## NITC Past and Present

I was going over the area of NITC in Wikimapia, when I suddenly realized that the satellite images of the place were somewhat old. In fact, it shows the campus in its state even before I joined the college, but not much older, since the only difference is the absence of the Central Computer Centre and the new Mini Canteen.

Over the last four years I’ve seen acres of forest give way to concrete structures and I thought I’d just highlight the changes I’ve seen on the map. These estimates are very rough and have been made from my countless walks around the campus. They are very conservative estimates and I suspect a lot more area has been cleared, as I have not even been to each and every corner of the campus.

## Nothing Short of a Miracle!

That’s what happened today. The occasion was a cultural night arranged by the Staff Club of NITC (no one knew one even existed, till today!). Some of the faculty got together and wrote a drama to be staged tonight. I learnt about it from Deepak sir’s blog a few days ago, and that in itself seemed like a miracle. But the actual performance was nothing short of unbelievable, to say the least! It was fantastic. About the drama itself, I keep that for another day. I’m just too dazed by that performance to analyze it critically. Besides, Deepak sir has promised to make the script and video available.

I always knew that the faculty members were fantastic people outside the classroom, but hats off to them for this wonderful performance!

## DSP Lab – Week 1

### Constructing the Complex Plane

Suppose we have a sampled signal defined by the sequence $h(n)$, $n=0,1,2,...,N-1$

Its Z- transform is given by $H(z) = \sum_{n=0}^{N-1} h(n)z^{-n}$ .

It maps the original sequence into a new domain, which is the complex plane $z=e^{sT}$ where $s=\sigma+j\omega$ is the parameter in the Laplace domain and $T$ is the sampling period.

The $j\omega$ axis in the $s$-plane maps onto the unit circle with centre at the origin in the $z$-plane. So the value of $H(z)$ at different points on the unit circle actually gives the contribution of the frequency component given by $\angle z$, in the original signal.

This, in effect, gives the Discrete Fourier Transform of the sequence. Consider the following example:

%original sequence
h = [1,2,3,4];

%number of chosen points on the unit circle
N = 64;

%define the chosen points
z = complex(cos(2*pi/N*(0:N-1)),sin(2*pi/N*(0:N-1)));

%evaluate H(z) at each point
for i = 1:N
H(i) = 1+2*z(i)^-1+3*z(i)^-2+4*z(i)^-3;
end

%plot the unit circle
plot(z)

%plot the value of H(z) along the unit circle
figure
plot(abs(H))

%plot the N-point DFT of h(n)
figure
plot(abs(fft(h,64)))


This example computes the value of $H(z)$ at 64 uniformly spaced points on the unit circle and compares it with the 64 point DFT. We can see that both (fig. b & c) are identical.

unit circle

value of H(z)

abs(fft(h))

## Digital Signal Processing Lab

We are very lucky to have Abhilash sir in charge of DSP lab this semester. I really used to enjoy his classes during the Signals and Systems course in the third semester. In fact it’s the only course so far, in which I’ve felt like paying attention. I think I will document whatever we do in the lab, on my blog, when I get time.

## Freedom Walk at NITC

It was almost midnight when the Freedom Walkers arrived here on Wednesday. They were thouroughly worn out from the long long walk from Thamarassery. They had dinner from our mini canteen, and then I led them to the rooms in PG-2 hostel which Sandeep sir from the Electrical department had booked.

Next morning, a few S3 guys and I went to meet them. We had a small gathering in their room and discussed what all we could do to spread Free Software here at NITC. Since all of us except one were from Electronics, Jemshid suggested that we could get started on some Embedded GNU/Linux work. We can think of conducting workshops to get people interested in it.

Prasad talked about the Freedom Toaster they had made, and suggested that we could try to make one with a vending machine, as a project. They said we would have their support if someone is ready to take it up.

It’s too bad we couldn’t organize a more elaborate meeting with the Freedom Walkers, because of the exams. But we’ve got some pointers to think about, when we sit down to make a concrete plan regarding the FOSS Cell activities.

## RMS lecture at NIT Calicut

As a part of this year’s Tathva, the technical fest of NIT Calicut, there will be a video conference with Richard Stallman.

Topic: The Free Software Movement and the GNU/Linux Operating System

Date: 25th October

Time: 9.00 am to 11 am

See http://tathva.org/lectures.gl.php?PHPSESSID=1426bc5eea73716979ab0c62978e053f for more details.

## GNU/Linux Install Fest at NITC

As the first activity of the upcoming FOSS Cell NITC, we organized a GNU/Linux install fest on the occasion of Software Freedom Day. Around twenty people turned up during the day. The only undesirable part was that a couple of laptops, after installing Ubuntu, couldn’t boot Windows. Got to sort out their issues soon. We’ve set up a technical support mailing list for people to post their problems.Considering that it was the first ever event by our FOSS Cell, it didn’t go too badly.

## Software Freedom Day at NITC

We are planning to celebrate the Software Freedom Day through an install fest and demos. There was a meeting today to get some volunteers for the event, and around twenty S3 students turned up. Only some of them have used GNU/Linux before, and they have been given the task of familiarising the others with it before the event. We are also hopeful of launching our FOSS Cell officially on that day. More about the event as it materializes…

## Exams… (again)

It’s something I’ve written about a lot in the past, and am sure to write a lot in the future, as well! Well, this time the occasion is the end of the first Interim tests of the fifth semester. This semester is better, in that we have only five core courses, the sixth being Environmental Studies.

Last semester I got into the habit of doing something I’d never before done in my life- cramming junk into my head just before the exams. The level of my motivation was so low, and those of my ignorance and indifference to the subjects were so high that whatever grades I got that sem were due to this last minute mugging up. (I should mention that I had got through the previous three semesters without disaster, mainly because of the fundamentals acquired while at school, rather than any effort on my part.) But it was sheer mental torture.

I’ve decided that I’d do nothing of the sort this time round. That I’d let myself explore the topics at my pace and discretion. Of course, it doesn’t guarantee good grades-the converse, quite possibly. But I think that’s the only way ahead for me. Learning everything taken in class exhaustively is out of the question. This is not school. That would probably drive me mad. Learning something for an examination is mental torture. And it’s against the purpose of exams.

At least now, I love all subjects and feel a real thirst for knowledge. That’s a big improvement from last sem. As for grades, I couldn’t care less so long as I pass.

## First Meeting

Fifteen of us, including Deepak sir and Murali sir met today for what was the first meeting of the FOSS cell. It was notable that there were six S3 guys, from Electronics, Computer Science, Electrical and Civil, all of them motivated from last year’s FOSSMeet. We got to know each other, and decided on the things to be done immediately for setting up a group. It’s a new beginning and I’m looking forward to it. The S3 guys seem to be an enthusiastic bunch and there is enough reason to be optimistic about this new venture.