Entries by Stephan Paukner

Hautamaeki? Oder haut a net?
Mogadischu? Oder mog a’s net?
Samariter? Oder samma kane?
Simmeringer? Oder simma kane?
Renitent? Oder rennst du?

I’m using Linux for some years now. It provides a very robust server operating system. With Linux you have high performance file systems, intelligent process handling, transparent configuration and very stable server software. You can have Linux for free, its software is open-source, thousands of programmers care for quality assurance. It really works.
But some think that Linux could replace Microsoft Windows on the PC. Windows is a great gaming platform, and some admins even go that far and use it on their servers! Similarly, some Linux enthusiasts placed Linux onto their PC or notebook. They believe, the time is now ripe for a desktop revolution. I also tried it, but, in my eyes, Linux is not usable on the desktop for ordinary people as long as:

• You have to know that there could be a hidden file named .lpoptions in your home directory which disturbs your printing system. Whatever you set in the print dialogs, that hidden file overrules your settings and makes you cursing why the prints are always rotated by 90° and therefore only covering one half of the paper.
• You have to know the exact names of your programs. Those names almost won’t have anything to do with their function, e.g., if you’re searching for an audio editor, you have to know that it’s called Audacity. If you want to use a video editor, install the package Cinelerra. If you want to use a CD-burning program, it has the dazzling name K3b. Your file-browser is called Nautilus. Or do you prefer Konqueror? Would you guess the function of Rosegarden or Lilypond? What about Evolution? Liferea? This list doesn’t end. Ask a Linuxian about which software you could use for this and that, he/she’ll answer you to use Crixycraxy, or something like that, and you wouldn’t remember that name even if you used that software. And: Your favorite web-browser Firefox might be called Iceweasel on some Linux distro. This is because Linux freaks don’t like software which becomes too popular.
• Programs don’t show error messages on the X-screen. Imagine you click on an icon to launch a certain program, but then nothing happens. You do it twice, nothing happens. WTF? You have to open a terminal, type in the name of that program (Do you know its name??) and then figure out the error messages on the terminal.
• You cannot play MP3s and DVDs legally on your PC. Boom! If that ain’t a reason not to use Linux!
• You cannot simply use the power-saving features of your notebook. This is because hardware manufacturers simply don’t support Linux. You have to search the web if some hacker already found a hack, but it would only work for another model, not for yours. And if something works, then only half. If you break your notebook, you’re on your own, because the hacker didn’t grant you warranty. GPL is like: Be so free, use it so freely, but never be safe.
• You cannot simply use WLAN. You have to put up another Linux box with a WLAN adapter and set up a VPN connection between your PC/notebook and that Linux box. At least that is what Linux gurus tell you to do.
• You have to be a real Linux expert to set up a GPRS modem connection via Bluetooth to your cellphone. There’s no software which does it for you. I can do it! Be sure your USB Bluetooth adapter is recognized and that the bluez-utils are installed and the kernel module is loaded. Curse around because you don’t manage to set up the Bluetooth connection because of that stupid PIN. Google around. Finally ping your phone successfully and copy its cryptic hardware number into the configuration file. Then set up a rfcomm mapping, the device /dev/rfcomm0 is then your modem. You have to configure a profile with the correct modem codes for use with GPRS. Then use it for your dialup configuration. It’s just as simple!

Linux is for hackers only. It always was and will always be so. Linux freaks waste their time compiling software, reading hundrets of e-mails on a text terminal, use IRC and Usenet and even browse the web in text terminals. Linux users don’t play games, at least no graphical ones. OpenGL is for stylish screensavers only.
Linux enthusiasts are pretty cool. They are hackers. Lots of textlines scroll over their X-desktop, just like in The Matrix. They encrypt their e-mails. If you want to be as cool, become it on your own. If you ask one of them to help you with your problem with Linux, they are unpolite and correct your misspellings. Linux freaks are assholes. I am one of them.

Um einmal niederzuschreiben, was ich bei der SOL4-IT alles so gemacht habe, habe ich mir eine Liste meiner Tätigkeiten erstellt. Das wäre ein Grundgerüst für die nächste Bewerbung. Um nicht zu viel zu verraten, habe ich hier die jeweiligen Kundennamen nur abgekürzt.

Beschäftigungszeitraum: 10.07.2003 - 31.01.2007.
Alle Aufgabenbereiche wurden in direktem Kontakt mit dem jew. Kunden abgewickelt.

Lotus-Notes-Development

• Ab 2004/06: S. S. AG: Einführung eines DMS unter Analyse und Abbildung der Kundenworkflows. Umsetzung umfangreicher Anpassungen und Erweiterungen. Implementation und Integration einer Artikel- und einer Projektverwaltung. Erweiterung des Helpdesksystems. Projektaufwandsanteil >110MT.
• Ab 2005/04: Implementation und ständige Weiterentwicklung des hauseigenen Produkts “Visual Team Calendar” in Kooperation mit der AdHoc, s.r.o. (Prag, CZ). Anpassungen für C. Z. GmbH (Geräteverleih), A. A. und A. A. GmbH.
• 2004, 2006: E. Reiseversicherungen: Implementation einer automatisierten Verarbeitung von Attachments eingehender Mails, Sortierung nach konfigurierbaren Kriterien, Datenextraktion. Erweiterung um FTP-Transfer.
• A. A. GmbH: Übernahme der Betreuung des DMS. Migration des angepassten DMS auf neue Version. Implementation und Integration einer Verkaufsunterlagen-Verwaltung.

Linux-Systemadministration

• Teilhabe an der Hauptverantwortung für den Betrieb des Webhostings, verteilt auf 4 IBM-Rechner: DNS von über 150 Domains, ca. 140 Webauftritte, ca. 330 User, Mailserver mit Virus- und SPAM-Filter, J2EE-basierendes CMS, Lotus-Domino-Hosting.
• Installation und Erweiterung eines Überwachungssystems inkl. differenzierter Alarmierung bei Ausfällen.
• Migration (Konsolidierung) von PostgreSQL auf MySQL.
• Wartung der firmeninternen Systeme.
Kundenprojekte:
• A. A. GmbH: Selbstständige Vorbereitung und Abhaltung einer fünftägigen Linux-Schulung für 4 Personen.
• F. H. GmbH: Wartung und Erweiterung des Mailservers durch SPAM-Filter.
• R. F. GmbH: Systemmigration auf RAID-Festplattenverbund, Backup-Implementation mit Transfer auf IBM AS/400-Rechner.
• Dr. K. & M. GmbH: Systemmigration auf RAID-Festplattenverbund, Lotus Domino Backup-Szenario.
• S. S. AG: Migration eines J2EE-basierenden CMS inkl. Webauftritt von Suse Linux auf Debian GNU/Linux.
• M. Handelsges.m.b.H., G. & H. OEG: Migration eines Windows-Fileservers auf Linux/Samba.

Web-Development

• 2003: Wartung, Betreuung und Erweiterung des Immobilienportals FMH (G. & H. OEG) in PHP/MySQL, z.B. Erweiterung der Suchfunktion.
• 2004/03-2005/03: Wartung, Betreuung und Erweiterung des Hotelportals H4Y (E. Verlagsges.m.b.H.) in PHP/MySQL und tw. JavaScript/DOM, z.B. Mehrsprachigkeit, Mitgliederbereich, Newsletterkampagnen, Veränderung der Reihung und Hervorhebung von Suchergebnissen, Erweiterung des CMS, Bannerverwaltung, Bannerrotation.

I stop working at SOL4-IT at the end of January 2007. From that time on I can work 100% on my Master thesis! But I don’t have to live from my savings: I’ll apply for a final degree scholarship (Studienabschluss-Stipendium). For 6 months I will (or could) be promoted with €1000 every month, with an additional (unpaid) timeframe of 6 months until I’d have to pay the amount back if I hadn’t finished by that time. I’ll not be allowed to hold any job during that phase. That gives me everything I need for a scientific work.

Linux sucks on the desktop. I’ll write a rant on this soon.
In Nautilus, suddenly, one day, after a general (apt-get) upgrade, there were no more thumbnails generated for new JPEG images. When I clicked one of the icons, instead of opening the image in the viewer ‘eog’, a message raised, saying

The filename “IMG_1234.JPG” indicates that this file is of type “jpg document”. The contents of the file indicate that the file is of type “JPEG image”. If you open this file, the file might present a security risk to your system.

followed by the usual security-blah-blah. I couldn’t examine what the cause was, until I finally stepped over a posting telling that the file ~/.local/share/mime/globs contains an overfluid entry. Remove that entry containing the string ‘jpg’.

(Q26) Meanwhile, I know that a convolution of one function with another function means that will be “-smeared”, and vice versa. I visualized some convolutions using Octave. I was prepared to implement for two vectors, but then stepped over HGFei’s conv2fei which makes the surprising use of the identity ; I wouldn’t have come to the idea to do it this way, you only have to multiply two FFT’s and then do the inverse FFT.

First I convolved a square with a small Gaussian—this is nothing less than a Gaussian blur:

Note that the blur would already occur even if the second object were solid! Look at the square convolved with itself:

Then I watched how these bars convolve with each other:

Notice how the blurness shrinks when the two objects can’t overlap much.

66. What are Fourier multipliers?
67. What are Frechet spaces? Why are and not Banach, but only Frechet?
68. Is there a difference between and in HGFei’s notation?
69. Why is ? (There’s a relation to Q2.)

(Q15) I’m gonna show you some cool Gabor atoms on . First, the function , as described previously, indeed looks like this:

See how the value of the frequency changes with the length of , and the direction with the orientation of , just as described previously.
In the STFT, these frequencies get reduced locally by an “envelope function”. One could take the Gaussian window to achieve this:

And now these are the modulated Gaussians, whose set of translates across forms the building blocks for Gabor analysis on :