1) a system has 3(or odd number of) non-Linear subsystems, but overall it is a linear system; 2) a system has 3(or odd number of) non-Time-Invariant subsystems, but overall it is a TI system; Note that these problems are created by myself.
Can you give examples of a system that is LTI?
Started by ●October 17, 2005
Reply by ●October 17, 20052005-10-17
novellover wrote:> 1) a system has 3(or odd number of) non-Linear subsystems, but overall > it is a linear system; > > 2) a system has 3(or odd number of) non-Time-Invariant subsystems, but > overall it is a TI system; > > Note that these problems are created by myself. >As an "information sink" myself, can i say
Reply by ●October 17, 20052005-10-17
Reply by ●October 17, 20052005-10-17
"Richard Owlett" <rowlett@atlascomm.net> wrote in message news:11l7tbdbcapcv9e@corp.supernews.com...> novellover wrote: > >> 1) a system has 3(or odd number of) non-Linear subsystems, but overall >> it is a linear system;Example: 3 amplifiers that are unipolar, connected in parallel with inputs in parallel and outputs summed. "unipolar" meaning the amplifier outputs zero with either "+" input or "-" input. Amplifer "A" has output=1.0*input with input "+" and zero output for input "-" Amplifier "B" has output=0.5*input with input "-" and zero output for input "+" Amplifier "C" has output=0.5*input with input "-" and zero output for input "+" The composite is a unity gain amplifier / buffer. A practical example is a (perfect) Class B amplifier with 3 output devices with different (but very specific) gains.>> >> 2) a system has 3(or odd number of) non-Time-Invariant subsystems, but >> overall it is a TI system;It would have to be a controlled set of Time-Varying (TV) systems with the TV parts in synch - similar to the parallel amplifiers above but with TV gain according to some rule such as Varying gain amplifiers: Gain of A is: k(t) Gain of B is: j(t) Gain of C is: r(t) as long as k(t)+j(t)+r(t) is a constant, then there is no time variation. All theoretical of course.... Example: k(t)=sawtooth from +1 to +2.5 j(t)=sawtooth from +1/4 to -1/4 r(t)=sawtooth from +1/2 to -1/2 Starts at 1.75 and stays there.... or.... if you like sinusoids: k(t)=1.75 + 0.75*sin(wt) j(t)=0.25*sin(wt+pi) r(t)=0.5*sin(wt+pi) A practical example is the output of an error summing junction in a supressed carrier control system. Elements of the system are time varying but not the system itself - at least in the context of the question. Fred
Reply by ●October 18, 20052005-10-18
novellover wrote:> > 2) a system has 3(or odd number of) non-Time-Invariant subsystems, but > overall it is a TI system;How about any 3 non-Time-Invariant subsystems running on a TMS320C6416 DSK? Cheers mark-r -- "Let's meet the panel. You couldn't ask for four finer comedians - so that answers your next question..." -- Humphrey Lyttleton
Reply by ●October 19, 20052005-10-19
On 17 Oct 2005 09:02:06 -0700, "novellover" <comtech.usa.1@gmail.com> wrote:>1) a system has 3(or odd number of) non-Linear subsystems, but overall >it is a linear system; > >2) a system has 3(or odd number of) non-Time-Invariant subsystems, but >overall it is a TI system; > >Note that these problems are created by myself.I'm glad your nerve isn't in one of my teeth. [-Rick-]
Reply by ●October 19, 20052005-10-19
in article 435684c7.78482734@news.sf.sbcglobal.net, Rick Lyons at R.Lyons@_BOGUS_ieee.org wrote on 10/19/2005 13:39:> On 17 Oct 2005 09:02:06 -0700, "novellover" <comtech.usa.1@gmail.com> > wrote: > >> 1) a system has 3(or odd number of) non-Linear subsystems, but overall >> it is a linear system; >> >> 2) a system has 3(or odd number of) non-Time-Invariant subsystems, but >> overall it is a TI system; >> >> Note that these problems are created by myself. > > I'm glad your nerve isn't in one of > my teeth.hmmm. what does this mean, Rick? this just became interesting. :-) -- r b-j rbj@audioimagination.com "Imagination is more important than knowledge."
Reply by ●October 19, 20052005-10-19
robert bristow-johnson wrote:> in article 435684c7.78482734@news.sf.sbcglobal.net, Rick Lyons at > R.Lyons@_BOGUS_ieee.org wrote on 10/19/2005 13:39: > > >>On 17 Oct 2005 09:02:06 -0700, "novellover" <comtech.usa.1@gmail.com> >>wrote: >> >> >>>1) a system has 3(or odd number of) non-Linear subsystems, but overall >>>it is a linear system; >>> >>>2) a system has 3(or odd number of) non-Time-Invariant subsystems, but >>>overall it is a TI system; >>> >>>Note that these problems are created by myself. >> >>I'm glad your nerve isn't in one of >>my teeth. > > > hmmm. what does this mean, Rick? this just became interesting. :-)It's about pain and dentistry. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●October 19, 20052005-10-19
On Wed, 19 Oct 2005 16:28:43 -0400, robert bristow-johnson <rbj@audioimagination.com> wrote:>in article 435684c7.78482734@news.sf.sbcglobal.net, Rick Lyons at >R.Lyons@_BOGUS_ieee.org wrote on 10/19/2005 13:39: > >> On 17 Oct 2005 09:02:06 -0700, "novellover" <comtech.usa.1@gmail.com> >> wrote: >> >>> 1) a system has 3(or odd number of) non-Linear subsystems, but overall >>> it is a linear system; >>> >>> 2) a system has 3(or odd number of) non-Time-Invariant subsystems, but >>> overall it is a TI system; >>> >>> Note that these problems are created by myself. >> >> I'm glad your nerve isn't in one of >> my teeth. > >hmmm. what does this mean, Rick? this just became interesting. :-) > >-- > >r b-j rbj@audioimagination.comHi Robert, well ..., novellover (whose too chicken-crap to give his real name) posted two messages here recently that sounded very, VERY, much like homework problems. After his first recent post: Subject: how to prove that y=x((cos(t))^2 is not Time Invariant? when someone said his post sounded like a homework problem, novellover responded with the following amazing reply: "by the way, I created this problem myself... So please never ask if it is homework problem. NEVER!!! Otherwise it would be considered as offending. My questions are all original. And also please don't give non-meaningful replies -- like the previous two guys did. Thank you very much!" Now novellover, being an ignorant self-centered spoiled little boy spoke to us the same way that he speaks to his over-indulgent parents. He thinks that when he wants something, someone should provide it to him while he sits on his ass watching MTV. His above post was his second post, and you can see how much it sounds like another homework problem. Now novellover doesn't know enough (is too ignorant) to realize that he should pose his question, state what he's done to try to answer his own question, and then kindly seek help from the talented professionals on this newsgroup. OK, so novellover posted his first question and was criticized, and he replied in the most ill-mannered way possible. What does novellover do then, he posts ANOTHER question that sounds exactly like a homework problem!!! Ha ha ha. To me, that takes a lot of "nerve" and that's why I posted my "nerve" comment. The message in my post ("I'm glad your nerve isn't in one of my teeth.") is not really mine. I'm not that clever. I heard that line from one of my favorite TV shows. The show is "Are You Being Served?" broadcast by the reviled-by-me (but loved by you) Public Broadcast System (PBS). Actually, I can't criticize PBS too much. Their Nova Science series is, arguably, the most intelligent programming *EVER* produced on American television. By that I mean, when I sit down to eat my dinner and I'm watchin' a Sylvester Stallone movie and a commercial comes on, I start scanning through the TV channels. If I see a Nova science program on, I watch Nova and never get back to watch Sylvester kick the shit out of the "bad guys." That's tells you how much I like Nova. See Ya', [-Rick-]
Reply by ●October 20, 20052005-10-20
in article uMqdnaVnpp1iasveRVn-jg@rcn.net, Jerry Avins at jya@ieee.org wrote on 10/19/2005 21:50:> robert bristow-johnson wrote: >> in article 435684c7.78482734@news.sf.sbcglobal.net, Rick Lyons at >> R.Lyons@_BOGUS_ieee.org wrote on 10/19/2005 13:39: >> >> >>> On 17 Oct 2005 09:02:06 -0700, "novellover" <comtech.usa.1@gmail.com> >>> wrote: >>> >>> >>>> 1) a system has 3(or odd number of) non-Linear subsystems, but overall >>>> it is a linear system; >>>> >>>> 2) a system has 3(or odd number of) non-Time-Invariant subsystems, but >>>> overall it is a TI system; >>>> >>>> Note that these problems are created by myself. >>> >>> I'm glad your nerve isn't in one of >>> my teeth. >> >> >> hmmm. what does this mean, Rick? this just became interesting. :-) > > It's about pain and dentistry. > > Jerryin article 4356f28e.106586046@news.sf.sbcglobal.net, Rick Lyons at R.Lyons@_BOGUS_ieee.org wrote on 10/19/2005 22:09:> > Hi Robert, > > well ..., novellover (whose too chicken-crap to > give his real name) posted two messages here recently > that sounded very, VERY, much like homework problems. > > After his first recent post: > > Subject: how to prove that y=x((cos(t))^2 is not Time Invariant? > > when someone said his post sounded like a homework problem, > novellover responded with the following amazing reply: > > "by the way, I created this problem myself... > > So please never ask if it is homework problem. > > NEVER!!! Otherwise it would be considered as offending. > > My questions are all original. > > And also please don't give non-meaningful > replies -- like the previous two guys did. Thank you very much!" > > Now novellover, being an ignorant self-centered spoiled > little boy spoke to us the same way that he speaks to his > over-indulgent parents. He thinks that when he wants > something, someone should provide it to him while he sits > on his ass watching MTV. > > His above post was his second post, and you can see how > much it sounds like another homework problem. > > Now novellover doesn't know enough (is too ignorant) > to realize that he should pose his question, state > what he's done to try to answer his own question, and > then kindly seek help from the talented professionals > on this newsgroup. > > OK, so novellover posted his first question and was > criticized, and he replied in the most ill-mannered > way possible. What does novellover do then, he > posts ANOTHER question that sounds exactly like a > homework problem!!! > > Ha ha ha. > To me, that takes a lot of "nerve" and that's why I > posted my "nerve" comment. > > The message in my post ("I'm glad your nerve isn't > in one of my teeth.") is not really mine. I'm not > that clever. I heard that line from one of my > favorite TV shows. The show is "Are You Being Served?" > broadcast by the reviled-by-me (but loved by you) > Public Broadcast System (PBS). Actually, I can't > criticize PBS too much. Their Nova Science series > is, arguably, the most intelligent programming > *EVER* produced on American television. > > By that I mean, when I sit down to eat my dinner > and I'm watchin' a Sylvester Stallone movie and > a commercial comes on, I start scanning through > the TV channels. If I see a Nova science program > on, I watch Nova and never get back to watch > Sylvester kick the shit out of the "bad guys." > That's tells you how much I like Nova. > > See Ya', > [-Rick-] ><slackjawed> ...wow... ! (like blowing Homer Simpson's mind) :-| okay, i thought i had a complicated internet conflict. here is something that has taken way too much of my time: http://en.wikipedia.org/wiki/Bogdanov_Affair http://en.wikipedia.org/wiki/Talk:Bogdanov_Affair http://en.wikipedia.org/wiki/Wikipedia:Requests_for_arbitration/Regarding_T he_Bogdanov_Affair (unwrap this, geez i hate mu$oft) anyway, these guys are pretty famous in France, kinda like Robert Krulwich or Ira Flato for presenting science on "France 2" TV. these guys are precisely like the two "weavers of fine cloth" in the Emperor's New Clothes. it's just amazing the level of presumption and arrogance in the face of numerous damning facts. -- r b-j rbj@audioimagination.com "Imagination is more important than knowledge."
