Several proof-of-concept worms have been created and two, Cabir and Commwarrior, successfully spread in the “wild” although not very efficiently.

Nonetheless, as portable devices become more fully functional, the risk of a full-blown outbreak is only likely to increase, which makes modelling an outbreak important to devising countermeasures.

, an expert on infectious diseases at Imperial College London and , a researcher at BT’s research lab in Suffolk, UK, created a mathematical model to better understand the way a wireless computer worm would spread between portable devices.

Flu-like spread

In December 2007, another researcher, Steven Myers, at Indiana University, US, developed a model to show how a wireless computer worm might spread between stationary Wi-Fi routers.

The new model adds another dimension by factoring in the movement of people carrying infected or vulnerable devices.

Rhodes and Nekovee’s model considers a crowd of people carrying Bluetooth-enabled smartphones, each with a fixed range for connecting to other phones in the crowd.

Members of the crowd move in a straight line, and at a fixed speed. If a phone is infected with a worm it then has a fixed probability of infecting other devices while they are within range.

The work shows that the spread of a wireless worm can be represented using a common tool for representing virus outbreaks, called a standard mass-action mixing model. “The transmission model is actually very similar to something like influenza,” Rhodes told ��è����Ƶ.

‘Surgical mask’

This means, just like a real virus, a wireless worm would spread most efficiently in a busy setting and could also hop between geographically distant locations, for example aboard a plane.

“A Bluetooth worm’s ability to spread is rooted in person-to-person contact,” says , a chief researcher at Symantec Security Response in the US. So a mass-action mixing model provides a good approximation.

“Knowledge that person-to-person contact, or rather device to device contact, represents a major factor in how a Bluetooth worm spreads is definitely important,” Chien adds.

He also suggests that a simple mitigation strategy would be to disable non-essential Bluetooth communications during an outbreak: “This reduces the contact occurrences and would be analogous to wearing a surgical mask in areas of potential infection.”

Bruce Schneier of security company describes the work as “great and interesting reserach.”

“What’s interesting is that malware depends a lot on the characteristics of the underlying network,” he says. “The phone network is different [to existing networks] and the spreading characteristics will be different.”

However, he doubts whether it will lead to any radically new strategies for defending against such threats. “People subscribe to automatic update, because worms spread faster,” he says. “Fast spreading is a characteristic of wireless worms, too.”

Reference:

10. ‘Transparent’ gadget could trump iPhone interface

Kicking off the list is an ingenious handheld interface that beats ordinary touch screens “hands down”. With a touchpad embedded in its back, instead of in the screen, it promises to help get rid of unsightly smudge marks and also prevent clumsy fingers from obscuring a user’s view.

9. Tripedal robot swings itself into action

In at number 9, is a remarkable robotic balancing act. The three-legged robot in this clip looks unnervingly like a tripod alien from H G Wells’ War of the Worlds, and has a very peculiar way of getting around. It deliberately falls forwards, flipping its body through 180 degrees to swing one leg between the other two and restore its balance. This efficient mode of locomotion could be ideal for exploring other planets. At least, so say the US researchers who built it.

8. Robots with rhythm could rock your world

Continuing the robot theme is , a robot created by US and Japanese researchers that stole people’s hearts in March with his soulful dance moves. Since we first wrote about Keepon, he’s gone on to star in his own music video and feature in .

7. Modular robot’s wriggles show greater flexibility

Next up, it’s yet another robot video, although Superbot – developed by Wei-Min Shen and colleagues at the University of Southern California, US – has a repertoire of tricks that puts the rest to shame. The modular robot can transform itself into a bewildering array of different shapes in order to get around. Various videos show it , , and even .

6. Be the man from Atlantis

At last, a video without robots makes an appearance. This wearable flipper-like contraption, developed by researchers at the US military agency DARPA, is meant to help Special Forces divers swim more speedily. The device was spied by an eagle-eyed ��è����Ƶ magazine features editor at the conference in California, US.

5. A programmable robot from 60 AD

At number 4 it’s an ancient ““, built by our very own Ben Crystall. The wheeled contraption can be “programmed” using a series of ropes and pegs, and was first designed some 2000 years ago by the Greek engineer , as this feature article explains. Ben even cut up his son’s scooter to build the device, so he was undoubtedly relieved that readers liked the clip.

4. Tangible display makes 3D images touchable

The next video is science fiction made real – a smart screen that makes 3D objects solid and touchable. A force-feedback glove worn by the viewer matches the shape of an on-screen 3D object, creating the illusion of holding, as well as seeing, a solid object. The researchers behind the idea, from NTT labs in Japan, think it could be ideal for long distance interactions, like shaking hands or patting someone on the head. Could it revolutionise long distance communications?

3. Interactive paper sounds exciting

A way of bringing flat images to life makes it to the number 3 slot. Interactive paper-based material, developed in Sweden, turns static images to life using conductive ink and an array of cardboard speakers. The researchers created 2-meter-tall billboards that respond to users’ touch by playing music clips, or spoken dialogue.

2. Desktop fabricator may kick-start home revolution

Our second most popular video is of a desktop device that could bring about a revolution in home manufacturing. The can churn out almost anything your heart desires, from a perfectly sized plastic washer or to a . Most importantly, the device is much cheaper that earlier prototypes – costing just a few thousand instead of a few hundred thousand dollars to build. So, what are you waiting for? Get fabbing!

1. The stuff of dreams

And, finally, the most popular video of the year actually appeared right at the very end of 2006, in a round-up of clips showing weird and wonderful materials. Five fantastical substances featured in the story, including fluids that solidify when stressed, liquids that flow without friction, and ferromagnetic gloop that that reacts spectacularly to a magnetic field.

Video: Twine preview

Making sense of an ever-increasing number of emails, web links, feeds, and social networking contacts is tough for even the most organised person. But a new website promises to make the task much easier by gradually learning to identify relevant information in this deluge of data.

Radar Networks, a company based in San Francisco, US, is betting it can make sense of all the information collected by a web user with software that learns to distinguish between people, places, companies, and more.

Its website, called , harnesses the philosophy at the core of a discipline called the “semantic web”.

The semantic web is an extension of the current web, but where information is stored in a machine-readable format. It should allow computers to handle information in more useful ways by processing the meanings within documents instead of simply the documents themselves. To an extent some web tools, such as tags, already tap into this philosophy.

Data overload

Although only available to only about 100 testers, Twine has caused a stir among web experts because it is one of the first commercial ventures to try harnessing the semantic web.

Other semantic start-ups include the search engines and , and a free semantic database service called .

As a technology that could transform the way websites work, the semantic web is often also associated with the term “Web 3.0”.

Twine uses a semantic approach to act as a personal organiser, bookmark service, and a social network combined. A user adds information by creating a note, forwarding an email, uploading a document, or tagging a web page.

“Twine is a service that helps you de-fragment your digital life,” says company founder . “Today we all have different bits of data in different places, there is no easy way to see all you know, and share and manage it.”

Twine annotates information semantically, highlighting the names of people or companies mentioned in an email, for example, and grouping these names into two categories at one side. This allows a user to explore connections between different documents, and to see their information organised in a more insightful fashion, Spivack says.

Linguistic approach

Various software tools such as the (RDF) and the (OWL) allow information to be annotated in machine-readable fashion.

But currently very little information available on the web is presented this way. So Twine has to perform the annotation itself. It does this by using a combination of and machine learning techniques. That is, it takes techniques from linguistics, understanding meaning through words, sentence structure, or grammar.

The machine learning process will, over time, allow Twine to learn from user behaviour, Spivack says. For example, it may ‘learn’ over time that what it thought was the name of a person is in fact the name of a company.

“I like to think that in the order of 10 years it will become more like an assistant than a web page,” he says. There are also plans to provide tools that will allow other websites to upload information to Twine. “That includes a range of social networks and could even include companies with proprietary data, for example, stock market data,” Spivack says.

Advertising 3.0

At the same time, Twine could enable entirely new forms of advertising. “If we understand about your interests we can provide more relevant adverts,” Spivak says. “If they can become 100% relevant, they actually become content, not adverts.”

Many experts believe Twine and other semantic web technologies have great potential, but are keen to test them before making a judgement.

“I think it’s a good application that can exploit the current semantic web technology”, says Tim Finin, a web researcher at the University of Maryland in Baltimore, US. “[But] I’m hesitant to describe it as ‘the next big thing’.”

‘Legacy information’ or older pages on the web could be a serious problem for a semantic website, points out Nigel Shadbolt, a semantic web expert at Southampton University in the UK. This is because older pages will not have the underlying annotations that the semantic web harnesses to extract meaning. Furthermore, and paradoxically, there is also a risk of overloading users with new information. “That’s a very tough problem,” he says.

Another issue may be the amount of excitement building around semantic web start-ups. “With any new technology there’s always a risk of hype,” says , a semantic web researcher at Hewlett-Packard labs in Bristol UK.

“I think a lot of people get hung up on the word ‘semantic’,” he says. “It really means an information-rich model, but what some people might take it to mean is that there is a human-level understanding.”

Images uploaded to photo-sharing websites like could find a surprising new application – they could help build accurate 3D models of the real world.

Creating realistic 3D models of the real world represents the next stage in digital mapping, providing users with a more immersive way to explore a destination using a computer. But constructing 3D models of real structures normally involves using carefully positioned stereo cameras or laser ranging equipment to analyse them.

Now, Michael Goesele of TU Darmstadt in Germany and colleagues at the University of Washington and Microsoft Research, both in Washington state, US, say they have developed a much simpler method. It uses software that recreates real structures in 3D by analysing hundreds of different public images.

“The system provides an opportunity to use the billions of user-contributed images available online to ‘reconstruct the world’ without relying on specialised equipment,” Goesele told ��è����Ƶ.

Holiday snaps

Goesele and colleagues realised that sites like Flickr might hold huge potential for remote stereo imaging, as long as the images uploaded to them could be analysed correctly.

For example, there are more than 200,000 images of Notre Dame Cathedral in Paris on Flickr. “We were curious and wanted to try how far we could push a reconstruction system by running it on these very general, real-world datasets,” Goesele says.

But using holiday snapshots in this way proved problematic because such photos are shot from a wide variety of angles and distances, with contrasting lighting. Also, more often than not, such pictures have someone standing directly in front of the object of interest.

Similar images

So the software devised by Goesele’s team has to first find images that are suitable for stereo comparison. After the images are collected with a search, it weeds out those that are too dissimilar.

Then it uses a combination of different computer vision techniques to create a 3D model of the scene. A process called “structure from motion” identifies 3D points across the surface of a building using images taken from different angles. The rest of the surface is then built on top of these points using the collected images. See a video of the process .

The approach was found to be surprisingly resilient to variations in lighting and perspective and, often, as accurate as existing 3D reconstruction methods.

Reconstructing Rome

“The quality of the reconstructions we can achieve from mere internet data is comparable to models acquired with traditional methods such as very expensive laser scanning systems,” Goesele says. “Overall, we see this as a very first step into an exciting new area – think of reconstructing Rome from the about one million images available on Flickr alone.”

Andrew Hudson–Smith of the Centre for Advanced Spatial Analysis at University College London believes the technology could have huge future potential.

“The paper paves the way for a modelling tool which could change the face of virtual city construction,” he told ��è����Ƶ. “The authors’ comparison with costly laser-based systems is of particular note as these systems are the current benchmark for accuracy, especially when used for planning or virtual heritage.”

Hudson–Smith believes making the technology publicly available could spur on 3D mapping. “What is exciting would be the release of the software to the general public,” he says.

Video: The system enables a 3G video cellphone to record an object and find out about it in an online database

Video-equipped cellphones could soon offer simple way to find useful information about the surrounding world.

Currently, the best way to use a cellphone to find information about, for example, a product or an ad on a wall is by entering an internet search query with the keypad. Soon, however, it may be easier to simply record a video clip of an item of interest and have your phone tell you about it instead.

Researchers at in France have developed technology that makes this possible using any ordinary 3G cellphone equipped with a video camera.

The prototype system, dubbed the Pocket Supercomputer, offers a simple way to seek out useful, hard-to-find information, says who led the system’s development at Accenture.

SIFTing objects

If a user records a video clip of, say, a foreign food item, the system can automatically identify ingredients that might cause an allergic reaction. Similarly, when shown a book, it can quickly perform an online price comparison, or find a review (see video, top right).

Live video footage is fed from the handset to a central server, which rapidly matches on-screen objects to images previously entered into a database. The server then sends find relevant information and sends it back to user.

The central server uses an algorithm called the to match objects. The algorithm uses hundreds or thousands of reference points, corresponding to physical features such as edges, corners or lettering, to find a match. The process works no matter how the object is oriented, but objects must first be carefully imaged and entered into the central database.

Creating a database containing 5000 items takes about a day, Linaker says, although it then takes just a few milliseconds to match an object. “Eventually you could imagine having one enormous [general purpose] database.”

Advances in image recognition have prompted several other companies to research similar cellphone search technologies. Microsoft has a system called , that lets users to take snapshots and send them off for identification.

Another system developed by Evolution Robotics of Pasadena, California, called , also uses video footage to identify objects, and is already available in Japan.

Robot navigation

Krystian Mikolajczyk, a computer vision researcher at the University of Surrey, Guildford, UK, says it is preferable for image processing to be done remotely. “It’s hard to store a large database on the cellphone,” he says. “It is also difficult to propose generic software for any brand and model.”

“This is the type of application for which SIFT was developed,” adds , who developed the SIFT algorithm in 2004, and who is a computer vision expert at the University of British Columbia in Vancouver, Canada.

“I think it will be a useful for cellphones – a very convenient method for users to get information about the objects and locations in their surroundings,” Lowe told ��è����Ƶ.

He does not think cellphone object recognition will become an instant hit, though: “It will take some time for consumers to learn about such systems and start to incorporate them in their daily life”.

Even so, Accenture has plans to use the Pocket Supercomputer for research purposes. Linaker says it could work as an aid for blind people, as a tool for studying cellphone usage, and even to help remote robot navigation.

Video: LittleDogs from USC and CMU cover treacherous terrain using different algorithms

A timid-looking four-legged robot about the size of a Chihuahua might seem like an unlikely companion for soldiers of the future.

Yet one such robot called LittleDog could help researchers create more sophisticated robotic assistants for military personnel, including automated “pack-mules” capable of hauling heavy loads over tough terrain.

LittleDog is remarkably agile for a robot when faced with treacherous, uneven terrain. Researchers can also fine-tune its movement to make it even faster and more agile on rough ground. LittleDog was created for the US Defence Advanced Research Projects Agency (DARPA) by US robotics company .

And now DARPA has selected six university research teams, including ones at MIT and Stanford, to compete to develop the best algorithms for controlling the robot pup. The agency hopes this will help identify the ideal adaptive strategy for moving over irregular surfaces.

The robot has three motored joints on each leg, and its movements are controlled precisely by an on-board computer. An internal gyroscope lets the robot sense its orientation, while an external motion-capture system monitors the precise position of each limb and joint as it moves.

Monthly testing

The six teams have each been given a LittleDog and a section of nearly identical artificial terrain for the robot to cross.

The video (top right) shows two of the robots in action. Videos of other LittleDogs can be found , and .

Every month, following rigorous testing in their own labs, each team sends its control algorithms to DARPA, and the agency then tests these on an identical LittleDog and the same fake terrain to determine which lets the robot move fastest.

Over the course of 2008, new algorithms will be tested by DARPA on more unpredictable, previously unseen, terrain. So the algorithms used will need to quickly identify footholds and the best route across. At the end of that year, an overall winner will be announced.

Dynamic advances

“It’s getting a bit more competitive,” admits , a member of the LittleDog team at the Institute for Human and Machine Cognition (IHMC) in Florida.

Pratt notes that most LittleDog teams are starting to move from a static approach that involves keeping three of the robot’s legs rooted to the ground to a more dynamic one that sees only two legs planted at any time. “It’s a lot trickier because you have to take dynamics into consideration,” he told ��è����Ƶ. “Walking becomes more like controlled falling.”

Although the current set-up uses an external motion capture system, LittleDog’s descendants will ultimately need to examine the terrain ahead for themselves. “It would have to identify the best places to step,” Pratt says.

Boston Dynamics has previously demonstrated a much larger four-legged robot called BigDog. Internal sensors and motors allow this robot to rapidly regain its balance after slipping or being pushed, but BigDog is unable to tackle the kind of irregular terrain faced by LittleDog.

Trial and error

“Legged locomotion on extreme terrain is a very complex task for robots,” says Dennis Hong, an expert on walking robots at Virginia Tech, US, who is not involved with any of the LittleDog projects.

Hong adds that adaptive learning offers the best hope of tackling such a complex problem. “Think of a human baby learning how to crawl,” he says. “Initially, the baby does not know how to coordinate the complex motion of its limbs for crawling, but learns by trial and error, and eventually learns how to walk and even run.”

Max Lungarella, a robotics researcher at the University of Zurich in Switzerland, says the project provides a great opportunity for comparing different approaches. “What is really interesting about the whole project is the idea of a common research platform,” he told ��è����Ƶ. “A lot of research in robotics is done on platforms built ad hoc.”

Lungarella also believes robots capable of covering such hazardous terrain could find plenty of uses, “from search and rescue operations to exploration of unknown areas, and maybe an alternative form of transport for humans in terrains inaccessible by vehicles on wheels like mountains or forests.”

Robert Richardson, at the University of Manchester, agrees. “Robotics is generally moving away from the three D’s (dull, dirty and dangerous), towards the three E’s (education, entertainment, and everyday),” he says. “I think there will be no shortage of applications for such a system.”

Amateur stargazers have a new way to explore the heavens – with an update to Google’s free global mapping application .

This program shows users a globe of the Earth, which they can search for landmarks, high-resolution images and information tagged to the planet by other users. Google says the original application has been downloaded more than 250 million times.

The new feature, called Sky, adds a wealth of astronomical data to Google Earth, including images of more than 100 million individual stars and 200 million galaxies.

At the press of a button, a user sees their perspective shift upwards, revealing the correct constellation of stars for their selected position on Earth. They can then pick out particular stars or planets manually, or using the search field, and zoom upwards to see more detailed images and additional information. Some 20,000 celestial objects can be searched for by name using the Sky feature.

Astronomical imagery and information comes from a number of scientific organisations including the , the , , the and the .

Although a number of stargazing programs already exist, such as , and , , an astronomer at University College London and president of the says Sky has its advantages. It is simpler than many of these programs, he says, and will appeal to many amateur astronomers because it lets them upload and pin their own images to the sky.

“It could be a kind of astronomical YouTube,” says Diego says. “Amateur astronomers will have a fantastic opportunity to display their own work. They discover a lot of supernovae; I think Google are going to be overwhelmed with information.”

Jason Chuck, a product marketing manager at Google, hopes the tool could make a useful teaching tool. “Even if you don’t know a lot about space, you can zoom out and it can guide you,” he says. “If you are teaching stuff in the classroom it can be your guide.”

accounts at a prominent computer security conference on Sunday, a US college student was humbled to find his own account disabled.

Rick Deacon, a student at the University of Akron in Cleveland, Ohio, US, revealed several techniques aimed at gaining access to other users’ MySpace accounts at the conference in Las Vegas, Nevada, US.

Shortly after his demonstrations, however, Deacon found a message in his MySpace inbox informing him that his account had been suspended for violation of the site’s terms of use. “In retrospect, I should have used a dummy account,” he told AFP.

The hacking techniques demonstrated by Deacon included a technique known as cross-site scripting, which involves adding extra information to a trusted web page in order to mislead a user or to perform to a remote action on their machine, via the web browser.

Cookie catching

By tricking a victim into clicking on a link, Deacon showed that it is possible to capture the web browser file, known as a “cookie”, which automatically logs a user into the site. This can then be used to access their account, Deacon said.

The vulnerability has not been verified independently, but Deacon appeared to demonstrate it live before his audience. He also claimed that he alerted MySpace to the problem some weeks ago but that the site had not responded. Now, however, MySpace has patched the vulnerability.

Bruce Schneier, a renowned computer security expert with , based in California, US, says the demonstration highlights a trend in the computer security community, which has seen experts probe social networking sites more and more.

“It’s not that MySpace is worse than anything else,” he told ��è����Ƶ. “It’s just that social networking sites are becoming juicier targets.”

Risky business

A survey carried out by the and software firm in October 2006 suggests that people who use social networking sites often engage in “risky” behaviour online. Some 74% of users said they would divulge personal information, including email addresses and birthdays, through such sites. The report suggests that this could increase the risk of online identity theft.

“As more and more people rely on MySpace for their social interactions and for their personal information, you’re going to see more of these hacks,” Schneier says.

Deacon appeared humbled by having his accounted deleted. “If you talk to them, tell them I’m sorry,” he told reporters at DEFCON. “I’ll keep my new MySpace account as what it should be – a place for talking to my friends.”

See a gallery of images

Engineers are struggling to understand how the I-35W bridge spanning the Mississippi in Minneapolis, US collapsed so catastrophically on Wednesday, killing at least 7 people, as cars and trucks were hurled into the water below. With 20 people still missing and 60 in hospital, the death toll is expected to rise.

The eight-lane bridge connected the east neighbourhood of Minneapolis with the west neighbourhood of the University of Minnesota (see ).

It suffered a total structural failure at 1805 local time, as the whole middle section of the bridge, along with some 50 vehicles, crashed into the river. A freight train sitting beneath the structure was also partially crushed, although this did not cause further injuries.

There was little unusual about bridge design apart from it having no supporting pillars in the water. Instead, the 580-metre-long platform was supported by a single 140-metre-long steel arch spanning the river. According to , the governor of Minnesota, the bridge was last inspected in 2006 and no structural defects were found.

‘Combination of factors’

“This is an amazing collapse,” says Tom Foulkes, Director General of the UK . “I have never seen anything like it before. For the entire central span to collapse like this is most unusual – possibly unique.”

The bridge was reportedly undergoing maintenance work when the collapse occurred, and this could be a key factor for engineers investigating the disaster. “That would be another important line of enquiry,” says Foulkes.

But other causes are likely. “Major failures are often due to a combination of factors, rather than a single cause,” Foulkes says. “Fatigue cracks, corrosion, ship impact, bearing failure, scour or damage to the supports – all these could contribute.”

A Civil Engineer to Minnesota Department of Transportation, commissioned in 2001, noted that the bridge should be considered a “non-redundant structure”. This means that if any key structural feature fails, the bridge would collapse completely.

This report found no evidence of fatigue cracking on the main truss, floor truss or deck truss. Each truss is a combination of individual jointed beams that provides support for the overall structure.

In 2003 the Department of Transportation described the condition of I-35W as “fair” on its , stating that it “meets currently acceptable standards”.

Video: Researchers demonstrate a vulnerability that can be used to capture files from an iPhone

A trick that could allow hackers to hijack Apple’s new iPhone has been revealed by a US computer security company.

Experts working for , based in Maryland, US, say it is possible to steal files and remotely operate a handset if a webpage containing malicious code is loaded.

According to a (pdf) released by the company, its researchers used an as-yet undisclosed software vulnerability to hijack an iPhone.

The researchers say the vulnerability can be used to carry out unauthorised commands on a targeted device, once a user has loaded a suitably modified webpage. A user could be tricked into doing this via a link in an email or text message, or even by being served a fake webpage through a hijacked Wi-Fi access point.

In one experiment, the researchers created a webpage that triggered an iPhone to connect to a remote server and forward previously sent text messages (see video, top right). In further tests, the researchers say they were able to make the phone vibrate, dial given numbers, send text messages and activate its microphone.

‘Genuine hack’

There is no evidence that the exploit has been used in the wild. The company says it revealed details to Apple on 17 July and plans to release the technical details publicly on 2 August.

Apple spokeswoman Lynn Fox told The New York Times that the company was investigating. “We’re looking into the report submitted by ISE and always welcome feedback on how to improve our security,” she says. “Apple takes security very seriously and has a great track record of addressing potential vulnerabilities before they can affect users.”

, a computer security expert at Columbia University, New York, US, says the greater functionality offered by the iPhone naturally leads to increased security risks.

“This looks like a very genuine hack,” he told the newspaper. “We’ve been hearing for a few years now that viruses and worms were going to be a problem on cellphones as they became a little more powerful, and we are there.”

Unprecedented media interest in the iPhone has undoubtedly also lead to extra scrutiny by security experts.

For example, users have to sign up with cellphone network AT&T before using the phone. But within a week of its launch, a well-known Norwegian computer programmer found a way to use most of the phones functions without signing up (see iPhone security cracked after one week).