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中国物理学会期刊

噪声对集合种群稳定性的影响

CSTR: 32037.14.aps.61.120506

Effect of noises on the stability of a metapopulation

CSTR: 32037.14.aps.61.120506
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  • 本文在Levins模型的基础上研究了噪声对集合种群的稳定性的影响. 应用Fokker-Planck方程得到了系统的稳态概率分布函数和平均灭绝时间. 经过数值分析,结果如下: 无关联(=0 为加性噪声和乘性噪声之间的关联强度)时, 加性噪声强度和乘性噪声强度D均弱化集合种群的稳定性; 噪声之间关联(0)时, 随着的增大,系统的稳定性被增强. 当-(c-e-D)2/(4cD)1时, 诱导共振抑制现象. D存在一个临界值, 小于临界值时, D可以增强系统的稳定性.

     

    The Levins model subjected to the noise is employed to study the stability of a metapopulation. The analytic expressions of the stationary probability distribution function and the mean extinction time of the metapopulation are obtained according to the Fokker-Planck Equation. The results show that for the case of no correlation between the additive noise and the multiplicative noise (=0, is the intensity of correlation between multiplicative and additive noise), the increase of the additive noise intensity weakens the stability of a metapopulation; for the case of 0, enhances the stability of a metapopulation. For -(c-e-D)2/(4cD)1, can induce the resonance restrain phenomenon. Meantime, there exists a critical value of D. When D is lower than the critical value, the stability of the system is enhanced.

     

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