Merged compressed-sensing onto compressive-sensing because there are many more compressive-sensing than compressed-sensing questions (88 vs 16) and all 16 compressed-sensing are double-tagged with compressive-sensing.
Also made compressed-sensing a synonym of compressive-sensing, it shouldn't reappear.
As I am studying dimension reduction methods, @OlliNiemitalo answer triggered my curiosity. I pushed the study to rank 30, and the answer/reputation graph looks like:
No drastic change in the trend. However, more points cluster at the bottom. So I tried with other easy to reach variables: Reputation, #Month (of presence), #Answers, #Questions, #...
You're right, these are synonymous.
I've created a synonym suggestion, and users with a few answers on the tag can vote for it.
I believe since this is really just a matter of expanding an acronym, a moderator might be able to expedite the process.
So far, we'd have:
signal-processing (which probably is already blacklisted)
dsp (which probably is already blacklisted)
We might want to:
replace ~-processing with just "~"
Certainly, that is something we could do. However, I think we must remember to avoid questions specific to Mathematica. There is a topic about it.
As for mass tagging, I am not sure if it's possible. I would have to check on that one.
Anyway, I've created a tag so feel free to use it. I've been thinking whether to use wolfram/wolfram-language, but ...
OK, I've made the change you suggest.
Older Answer Below
I'd be tempted to go the other way: keep adc and dac and make the longer forms synonyms. Mainly because the shorter forms include "c" (for convertor), and adding that to the longer forms would make them a little long.
Cleaning tags or giving them some distinct content is a good idea. However, I have the feeling that algorithms, reference-request, measurement are useful to me, unless you propose a replacement? I may have added those tags to first posts, or when editing.
I believe that tags should be considered by the relations, with respect to antonyms, dual, or ...