Question in Detection

John E. Hadstate wrote:

(snip)
>>>[snip incredibly offensive, possibly drunken, rant
>>>attributed to Randy Yates]

> I have monitored this group for a long time--not as long as 
> you have--but a long time.  I don't think I have ever seen a 
> similar post by Randy Yates.  For that reason, I urge you to 
> consider the possibility this post was a "Joe Job" by some 
> fruitcake with whom Randy has had a disagreement.  
(snip)

All Randy Yates post this year are from the same IP address.

Ones from last year had a different address.

It is not impossible to forge IP addresses, the easiest being
to hack into someones computer, but it doesn't seem likely.

I have to say, though, I have been reasonably satisfied with
Randy's posts over the years.   I have been in some disagreements
with him, but usually friendly enough.

-- glen

"glen herrmannsfeldt" <gah@ugcs.caltech.edu> wrote in 
message news:gPadnc0Ir-805VjZnZ2dnUVZ_oqdnZ2d@comcast.com...
>
> All Randy Yates post this year are from the same IP 
> address.
>
> Ones from last year had a different address.
>
> It is not impossible to forge IP addresses, the easiest 
> being
> to hack into someones computer, but it doesn't seem 
> likely.
>

Depending on the network you plug into, it may be as simple 
as setting your TCP/IP stack to have a static IP address 
that matches the one you're trying to spoof.  If that other 
system is not active at the time you boot up, you may have 
no trouble appearing to be someone else.  (This option is 
generally not available to those who connect to the Internet 
through NATs or dial-up lines.)

> I have to say, though, I have been reasonably satisfied 
> with
> Randy's posts over the years.   I have been in some 
> disagreements
> with him, but usually friendly enough.

I have no dog in this fight, but if it's not a "Joe Job", 
I'd be willing to chalk it up to someone having had a 
seriously bad day.

Randy Yates wrote:
> Tim Wescott wrote:
>> [...]
> 
> Tim,
> 
> I simply asked that you be respectful. If that causes you this much
> grief, then there must be something deeply wrong in your own heart. I
> encourage you to examine it.

Randy, my friend, I think you mistake your own culturally inculcated 
trappings of respect for real respect. They aren't necessarily the same 
thing. I encourage you to consider widening your horizons.

Tim: I'm aware that Randy's statement could justly considered out of 
bounds, but I think your reaction to it was pretty strong. Certain his 
words themselves were not chosen to give offense. Will you reconsider?

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

John E. Hadstate wrote:

> "glen herrmannsfeldt" <gah@ugcs.caltech.edu> wrote in 

(snip)
>>It is not impossible to forge IP addresses, the easiest 
>>being to hack into someones computer, but it doesn't seem 
>>likely.

> Depending on the network you plug into, it may be as simple 
> as setting your TCP/IP stack to have a static IP address 
> that matches the one you're trying to spoof.  If that other 
> system is not active at the time you boot up, you may have 
> no trouble appearing to be someone else.  (This option is 
> generally not available to those who connect to the Internet 
> through NATs or dial-up lines.)

For UDP it is about that easy, but not for TCP.

For TCP you need to be able to predict the sequence numbering
for the packets.  (You don't get any ACKs back, as they go to the
real host with the address.)   Specifically to avoid this problem,
most now have ways to make it harder to predict the starting sequence
number.

-- glen

John E. Hadstate wrote:
> "Tim Wescott" <tim@seemywebsite.com> wrote in message
> news:9cednf0kr6-NvVjZnZ2dnUVZ_sOdnZ2d@web-ster.com...
> > Randy Yates wrote:
>
> >> [snip incredibly offensive, possibly drunken, rant
> >> attributed to Randy Yates]
>
> Tim,
>
> I have monitored this group for a long time--not as long as
> you have--but a long time.  I don't think I have ever seen a
> similar post by Randy Yates.  For that reason, I urge you to
> consider the possibility this post was a "Joe Job" by some
> fruitcake with whom Randy has had a disagreement.  Granted,
> such festivities are much more common in the Badlands of
> sci.crypt than they are here, but USENET is full of creeps
> and their numbers seem to be exploding.  Merely disagreeing
> with one of these brain-damaged cretins, no matter how
> mildly, is sufficient to trigger their wrath. None of the
> newsgroups in which I am a participant permits PKI-certified
> signed messages, so it's difficult to tell when some coward
> posts a message and attributes it to someone else.
>
> If, on the other hand, the post was genuine, I think your
> response was entirely reasonable.
>
> Just my two cents.
>
> --
>
> jeh

John et. al,

Where is reason here? Do you really think asking for a personal
greeting, especially in this context (i.e., between two old-timers)
is so completely out of line? I wonder why.

Regarding Jerry's comments about widening horizons, I don't
believe this is a matter of cultural insensitivity. I believe there
are certain absolute standards of respect that go across all
cultures and all times.

Regarding the authenticity question, yes, it really is me. How
do you know? I guess you don't. But you can call me and
talk to me in person. My phone number is 408-465-7076
(PST) until Thursday, then I'm back home in NC. That
is also why my IP addresses have changed - while I've
been away from home (since April 16th), I've been
posting through Google news rather than Earthlink's
usenet news server.

Tim, if you really feel the same way, you need to
replonk me.

--Randy

Randy Yates wrote:

   ...

> Tim, if you really feel the same way, you need to
> replonk me.

Randy,

To me, it wasn't simply the imparting of the information about how you 
want to be addressed, but that the way you put it seemed imperious. I 
don't mind your saying what you want -- I'll try to accommodate you when 
I remember -- but while you can always tell someone how you want to be 
treated, it's out of bounds to prescribe how another will behave.

I do think its a cultural matter. If we spoke face to face, you surely 
wouldn't expect me to begin each turn with "Randy comma". Many of the 
interchanges here are like an ongoing conversation. Those who see it 
that way -- I'm one -- jump right in with the meat of the matter. In any 
case, what you asked for -- it seemed to be a demand -- isn't respect, 
but the cultural trappings of respect in certain settings.

Congratulations on finally going home.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

glen herrmannsfeldt wrote:
> John E. Hadstate wrote:
>
> (snip)
> >>>[snip incredibly offensive, possibly drunken, rant
> >>>attributed to Randy Yates]
>
> > I have monitored this group for a long time--not as long as
> > you have--but a long time.  I don't think I have ever seen a
> > similar post by Randy Yates.  For that reason, I urge you to
> > consider the possibility this post was a "Joe Job" by some
> > fruitcake with whom Randy has had a disagreement.
> (snip)
>
> All Randy Yates post this year are from the same IP address.
>
> Ones from last year had a different address.
>
> It is not impossible to forge IP addresses, the easiest being
> to hack into someones computer, but it doesn't seem likely.
>
> I have to say, though, I have been reasonably satisfied with
> Randy's posts over the years.   I have been in some disagreements
> with him, but usually friendly enough.

Thanks for that, Glenn. It has been a pleasure to "spar" with
you over the years as well. "Wisdom is found in a multitude
of counselors."

My hope is that no one on this list misconstrues a technical
disagreement with personal enmity. The two are totally
separate issues, the current situation notwithstanding. 

--Randy

Hi Jerry,

I appreciate your efforts to bring understanding and peace to the
situation. I don't think peace is forthcoming, but I do sincerely
appreciate your efforts. Thank you.

--Randy

John E. Hadstate wrote:
> "Randy Yates" <yates@ieee.org> wrote in message
> news:1153764087.448643.174360@s13g2000cwa.googlegroups.com...
> > Hi,
> >
> > Suppose we have a signal y(t) that is composed
> > of white noise of unknown variance n(t) and potentially
> > a sinusoid of known power s(t) and known frequency
> > F, so that
> >
> >  y(t) = s(t) + n(t).
> >
> > The object is to detect the presence (or not) of
> > s(t).
> >
> > Is it better to simply filter the signal y(t) as
> > narrowly as possible and then set a detection
> > threshold, or would it be better to compare
> > the power in some off-band bandwidth
> > of y(t) to the power about F and make
> > a determination?
> >
>
> I would say that it is better to estimate the ratio of the
> signal power to the noise power.  I have recently created an
> "auto-squelch" function that does just that.  I feed it a
> power spectrum (a set of squared-magnitude FFT coefficients)
> that include both your "signal band" and a larger "channel
> band".  The first thing I do (convenience only) is convert
> the spectrum to dB. by computing 10*log(f_i) on each
> frequency component.  Then I split the spectrum into two
> arrays, preserving the original ordering.  The "noise" array
> gets the first third and the last third of the spectrum.
> The "signal" array gets the center third.
>
> To estimate the noise, I apply a median filter to the
> "noise" array and take the median value as the noise level.
> To estimate the signal, I convolve a FIR filter with the
> signal array, saving the result of each convolution if it's
> larger than any result previously seen.  When I get done, I
> compare the largest estimated signal component with the
> noise level plus a threshold.  If the signal component is
> larger, I open the squelch.
>
> The coefficients of the FIR filter are chosen to produce a
> Least-Mean-Squares estimate of the value at the center of a
> data window that can be represented by a 2nd-order
> polynomial.  The size of the data window is chosen to insure
> that the Variance Reduction Factor of the filter is at least
> 10 dB.

Hi John,

Sorry for the delay - in responding to the other issues in this
thread I almost neglected to respond to you.

Thanks for throwing me a bone! However, I lose you
around the point where you say

  To estimate the signal, I convolve a FIR filter with the
  signal array, saving the result of each convolution if it's
  larger than any result previously seen.

If you wouldn't mind explaining more I would like to hear more.

--Randy

"Tim Wescott" <tim@seemywebsite.com> wrote in message 
news:B5SdnXGyyocM-FjZnZ2dnUVZ_q6dnZ2d@web-ster.com...

>> If, on the other hand, the post was genuine, I think your 
>> response was entirely reasonable.
>>
>> Just my two cents.
>>
>> --
>>
>> jeh
>>
>>
> I was certainly surprised by it.
>
> I'll take your advise and de-plonk him, and see what 
> happens.
>

My sincere apologies for sticking my nose where it didn't 
belong and trying to excuse the outrageous behavior of an 
arrogant fruitcake who richly deserves exactly what he got. 
You were right and I was wrong.