Re: DATA on collapsing WTC

[brian whatcott <inet@INTELLISYS.NET>]

At 10:03 9/22/01 -0700, John Mallinkrodt wrote:

> ...  In fact, what the residuals indicate is
> that the model gives y-values that are too low (i.e., more
> negative than the data) near t = 0, 2, and 5 seconds and too large
> (i.e., less negative than the data) near t = 1 and 4 seconds.
/snip/
> John Mallinckrodt

I optimized the residual with a 3 second periodic fundamental
frequency lagging by pi and a 1.5 second, second harmonic of one
quarter the amplitude at zero phase for a stratospheric match
 of the variance accounted for by the model of r^2 = 99.98%.

I see that this is in effect a fourier synthetic effort by
the regression to account for a distinct upgoing transient occurring
around 1.4 to 1.6 seconds into the record.
(The synthesis of the two waves provides a sawtooth with a sharp
rising 'edge'at this time opposing the smoothly
 modeled displacement.)

This is consistent with a temporary restraint of the fall by
the next floor beneath the subsidence.

Such a conclusion would be unwise however. The residual
does show a sinusoid of constant frequency and amplitude.
 These two features are both contra indicated for an
accelerated floor by floor effect.

Brian W

brian whatcott <inet@intellisys.net>  Altus OK
                Eureka!