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Frank Dürr
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SDN-MQ is a powerful and simple-to-use northbound interface for the OpenDaylight SDN controller. Find out how integrating a message-oriented middleware into OpenDaylight can simplify flow programming and allow for decoupling and horizontal scaling of control logic.

#sdn #sdnmq #opendaylight  
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Paper on Automatic Indoor Mapping @ Percom 2014

Patrick and me, we just arrived back from Percom 2014 in Budapest where we presented our work on automatic indoor mapping using crowds of mobile users (I should also mention that this was joint work with many other great colleagues from University of Stuttgart coming from photogrammetry and distributed systems). 

I think, the results are quite impressive, showing that it is indeed possible to use crowds of mobile users to automatically create complete high-quality floor plans, by opportunistically collecting mobility traces and a novel technique using structural knowledge about buildings to fill uncovered "white spaces" and further improve accuracy. 

If you are interested in the details, here are the links to our paper:

  http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-03&mod=0&engl=0&inst=VS

More information can be found on our ComNSense project homepage:

  http://www.comnsense.de/

--Frank
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Very good point Faraz! That's exactly where the structural building information comes into play. We assume we have knowledge about the possible sizes of rooms (encoded into an indoor grammar). Then traces give evidence, which room we actually have by defining constraints on possible room layouts (users cannot walk through walls, ...). This helps us to correct these kinds of errors. 
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SDN Tutorial @ Informatik 2014

If you have missed our tutorials on software-defined networking at DEBS 2013 and Middleware 2013, you have another chance now! We will give an SDN tutorial at Informatik 2014 here in Stuttgart, and would be very happy to welcome everyone interested in this big trend in networking.

#sdn #informatik2014
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Es kann nur einen geben ...

... der Geländewagen des Jahres wird: MB G-Klasse. Jahr kann man gleich mal durch Jahrzehnt ersetzen. "G" wie Gelände. Das sagt ja schon alles. 

Ich danke hiermit demjenigen bei Daimler, der den G davor bewahrt, aus dem Programm genommen zu werden!!! Sollte sich das ändern, starte ich eine Online-Petition zum Schutz des G!

Zu den SUVs fällt mir nichts ein, außer die Frage, welches Plastikteil fällt eigentlich zuerst ab, wenn man damit ins Gelände fährt? Siehe ab 2:40 :)

  Top Gear Magazine Range Rover Evoque Challenge Road Test
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Glasse nicht Gasse. Danke an Google für das selbständige Ersetzen von Worten... mann mann. Ein ordentliches Korrekturprogramm hätte den Gag mit Glasse anders behoben. Hoffen wir mal das G steht nicht für Google :-)
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The University of Nicosia (Cyprus) offers a Master program in digital currency and accepts Bitcoins to pay tuition. I would say that increases credibility! Or would you trust a university teaching computer science without using computers ;)
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Can get Google Glass now ... hm, well, not really :(

I have received a nice email from Google telling me that now I (or better we = our research project at University of Stuttgart) could purchase Google Glass:

"We're seeking new Explorers and we're opening up some spots in the Glass Explorer Program. Any adult in the US can become an Explorer by visiting our site and purchasing Glass ... including you! "

However, obviously I am not an adult in the US (come on Google, you should have known, or at least have an educated guess by looking at my email address or the country field in the registration form). So "including you" should be replaced by "excluding you" ... once again. 

Sad but true ... we could have really used Glass for nice research prototypes. Guess we have to wait for the international version of Glass ...

--Frank

#glass
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A new tutorial on programming software-defined networks with OpenDaylight, this time about reactive flow programming.

--Frank

#opendayligh   #sdn   #xnc  
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Turing Award for Distributed Systems research for Leslie Lamport

And for his famous Paxos paper, he will also receive the Nobel Prize in literature :)

Knowing that Einstein received the Nobel Price for the photoelectric effect rather than the theory of relativity, he could as well have received the Turing Award for TeX ;)
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"Here’s what will change for you, our users: nothing."
--Jan Koum

That's exactly what I feared when I left WhatsApp (and Facebook).

"There's always room for improvement."
--Frank

#whatsapp
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As Daimler aficionado, I am really happy to see the new Mercedes-Benz C Class :) Daimler really understood that it's not enough to build just a nice car. "Nice" is the kiss of death for a permium car. For a premium car, you have to literally see that it is a great car and why it is worth spending so much money. And looking at the interior of the new C Class, you definitely can see that! 

I admit that during the last years, I was not always too excited about every car with a star. But now I am very happy to see that Mercedes is on the right track! Oh, and by the way in the video from CES 2014, you can also see that Mercedes can implement nice gadgets.

 Mercedes-Benz Innovation at 2014 Consumer Electronics Show CES 

But forget about the gadgets! If you like playing with Facebook more than driving your car, you have the wrong car! 
 
Class and style down to the very last detail. A closer look at the C-Class interior design.

[C-Class | Combined fuel consumption: 5.8-4.0 l/100km | CO2 emission: 135-103 g/km | http://mb4.me/EfficiencyStatement]
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The biggest bang for the Watt, or how to make money out of thin air with Bitcoins

Some time ago, I saw a very interesting presentation by Prof. Sebastian Lehnhoff from University of Oldenburg about smart power grids. During his talk, he also mentioned that there are periods at the energy market, when the energy price gets negative -- then you get money for "buying" energy and additionally you get the energy! I will not go into details to explain the reasons but point you to the explanation given at the European Power Exchange website:

http://www.epexspot.com/en/company-info/basics_of_the_power_market/negative_prices

However, negative prices are not just a theoretic concept. It happens in reality. As described in this study:

http://www.ise.fraunhofer.de/de/downloads/pdf-files/aktuelles/kohleverstromung-zu-zeiten-niedriger-boersenstrompreise.pdf

In the first half of 2013, there were 36 h of negative prices where 176 GWh energy were "sold" for minus 12.6 Mio EUR. And with the advent of renewable energy, these periods might further increase. So this is concept number one, how to make money out of thin air.

Then recently I found a second concept to make money by burning energy: Bitcoin mininig. Possibly, everybody has heard about Bitcoins these days, and I think the concept of Bitcoin mining is also already known: You get money for calculating so-called proofs of work based on the calculation of a large number of hash sums. This concept ensures that as long as at least 50 % of the computational power is owned by honest participants, double spending of Bitcoins is avoided -- although this 50 % limit is questioned by this article 

http://hackingdistributed.com/2013/11/04/bitcoin-is-broken/ 

of Cornell researches which I have not read yet; so let's better say a significant portion of the participants should be honest to keep the system consistent. Of course, these calculations don't come for free: You need to invest energy.

It should be obvious that both concepts can be even combined to make the most money: You could mine Bitcoins while the energy price is negative! However, it still might be interesting to know, whether you earn more money just because you burn energy, or because you mine Bitcoins. If more money comes from wasting energy, then you could as well buy some water heaters, because they are much cheaper (reduced CAPEX), without bothering too much about Bitcoins. If on the other hand a significant portion of money comes from Bitcoin mining, it might be even profitable if the energy price is high(er than zero).

The following calculation is not very scientific. In fact, it's not scientific at all, and a "back of the envelop calculation" at best. Still, the comparison might be interesting.

So let's first calculate, how much money you earn per Kilowatt-hour while the spot price is negative based on the numbers from above: 176 GWh energy sold for minus 12.6 Mio EUR (should be plus 12.6 Mio EUR from our point of view ;)  So you receive on average 0.07 EUR/kWh.

Let't see how much money we get per Kilowatt-hour for Bitcoin mining. Today, the most energy efficient way of doing mining is by using ASICs, which are more efficient than FPGAs, and much more efficient than GPUs, and much much more efficient than CPUs. So I took the Monarch ASIC from Butterflylabs as reference, which according to the spec-sheet has a processing speed of 600 GH/s (Giga hashes per second), power consumption of 350 W, and a price of 2196 Dollar (much more expensive than a water heater ;) According to the Bitcoin system, a lucky Bitcoin miner who was the first to calculate the proof of work of a block gets 25 Bitcoins every 10 minutes (of course, this is not always the same miner but usually different ones every 10 minutes ;) 25 Bitcoins are equivalent to about 17500 EUR at the time of writing this post. According to this website 

http://bitcoin.sipa.be/

currently the pool of hardware in the whole Bitcoin system can do about 17500 TH/s. Therefore, using one Monarch ASIC, we should get a fair share of 17500 EUR * (600 GH/s / 17500 TH/s) = 0.60 EUR every 10 min or 3.60 EUR/h spending 0.350 kWh of energy (of course, we only get the money after a longer period of time, if we do not join a mining pool). So we get 10.29 EUR/kWh (using an optimistic calculation without considering additional costs for hardware, cooling, etc.)

So Bitcoin mining brings you the most money per Watt, although you can get some extra money during periods of negative energy prices. 

However, there are some problems of course. First, the reward is halved about every four years making mining less attractive. Second, the computational power of the pool increases -- and it increases fast if you look at these charts

http://bitcoin.sipa.be/

--, which in turn decreases your fair share if you don't invest into new hardware. And of course it remains completely unclear, what a Bitcoin is worth in the future. So a very high risk.

Anyway, investing your energy into Bitcoins to keep the system alive might be more reasonable than heating up some water, so you won't feel guilty because you burned energy for nothing than making money ;)

Just my two Satoshi!

#bitcoin #energy #market 
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Have him in circles
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  • Universität Stuttgart
    Senior Researcher (Postdoc), Lecturer, present
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Computer scientist (currently postdoc at the University of Stuttgart) and photography aficionado.
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Frank Dürr's +1's are the things they like, agree with, or want to recommend.
DriveGreen
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Wie ökologisch-nachhaltig sind Sie wirklich mit Ihrem Auto unterwegs?Die DriveGreen-App bewertet Ihr individuelles KfZ-Mobilitätskonzept anh

UbiComp 2013
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The leading venue for worldwide research in Pervasive and Ubiquitous computing

Panodroid for Android
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Personal Web Page of. Frank Dürr. Panodroid. Home; Scientific Work; Software; Photography; Contact. Back to category Software. Panodroid for

Panodroid - Android Market
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Panodroid for Android is a 3D panorama image viewer for panorama images hosted at Flickr. Panodroid displays 360x180 degree panorama images

Personal Web Page of Frank Dürr
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News. October 17th 2010: Update to Panosalado Viewer available. September 10th 2010: New panorama images of Plochingen available. September

PhotoFlux for Android
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Personal Web Page of. Frank Dürr. PhotoFlux. Home; Scientific Work; Software; Photography; Contact. Back to category Software. PhotoFlux for

Panorama Image Gallery
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Personal Web Page of. Frank Dürr. Panorama Image Gallery. Home; Scientific Work; Software; Photography; Contact. Back to category Photograph

Red Dot Sight as Camera Viewfinder
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Personal Web Page of. Frank Dürr. Red Dot Sight as Camera Viewfinder. Home; Scientific Work; Software; Photography; Contact. Back to categor

Tone Mapping Algorithms—A Subjective Comparison
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Personal Web Page of. Frank Dürr. Comparison of Tone Mapping Algorithms. Home; Scientific Work; Software; Photography; Contact. Back to cate

Panosalado Viewer
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Personal Web Page of. Frank Dürr. Panosalado Viewer. Home; Scientific Work; Software; Photography; Contact. Back to category Software. Panos