Archive for January, 2006

Neural Nets Demystified

Tuesday, January 31st, 2006

A mention of neural nets tends to send many otherwise reasonable people into an irrational state. The term often conjures images of the terminator, probably with a dash of I Robot thrown in there for good measure, where anti-social nerds with dubious ethics and hygiene somehow lose control of their creations and wreak havoc upon us all when their neural nets become sentient and decide they’ve had enough.

It also tends to show up in papers in all kinds of fields with complex systems, typically with little explanation of why a neural net is chosen, why that specific implementation was used, how they tuned it, and how they managed their data sets. Fortunately for us all, there is often a sort of vague implication that “it’s learning things even we don’t know!” about the system in question.

Sadly (or happily, depending on your point of view), neural nets aren’t quite that sexy when you get into the nitty gritty details. If you can recall grade 10 physics and trying to fit data to a function, then you’re pretty much most of the way there. Essentially, a neural net takes your set of inputs, gives them weights, sums them up, and runs them through a special function. A graphic often helps to visualize this. You can chain these together at your whim, and at the end you get a bunch of numbers which represent your output. The ‘learning’ in most cases is simply the adjustment of the weights based on whether the output matches what you hope it would.

Of course, one downfall is that it’s virtually impossible to pull out any sort of system information from a reasonably sized neural net, it’s like fitting a curve well but having no idea what curve you fitted it with. Once your neural net has learned its function, you don’t necessarily have any new information about how the system is working, it’s a black box in many senses, and just like in any function approximation method, problems of input size and accuracy remain, and neural nets are not immune to the problems of overfitting and underfitting.

In short, it’s not a magic bullet; yes, they can approximate noisy non-linear functions quite well, but no, that doesn’t mean we understand any better how the system works, and may be a sign we’ve just sort of given up trying to reason about the dynamics of the system. So the next time you read a paper that mentions using neural nets, let it activate your meaningless technical jargon alarm and ask yourself why they’re doing it.

Bloggers Beware!

Monday, January 30th, 2006

Did you know that the Beeb (BBC) has a ‘Pentagon Correspondent’?

His news looks grim for the web, so start packing up your servers.

climate change in the news…

Monday, January 30th, 2006

Climate Change made it to the front page! At least on BBCCBC has relegated the article to the middle of “health and science”, and I couldn’t find a mention of it in the NYTimes. The UK has comissioned and just released a report on the effects of climate change, entitled “Avoiding Dangerous Climate Change. Check it out… The BBC Q&A on the topic brings up the issue of population growth and climate change, a taboo topic in much of the climate discussion. A BBC writer has an interesting article on individual footprints – citing concerns with physically bringing people to a huge conference, and considering the HUGE impact of the COP in Montréal…“Earth is too crowed for Utopia”

From the front at the WEF

Sunday, January 29th, 2006

A blog-boast: The World Economic Forum blog

An excerpt:

At one point Klaus Schwab asked Clinton how he would advise future U.S. presidential candidates including McCain — or ”the person you’re married to.” “In these cultutrally charged times, I just want to make clear that I am not married to Senator John McCain,” Clinton quipped, drawing a roar of laughter from the crowd.

Take a break from bad news

Saturday, January 28th, 2006

And ogle the new planet, Ogle.


European Southern Observatory

Maybe it’s not so bad…

Friday, January 27th, 2006

While we all wait in fear for the environmental values of the new conservative government to shine through, our beloved CBC offers up something that could be considered consolation…apparently, Stephen Harper DOES care about the environment! Here is an excerpt:

Harper brought up his asthma during an October 2002 House of Commons debate, when an NDP member of Parliament accused his party of not caring about the environment because it opposed the Kyoto Protocol.

“Mr. Speaker, it always amazes me that a number of Canadians on that side of the spectrum, particularly in the NDP, seem to think they are the only people who have any concerns about living in the environment. I do not know where they think the rest of us live,” Harper said.

“We all have fairly serious concerns about the environment and about our health. In my personal case, we are talking about the contents of the atmosphere and I have been a lifelong sufferer from asthma. I am very concerned about my respiration and how this agreement will affect my respiration.

Obviously, we foolish (marxist even? ha!) environmentalists have nothing to fear. Until clean air becomes an excludable good that is…

Privacy

Thursday, January 26th, 2006

What is this notion of privacy? Felix Stalder proposes in this article that privacy is a cultural construction connected to the dominance of print media, and that now, with the rise of electronics, traditional notions of privecy will erode…

Hacker Attacks

Thursday, January 26th, 2006

Virtual activism in the form of “denial of service” places a barrier to Internet access. Some say this is actually opposite to what environmentalists want – education, support, and action. Others say it is taking advantage of the technology to reach goals – directly interacting with governments and showing strong support for their cause.

Does virtual activism attract attention?

Thursday, January 26th, 2006

The 2000 UNFCCC human dike attracted a huge amount of media attention in the UK. It was a great photo opportunity when officials stood at the base of the dike. It was clear: waters were rising due to climate change and the officials and protestors were willing to stand up for change. Can anyone give an example of virtual activism having a similar effect? Does simply passing the pictures over the virtual wires increase the range and thus enhance the physical demonstration?

Democracy

Thursday, January 26th, 2006

The Death of Distance by Frances Caircross claims this century is dominated by lowering the cost of transporting ideas. The Internet is thought to have changed information transmission to better inform citizens to change the balance of power with governments. Does the Internet’s free communication improve democracy? Is that pushing the use of a communication tool?

Our wired lives

Thursday, January 26th, 2006

The hazards of a wired and watched society.

Expanding Cyberspace…

Wednesday, January 25th, 2006

“The future is here. It’s just not evenly distributed yet” . The ubiquity of the internet in the western world has raised a concern among many cause-searching souls, who seek to reduce the “digital divide” – it is unaceptable that the Internet, such an important tool to the daily functioning of our society, should be inaccessable to such a large portion of the global population. So, is IT really that useful of a priority in developing nations? Based on this site, IT will save the world. Or at least Africa. But really, what are the extended implications of such a project? Could a so-called “digital colonialism” potentially become a problem? UNESCO has decided that virtual activities are important enough to warrant a “world summit on the Information Society”, held last november. Some topics covered included “Cultural diversity in knowledge societies”, “Multilingualism for Cultural Diversity and Participation of All in Cyberspace” and “freedom of expression in cyberspace”. Sounds almost more exciting than climate change…

virtual reality

Wednesday, January 25th, 2006

To what extent is virtual reality dependant on physical objects? An article (albeit and out of date one) discusses the missed out on “goggles and joystick” style virtual reality games of the mid 1990s, and a new sort of virtual reality “art” that some people at U of Illinois have thought up. The article doesn’t get into the philosophical considerations of the physical role of technological objects in our so-called virtual lives, but leads one to consider the phsical role of technology. Don Idhe (no link, you will have to find a physical copy to interact with) discusses the role of technology for humans, and the way that technological objects have influenced humankind’s interaction with the environment. If a technological object is something that enables increased activities thorugh its use, the activities enabled by our increasingly able technologies go through the roof. Or do they? Given the amount of power humans have derived from their technological dependance, how do virtual technoligies, that are not only acted upon but can act themselves (to an extent), alter that power structure?

The Ascent of Man

Wednesday, January 25th, 2006

Here it is...

Back in the 1970′s, J Branowski hosted a TV brilliant series on the Beeb. It was aptly titled, ‘The Ascent of Man’. In short, it confronts the possibility that there is something profoundly wrong with the technocratic society we are growing to accept.

In a fitting turn of events, you can retrieve all 8 gigabytes of the entire series with this software, and with this link.

Even with high-speed internet, however, it might take 2 to 3 days.

Environmentalists and Google Earth

Tuesday, January 24th, 2006

An article in the San Francisco Chronicle shows the ways in which “desktop satellite tools” are changing the way environmentalists work. Google Earth is fast becoming the killer app for geographic information systems, or at least it’s the killer GUI for GIS.

Here’s the Sierra Club’s application of Google Earth to alert the US public to the problems of drilling in the Arctic National Wildlife Refuge.

Also look at Whirlwind, NASA’s geo-explorer, a blog that tracks all things Google Maps, and a blog that finds environmental problems by surfing Google Earth.

Why are Google products the killer app and not online GISs such as ArcIMS and MapXtreme? Because, in one easy interface, Google Earth drapes satellite images over three dimensional topography (digital elevation models or DEMs). Users can not only see the 3D data from a planimetric or top-down view, they also can fly or walk over the landscape. The interface allows editing: users can annotate places and activities on the images with labels or attributes (e.g., information about the place or photos). A recent arrangement between ESRI and Google allows users to add their own drapes. All this is available to anyone else on the web who has downloaded the Google Earth application. Obviously something like Google Earth and Google Maps have far less functionality than a GIS. But consider that most online mapping software makes it very difficult to create and maintain applications and provides clunky interfaces. And the online mapping software comes with no data. Then you see why Google products hold so much potential.

Pay more, speed up

Monday, January 23rd, 2006

Since the beginning of the World Wide Web, Internet companies have flourished, in part, because they could deliver information freely over telephone lines. Whatever else the costs from ISPs or subscription services, companies did not have to bear the costs of developing or maintaining the dissemination infrastructure.

Now telephone companies in the U.S. want to profit for providing the pipes. They’re lobbying the U.S. federal government to be allowed to speed up or impede certain websites. Their plan? To give the companies that pay the fast ride. Companies that don’t pay or pay less will be slowed down. Think of Yahoo paying AT&T to have the fastest speed. What might happen to Google? And what about Voice over IP, the major competition to phone service? Hmmmm. I foresee some degradation of service.

Some company heads are getting mad:

In a November Business Week story, AT&T Chairman Edward E. Whitacre Jr. complained that Internet content providers were getting a free ride: “They don’t have any fiber out there. They don’t have any wires. . . . They use my lines for free — and that’s bull,” he said. “For a Google or a Yahoo or a Vonage or anybody to expect to use these pipes for free is nuts!”

This is far from a pipedream:

an executive with BellSouth was quoted saying that the company would consider charging Apple five or 10 cents extra each time a customer downloaded a song using iTunes.

Besides being irritated that electronic commerce will cost more, I’m worried about the impact on online activism. The same technology allowing the telephone company to speed up preferred customers and impede others, can allow phone companies to reject politically objectionable websites. Want Greenpeace? For some reason, it won’t download.

Demographics

Sunday, January 22nd, 2006

The Internet is thought by some to reach different demographics of individuals as it is considered a global network. Is that the case? Organizations find their websites may not be attracting people as only those who have been informed physically and are interested in the issues visit their sites.

Climate Change and eActivism

Sunday, January 22nd, 2006

Most NGOs use online tools for communication purposes, this is no different then any other organization. Why is the use of computer-mediated communication so important for climate change issues and NGOs? Because the problem is: Global? Complex? Requires clear communication? Or is it just because it’s different and considered cool?

Science on the demise

Saturday, January 21st, 2006

Richard Smalley, Nobel Prize winner, discoverer of the ‘buckyball’, succumbed to leukemia on October 28, 2005. He was 62. He had been conducting a campaign of awareness about the scarcity of US talent going into hard science, and I feel that he speaks on behalf of a far greater group.

The double-edge of technology in environmental problems and solutions is no small area of study. Many argue sides of Science and Policy in a semi-vindictive back-and-forth, but wherever the “truth” lies, it is undeniable that the interest and participation in sciences is dropping.

A while back, the New York Time put together a good reflection on the topic. Today, reporting on the pop-culture perspective of science, The Beeb offers something new.

Apocalypse Now

Monday, January 16th, 2006

Human-induced climate change has caused so much damage that the Earth is past the point of no return. So says, James Lovelock, creator of the Gaia theory, in his new book Revenge of Gaia.

According to the book, not only is global warming increasing but effects like melting polar ice are working in a positive feedback loop. The impacts will only accelerate and will create world-wide havoc much sooner than expected. This warning is not new. The rapidity with which it’s happening, is. And Lovelock warns that the change is irreversible so countries need to prepare for the worst.

Over the coming decades soaring temperatures will mean agriculture may become unviable over huge areas of the world where people are already poor and hungry; water supplies for millions or even billions may fail. Rising sea levels will destroy substantial coastal areas in low-lying countries such as Bangladesh, at the very moment when their populations are mushrooming. Numberless environmental refugees will overwhelm the capacity of any agency, or indeed any country, to cope, while modern urban infrastructure will face devastation from powerful extreme weather events, such as Hurricane Katrina which hit New Orleans last summer.

The prognosis is as depressing as can be imagined: the destruction of civilization. What will be left is “a broken rabble led by brutal warlords.”

His advice? Stockpile food in a narrow Arctic belt that will be habitable for the few remaining humans. Compile a text for the survivors, written “on durable paper with long-lasting print”, containing all necessary scientific knowledge so that humanity can rebound as quickly as possible. I’m sure Lovelock got this idea from the science fiction novel, Lucifer’s Hammer by Larry Niven and Jerry Pournelle. Even though the book speculated about an Earth after a comet strike, it’s still a valid idea for a world destroyed by a rise of 8 degrees celsius. (And ironic since Niven doesn’t believe the climate change is human-induced.)

This is considered so important that, in addition to Lovelock’s piece, Britain’s Independent newspaper has devoted two articles to it, here and here.

It will be interested to see how climate change scientists react to this book publicly. I’m guessing that they’ll tone down Lovelock’s assertions. I don’t know whether the majority of scientists believe in Lovelock’s prognosis but feel it won’t play well in the press or believe that climate change ultimately can be halted. The public? It’s like a novelization of The Day After Tomorrow so I can’t foresee any major reaction. The paradox is, as much as a film such as this distorts the science of climate change for dramatic effect, it captures the magnitude of Lovelock’s predictions.