The White-Noise Method in System Identification
The White-Noise Method in System Identification
复制标题
系统辨识中的白噪声方法
DOI：
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发表时间：
1978
期刊：
影响因子：
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通讯作者：
V. Marmarelis
中科院分区：
文献类型：
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作者：
P. Z. Marmarelis;V. Marmarelis
在生理系统动力学研究的早期，生物科学家面临的任务是识别系统执行的刺激-反应转换的线性和非线性域，以及这些域如何与系统环境中刺激的主要自然变化进行比较。正如我们在前一章所看到的，线性系统的分析优点很多，因此，它们证明了在系统的操作范围内（如果存在的话）寻找线性域是合理的。然而，生物科学家必须抵制诱惑，不要被对美丽和明确解决方案的自然渴望所迷惑，因为它们往往是不切实际的理想化。我们不得不承认，非线性系统的特性在自然界中是丰富的，而且远远超出了每一个物理系统在某种程度上都是非线性的这一陈词滥调。就像非线性优化了人工系统的设计一样，从行为的角度来看，非线性似乎是生理系统最佳功能的必要条件。这样的例子很多：为了适应大的刺激范围而进行的感觉输入的对数变换、由诸如感觉方向等生理需要引起的动态不对称性以及许多其他。
Early in the study of the dynamics of a physiological system the bioscientist is faced with the task of recognizing the domains of linearity and of nonlinearity of the stimulus-response transformation that the system performs and how these domains compare with the dominant natural variation of the stimuli in the system’s environment. As we saw in the previous chapter, the analytical advantages of linear systems are many, and, therefore, they justify the search for a linear domain in the system’s operational range (if such exists). However, the bioscientist must resist the temptation of being carried away by a natural desire for beautiful and explicit solutions since they often tend to be unrealistic idealizations. We cannot but bow to the evidence that nonlinear system characteristics are abundant in nature and go far beyond the trite admission that every physical system is in some way nonlinear. In much the same way that nonlinearities optimize the design of artificial systems, nonlinearities seem to be necessary for the optimal functioning of physiological systems from the behavioral point of view. There are many such examples: the logarithmic transformation of sensory input in order to accommodate large stimulus ranges, dynamic asymmetries arising from such physiological necessities as sensing direction, and many others.