So it's a pleasure for me to welcome Susanne Albers from Technical University of Munich

for her presentation on energy efficient algorithms.

Susanne Albers has been here since 2013 at TU Munich before she was at Humboldt University

in Berlin before she was at the University of Freiburg before she was a professor at

the University of Dortmund, studied a PhD in South Rican, was at the Max Planck Institute

in South Rican, is a GE fellow, received the Leibniz Prize and so on and so on.

So she is very well known in the area of algorithms engineering, complexity aspects, more the

say the theoretical aspects of informatics but not only pure theory, she also always

tries to move her achievements to practice to real algorithms running on machines and

that's why I welcome again Susanne for her presentation on energy efficiency aspects

of those algorithms which is also an important aspect of the second phase of our SFB.

Susanne.

Okay, thank you very much for the kind introduction.

First of all I would like to thank Wolfgang Schröder-Freicher and also Jürgen Teich for

inviting me and hosting me.

It's a great pleasure to give a presentation here as part of the Research Centre on Invasive

Computing.

My talk this morning is entitled Energy Efficient Algorithms.

It's a topic that has received quite some research interest in the algorithms community

lately.

It's also a topic that I have been working on for a while, for a couple of years.

So in this talk I would like to present a short survey, a tutorial on the state of the

art and at the same time I would like to present some research results of mine perhaps at the

high level because it's mathematically oriented with proofs and mathematical analysis and

I will try to keep this at a minimum but perhaps show you some short proofs to give you an

idea what this type of research is about.

So let me start with some motivation.

You'll probably agree that energy has become scarce and expensive resources also holds

true for many computing environments in terms of energy availability or actually limited

energy availability.

Power dissipation is certainly critical in portable battery operated devices.

Each of us has experienced the event that the battery of our laptop or mobile phone

runs empty.

The issue is even more critical in sensor networks where the charging of batteries is

difficult or impossible.

Power dissipation is also critical in terms of cost.

The electricity cost impose a substantial strain on the budget of computing and data

centers.

For instance, Google spends about $1 billion per year on electricity which is significant

in terms of electricity cost.

At Google I can also mention a couple of famous quotes in the New York Times.

Eric Schmidt, the former chief executive officer at Google said what matters most at Google

is not speed but power, low power because data centers can consume as much electricity

as a city.

This quote is already 10 years old or 12 years old in a New York Times article but it still

holds true because in a more recent article, again New York Times 2011, Google disclosed

that it uses enough electricity to power more than 200,000 homes.

More generally, the availability of low cost power is a major criterion to build data centers

not only for Google but also for other major companies, Facebook and Apple.

And last but not least, as you know, high energy consumption causes thermal problems.