Smartphone Accelerometers Distinguish Between Different Motorized Transportation Modalities
Science Daily November 13, 2013
Identifying the individual’s transportation behavior is a fundamental problem, as it reveals information about the user’s physical activity, personal CO2 -footprint and preferred transit type. On a larger scale, this information could be aggregated to discover information about the utilization of different transportation options to aid urban planning.
Researchers from the University of Helsinki have developed methods for extracting information about vehicular movement patterns from measurements of a smartphone accelerometer. The key idea is to extract characteristic acceleration and breaking patterns and to use these as a kind of signature to separate between different vehicular transportation modes.
The main researcher, Samuli Hemminki, explains: “Extracting vehicular movement information from smartphone accelerometers is challenging as the placement of the device can vary, users interact with the phone spontaneously, and as the orientation of the phone can change dynamically. We overcame these challenges by developing novel algorithms for processing and analyzing accelerometer measurements.”
Experimental evaluations demonstrate that the technique can detect most common public transportation types (bus, tram, metro, train, car, walking) with over 80 per cent accuracy. The benefits of the method are particularly pronounced in daily monitoring as the system has low power consumption and works robustly in continuous detection tasks.
Dr. Petteri Nurmi from University of Helsinki adds: “Our work enables fine-grained modeling of human transportation behavior and serves as an important building block for new kinds of mobile applications. For example, our methods would be beneficial to an application that provides feedback to encourage drivers towards more ecological driving style or to map deviations in public transportation.”
Professor Sasu Tarkoma explains: “This research shows that it is possible to accurately detect the transportation mode on smartphones in an energy efficient manner. The system enables a whole new breed of mobility-aware applications and services.”
Creating Accountable Anonymity Online: Systems That Currently Allow Users Complete Anonymity Are Being Abused
Science Daily November 7, 2013
The World Wide Web is, in many ways, still the Wild West. Though a large portion of internet traffic is monitored and traceable, systems like the Tor Project allow users to post and share anything anonymously. Anonymous systems provide enormous public benefits by helping journalists, activists, and others communicate in private, away from the prying eyes of the Internet at-large.
These systems, however, have been degraded by criminals who use them to support unlawful activities. Tor reportedly has been used to aid in the selling of illegal drugs and in the proliferation of child pornography, among other crimes. With complete anonymity, criminals are often free to do whatever they like with little or no repercussions.
Researchers at Iowa State University are working to solve this problem with an approach they call accountable anonymity. Yong Guan, an associate professor of electrical and computer engineering, and his students, have devised a system that offers anonymity for honest users, and accountability for dishonest users.
“The lack of accountability on these anonymous services is easy to exploit,” Guan says. “Criminals use anonymous systems to commit crimes against innocent people online and in the real world. I thought there was a real need for accountability within these systems to protect honest users that just wish to exchange lawful information anonymously.”
Tor works by sending information through a series of nodes and using layers of encryption at each stop. When the information arrives at its destination, the encrypted messages are unlocked with a key and the original message becomes readable. The layers of encryption disguise the origin of the message, thus providing anonymity, but at a high computing cost. Bouncing messages around a network, and adding a layer of encryption with each bounce, takes time and computing power. If a criminal uses the service to send a malicious message, the network expends the same computing power to send that message, and the victim has limited ways to trace it.
Guan’s system, named THEMIS, is designed to minimize the computing power used to send messages and provide a way to track the source of the message, should it be thought of as malicious. By its very design, the system avoids expending computing power to send illegal and harmful messages.
“With a level of accountability, criminal activity online will decrease,” Guan says. “By that measurement, computing power expended to support criminal activity will also decrease. That’s a good thing.”
The system aims to offer four features:
First and foremost, the system must provide anonymity under normal circumstances. Users looking to exchange information in a lawful manner without being tracked will be able to do so without problems.
“Providing reliable anonymity is the first step,” Guan says. “Without it, users won’t use the system.”
Second, the system must, under certain circumstances, allow for the identification of sources without impairing other users’ anonymity. This involves a number of steps, including notifying law enforcement. This feature would be used to find senders of malicious messages, and requires the cooperation of the system’s key generator and internet service provider’s registration database.
“Our system provides law enforcement with the means to catch criminals who wish to distribute illegal or harmful messages,” Guan says. “Without some kind of accountability, users tend to show an absence of restraint.”
Third, the system must be incentive compatible. This means users must have an incentive to use the system as it is intended to be used. Without incentive compatibility, users can simply bypass attributes of the system they don’t wish to comply with.
Fourth, the system must make framing or impersonating an honest user impossible. THEMIS achieves this by using digital signatures that are computationally infeasible to generate without source keys.
“Forging keys is computationally difficult,” Guan says. “If a node wishes to obtain a signing key, or sign a message without the source’s signing key, it would have to solve a problem that is incredibly difficult, even for the fastest computers.”
THEMIS is composed of two separate proxy re-encryption based schemes. Scheme one, a multi-hop proxy re-encryption-based scheme, provides an anonymous communication channel between the source of a message and its destination. Much like with Tor, messages in THEMIS are bounced through several proxies. However, instead of adding layers of encryption, THEMIS converts the original message at each stop using XAG encryption. Each proxy along the path knows only its predecessor and successor, and proxy re-encryption keys to corresponding channels are hidden in the message in an onion header. The layers of the onion header contain the information for the corresponding node.
Scheme two provides for accountability when malicious messages are present. As with any encryption system, public keys and private keys are utilized to ensure that messages arrive where they should and are readable to the intended recipient. However, an AFGH re-encryption key is included with each message and serves as the accountability information which links the destination of the message to its source. Without this AFGH re-encryption key, messages are unreadable.
At the request of the message recipient, law enforcement officials can use the AFGH re-encryption key to track the source of the message. Law enforcement can subpoena data from the key generator and the internet service provider’s registration database and use this data with the message’s AFGH re-encryption key to determine the source of the message.
“If no one reports the message as malicious,” Guan says, “law enforcement cannot get involved. There would be no way for them to know about it.”
Guan envisions his system as a way for law enforcement to track down senders of threatening emails and those who leak important documents. THEMIS represents the first system to provide both anonymity and accountability in an incentive-compatible fashion and the first anonymous network to use multi-hop proxy re-encryption.
“The next step,” Guan says, “is to test it on a large scale over the Internet. This way, we can really see how well it performs.”
Highly Anticipated Dark Matter Update Expected Next Week
The influential Large Underground Xenon experiment, a dark matter detector based in South Dakota, is set to release its first results
Scientific American by Eugenie Samuel Reich & Nature magazine October 23, 2013
Viewed end on, the arrays of photomultiplier tubes on the Large Underground Xenon (LUX) experiment look like beds of flowers. The hope is that they will capture sparks of light emitted when particles of dark matter collide with liquid xenon.With 122 detector tubes, LUX is much more sensitive than its closest rival in the competitive field of dark-matter searches — and in just days, physicists the world over will know whether that advantage has yielded definitive results.
The project, based at the Sanford Underground Research Facility in Lead, South Dakota, will release its first findings on 30 October. They are likely to reveal whether tentative dark-matter signals seen by other experiments are real, and will also inform ongoing discussions about how much more time and money should be spent on the hunt for dark matter. “The potential is there, and all the community is waiting with bated breath to see what they observe,” says Juan Collar, a physicist who leads a rival experiment at the University of Chicago in Illinois.
Elena Aprile, a physicist at Columbia University in New York city who leads another competitor, XENON100, based at Gran Sasso National Laboratory near L’Aquila, Italy, is betting that LUX has not seen dark matter. “A null result is all that can be expected at this stage,” she says. A LUX spokesman, physicist Daniel McKinsey of Yale University in New Haven, Connecticut, says simply: “We have a detector that is working very, very well.”
LUX came online this year amid fierce debate. Scientists know from astronomical observations that five-sixths of the matter in the Universe is dark — making itself known mostly through its gravitational tug on bright matter — but attempts to detect it directly, on its presumed passage through Earth, have been fraught with controversy.
The DAMA/LIBRA experiment (Dark Matter Large Sodium Iodide Bulk for Rare Processes) at Gran Sasso reported a statistically significant signal more than 10 years ago, but physicists have not independently confirmed the result. In 2010, the Coherent Germanium Neutrino Technology experiment in Soudan, Minnesota, and the Cryogenic Dark Matter Search at the University of California, Berkeley, each reported tantalizing, but not statistically convincing, glimpses of potential dark matter; a year later, XENON100 saw no sign of the stuff. That prompted heated discussion over whether the experiment was sensitive to the lighter dark-matter particles that might have been glimpsed by the other two experiments.
Enter LUX, which will deliver its first results just as the US Department of Energy decides which of several dark-matter experiments should be given money to expand. LUX wants to install a larger, 7-metric ton detector, in a proposed US$30-million project called LUX–Zeplin. McKinsey argues that such experiments should be scaled up until they hit a physical limit — when the background noise from other weakly interacting particles becomes overwhelming. “That’s a natural break point,” agrees Jonathan Feng, a theoretical physicist at the University of California, Irvine.
One candidate for dark matter is the neutralino, a particle predicted by some super symmetric theories of particle physics, in which particles are paired with heavier counterparts. If, as Feng expects, LUX sets a detection threshold around three times more stringent than that of XENON100, it will rule out the neutralino and shift theoretical effort to other candidates. “There’s an unbelievable amount of effort focused on the neutralino, so this upcoming announcement is quite important,” he says.
Shanghai prof claims Li-Fi advance, prepares show kits
PHYS-ORG by Nancy Owano October 21, 2013
Scientists say “Li-Fi,” Wi-fi connectivity from a light bulb, is making new advancements. Chi Nan, information technology professor at Shanghai’s Fudan University, at work with a research team of scientists from Shanghai Institute of Technical Physics at the Chinese Academy of Sciences, spoke to the official news agency Xinhua about the progress. The news, posted on October 17, is that a microchipped bulb can produce data speeds of up to 150 megabits per second (Mbps), which is faster than the average broadband connection in China. She said it would take only a one-watt light emitting diode (LED) lightbulb to connect four computers to the Internet, based on the principle that light can be used as a carrier instead of traditional radio frequencies. Her team hopes to present Li-Fi kits at the China International Industry Fair, an event that focuses on new industries, in Shanghai next month. Those advancements are to be taken within reason that the technology, she said, remains in its infancy; microchip design and optical communication controls would need more attention before there is any conversation about mass-market Li-Fi.
Data rates as fast as 150 megabits per second were achieved with the new Li-Fi connection, according to the Xinhua report, which was headlined “Chinese scientists achieve Internet access through lightbulbs” and announced that the scientists’ experiments “indicated the possibility of the country’s netizens getting online through signals sent by lightbulbs (LiFi), instead of WiFi.” Chinese people are replacing the old-fashioned incandescent bulbs with LED lightbulbs at a fast pace, said the agency.To be sure, many observers recognize that, in theory, this would be a step forward as a cheaper and more efficient means of connectivity than wireless radio systems, given that LED bulbs are expected to become dominant over the next 20 years, and the lighting infrastructure is already in place. By altering the length of the flickers, scientists have explored the possibility of sending digital information to adapted PCs and other electronic devices.
Li-Fi is a term referring to “light fidelity” coined by Prof. Harald Haas from the University of Edinburgh and refers to a type of visible light communication (VLC) technology that delivers a networked, mobile, high-speed communication solution. He set up a private company, PureVLC, to continue exploring the technology. As for reactions to the report from China, a spokesperson, according to the BBC, said they thus far had not seen any evidence such as videos or photos in support of the claims. PureVLC spokesman Nikola Serafimovski said they did not know how valid was the report “without seeing more evidence.”
In 2011, Haas demonstrated how an LED bulb equipped with signal processing technology could stream a high-definition video to a computer. Haas performed the first public demonstration of visible light communications live at TED Global, where he showed an angle poise lamp fitted with an LED bulb transmitting high-definition video displayed on a screen. When he interrupted the light with his hand, the video froze and it was then restored when he removed his hand.
Direct Link: http://phys.org/news/2013-10-shanghai-prof-li-fi-advance-kits.html
Microsoft pulled the RT 8.1 update some time in the morning of October 19, as reported by WinBeta.org, two days after it first made it available for download by existing Windows RT users.
I asked Microsoft what led to the decision to pull the update and received the following statement from a spokesperson:
“Microsoft is investigating a situation affecting a limited number of users updating their Windows RT devices to Windows RT 8.1. As a result, we have temporarily removed the Windows RT 8.1 update from the Windows Store. We are working to resolve the situation as quickly as possible and apologize for any inconvenience. We will provide updates as they become available.” I managed to update my Surface RT to Windows RT 8.1 on October 17 after several attempts to get the device to find the update. I have heard from a number of other Windows RT users who’ve had similar difficulties in locating and getting the update process to begin on their ARM-based Microsoft-made and OEM devices.
Microsoft made available for download the Windows 8.1 (for Intel) and Windows RT 8.1 (for ARM) updates earlier this week. Windows 8.1 adds a Start Button, boot-to-desktop option and other updates designed to improve the usability and appeal of Windows 8.
Microsoft is going to make its next-generation Surface devices running Windows 8.1 — the ARM-based Surface 2 and the Intel-based Surface 2 Pro — available for purchase on October 22.
Update: Microsoft has posted a Surface RT recovery image to the Microsoft Download Center. I’m assuming this is meant to help those who’ve had problems installing Windows RT 8.1 and/or bricked their Surface RTs attempting to update to Windows RT 8.1. Still no word from officials as to when the company plans to make Windows RT 8.1 available in the Store again.