Implication of Sabotage Adds Intrigue To SpaceX Investigation

Slashdot - Sat, 01/10/2016 - 10:00am
An anonymous reader quotes a report from The Washington Post: The long-running feud between Elon Musk's space company and its fierce competitor United Launch Alliance took a bizarre twist this month when a SpaceX employee visited its facilities at Cape Canaveral, Fla., and asked for access to the roof of one of ULA's buildings. About two weeks earlier, one of SpaceX's rockets blew up on a launchpad while it was awaiting an engine test. As part of the investigation, SpaceX officials had come across something suspicious they wanted to check out, according to three industry officials with knowledge of the episode. SpaceX had still images from video that appeared to show an odd shadow, then a white spot on the roof of a nearby building belonging to ULA, a joint venture between Lockheed Martin and Boeing. The SpaceX representative explained to the ULA officials on site that it was trying to run down all possible leads in what was a cordial, not accusatory, encounter, according to the industry sources, who spoke on the condition of anonymity because of the ongoing investigation. The building, which had been used to refurbish rocket motors known as the SMARF, is just more than a mile away from the launchpad and has a clear line of sight to it. A representative from ULA ultimately denied the SpaceX employee access to the roof and instead called Air Force investigators, who inspected the roof and didn't find anything connecting it to the rocket explosion, the officials said. This week, ten members of Congress sent a four-page letter to several government agencies about the SpaceX explosion, raising the question as to whether or not SpaceX should be leading the investigation. Elon Musk said the investigation into what went wrong is the company's "absolute top priority." He added, "We've eliminated all of the obvious possibilities for what occurred there. So what remains are the less probable answers." SpaceX aims to resume flights in November.

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Categories: Science

Rosetta's 12-Year Mission Ends With Landing On Comet

Slashdot - Sat, 01/10/2016 - 7:00am
sciencehabit writes: It was an unusual grand finale. The crowded European Space Agency (ESA) operations center in Darmstadt, Germany, waited in silence and then the signal from the descending Rosetta mission simply stopped at 1.19 pm local time showing that the spacecraft had, presumably, landed on comet 67P/Churyumov-Gerasimenko some 40 minutes earlier, due to the time the signal takes to reach Earth. Mission controllers hugged each other; there was gentle applause from onlookers; and that was it. There were no last minute crises. Seven of Rosetta's instruments kept gathering data until the end. Holger Sierks, principal investigator of the 12-year mission's main camera, showed the gathered staff, officials, and journalists Rosetta's final picture: a rough gravelly surface with a few larger rocks covering an area 10 meters across. Earlier, it had snapped the interior of deep pits on the comet (shown above, from an altitude of 5.8 kilometers) that may show the building blocks it is made of. "It's very crude raw data but this will keep us busy," Sierks said. It is hoped that this last close-up data grab will help to clarify the many scientific questions raised by Rosetta.

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Categories: Science

Synapse-like memristor-based electronic device detects brain spikes in real time

Kurzweil AI - Sat, 01/10/2016 - 3:34am

Memristor chip (credit: University of Southampton)

A bio-inspired electronic device called a memristor could allow for real-time processing of neuronal signals (spiking events), new research led by the University of Southampton has demonstrated.

The research could lead to using multi-electrode array implants for detecting spikes in the brain’s electrical signals from more than 1,000 recording channels to help treat neurological conditions, without requiring expensive, high-bandwidth, bulky systems for processing data. The research could lead to future autonomous, fully implantable neuroprosthetic devices.

Schematic illustration of a solid-state titanium-oxide memristive device and atomic force microscopic (AFM) image a portion of a 32 × 32 crossbar array of memristors (credit: Isha Gupta/Nature Communications)

A memristors is an electronic component that limits or regulates the flow of electrical current in a circuit, can remember the amount of charge that was flowing through it, and retain that data, even when the power is turned off. The researchers used an array of memristors.

The research team designed a new nanoscale device they called a “memristive integrating sensor” (MIS) based on a memristors and associated electronic circuits for detecting spikes.*

Acting like synapses in the brain, the MIS was able to encode and compress (up to 200 times) neuronal spiking activity recorded by multi-electrode arrays. Besides addressing the bandwidth constraints, this approach was also very power-efficient; the power needed per recording channel was up to 100 times less when compared to current best practice.

The research was published in the open-access journal Nature Communications.

The Prodromakis Group at the University of Southampton collaborated among others with Leon Chua (a Diamond Jubilee Visiting Academic at the University of Southampton), who theoretically predicted the existence of memristors in 1971.

This interdisciplinary work was supported by an FP7 project (the European Union’s Research and Innovation funding) and brought together engineers from the Nanoelectronics and Nanotechnology Group at the University of Southampton with biologists from the University of Padova and the Max Planck Institute, Germany, using the state-of-art facilities of the Southampton Nanofabrication Centre.

* The paper explains that signals from an array of neural electrodes are fed into the MIS system as a series of voltage-time samples. “The MIS begins by pre-amplifying the incoming signal to voltage levels suitable for operating the memristor sitting at the core of the MIS and then proceeding to apply the pre-amplified signals to the memristor in real-time. The memristor’s resistive state is assessed periodically and when a significant change in comparison to the previous state is detected, the system registers a spiking event.”

Abstract of Real-time encoding and compression of neuronal spikes by metal-oxide memristors

Advanced brain-chip interfaces with numerous recording sites bear great potential for investigation of neuroprosthetic applications. The bottleneck towards achieving an efficient bio-electronic link is the real-time processing of neuronal signals, which imposes excessive requirements on bandwidth, energy and computation capacity. Here we present a unique concept where the intrinsic properties of memristive devices are exploited to compress information on neural spikes in real-time. We demonstrate that the inherent voltage thresholds of metal-oxide memristors can be used for discriminating recorded spiking events from background activity and without resorting to computationally heavy off-line processing. We prove that information on spike amplitude and frequency can be transduced and stored in single devices as non-volatile resistive state transitions. Finally, we show that a memristive device array allows for efficient data compression of signals recorded by a multi-electrode array, demonstrating the technology’s potential for building scalable, yet energy-efficient on-node processors for brain-chip interfaces.

Categories: Science

How to send secure passwords through your body instead of air

Kurzweil AI - Fri, 30/09/2016 - 5:42am

Potential applications for on-body transmissions include securely sending information to door locks, glucose sensors, or other wearable medical devices. (credit: Vikram Iyer, University of Washington)

University of Washington computer scientists and electrical engineers have devised a way to send secure passwords through the human body, using benign, low-frequency transmissions already generated by fingerprint sensors and touchpads on consumer devices.

“Let’s say I want to open a door using an electronic smart lock,” said Merhdad Hessar, a UW electrical engineering doctoral student and co-lead author of a paper presented in September at the 2016 Association for Computing Machinery’s International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp 2016) in Germany. “I can touch the doorknob and touch the fingerprint sensor on my phone and transmit my secret credentials through my body to open the door, without leaking that personal information over the air.”

Secure on-body transmissions

These “on-body” transmissions offer a more secure way to transmit authenticating information between devices that touch parts of your body — such as a wearable medical device — and a phone or device that confirms your identity by asking you to type in a password.

The technology could also be useful for secure key transmissions to medical devices which seek to confirm someone’s identity before sending or sharing data, such as glucose monitors or insulin pumps.

The research team tested the technique on iPhone and other fingerprint sensors, as well as Lenovo laptop trackpads and the Adafruit capacitive touchpad. In tests with ten different subjects, they were able to generate usable on-body transmissions on people of different heights, weights and body types. The system also worked when subjects were in motion, including while they walked and moved their arms.

The researchers showed that it works in different postures like standing, sitting and sleeping, and they can get a strong signal throughout your body, with receivers on any part of the body.

Reverse-engineering and repurposing smartphone sensors

The research team from the UW’s Networks and Mobile Systems Lab systematically analyzed smartphone sensors to understand which of them generates low-frequency transmissions below 30 megahertz (which travel well through the human body but don’t propagate over the air).

The researchers found that fingerprint sensors and touchpads generate signals in the 2 to 10 megahertz range and employ capacitive coupling to sense where your finger is in space and to identify the ridges and valleys that form unique fingerprint patterns.

Normally, sensors use these signals to receive input about your finger. But the UW engineers devised a way to use these signals as output that corresponds to data contained in a password or access code. When entered on a smartphone, data that authenticates your identity can travel securely through your body to a receiver embedded in a device that needs to confirm who you are.

Their process employs a sequence of finger scans to encode and transmit data. Performing a finger scan correlates to a 1-bit of digital data and not performing the scan correlates to a 0-bit. The team achieved bit rates of 50 bits per second on laptop touchpads and 25 bits per second with fingerprint sensors — fast enough to send a simple password or numerical code through the body and to a receiver within seconds.

This represents only a first step, the researchers say. Data can be transmitted through the body even faster if fingerprint sensor manufacturers provide more access to their software.

The research was funded by the Intel Science and Technology Center for Pervasive Computing, a Google faculty award and the National Science Foundation.

For more information, contact the research team at onbody@cs.washington.edu.

Abstract of Enabling on-body transmissions with commodity devices

We show for the first time that commodity devices can be used to generate wireless data transmissions that are confined to the human body. Specifically, we show that commodity input devices such as fingerprint sensors and touchpads can be used to transmit information to only wireless receivers that are in contact with the body. We characterize the propagation of the resulting transmissions across the whole body and run experiments with ten subjects to demonstrate that our approach generalizes across different body types and postures. We also evaluate our communication system in the presence of interference from other wearable devices such as smartwatches and nearby metallic surfaces. Finally, by modulating the operations of these input devices, we demonstrate bit rates of up to 50 bits per second over the human body.

Categories: Science

Graphene crowd-surfs on a lipid monolayer

Kurzweil AI - Fri, 30/09/2016 - 4:26am

Model of graphene on a lipid monolayer (credit: Universiteit Leiden)

“Crowd-surfing” on a smooth, supportive lipid monolayer, graphene could provide a versatile new platform for biosensors and drug delivery systems, researchers at Leiden University in The Netherlands have discovered.

Graphene is typically supported or sandwiched with other two-dimensional materials to promote higher mobility, ensure consistent electrical performance, and prevent environmental contamination. But combining graphene with soft, dynamic, molecular self-assembled lipid monolayers could provide a versatile platform for applications such as biosensors and drug delivery systems.

In research results published (open access) in a cover story in the journal Nanoscale on September 28, the authors note that the lipids (surprisingly) also improve graphene’s electrical conductivity. That could allow for measuring the electrical signals of graphene in the body for detecting acidity or the presence of certain proteins, for example. This research was funded by the European Research Council, the Netherlands Organization for Scientific Research, and the Swiss National Science Foundation. Abstract of Graphene-stabilized lipid monolayer heterostructures: a novel biomembrane superstructure

Chemically defined and electronically benign interfaces are attractive substrates for graphene and other two-dimensional materials. Here, we introduce lipid monolayers as an alternative, structurally ordered, and chemically versatile support for graphene. Deposition of graphene on the lipids resulted in a more ordered monolayer than regions without graphene. The lipids also offered graphene a more uniform and smoother support, reducing graphene hysteresis loop and the average value of the charge neutrality point under applied voltages. Our approach promises to be effective towards measuring experimentally biochemical phenomena within lipid monolayers and bilayers.

Categories: Science