Robustness

"A lady said, 'What's your solution?'
I said, 'There are no solutions. There are only trade-offs.'
She said, 'The people demand solutions!'
- Thomas Sowell

Internet download speeds could be improved dramatically by mimicking Darwin's evolution to "breed" the best networking strategies, say computer scientists.

Transferring popular data across the internet repeatedly can be inefficient and costly, so networking companies have developed ways of temporarily storing, or "caching", data at different locations to reduce costs and increase download speeds.

But figuring out where to store data and for how long is a complex problem. One solution might be to have caches "talk" to each other repeatedly, but this is inefficient as it takes up a lot of bandwidth.

To tackle the challenge, Pablo Funes of US company Icosystem and Jürgen Branke and Frederik Theil of the University of Karlsruhe in Germany used "genetic algorithms", which mimic Darwinian evolution, to develop strategies for internet servers to use when caching data. Using a simulation they were able to improve download speeds over existing caching schemes.

In finding an answer to “perhaps the greatest unsolved ecological riddle,” evolutionists propose that diversity is a testament to there being more than one way to make a living.

The riddle: Why are some habitats loaded with many more species than others?

The answer: Nature and evolution respect that there’s more than one way of doing things.

“What we’ve learned,” said Michigan State University scientist Charles Ofria, “is that if there isn’t just one way to succeed, you’ll see diversity.”

In an article published in the July 2 issue of Science, an interdisciplinary team of scientists at MSU, the California Institute of Technology and Keck Graduate Institute (KGI), with the help of powerful computers, has used a kind of artificial life, or ALife, to gain insight into questions of evolution.

Scale-free networks are everywhere. The can be seen in airline traffic routes, connections between actors in Hollywood, weblog links, sexual relationships, and terrorist networks. So what exactly is a scale-free network? A scale-free network is one that obeys a power law distribution in the number of connections between nodes on the network. Some few nodes exhibit extremely high connectivity (essentially scale-free) while the vast majority are relatively poorly connected. The reason that scale-free networks emerge, as opposed to evenly distributed random networks, is due to these factors:

* Rapid growth confers preference to early entrants. The longer a node has been in place the greater the number of links to it. First mover advantage is very important.
* In an environment of too much information people link to nodes that are easier to find. This preferential linking reinforces itself by making the easier to find nodes even more easy to find.
* The greater the capacity of the hub (bandwidth, work ethic, etc.) the faster its growth.

The Strength and Weaknesses of Scale-Free Networks
The proliferation of scale-free networks and our increasing dependence on them (particularly given their prevalence in energy, transportation, and communications systems) begs the question: how reliable are these networks?

Network-centric warfare demands robust systems that can respond automatically and dynamically to both accidental and deliberate faults. Adaptation of fault-tolerant computing techniques has made computing and information systems intrusion-tolerant and much more survivable during cyber attacks, but even with these advancements, a system will inevitably exhaust all resources in the face of a sustained attack by a determined cyber adversary. Computing systems and information systems also have a tendency to become more fragile and susceptible to accidental faults and errors over time if manually applied maintenance or refresh routines are not administered regularly. The Self-Regenerative Systems (SRS) program seeks to address these deficiencies by creating a new generation of security and survivability technologies. These "fourth-generation" technologies will bring attributes of human cognition to bear on the problem of reconstituting systems that suffer the accumulated effects of imperfect software, human error, and accidental hardware faults, or the effects of a successful cyber attack. The overarching goals of the SRS program are to implement systems that always provide critical functionality and show a positive trend in reliability, actually exceeding initial operating capability and approaching a theoretical optimal performance level over long time intervals. Desired capabilities include self-optimization, self-diagnosis, and self-healing; it will be important for systems to support self-awareness and reflection in order to achieve these capabilities.

If there are two or more ways to do something and one of those results in a catastrophe, then someone will do it that way.

Anything that can go wrong, will go wrong.

Shaping the Next One Hundred Years: New Methods for Quantitative, Long-Term Policy Analysis
By Robert J. Lempert, Steven W. Popper, Steven C. Bankes
Copyright 2003

You're going to have equipment challenges, and there's no way to call Pep Boys or Wal-Mart. You've got to have the capacity to
do this on board.
- Sean O'Keefe, NASA administrator