Need proofs about digital comminucation

Jerry Avins <jya@ieee.org> writes:
> [...]

I'm with you on this Jerry. If it bothers someone that much, 
simply ignore the post. 
-- 
%  Randy Yates                  % "...the answer lies within your soul
%% Fuquay-Varina, NC            %       'cause no one knows which side
%%% 919-577-9882                %                   the coin will fall."
%%%% <yates@ieee.org>           %  'Big Wheels', *Out of the Blue*, ELO
http://home.earthlink.net/~yatescr

That description would apply to me - I might even need help understanding the 
question! I rely on posts like these, and replies to them, to add to my horribly 
meagre understanding.

But as I am also an educator in a different domain, I fully respect and 
appreciate the principle of not doing student's homework for them. For those who 
do feel moved to reply to such questions, how about an indirect clue such as 
"read Chapter XXX or Pages aaa to bbb of such and such a standard text", or even 
"if you understand topic X, you should be able to answer that question".

There are two primary types of knowledge: direct knowledge of a subject, and 
knowledge of where to look to find out about the subject. Any clues in the 
latter form are useful (even "Read the FAQ"), and would not, I think, undermine 
the "homework" principle.

Richard Dobson



Jerry Avins wrote:
....
> 
> But it's not just the gadfly student who reads the message. Suppose that
> some poor schlub like me or Owlett, with a tenuous hold on that
> particular topic and without an instructor at all, reads it and misses
> the put-on. You've done that self-taught student a disservice that
> should haunt you. It's just not worth it. The standards we use when face
> to face don't carry over to the friendly anonymity we experience here.
> 
> Jerry

Richard Dobson wrote:

> That description would apply to me - I might even need help 
> understanding the question! I rely on posts like these, and replies to 
> them, to add to my horribly meagre understanding.

At one time or another, in this subject or that, that applies to each of
us. We have a choice: learn from it to avoid deception, or get even. I
see no problem with dismissal or sarcasm without technical content.
We're not obliged to walk on eggs, but that doesn't excuse deception.

> But as I am also an educator in a different domain, I fully respect and 
> appreciate the principle of not doing student's homework for them. For 
> those who do feel moved to reply to such questions, how about an 
> indirect clue such as "read Chapter XXX or Pages aaa to bbb of such and 
> such a standard text", or even "if you understand topic X, you should be 
> able to answer that question".

That's what most here do. http://users.erols.com/jyavins/procfaq.htm is
a joint effort. It outlines our practice as the student sees it.

> There are two primary types of knowledge: direct knowledge of a subject, 
> and knowledge of where to look to find out about the subject. Any clues 
> in the latter form are useful (even "Read the FAQ"), and would not, I 
> think, undermine the "homework" principle.

In an earlier post, a reply to Eric Jacobson, I wrote

" ... On the other hand, -- here's the tie in -- I was quite willing to
accept, 'I don't know, but I know where to look it up' ... So maybe when
some of these budding engineers go for a job interview, they'll say, 'I
don't know, but I can ask the friendly folk at comp.dsp.'"

I was joking.

   ...

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

(apologies to J. Swift ;)

Since Jerry threw my hat into the ring of those who might ask student 
type questions ( not having been in engineering classroom in 30+ tears 
and wishing I knew half of what he's probably forgotten ) I've an idea.

A set of presuppositions, 'homework' posters may be:
1. lazy and incompetent
2. incompetent, knowing they are ignorant
3. competent but totally lost ( similar to #2)
4. unclassifiable independent learners ( Jerry and I )


I would suggest that the first person recognizing the post as a 
"homework question" post a response in the following form:

"This appears to be a homework question. We are willing to help 
students who demonstrate willingness to learn.

If you are a student, please identify the course and give an 
indication of why you are having trouble answering the question.

If you are not a student, please give us an idea of your background. A 
valid answer from the wrong point of view may not only be useless but 
misleading."


Also I would differ with

Jerry Avins wrote:
>  
> In an earlier post, a reply to Eric Jacobson, I wrote
> 
> " ... On the other hand, -- here's the tie in -- I was quite willing to
> accept, 'I don't know, but I know where to look it up' ... So maybe when
> some of these budding engineers go for a job interview, they'll say, 'I
> don't know, but I can ask the friendly folk at comp.dsp.'"
> 
> I was joking.
> 
>   ...
> 
> Jerry

In September 1961,

Prof. Erickson
Dean of College of Engineering
Cornell University

in his introductory lecture to incoming students that an one 
description of an engineer was 'one who knew where to find an answer 
that he did not already know'.

I was one of the incoming students, even if I never got a BSEE.

Richard Owlett wrote:

> (apologies to J. Swift ;)
> 
> Since Jerry threw my hat into the ring of those who might ask student 
> type questions ( not having been in engineering classroom in 30+ tears 
> and wishing I knew half of what he's probably forgotten ) I've an idea.
> 
> A set of presuppositions, 'homework' posters may be:
> 1. lazy and incompetent
> 2. incompetent, knowing they are ignorant
> 3. competent but totally lost ( similar to #2)
> 4. unclassifiable independent learners ( Jerry and I )
> 
> 
> I would suggest that the first person recognizing the post as a 
> "homework question" post a response in the following form:
> 
> "This appears to be a homework question. We are willing to help students 
> who demonstrate willingness to learn.
> 
> If you are a student, please identify the course and give an indication 
> of why you are having trouble answering the question.
> 
> If you are not a student, please give us an idea of your background. A 
> valid answer from the wrong point of view may not only be useless but 
> misleading."
> 
> 
> Also I would differ with
> 
> Jerry Avins wrote:
> 
>>  
>> In an earlier post, a reply to Eric Jacobson, I wrote
>>
>> " ... On the other hand, -- here's the tie in -- I was quite willing to
>> accept, 'I don't know, but I know where to look it up' ... So maybe when
>> some of these budding engineers go for a job interview, they'll say, 'I
>> don't know, but I can ask the friendly folk at comp.dsp.'"
>>
>> I was joking.
>>
>>   ...
>>
>> Jerry
> 
> 
> In September 1961,
> 
> Prof. Erickson
> Dean of College of Engineering
> Cornell University
> 
> in his introductory lecture to incoming students that an one description 
> of an engineer was 'one who knew where to find an answer that he did not 
> already know'.
> 
> I was one of the incoming students, even if I never got a BSEE.

Although knowing where and how to look something up is near the top in 
importance, it is overshadowed by knowing what to look up. Similarly, 
knowing what to look for on a spec sheet requires knowing that spec 
sheets exist. One learns a subject by building a coherent lattice of 
pigeonholes that hold data describing it. It is not necessary that those 
pigeonholes be filled at the outset, but their existence and labels 
guide us when filling is needed.

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

Jerry Avins wrote:

(snip)

>> I don't have any sympathy for people who are looking for handouts.  
>> "Teach a
>> man to fish" and all that - I'm sorry, but the OP's post was so obviously
>> desparate for a freebie that it made me cringe.  I mean come on - show 
>> that
>> the sinc-pulse is the inverse Fourier transform of whatever spectral
>> function??  That is the classic "proof left as exercise for the reader."

> But it's not just the gadfly student who reads the message. Suppose that
> some poor schlub like me or Owlett, with a tenuous hold on that
> particular topic and without an instructor at all, reads it and misses
> the put-on. You've done that self-taught student a disservice that
> should haunt you. It's just not worth it. The standards we use when face
> to face don't carry over to the friendly anonymity we experience here.

Well, if they are as obvious as the Nigerian dictator letter
then they deserve what they get.  It seems enough people fall for
that letter to keep the Nigerian government running, though.

Yes, it is a fine art.  If done right, it should be obviously
wrong after a little thought, and in time for a few laughs.

If someone writes the answer down and turns it in without any
thought at all, they deserve what they get.

I am not so sure how well I do on that scale...

I don't do it all that often, but when I do the answer is usually
technically correct, reasonable to the question actually asked,
but likely not the question that should have been asked.

I now have a copy of a book called "The Darwin Awards".  If you
have read that book you will have an idea of what I mean by
obvious after a little thought, and the results of applying
no thought to a life risking question.

-- glen

In article <3c726o5m.fsf@ieee.org>, Randy Yates  <yates@ieee.org> wrote:
>Jerry Avins <jya@ieee.org> writes:
>> [...]
>
>I'm with you on this Jerry. If it bothers someone that much, 
>simply ignore the post. 

And if you're not with Jerry, then you could also ignore the
silly replies.  Although the art form is to usually make the replies
entertaining enough to be interesting even though potentially misleading
in the domain of the homework assignment.  On comp.arch, the discussion
sometimes even leads to fruitful discussions, but usually about a
subtopic unrelated to the quiz blank which needs to be filled in.

One needs to have a clue anyway because even the answers of those
trying to be helpful are occasionally directed at the wrong problem
(or the result of a temporary brain "hiccup" just before hitting the
reply key.  I've had those... :)


IMHO. YMMV.
-- 
Ron Nicholson   rhn AT nicholson DOT com   http://www.nicholson.com/rhn/ 
#include <canonical.disclaimer>        // only my own opinions, etc.

glen herrmannsfeldt wrote:

   ...

> Well, if they are as obvious as the Nigerian dictator letter
> then they deserve what they get.  It seems enough people fall for
> that letter to keep the Nigerian government running, though.

I can spot a Nigerian scam without difficulty, but if you were to
explain soberly that the best technique for finding what I need was the
McFramistan Transform, there's a good chance that I'd set out looking
for it. That would be the last advice I would accept from you, even if
it were addressed to someone else. Better you should call me names.

> Yes, it is a fine art.  If done right, it should be obviously
> wrong after a little thought, and in time for a few laughs.

That depend on who does the thinking.

> If someone writes the answer down and turns it in without any
> thought at all, they deserve what they get.

I'm not concerned with those who turn it in, but with those reading over
their shoulder.

> I am not so sure how well I do on that scale...
> 
> I don't do it all that often, but when I do the answer is usually
> technically correct, reasonable to the question actually asked,
> but likely not the question that should have been asked.

I can sit still for that.

> I now have a copy of a book called "The Darwin Awards".  If you
> have read that book you will have an idea of what I mean by
> obvious after a little thought, and the results of applying
> no thought to a life risking question.

I know the Awards. My concern is that if they were presented out of
context, someone could mistake the anecdotes for a textbook.

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

In article <9fe525a9.0404150420.48a5d0ba@posting.google.com>,
ford <ford_usa_mustang@yahoo.fr> wrote:
>2)Show that the sinc-pulse:
>p(t) =sin((pi*t)/T) /((pi*t)/T) T^0.5 is the inverse Fourier transform
>of the spectrum 
>P(f) = T^0.5 for |f| < 1 / (2T)
>       0   for |f| > 1 / (2T)

There seem to be a infinite number of different pulse shapes which might
be the iFT of that spectrum, unless you are assuming some unstated
phase specifications as well.


IMHO. YMMV.
-- 
Ron Nicholson   rhn AT nicholson DOT com   http://www.nicholson.com/rhn/ 
#include <canonical.disclaimer>        // only my own opinions, etc.

Richard Owlett <rowlett@atlascomm.net> wrote in message news:<1085l9bod8nts82@corp.supernews.com>...
> (apologies to J. Swift ;)
> 
> Since Jerry threw my hat into the ring of those who might ask student 
> type questions ( not having been in engineering classroom in 30+ tears 
> and wishing I knew half of what he's probably forgotten ) I've an idea.
> 
> A set of presuppositions, 'homework' posters may be:
> 1. lazy and incompetent
> 2. incompetent, knowing they are ignorant
> 3. competent but totally lost ( similar to #2)
> 4. unclassifiable independent learners ( Jerry and I )
> 
> 
> I would suggest that the first person recognizing the post as a 
> "homework question" post a response in the following form:
> 
> "This appears to be a homework question. We are willing to help 
> students who demonstrate willingness to learn.
> 
> If you are a student, please identify the course and give an 
> indication of why you are having trouble answering the question.
> 
> If you are not a student, please give us an idea of your background. A 
> valid answer from the wrong point of view may not only be useless but 
> misleading."

I think most who answer "probable homework posts" here already do what 
you suggest, although perhaps not so formally as the setup above. If 
someone repeatedly experiences that his/her postst are mistaken for 
homework when they are not, perhaps a clarification of why the question 
is asked would be in place. I am not a big fan of strict rule and dogma, 
these things tend to sot themselves out in the long run.

Apart from that, I agree with those who suggest that the initial response 
to homeworks-like questions should be "look for key word this and that, 
in book so and so".

Rune