...discuss.

death? cake? easiness? shereallytaughtnothingverywelltheentiresemester and now here we are?

i don't think i'd ever seen the class as large as it was today, excluding the first day and test days..

11/16/2005 11:44:00 PM

yeah, today was the first time i've been since last test, same goes for a guy i was sitting with, another friend still didn't go lol

not death, but not a push over like exam 1

the first exam coulda been taken by 1st graders

[Edited on November 17, 2005 at 1:15 AM. Reason : .]

11/17/2005 1:15:17 AM

I doubt it will be hard if you pay attention at all.

Which i dont

but nothing hiway and i cant solve in a night before drink beers session

hell

its how we did the project

11/17/2005 2:35:52 AM

I was thinking it would have been really funny if we had asked her to review on Friday. Then at least I could have studied some things over the weekend...plus it would have been hilarious for all those people to show up yesterday and when they would have asked about the test, she would have said, "We did review on Friday. Today we continue Chapter 4."

I wonder how many people would have gotten up and left...

This test (I hope) shouldn't be bad. She seems like a professor who wants to actually test you on simple concepts - not can you solve this huge and ridiculous Z-transform. It seems like if you read over the notes, write everything down on your three sheets, and do the homework problems, should be *cue Viniotis* "a piece of cake."

11/17/2005 10:28:55 AM

^

If you show up every day to that course, the joke is entirely on you.

11/17/2005 11:44:42 AM

[Edited on November 17, 2005 at 12:39 PM. Reason : .]

11/17/2005 12:38:48 PM

Quote :

"If you show up every day to that course, the joke is entirely on you"

301 was definetly harder than this class. With that said yesterday was the first time i went to that class in about 3 weeks, so now I have to study for one day boo hoo, i bet the hardest question will be taking the partial fraction of a quadratic with two factors

11/17/2005 1:26:19 PM

there is a 421 test tomorrow?

and what is this "class" i hear everyone speak of?

[Edited on November 17, 2005 at 3:22 PM. Reason : /]

11/17/2005 3:20:47 PM

Quote :

"i bet the hardest question will be taking the partial fraction of a quadratic with two factors "

it will be something like

1
---------------
(z+2)(z^2+5z+3)

where A/ z+2 is some transform from the table and B/ z^2+5z+3 is some transform from the table


it would have been pretty gay had we had to write all those things out. thank god someone kissed ass.

[Edited on November 17, 2005 at 4:49 PM. Reason : .]

11/17/2005 4:48:31 PM

hmm might be a lil worse than i initially planned for

.... contingency plan may be used aka: all nighter

11/17/2005 9:39:44 PM

^yeah thats my plan. but only because i have another test as well in the morning. i'm not too worried about 421 test. but 2 tests in 1 day sucks

11/17/2005 10:26:11 PM

hhhmmm, this might be the first test i fail in a few years*

*drug tests not counting

11/18/2005 12:56:10 AM

11/18/2005 1:03:56 AM

^
Now we're getting somewhere

11/18/2005 1:17:03 AM

dbl post

[Edited on November 18, 2005 at 1:17 AM. Reason : .]

11/18/2005 1:17:45 AM

are we ready?!

just make sure to bring your clear glass bottle of vodka to sip on

[Edited on November 18, 2005 at 12:14 PM. Reason : .]

11/18/2005 12:13:41 PM

^

10-4

11/18/2005 12:31:19 PM

That wasn't that bad

Of course, I was like the second person out of there... which may or may not be a good sign

11/18/2005 1:52:38 PM

normally im one of the first ones out, not for this

but from talking to people i think i did well

11/18/2005 2:28:39 PM

the average is going to be looooooooower

11/18/2005 2:46:55 PM

I think I got something in the range of 60-100

11/18/2005 3:31:59 PM

answers shoulda been:

1. H(z) = Y(z)/X(z) simple to evaulate those two from the problem.. if you couldnt manage part um

2. doughnut 1/4<|z|<1/3

3. a. poles at -3 and 1/2, zero at -2
b. h(n) = 5/7*(1/2)^nu(n)+2/7*(3)u(n) - if i remmeber right.. the 3 may be negative
c. i messed this one up, but its the same as b
4. not sure about this one but i had yes yes no yes yes no (i know i missed one of the first two yes's(it's supposed to be no) but i dont remember the question order)

11/18/2005 3:32:21 PM

Quote :

" c. i messed this one up, but its the same as b "

I thought for stability, the second part had to be anticausal since (-3)^nu(n) is unstable. So for a stable system, the first term is causal (as in part b), and the second anticausal. So h(n)=(5/7)*(1/2)^nu(n)-(2/7)(3)^nu(-n-1).... at least that's what I put.

I was so stupid on number 2: for some reason I was thinking 1/4 > 1/3, so I said the ROC was an empty set

On 4, I got stable, not causal, no, yes, no (converges to 4)

It's definitely stable and not causal. It converges to 4, and the system had an y(n-1) term in it so it's not causal.

The zero input response has one pole, but the zero state response has more.... I'm really not sure at all about that part, but that's what I said.

[Edited on November 18, 2005 at 3:47 PM. Reason : sgeohuf]

11/18/2005 3:43:47 PM

^ that's exactly what i put... my roomie said i was wrong though

i hope we're right

for #3 that is

although i know it's 2/7 i somehow got 10 for my B or C2 whatever you called it i better not miss much for that though



[Edited on November 18, 2005 at 3:51 PM. Reason : #3]

11/18/2005 3:47:01 PM

Quote :

"for #2 that is"

You mean number 3, right?

I don't think they'll count off much for a minor partial fraction expansion error.

I hope they don't count too much off for my boneheaded proclamation that 1/4 > 1/3

[Edited on November 18, 2005 at 3:50 PM. Reason : much]

11/18/2005 3:50:28 PM

i don't think it was a doughnut...that negative signal was to the ^-n, so ... eh, i don't know.

11/18/2005 4:06:26 PM

^^i think you may have missed a lot

11/18/2005 4:28:52 PM

Wouldn't surprise me

11/18/2005 5:24:50 PM

sorry that came out a little too harsh haha, that material leaves a lot of room for small errors i think. The reason i say that is because I think in number for the system was unstable, it converges, yes, but that doesn't mean it's stable, it has to converge to 0 in order to be stable. think of the unit step, this is constant at 1, but is not absolutely summable. Also the roc for the unit step, which was x(n) in the problem, is z>1, which means the unit circle is not within the roc.

Also, i believe it was causal, eventhough it depended upon an initial state, the function didn't index, or predict future occurences, so i believe it is still causal eventhough it y(-1) is used in finding the zero-input response

Also, on the doughnut, i got the range to be from 1/4 to 3, not 1/4 to 1/3, anyone else get this? im not sure about this part, hopefully there'll be a curve

11/18/2005 5:33:19 PM

hehe no prob, either way im sure i passed

and since i've been to the class one day bout 2 weeks in, day before 1st test, day before 2nd test and today and have an A average at least before this im still happy

11/18/2005 5:54:46 PM

yea, see my problem is that i haven't really been doing the hwks that much, and i didn't finish the project, then she bumped of the weights on both of those, so i kinda needed this test, oh well

11/18/2005 6:02:28 PM

Quote :

"2. doughnut 1/4<|z|<1/3"

I think you meant 3 like sNuwPack said. It was (1/3)^(-n). So you invert that and get 3...so I was one of the people who got a "doughnut" ROC.

Quote :

"It's definitely stable and not causal. It converges to 4, and the system had an y(n-1) term in it so it's not causal."

Hmm I thought the causality wasn't determined by the y terms, it was just determined by the input x. Therefore if you had x(n+5) or something in the future, it's not going to be causal. I'm pretty sure this is correct....at least I hope that's correct... But I agree, it does converge to 4 (though we just had to say whether it converged to 0).

11/18/2005 7:43:23 PM

Yeah, so I'm an idiot

Alas

11/19/2005 1:26:06 AM

also
on the last problem
THE NATURAL RESPONSE IS NOT STEADY STATE
that would be the transient part of the final output ;x

11/19/2005 1:33:34 AM

Yeah, I had that one right on my notes (I may have gotten the order wrong when I posted it up there)

11/19/2005 9:59:01 AM

this thread makes me depressed

that class took stuff i knew that i knew and twisted it and cut it up and mangled it and then gave it back to me and was like PERFORM BITCH and i was like O_o i overstudied and thought too much.

11/19/2005 10:46:29 AM

Quote :

"THE NATURAL RESPONSE IS NOT STEADY STATE that would be the transient part of the final output ;x"

Yeah I looked at that question and thought, "......is there some trick here?" after looking at my sheet.

I think that was in response to all the people saying on Wed. at the end of class that the transient was due to the natural response yet everybody yelled out "FORCED!!!"

Quote :

"Yeah, so I'm an idiot"

I started looking through the 421 and 301 book and the notes because I couldn't remember. I could have sworn causality is just for the x[n] terms...but I guess we'll find out soon enough.

So who wants to start guessing how long it'll take her to grade this test? I'm thinking we'll get an e-mail on Christmas Day letting us know the tests are graded and which TA graded it.

11/19/2005 12:53:04 PM

haha, yea i was kinda confused about the natural response one too, bc i was like i thought it could NEVER be reffered to as the steady-state, but whatever, does anyone remember the equation for number 4, did the x(n) terms have future values? for some reason i thought it was x(n-5) not x(n+5) like someone referred to, but maybe im wrong, and that would make me sad.....but only a little bit

11/19/2005 5:27:45 PM

^ I think you're thinking of another problem on the test. The last problem (I think that would be number 4...but then again I had to stop and think) didn't have a x(n-5) or x(n+5) term. I think the first problem had a x(n-5) term in it. If I remember right, 4 was...

y(n) = 1/2 y(n-1) + 2x(n) where x(n) was the unit step and then y(-1) = 1 (?).

[Edited on November 19, 2005 at 9:49 PM. Reason : .]

11/19/2005 9:48:58 PM

i must have fucked up hardcore because i have no idea what you guys are talking about

i was also the last person to finish

i looked up and saw myself, and people of color

all 4 of us.



wait ROC with a fraction and 3 sounds familiar

as does 2/7 as a partial fraction number


[Edited on November 19, 2005 at 9:57 PM. Reason : . maybe got a 30]

11/19/2005 9:55:25 PM

yea, none of my answers felt right. NONE...i tried to study wayyy too much stuff for this. my sheets were all in depth and with all these special cases on them, so i made even the easy stuff much harder than it should have been. i finally finished (way later than i thought i should have) and then tried to like...double check stuff, and basically decided that i did absolutely every problem wrong, then i turned it in and walked out

not lookin forward to getting these back...

11/19/2005 10:16:35 PM

Quote :

"but I guess we'll find out soon enough."

You have to understand: when I said that I am an idiot, I was basing this on all my experience of being me. Whether or not I happened to get that problem right, I will in fact, remain an idiot.

11/19/2005 11:39:55 PM

lets play, the i beat i got higher then lower then game

i bet i got higher then

hiway
pimaster

lower then
snuwpack
snuzzbff

11/20/2005 12:03:32 AM

i bet i got higher than quinn.

11/20/2005 1:27:47 AM

11/20/2005 2:40:41 AM

I'm a gambling man, so I'm gonna go ahead and claim top prize

11/20/2005 5:17:16 PM

THAN not then

jesus you people

11/20/2005 5:33:34 PM

Pi Master - the "guess we'll find out soon enough" comment was in reference to we'll find out soon enough whether the system was causal or not.

I either got everything right or I did everything wrong. I just don't think there's any way I could have done anything but those two extremes.

11/20/2005 6:48:44 PM

hahaha "you people"

it was me

not people

christ its the internet

if anywhere

call me out to my name here

11/20/2005 6:56:38 PM

Quote :

"I either got everything right or I did everything wrong."

Story of my life




I bet I've gotten higher than Quinn ever has... just probably not on this test

11/20/2005 7:49:36 PM