Friday, December 14, 2012

Plotting a pentagram with MATLAB.


Figure: As seen after running the code

This is a MATLAB code to plot the symbol of pentagram on a Cartesian coordinate system. The symbol consists of 1 circle and 1 pentagram - a 5-pointed star drawn with 5 straight strokes.

Basically this algorithm focuses on the getting the coordinates to draw:

(1) the circle and
(2) the horizontal line.

Later the horizonzal line is manipulated to generate the other 4 lines to form the pentagram.



Contents

The variables

n = 2^8; % Number of sampling points
t = linspace(0,2*pi,n); % Interval
noSides = 5; % Number of sides of the polygon
innerAngle = 2*pi/noSides; % Interior angle of a pentagon.

% Variables for the cirle
r = 2; % Radius
h = 0; % Transition distance
k = 0; % Transition distance

xsfact = 1.3; % Factor to extend the display range of the xy-axes.

Equations for the circle

x = r*cos(t)+h;
y = r*sin(t)+k;

Equation(s) for the horizontal line

% The length of the horizontal line
lH = r*sin(innerAngle)*2;
% Distance to the horizontal line from the center
dist_lH = r*cos(innerAngle);
% The definition interval of the horizontal line
xH = linspace(-lH/2, lH/2, n);

Rotation

Here the horizontal line from the previous will be simply duplicated for 4 times. Every point (x,y) will be multiplied with a 2D-rotation matrix.

side = zeros(2,n);
side(1,:) = xH;
side(2,:) = -dist_lH;

side1rot = rot2d(innerAngle)*side;
side2rot = rot2d(innerAngle*2)*side;
side3rot = rot2d(innerAngle*3)*side;
side4rot = rot2d(innerAngle*4)*side;

Plotting

figure,
hold on
plot(x,y, 'r')
plot(xH, -dist_lH, 'r')
plot(side1rot(1,:), side1rot(2,:), 'r')
plot(side2rot(1,:), side2rot(2,:), 'r')
plot(side3rot(1,:), side3rot(2,:), 'r')
plot(side4rot(1,:), side4rot(2,:), 'r')
hold off
axis(xsfact.*[min(x) max(x) min(y) max(y)])
title('Das Pentagramm')


Monday, December 10, 2012

Report on the Seminar: Media and Democracy



On the last Nov. 2 until Nov. 4 of 2012, World University Service e.V. (WUS) through its wing STUBE Hessen (stands for STUdienBEgleitprogramm) organized a weekend seminar with the theme: Media and democracy: On methods and means of mobilization. This event was held in a youth hostel in Fulda, a Baroque city located to the east of the state Hesse. Around 18 foreign students were present, all from numerous Hessian colleges - Frankfurt, Darmstadt, Fulda, Marburg, Giessen and so on. Three presenters delivered talks during separate sessions and it was moderated by a representative of STUBE from WUS headquarter in Wiesbaden (the capital of the state Hesse). This is the writer's report on this event.

For participation on its programs, STUBE targets foreign students from Asia, Africa and Latin America. Students of nationalities such as Mongolian, Chinese, Chilean, Mexican, Georgian, Albanian, Kenyan, Nepalese, Syria etc were spotted during this event.

During the introduction session on the day of our arrival, participants were introduced to the President of the Uni. of Applied Sciences of Fulda, Prof. Dr.-Ing. Karim Khakzar, who was accompanied by his daughter. He expressed welcome to us to the city Fulda and briefly informed us about his college.

The talks/lectures

Among the objectives of this seminar was to discuss some questions on the social media, which is proven to be a critical factor in today's politics everywhere in this world. This was so as many recent and current events - London Riot, Arab Spring, Barack Obama's Presidential Campaign etc, were known of involving a lot of mobilization via social media such as Facebook, Twitter, Reddit and so on. Therefore the invited lecturers were picked from relevant backgrounds - one graduate student of information science, an NGO activist and a journalist who happened to be an active blogger. All talks were delivered in English.

The first talk was delivered by a Vietnamese postgraduate student from Darmstadt, Mr. T.A. Nguyen. He gave a presentation which taught the pariticipants about the Internet and its impacts. Began with the introduction to the Internet, he lead us to the issues of network security, related incidents such as the London Riot and Wikileaks and censorship.

Then Mr. T. Kowohl, a law clerk by profession, talked about NGO-campaigns, mentioning some case studies from Amnesty International, of which he is a member. His objective is to show us the risks and benefits of social media froma legal perspective. He also requested us to form groups, in which the participants were to discuss make suggestions to Amnesty International on how it should conduct its campaigns everywhere.

On the next day, the final talk was delivered by Mr. J. Kucharz. who is the editor of the website http://netzfeuilleton.de/. He mentioned that he wanted to engage us into becoming our own media mogul, by starting to be active in online media. Various successful examples on online media were shown to us - bloggers, authors, YouTube-ers and so on. The Participants have also discussed the question of how they envision the media landscape of the future.

The Baroque city Fulda

That was the writer's second time coming to Fulda - the first one was in January 2009, when the writer went there as a lone wolf. Nothing much has changed since the last time. Prof. Khakzar, who the writer has mentioned above, told us that Fulda has the reputation of being the cleanest city in Hesse. It does not have much attractions for students - i.e. students find this city not so entertaining at nights, hence the weekend life of students here are relatively quiet. This, as Prof. Khakzar has alleged, is contributing to the high rate of students graduating from Fulda. The writer personally would agree with that, since Fulda is located so far away from other major cities in Hesse - 2 hours of train journey from Frankfurt alone to get there.

Nevertheless, some of the participants attending the seminar, went out during the second night in Fulda. They searched for any student-friendly place to have drinks and they have managed to spot a cosy shisha bar. The writer can't recall the price, but the writer would say it was so affordable that one could order one shisha just for oneself alone.

The conduct/behaviour of the students

Some students were found to be very articulate - actively asking questions and expressing opinions, accompanying their points with examples from their respective home countries. However a few of the participants could also be considered as rude, impolite and irritating because they talked to each other during the lectures, half as loud as the voice of the presenter in the approximately 50 m² room.

Apart from that, a few students also were found to be unfocused or diverted from the main objectives of this seminar. Some were even expressing disappointment that current political issues e.g. Arab Spring were not brought into discussion - as they thought this was the purpose of this seminar. As the writer thought this critic was unnecessary and unfair to the organizer, The writer pointed out that they have been not reading the clear descriptions of this seminar on its brochure, which was already distributed much earlier.

During the second / last night in the youth hostel, some students who were staying (not going to the shisha bar), used the seminar room as a place to put on some loud music and dance. They were having fun until one 40-year-old-plus man, who happened to be another guest the hostel, came to them and gave a threat, telling them to stop partying or he'll complain tomorrow to the hostel admin, saying that this would be their last time to come here. That was very ironic, since this hostel was supposed to be a youth hostel.

Summary

This seminar can be considered as successful in achieving its objectives. Participants were exposed on the availability of social media as a very useful tool in promoting their causes - be it political or anything else. Participants generally found the conducting of the seminar in English very favorable. The seminar has motivated the writer to be more active in using social media, hence by being active again in writing on this blogspot. The venue - a youth hostel in Fulda - it was a good place to hold a instructive events such as this, but located very far from the central  part of Fulda.