Group items tagged

These features lead to a high heat-to-electricity energy conversion efficiency of 5.7% when cycled between 10 and 60 °C, opening a promising way to utilize low-grade heat.

A personal interest of mine that I want to explore a bit more in the future. I just bought a ZigBee electricity monitor and I am wondering whether from the signal of the mains one could detect (reliably) the oven turning on, lights, etc. Probably requires Neural Network training. The idea would be to make a simple device which basically saves you money by telling you how much electricity you are wasting. Then again, its probably already done by Google...

Randomly I found this: http://spectrum.ieee.org/view-from-the-valley/consumer-electronics/gadgets/curb-startup-home-electricity-tracking Isn't it a similar kind of stuff Thijs?

haha, yep, that's it... but we can do better than that right! :)

not sure what to make of this. seems like an odd change of direction "Spaceports will be key to us opening up the final frontier of commercial space travel," said Chief Secretary to the Treasury Danny Alexander at the announcement of the new sites. Mr Alexander hinted that the plans could lead to Scotland becoming the home of the UK's commercial space ambitions, even as the Scottish government warns that only independence will secure a successful space industry for the country.

An exhaustive overview of all possible advanced rocket concepts, eg.. "As an example, consider a photon rocket with its launching mass, say, 1000 ton moving with a constant acceleration a =0.1 g=0.98 m/s2. The flux of photons with E γ=0.5 MeV needed to produce this acceleration is ~1027/s, which corresponds to the efflux power of 1014 W and the rate of annihilation events N'a~5×1026 s−1 [47]. This annihilation rate in ambiplasma l -l ann corresponds to the value of current ~108 A and linear density N ~2×1018 m−1 thus any hope for non-relativistic relative velocity of electrons and positrons in ambiplasma is groundless." And also, even if it would work, then one of the major issues is going to be heat dispersal: "For example, if the temperature of radiator is chosen T=1500 K, the emitting area should be not less than 1000 m2 for Pb=1 GW, not less than 1 km2 for Pb=1 TW, and ~100 km2 for Pb=100 TW, assuming ε=0.5 and δ=0.2. Lower temperature would require even larger radiator area to maintain the outer temperature of the engine section stable for a given thermal power of the reactor."

The problem is not achieving a high energy density, that we can already do with nuclear fission, the question however is how to confine or harness this power with relatively high efficiency, low waste heat and at not too crazy specific mass. I see magnetic confinement as a possibility, yet still decades away and also an all-or-nothing method as we cannot easily scale this up from a test experiment to a full-scale system. It might be possible to extract power from such a plasma, but definitely well below breakeven so an additional power supply is needed. The fission fragments circumvent these issues by a more brute force approach, thereby wasting a lot of energy for sure but at the end probably providing more ISP and thrust.

Sure. However, the annihilation based photon rocket concept unifies almost all relevant drawbacks if we speak about solar system scales, making itself obsolete...it is just an academic testcase.

Browsing Kaggle...

Very nice library, we actually use it for GTOC7.

You've heard of the catastrophic effects of radiation on environments, animals and humans. A seemingly silent and invisible destroyer, radiation can make whole cities inhabitable for hundreds of years. But have you ever wondered what radiation actually looks like? There may be one image that jumps to mind. We saw the same detector setup in the room opposite to ours during the Open Day! Using uranium is just cooler. :)

A total storage of 9.5 wt% H2 could be reached which is above the 7.5wt% set by the DoE for market requirements of hydrogen vehicles. The nanoboxes can be opened and closed using electric fields.

Not new, but always good to read: British intelligence recommend not having password expiry dates. Something we should apply at ESA!

I second that. It has been an open secret for long though that frequent password changes are creating more problems than they solve. See Bruce Schneier: https://www.schneier.com/blog/archives/2016/08/frequent_passwo.html

Just read some of the samples of text generated with their neural networks, insane.

It's really lucky that it was OpenAI who made that development and Elon Musk is so worried about AI. This way at least they try to assess the whole spectrum of abilities and applications of this model before releasing the full research to the public.

They released a smaller model, I got it running on Sandy. It's fairly straight forward: https://github.com/openai/gpt-2

This has attracted a lot of attention in the DL community lately. Article: https://lilianweng.github.io/lil-log/2017/09/28/anatomize-deep-learning-with-information-theory.html Paper: https://arxiv.org/pdf/1703.00810.pdf

microsoft just bought github ...

Took 2000 GPUs over 2 weeks to train :)

I agree soooo very much. An increasing number of journal and scientists are finally coming on board with this open science philosophy and I bet we will soon see a radical change of the whole peer review process and publication business

Might be of interest for torchquad and other projects