on #Kalman-filters in #robotics. Doesn’t even mention #particle-filters!
An #ebook on #Kalman-filters as a series of #IPython notebooks that does mention #particle-filters a bit. #cc-by.
HN discussion about #Kalman-filters
A #paper about exploiting #virtualization to do “off-host” memory-scanning of guest VM memory for #malware. #censorship
6,500 words on Daniel Leese’s fascinating book #Mao Cult: Rhetoric and Ritual in #China’s #Cultural-Revolution [Cambridge University Press, 2011], by someone who is no expert on Chinese history #toread
Principia Mathematica #ebook incomplete
30-minute-delayed #intraday #trading #data in #python from Google Finance (5-minute OHLCV bars; seems to be a 768-bar-per-request limit)
#visualization of #time-series #quantiles (on #space-travel #predictions)
#examples of how to do #visualization of small multiples with #matplotlib pyplot in #Python, using subplots and iterating over the axes in its return value
Dan #Gelbart’s brief autobiography for SPIE, focusing on his work at MDA, Cymbolic, and Creo. Substitutes “aerial density” for “areal density”.
A tech note from cylindrical-lens manufacturer Newport: circularizing the beam from a #laser diode with two cylindrical #lenses with different focal lengths and perpendicular axes, since laser diodes have elliptical divergence. Why has nobody done this for regular magnification? Cylindrical lenses are dramatically easier to manufacture than spherical lenses! There must be a reason it won’t work.
Whoa, you can focus #X-rays up to 40 kEv with a series of concave #lenses made of aluminum or beryllium (negative refractive index!), like, say, a block of aluminum with a series of holes drilled in it, or a series of prisms (“saw-tooth lens”; not sure this isn’t just a Fresnel) of silicon, plastic, or lithium. If stimulated or induced gamma emission from metastable nuclear isomers (like they were trying to do with #hafnium) is possible at all, this might be the way to do it.
The 1997 “high energy density explosives” report JSR-97-110 from MITRE to DARPA concluding that induced gamma emission from metastable #hafnium nuclear isomers was not possible. The relevant part is “Energeric [sic] materials from radioisotope reactions” on the 14th page (p.13), but it doesn’t go into any details. Indeed, it’s basically just a complaint that there no details are known.
Designing a #flexure bearing with #Solidworks, simulating it with #FEA, and #machining it out of steel on a waterjet cutter. Lots of tips in the comment thread on #mecheng design.
PowerPoint slides on how to design a #flexure system. #mecheng
Commercially sold #flexures.
Advantages of Heli-Cal’s machined #spring helical #flexures over some other kinds of couplings.
negative thermal coefficients of expansion (#TCE) in normal temperature ranges are found in and water below 4°, but few other common #materials.
Roderic Lakes’s #bibliography on composite #metamaterials that can have either negative or colossal thermal coefficients of expansion (#TCE) even if their components don’t. This is potentially useful for making nanometrically-precise #flexures without resorting to exotic materials like #Invar or maybe even metals.
A short, clear-seeming #paper about #metamaterials with tunable #TCE. #toread
“By incorporating constituents of negative #stiffness [elasticity] in structures and composites, one can attain extremely high values of mechanical damping, stiffness considered as a viscoelastic modulus, of thermal expansion, or of other physical properties. Negative stiffness is of itself usually unstable but can be stabilized by incorporation in heterogeneous structures or composites.” #metamaterials #bibliography
A company promoting negative-#stiffness #metamaterials (or “mechanisms”) for #vibration isolation, replacing air tables.
A #paper on negative-#stiffness #metamaterials (“structures”) through “constrained bistable structures” #3D printed in nylon with #SLS. The figures are at the end. Related to #Merkle’s buckling-spring #mechanical logic.
A #popsci explanation of negative-#stiffness #metamaterials or structures, with an #interview.
A 2011 patent application for negative-#stiffness #seismic protection. #patents
Very brief negative-#TCE #metamaterials introduction.
13-page overview #paper of negative-#TCE materials (including cubic zirconium tungstate and perovskites) without mentioning metamaterials at all!
Another overview #paper of negative-#TCE materials, again without mentioning metamaterials at all!
Dan #Gelbart’s brief autobiography for SPIE.