Ideas page updat­ed

I updat­ed my ideas page. I added an entry about using com­pressed air to auto­mat­i­cal­ly remove snow (or sim­i­lar) from solar cells, and an entry about maybe using heat from ther­mal solar cells to gen­er­ate elec­tric­i­ty at home. I also updat­ed the entry for non-optimal weath­er opti­mized solar cells with a link to a com­pa­ny which seems to do some­thing sim­i­lar (using a lens) to reduce the cost of solar pan­els. To cool down the pho­to­volta­ic cells, the com­pa­ny is using a heat exchang­er to make a com­bined photovoltaic/thermal pan­el. Unfor­tu­nate­ly they are mak­ing an unfair com­par­i­son of the com­bined out­put of this pan­el (the ther­mal pow­er out­put is much high­er than the elec­tric pow­er out­put) with a nor­mal pho­to­volta­ic cell. A nor­mal house­hold needs more elec­tric­i­ty than heat so you do not want to use a lot of such pan­els, but depend­ing on the fea­si­bil­i­ty of my idea about using heat to pro­duce elec­tric­i­ty, such a pan­el could be inter­est­ing.

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Google’s new RE engine

I stum­bled over Google’s new RE engine. Unfor­tu­nate­ly it is not han­dling back­ref­er­ences, so it is not a drop-in replace­ment for the reg­u­lar expres­sions code in FreeB­SD. It has a POSIX mode, but this only seems to be enough for the egrep syn­tax. For peo­ple which need back­ref­er­ences, they refer to the Google Chrome’s RE engine irreg­exp which in turn ref­er­ences a paper from 2007 which is titled Reg­u­lar Expres­sion Match­ing Can Be Sim­ple And Fast.

The tech­niques in the paper can not be applied to the irreg­exp engine, but maybe could help to speed up awk, egrep and sim­i­lar pro­grams.

I think it would be inter­est­ing to com­pare those recent devel­op­ments to what we have in FreeB­SD, and if they are faster, to see if it is pos­si­ble to improve the FreeB­SD imple­men­ta­tion based upon them (either by writ­ing new code, or by import­ing exist­ing code, depend­ing on the cor­re­spond­ing license and the lan­guage the code is writ­ten in).

Maybe a can­di­date for the GSoC?

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