## 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))

## 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.

## 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 Kozhikode

Software Freedom Day 2008 was celebrated today at Malabar Christian College, Kozhikode. The event was organized by Swatantra Malayalam Computing, in association with Malabar Christian College. The main attraction was a seminar on Language Computing, led by SMC.

There was also a GNU/Linux install fest and demo in parallel. We installed GNU/Linux on around 6-7 systems, apart from the 5 in the computer lab of Malabar Christian College. There was also an installation demo for hardware technicians. I couldn’t attend the seminar, and I’m looking forward to reading other reports about it.

One of the highlights of the day was the revival of Free Software Users’ Group Calicut, which had been dormant for over two years. Jemshid, of Ascent Engineers, the team from KSEB led by Mohammed Unais, have taken the initiative to kick start the community’s activities.

There were a few representatives from GEC West Hill and AWH Engg. College, and we’ve decided to organize a few workshops, to get some people from those colleges involved in FOSS as well, and try to create a network of college FOSS communities. Shyam put forward the necessity of a common platform for engineering colleges throughout Kerala, based on Free Software. We also have to explore the possibility of encouraging students to take up Free Software development as their projects.

Jemshid and his team had managed to contact the Malabar IT dealers’ association, and their representatives had turned up. They expressed genuine interest in migrating to GNU/Linux for the default installation in new systems they sell. They would thus be able to avoid distributing so called “pirated” software. We have proposed to arrange a basic GNU/Linux workshop for the hardware vendors. This move has the potential to start a revolution. If they can show their customers that they can do almost anything on GNU/Linux that they normally use a computer for, they’ll be encouraged to switch to it. And the customers will have someone to turn to for support.

On the whole, the event was a great success. Tomorrow, we have a small event planned in our campus. More on that later.

See other blogs and photos of the event:
Hiran

## 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…

## Liberation of Environment Knowledge Repository

The Centre for Science and Environment, in association with the National Knowledge Commission, has set up a National Portal on Environment. Read more here

I became a keen reader of CSE’s Down to Earth magazine, while I was at IUAC. It’s very informative and covers stories of development and environment from a rural perspective- many things which never appear in the mainstream media. It is great to know that the Environment Portal will make the whole Down to Earth archive freely available.