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A Magnetic Pen for Smartphones Adds Another Level of Conveniences

A doctoral candidate at the Korea Advanced Institute of Science and Technology (KAIST) developed a magnetically driven pen interface that works both on and around mobile devices. This interface, called the MagPen, can be used for any type of smartphones and tablet computers so long as they have embedded magnetometers.

The animated facial expressions displayed on a smartphone changes to smile as permanent magnets are placed on the phone's screen.

Advised by Professor Kwang-yun Wohn of the Graduate School of Culture Technology (GSCT) at KAIST, Sungjae Hwang, a Ph.D. student, created the MagPen in collaboration with Myung-Wook Ahn, a master's student at the GSCT of KAIST, and Andrea Bianchi, a professor at Sungkyunkwan University.

Almost all mobile devices today provide location-based services, and magnetometers are incorporated in the integrated circuits of smartphones or tablet PCs, functioning as compasses. Taking advantage of built-in magnetometers, Hwang's team came up with a technology that enabled an input tool for mobile devices such as a capacitive stylus pen to interact more sensitively and effectively with the devices' touch screen. Text and command entered by a stylus pen are expressed better on the screen of mobile devices than those done by human fingers.

The MagPen utilizes magnetometers equipped with smartphones, thus there is no need to build an additional sensing panel for a touchscreen as well as circuits, communication modules, or batteries for the pen. With an application installed on smartphones, it senses and analyzes the magnetic field produced by a permanent magnet embedded in a standard capacitive stylus pen.

Sungjae Hwang said, "Our technology is eco-friendly and very affordable because we are able to improve the expressiveness of the stylus pen without requiring additional hardware beyond those already installed on the current mobile devices. The technology allows smartphone users to enjoy added convenience while no wastes generated."

The MagPen detects the direction at which a stylus pen is pointing; selects colors by dragging the pen across smartphone bezel; identifies pens with different magnetic properties; recognizes pen-spinning gestures; and estimates the finger pressure applied to the pen.

Notably, with its spinning motion, the MagPen expands the scope of input gestures recognized by a stylus pen beyond its existing vocabularies of gestures and techniques such as titling, hovering, and varying pressures. The tip of the pen switches from a pointer to an eraser and vice versa when spinning. Or, it can choose the thickness of the lines drawn on a screen by spinning."It's quite remarkable to see that the MagPen can understand spinning motion. It's like the pen changes its living environment from two dimensions to three dimensions. This is the most creative characteristic of our technology," added Sungjae Hwang.

In the next month of August, the research team will present a paper on the MagPen technology, entitled "MagPen: Magnetically Driven Pen Interaction On and Around Conventional Smartphones" and receive an Honorable Mention Award at the 15th International Conference on Human-Computer Interaction with Mobile Devices and Services (MobileHCI 2013) to be held in Germany.

In addition to the MagPen, Hwang and his team are conducting other projects to develop different types of magnetic gadgets (collectively called "MagGetz") that include the Magnetic Marionette, a magnetic cover for a smartphone, which offers augmented interactions with the phone, as well as magnetic widgets such as buttons and toggle interface.

 

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Glass Scaffolds Help Heal Bone, Show Promise as Weight-Bearing Implants

Researchers at Missouri University of Science and Technology have developed a type of glass implant that could one day be used to repair injured bones in the arms, legs and other areas of the body that are most subject to the stresses of weight.


Missouri S&T researchers are using small, porous glass scaffolds like these to regenerate bone

This marks the first time researchers have shown a glass implant strong enough to bear weight can also integrate with bone and promote bone growth, says lead researcher Dr. Mohamed N. Rahaman, professor of materials science and engineering at Missouri S&T.

In previous work, the Missouri S&T researchers developed a glass implant strong enough to handle the weight and pressure of repetitive movement, such as walking or lifting. In their most recent study, published in the journal Acta Biomaterialia, the research team reported that the glass implant, in the form of a porous scaffolding, also integrates with bone and promotes bone growth.T         his combination of strength and bone growth opens new possibilities for bone repair, says Rahaman, who also directs Missouri S&T's Center for Biomedical Science and Engineering, where the research was conducted."Right now, there is no synthetic material that is practical for structural bone repair," Rahaman says.

Conventional approaches to structural bone repair involve either the use of a porous metal, which does not reliably heal bone, or a bone allograft from a cadaver. Both approaches are costly and carry risks, Rahaman says. He thinks the type of glass implant developed in his center could provide a more feasible approach for repairing injured bones. The glass is bioactive, which means that it reacts when implanted in living tissue and convert to a bone-like material.

In their latest research, Rahaman and his colleagues implanted bioactive glass scaffolds into sections of the calvarial bones (skullcaps) of laboratory rats, then examined how well the glass integrated with the surrounding bone and how quickly new bone grew into the scaffold. The scaffolds are manufactured in Rahaman's lab through a process known as robocasting -- a computer-controlled technique to manufacture materials from ceramic slurries, layer by layer -- to ensure uniform structure for the porous material.

In previous studies by the Missouri S&T researchers, porous scaffolds of the silicate glass, known as 13-93, were found to have the same strength properties as cortical bone. Cortical bones are those outer bones of the body that bear the most weight and undergo the most repetitive stress. They include the long bones of the arms and legs.

But what Rahaman and his colleagues didn't know was how well the silicate 13-93 bioactive glass scaffolds would integrate with bone or how quickly bone would grow into the scaffolding."You can have the strongest material in the world, but it also must encourage bone growth in a reasonable amount of time," says Rahaman. He considers three to six months to be a reasonable time frame for completely regenerating an injured bone into one strong enough to bear weight.

In their studies, the S&T researchers found that the bioactive glass scaffolds bonded quickly to bone and promoted a significant amount of new bone growth within six weeks.While the skullcap is not a load-bearing bone, it is primarily a cortical bone. The purpose of this research was to demonstrate how well this type of glass scaffolding -- already shown to be strong -- would interact with cortical bone. Rahaman and his fellow researchers in the Center for Biomedical Science and Engineering are now experimenting with true load-bearing bones. They are now testing the silicate 13-93 implants in the femurs (leg bones) of laboratory rats.

In the future, Rahaman plans to experiment with modified glass scaffolds to see how well they enhance certain attributes within bone. For instance, doping the glass with copper should promote the growth of blood vessels or capillaries within the new bone, while doping the glass with silver will give it antibacterial properties.

Curiosity Makes Its Longest One-Day Drive On Mars

NASA's Mars rover Curiosity drove twice as far on July 21 as on any other day of the mission so far: 109.7 yards (100.3 meters).

The Mars Hand Lens Imager (MAHLI) camera on NASA's Curiosity rover is carried at an angle when the rover's arm is stowed for driving. Still, the camera is able to record views of the terrain Curiosity is crossing in Gale Crater, and rotating the image 150 degrees provides this right-side-up scene. The scene is toward the south, including a portion of Mount Sharp and a band of dark dunes in front of the mountain. It was taken on the 140th Martian day, or sol, of Curiosity's work on Mars, shortly after Curiosity finished a 329.1-foot (100.3-meter) drive on that sol. The drive was twice as long as any previous sol's drive by Curiosity.

The length of the drive took advantage of starting the 340th Martian day, or sol, of the mission from a location with an unusually good view for rover engineers to plan a safe path. In weeks to come, the rover team plans to begin using "autonav" capability for the rover to autonomously navigate a path for itself, which could make such long drives more frequent.

Curiosity is about three weeks into a multi-month trek, from the "Glenelg" area where it worked for the first half of 2013, to an entry point for the mission's major destination: the lower layers of Mount Sharp. The mission's longest one-day drive prior to July 21 was about 54 yards (49 meters), on Sol 50 (Sept. 26, 2012). After completing the longer drive, Curiosity drove 68.2 yards (62.4 meters) on July 23 (Sol 342), bringing the mission's total driving distance so far to 0.81 mile (1.23 kilometers).

The Sol 340 drive included three segments, with turns at the end of the first and second segments. Rover planners used information from stereo imaging by the Navigation Camera (Navcam) on Curiosity's mast, plus images from the telephoto-lens Mast Camera (Mastcam). The drive also used the rover's capability to use imagery taken during the drive to calculate the driving distance, a way to verify that wheels have not been slipping too much while turning.

"What enabled us to drive so far on Sol 340 was starting at a high point and also having Mastcam images giving us the size of rocks so we could be sure they were not hazards," said rover planner Paolo Bellutta of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We could see for quite a distance, but there was an area straight ahead that was not clearly visible, so we had to find a path around that area."

The rover was facing southwest when the sol began. It turned slightly more to the west before driving and used visual odometry to be sure it drove the intended distance (about 55 yards or 50 meters) before turning back farther southward. The second leg, next turn, and third leg completed the drive without visual odometry, though the rover was using another new capability: to turn on visual odometry autonomously if tilt or other factors exceed predetermined limits.

New software on Curiosity gives it the capability to use visual odometry through a range of temperatures. This was needed because testing this spring indicated the Navcam pair linked to the rover's B-side computer is more sensitive to temperature than anticipated. Without the compensating software, the onboard analysis of stereo images could indicate different distances to the same point, depending on the temperature at which the images are taken. The rover was switched from its A-side computer to the redundant B-side computer on Feb. 28 due to a flash-memory problem -- subsequently resolved -- on the A-side. The Navcam pair linked to the A-side computer shows less variability with temperature than the pair now in use.

"For now, we're using visual odometry mostly for slip-checking," said JPL's Jennifer Trosper, deputy project manager for Curiosity. "We are validating the capability to begin using autonav at different temperatures."The autonomous navigation capability will enable rover planners to command drives that go beyond the route that they can confirm as safe from previous-sol images. They can tell the rover to use the autonomous capability to choose a safe path for itself beyond that distance.

Curiosity landed at the "Bradbury Landing" location within Gale Crater on Aug. 6, 2012, EDT and Universal Time (Aug. 5, PDT). From there, the rover drove eastward to the Glenelg area, where it accomplished the mission's major science objective of finding evidence for an ancient wet environment that had conditions favorable for microbial life. The rover's route is now southwestward. At Mount Sharp, in the middle of Gale Crater, scientists anticipate finding evidence about how the ancient Martian environment changed and evolved.

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. JPL designed and built the project's Curiosity rover.

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Computer Scientists Develop 'Mathematical Jigsaw Puzzles' to Encrypt Software

UCLA computer science professor Amit Sahai and a team of researchers have designed a system to encrypt software so that it only allows someone to use a program as intended while preventing any deciphering of the code behind it. This is known in computer science as "software obfuscation," and it is the first time it has been accomplished.

Concept illustration of mathematical jigsaw puzzle

 Sahai, who specializes in cryptography at UCLA's Henry Samueli School of Engineering and Applied Science, collaborated with Sanjam Garg, who recently earned his doctorate at UCLA and is now at IBM Research; Craig Gentry, Shai Halevi and Mariana Raykova of IBM Research; and Brent Waters, an assistant professor of computer science at the University of Texas at Austin. Garg worked with Sahai as a student when the research was done.

"The real challenge and the great mystery in the field was: Can you actually take a piece of software and encrypt it but still have it be runnable, executable and fully functional," Sahai said. "It's a question that a lot of companies have been interested in for a long time."

According to Sahai, previously developed techniques for obfuscation presented only a "speed bump," forcing an attacker to spend some effort, perhaps a few days, trying to reverse-engineer the software. The new system, he said, puts up an "iron wall," making it impossible for an adversary to reverse-engineer the software without solving mathematical problems that take hundreds of years to work out on today's computers -- a game-change in the field of cryptography.

The researchers said their mathematical obfuscation mechanism can be used to protect intellectual property by preventing the theft of new algorithms and by hiding the vulnerability a software patch is designed to repair when the patch is distributed.

The key to this successful obfuscation mechanism is a new type of "multilinear jigsaw puzzle." Through this mechanism, attempts to find out why and how the software works will be thwarted with only a nonsensical jumble of numbers."The real innovation that we have here is a way of transforming software into a kind of mathematical jigsaw puzzle," Sahai said. "What we're giving you is just math, just numbers, or a sequence of numbers. But it lives in this mathematical structure so that these individual pieces, these sequences of numbers, can only be combined with other numbers in very specified ways.

Functional encryption

The new technique for software obfuscation paved the way for another breakthrough called functional encryption. With functional encryption, instead of sending an encrypted message, an encrypted function is sent in its place. This offers a much more secure way to protect information, Sahai said. Previous work on functional encryption was limited to supporting very few functions; the new work can handle any computable function.

For example, a single message could be sent to a group of people in such a way that each receiver would obtain different information, depending on characteristics of that particular receiver. In another example, a hospital could share the outcomes of treatment with researchers without revealing details such as identifying patient information."Through functional encryption, you only get the specific answer, you don't learn anything else," Sahai said.

The UCLA-based researchers were funded in part by the National Science Foundation, a Xerox Faculty Research Award, a Google Faculty Research Award, an equipment grant from Intel and an Okawa Foundation Research Grant.