Testing file-size limits

6th March 2015

For testing purposes you may want to provoke a file-size error. Here are the steps. Open a new bash/xterm. Set a file-size limit with ulimit, then write a file with dd. ulimit -f 1 dd bs=1 iflag=count_bytes count=5000 if=/dev/zero of=yourFile The resulting error is File size limit exceeded (core…

Average daily commuting time in Europe and the U.S.

3rd March 2015

Below chart is taken from Stress That Doesn't Pay: The Commuting Paradox, August 2004, pageĀ 30. The data is per 2000/2001. The above document links these numbers with reported satisfaction with life -- longer commuting times means less happiness. Numbers change over time. Five year later the U.S.…

Using GnuPG for encryption and decryption

28th February 2015

On Ubuntu install with: apt-get install gnupg First generate private and public key: gpg --gen-key Generating this key can take some time, because it needs enough randomness. Store your public key in a file: gpg -a --export Although it is not necessary to store this public key, you usually will…

WordPress.com News and Numbers: Year 2014 in Review

13th February 2015

Im(Press)ive! Your Year in Review published some usage statistics for the year 2014, which are quite astonishing: 18,300,771 new blogs 555,782,547 new posts 24.5 TB/h (Terabyte per hour) Compare this with statistics from year 2013: 13,704,819 new blogs 489,281,136 new posts 667,675,929…

Downloading Binary Data, for example Boost C++ Library

12th February 2015

Downloading the Boost C++ library is occasionally hindered by various company policies. boost_1_57_0.7z.rc4.b64 is Boost version 1.57.0 (MD5 is 17c98dd78d6180f553fbefe5a0f57d12) in the following format: compressed with 7z, size 55 MB encrypted with RC4, password "boost", size doesn't…

Announcement: 11th International Conference on Parallel Programming and Applied Mathematics

7th February 2015

The conference will start in September 6-9, 2015, Krakow, Poland. Parallel Programming and Applied Mathematics, PPAM for short, is a biennial conference started in 1994, with the proceedings published by Springer in the Lecture Notes in Computer Sciences series, see PPAM (dead link). It is…

Two Free Invites for the OnePlus One

22nd January 2015

Below are two invites for the OnePlus One smartphone. These two invites expire in less than 12 hours. Don't click on the invites if you don't want to actually purchase the…

Setting up SLURM on Multiple Machines

17th January 2015

SLURM is a job-scheduler for Linux. It is most useful if you have a cluster of computers. But if you only have two or three computers it can be put to good use. SLURM is an acronym for Simple Linux Utility for Resource Management. SLURM is used by Sunway TaihuLight with 10,649,600 computing cores,…

Migrating from delicious.com to WordPress

5th January 2015

I have been a loyal user of del.icio.us since 2006. I have written on this in my post Saving URLs in del.icio.us Still Troublesome. But now enough is enough. Here is a list of annoyances: You can neither export nor import your data anymore. The service is generally slow, i.e., it takes a lot of…

Three Free Invites For the OnePlus One

30th December 2014

I have written a review on the OnePlus One smartphone. I have three more invites for the OnePlus One smartphone. Below are the codes. Use them according "first come, first served". Invite 1 with code GLK0-ZEFI-BW0A-MYZG has been claimed and used. Invite 2 with code GLV4-U7PE-V1AL-YJZN was…

2014 in review - report generated by WordPress

30th December 2014

The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog. Here is an excerpt: The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 13,000 times in 2014. If it were a concert at Sydney Opera House, it would take about 5 sold-out…

Hard-Disk and USB Drive Speed Comparisons

28th December 2014

Continuing the post Harddisk Drive Speed in MB/s, here are some benchmarks for consumer grade hard disks, USB thumb drives, and solid state drives (SSD). A 64 GB SanDisk USB 3.0 thumb drive: This USB drive has only half of the speed of the USB drive given below. A 32 GB JetFlash Transcend USB 3.0…

Statistics of this Blog: Crossed 15.000 Views

27th December 2014

This blog was viewed more than 15.000 times. As in this post, here are the numbers: The averages per day are: Comparing last year and this year: Visits went up by a factor of seven. The development of visits is as below: Google is the top most important referrer by far: Most visited posts in…

Thank You Hungary

24th November 2014

In the year 1989 people from Soviet occupied eastern Germany could flee to West-Germany via Hungary, see German reunification in Wikipedia. Hungary had opened the border to Austria. The German embassy in Hungary initiated a public advertising campaign thanking Hungaria, see Deutsche Botschaft…

I have OnePlus invites to give away

19th November 2014

I can share 6 OnePlus invites for the next 5 days, i.e., up to Sunday, 23-Nov-2014. Device in question: One - 64 GB Sandstone Black. If anyone is interested please comment below with your e-mail address and I will hand out the invite. I will not publish or use your e-mail address for anything…

Short Review on Film Citizenfour

9th November 2014

Yesterday I went to the movie with my family and watched Laura Poitras's film Citizenfour. The movie in Frankfurt was completely sold out, many prospects had to be sent home, because there were no more seats available. I just got a ticket because I had a high number on the waiting list. I am…

Effect of Optimizer in gcc on Intel/AMD and Power8

27th October 2014

What effect can the optimizer have for gcc? On Intel/AMD I ran my intpoly program (with -n0) once with and once without optimizer. It showed a speed-up of aboutĀ 3. no optimizer: 7.84s -O3: 2.25s gcc for Intel/AMD is version 4.8.2. On Power8 I again ran intpoly (with -n0). The factor is more…

WordPress/Automattic: Monthly Unique Visits and Employees, Part 2

24th October 2014

Last year I copied the employee and visit count of WordPress and posted this here. Now one year later the situation is still similar. The data is again from Work With Us. Company NameMonthly Uniques…

Review of the OnePlus One Smartphone

21st October 2014

End of August I bought the OnePlus One smartphone, henceforth called OnePlus. Previously I owned a Google Nexus 4 smartphone. My initial motive for a new smartphone was to have more storage in my phone. As I use my phone as a camera and do no longer use a "real" camera, lots of pictures…

Advances in Automotive Technology

20th September 2014

Since a couple of decades people drive cars, motorcycles and trucks which pretty much look and work the same as a couple of decades ago. I.e., cars are made of steel, use a fuel powered motor, have 4 seats, etc. Although there are clearly advances in the area, like fuel consumption, electronic…