T.NO. 214 
2| 
kg/mm2/DEG2 T.NO. 214 
Hoppe 
10+1 
T.NO. 214 
9 on eR? 
Fig. 3.24. Example of three—inputs analysis; amplitude gain and phase shift. 
(From Yamanouchi.??) 
To show more clearly the usefulness of multi input analysis, apart from the nonlin- 
earity of responses, another example used the vertical acceleration as a linear output and 
rolling, pitching, and relative wave height as inputs. The multiple and partial coherencies 
are given in Fig. 3.27, in which the multiple coherency is almost 1 at the important range 
of frequencies and the contribution of rolling is large for this vertical acceleration, as we 
expected. 
Figure 3.28 is another example of two—input and three—input analysis for stress 
which does not take into account the nonlinearity of rolling. Comparison with Figs. 3.25 
and 3.26 at the important range of frequencies for stress shows lower coherencies when 
the nonlinear response of rolling is not taken into account. 
Later, the author found that taking the input process squared as an input is very rea- 
sonable in discussing the quadratic response character of the output as shown in Section 
11.4, in Part II. 
89 
