Headers #9

Headers #9

View from the Floor 17 restaurant on top of the Ramada Hotel in Amsterdam
Headers #9
View from the top floor of the Apollo Ramada Hotel in Amsterdam, showing the bar reflecting in the window
View from the top floor of the Apollo Ramada Hotel in Amsterdam, showing the bar reflecting in the window

Foto: Krijn Soeteman
Date: November 3, 2014
Camera: Canon 6D, EF 24-105mm F/4.0

I used this header for the site for approximately six months, until from November 2014 until April 2015.

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Steam & old Ati (AMD) video cards

Steam & old Ati (AMD) video cards

I dare not say if this fix goes for all older Ati / AMD video cards, but it has helped me a few times now. Because I always forget where I found the answer, I post this to my ‘how did it I fix this again‘ blog-part.

It happened a after upgrading to Ubuntu 14.10 (open source drivers worked fine for games like TF2, Civ V, etc):

OpenGL GLX context is not using direct rendering, which may cause performance problems

Apparently there are some issues with some 32 bit libraries which are shipped with Steam, after which it doesn’t use the systems own libraries any more (some websites state that you should first check if:

glxinfo | grep render

shows the system shows something like:

direct rendering: Yes
GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer,
GLX_MESA_multithread_makecurrent, GLX_MESA_query_renderer,
OpenGL renderer string: Gallium 0.4 on AMD RV770
GL_MESA_texture_signed_rgba, GL_NV_conditional_render, GL_NV_depth_clamp,
GL_NV_blend_square, GL_NV_conditional_render, GL_NV_depth_clamp,
GL_OES_fbo_render_mipmap, GL_OES_get_program_binary, GL_OES_mapbuffer,

Most websites will tell you to remove the following libraries:


The location of the libraries may vary. In my case it’s located under:

That was it.

Facebook: stats on positive and negative posts

Facebook: stats on positive and negative posts

Last Friday (June 27) I noticed a post on Scoop.it by the Dutch TV programme ‘Tegenlicht’. The headline read “Facebook tinkered with users’ feeds for a massive psychology experiment”. Maybe nice to use for a science section of a large Dutch news website. Research is research.

Quickly I skimmed the article on Avclub.com where scoop.it pointed to. Maybe interesting. Maybe not.

Click. The article itself on PNAS. I am not a statistician, but I learned when P < 0.05 than it is statistically significant.*

Scrolling through the article, I see some significant values, but the conclusion reads:

“Although these data provide, to our knowledge, some of the first experimental evidence to support the controversial claims that emotions can spread throughout a network, the effect sizes from the manipulations are small (as small as d = 0.001). These effects nonetheless matter given that the manipulation of the independent variable (presence of emotion in the News Feed) was minimal whereas the dependent variable (people’s emotional expressions) is difficult to influence given the range of daily experiences that influence mood (10). More importantly, given the massive scale of social networks such as Facebook, even small effects can have large aggregated consequences (14, 15): For example, the well-documented connection between emotions and physical well-being suggests the importance of these findings for public health. Online messages influence our experience of emotions, which may affect a variety of offline behaviors. And after all, an effect size of d = 0.001 at Facebook’s scale is not negligible: In early 2013, this would have corresponded to hundreds of thousands of emotion expressions in status updates per day.”

And, even more important in my case, the publication date:

Published online before print June 2, 2014, doi:10.1073/pnas.1320040111

PNAS June 17, 2014 vol. 111 no. 248788-8790

This means it’s been roaming on the Internet since the second of June. Ah well, let’s just skip it, I probably just missed it.

Not. Everybody missed it. And in my humble opinion, it shouldn’t have caused the amount of attention it received since this weekend. It’s interesting, seeing how things work behind the scenes of one of the largest empires Earth has ever seen, but this is just a glimpse and a tiny one.

Why is the world so surprised? It makes no sense at all. It would be surprising if companies which use data and can manipulate it, would not use it, for better or worse.

In this case its results were published. Openly.

Open Access Logo

The question which should be addressed is the following: why is it not mandatory that companies which aren’t ‘companies’ in the old sense of the word, because they serve the world in a way public institutions would, have to list their experiments openly. All experiments. Just like universities and other knowledge institutions (should) do.

Open Access.

*or at least should be, considering all variables are ok, etc. etc.

From Volkskrantgebouw to Volkshotel

From Volkskrantgebouw to Volkshotel

The Volkshotel in the former building of the Volkskrant, still one of the largest newspapers in The Netherlands, transformed during the past year (and the years before that) into an almost new building.

I’ve been experimenting with many different (old) camera’s the past few years. It turned out I took quite a few pictures before, during and (almost) after the make over of the once modern building since I became a member of Bureau Wibautin the Broedplaats** in the VK-building.

Used cameras: Nexus 4, Polaroid (SX-70 and 600), Kodak Brownie model 2, Agfa Rekord II, Venaret

There’s a big disadvantage using a scanner for Polaroids: the tiny layer of plastic shielding the picture from the outside world is thick enough to make the picture look out of focus or just a bit unsharp..

* Bureau Wibaut, a collective of journalists and other media-producing people
** Broedplaats: artist run initiative, a place where rents are relatively low and creativity is high

HowTo: walk or cycle in Amsterdam*, a tourist guide

HowTo: walk or cycle in Amsterdam*, a tourist guide

The rules of thumb are pretty simple:
  • If you want to cross a street, start walking, but do not change speed or direction. The Dutch cyclist will always try not to hit to avoid you. The cyclist cannot avoid you when you stop at once in the middle of the street because you got scared. Now the trajectory which was formed beforehand in the cyclist’s brain, is wrong and the cyclist may hit you after all.
  • If you look up to admire the beauty of the canal houses, do not fall of the pavement (many do, true!).
  • Do not walk on the road, this is the part of the street which usually contains Dutch clinkers in older cities, including motor traffic (a few cars, a lorry here and there, some scooters and cyclists)
  • You’re a tourist. You know nothing of the Dutch unwritten rules of cycling. Don’t try to act like your Dutch, which means: when Dutchies cycle in the opposite direction on a cycling path (which is not allowed) they do it because they can. When you try to cycle in the opposite direction, you usually don’t do it the right way. And explaining ‘the right way’ is just not possible.
  • Cycling on the pavement is often done by Dutchies, but – apart from the fact that it’s pretty annoying – this is not allowed either. You’ll never learn to do it the ‘right’ way (personally I dislike pavement-bikers very much, unless I do it myself)
  • If you rented an airbnb-like place or stay at a friends house and you’re allowed to use the beaten up Dutch bikes, please add a red flag or something telling Dutch road users you’re a tourist. Remember, you’re in disguise now. Rental bikes say: this is someone who probably hardly ever cycles. Keep distance, maybe ring your bell.
  • You should Not ring the bell. It’s for warning signals only, not a toy (which means: when you’re in a scary situation, ring it!)
From left to middle: pannier, front racks, front basket, child seat,
From left to middle: pannier, front racks, front basket, child seat,

Well, that was quite a list. How to lock your bike and other stuff will probably be explained by your bike rental shop.

Why those ‘rules’? It’s fairly simple. When I cycle through the stunningly beautiful city centre of Amsterdam I cycle pretty fast. I can’t help it. My daily regular cycling schedule to and from the office totals at least 11 kilometres**. Any other one way cycling trip usually adds about 5 km to that amount (so if I go and have a drink in the city, I’ve cycled about 21 km that day). Not only when the Sun is shining or when there is a pretty strong breeze. No, everyday. Sun, rain, snow, cold, warm, dark, light, dusk or dawn. It doesn’t make a difference.

But then, always around: tourists. During the holiday season they are as ubiquitous as the bikes. Hopefully this blog helped you understand how the local cyclist feels and thinks and keep you out of trouble!

Have a pleasant stay!

* Or any other city with many cyclists
** Miles, miles. Please! The US, Birma and Libya use the Imperial System. The rest uses SI (France: Système international d’unités) or International System of Units. OK, one time and one only: 11 km = 6.835 miles.


rkhunter tutorial

rkhunter tutorial

Just as a reminder for myself (mainly for when I receive a warning by email and don’t remember some of the CLI commands ;-) )

This website DigitalOcean has a very well written, clear tutorial:

“How To Use RKHunter to Guard Against Rootkits on an Ubuntu VPS”
Exposing any computer to the internet is in some ways risky. There are many ways that your server can be compromised or attacked by remote systems and malicious software, and it is an ongoing and proactive process to defend yourself against potential threats.
One potential concern is rootkits. Rootkits are software secretly installed by a malicious intruder to allow that user continued access to the server once security is breached. This is an extremely dangerous problem, because even after the entry vector that the user originally used to gain access is fixed, they can continue to enter the server using the rootkit they installed.
One tool that can help you protect your system from these kinds of problems isrkhunter. This software checks your system against a database of known rootkits. Additionally, it can check other system files to make sure they are in line with expected properties and values.
In this guide, we will install and configure rkhunter to protect our Ubuntu 12.04 VPS.
Continue reading on DigitalOcean

It says Ubuntu 12.04, but I just used it on 14.04. It’s not really an application type to change quickly.

There’s one thing I would add for those who’ve never set up a cronjob using the crontab command. It saves as a temp. file, but will work.

Amsterdam Waterfront

Amsterdam Waterfront

Amsterdam waterfront seen from the North. Including remnants from the times when this part of the city still had a wharf…
Amsterdam NDSM-werf: Brooklyn Hotel

Amsterdam NDSM-werf: Brooklyn Hotel

Nicely done, this elevated ‘shed’!

Brooklyn Hotel @ NDSM wharf in Amsterdam
Old video games: Zaxxon (Sega 1982)

Old video games: Zaxxon (Sega 1982)

This commercial aired in 1982 for Zaxxon, a Sega game.

“A true feel of action in three dimensions!”

I uncovered this video a few years ago on an old U-matic tape in possession of the Computer Museum of the University of Amsterdam.

While cleaning up my computer(s) and my on-line presence, you sometimes discover old gems :-)

Check out the flat land: the Flevopolder

Check out the flat land: the Flevopolder


The Netherlands are flat. Very flat. That flatness is one of the things to experience when you go there. Yes, you’ll see a glimpse when you arrive at Schiphol Airport (AMS) but no, that’s not what it really looks like. Yes, there are regular daily guided tours to the oldest pieces of reclaimed land called polders  just north of Amsterdam, which are very pretty. Beautiful old wooden windmills. Some old steam driven pumping stations and meandering ditches and canals.

Now come and experience flat. The largest polder ever created in this low country is the Flevopolder. It measures 970 square kilometres, divided in two parts. And that’s exactly where you should go: the dike which divides this huge polder in two.

First of all, it’s close to Amsterdam. For most visitors to this small country it would even be close to Maastricht, which is probably the furtherest you can be from this polder. One of the advantages is you can get a marvellous view of the polder by sitting on the train. Just go to Amsterdam Central Station and jump on the direct train to Lelystad. The ride takes only about 45 minutes.

The city of Lelystad was founded in 1967 and was named after the man who engineered the Afsluitdijk, making the reclamation possible in the first place. As a city it is not a very interesting spot (yet?), but when you’re into modern architecture or want to see a replica of a 1628 trading vessel used by the Dutch East India Company it’s worth leaving the Lelystad train station.

Although the train ride is rather beautiful, you may want to rent a car or maybe even a car with a driver (as driving can be an unpleasant experience in Amsterdam when you’re not used to bicycles*). The A1 and A6 motorways (free of bicycles) take you to the polder within twenty minutes. After a while, leave the motorway, get out of the car and look around. You won’t get lost. The total round trip from Amsterdam centre to the centre of Flevoland (the polder’s real name) including some sight seeing, is about 120 kilometres.

But, first things first. When entering the polder, you’ll pass a city called Almere. Its first buildings weren’t erected until early 1976. The city is quite large, according to Dutch standards, but has hardly any cultural hotspots. It has quite an interesting infrastructure because of its separate infrastructure for bikes, cars and buses.

After the last bits of Almere, you’ll pass a few concrete elephants and a bridge. After that, a vast canvas consisting of agricultural land, unfolds. Roads traverse in straight lines through the fields. Here and there a farm and windmills (the modern, electricity generating ones).

As stated before, the polder is divided in two parts: the eastern and the southern part. The dike dividing the two parts is practically in the middle with the motorway running over it.

Coordinaten van Tong van Lucifer: 52.44150000 N - 5.44116667 E
The ‘Tong van Lucifer’, artist: Rudie van de Wint

On this dike you’ll see a piece of art called the ‘Tongue of Lucifer’ which makes an excellent side trip. Just after you spotted the artwork on the dike, there is an exit going right to Lelystad. Get off there. At the end of the exit lane, go right again and take the second to the right (yes, you’re driving back south west after going north east for about twenty minutes). This should be the Meerkoetenweg. At the end of the road you can’t do much more but park the car, get out of the vehicle and walk al the way to the Tongue. Impossible to miss (except for when all the copper would be stolen again, this happened a few years ago). Before you ascent the dike, realise you’ve been driving and now walking on an old sea floor! There used to be between 2,4 and 3 metres of water above your head.

After walking on the dike for a while and when visibility is good, the flat, engineered land will get to you. This asks for more. Jump back in the car, and take the first road to the right, direction N706. At the N706, direction Amsterdam, take another right after about five minutes on the Reigerweg, direction Oostvaardersplassen. The Oostvaardersplassen are an example of what happens to new land when you don’t touch it for a few decades. Dutch people call it ‘wilderness’. You can’t enter the ‘wilderness’, but there are some nice lookouts on the outskirts. A particular nice one sits in the corner of the Reigerweg and Praamweg. Bring binoculars if you can.

Just follow the road. After a few corners, you’ll be on the southern tip of Lelystad. From there you drive back all along the dike separating the IJsselmeer from the Oostvaardersplassen. Viewpoints all over the place.

Before you know it, you’ll be back in Amsterdam but with a different view of the Netherlands and its countryside.

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* Dutch people on bicycles are close to impossible. If you hit one with a car, the car (driver) is always guilty (with a few exceptions).