>> So when approaching a floor it would suddenly slam to a stop when it
reached the proper location
Heh I've spent one lunch break in that elevator. In the sub-sub basement...
forklift driver was bad with numbers...
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Reply by ●April 22, 20142014-04-22
On Sun, 20 Apr 2014 20:55:11 -0400, robert bristow-johnson
<rbj@audioimagination.com> wrote:
Reply by glen herrmannsfeldt●April 21, 20142014-04-21
kevinjmcee <kevinjmcgee@netscape.net> wrote:
> On CNN a few nights ago, some people were discussing the missing
> plane, when someone mentioned the equipment aboard one of the
> Australian Navy ships (something to the effect of "... don't they
> have magnetometers for hunting submarines?").
> I think it took a while before one of the other panelists came
> up with the comment that "submarines are made of steel, and
> airplanes are made of aluminum and carbon composite."
When the last plane sank in the ocean, and there was discussion on
how long the pings last, I was wondering why no exponential back-off
on the ping rate. That would make it harder and harder, but not
impossible, to find at later times.
To get an actual DSP question, I was wondering what was the best
way to process the signal from a bunch of microphones in the ocean
listening for pings. Seems to me that if you combine the signals
from many microphones with variable delay, it should be possible
to do better than with each one individually. But I don't know
the numbers for the actual pings or microphones.
-- glen
Reply by glen herrmannsfeldt●April 21, 20142014-04-21
Eric Jacobsen <eric.jacobsen@ieee.org> wrote:
(snip)
> Decades ago when Fuzzy Logic was a Big Deal there was an "expert" on
> the radio explaining how a normal digital control system running an
> elevator would only have two states, where the elevator was moving or
> stopped. So when approaching a floor it would suddenly slam to a
> stop when it reached the proper location. The far superior fuzzy
> logic system got around this by allowing the elevator to slow down
> gradually before it reached the proper location.
Interesting way to explain it.
If you consider it an analogy, it might not be so bad.
Like many analogies, you shouldn't take them too literally, but
that is likely what happens if you use that explanation with
non-scientists.
But elevator logic really does need work.
I know way too many elevator systems with more than one elevator,
and when you press the button all of them come. That is not, as
Spock would say, logical.
Now, how about a good explanation of neural-nets for non-scientists.
-- glen
Reply by kevinjmcee●April 21, 20142014-04-21
On CNN a few nights ago, some people were discussing the missing plane, when someone mentioned the equipment aboard one of the Australian Navy ships (something to the effect of "... don't they have magnetometers for hunting submarines?"). I think it took a while before one of the other panelists came up with the comment that "submarines are made of steel, and airplanes are made of aluminum and carbon composite." I don't think there was much discussion on the magnetic (or non-magnetic) properties of materials, nor the weak propagation of electromagnetic energy in the ocean.
On a different panel discussion some time previously, someone else had also mentioned the deep sound channel, which lead me to wondering what the heck it had to do with finding a pinger, given that the deep sound channel has a low frequency cut-off.
But occasionally, CNN will have someone on who has a background in oceanography or ocean acoustics. eg: people who actually read and know things like the following:
http://www.scor-int.org/IQOE/Cato_Paper.pdf
(interesting - the author writes about ambient noise off Perth, Australia).
Reply by Eric Jacobsen●April 20, 20142014-04-20
On Sun, 20 Apr 2014 16:15:56 -0700 (PDT), radams2000@gmail.com wrote:
>Step 1
>
>Buy adobe audition
>
>Step 2
>
>Mix white noise together with a beeping sound
>
>Step 3
>
>Run the built- in noise removal program
>
>Step 4.
>
>Appear multiple times on CNN to explain how, if the flight 370 beacon were still operating, they could pull it out if the noise. Or, if they ever find the black box, they could enhance the cockpit alerts.
>
>
>I want this job.
>
>Bob
Decades ago when Fuzzy Logic was a Big Deal there was an "expert" on
the radio explaining how a normal digital control system running an
elevator would only have two states, where the elevator was moving or
stopped. So when approaching a floor it would suddenly slam to a
stop when it reached the proper location. The far superior fuzzy
logic system got around this by allowing the elevator to slow down
gradually before it reached the proper location.
I've seen that sort of thing repeated dozens of times over the
decades. When the news/media outlets don't have a science/technology
editor (and most don't due to budgets), I think their search criteria
for an "expert" boils down to somebody willing to come on some sort of
marginal credential and within budget.
Eric Jacobsen
Anchor Hill Communications
http://www.anchorhill.com
Reply by robert bristow-johnson●April 20, 20142014-04-20
Step 1
Buy adobe audition
Step 2
Mix white noise together with a beeping sound
Step 3
Run the built- in noise removal program
Step 4.
Appear multiple times on CNN to explain how, if the flight 370 beacon were still operating, they could pull it out if the noise. Or, if they ever find the black box, they could enhance the cockpit alerts.
I want this job.
Bob