Omar Abo-Namous

Contact Form for wordpress

admin — Tue, 23 Feb 2010 15:39:32 +0000

For a client of mine, i’ve been using the PEAR-package HTML_QuickForm which is ’superseded’ by now and isn’t compatible to php 5.2, whereas the followup package HTML_Quickform2 is still in alpha state. Since the client switched his server and that is running php 5.2, i had to come up with a new solution. I tried [...]

Scavenged pen-plotter Roland DG DXY-990

admin — Fri, 20 Nov 2009 13:00:01 +0000

Yes! I've managed to scavenge an old pen-plotter that was obviously gathering dust down in the basement of our institute. Last time i've seen such a plotter was in the 1980s at the institute where my father used to work. Back then, it was a paper-feed pen plotter that was used to plot various measured data online.

The DXY-990 plotter shown below can hold eight pen at the higher left part and moves on an xy-plane using two stepper motors which control a ribbon each. Each initialization process involves finding the lower-left corner which seems to be offset from the x-position of the pen. The plotter can be loaded with a paper size slightly bigger than DIN A3. The paper is held by a controllable static charge (wow! when did this technology disappear?) so that it doesn't move when the pen is hovering or scratching on it.

Why computers suck at maths

admin — Sun, 01 Nov 2009 17:26:41 +0000

Here is a nice article describing the problems that rise due to the methods used in nowadays computers to calculate simple mathematics. Interesting read.

iRobot explores new ways of robotic transition

admin — Mon, 19 Oct 2009 10:43:32 +0000

With the use of mechatronically controllable flexible material, the shape-shifting robot created by iRobot can actively roll around in order to get from one place to another. Interesting and long-overdue transition mode.

More about it.

Multiscale Measurement Systems

admin — Wed, 12 Aug 2009 20:54:15 +0000

Zoom into Human Skinvon Weird_Weird_Science Nice visualization of the use of multiscale measurement systems. Used sensors include a simple video camera, an opto-microscopic camera (maybe a confocal microscope) and i think they had to use an electronic microscope for the last steps. I like how they were able to smooth out the zoom operation accross the [...]

Nice Fourier poem

admin — Thu, 09 Jul 2009 07:56:06 +0000

A poem written in honor of the ever-enlightening Fourier-transform, which is often hated by students, mainly because they don't know what it means.. Here is to the Fourier-transform:

One day in a land far away
Some mathematicians at play
Found a transform of convenient form
The basis of physics today.

Creating Gray-Code sequences using gimp

admin — Mon, 15 Jun 2009 09:00:32 +0000

I needed to implement gray-code sequences for a fringe projection system i'm trying to build. To avoid hard to understand and not really intuitive C-code, i used gimp to produce the projection images. In this article i'm going to document the code used.

3DMagix: Just Blender renamed

admin — Thu, 11 Jun 2009 12:09:14 +0000

Apparently some silly guy is trying to make fast money by selling the open source and free 3D-software package Blender. He's using the name 3DMagix, which is a pretty dumb name. The site doesn't look to reassuring to me, but there are lots of people (some i am ashamed to call 'close relatives') who would gladly fall for this kind of 'best deal' offers. So, be warned: If you want to check out some nice and really(!) free 3d modelling, animation, texturing and video editing software (and yet some), head over to Blender.org and download it for free without having to register or give out your credit card number.. Thanks to Blendernation for the heads-up.

Working bridge on startup for Virtualbox

admin — Sun, 24 May 2009 20:18:32 +0000

I'm experimenting with a server running under virtualbox on my home computer. Here is the script running as /etc/rc.local that sets my bridge up and starts the virtualbox with the name 'seville':

[bash] ifconfig eth0 down ifconfig eth1 down tunctl -u namous -t tap0 brctl addbr br0 brctl addif br0 eth1 brctl addif br0 tap0 ifconfig tap0 0.0.0.0 promisc ifconfig eth1 0.0.0.0 promisc dhclient br0 vboxheadless -s seville & exit 0 [/bash]

Wordpress 2.8 announced and installed

admin — Mon, 18 May 2009 20:39:51 +0000

The Wordpress version running on this blog is now "2.8-beta1-11380". After the first beta has been announced, i switched the svn installation to trunk again (after having it to branches/2.7) and updated the blog.