Association for Computing Machinery
Welcome to the July 11, 2011 edition of ACM TechNews, providing timely information for IT professionals three times a week.

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HEADLINES AT A GLANCE


Improving Recommendation Systems
MIT News (07/08/11) Larry Hardesty

Massachusetts Institute of Technology (MIT) professor Devavrat Shah thinks that the most common approach to recommendation systems is fundamentally flawed. Shah says recommendation systems should ask users to compare products in pairs instead of using the standard five-star scale, as both Amazon and Netflix do. He believes that combining the rankings into an overall list will offer a more accurate representation of consumers' preferences. Shah, MIT professor Vivek Farias, and students Ammar Ammar and Srikanth Jagabathula have demonstrated algorithms that put the theory into practice and they have created a Web site that uses the algorithms to help large groups make collective decisions. The MIT algorithm predicted car buyers' preferences with 20 percent greater accuracy than existing algorithms. The algorithm reduces the number of possible orderings, which would be more than 3 million for a list of just 10 items, by throwing out the outliers and selecting subsets of data. The algorithm also uses an items rank in each of the orderings, combined with the probability of that ordering, to give the item an overall score, which is used to determine the final ordering. "They've really, substantially enlarged the class of choice models that you can work with," says University of Southern California professor Paat Rusmevichientong. "Before, people never thought that it was possible to have rich, complex choice models like this."


Project Works on Robots That Can Recognize Human Emotions
The Engineer (United Kingdom) (07/08/11) Stephen Harris

U.K. researchers believe humans will be more likely to accept robots as part of everyday life if they are capable of recognizing human emotions. As part of the European Union-funded LIREC project, a team from Queen Mary, Hertfordshire, and Heriot-Watt universities will conduct psychological experiments on humans to determine how they recognize and understand emotions. The team will use that research to develop mathematical models that enable robots to read social situations. The robots will use the software to recognize movement in people's faces, understand their emotions, respond to human emotions, and change their behavior accordingly. "It's a question of finding out how biology does it and trying to build systems that do the same," says Queen Mary professor Peter McOwan. "We want to have a better understanding of how human brains process information about faces and build those ideas into the next generation of socially-aware robotic companions." The researchers also are studying how to integrate the robots into homes, schools, and offices. The team will test robots in all three environments and wrap up the project in 2012.


Air Power: New Device Captures Ambient Electromagnetic Energy to Drive Small Electronic Devices
Georgia Tech Research News (07/07/11) Rick Robinson

Georgia Tech researchers have developed a technique for capturing and harnessing the energy transmitted by radio and TV transmitters, cell phone networks, and satellite communications systems and are using it to power networks of wireless sensors, microprocessors, and communications chips. "We are using an ultra-wideband antenna that lets us exploit a variety of signals in different frequency ranges, giving us greatly increased power-gathering capability," says Georgia Tech professor Manos Tentzeris. The researchers used inkjet printers to combine sensors, antennas, and energy-scavenging capabilities on flexible materials to create self-powered wireless sensors. The devices can capture transmitted energy, ranging from FM radio to radar, and convert it from AC to DC, storing it in capacitors and batteries. Additional tests on scavenging TV bands have resulted in power in the range of hundreds of microwatts, and the researchers expect that multi-band systems could result in a milliwatt or more, which would be enough power to operate many small electrical devices, including sensors and microprocessors. By combining energy-scavenging technology with super-capacitors and cycled operation, the researchers think they can power devices requiring more than 50 milliwatts.


China Unveils Another Supercomputer--But Not Its Fastest
IDG News Service (07/11/11) Michael Kan

China recently launched its newest supercomputer, known as the Tianhe-1 system, using the same technology that it used to build the Tianhe-1A system. The new Tianhe-1 system has a theoretical peak speed of 1.1 petaflops, which is considerably slower than the Tianhe-1A's theoretical peak speed of 4.7 petaflops and a sustained performance of 2.5 petaflops. However, the new system gives China 61 supercomputers in the Top500 list, up from 24 at this time last year. The United States currently has 255 supercomputers on the list. The Tianhe-1A had held the title of world's fastest supercomputer until last month when the Japanese-built K computer took the top spot with a speed of 8.16 petaflops. The new Tianhe-1 system will be used to perform simulations that will forecast the weather, help with disaster prevention, and aid industrial fields such as automobile manufacturing and medical research. By October 2011, the system will have a theoretical peak speed of three petaflops, which could make it the fifth fastest supercomputer in the world, according to China's National University of Defense Technology professor Lu Yutong.


Protecting Protestors With Photos That Never Existed
New Scientist (07/07/11) Paul Marks

In a response to protestors getting arrested for taking pictures of government-instigated violence, researchers at the Indraprastha Institute of Information Technology (IIIT) and the University of Luxembourg have developed a method that uses graphics processors to artificially create photos taken from a perspective where there was no photographer. "We use a computer-vision technique called view synthesis to combine two or more photographs to create another very realistic-looking one that looks like it was taken from an arbitrary viewpoint," says IIIT's Shishir Nagaraja, who worked with Luxembourg researchers Peter Schaffer and Djamila Aouada. The technique involves collecting several images of an event and combining them using software that creates a three-dimensional depth map of the scene. The user chooses an arbitrary viewing angle for a photo they want to post online and the software makes adjustments to the photo, straightening warped lines to give the correct point of view, Schaffer says. "Anonymizing the photographer could be a crucial step in protecting the source of contentious material," says the University of Bern's Matthias Zwicker.
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Chips Hold the Key to Understanding the Human Brain
University of Manchester (07/06/11) Daniel Cochlin

University of Manchester researchers have developed the Spiking Neural Network architecture (SpiNNaker), a computer designed to help scientists understand complex brain injuries, diseases, and conditions. The SpiNNaker system uses chips based on ARM processor technology that have been linked together to simulate the human brain. The system models spikes in electrical signals that are produced by neurons in the brain. Each spike is modeled as a packet of data, which is then sent to all of the connected neurons, represented by small equations that are solved in real time by software running on the ARM processors. SpiNNaker can solve the equations much quicker than biological connections in the brain, enabling the system to process the same amount of information with many fewer connections. The system initially used test chips, but the researchers recently received full chips, which will enable them to develop larger systems that can model the brain. "We hope the machine will be able to model important functions of the human brain and help us gain key insights into their principles of operation," says Manchester professor Steve Furber.


You Are What You Tweet: Tracking Public Health Trends From Twitter Messages
Johns Hopkins University (07/06/11) Phil Sneiderman

Johns Hopkins University researchers have developed software that can track public health trends using Twitter feeds. Researchers Mark Dredze and Michael J. Paul analyzed 2 billion tweets posted between May 2009 and October 2010 and used software to filter out the 1.5 million messages that referenced public health issues. The software disregards tweets that do not relate directly to a user's health, even if it contains a word commonly used in a health context. In about 200,000 of the health-related tweets, the researchers were able to draw on user-provided public information to identify the geographic state from which the message was sent, enabling them to track some trends by time and place, such as when the allergy and flu seasons peaked in various parts of the country. "Our goal was to find out whether Twitter posts could be a useful source of public health information," Dredze says. "In some cases, we probably learned some things that even the tweeters' doctors were not aware of, like which over-the-counter medicines the posters were using to treat their symptoms at home." The researchers say that future studies of tweets could uncover even more useful data, not only about posters' medical problems but also about public perceptions concerning illnesses, medications, and other health issues.


Old Dominion U. Researchers Ask How Much of the Web Is Archived
Chronicle of Higher Education (07/06/11) Jie Jenny Zou

Old Dominion University researchers, led by professor Michael L. Nelson, are trying to determine how much of the public Web is archived and where it is being stored to preserve the digital record. The researchers used Memento, a browser plug-in developed in 2009 to find old versions of different Web pages, to study sites that had been archived using uniform-resource identifiers (URIs). The URIs were compiled from sources such as Google, Bing, Yahoo!, the Open Directory Project, Delicious, and Bitly. The researchers found that up to 90 percent of the Web pages have at least one archived copy. "It's such a moving target--the Web is expanding all the time," says the Internet Archive's Alexis Rossi. "People are coming to the realization that if nobody saves the Internet, their work will just be gone." Nelson says the study is a step toward creating a browsing experience that links the past to the present, enabling users to replay events as they unfolded. "You relive the experience in a way that a summary page can't even begin to capture," Nelson says.
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A Futures Market for Computer Security
Technology Review (07/05/11) Brian Krebs

A pilot prediction market that can forecast major information security incidents before they occur is under development by information security researchers from academia, industry, and the U.S. intelligence community for the purpose of supplying actionable data, says Greg Shannon with Carnegie Mellon University's Software Engineering Institute. "If you're Verizon, and you're trying to pre-position resources, you might want to have some visibility over the horizon about the projected prevalence of mobile malware," he says. "That's something they'd like to have an informed opinion about by leveraging the wisdom of the security community." Consensus Point CEO Linda Rebrovick says the project's objective is to draw a network of approximately 250 experts. Prediction markets have a substantial inherent bias--respondents to questions are not surveyed randomly—but there also is an incentive for respondents to respond only to those queries they feel confident in answering accurately. "People tend to speak up only when they're reasonably sure they know the answer," says Consensus Point chief scientist Robin Hanson. Even lukewarm responses to questions can be useful, notes Dan Geer, chief information security officer at the U.S. Central Intelligence Agency's In-Q-Tel venture capital branch.


Firefox PDF Reader Passes 'Pixel-Perfect' Test
CNet (07/04/11) Stephen Shankland

Mozilla programmers have used Web programming technology to build pdf.js, a PDF reader that offers pixel-perfect rendering of a particular file containing formatted text, graphics, tables, and graphical diagrams. Mozilla programmers Andreas Gal and Chris Jones say pdf.js is mature enough to warrant the 0.2 version number. The programmers introduced the pdf.js project, which uses JavaScript and HTML5's Canvas For to process and display the file, in June, and the new version offers a better user interface, support for TrueType fonts, and improved graphics abilities, among other features. The team wants pdf.js to work in all HTML5-compliant browsers. "And that, by definition, means pdf.js should work equally well on all operating systems that those browsers run on," Gal and Jones say. Mozilla plans to include the software in Firefox. "We would love to see it embedded in other browsers or Web applications; because it's written only in standards-compliant Web technologies, the code will run in any compliant browser," the programmers note.


Can Anyone Create a Hacker-Proof Cyberspace?
Knowledge@Wharton (07/06/11)

The opportunity for cyberattacks increases every day as corporations and governments continue stockpiling information about individuals in complex networks across the Internet, while new generations of cybercrooks continue to hack into private data, according to faculty and security analysts at the University of Pennsylvania's Wharton School. The administration's proposal stresses consumer protection via a standardized federal mandate for reporting data breaches to replace the current hodgepodge of state laws. The proposal also would make federal Racketeering Influenced and Corrupt Organizations Act penalties applicable to cybercrime. In addition, the White House would collaborate with the private sector to enhance the security of critical infrastructure and upgrade security of the federal government's computer systems. Wharton professor Shawndra Hill says the best strategy for fighting threats to national security is through a consortium of government, industry, and academia, with technical experts being allowed to inform legislators on what is possible with respect to cyberthreats and vice versa. Wharton professor Eric Bradlow notes that academics, statisticians, and computer scientists are devising new approaches to organizing data that can provide much of the advantage of individual-level data with considerably less risk.


Mind-Controlled
Science News (07/02/11) Susan Gaidos

Brain-computer interfaces have enabled patients to execute basic thought-controlled tasks in the lab, but researchers say the technology is close to enabling people to carry out simple everyday tasks, such as tying shoes and pulling zippers. Current designs for monitoring the electrical firings of single motor cortex neurons constitute electrode arrays implanted in the brain, linked to a computer that decodes recorded neural signals to move a cursor on the screen, or even a robotic limb. However, over the next few years, paralysis patients will attempt to learn how to manipulate virtual hands or robotic appendages to reach, push, grasp, or eat, and researchers hope to train users to carry out movements of increasing complexity as the trials progress. Some brain-computer interfaces attempt to capture electrical signals using grids of electrodes on the surface of the dura mater, rather than implanting electrodes within the brain itself. The electrode grids can pick up the signals of neuron groups, and these neural assembles have synchronized activity that generates local field potentials, broadcasting what the brain is doing. The assemblies can adjust themselves to signal for particular movements through training.


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