DTU stackexchangers

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DTU-associated people on Stackexchange et al. The list is not in anyway complete or well-counted.

Name Reputation
David Kofoed Wind 5524
Allan P. Engsig-Karup 1991
Finn Årup Nielsen 1721
Jóan Petur Petersen 942
Per Kristian Lehre 101
Mark Payne 54

Gone Tumblr

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First my blog was on Posterous, but then they close that site, so I move to WordPress, but have not been satisfied with the editing interface. So now I am moving further on to tumblr:


My elevator talk video

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I was surprised to find that not all know my 225-view famous perhaps semi-humorous elevator talk video. So here it is.

Please note the matched timing of the speech and the elevator. It took me some time to get the match right: Several times up and down the elevator. :-)

Latest form of scam?

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So I got an email from an apparently friendly person asking whether she could translate and use content from our server neuro.imm.dtu.dk “looking forward to hear from me”. I replied yes you can use it under a CC-BY-SA license which she didn’t quite understand.

After a few emails back and forth she ended up thanking me for allowing them to translate www. doflick. com / AboutUs.aspx which I am not at all affiliated with, and then her latest email reads:

“Can I ask you for a favor? Please place a tiny link back to the translation (webhostinggeeks.com/science/berrikuntza-doflick-eu), […]”

No, Jennifer. I will not do that. Neither tiny link nor big, – nor medium for that matter.

I am confused: It sounds – to me – as a new kind of elaborate search engine optimization.

My leg, my leg for 1.9 million kroner?

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Do you want to pay 1.9 million Danish kroner for your leg?

Some days ago I finished reading Danish defense lawyer Bent Nielsen’s book (‘Det er il’godt træls: en forsvarsadvokats dilemma) where he recounts and debates some of his cases. Among the issues he address is compensation to victims of crime. Bent Nielsen writes:

Denmark provides miserable damages on injuries.

Its ridiculous amounts when the limbs, eyesight and hearing and all our vital organs are put in compensatory money terms. And there is even talk about damage that can be measured and assessed. I once asked one of the High Court judges after being annoyed at something he had said: “A personal question, Judge, can I buy your leg for 100’000 DKK?”

As examples he recounts a case where two men raped a women with a knife. Compensation: 40’000 Danish kroner, that is around 5’000 Euros. Bent Nielsen instead suggested 500’000 kroner, — as a beginning. At around the time when Bent Nielsen’s book was published in 2002 the law was changed so the going rate now is 60-70’000 kroner per rape, – still far from Bent Nielsen ten times increase.

Normally the criminal (or the insurance company) should pay the damages. However, if the criminal cannot pay or the victim cannot get money through the insurance, then the Danish state must pay (according to the law). Maybe there’s the rub. For in that pay lies a cost for the taxpayer which apparently is around 100 million kroner for the total of Danish cases per year. (This state compensation is handled thought the Erstatningsnævnet which have further details their homepage)

But why should the Danish state pay for the wrongdoings of a criminal at all? Increase the compensation to the Bent Nielsen levels and let the criminal pay whatever he can, e.g., by working in prison. The state compensation can be (IMHO) ridiculed: Lets say a guy owes money to a gang. The gang kidnaps the man and drives him around for 6 hours in Copenhagen and the surrounding area while threatening him. The gang leaves him physically unharmed, and he seeks damages for 6 hours of kidnapping and gets 20’000 kroner from the Danish state. This is one of the cases from the Erstatningsnævnet’s annual report. Did the guy paid off his debt with the money…?

From my course in law at he Engineer College of Aarhus back in the 1990s I recall a story about a guy using a walkie talkie. He was on the wrong channel and disrupted the communication between a captain of a ship and the marine pilot with the result that the ship crashed into the quay (AFAIR). The guy with the walkie talkie got to pay huge damages. The moral of the story is that your small failures can – in very unfortunate circumstances – result in large expenses to others.

A few days ago a Danish court of appeal settled large damages for the case of the so-called “fodboldtosse” (the football fool). In 2007 during the match between Denmark and Sweden in Copenhagen the drunken fodboldtosse ran into the field and attacked the referee. The European football federation (UEFA) punished the Danish organizers so they had to put the games in smaller stadiums (which meant loos of income) and pay a fine on 281’000 kroner. The court of appeal determined the amount to be around 1.9 million kroner (approx. 240’000 Euro), which is probably fair, – as lawyers also agree. The fodboldtosse has not got that large amount of money and there are no taxpayers to help. A number of people feel pity for the drunkard and started a collection. Presently a pool on Facebook is just over 30’000 kroner, so now they only need the rest 98%.

It is telling to note that for the amount on 1.9 million the fodboldtosse could have raped 29 women and paid full damages. The remarkable discrepancy between criminal damage and the large lawsuit damage was also noted on Facebook by comedian Frank Hvam commenting on the fodboldtosse and a recent nasty criminal case where the damage (state-funded, I suppose) was settled on 150’000 kroner. The particular Facebook post has gained over 17’000 likes, over 4’000 share and over 1’000 comments.

When I was little I actually thought that you would get money from the police if a thief stole from you. Later I found out that this is not the case. If the state is supposed to cover the damages I think it would be interesting to see what would happen if the individual police districts were to pay for damages made by criminals.


(2012-02-21: spelling corrections)

Onsdagslotto – when to play and win the superpulje

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The so-called “superpulje” in “Onsdagslotto” (Viking Lotto) has reached a record breaking amount on 125 millions and with extra so-called jackpots reaches 157 millions. This is around 30 million US Dollars or 22 million Greek Euros (equivalent with 22 million German Euros).

It is dangerous to talk about the statistics of Onsdagslotto as twice our local statistics watchdog Mikkel N. Schmidt has caught researchers giving the wrong odds: The first time blogging Mikkel caught Jørgen Hoffmann-Jørgensen from University of Aarhus giving the wrong odds. The second time Master Schmidt found that University of Copenhagen Professor Mogens Steffensen‘s odds or the Politiken newspaper reporting his odds were wrong.

Fearless of Mikkel I will now attempt my computations (which are probably wrong).

In Onsdagslotto you pick six numbers from 48. The number of different combinations/rows are (48*47*46*45*44*43)/(6*5*4*3*2*1) = nchoosek(48,6) = 12’271’512 = around 12 millions. The so-called superpulje is released if an extra independently picked number (a 7th number) hits one of the six numbers. The probability that the superpulje is released is thus 6/48 = 1/8. It means that on average you need to play nchoosek(48,6)*8 = 98’172’096 = around 100 millions rows before you win the superpulje.

Hoffman gave (48*47*46*45*44*43*42)/(7*6*5*4*3*2*1) = 73’629’072 for the superpulje. This number is correct if you were to hit 7 numbers from the 48. But this is not how the rules are (as far as I understand).

In the report from Professor Mogens Steffensen the newspaper made it sounds as if the value of 98’172’096 was the number of combinations from one coupon. But there are 10 games on each coupon, so the average number of coupons you need to play are nchoosek(48,6)*8/10 = 9’817’209 = around 10 millions, – as Mikkel notes.

Apparently, it costs 4 Danish Kroner (DKK) to play one row/combination/game. To play all combinations will cost you 12271512*4DKK = 49’086’048 DKK = around 50 million DKK. Peter Brodersen noted that as the superpulje was hit this week you could have gain a considerable number of money if you had played all combinations. The bad news for the strategy of playing all rows is, however, as Brodersen also mentions, that you do not know if the seventh number hits the 6 others and you do not know whether you need to share the amount with other players.

On average you need to spend nchoosek(48,6)*8*4DKK = around 400 million
DKK playing all combinations before you hit the superpulje. It seems to be more difficult to compute the probability that you have to share the amount from the superpulje. During these times with a large superpulje Danes are playing for around 65 to 82 millions DDK each round, meaning around 20 million combinations are played in Denmark and that on average each combination is played around one or two times (82000000/4/nchoosek(48,6)). However, the superpulje is shared with other countries in the Nordic region. One blogger notes that we are 33.4 millions in the region. If the people in the other countries play at the same rate as Danes, does that means that a superpulje winner has to share it with 9 other people on average? (33.4/5.5*82000000/4/nchoosek(48,6)=10.145). I am not sure I understand the rules correctly… Because last week when the superpulje could have been released no player hit the six correct numbers among the 48. If Danes are alone to play the probability of no-one not hitting the six correct is around 25% (1-1/nchoosek(48,6))^(65000000/4). Whereas if we use the Danish playing rate on the entire Nordic region population we get around 0.0003 (1-1/nchoosek(48,6))^(33.4/5.5*65000000/4). So either I am computing this wrong or I misunderstand the rules or the playing rate is quite lower in the other countries, – or it was a very unusual drawing. Yet another explanation is that some people play systematically. It has been reported that one particular combination was played 1’600 times. If you win the superpulje alone you will apparently also receive the secondary prizes, – if I understand correctly. That amount I read on one news site (Avisen.dk) to be around 10 million DKK.

The rate of which other people play, their rate of systematic playing and the secondary prizes make the computation of when it is an advantage to play difficult. If you disregard the secondary prizes it seems that the superpulje needs to grow to at least 400 million DKK before it is an advantage to play “against” it. It needs to grow further if you count in the other players that might hit your six numbers.

One popup page on the Danish lottery website states that the average payback percentage is 45%. It is unclear for me how the payback is distributed between the different prizes. If we assume that 40% is used for the secondary prizes it means that if we play for 300 million DKK we will on average get 120 million DKK back from the secondary prizes, the rest, 180 million DKK is at stake for winning the carried-over superpuljen (if my understanding is correct). Given that the amount accumulated in the superpulje is now going towards the 180 million it seems that it is almost an advantage for me to play, – provided that the rest of you do not play so I have to share the prize.


(Correction: Typo 17:39)

Telenor driftstatus unavailable

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My Internet usually works ok, but two days ago I was hit by periodic dropouts on my Telenor broadband Internet. The “Internet” LED on the ZyXEL P-660R-D1 DSL modem at my place was unlit for several minutes many times during the evening and during these periods I was unable to get further than However, as the error was periodic I could occasionally get on the Internet and search for what was wrong. In this process I found the information on the status of Telenor’s Internet insufficient for me.

Telenor customer service is not available during evenings through telephone. You can report an error via a web form, but I didn’t manage to discover that page. I rebooted the modem several times by switching off the device. One page states that you should wait 20 seconds, – which I might not have done: It is possible that the device in the other end of the cable needs not just a reboot but several seconds to detect and correct the problem. I have entered my email so Telenor can send me emails about interruptions in the operational status of the Internet, but I have never seen an email from them. I could not get a clue from the Telenor status page. My search on Twitter on “telenor” got noone reporting problems except myself.

Next day the unstability was over, but I called Telenor to get a postmortem debriefing. After waiting perhaps 7 minutes to get to a human the person at the other end told me that there had been a problem. He got my email so he could write to me with more information, but I have received no email so far. The present information on the Telenor status page gives me no indication of the problem, – the closest message is from 14. december 2011 14:15:57 which gives information about work on their hosting platform. At one point this Telenor status page displayed rather funnily the message “Service unavailable” (remember Hamlet: Something is rotten in the state of the state of Denmark).

During the exponential growth of Wikipedia and Twitter you would often run into capacity problems with these services. For Twitter you would have the famous failwhale that gave a clear indication and understanding that there was a problem. You could use http://www.downforeveryoneorjustme.com to check the availability of webservices. To me the dropouts that from time to time (sort of reasonably rarely) occure in my broadband Internet access are enigmas. One other Telenor customer has reported that the broadband problems might be due to a so-called lorte-central. Given no other information I have to accept that explanation.