tikhonov regularization where the energy was minimized.However,combined with box-constraints,the deregularization forced the solution to be close to the binary set.It further exploited the box-constrained dichotomous coordinate descent algorithm and adapted it to the nonstationary iterative Tikhonov regularization to present an efficient detector.As a result,the worst-case and average complexity are reduced down as K2.8 and K2.5 floating point operation per second,respectively.The development improves the "efficient frontier" in multiuser detection,which is illustrated by simulation results.In addition,most operations in the detector are additions and bit-shifts.This makes the proposed technique attractive for fixed-point hardware implementation.展开更多
The stochastic resonance phenomenon in a harmonic oscillator with fluctuating intrinsic frequency by asymmetric dichotomous noise is investigated in this paper. By using the random average method and Shapiro- Loginov ...The stochastic resonance phenomenon in a harmonic oscillator with fluctuating intrinsic frequency by asymmetric dichotomous noise is investigated in this paper. By using the random average method and Shapiro- Loginov formula, the exact solution of the average output amplitude gain (OAG) is obtained. Numerical results show that OAG depends non-monotonically on the noise characteristics: intensity, correlation time and asymmetry. The maximum OAG can be achieved by tuning the noise asymmetry and or the noise correlation time.展开更多
In this paper, we introduce a noise which is composed of multiplication of two dichotomous noises, and derive the probability density and the statistical properties of this noise. The obtained results can help study t...In this paper, we introduce a noise which is composed of multiplication of two dichotomous noises, and derive the probability density and the statistical properties of this noise. The obtained results can help study the resonant activation phenomenon, the phenomenon of stochastic resonance, the transport of particles, and the nonequilibrium (phase) transition for the systems driven by this noise.展开更多
A stochastic system driven by dichotomous noise and periodic signal is investigated in the under-damped case.The exact expressions of output signal amplitude and signal-to-noise ratio(SNR) of the system are derived....A stochastic system driven by dichotomous noise and periodic signal is investigated in the under-damped case.The exact expressions of output signal amplitude and signal-to-noise ratio(SNR) of the system are derived.Numerical results indicate that the inertial mass greatly affects the output signal amplitude and the SNR.Regardless of whether the noise is symmetric or asymmetric,the inertial mass can influence the phenomenon of stochastic resonance(SR) of the system,leading to two types of resonance phenomenon:one is coherence-resonance-like of the SNR with inertial mass,the other is the SR of the SNR with noise intensity.展开更多
This paper studies the mean first passage time (or exit time, or escape time) over the non-fluctuating potential harrier for a system driven only by a dichotomous noise. It finds that the dichotomous noise can make ...This paper studies the mean first passage time (or exit time, or escape time) over the non-fluctuating potential harrier for a system driven only by a dichotomous noise. It finds that the dichotomous noise can make the particles escape over the potential barrier, in some circumstances; but in other circumstances, it can not. In the case that the particles escape over the potential harrier, a resonant activation phenomenon for the mean first passage time over the potential barrier is obtained.展开更多
A data-aided technique for cartier frequency offset estimation with continuous phase modulation (CPM) in burst- mode transmission is presented. The proposed technique first exploits a special pilot sequence, or trai...A data-aided technique for cartier frequency offset estimation with continuous phase modulation (CPM) in burst- mode transmission is presented. The proposed technique first exploits a special pilot sequence, or training sequence, to form a sinusoidal waveform. Then, an improved dichotomous search frequency offset estimator is introduced to determine the frequency offset using the sinusoid. Theoretical analysis and simulation results indicate that our estimator is noteworthy in the following aspects. First, the estimator can operate independently of timing recovery. Second, it has relatively low outlier, i.e., the minimum signal-to-noise ratio (SNR) required to guarantee estimation accuracy. Finally, the most important property is that our estimator is complexity-reduced compared to the existing dichotomous search methods: it eliminates the need for fast Fourier transform (FFT) and modulation removal, and exhibits faster convergence rate without accuracy degradation.展开更多
A linear system driven by dichotomous noise and a periodic signal is investigated in the underdamped case. The exact expressions of output signal amplitude and signal-to-noise ratio (SNR) of the system are derived. ...A linear system driven by dichotomous noise and a periodic signal is investigated in the underdamped case. The exact expressions of output signal amplitude and signal-to-noise ratio (SNR) of the system are derived. By means of numerical calculation, the results indicate that (i) at some fixed noise intensities, the output signal amplitude with inertial mass exhibits the structure of a single peak and single valley, or even two peaks if the dichotomous noise is asymmetric; (ii) in the case of asymmetric dichotomous noise, the inertial mass can cause non-monotonic behaviour of the output signal amplitude with respect to noise intensity; (iii) the curve of SNR versus inertial mass displays a maximum in the case of asymmetric dichotomous noise, i.e., a resonance-like phenomenon, while it decreases monotonically in the case of symmetric dichotomous noise; (iv) if the noise is symmetric, the inertial mass can induce stochastic resonance in the system.展开更多
This study used double-bounded dichotomous-choice to estimate and analyze the factors affecting households’ willingness to pay (WTP) for water quality improvement. This study notes that households with higher income,...This study used double-bounded dichotomous-choice to estimate and analyze the factors affecting households’ willingness to pay (WTP) for water quality improvement. This study notes that households with higher income, living near a polluted water source, using tap water instead of natural water, who are handicraft producers, and who have more members, are willing to pay more. However, households who rarely hear about environmental pollution issues and who are offered a higher bid are more likely to refuse to pay. Solutions to improve water quality are suggested such as to raise people’s awareness through communication channels and social organizations;to increase income associated with environmental protection policies;to construct wastewater treatment plants;to encourage the relocation of production establishments to industrial parks and industrial complexes;to put regulations on collection, payment and sanctions in case of not declaring and paying fees into village conventions;to promulgate circulars, and bylaws to concretize and simplify regulations and policies of the Government and the Ministry of Natural Resources and Environment.展开更多
This study explored cross-cultural differences between Japan and Russia in terms of women’s body images, proneness to eating disorders, and the effects of dichotomous thinking. Participants included 419 Japanese and ...This study explored cross-cultural differences between Japan and Russia in terms of women’s body images, proneness to eating disorders, and the effects of dichotomous thinking. Participants included 419 Japanese and 187 Russian college women who completed the Dichotomous Thinking Inventory (DTI), the 26-item version of the Eating Attitudes Test, and responses regarding nine figures representing female body shapes. The mean age of the participants was 19.8 years, with no significant age differences between the countries. The results showed that Japanese women have leaner ideal body images than Russian women, whereas there were no cross-cultural differences in the participants’ real body images. DTI scores among Russian participants were higher than DTI scores among Japanese participants, which indicated that Russian women think more dichotomously than Japanese. Structural equation modeling indicated a significantly negative effect of dichotomous thinking only on real body image in Russia;the ideal body image had greater effects on eating disorder in Russia than in Japan.展开更多
The transport of particles induced by multiplicative dichotomous noise for a system is investigated. The stationary probability current is derived. It is shown that, for the system studied by us, the spatial asymmetry...The transport of particles induced by multiplicative dichotomous noise for a system is investigated. The stationary probability current is derived. It is shown that, for the system studied by us, the spatial asymmetry is the ingredient for the nonzero stationary current.展开更多
We investigate statistical properties of multispecies competition ecosystems subjected to both symmetric and asymmetric dichotomous noises. The expression of the stationary probability distribution function (SPDF) i...We investigate statistical properties of multispecies competition ecosystems subjected to both symmetric and asymmetric dichotomous noises. The expression of the stationary probability distribution function (SPDF) is analytically derived by means of mean-field approximation, and verified by stochastic simulations. The results indicate that: (i) A noise amplitude (a0), a noise autocorrelation time (τ0) and a noise symmetry parameter (k) all can affect the SPDF; (ii) There is an optimal τ0, which makes the mean value of population density be maximal, near which a transition takes place, i.e., the stationary mean value of species density ((x)st) suddenly falls to a lower constant, (iii) As k decreases, the maximum of (x)xt and the optimal 70 increase. The parameter planes of TO -- a20 and τ0- k for the transition are plotted.展开更多
In this paper, an additive dichotomous noise model and a multiplicative dichotomous noise model are investigated for the effect of the asymmetry of the additive and multiplicative dichotomous noises on the transport o...In this paper, an additive dichotomous noise model and a multiplicative dichotomous noise model are investigated for the effect of the asymmetry of the additive and multiplicative dichotomous noises on the transport of the particles, in the presence of spatial symmetry and asymmetry, respectively. It is shown that, in the presence of spatial asymmetry, the asymmetry of the dichotomous noise can weaken or enhance the transport of the particles; while in the absence of spatial asymmetry, the nonzero current induced by the noise's asymmetry is "symmetric" around the zero current. In addition, a current reversal can be produced by controlling the noise's asymmetry parameter; and we find that, for some values of the noise's asymmetry parameter, the multiplicative dichotomous noise can more easily induce the transport of the particles than the additive dichotomous noise.展开更多
The collective behaviors of two coupled harmonic oscillators with dichotomous fluctuating frequency are investigated,including stability, synchronization, and stochastic resonance(SR). First, the synchronization condi...The collective behaviors of two coupled harmonic oscillators with dichotomous fluctuating frequency are investigated,including stability, synchronization, and stochastic resonance(SR). First, the synchronization condition of the system is obtained. When this condition is satisfied, the mean-field behavior is consistent with any single particle behavior in the system. On this basis, the stability condition and the exact steady-state solution of the system are derived. Comparative analysis shows that, the stability condition is stronger than the synchronization condition, that is to say, when the stability condition is satisfied, the system is both synchronous and stable. Simulation analysis indicates that increasing the coupling strength will reduce the synchronization time. In weak coupling region, there is an optimal coupling strength that maximizes the output amplitude gain(OAG), thus the coupling-induced SR behavior occurs. In strong coupling region, the two particles are bounded as a whole, so that the coupling effect gradually disappears.展开更多
Abstract An electric circuit with dichotomous resistor is investigated. It is shown that the amplitude of the average electric current washing the resistor represents the phenomenon of stochastic resonance, which is t...Abstract An electric circuit with dichotomous resistor is investigated. It is shown that the amplitude of the average electric current washing the resistor represents the phenomenon of stochastic resonance, which is the response as a function of the correlation time of the dichotomous resistor.展开更多
基金Project supported by the Doctorial Foundation of Southwest University of Science and Technology of China(Grant No.08zx7108)
文摘This paper investigates the stochastic resonance in a monostable system driven by square-wave signal, asymmetric dichotomous noise as well as by multiplicative and additive white noise. By the use of the properties of the dichotomous noise, it obtains the expressions of the signal-to-noise ratio under the adiabatic approximation condition. It finds that the signal-to-noise ratio is a non-monotonic function of the asymmetry of the dichotomous noise, and which varies non- monotonously with the intensity of the multiplicative and additive noise as well as the system parameters. Moreover, the signal-to-noise ratio depends on the correlation rate and intensity of the dichotomous noise.
基金Project supported by the Open Fund of Key Laboratory of Education-Ministry Collaboration-Built (Southwest University of Science and Technology)-Manufacturing Process Test Technology,China (Grant No. 11zxzk08)
文摘The entropic stochastic resonance (ESR) in a confined system subjected to dichotomous noise and white noise and driven by a periodic sinusoidal force along the x axis of the structure and a time-dependent force in the declining direction, is investigated. Under the adiabatic approximation condition and based on the two-state theory, the expression of the output signal-to-noise ratio (SNR) is obtained. The results show that the SNR is a non-monotonic function of the strengths of dichotomous noise, white noise, and correlated strength of correlated noise. In addition, the SNR varies non-monotonically with the increase of the shape parameters of the confined structure, and also with the increase of the constant force along the y axis of the structure. The influence of the correlation rate of the dichotomous noise, and that of the frequency of the periodic force on the SNR are discussed.
基金Project supported by the National Natural Science Foundation of China(Grant No.11272051)
文摘In this paper, we investigate the solution moment stability for a Harrison-type predator-prey model with parametric dichotomous noises. Using the Shapiro-Loginov formula, the equations for the first-order and second-order moments are obtained and the corresponding stable conditions are given. It is found that the solution moment stability depends on the noise intensity and correlation time of noise. The first-order and second-order moments become unstable with the decrease of correlation time. That is, the dichotomous noise can improve the solution moment stability with respect to Gaussian white noise. Finally, some numerical results are presented to verify the theoretical analyses.
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
文摘A constant-potential system driven by multiplicative dichotomous noise and subject to an input oscillatory signal is investigated. Two phenomena of stochastic resonance are observed. One is the response as a function of the noise's parameters; the other is that as a function of the input signal frequency. A phenomenon of multi-resonance (there are three or four peaks) is found for the response as a function of a parameter of the noise. A phenomenon of reverse-resonance is found, for which the response of the system to the signal can be weakened by the presence of the noise (there is an optimal minimum). These results help in studies of the systems with multiplicative dichotomous noise, such as the semiconductor, the proteins motor, the chemical reaction, and so on.
基金Supported by Natural Science Foundation of China under Grant No. 10975079the Natural Science Foundation of Ningbo under Grant No. 2008A61003 K.C. Wong Magna Fund in Ningbo University of China
文摘The effect of the correlation of two dichotomous noises on stochastic resonance is investigated for a linear stochastic system subject to a periodic oscillatory signal. It is found that, the correlation between the two dichotomous noises can not only affect the appearance of the stochastic resonance phenomenon, but also the distinctness of the stochastic resonance phenomenon. There is an optimal value of the correlation, at which the stochastic resonance phenomenon is most distinct. In addition, the correlation between the two dichotomous noises can also cause the movement of the peak of stochastic resonance. Finally, two stochastic resonances caused by two correlated multiplicative dichotomous noises can be found in this system.
文摘The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated algorithm.The deregularization maximized the energy of the solution,which was opposite to the Tikhonov regularization where the energy was minimized.However,combined with box-constraints,the deregularization forced the solution to be close to the binary set.It further exploited the box-constrained dichotomous coordinate descent algorithm and adapted it to the nonstationary iterative Tikhonov regularization to present an efficient detector.As a result,the worst-case and average complexity are reduced down as K2.8 and K2.5 floating point operation per second,respectively.The development improves the "efficient frontier" in multiuser detection,which is illustrated by simulation results.In addition,most operations in the detector are additions and bit-shifts.This makes the proposed technique attractive for fixed-point hardware implementation.
文摘The stochastic resonance phenomenon in a harmonic oscillator with fluctuating intrinsic frequency by asymmetric dichotomous noise is investigated in this paper. By using the random average method and Shapiro- Loginov formula, the exact solution of the average output amplitude gain (OAG) is obtained. Numerical results show that OAG depends non-monotonically on the noise characteristics: intensity, correlation time and asymmetry. The maximum OAG can be achieved by tuning the noise asymmetry and or the noise correlation time.
基金Project supported by the Ningbo's supplement of the National Natural Science Foundation of China (Grant No 10375009)the Scientific Research Starting Foundation for the Returned Overseas Chinese Scholars Ministry of Education, Chinathe K. C. Wang Magna Fund in Ningbo University, China
文摘In this paper, we introduce a noise which is composed of multiplication of two dichotomous noises, and derive the probability density and the statistical properties of this noise. The obtained results can help study the resonant activation phenomenon, the phenomenon of stochastic resonance, the transport of particles, and the nonequilibrium (phase) transition for the systems driven by this noise.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10847139)the Yunnan Provincial Foundation,China (Grant Nos. 2009CD036 and 08Z0015)
文摘A stochastic system driven by dichotomous noise and periodic signal is investigated in the under-damped case.The exact expressions of output signal amplitude and signal-to-noise ratio(SNR) of the system are derived.Numerical results indicate that the inertial mass greatly affects the output signal amplitude and the SNR.Regardless of whether the noise is symmetric or asymmetric,the inertial mass can influence the phenomenon of stochastic resonance(SR) of the system,leading to two types of resonance phenomenon:one is coherence-resonance-like of the SNR with inertial mass,the other is the SR of the SNR with noise intensity.
基金supported by the Scientific Research Foundation (SRF) for the Returned Overseas Chinese Scholars (ROCS), State Education Ministry (SEM), and by K. C. Wong Magna Fund in Ningbo University
文摘This paper studies the mean first passage time (or exit time, or escape time) over the non-fluctuating potential harrier for a system driven only by a dichotomous noise. It finds that the dichotomous noise can make the particles escape over the potential barrier, in some circumstances; but in other circumstances, it can not. In the case that the particles escape over the potential harrier, a resonant activation phenomenon for the mean first passage time over the potential barrier is obtained.
基金supported by the National Natural Science Foundation of China(Grant No.61301179)the Doctorial Programs Foundation of the Ministry of Education,China(Grant No.20110203110011)the Programme of Introducing Talents of Discipline to Universities,China(Grant No.B08038)
文摘A data-aided technique for cartier frequency offset estimation with continuous phase modulation (CPM) in burst- mode transmission is presented. The proposed technique first exploits a special pilot sequence, or training sequence, to form a sinusoidal waveform. Then, an improved dichotomous search frequency offset estimator is introduced to determine the frequency offset using the sinusoid. Theoretical analysis and simulation results indicate that our estimator is noteworthy in the following aspects. First, the estimator can operate independently of timing recovery. Second, it has relatively low outlier, i.e., the minimum signal-to-noise ratio (SNR) required to guarantee estimation accuracy. Finally, the most important property is that our estimator is complexity-reduced compared to the existing dichotomous search methods: it eliminates the need for fast Fourier transform (FFT) and modulation removal, and exhibits faster convergence rate without accuracy degradation.
基金supported by the National Natural Science Foundations of China (Grant No. 10847139)the Science Foundation of Yunnan Province of China (Grant Nos. 2009CD036 and 08Z0015)
文摘A linear system driven by dichotomous noise and a periodic signal is investigated in the underdamped case. The exact expressions of output signal amplitude and signal-to-noise ratio (SNR) of the system are derived. By means of numerical calculation, the results indicate that (i) at some fixed noise intensities, the output signal amplitude with inertial mass exhibits the structure of a single peak and single valley, or even two peaks if the dichotomous noise is asymmetric; (ii) in the case of asymmetric dichotomous noise, the inertial mass can cause non-monotonic behaviour of the output signal amplitude with respect to noise intensity; (iii) the curve of SNR versus inertial mass displays a maximum in the case of asymmetric dichotomous noise, i.e., a resonance-like phenomenon, while it decreases monotonically in the case of symmetric dichotomous noise; (iv) if the noise is symmetric, the inertial mass can induce stochastic resonance in the system.
文摘This study used double-bounded dichotomous-choice to estimate and analyze the factors affecting households’ willingness to pay (WTP) for water quality improvement. This study notes that households with higher income, living near a polluted water source, using tap water instead of natural water, who are handicraft producers, and who have more members, are willing to pay more. However, households who rarely hear about environmental pollution issues and who are offered a higher bid are more likely to refuse to pay. Solutions to improve water quality are suggested such as to raise people’s awareness through communication channels and social organizations;to increase income associated with environmental protection policies;to construct wastewater treatment plants;to encourage the relocation of production establishments to industrial parks and industrial complexes;to put regulations on collection, payment and sanctions in case of not declaring and paying fees into village conventions;to promulgate circulars, and bylaws to concretize and simplify regulations and policies of the Government and the Ministry of Natural Resources and Environment.
文摘This study explored cross-cultural differences between Japan and Russia in terms of women’s body images, proneness to eating disorders, and the effects of dichotomous thinking. Participants included 419 Japanese and 187 Russian college women who completed the Dichotomous Thinking Inventory (DTI), the 26-item version of the Eating Attitudes Test, and responses regarding nine figures representing female body shapes. The mean age of the participants was 19.8 years, with no significant age differences between the countries. The results showed that Japanese women have leaner ideal body images than Russian women, whereas there were no cross-cultural differences in the participants’ real body images. DTI scores among Russian participants were higher than DTI scores among Japanese participants, which indicated that Russian women think more dichotomously than Japanese. Structural equation modeling indicated a significantly negative effect of dichotomous thinking only on real body image in Russia;the ideal body image had greater effects on eating disorder in Russia than in Japan.
基金The project supported by SRF for ROCS,SEM,and by K.C.Wong Magna Fund in Ningbo University
文摘The transport of particles induced by multiplicative dichotomous noise for a system is investigated. The stationary probability current is derived. It is shown that, for the system studied by us, the spatial asymmetry is the ingredient for the nonzero stationary current.
基金Supported by the Yunnan Provincial Foundation of China under Grant Nos.2009CD036 and 08Z0015the National Natural Science Foundations of China under Grant Nos.50734009 and 10865006
文摘We investigate statistical properties of multispecies competition ecosystems subjected to both symmetric and asymmetric dichotomous noises. The expression of the stationary probability distribution function (SPDF) is analytically derived by means of mean-field approximation, and verified by stochastic simulations. The results indicate that: (i) A noise amplitude (a0), a noise autocorrelation time (τ0) and a noise symmetry parameter (k) all can affect the SPDF; (ii) There is an optimal τ0, which makes the mean value of population density be maximal, near which a transition takes place, i.e., the stationary mean value of species density ((x)st) suddenly falls to a lower constant, (iii) As k decreases, the maximum of (x)xt and the optimal 70 increase. The parameter planes of TO -- a20 and τ0- k for the transition are plotted.
基金Supported by National Natural Science Foundation of China under Grant No. 10975079the Natural Science Foundation of Ningbo under Grant No. 2008A61003K.C. Wong Magna Fund in Ningbo University of China
文摘In this paper, an additive dichotomous noise model and a multiplicative dichotomous noise model are investigated for the effect of the asymmetry of the additive and multiplicative dichotomous noises on the transport of the particles, in the presence of spatial symmetry and asymmetry, respectively. It is shown that, in the presence of spatial asymmetry, the asymmetry of the dichotomous noise can weaken or enhance the transport of the particles; while in the absence of spatial asymmetry, the nonzero current induced by the noise's asymmetry is "symmetric" around the zero current. In addition, a current reversal can be produced by controlling the noise's asymmetry parameter; and we find that, for some values of the noise's asymmetry parameter, the multiplicative dichotomous noise can more easily induce the transport of the particles than the additive dichotomous noise.
基金supported by the National Natural Science Foundation of China for the Youth (Grant Nos. 11501385 and 11801385)。
文摘The collective behaviors of two coupled harmonic oscillators with dichotomous fluctuating frequency are investigated,including stability, synchronization, and stochastic resonance(SR). First, the synchronization condition of the system is obtained. When this condition is satisfied, the mean-field behavior is consistent with any single particle behavior in the system. On this basis, the stability condition and the exact steady-state solution of the system are derived. Comparative analysis shows that, the stability condition is stronger than the synchronization condition, that is to say, when the stability condition is satisfied, the system is both synchronous and stable. Simulation analysis indicates that increasing the coupling strength will reduce the synchronization time. In weak coupling region, there is an optimal coupling strength that maximizes the output amplitude gain(OAG), thus the coupling-induced SR behavior occurs. In strong coupling region, the two particles are bounded as a whole, so that the coupling effect gradually disappears.
基金The project supported by National Natural Science Foundation of China under Grant No, 10375009, and the Scientific Research Foundation for Research 0verseas Chinese Scholars of the State Education Ministry of China. and by K.C. Wong Magna Fund in Ningbo University
文摘Abstract An electric circuit with dichotomous resistor is investigated. It is shown that the amplitude of the average electric current washing the resistor represents the phenomenon of stochastic resonance, which is the response as a function of the correlation time of the dichotomous resistor.