Month: June 2015

Fujitsu Laboratories has developed a software-based technology to increase data-transfer speeds for accessing files on remote enterprise file-sharing servers. When accessing remote file-sharing servers in the cloud, slow upload and download speeds for typical file-sharing systems due to network latency has been an issue. By using a newly developed software that relays communications between the client and server, the number of communications made has been significantly reduced, lowering the effects of network latency. This communication frequency occurs when obtaining information on multiple file names and file sizes on a remote network. In an internal experiment, file transfers were confirmed to be up to ten times faster when dealing with multiple small files. Transfers of large files can be up to twenty times faster when combined with the deduplication technology Fujitsu Laboratories announced last year. By simply installing this software on a client and server, increased speeds for file access for existing file-sharing systems can be achieved.

In file sharing, files are stored on server connected to a network and multiple clients can share the same files. This is used by enterprises to share information and manage documents. Previously, Individual locations have maintained their own file-sharing servers on-site, but in order to improve security and reduce operating costs through combined management, server consolidation has become more common as have opportunities to remotely access file-sharing servers. With two network file-sharing protocols that are widely used in file-sharing systems, CIFS and SMB, the effects of network latency can impose significant wait times for accessing files, creating a demand for improving speed.

Technologies Issues

Fujitsu Laboratories has already developed a deduplication technology for use with remote data transfers, which accelerates the process by avoiding retransmissions of previously sent data. This technology can be applied to a variety of situations, but it has had limited effectiveness with the CIFS and SMB file-sharing protocols because of their unique processes. Improving networks and installing specialized hardware are other ways of increasing speeds, but these are expensive, and installation of specialized hardware has limited effectiveness when handling large numbers of small files only a few kilobytes in size. The CIFS and SMB file-sharing protocols have the following unique processes and challenges.
When copying a folder containing a large number of files, all of the file-attribute information is requested for each file, and the accumulation of these requests in a remote network causes significant latency (Figure 1).
When sending relatively large files, their data is split into pieces tens of kilobytes in size, and header information is attached to each data. Because this header information is updated each time, the transmitted data becomes different even if it sends the same file, which makes deduplication ineffective.

Fujitsu Laboratories has developed a technology that accelerates data transfers for file-sharing servers using only software. Key features of the technology are as follows.

1. Collectively proxy read-ahead for multiple files and proxy response

With this technology, a module is installed on both the client and server that accelerates data transfers (Figure 2). The server-side module: 1) identifies when a folder containing multiple files starts to download; 2) read-ahead on the client proxy the batch of all the files downloaded; 3) these read-ahead files are bundled together and transmitted to the client-side module; and 4) the client-side module then replies to a request to get data with its server proxy. In this way, the amount of communications generated by obtaining file attributes, such as multiple file names and file sizes, is greatly reduced, as are the delays influenced by network latency.

2. Effective deduplication due to header separation

Fujitsu Laboratories developed a technology that works on the server-side module to separate the transmitted data into the headers and the contents of file. This makes deduplication of retransmitted data more precise, leading to more effective network traffic reduction.
In Fujitsu Laboratories’ internal experiment, software that implements this technology was found to have the following effects.
Increase in speed of multiple small file transfers: In a test environment that simulated the network latency for accessing a file-sharing server in Kawasaki from a location in Kyushu, batch downloads of folders containing one hundred 1-KB files was found to be ten times faster.
Increase in speed of large file transfers: In the same test environment, a download of a single 10 MB file was found to be as much as twenty times faster (compared with having no acceleration technologies such as deduplication).
This technology is implemented as software and can be installed on existing file-sharing systems. It can also be applied to cloud and server-virtualization environments, mobile devices, etc., and can be extended to a variety of network services. This technology enables more efficient file sharing and joint development between remote locations.
Fujitsu Laboratories plans to implement this technology into a product as a function for a WAN optimization solution during fiscal 2015, after internal testing at Fujitsu.

References:http://phys.org/

 

Robots inspired by cockroaches can use the shape of their bodies — particularly, their distinctive round shells — to maneuver through dense clutter, which could make them useful in search-and-rescue missions, military reconnaissance and even on farms, according to a new study.

Although many research teams have designed robots that can avoid obstacles, these bots mostly do so by evading stumbling blocks. This avoidance strategy typically uses sensors to map out the environment and powerful computers to plan a safe path around the obstacles.

“This approach has been very successful — for example, Google’s self-driving car,” said lead study author Chen Li, a physicist at the University of California, Berkeley.

“However, it does have limitations,” Li told Live Science. “First, when the terrain becomes densely cluttered — where gaps become comparable to, or even smaller than, robot size — a clear path where robots do not hit obstacles cannot be planned, because obstacles are just too close to each other. Second, this approach requires sophisticated sensors and computers, which are often too large or heavy for small robots to carry around.”

Instead, Li and his colleagues wanted to design robots that did not avoid obstacles, but traversed them. They sought their inspiration from discoid cockroaches, which are about 2 inches (4.9 centimeters) long. These roaches usually live on the floor of tropical rainforests, where they frequently encounter a wide variety of clutter, such as grass, shrubs, leaves, tree trunks and mushrooms.

The scientists used high-speed cameras to analyze how the cockroaches moved through artificial obstacle courses with closely spaced, grasslike beams made of card stock. Over the course of hundreds of runs, the insects usually completed the obstacle courses in about 3 seconds. Although the roaches sometimes pushed through the beams or climbed over them, nearly half the time, the insects quickly and effectively slipped past the beams by rolling their bodies to fit through the gaps and using their legs to push off the beams. [See video of the robot cockroach evading obstacles]

Then, the researchers fitted the cockroaches with three artificial shells of different shapes — an oval cone similar to the roaches’ bodies, a flat oval and a flat rectangle — to see what factors influence the insects’ movements. When the glued-on shells made the roaches less round, the insects were less able to perform a roll and maneuver past the obstacles, the researchers found.

Then, the scientists tested a 4-inch-long (10 cm) six-legged robot named VelociRoACH on a similar obstacle course. When it had a rectangular body, the robot had only a 19 percent chance of passing the course, since it frequently got stuck between the grasslike beams. However, when it was fitted with a cockroach-inspired round shell, it had a 93 percent chance of finishing the obstacle course by rolling through the beams, in much the same way real roaches did. This move did not involve any change to the robot’s programming or the addition of any sensors — it was a natural consequence of the shell, the researchers said.

“Robots can take advantage of effective physical interactions with the environment to traverse even densely cluttered obstacles,” Li said.

This research shows how body shapes can help animals and robots traverse terrain, much like how the streamlined body shapes of many birds and fishes (and mimicked by airplanes and submarines) help reduce drag, Li added. “This is why we named this new concept ‘terradynamic streamlining,'” he said.

Terradynamic streamlining may prove especially useful for small, inexpensive robots in applications like search and rescue, precision farming, or military reconnaissance because it allows the bots to traverse obstacles like rubble and vegetation without having to add more sensors and computers, Li said.

“There may well be other body shapes that are good for other purposes, such as climbing up and over obstacles,” Li said. In the future, the researchers plan to analyze how animal and robot body shapes affect other kinds of movement in a variety of environments.

The scientists detailed their findings online June 23 in the journal Bioinspiration & Biomimetics.

References:http://www.livescience.com/

A molecule has become the world’s smallest movie star.

For the first time, scientists have observed a chemical reaction as it was happening at the molecular level, at speeds that previously were too fast to see. The experiment could lead to insights about how complex molecules behave and why they take the shapes they do.

At the SLAC National Accelerator Laboratory, a team of researchers used two laser beams — one in the ultraviolet and another in the X-ray wavelengths — to get a picture of a chemical called 1,3-cyclohexadiene (CHD) as it morphed into another form called 1,3,5-hexatriene. They captured images of the reaction on a scale of femtoseconds, or millionths of a billionth of a second.

“We kind of know what CHD looks like,” Michael Minitti, lead author of the new study and a staff scientist at SLAC told Live Science. “The issue was the steps between one form and another.”

CHD is made of six carbon atoms in a ring with hydrogen atoms on the outside, like spokes. When ultraviolet light of a certain wavelength hits it, one of the carbon bonds breaks, and the CHD turns into 1,3,5-hexatriene. The latter chemical is made of the same chemical elements but is arranged to form a different shape.
Such reactions are called electrocyclic, and they show up in a lot of different places — for example, it’s one of the ways animals synthesize vitamin D from sunlight. Although they’re common, electrocyclic reactions aren’t so well understood. A big question for physical chemists has been what happens to a molecule like CHD after it gets hit by the UV light but before it turns into 1,3,5-hexatriene.

To make their movie, the researchers first put a gaseous form of the CHD into a chamber at very low pressure. Then, they fired the ultraviolet laser at it, breaking one of the carbon bonds. The next step was to use an X-ray laser to zap the molecule. The X-ray laser flashes lasted only a few femtoseconds, as the whole reaction from CHD to hexatriene takes less than 200 femtoseconds to complete.

The X-rays scattered off of the molecules, and by looking at a pattern of light and dark on a detector, the researchers could read the shape of the molecule. Firing the X-ray laser repeatedly over a tiny fraction of a second showed how the shape changed over time.

The technique is similar to X-ray diffraction used when investigating the structure of DNA or crystals. (In fact, the structure of DNA was discovered in just this way in the 1950s.) There are crucial differences, though: X-ray diffraction doesn’t measure anything over time, so the resulting picture is static; the X-rays in this new experiment were generated by a laser; and CHD is a gas, unlike the DNA molecule. “Gas molecules don’t have a structure,” Minitti said. “It looks like someone sneezed on the detector.”

When chemists can see the way the shape changes, it tells them how such chemicals transform in a specific way that wasn’t known before. Molecules tend to go to states of minimum energy, just as a ball rolling between two hills will tend to fall to the bottom and stay there. Regions of high and low potential energy surround the molecule, and when that molecule changes shape, its atoms will tend to stay in the low-energy regions. That means the shapes are specific, and knowing what they are offers insight into the processes that create the final forms.

While the research team was able to see the CHD change, the resolution in time —corresponding to the number of “frames” in an ordinary film — wasn’t quite high enough to see every step, Minitti said. Each “frame” was about 25 femtoseconds, so there would be about eight in the animation. In the next experiment, scheduled for January 2016, he hopes to get a better picture of the changes with smaller intervals. Even so, the new experiment shows that such molecular moviemaking is possible.

References:http://www.livescience.com/