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Big data analytic systems are reputed to be capable of finding a needle in a universe of haystacks without having to know what a needle looks like. The very best ways to sort large databases of unstructured text is to use a technique called Latent Dirichlet allocation (LDA). Unfortunately, LDA is also inaccurate enough at some tasks that the results of any topic model created with it are essentially meaningless, according to Luis Amaral, a physicist whose specialty is the mathematical analysis of complex systems and networks in the real world and one of the senior researchers on the multidisciplinary team from Northwestern University that wrote the paper. Even for an easy case, big data analysis is proving to be far more complicated than many of the companies selling analysis software want people to believe.

Most of those companies are using outdated algorithms like this LDA and just apply them like retards on those huge datasets. Of course they're going to come out with bad solutions. No amount of data can make up for bad algorithms.

The first complete theory of how plasmons produce "hot carriers" has been developed by researchers in the US. The new model could help make this process of producing carriers more efficient, which would be good news for enhancing solar-energy conversion in photovoltaic devices.

I did not read the paper but what is further down written in the article, does not give much hope that this actually gives much more insight than what we had nor that it could be used in any way to improve current PV cells soon: e.g. "To fully exploit these carriers for such applications, researchers need to understand the physical processes behind plasmon-induced hot-carrier generation. Nordlander's team has now developed a simple model that describes how plasmons produce hot carriers in spherical silver nanoparticles and nanoshells. The model describes the conduction electrons in the metal as free particles and then analyses how plasmons excite hot carriers using Fermi's golden rule - a way to calculate how a quantum system transitions from one state into another following a perturbation. The model allows the researchers to calculate how many hot carriers are produced as a function of the light frequency used to excite the metal, as well as the rate at which they are produced. The spectral profile obtained is, to all intents and purposes, the "plasmonic spectrum" of the material. Particle size and hot-carrier lifetimes "Our analyses reveal that particle size and hot-carrier lifetimes are central for determining both the production rate and the energies of the hot carriers," says Nordlander. "Larger particles and shorter lifetimes produce more carriers with lower energies and smaller particles produce fewer carriers, but with higher energies."

Today we released the Astro Drone app. People that have the Parrot AR drone can freely download the game. While they fly their drone in the real world, they are trying to dock to the ISS in the virtual world. But the app is more than a game. Players can choose to participate in a scientific crowd sourcing experiment that aims to improve autonomous capabilities of space probes, such as landing, obstacle avoidance, and docking. If participating, the app extracts visually salient features from the images made by the drone's camera. The features are then combined with the estimates of the drone's state and uploaded. The data is then used in a research aiming to improve robot navigation.

Visit the main ESA website and you'll be greeted with a 6-minute Rosetta promo movie by a kickass Polish artist... P.S. You can also find the video here. P.P.S It seems I've just discovered a way to hijack old diigo entries ;-)

very nice! "For a start, the wires operate well as switches that by some measures compare well to field effect transistors. For example they allow a million times more current to flow when they are on compared with off when operating at a voltage of about 1.5 V. "[A light effect transistor] can replicate the basic switching function of the modern field effect transistor with competitive (and potentially improved) characteristics," say Marmon and co. But they wires also have entirely new capabilities. The device works as an optical amplifier and can also perform basic logic operations by using two or more laser beams rather than one. That's something a single field effect transistor cannot do."

any idea how the shine the light selectively to such small surfaces?

"Illumination sources consisted of halogen light, 532.016, 441.6, and 325 nm lasers ported through a Horiba LabRAM HR800 confocal Raman system with an internal 632.8 nm laser. Due to limited probe spacing for electrical measurements, all illumination sources were focused through a 50x long working distance (LWD) objective lens (N.A. = 0.50), except 325 nm, which went through a 10x MPLAN objective lens (N.A. = 0.25)." Laser spot size calculated from optical diffraction formula 1.22*lambda/NA

Super lol for all those who abused of the law in their slides / opinions / decisions ..

I used the law in some slides :-)! This sentence is more or less the summary "The end of Moore's law is not a technical issue, it is an economic issue,". As Moore's himself recognized last year, the Moore's law itself is a pretty wild extrapolation of one exponential growth when there were only 5 experimental points. It is remarkable however how the semiconductor industry grabbed this and made every single effort to make it true. This effort was rewarded by turning semiconductor industry into one of the most important industries worldwide. Now these are challenging times indeed, and "when tide is gone, we realize who was swimming naked"...

The "law" is one of the most successful concrete predictions of the technological future... Still very impressive and a lot more long-lived than Moore had probably ever dreamed of :)

"Over the past couple of decades, the research literature has filled up with endless new nature-based metaphors for algorithms. You can find algorithms based on the behaviour of cuckoos, bees, bats, cats, wolves, galaxy formation and black holes. (...) All researchers have been doing is wasting time on developing new approaches that are probably little better than existing ones. And the language of each metaphor then invades the literature, distracting people from using the already sufficiently expressive terminology of mathematics and, above all, working together to find the best way forward." The golden era of fireworks-like algorithm is about to end

Lies, lies, all lies. They will never go away. Papers need to be published.

first science results reported in Nature (as far as I know) from the Yutu-2 and Chang'e mission .... and they look very good!

Sure they are very useful! It will be even better if they manage to fit the data to modeled circulation of the lunar magma ocean that was formed posterior to the "Theia" body collision with Earth. The collision was the cause of the magma ocean in the first place. The question now is how this circulation pattern of the lava-moon "froze" in time upon phase transition to solid. Because, what crystallizes last in sequence, is more rich in "incompatible" with the crystal structure, elements, we might combine data+models to predict their location. Those incompatible tracers are mainly radioactively decaying elements that produce heat (google publications about lunar KREEP elements (potassium (K), rare earth elements(REE), and phosphorus(P)). By knowing where the KREEP is: - we know where to dig for them mining (if they are useful for something, eg. Phosphorus for plants to be grown on the Moon) - we avoid planning to build the future human colony on top of radioactives, of course. The hope is that the Moon, due to lack of plate tectonics, has preserved this "signature of the freezing sequence". Let's see.

thanks Nasia! very interesting comment

advantages: p-bits run on room temperature and are easier to connect than q-bit.

The best paper on transformation optics written ever :-)

Concerning the fabrication... as usual, no idea. I agree that this is the main drawback of MM, and certainly difficult to overcome. I would double check that number, because its value is related with the beam shape of Fig. 1 A. I believe that the simulations are correct, it's just a detail.

wow ... still publishing despite babysitting and new job!!

did you read this one? "When my wife and I started dating she invited me over for dinner at one time. Her kitchen had something called Bauhaus chairs, which are full of holes, approx 5-6 millimeters in diameter in both back and seat. During this lovely dinner I was forced to liberate a small portion of wind and was relieved that I managed to do so very discretely. Only to find that the chair I sat on converted the successful silence into a perfect, and loud, flute note. We were both (luckily) amazed and surprised and I have often wondered what the odds are for something like that happening. We kept the chairs for five years but despite laborious attempts it couldn't be reproduced."

an experiment at the University of Pennsylvania. It might be a bit far-fetched but I thought it might be useful when exploring new planets. Combined with AI the robot would able to assess the terrain and deploy another robot the shape of which would be chosen to best suit its environment. I was thinking of this in the context of exploring places on other planets which are inaccessible by regular rovers (e.g. caves on Mars).

As we are allowed to think ...

Charles Stross... this one was interesting, but I think the best essay he has written in the past few months is this one: How low (power) can you go? -- On the subject of ubiquitous computing devices and urban architecture

Anybody knows them? What mathematic tools are behind their products?

Wouldn't have guessed

Francesco, I missed your comments :) :)

The article came out some time ago of course and was posted here, though the story here is still well written. If you are lazy to read the rel long article, here the summary explanation: The team found that a good half of the force came from heat from the RTGs, which bounced off the back of the spacecraft antenna. The other half came from electrical heat from circuitry in the heart of the spacecraft. Most of that heat was radiated through louvers at the back of the probes, which weren't as well insulated as the rest of their bodies, further contributing to the deceleration.

nice - did not know about it. GTOC on steroids and with loads of cash. concerning this specific challenge and especially the last condition: doesn't this hint towards a flawed design? In addition to maximizing the total power output there are some constraints on the possible movements: Each SARJ and BGA is limited to a maximum angular velocity and to a maximum angular acceleration. Each SAW must produce at least some minimum average power over the orbit (which is different for each SAW). The sequence of positions must be cyclic, so it can be repeated on the next orbit. The maximum amount of BGA rotation is not limited, but exceeding a threshold will result in a score penalty. Some structural members of the SAW mast (called Longerons) have restrictions on how they can be shadowed.

The longerons will expand and contract with exposition to sun (I think whatever the material they are made of). Because you have 4 longerons in a mast, you just need to be carefull that the mast is well balanced, and that the 4 longerons support each other, basically, you need an even number of shadowed longerons, possibly 0 too. I would call this an operational constraint.

They search numerically for initial conditions resulting in periodic orbits. Reminds to me the methods we employed for the "search for invariant relative motion" and which brought us to discover the magic inclinations (47.9 degrees). I wonder what are the implications. In any case nice plots :)

Haven't read in detail, but it's not clear to me what it means exactly. If they were discovered numerically (I assume it means via numerical integration), how can they be sure the orbits are truly periodic?

ridiculous next frontier for patenting ... mathematics!!!!!

should I take these as an indication of news from the bankers concerning your business case?

this would trigger innovation, and kill mathematics! The world is crazy... imagine a mathematician that will have to pay to use a demonstration for his own demonstration... haha. And the interviewed guy in the article say that this would benefit mathematicians !!! what a joke ! And all the schools that will have to pay billions to Euclid's heirs ! This would kill physics too, and all domains that use mathematics as a tool !

Our mission is very simple. We are working towards launching a human being into space. 

Nicholas this is project I mentioned while G&T-ing in Madrid.

space-related kickstarters moving from cubesats to space telescopes. This funding campaign was launched today, and will last for 32 days. They are asking for 1M USD.

"Since the formation of Planetary Resources, our primary goal has been to build technology enabling us to prospect and mine asteroids. We've spent the last year making great leaps in the development of these technologies." - Damn we need to get in touch with these people..!

some of the quotes in there are a bit limit ... :-)

I would well imagine a team at an other space institution, with their own diigo, commenting on that news ... ;p Interesting trend nonetheless. At the NASA Space Apps Challenge, few teams proposed a similar G&C application but for the rover Curiosity... this is certainly a good approach for citizen science.