In the prototype plane, wires at the leading edge of the wing have 600 watts of electrical power pumped through them at 40,000 volts. This is enough to induce “electron cascades”, ultimately charging air molecules near the wire. Those charged molecules then flow along the electrical field towards a second wire at the back of the wing, bumping into neutral air molecules on the way, and imparting energy to them. Those neutral air molecules then stream out of the back of the plane, providing thrust.
n the end, this isn’t a debate about facts, say Masnick’s lawyers. Both Ayyadurai and Masnick acknowledge that the MAILBOX program was created at MIT in the 1960s and that Ray Tomlinson created the “@” symbol protocol in 1971. The two draw different conclusions, however. Ayyadurai calls the ARPANET creations “command-line protocols for transferring text messages” or “primitive electronic communication systems.” In Masnick’s view, Ayyadurai doesn’t dispute the historical facts, but instead “attacks Techdirt’
The reliance on static underground features is LGPR’s advantage as a complement to other localization methods, even in fair weather conditions. The use of a subsurface map reduces the need for continual modifications to high-resolution road maps. Fusing GPS, lidar, camera, and LGPR results yields a system that can accurately localize even when one of the sensing modes fails. This “fail-safe” capability will be necessary to the development of dependable autonomous vehicles that can handle demanding ground environments.
CSAIL says Barry’s software runs 20 times faster than existing obstacle detection software. Operating at 120 frames per second, the open-source software allows the drone to detect objects and map its environment in real time, extracting depth information at 8.3 milliseconds per frame.
Barry wrote about the system in his paper “Pushbroom Stereo for High-Speed Navigation in Cluttered Environments” (PDF) and says he needs to improve the software so it can work at more than one depth and dense environments.
Because a SLAM map is three-dimensional, however, it does a better job of distinguishing objects that are near each other than single-perspective analysis can. The system devised by Pillai and Leonard, a professor of mechanical and ocean engineering, uses the SLAM map to guide the segmentation of images captured by its camera before feeding them to the object-recognition algorithm. It thus wastes less time on spurious hypotheses.
More important, the SLAM data let the system correlate the segmentation of images captured from different perspectives. Analyzing image segments that likely depict the same objects from different angles improves the system’s performance.
Source: Object recognition for robots
We have found that the damage that could be caused by law enforcement exceptional access requirements would be even greater today than it would have been 20 years ago. In the wake of the growing economic and social cost of the fundamental insecurity of today’s Internet environment, any proposals that alter the security dynamics online should be approached with caution. Exceptional access would force Internet system developers to reverse forward secrecy design practices that seek to minimize the impact on user privacy when systems are breached. The complexity of today’s Internet environment, with millions of apps and globally connected services, means that new law enforcement requirements are likely to introduce unanticipated, hard to detect security flaws.
As an example, the researchers wrote about looking at data from September 23 and 24 and who went to a bakery one day and a restaurant the other. Searching through the data set, they found there could be only person who fits the bill – they called him Scott. The study said, “and we now know all of his other transactions, such as the fact that he went shopping for shoes and groceries on 23 September, and how much he spent.”
Normally, Fang explains, stiffness and strength declines with the density of any material; that’s why when bone density decreases, fractures become more likely. But using the right mathematically determined structures to distribute and direct the loads — the way the arrangement of vertical, horizontal, and diagonal beams do in a structure like the Eiffel Tower — the lighter structure can maintain its strength.
The ceramic material Powell showed me—which is made of zirconium oxide—replaces the carbon electrode and eliminates those emissions. Researchers have been trying to replace carbon for many years, but the molten salts have corroded the alternatives. The key advance for Infinium was developing alternative molten salts that don’t react with the zirconium oxide, so that it can last long enough to be practical.
Finding an alternative to carbon has long been the “dream” of the metals industry, says Donald Sadoway, a professor of materials science at MIT who is not involved with the company. “I believe [Infinium’s] technology is sound. It’s real,” he says. Whether the company succeeds “is all about the economics,” he says. “No one cares about the flow chart for the process. You care about the prices. If it produces a good metal at a lower cost, people will be interested.”
An RLNC transmission can recover from errors with neither sender nor receiver retaining and updating transmission-state information and requesting lost packets to be retransmitted. This is because RLNC can recreate any packet lost on the receiving side from a later sequenced packet. In over-simplified terms, each RLNC encoded packet sent is encoded using the immediately earlier sequenced packet and randomly generated coefficients, using a linear algebra function. The combined packet length is no longer than either of the two packets from which it is composed. When a packet is lost, the missing packet can be mathematically derived from a later-sequenced packet that includes earlier-sequenced packets and the coefficients used to encode the packet.
Since the RLNC encoding sender doesn’t need to listen for acknowledgements of successful transmission and perhaps retransmit, the sender can continuously transmit at near-wire speed optimized for latency and network throughput.
Update: After posting this I remembered I had read about an algorithm recreating earlier lost packets from future packets. So I clicked on the mit tag and on 10/25/2012 I posted this blurb: A Bandwidth Breakthrough
… The technology transforms the way packets of data are sent. Instead of sending packets, it sends algebraic equations that describe series of packets. So if a packet goes missing, instead of asking the network to resend it, the receiving device can solve for the missing one itself. …
That must mean they’re still working on it.