Hi, In aviation, Voronoi diagrams are superimposed on oceanic plotting charts to identify the nearest airfield for in-flight diversion as an aircraft progresses through its flight plan. https://en.wikipedia.org/wiki/Voronoi_diagram#Engineering
https://en.wikipedia.org/wiki/Zatocoding is a 1940's method of selecting index cards based on their perimeter having holes, some of which are cut through. Rather than H holes representing S subjects in a 1:1 mapping, it allows S>H by having each subject be indicated by cutting a pattern of more than one hole. Some subjects may overlap, giving false positives, but the probability of this can be adjusted. The https://en.wikipedia.org/wiki/Bloom_filter used in programming is related. A https://en.wikipedia.org/wiki/Ghost_word is a deliberate error to catch copyright infringement. Maps have https://en.wikipedia.org/wiki/Trap_street. Both forms of https://en.wikipedia.org/wiki/Fictitious_entry. Laser printers watermark printing to identify the individual printer. https://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots There was a mention of a similar technique for videos to track 4K source being HD recorded; anyone know the name? For audio, there's https://en.wikipedia.org/wiki/Cinavia Powers of two in imperial units; halving and quartering is easy. $ units -1v usgallon fluiddram usgallon = 1024 fluiddram $ set usgallon usquart uspint usgill usfluidounce fluiddram $ f=$1; shift $ while (($#)); do units -1v $f $1; f=$1; shift; done usgallon = 4 usquart usquart = 2 uspint uspint = 4 usgill usgill = 4 usfluidounce usfluidounce = 8 fluiddram $ Python's Coverage.py can test more than if every statement is executed at least once. https://coverage.readthedocs.io/en/coverage-4.4.1/branch.html Telegu is the third most-widely spoken language in India. They write in decimal before the decimal point, and base 4 after. But they don't write the point, instead having distinct symbols for 1/4, 1/2, and 3/4, but for 0 they re-use the symbol from integers. In 789½¼¾ it's clear the transition from integer to fraction is after the 9, but 7890½¼¾ is ambiguous because the point might be either side of the 0. Their solution is to have a second set of base-4 symbols, say 0¼½¾ for the first set, and abcd for the second. The first set is used for the even positions, and the second set for the odd ones. 7890½a¾ and 789a½b¾ are now unambiguous because you can never have `.0', and it throws in a little bit of error detection against putting the point in the wrong place. Though I don't know if that was a happy accident. https://en.wikipedia.org/wiki/Telugu_script#Numerals Cheers, Ralph. -- Next meeting: Bournemouth, Tuesday, 2017-08-01 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
