“The Unreasonable Effectiveness of Recurrent #Neural-Networks” for #image-recognition, #NLP language modeling (producing what looks an awful lot like Markov-chain text with slightly better context-free properties), sequential processing for directing attention over an image, etc. Lots of animations and visualizations of RNNs doing their thing. The models are written in #Lua with something called #Torch-7 and run with #GPGPU. Lots of great comments! "unreasonable RNNs"
drawing a graffiti-like #font with #splines using the #method-of-differences.
#Abstract of “#Fasting: molecular mechanisms and clinical applications,” Longo and Mattson 2014. They are super enthusiastic about intermittent fasting!
#paper “Fasting Differentially Modulates the Immunological System: Its Mechanism and Sex Difference” in mice.
“#Levenshtein automata can be simple and fast” and useful for finding potential misspellings (like for a #search-engine, with applications given to #Lucene) in a #trie. #Python with #graphviz: 40 lines of code and good (O(max edit distance) supposedly) worst-case #complexity. #smallisbeautiful #algorithms
The homepage of the Porter Stemmer #NLP stemming algorithm, among the most-widely-used stemming #algorithms, with dozens of implementations. Recommends using the Snowball stemmer instead, except for “IR research work involving stemming where the experiments need to be exactly repeatable”.
Derakhshan’s moving call to #decentralization for the web.
How to tell where someone has clicked on a page in #JS mouse #events because the #DOM sucks, as of 2002, by #ppk. Unfortunately he’s trying to figure out where you clicked on the page, not where you clicked on the canvas, which is what I usually want to know.
How to tell where someone has clicked on a page in #JS mouse #events because the DOM sucks, as of 2015, by #ppk. Again, sadly, he’s getting page X and Y, not canvas X and Y. Also, this covers event properties in general.
Donald #Trump admits to #rape of Ivana Trump but claims a technicality in the #law keeps him safe.
The #myth of Lugh, the carpenter, smith, champion, harper, poet, teller of tales, magician, physician, cup-bearer, and worker in brass, as told by Lady Gregory.
#Geoengineering #startups attempting #carbon-removal to stop #climate-change. (Global Thermostat and Climeworks.)
The lives and gnomai of the eudokimesanton #philosophers, by Diogenes Laertius, including that of #Diogenes of Sinope, the Cynic. In #Greek.
#Introduction to simple, efficient interpreters in #Haskell using the #CEK machine (control, environment, continuation) model of the #lambda-calculus.
Partial order theory for computer scientists: “the fragment of partial order theory most commonly used in computer science”
“Prefix Sums and Their Applications”, Blelloch 93. This is the definitive #paper on #prefix-sum #algorithms as of uh 22 years ago. It mentions specifically a #regular-expression #search-engine and #lexing as two of the applications of prefix sum! I think the “parallel solution of recurrence problems” mentioned here can be applied to #DSP IIR filtering. This is just “Chapter 1” (of what, I have no idea), but it promises more meat in chapters 2, 3, and 4, mostly to do with linked lists and trees.
“Data-Parallel Finite State Machines”: #parallel simulation of #finite-automata that are “up to 3× faster than optimized sequential implementations on a single processor” in #performance due to using #SIMD instructions. Seems to be some tweaks to the #prefix-sum thing Blelloch mentioned in his 1993 #paper, which they call “enumerative computation”? These algorithms are probably crucial to speeding up #CSV parsing.
Rain World: a 2012 2D platformer indie #video-games prototype with a slugcat protagonist, procedurally generated animations, and filtered collages for level backgrounds. Includes some tips on #A* #search #algorithms in tricky situations.
A #UX imitating #Scratch for #OpenSCAD, or rather #OpenJsCad, for designing #3D objects for printing. I can’t try it on my netbook right now because I don't have #WebGL.
#Algorithms for best #performance on a #parallel #prefix-sum in #CUDA for #GPGPU as of 2007.
The Ladner & Fischer 1980 #paper on #parallel #algorithms for #finite-automata using #prefix-sum, with its unnecessary extra N² inefficiency compared to the N lg N in Hillis & Steele 1986. I think, anyway. I haven’t really read the paper.
A survey #paper of #parallel #prefix-sum #algorithms, finding that the Kogge-Stone algorithm is more common in #GPGPU code than Blelloch’s, and with handy diagrams so you can see what they’re talking about! Also they apparently wrote a thing to use #formal-methods to verify different implementations.
Tom Murphy dooming about #collapse as of 2012 because #energy. Specifically he’s worried that an #oil crunch “within the decade” will make #transportation very expensive, which will cause the #economy to collapse, and then we won’t be able to make #photovoltaic solutions. This is causing him a motivational crisis because he worries that his scientific work will be lost in the collapse.
Tom Murphy worrying about economic #collapse from an #energy crunch in 2011, using NREL #EROEI figures about #photovoltaic modules from 2000. From my point of view, a 4-year energy payback time is the same as a 25% limit on the annual economic growth rate: if energy is like super expensive and PV is the only way to get it, then making PV cells will consume nearly all of the energy produced with them, and we can expect the amount of PV power available to double every three years under those circumstances, even if no fossil fuel is available. In 2010 the world produced 31.4 TWh of #solar energy and marketed 148000 TWh of all energy, so about 12 doublings were needed for solar to reach world marketed energy consumption. At three years per doubling, that would be around 2046. The availability of some fossil fuels can only accelerate that trend, under capitalism, anyway. (He makes a good point that a central planner might very easily prefer to devote today’s energy to today's needs instead of investing it to produce returns tomorrow.)
Renewable #energy overview from BP, showing 185.9 TWh consumed in 2014 (21 GW). Germany, China, Italy, Japan, and the US are the leaders, trailed by Spain, and 2013 to 2014 growth was 38.5%, for a doubling time just over two years. In 2007 it was 6.8 TWh (per year; only 0.78 GW), for an average compounded yearly #growth rate of 60%, so it’s slowing down from an #exponential curve, which would be super bad news if this is a normal #logistic diffusion curve.
World marketed #energy consumption was 148000 TWh in 2010 (17000 GW) and 155000 TWh in 2012 (18000 GW).
Expect #collapse to be faster than growth, based on data from Russia and the #Maya collapse.
The #CEK machine in 14 lines of #Prolog. #smallisbeautiful
The story of /r/anarchism on Reddit: “ideological hijacking” by a group of anarcho-feminists. “‘Hijackings’ like this are just the removal of unprincipled exceptions to a widely held moral code that, when consistently interpreted and applied, demands that all communities must be primarily concerned with #social-justice issues.”
Jane Street’s blog post releasing their #Incremental library for #SAC, from 2015-07-18, although they’d apparently been working on it internally for quite a while.
#Arachnid wrote a #reactive programming framework using static analysis and decorators in a few lines of #Python.
Being able to handle datasets bigger than memory is the main reason a lot of people are still using SAS when they would otherwise prefer #Pandas or #R.
#HP brought the world’s first 16-bit NMOS #microprocessor #hardware to market in the 1970s to power the HP 9825A desktop #RPN calculator. #history
getting #ceramics glaze slurry #materials to be #thixotropic typically involves adding a little vinegar or Epsom salt (better for slurries that contain more #clay), but some ceramics processes require deflocculating your glaze slurry or slip to avoid thixotropy. For #slipcasting you normally just partially deflocculate the slip in order to let it remain a bit thixotropic.
discussion of deflocculating #clay #materials by adding acid in order to make them less #thixotropic for #ceramics #slipcasting.
ORNL developed #gelcasting for “technical” #ceramics #materials (including #silicon-nitride) in the 1980s and 1990s, and this is a #popsci overview; apparently Mark Janney, Stephen Nunn, Claudia Walls, and Ogbemi Omatete are recognized as the inventors. Apparently the advantage over slipcasting is that shrinkage is uniform and the green casting is strong enough to be machinable. Initial experiments used methylcellulose, which gels when heated with water, as the gelifying binder, but “multifunctional acrylate” polymers (??) were the binder that made gelcasting practical, followed by water-based #acrylamide, then less-toxic methacrylamide.
Turns out #acrylamide is a (potential) human carcinogen, and the acute fatal dose is a few grams. However, polyacrylamide, a highly water-absorbent plastic, is so nontoxic it’s used in contact lenses and as a subdermal filler. #toxicology
Galip Sarper Koçlar’s master’s thesis #paper on #gelcasting of #alumina #ceramics #materials with #gelatin and #carrageenan gum. He got best results with 5% by weight gelatin, or 1.7% by weight carrageenan, which resulted in significantly lower fired hardness but higher fired compressive strength than the gelatin, and all his trials were with 47–53% alumina, which reached 95.8% after firing at 1550°, and a bit of Dolapix dispersant. 17.5% linear shrinkage. In English, not Turkish, although it’s kind of broken English. The introduction has the best #survey of gelcasting I’ve found so far. Apparently #acrylamide (and, I guess, other similar binders) needs 30–60 minutes to gel in the mold. He also mentions existing “natural gelcasting” processes for technical ceramics using “starch, ovalbumin, chitosan, alginades [sic; should be #alginate], #gelatin, carragenan [sic] gum and [sic] etc.”, and agarose, with the disadvantage being lower green strength.
this lapsed Japanese patent from 2002 talks about making lime plaster (#slaked-lime) #materials sticky and #thixotropic by using 0.1%–5% #carrageenan (dry weight), which is apparently not as sticky as methylcellulose and won’t crack your plaster by absorbing water later. Some carrageenan molecules (κ and ι) gel with metal ions, while others don’t and are therefore more desirable for this. I'm surprised carrageenan will still gel in the insanely alkaline conditions found in lime plaster. It says you can use up to 4% or 5% (or sometimes as little as 2%) before it starts to shrink and crack as it dries. #patents
you can use #gelatin for #casting plaster and similar #materials instead of silicone? For some reason the author mixed 2 parts gelatin, 1 part honey, 2 parts glycerin, 1 part water, and for a mold release, cornstarch or talcum powder.
#Abstract about #Gelcasting 50% (by weight) #alumina #materials with 1% (by weight) #alginate and 1.8% (by volume) calcium phosphate. This seems particularly interesting to me for #3D printing because alginate gels fast when there’s enough ionic calcium present, which can be controlled by temperature.
this chapter of “Novel Colloidal Forming of Ceramics” discusses #gelcasting #alumina #ceramics by adding hexanedioic acid to dechelate calcium ions from calcium phosphate that had been chelated by sodium hexametaphosphate and trisodium citrate, polymerizing #alginate #materials into a gel. The usual song and dance about ball mills, vacuum degassing, dissolving alginate for days, and so on, but basically their main problem was that it was gelling too damn fast, which is why they came up with this chelation nonsense to slow it down.
overview of #alginate #materials, especially as used in food
#3D printing in #alginate by using two nozzles, one for the alginate and one for calcium chloride solution, to “bioprint” artificial organs. I suppose you could also spray alginate onto the surface of a slowly rising calcium-chloride bath to get a very-low-cost, nontoxic version of resin stereolithography, with an inkjet print head substituting for the laser.
an overview of #carrageenan. Apparently to gel it you heat it above 60° to dissolve it and then let it cool with potassium ions (for elastic gels) or calcium ions (for brittle gels). It seems like this might be better suited than alginate for #3D printing, since you could use a single nozzle that keeps the carrageenan solution hot to keep it from gelling. ι carrageenan gels made with calcium are #thixotropic, and used in toothpaste for this reason, as are κ carrageenan gels made with casein.
#Konjac or konnyaku (glucomannan) at 0.5% in water makes a #thixotropic solution, and since it’s nonionic, it's not very pH-sensitive, stable down to pH 3.3. Konjac with xanthan gum in mildly acid food forms a thermoreversible gel up to about 40°, but under alkaline conditions, the gel is heat-stable (up to 200°!!) once it forms after cooling (even at 85°). At pH of 4 to 7, it doesn’t gel by itself, but does synergize with other gums.
information on how to identify #konjac in the lab
#paper on #gelcasting #alumina and zirconia #ceramics #materials with #gelatin and polyethylene spheres to add porosity. Presumably you could use paraffin spheres too, which would be cheaper and maybe improve thixotropy. Something somewhat hydrophilic, not easily water-soluble, and burnable-out might work better still. (Lecithin?)
A #popsci article on #gelcasting #ceramics. Mentions that binder burnout takes “less than a day” as if that’s a short time!
Another master’s thesis #paper on #gelcasting #ceramics in broken English, this one using methacrylamide as the binder.
reinforcing #plaster #materials (including #slaked-lime plaster) with hair, the traditional material, results in problems if you try wet-store it, because the alkaline plaster eats the hair, a problem that would be even worse with glass fiber. (I think this does not apply to calcium sulfate #gypsum plaster of paris.) Various cellulosic materials have been used, and those resist alkaline environments quite a bit better.
Extensive analysis of #gypsum use in agriculture and its effect on soils. Apparently it’s not alkaline.
A #FAQ about #gypsum #plaster. Apparently #gelatin was the traditional material for molding plaster! Lots of great tips, including the crucial, “Do not rinse plaster off in a sink.”
Đức thắng Nguyễn has made #video illustrations of 1700 #mechanical mechanisms over the last 13 years.
10MB catalog of Đức thắng Nguyễn’s #mechanical mechanism #video illustrations, in three PDF files, organized by topic. Including, say, a dozen or so designs for continuously variable transmissions (#cvt), a bunch of negative #stiffness mechanisms, and so on. Entirely rigid bodies as far as I can tell except for the occasional coil or leaf spring.