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U.S. court: Mass surveillance program exposed by Snowden was illegal

2020-09-02 Raphael Satter

(Reuters) – Seven years after former National Security Agency contractor Edward Snowden blew the whistle on the mass surveillance of Americans’ telephone records, an appeals court has found the program was unlawful – and that the U.S. intelligence leaders who publicly defended it were not telling the truth.


Memristor Breakthrough: First Single Device To Act Like a Neuron

2020-09-01 Samuel K. Moore

It combines resistance, capacitance, and what’s called a Mott memristor all in the same device. Memristors are devices that hold a memory, in the form of resistance, of the current that has flowed through them. Mott memristors have an added ability in that they can also reflect a temperature-driven change in resistance. Materials in a Mott transition go between insulating and conducting according to their temperature. It’s a property seen since the 1960s, but only recently explored in nanoscale devices.

The transition happens in a nanoscale sliver of niobium oxide in the memristor. Here when a DC voltage is applied, the NbO2 heats up slightly, causing it to transition from insulating to conducting. Once that switch happens, the charge built up in the capacitance pours through. Then the device cools just enough to trigger the transition back to insulating. The result is a spike of current that resembles a neuron’s action potential.


Artificial brains may need sleep too

2020-06-08 James Riordon

States that resemble sleep-like cycles in simulated neural networks quell the instability that comes with uninterrupted self-learning in artificial analogs of brains

Watkins and her research team found that the network simulations became unstable after continuous periods of unsupervised learning. When they exposed the networks to states that are analogous to the waves that living brains experience during sleep, stability was restored. “It was as though we were giving the neural networks the equivalent of a good night’s rest,” said Watkins.