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Wednesday, May 7, 2008

Pursuing the Next Level of Artificial Intelligence

Daphne Koller’s award-winning work in artificial intelligence has had commercial impact

PALO ALTO, Calif. — Like a good gambler, Daphne Koller, a researcher at Stanford whose work has led to advances in artificial intelligence, sees the world as a web of probabilities.

There is, however, nothing uncertain about her impact.

A mathematical theoretician, she has made contributions in areas like robotics and biology. Her biggest accomplishment — and at age 39, she is expected to make more — is creating a set of computational tools for artificial intelligence that can be used by scientists and engineers to do things like predict traffic jams, improve machine vision and understand the way cancer spreads.

Ms. Koller’s work, building on an 18th-century theorem about probability, has already had an important commercial impact, and her colleagues say that will grow in the coming decade. Her techniques have been used to improve computer vision systems and in understanding natural language, and in the future they are expected to lead to an improved generation of Web search.

“She’s on the bleeding edge of the leading edge,” said Gary Bradski, a machine vision researcher at Willow Garage, a robotics start-up firm in Menlo Park, Calif.

Ms. Koller was honored last week with a new computer sciences award sponsored by the Association for Computing Machinery and the Infosys Foundation, the philanthropic arm of the Indian computer services firm Infosys.

The award to Ms. Koller, with a prize of $150,000, is viewed by scientists and industry executives as validating her research, which has helped transform artificial intelligence from science fiction and speculation into an engineering discipline that is creating an array of intelligent machines and systems. It is not the first such recognition; in 2004, Ms. Koller received a $500,000 MacArthur Fellowship.

Ms. Koller is part of a revival of interest in artificial intelligence. After three decades of disappointments, artificial intelligence researchers are making progress. Recent developments made possible spam filters, Microsoft’s new ClearFlow traffic maps and the driverless robotic cars that Stanford teams have built for competitions sponsored by the Defense Advanced Research Projects Agency.

Since arriving at Stanford as a professor in 1995, Ms. Koller has led a group of researchers who have reinvented the discipline of artificial intelligence. Pioneered during the 1960s, the field was originally dominated by efforts to build reasoning systems from logic and rules. Judea Pearl, a computer scientist at the University of California, Los Angeles, had a decade earlier advanced statistical techniques that relied on repeated measurements of real-world phenomena.

Called the Bayesian approach, it centers on a formula for updating the probabilities of events based on repeated observations. The Bayes rule, named for the 18th-century mathematician Thomas Bayes, describes how to transform a current assumption about an event into a revised, more accurate assumption after observing further evidence.

Ms. Koller has led research that has greatly increased the scope of existing Bayesian-related software. “When I started in the mid- to late 1980s, there was a sense that numbers didn’t belong in A.I.,” she said in a recent interview. “People didn’t think in numbers, so why should computers use numbers?”

Ms. Koller is beginning to apply her algorithms more generally to help scientists discern patterns in vast collections of data.

“The world is noisy and messy,” Ms. Koller said. “You need to deal with the noise and uncertainty.”

That philosophy has led her to do research in game theory and artificial intelligence, and more recently in molecular biology.

Her tools led to a new type of cancer gene map based on examining the behavior of a large number of genes that are active in a variety of tumors. From the research, scientists were able to develop a new explanation of how breast tumors spread into bone.

One potentially promising area to apply Ms. Koller’s theoretical work will be the emerging field of information extraction, which could be applied to Web searches. Web pages would be read by software systems that could organize the information and effectively understand unstructured text.

“Daphne is one of the most passionate researchers in the A.I. community,” said Eric Horvitz, a Microsoft researcher and president of the Association for the Advancement of Artificial Intelligence. “After being immersed for a few years with the computational challenges of decoding regulatory genomics, she confided her excitement to me, saying something like, ‘I think I’ve become a biologist — I mean a real biologist — and it’s fabulous.’ ”

To that end, Ms. Koller is spending a sabbatical doing research with biologists at the University of California, San Francisco. Because biology is increasingly computational, her expertise is vital in gaining deeper understanding of cellular processes.

Ms. Koller grew up in an academic family in Israel, the daughter of a botanist and an English professor. While her father spent a year at Stanford in 1981 when she was 12, she began programming on a Radio Shack PC that she shared with another student.

When her family returned to Israel the next year, she told her father, the botanist, that she was bored with high school and wanted to pursue something more stimulating in college. After half a year, she persuaded him to let her enter Hebrew University, where she studied computer science and mathematics.

By 17, she was teaching a database course at the university. The next year she received her master’s degree and then joined the Israeli Army before coming to the United States to study for a Ph.D. at Stanford.

She didn’t spend her time looking at a computer monitor. “I find it distressing that the view of the field is that you sit in your office by yourself surrounded by old pizza boxes and cans of Coke, hacking away at the bowels of the Windows operating system,” she said. “I spend most of my time thinking about things like how does a cell work or how do we understand images in the world around us?”

In recent years, many of her graduate students have gone to work at Google. However she tries to persuade undergraduates to stay in academia and not rush off to become software engineers at start-up companies.

She acknowledges that the allure of Silicon Valley riches can be seductive. “My husband still berates me for not having jumped on the Google bandwagon at the beginning,” she said. Still, she insists she does not regret her decision to stay in academia. “I like the freedom to explore the things I care about,” she said.

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Neanderthals were separate species, says new human family tree

A wax figure representing a Neanderthal man on display at a museum. A new simplified family tree of humanity has dealt a blow to those who contend that the enigmatic hominids known as Neanderthals intermingled with our forebears.
A wax figure representing a Neanderthal man on display at a museum. A new, simplified family tree of humanity has dealt a blow to those who contend that the enigmatic hominids known as Neanderthals intermingled with our forebears.

A new, simplified family tree of humanity, published on Sunday, has dealt a blow to those who contend that the enigmatic hominids known as Neanderthals intermingled with our forebears.

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Neanderthals were a separate species to Homo sapiens, as anatomically modern humans are known, rather than offshoots of the same species, the new organigram published by the journal Nature declares.
The method, invented by evolutionary analysts in Argentina, marks a break with the conventional technique by which anthropologists chart the twists and turns of the human odyssey.

That technique typically divides the the genus Homo into various classifications according to the shape of key facial features -- "flat-faced," "protruding-faced" and so on.

Reconciling these diverse classifications from a tiny number of specimens spanning millions of years has led to lots of claims and counter-claims, as well as much confusion in the general public, about how we came to be here.

Various species of Homo have been put up for the crown of being our direct ancestor, only to find themselves dimissed by critics as failed branches of the Homo tree.
The authors of the new study, led by Rolando Gonzalez-Jose at the Patagonian National Centre at Puerto Madryn, Argentina, say the problem with the conventional method is that, under evolution, facial traits do not appear out of the blue but result from continuous change.

So the arrival of a specimen that has some relatively minor change of feature as compared to others should not be automatically held up as representing a new species, they argue.

The team goes back over the same well-known set of specimens, but uses a different approach to analyse it, focussing in particular on a set of fundamental yet long-term changes in skull shape.

They took digital 3D images of the casts of 17 hominid specimens as well as from a gorilla, chimpanzee and H. sapiens.

The images were then crunched through a computer model to compare four fundamental variables -- the skull's roundness and base, the protrusion of the jaw, and facial retraction, which is the position of the face relative to the cranial base.

When other phylotogenic techniques are used, the outcome is a family tree whose main lines closely mirror existing ones but offers a clearer view as to how the evolutionary path unfolded.

The paper suggests that, after evolving from the hominid Australopithecus afarensis, the first member of Homo, H. habilis, arose between 1.5 and 2.1 million years ago.

We are direct linear descendants of H. habilis. H. sapiens started to show up around 200,000 years ago.

None of the species currently assigned to Homo are discarded, though.

On the other hand, the Neanderthals are declared "chronological variants inside a single biological heritage," in other words, evolutionary cousins but still a separate species from us.

The squat, low-browed Neanderthals lived in parts of Europe, Central Asia and the Middle East for around 170,000 but traces of them disappear some 28,000 years ago, their last known refuge being Gibraltar.

Why they died out is a matter of furious debate, because they co-existed alongside anatomically modern man.

Some opinions aver that the Neanderthals were slowly wiped out by the smarter H. sapiens in the competition for resources.

Other contend that we and the Neanderthals were more than just kissing cousins. Interbreeding took place, which explains why the Neanderthal line died out, but implies that we could have Neanderthal inheritage in our genome today, goes this theory.
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First Wind Powered City

loess hill wind farmRock Port, Missouri is the first 100% wind powered city in the US. Loess Hill Wind Farm, with four 1.25 MW wind turbines is estimated to generate 16 gigawatt hours (16 million kilowatt hours) of electricity annually. 13 gigawatts hours of electricity have historically been consumed annually by the residents and businesses of this town of 1,400 people.

The local electric company, Missouri Public Utility Alliance, will purchase excess electricity when available. They will then supply power when there is not enough wind energy available. Excess wind energy will not be stored but rather fed into the city’s high voltage line, making it an intermittent source of power.

Several factors made this smaller scale project possible. The city has a bluff within the city limits with good resources, John Deere’s Wind Energy financing the project, and proximity to the power grid.

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