Four short links: 15 February 2019
Four Wings, Efficient Streaming Calculations, Closed AI, Quantum Research
- For Micro Robot Insects, Four Wings May Be Better Than Two (IEEE Spectrum) — This robot uses the same sort of piezoelectric actuators as Harvard’s RoboBee, just rotated sideways. At 143 milligrams, it weighs just about as much as a real honeybee, but the key statistic is that it’s capable of lifting an additional 260 mg (at least), which ought to be enough for both sensors and a battery or supercapacitor. The extra power comes from the extra wings, of course, and while you can’t simply double payload capacity by doubling the number of wings, you can, hopefully, go from “not quite enough payload” to “just barely enough payload.”
- Computing Extremely Accurate Quantiles Using t-Digests — We present on-line algorithms for computing approximations of rank-based statistics that give high accuracy, particularly near the tails of a distribution, with very small sketches. Notably, the method allows a quantile q to be computed with an accuracy relative to max(q,1−q) rather than absolute accuracy as with most other methods. This new algorithm is robust with respect to skewed distributions or ordered data sets and allows separately computed summaries to be combined with no loss in accuracy. (via Ellen Friedman)
- GPT-2: Better Language Models (OpenAI) — their first output not released as open source because its text-generation skills are excellent. It could readily be used to make a bot army on Twitter. This indicates a change in where the line between “research best done in the open” and “giving away weapons” is drawn. These findings, combined with earlier results on synthetic imagery, audio, and video, imply that technologies are reducing the cost of generating fake content and waging disinformation campaigns. The public at large will need to become more skeptical of text they find online, just as the “deep fakes” phenomenon calls for more skepticism about images. See also The Verge’s writeup.
- Quantum Computing, Capabilities and Limits: An Interview with Scott Aaronson (GigaOm) — interesting and readable for the non-quantum mechanic. I think it’s too early to identify any Moore’s Law pattern. I mean, for god sakes, we don’t even know which technology is going to be the right one. The community is not converged around whether it’s going to be superconducting or trapped ions or something else. You can make plots of the number of qubits and the coherence time of those qubits, and you do see a strong improvement. But the number of qubits—let’s say it’s gone up from one or two to 20; it’s kind of hard to see an exponential in those numbers.