Modes of Neuristor Propagation, a Study in Distributed Active Processes

摘要

A neuristor line is a special form of physical system in corporating distributed active processes. Previous reports have shown how digital logic systems can be synthesized with networks of such lines. This report is not concerned with the logical aspects of neuristor networks but instead attempts to connect a variety of observations on neuristor and neural structure into one framework based largely on a simplified model representation of a neuristor device. This model, consisting of a linear R-C transmission line with distributed shunt negative conductance processes, was selected because it is sufficiently simple to permit formal mathematical analysis and yet adequately complex to display many of the more interesting features of neuristor behavior. We begin with a discussion of negative conductance elements of the type one might employ in the modeling of a neuristor line. Questions relating to realizability, switching speed, and stability of individual elements and their distributed versions are discussed. Some common misconceptions concerning switching in negative conductance devices are pointed out in a detailed physical description of the switching process. We then proceed to mathematical descriptions of diffusion type (R-C) lines employing shunt active processes. A computer simulation procedure is presented in which we develop some criteria to be observed in obtaining accurate solutions when lumped-line representations are used to approximate smoothly distributed line parameters. These rules give convenient estimates of the time and distance increments one must employ to achieve a given degree of precision in the computer solution.