Voting for more than just either-or

Traditional voting systems only allow people to make a single choice -- a limitation many voters find frustrating, particularly when there is a crowded field of candidates as there was early in the current presidential nominating cycle.

But it doesn't have to be that way.

Alternative voting systems, which allow people to rank their preferences in order instead of simply picking one, have been known for centuries, but have been devilishly difficult to implement and often result in a very slow tallying of results. One example is the system used in the Iowa caucuses, in which supporters of candidates who fail to reach a certain threshold in the first round can then move on to their second choices, and so on until a clear winner emerges.

A new computer software system developed by MIT researchers promises to make such ranking systems just as easy as traditional voting -- and to give results that leave more people satisfied. The system is about to get its first mass-market trial with the cable music network MTV.

Benjamin Mako Hill, while he was a graduate student in the MIT Media Lab's Computing Culture group, created a system called Selectricity, which has been online as a free service since last fall and is about to unveil an upgraded version with more options. With this software, any user can go to the website (www.selectricity.org) and set up a "Quickvote" in just a few seconds, and users anywhere who have access to the Internet can then cast their votes, providing an instant tally.

There's even an ultra-simple version that works through cellphones using basic text messaging. The system is so simple that hundreds of people have been using it for decisions as simple and immediate as where to go for dinner or when to hold a meeting.

But the system is also sophisticated enough to handle real elections, at least on a small scale. In February, a beta version of the new, improved software was used by a national student organization to elect their first board of directors -- and the way that election turned out was a dramatic confirmation of the value of the new system.

Each of 16 campus chapters of the group Students for Free Culture got an equal vote to select five members of their governing board from among a slate of 13 candidates. But as it turned out, the result would have been very different had they used a traditional voting system.

Hill, now a research fellow at MIT's new Center for Future Civic Media, says "the first place winner in plurality didn't even make it into the top five" using the more sophisticated preferential voting system, in which each chapter was able to rank all of the candidates in order of preference. That candidate, who would have been the winner in an ordinary election, "was ranked first more than any other candidate" -- four first-place votes out of 16 -- but "he was very polarizing and was ranked near-last on most of the other ballots," Hill explains. So in a traditional vote, the vast majority of the voters would have been very unhappy with the outcome.

Instead, with the Selectricity preferential voting system -- which allows the results to be scored using any of a variety of different known mathematical systems for selecting winners -- "the first-place winner using the Schulze/Condorcet (and most of the other methods) had only two first-place votes, but was in the top three or four on almost every ballot," Hill says. "It ended up being a real example of the power of preferential elections," leaving a majority of voters satisfied.

Selectricity users can pick which selection method to use when they set up a ballot, but once votes are cast the website also allows users the option of analyzing the results using several alternative methods, so that the outcomes can be compared.

The five methods currently included are:

• A traditional simple plurality method: whoever gets the most first-place votes wins.
• The "Approval" method, devised in the 1970s, in which people can vote "for" as many candidates as they like -- one vote per candidate -- to indicate which ones would be acceptable, and then all the votes for each candidate are simply added up and the person with the most votes wins.
• The Borda count, first proposed in 1770, which awards weighted numbers to each candidate depending on the ranking voters give them (such as 1 for a first-place vote, 2 for second, etc.) and then these numbers are totaled to determine the winner.
• The Condorcet method, devised in 1299 and refined in the 18th century, in which each candidate is compared one at a time with each of the others to see which one was preferred over the other by the most people, and then the one who wins the most of these pairings is the winner.
• The Schulze methode, a refinement of Condorcet devised in 1997, which uses a complex mathematical formula to compare each candidate's rankings with each of the others.

MTV, which provided Hill with a $30,000 grant for the project last year as a winner of its mtvU "Digital Incubator" competition, is planning to use Selectricity to allow viewers to vote for their preferences among a selection of music videos to be presented in a new program that will be airing in the next few weeks. Details are still being worked out with the network, Hill says.

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Microchip fingerprints used to lock out chip pirates

Pirated microchips -- chips stolen from legitimate factories or made from stolen blueprints -- account for billions of dollars in annual losses to chipmakers.

But a series of novel techniques developed at Rice University over the past year could stop pirates by allowing chip designers to lock and remotely activate chips with a unique ID tag. When a chip is locked with the new technology, only the patent-holder can decipher the key and activate the chip -- meaning knockoffs and stolen chips are worthless.

"Ours is the first remote-activation scheme that protects integrated circuits against piracy by exploiting their inherent, unclonable variability," said the technology's original inventor, Farinaz Koushanfar, assistant professor in electrical and computer engineering at Rice. "We use slight variations that arise in modern manufacturing to create a unique, digital identification that acts like a fingerprint for each chip, and we integrate that into the chip's functionality."

The original work was presented last August at the USENIX Security Symposium in Boston. Since the invention of the method, Koushanfar has collaborated with a number of researchers to build upon her original scheme. Last October, at the International Conference in Computer Aided Designs, Koushanfar and Rice graduate student Yousra Alkabani, in collaboration with Miodrag Potkonjak from UCLA, showed the first method that could continuously check, control, enable and disable a chip's operation online by integrating the chip's fingerprints into its functionality and actively checking them during operation.

This month, Koushanfar and colleagues at the University of Michigan, Igor Markov and Jarrod Roy, unveiled a new form of the technology called “EPIC: Ending Piracy of Integrated Circuits" at the IEEE Design Automation and Test Conference in Europe. The latest method is based on public key cryptography and works for chips that already have a built-in cryptography module. In all tests and research published during the past year, the new technology has proven to be stable, unclonable and attack-resilient.

"The public tends to overlook hardware piracy and focus instead on the well-known and oft-publicized problem of software piracy," Koushanfar said. "But some intellectual-property experts who have studied both estimate that the economic losses from hardware piracy is more severe compared to software piracy."

Hardware piracy has become increasingly problematic as the skyrocketing costs of microchip production have led chip-design companies to get out of the manufacturing business. When design and manufacturing are done by different companies, the design company's sole asset is the intellectual property (IP) associated with the integrated circuit's (IP) blueprints.

Hardware makers have tried a number of approaches to safeguard designers' IP, including stamping chips with watermarks, registering legitimate chips in databases and requiring the one-time use of an ID to unlock a chip's functionality. But safeguarding individual ICs – and not IPs – is the unique aspect and contribution of Koushanfar’s work.

Koushanfar said her original technology and her subsequent collaborative work stand apart from previously tried schemes because the ID generated in her scheme is derived directly from the chip itself, and without the ID, the chip will not function.

"The chip itself provides the key," she said. "There is no way to steal it because it doesn't exist until the chip is actually made, and once made, only the designer knows how to decipher the key."

For her original invention, Koushanfar has received the Defense Advanced Research Projects Agency (DARPA) Young Faculty Award last year. Both the National Science Foundation and DARPA presently fund Koushanfar’s research. Koushanfar is also the director of the Texas Instruments DSP Leadership University program at Rice and has close industrial-level collaborations on her hardware security projects.

Via

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MIT develops energy-efficient microchip

Researchers at MIT and Texas Instruments have unveiled a new chip design for portable electronics that can be up to 10 times more energy-efficient than present technology. The design could lead to cell phones, implantable medical devices and sensors that last far longer when running from a battery.

The innovative design will be presented Feb. 5 at the International Solid-State Circuits Conference in San Francisco by Joyce Kwong, a graduate student in MIT's Department of Electrical Engineering and Computer Science (EECS).

Kwong carried out the project with MIT colleagues Anantha Chandrakasan, the Joseph F. and Nancy P. Keithley Professor of Electrical Engineering, and EECS graduate students Yogesh Ramadass and Naveen Verma. Their Texas Instruments (TI) collaborators are Markus Koesler, Korbinian Huber and Hans Moormann. The team demonstrated the ultra-low-power design techniques on TI's MSP430, a widely used microcontroller. The work was conducted at the MIT Microsystems Technology Laboratories, which Chandrakasan directs.

The key to the improvement in energy efficiency was to find ways of making the circuits on the chip work at a voltage level much lower than usual, Chandrakasan explains. While most current chips operate at around one volt, the new design works at just 0.3 volts.

Reducing the operating voltage, however, is not as simple as it might sound, because existing microchips have been optimized for many years to operate at the higher standard-voltage level. “Memory and logic circuits have to be redesigned to operate at very low power supply voltages,” Chandrakasan says.

One key to the new design, he says, was to build a high-efficiency DC-to-DC converter-which reduces the voltage to the lower level-right on the same chip, reducing the number of separate components. The redesigned memory and logic, along with the DC-to-DC converter, are all integrated to realize a complete system-on-a-chip solution.

One of the biggest problems the team had to overcome was the variability that occurs in typical chip manufacturing. At lower voltage levels, variations and imperfections in the silicon chip become more problematic. “Designing the chip to minimize its vulnerability to such variations is a big part of our strategy,” Chandrakasan says.

So far the new chip is a proof of concept. Commercial applications could become available “in five years, maybe even sooner, in a number of exciting areas,” Chandrakasan says. For example, portable and implantable medical devices, portable communications devices and networking devices could be based on such chips, and thus have greatly increased operating times. There may also be a variety of military applications in the production of tiny, self-contained sensor networks that could be dispersed in a battlefield.

In some applications, such as implantable medical devices, the goal is to make the power requirements so low that they could be powered by “ambient energy,” Chandrakasan says-using the body's own heat or movement to provide all the needed power. In addition, the technology could be suitable for body area networks or wirelessly enabled body sensor networks.

“Together, TI and MIT have pioneered many advances that lower power in electronic devices, and we are proud to be part of this revolutionary, world-class university research,” said Dr. Dennis Buss, chief scientist at Texas Instruments. “These design techniques show great potential for TI future low-power integrated circuit products and applications including wireless terminals, battery-operated instrumentation, sensor networks and medical electronics.”

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Computer learns dogspeak

Computer programs may be the most accurate tool for studying acoustic communications amongst animals, according to Csaba Molnár from Eötvös Loránd University in Hungary and his research team. Their paper, published in Springer’s journal Animal Cognition this week, shows that a new piece of software is able to classify dog barks according to different situations and even identify barks from individual dogs, a task humans find challenging.

The aim of Molnár and colleagues’ experiments was to test a computer algorithm’s ability to identify and differentiate the acoustic features of dog barks, and classify them according to different contexts and individual dogs. The software analyzed more than 6000 barks from 14 Hungarian sheepdogs (Mudi breed) in six different situations: ‘stranger’, ‘fight’, ‘walk’, ‘alone’, ‘ball’ and ‘play’. The barks were recorded with a tape recorder before being transferred to the computer, where they were digitalized and individual bark sounds were coded, classified and evaluated.

In the first experiment looking at classification of barks into different situations, the software correctly classified the barks in 43 percent of cases. The best recognition rates were achieved for ‘fight’ and ‘stranger’ contexts, and the poorest rate was achieved when categorizing ‘play’ barks. These findings suggest that the different motivational states of dogs in aggressive, friendly or submissive contexts may result in acoustically different barks.

In the second experiment looking at the recognition of individual dogs, the algorithm correctly classified the barks in 52 percent of cases. The software could reliably discriminate among individual dogs while humans can not, which suggests that there are individual differences in barks of dogs even though humans are not able to recognise them.

The authors conclude by highlighting the value of their new methodology: “The use of advanced machine learning algorithms to classify and analyze animal sounds opens new perspectives for the understanding of animal communication… The promising results obtained strongly suggest that advanced machine learning approaches deserve to be considered as a new relevant tool for ethology*.”

* Ethology: the study of animal behavior, with a focus on behavioral patterns in natural environments.

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SETI@home ramps up to analyze more data

The longest-running search for radio signals from alien civilizations is getting a burst of new data from an upgraded Arecibo telescope, which means the SETI@home project needs more desktop computers to help crunch the data.

Since SETI@home launched eight years ago, the project based at the University of California, Berkeley's Space Sciences Laboratory has signed up more than 5 million interested volunteers and boasts the largest community of dedicated users of any Internet computing project: 170,000 devotees on 320,000 computers.

Yet, new and more sensitive receivers on the world's largest radio telescope in Arecibo, Puerto Rico, and better frequency coverage are generating 500 times more data for the project than before.The SETI@home software has been upgraded to deal with this new data as the search for extraterrestrial intelligence (SETI) enters a new era and offers a new opportunity for those who want to help find other civilizations in the universe.

"The next generation SETI@home is 500 times more powerful then anything anyone has done before," said project chief scientist Dan Werthimer. "That means we are 500 times more likely to find ET than with the original SETI@home."

According to project scientist Eric Korpela, the new data amounts to 300 gigabytes per day, or 100 terabytes (100,000 gigabytes) per year, about the amount of data stored in the U.S. Library of Congress. "That's why we need all the volunteers," he said. "Everyone has a chance to be part of the largest public participation science project in history."

The 1,000-foot diameter Arecibo dish, which fills a valley in Puerto Rico, is part of the National Astronomy and Ionosphere Center operated by Cornell University with funds from the National Science Foundation. Since 1992, Werthimer and his team have piggybacked on radio astronomy observations at Arecibo to record signals from space and analyze them for patterns that could indicate they were transmitted by an intelligent civilization.

When the team's incoming data overwhelmed its ability to analyze it, the scientists conceived a distributed computing project to harness many computers into one big supercomputer to do the analysis. Since SETI@home was launched, other distributed computing projects have arisen, from folding@home to predict the three-dimensional tangle of a protein to the newly-launched cosmology@home to model possible universes. Most are now on a platform called BOINC (Berkeley Open Infrastructure for Network Computing), which was developed by SETI@home's director David Anderson so that the various projects could share resources.

"There are now 42 projects on BOINC, and, until now, there has been enough computing power to go around," Werthimer said.

What triggered the new flow of data was the addition of seven new receivers at Arecibo, which now allow the telescope to record radio signals from seven regions of the sky simultaneously instead of just one. With greater sensitivity and the ability to detect the polarization of the radio signals, plus 40 times more frequency coverage, Arecibo is set to survey the sky for new radio sources.

These improvements also prime the telescope for an improved search for intelligent signals from space.

"The multiple receivers help us weed out interference better and make us less susceptible to thinking that things terrestrial are extraterrestrial," Werthimer said.

Werthimer noted that, despite the fact that UC Berkeley has been analyzing radio signals from space since 1978 on various telescopes, no telltale signals from an intelligent civilization have yet been found.

"Earthlings are just getting started looking at the frequencies in the sky; we're looking only at the cosmically brightest sources, hoping we are scanning the right radio channels," he said. "The good news is, we're entering an era when we will be able to scan billions of channels. Arecibo is now optimized for this kind of search, so if there are signals out there, we or our volunteers will find them."

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Sshhh, it’s listening: totally new computer interfaces

Keyboards are a necessary part of today’s computers, right? Maybe not for much longer. A group of European scientists have used acoustic sensors to turn wooden tabletops and even three-dimensional objects into a new type of computer interface.

Sound vibrating a windowpane or through a tabletop is something most people experience daily. Sound waves travel well through most solid materials. Now, European researchers have exploited the excellent propagation of sound waves through solids to turn everyday objects – including 3D objects – into a new kind of computer interface.

By attaching sensors to solid materials, researchers from TAI-CHI, a project working with Tangible Acoustic Interfaces for Computer-Human Interaction, were able to locate exactly and track acoustic vibrations. Tapping on discrete areas of a whiteboard could generate musical notes on a computer. Tracking the sound of a finger scrawling words on a sheet of hardboard could translate, in real time, into handwriting on a computer screen. There is no need for overlays or intrusive devices.

Sensing vibrations in a solid and converting them to electrical pulses is the easy bit. Exactly locating the source of that vibration in a solid material is where it gets complicated. The problem is that the complex structures of solids make wave propagation difficult to model. Wood knots in a desktop, for instance, will alter how acoustic vibrations disperse.

Reading the signals

The TAI-CHI team investigated four main technologies. Time Delay of Arrival (TDOA) uses three or more sensors and compares the difference in arrival times of an acoustic wave at each of the sensors to establish location. In fact, the concept of TDOA has been around for about 100 years. Provided you know the propagation velocity of acoustic waves through the solid material, TDOA provides a very practical, if rather expensive, solution.

Time reversal, on the other hand, needs only a single sensor. It works on the notion that each location on the surface of a solid generates a unique impulse response which can be recorded and used to calibrate the object. Time reversal works on 3D objects just as well as flat surfaces.

MUlti-Sensor Tracking through the Reversal of Dispersion (MUST-RD) requires a deep understanding of the wave-dispersion properties of the solid. The dispersion curve of acoustic waves moving through the material under test is compared to a database of dispersion curves for common materials. From the comparison, the location of the vibration source can be calculated. (MUST-RD can also be used to give a crude estimation of a material type.)

Finally, TAI-CHI researchers worked with in-solid acoustic holography. Using sound pressure, sound intensity or particle velocity to calculate position and time, a sound source can be mapped and visualised in much the same way as an infrared camera can map heat sources. Some of the TAI-CHI researchers also experimented with a combination of acoustic localisation and Doppler tracking to locate and track sound sources moving through the air.

The range of researchers brought together by the project, part-funded by the European Commission – in Germany, France, Italy, England, Wales and Switzerland – was an important factor in its success, according to TAI-CHI coordinator, Dr Ming Yang of the University of Cardiff.

Specialist solution

Tangible acoustic interfaces like this are not going to replace keyboards and computer mice in the near future, says Dr Ming Yang. But in specific environments where keyboards are impractical – perhaps in very dirty environments or in hospitals where a keyboard might be a hiding place for bugs – TAIs could provide an elegant solution.

“Time reversal is a beautiful technology,” he says. “Unlike TDOA, it works with any object and it does not require special materials. Because it needs only a single sensor and a normal computer, it is very simple and cost-effective. One spin-off company from the University of Paris is working on commercial applications for this.”

Other technologies, such as acoustic holography, show great promise but are not ready for commercialisation.

CeTT, a Swiss member of the consortium, has put together a TAI-CHI Developer’s Kit, comprising algorithms developed during the project, software and hardware, as a one-stop-shop for application developers looking to build on TAI-CHI breakthroughs.

Other applications include a wireless sensor using Bluetooth technology that Dr Ming Yang would like to develop with commercial partners.

The time-reverse technology is the project’s major breakthrough, according to Dr Ming Yang. “Before, people were only working on easy materials. We have developed it for metal, plastic and board. We have a really interactive interface.”

SOURCE

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Next-generation, high-performance processor unveiled

The prototype for a revolutionary new general-purpose computer processor, which has the potential of reaching trillions of calculations per second, has been designed and built by a team of computer scientists at The University of Texas at Austin.
The new processor, known as TRIPS (Tera-op, Reliable, Intelligently adaptive Processing System), could be used to accelerate industrial, consumer and scientific computing.
Professors Stephen Keckler, Doug Burger and Kathryn McKinley have been working on underlying technology that culminated in the TRIPS prototype for the past seven years. Their research team designed and built the hardware prototype chips and the software that runs on the chips.
"The TRIPS prototype is the first on a roadmap that will lead to ultra-powerful, flexible processors implemented in nanoscale technologies," said Burger, associate professor of computer sciences.
TRIPS is a demonstration of a new class of processing architectures called Explicit Data Graph Execution (EDGE). Unlike conventional architectures that process one instruction at a time, EDGE can process large blocks of information all at once and more efficiently.
Current "multicore" processing technologies increase speed by adding more processors, which individually may not be any faster than previous processors.
Adding processors shifts the burden of obtaining better performance to software programmers, who must assume the difficult task of rewriting their code to run well on a potentially large number of processors.
"EDGE technology offers an alternative approach when the race to multicore runs out of steam," said Keckler, associate professor of computer sciences.
Each TRIPS chip contains two processing cores, each of which can issue 16 operations per cycle with up to 1,024 instructions in flight simultaneously. Current high-performance processors are typically designed to sustain a maximum execution rate of four operations per cycle.
Though the prototype contains two 16-wide processors per chip, the research team aims to scale this up with further development.
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