ABSTRACT
The two time constants τ1 and τ2 determine the speed and shape of the oscillator output. For stable oscillation, τ1/τ2 should be in the range of 0.1∼0.5 (Williamson 1998).
3 NEURAL-OSCILLATOR BEHAVIOR
When no input is applied to the neural-oscillator, it oscillates at a natural frequency f , as shown in Figure 2. Natural frequency of the oscillator when β = 2.5, γ = 2.5, c = 1.5 is calculated under changing two time constants τ1 and τ2. Figure 3 shows the output frequency of the oscillator plotted against 1/τ1. It can be seen from this figure that the oscillator frequency is proportion to the magnitude of 1/τ1 under the condition that the ratio of τ1/τ2 is constant. Therefore, the natural frequency of the oscillator when β = 2.5, γ = 2.5, c = 1.5 (CASE-252515) can be evaluated by using the proposed equation as shown in Table 1. The evaluation equation for β = 1.5, γ = 1.5, c = 1.5 (CASE-151515) is also shown in Table 2 (Yoneda et al. 2008). Based on the results of comparison between Table 1 and Table 2, it is assumed that the natural frequency of the oscillator slightly depend on the values of β and γ .
