Syncing with J-Pilot via Bluetooth

14th April 2014

Probably I am a little bit old-fashioned, but I still use J-Pilot on my PC and my Tungsten T5 and sync them. It mostly serves as a kind of backup so I have my valuable address and datebook data on separate media. So in case my PC gets inaccessible then I have my data on this device at least. These…

Youtube video to mp3

1st April 2014

Assume you want to download just the music of below video on Youtube, so you can listen to the music on your phone, while you are on the road. Here are the necessary steps on the command line: youtube-dl www.youtube.com/watch?v=aHjpOzsQ9YI mv Crystallize\ -\ Lindsey\ Stirling\ \(Dubstep\ Violin\…

Enabling Power-Aware Applications on Linux Using Cyrogenic Module

23rd March 2014

A post in Phoronix: "Cryogenic" Linux Kernel Drops Power Use shed light on a Linux kernel module improving power consumption. This module was written as part of a master thesis in computer science at TUM (Technical University of Munich) by Alejandra Morales Ruiz. The thesis is well…

Calculating number of seats in parliament using d'Hondt's method

24th February 2014

Wikipedia contains an article on d'Hondt's method for calculating the number of seats given the number of votes for each party. I wrote a short Perl program for its calculation including the case when d'Hondt's method by its design leads to drawing the lots. Its input contains a list of party names…

[STORY] Lufthansa Airbus A380 Landing in San Francisco

16th February 2014

Very nice article on http://pilotseye.tv/ Added on 20-Mar-2014: Original blog post, which was reblogged here, apparently has been deleted. So I put a video from PilotsEYE here: -- -- -- Quote -- -- -- I have always been interested in flying and aviation. I recently found an…

Statistics of this Blog: 2.600 Views, 78 Countries, 20 Comments

11th February 2014

In two previous posts My Blog Statistics by Country and Statistics of this Blog: 1.000 Views, 60 Countries, 10 Likes I showed the statistics of this blog in September and October last year. The last few weeks I was quite heavily loaded with work, so I couldn't announce that I broke the 2.000…

Scheduling Cron Jobs on Business Days

9th February 2014

I found a marvelous way to run jobs on certain business days via cron. The solution was depicted in Scheduling Cron Jobs on Business Days and it was written by a user named rdcwayx. The idea is to use the output of cal and some Awk or Perl string-trickery. The output of cal looks like this February…

Cisco 2014 Annual Security Report: Java continues to be most vulnerable of all web exploits

19th January 2014

Cisco provides a report on computer security which contains a number of key findings: Java comprises 91% of all web exploits. 99% of mobile malware targets Android. Java is the exploit that criminals choose first, since it delivers the best return on investment. In the aftermath of the Boston…

Youtube 500 Internal Server Error

17th January 2014

Today I noticed the following error on Youtube, which seems to be quite rare. Maybe some trained monkey comes by and can make use of below gibberish. 500 Internal Server Error Sorry, something went wrong.A team of highly trained monkeys has been dispatched to deal with this situation. If you see…

Ignoring Security Certificate Errors in Google Chrome

15th January 2014

Unfortunately Google gets quite draconian to users: When using Google Chrome to surf a web page with a certificate problem, you simply cannot view the web-site. There is no dialog, where you can say: It's o.k., I accept the risk. This behaviour occurs at least with versions 31.0.1650.63 and…

Changing euid (effective user ID)

13th January 2014

Sometimes you have to create applications in an environment where you are not able to su to root, or use sudo. Nevertheless you are working with two or more user IDs to make your application work. For example, your business application is running under user ID 1555 (let's call this user u1555),…

Working with System V IPC queues in Perl and PHP

10th January 2014

In continuation of Working with System V IPC queues a month ago this post will show how to access IPC queues with Perl and PHP. A typical scenario is that a web application wants an external application to process data coming from the web application. In that scenario a lot of messages/tasks from…

Plotting Power Consumption of my Desktop PC

7th January 2014

I own a desktop PC with an AMD octacore FX 8120 and a NVidia GTX 560 graphic card running GPUGrid. What is the power consumption in Watts over time? I ran ( while true; do powerconsum ; sleep 2; done ) & with below script powerconsum reading data from sensors: #!/usr/bin/perl -W use strict; my…

Effort Estimation Using Learning Curves

2nd January 2014

A couple of times I had to conduct effort estimations which contained a number of repetitive tasks. The question was, how long does it take to finish all these tasks. For example, I had to provide estimates how many days it would cost to program an interface between one system interfacing to a…

Performance of Dalvik versus native C compilation

30th December 2013

Android application programs are usually written in the Java programming language. Java source code is compiled to bytecode, which is then interpreted by the Java virtual machine. Current virtual machines (VM for short) use two tricks to improve performance: compile bytecode to machine code during…

What is generally better: 64-bit or 32-bit?

21st December 2013

I was just asked this question and referred to Phoronix: Ubuntu 12.04 LTS: 32-bit vs. 64-bit Performance. Phoronix is this excellent web-site run by Michael Larabel. Below is a chart from 2012. Not all charts look this astonishing! This was also true in 2006, see below compilation times. So the…

Linux commands: expect and kibitz

12th December 2013

Occasionally I teach customers and colleagues how to use some aspects of Linux, or how to use and administrate newly developed software on Linux. I regularly use either VNC or kibitz for this. While VNC is somewhat known to many people, kibitz seems to be like a hidden germ, unbeknownst to…

Wikipedia Infrastructure as of 2013

9th December 2013

Some facts on Wikipedia: Wikipedia uses round about 1,200 servers, see Tactical Monitoring Overview. These servers are located in Ashburn (Virginia), Tampa (Florida), San Francisco, and Amsterdam, see servers. Wikipedia has about 4.5 million pages, see statistics. Wikipedia uses Ubuntu exclusively…

Surfing the internet with 100 MBit/s

8th December 2013

This week I upgraded again, this time from 50 MBit/s to 100 MBit/s. My internet service provider is Unitymedia with whom I had positive experience since 2009, see Unitymedia experience. They phoned me mid of November and asked whether I would be interested in upgrading from 50 to 100, it would cost…

Astronomy at Home – Brian Koberlein

3rd December 2013

Great article about Einstein@Home by Brian Koberlein: Astronomy at Home – Brian Koberlein. This is interesting in particular: The team used the distributed computing network to analyze x-ray data from the Fermi gamma ray telescope. From this they found four new gamma ray pulsars. Most gamma ray…

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