Geschafft! Am 26.10.2010 gab ich nun letztendlich mein Kolloquium (Präsentation meiner Bachelorarbeit) im Rahmen der Vorlesung Aktuelle Themen der IT-Sicherheit. Mein Vortrag war sehr gut besucht mit ungefähr 80 Studenten aus dem 1., 3. und 6. Semester Informatik, sowie von ein paar Studenten des Elektronik-Masters wie ich am Tag darauf beim Kendo Training erfahren hab (Stichwort: Die Welt ist klein).

Die Präsentation hab ich an meiner Hochschule, der HTW Aalen, auf deutsch gehalten und dem unmittelbaren Feedback mancher Teilnehmer, die auf mich zukamen nach der Präsentation, zu schließen kam Sie auch ganz gut an.

Im Folgenden die Präsentation, jeweils im PPTX und PDF Format:

• PowerPoint Präsentation (PowerPoint 2003)
• Präsentation (PDF)

There was not much going on here over the course of the last year for I was busy working on different kinds of things, one of them being my bachelor thesis and getting my degree. As of this month, I finished my thesis, so there will be coming more in the future as I finally got some spare time to pursue projects in my spare time.

Let the games begin!

One of those projects I wanted to pursue for a very (very very) long time is game programming. Actually, that’s what got me interested in programming in the first place. Strange thing I didn’t try it earlier, don’t you think?

Anyways, better late than never and I’ve been working on a Space Invaders-clone for the past weeks with some dear friends of mine. Now, Space Invaders does not sound too exciting, but everyone has to start by taking little steps, and those are mine.

On the other hand, this little game won’t be coded in a quick’n'dirty manner, but with a fully-blown component-based architecture backing it up (and a hell of a threaded resource manager written by Patrick Bader), so it’s not too trivial on the technical side of things. I plan on releasing the source code (it’s written in C# utilizing SlimDX, btw) when its finished, so look forward to it if you’re a programmer interested in game architectures.

As a gamer, you may also look forward to it as this game will feature some nice sprite graphics created by Daniel Kwast and Isolde Scheurer.

The app utilizes the GNU Crypto library. Alas, the Android Development Tools (ADT in short) could not convert the JAR library file provided by the GNU Crypto website into an Android-compatible JAR file, so I had to include the source of the GNU Crypto project itself. To limit the impact on the size of the app, I only included what was needed by my app (the hashing facility) and left out the rest of the GNU Crypto project.

Though primarily written to manage and generate lists of the OTPW package right now, the app architecture was designed with extensibility in mind. It should not be too hard to add support for another OTP-System. The basic components are well encapsulated and the generation facility was written in a way that allows new classes to be added to handle other OTP systems. Only the generation GUI needs to be extended to accommodate for other possible OTP-Systems.

Future development

For the time being I won’t continue working on this app. Also, I did not distribute it in the Android Market as you need a credit card to do so and – though some might not believe it – I don’t have one. If you are interested in continuing the development of this app, feel free to contact me so we can talk about it. I’m sure we will be able to come to an agreement.

Downloads

• Documentation (PDF, english)
• Android Package (APK) file of the app
• Source

Disclaimer

It was written to the best of my knowledge, though I can’t guarantee it’s perfectly free of errors. Furthermore, the disclaimer of this blog applies.

The main goal of this project was to develop an algorithm to approximate an optimal tour for the traveling salesman problem, which is in short as follows: A salesman wants to visit X cities under the following conditions:

• every city must be visited exactly once
• the tour has to be a round trip

This is a NP-complete problem, meaning there is no efficient algorithm known to solve it in a worthwhile timeframe. Since nobody wants to wait for several years to get an optimal tour, there are some approximation algorithms which are rather good. As multi-core processors are becoming more and more common, programming applications that utilize multiple cores has become an important trait.

This is where genetic algorithms come into play: Offering intrinstic parallelism they’re well suited for parallelization. Also, they are very general in nature: All that’s necessary is to encode the problem in a way the genetic alorithm can handle it. The algorithm does not need any problem-specific information, although it could be used to enhance the results.

The TSPLib was used for sample data, which is pretty nice as there are best known solutions to it.

Build Environment

The program was developed in Linux using eclipse CDT 5.0.1 and CMake 2.6, so this is the recommended environment to build and run it. It also utilizes OpenMP and TR1 for shared pointers, so make sure your compiler supports it. For further details, see How to build.

Building under Windows

By default the build environment is set to linux to compile. If you want to compile it under windows, you have to set the appropriate define in the config.h file:

//#define LINUX
#define WIN_32

Also note that this is a console application, so make sure you’ve set your IDE to the correct system.

Downloads

• Documentation (PDF, english)
• How to build (PDF, english)
• Binary (Linux)
• Binary (Win32)
• Source

Disclaimer

It was written to the best of my knowledge, though I can’t guarantee it’s perfectly free of errors. Furthermore, the disclaimer of this blog applies.

Basically, this is a simulation of a two-legged combat vehicle called ‘BattleMech’ (in short ‘Mech) which generates lots of heat while fighting. ‘Mechs are equipped with heat sinks to dissipate the excessing heat they are generating. When the excess heat is just too much the heat sinks to cope with they can flush coolant to increase their cooling rate, as long as the coolant tanks don’t run out of it. Heat sink’s effectiveness is affected by the environment (they have a harder time to dissipate heat in the sahara as they would have at the north pole). Also, if the heat exceeds a certain threshold, the heat sinks may take some damage—when they are, their effectiveness is affected.

You can take a look at my implementation by downloading the source files given in the download links below. I’ve also created a little test program (Windows binary), which just generates some random input data for the Mech Heat Tracker and prints the results to the console.

Download

• Binary (Windows)
• Source (Windows)

I want to emphasize that this work is only an introduction on the topic and therefore does not contain manuals or step-by-step tutorials on how to set those features up, rather explaining how they work as well as elaborating their advantages and disadvantages.

Disclaimer

This document was completely written in german. There is no english version available. It was written to the best of my knowledge, though I can’t guarantee it’s perfectly free of errors.

Download

• Security mechanisms in Linux (PDF, german)

Sample Code:

<?PHP
	function hello($name) {
		echo "hello " . $name;
	}

	hello("world");
?>