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Cake day: July 1st, 2023

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  • the_sisko@startrek.websitetoMemes@lemmy.mlEVs
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    1 year ago

    Yeah, but they require somewhere in the neighborhood of a thousand pounds of batteries to do so. Some of the more egregious ones need multiple thousands, e.g. the electric hummer whose battery alone is heavier than an ICE Honda Civic. Whereas a dozen gallons of gasoline (roughly 72lbs at 6lb/gal) can power that same ICE Civic for a nearly equivalent range, while causing much less wear & tear on the roads, and likely releasing less tire particulates due to the reduced weight. Of course it still releases CO2 and other nasties…

    But yeah, the energy density of EVs is still super bad. It’s just “good enough” that we’re making it work.


  • the_sisko@startrek.websitetoMemes@lemmy.mlEVs
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    1 year ago

    As I understand it, the big issue is energy density? A tank of gasoline takes you quite far compared to an equivalent tank of hydrogen.

    And don’t get me wrong, lithium batteries are super bad at this too, but I do think that has been a limiting factor for H cars.

    And then there’s the whole tire dust issue which is definitely a conversation worth having.



  • A classic use for them is spam filtering.

    Suppose you have a set of spam detection systems/rules which are somewhat expensive to execute, eg a ML model or keyword blocklist. Spam tends to come in waves, and frequently it can be as simple as reposting the same message dozens of times.

    Once your systems determine a piece of content is spam (or you manually flag content), it’s a good idea to insert the content into a bloom filter. This means that future posts of the identical content will be flagged without needing to execute the expensive checks, especially if there’s a surge of content stressing your systems.

    Since it’s probabilistic, you can’t use this unless you have some sort of manual reviewing queue or system, as it’s possible for false positives to be flagged. However, you can also run more intensive checks once you’ve flagged content, to detect false positives.

    The false positives can also be a feature, not a bug: with careful choice of hash functions, your bloom filter can actually detect slightly modified content, since most of the hashes may still be the same.

    I’ve worked at companies which use this strategy so it’s very real world.





  • They probably know what it is, but it’s a bad point if they’re trying to paint DAGs as esoteric CS stuff for the average programmer. I needed to use a topological sort for work coding 2 weeks ago, and any time you’re using a build system, even as simple as Make, you’re using DAGs. Acting like it’s a tough concept makes me wonder why I should accept the rest of the argument.

    Can’t say I have a strong feeling about Gradle though 🤷‍♀️


  • It’s a cathartic, but not particularly productive vent.

    Yes, there are stupid lines of time.sleep(1) written in some tests and codebases. But also, there are test setUp() methods which do expensive work per-test, so that the runtime grew too fast with the number of tests. There are situations where there was a smarter algorithm and the original author said “fuck it” and did the N^2 one. There are container-oriented workflows that take a long time to spin up in order to run the same tests. There are stupid DNS resolution timeouts because you didn’t realize that the third-party library you used would try to connect to an API which is not reachable in your test environment… And the list goes on…

    I feel like it’s the “easy way out” to create some boogeyman, the stupid engineer who writes slow, shitty code. I think it’s far more likely that these issues come about because a capable person wrote software under one set of assumptions, and then the assumptions changed, and now the code is slow because the assumptions were violated. There’s no bad guy here, just people doing their best.