auxym

As mentioned in the article, reaction wheels are the standard method used to control satellite attitude.

I don't know, I live in eastern Canada, modern cars don't seem to have much of an issue on the handful of -20 to -25 Celsius mornings we get every year, as long as the battery is in good shape.

Even the 2007 Yaris we had up to 2018 never had an issue (after I replaced the dying battery).

Now the -40 C weather they've been having in the prairies recently is a different issue, one I can happily say I don't have any experience with.

REW (free, but not FOSS): https://www.roomeqwizard.com/

A calibrated measurement microphone can be bought for 79$: https://www.minidsp.com/products/acoustic-measurement/umik-1 or https://cross-spectrum.com/measurement/calibrated_umik.html

Here's a frequency response test pitting a coathanger against premium audio cable:

https://www.soundguys.com/cable-myths-reviving-the-coathange...

Spoiler: the difference between the coathanger and the premium cable is probably inaudible, and the difference between anything better than a coathanger (ie, literally any sort of copper wire) and the premium cable is certainly inaudible.

FYI, some members of the Nim community are working on a fork, for apparently similar reasons as OpenD (community-led development). https://github.com/nim-works/nimskull under active development and not ready for general consumption though, from my understanding.

Indeed, and whatever code is used to publish a paper is a prototype, and unlikely to be reused, ever. Sometimes it is, but rarely.

For all embedded purposes, I'd strongly recommend sticking with `--mm:arc` and avoiding cyclical data structures (can't see much of a use for that anyways).

With ARC, you don't need to "run" any runtime GC. ARC is a fully static thing, the reference-counting happens at compile time (static analysis) and the compiler injects (the equivalent of) malloc() and free() calls in the compiled code based on that.

It's great for embedded IMO. You get the performance of manual memory management with the convenience of GC. The only thing to be wary of is that it "hides" a bit when allocation happens. On embedded, you often want to minimize dynamically allocated memory for performance and heap fragmentation reasons, though the latter should be less of an issue with 64 mb of RAM. In nim, you just have to remember that creatin a string, a seq or a `ref object` allocates. So you want to eg. avoid creating and destroying a string repetitively in a loop. Instead create a `var` (allocate a buffer) once, outside the loop, and modify it as needed in the iterations. Everything else in nim (including plain objects, which map to regular C structs) is stack allocated, so ARC doesn't get involved at all.

Further reading:

https://nim-lang.org/blog/2020/10/15/introduction-to-arc-orc...

https://nim-lang.org/docs/mm.html

https://nim-lang.org/docs/destructors.html

https://nim-lang.org/docs/nimc.html#nim-for-embedded-systems

We used them in 10th grade "advanced" math (Canada, I think the equivalent in the US would be AP?). TI-80plus in the early 00's. We didn't have laptops in classes.

Main use case was quadratic equations, which were a significant part of the class. We could plot them to get an intuition of the effect of the parameters. Plot them to visualize the zeros (or the absence of zeros), or the minima/maxima to get intuition on those. Same for finding intersection points of a quadratic function and a line, or two quadratics. We also programmed the quadratic formula in it, to get faster results instead of typing it out each time.

Other parts of the class were trig and stats, from what I remember I don't think we used the graphing/programming much in these parts.

Something like the FSC standards?

https://fsc.org/en/fsc-standards

KFs, and more generally state observer systems, are widely used in the field of control systems.

I know someone with a PhD in control systems, works for an eVTOL startup, and their title is something like "estimation expert" or "estimation specialist". That is, 100% of their job is designing relatively complex KF-like algorithms that are used to estimate the aircraft state (position, pose, velocity, wind conditions, etc) in real time based on a bunch of sensors.

The EMH is a model, and like all models: none are correct, but some are useful (to understand some phenomena).

Sorry for shilling this podcast that I mentioned in another comment in this thread, but they do have very relevant information on this too:

https://rationalreminder.ca/podcast/220

This is an interview with two academic researchers into active fund managers who can indeed beat the market consistently sometimes. One factor why they exist is that they have access to better information than the average individual investor. However, (1) excess returns tend to mostly get absorbed by higher fees and (2) it's very difficult to scale it up, funds who beat the market tend to lose this edge when more funds go into them. Thus, market-beating funds, if they want to maintain their edge, have to severely limit who can invest in the fund and how much they can put into it.

The episode also goes into the effect of security selection (which stocks are picked) vs market timing, which is relevant to TFA.

> If the markets were truly efficient, randomly picking stocks would beat SPX ~50% of the time. Since markets are not super efficient, basic exposure to performance factors (small cap, value, momentum...) puts you at a fairly high likelyhood of beating SPX.

This assumes that the expected return of a single, randomly-picked stock is symmetrically-distributed. It is not, single stock returns are highly skewed and "lottery like". Index returns come from the fact that a small number of stocks do exceptionally well, while most of them do poorly.

This becomes even worse if we talk about timing: stock returns come from relatively short periods of doing really well, if you miss that because you are out of the market for some reason, you lose out on the vast majority of the index return.

Sorry, I don't have specific sources to cite. This comes from stuff I've picked up listening to the Rational Reminder podcast (https://rationalreminder.ca/podcast-directory), which have very well researched episodes as well as guest interviews with leading academic finance researchers. I'll try to dig up the relevant episodes, which do cite sources.

Edit: here is some sources:

1. https://www.dimensional.com/us-en/insights/singled-out-histo...

2. https://assets.jpmprivatebank.com/content/dam/jpm-wm-aem/glo...

Quote from this last one: "[...] around 40% of the time a concentrated position in a single stock experienced negative absolute returns, in which case it would have underperformed a simple position in cash. And around 2/3 of the time, a concentrated position in a single stock would have underperformed a diversified position in the Russell 3000 Index. While the most successful companies generated massive wealth over the long run, only around 10% of all stocks since 1980 met the definition of “megawinners”."

It's effectively a struct with no members.

(Nim compiles to C, so in fact it compiles to exactly that).

Not plugin though, at least not yet. AFAIK the Chrysler Pacifica is the only plugin minivan on the NA market at the moment.

If I recall correctly, lazy symbol resolution, which would allow both circular module imports and order-independent procs, was initially on the roadmap for 2.0. Currently, it was moved to a stretch goal for 2.2.

https://github.com/nim-lang/RFCs/issues/503

Matplotlib is heavily inspired by MATLAB's plotting, no? Its pyplot submodule is a wrapper around the base OO API which is an almost exact clone of matlab.

Trying kbin and lemmy. Both are compatible with each other through activitypub federation (aka fediverse), so choose an instance of either and browse away.

It's still very quiet compared to what reddit was. Not yet enough users to support the niche communities which made reddit special (IMO), but I'm trying to contribute anyways, hopefully building it up a bit.

Losing reddit is sad, the feeling to me is a bit similar to when we lost supernova, then what.cd. An internet jewel that will never be the same again.

I seem to remember N64 joysticks were somewhat fragile. Many of my friends as a kid had controllers with a joystick that had lost all springiness and barely responded to input.

I have not are that on any other controllers, even cheapo xbox360 clone controllers from AliExpress.

I recently read Culture Code, about organizational culture, and it talks about Pixar quite a bit.

It is mentioned that after some failures, Disney purchased Pixar then had Pixar execs, including Ed Catmull, come to Disney to instill a culture similar to the one at Pixar. The story is told as a success, with the films you cite as examples of that.

I also don't normally normally enjoy musicals, but I really liked La La Land.

Not much difference, it's just good to see Arduino coming back as decent competition.

Personally I'm really stoked about the Uno finally getting a 32 bit ARM core. And an M4 at that! I would've thought maybe a M0+ (like the RP Pico) on the Uno and perhaps an M4 on a hypothetical future Mega update.

Good stuff from Arduino. The AVR on the previous Uno revs was getting quite outdated. Simple to use yes, but the Arduino environment mostly abstracts over that and only "power users" ever need to dive into peripheral registers and whatnot (eg to use interrupts).

Found on HNva while ago: https://nobsgames.stavros.io/android/

Indeed.

Plus, I subscribe to about 30 subreddits, most of which pretty niche. Could I replace them with forums? Sure, and I do have fond memories from phpbb forums around the turn of the millenium, even moderating a few as a teen.

But then I'd have to check about 5-10 different forum sites daily, each with subforums for different specific topics. It adds friction.

It's much more convenient just opening reddit whenever I have a few minutes to scroll my feed and see what's up in my niche communities.

Reddit also gives the power to users to create niche communities. R/xbiking comes to mind, which is about a very specific bicycling subculture consisting of using vintage mountain bike frames from the 80s and 90s with a mix of modern and vintage parts to create cool all around bikes... Sort of. Anyways, to my knowledge this subculture did not exist anywhere before Reddit, and I can hardly see how it could have sprung up on bikeforums.net, for example. Petitioning the forums admins for a new subforum for a community that hardly existed would have been difficult, and the sort of posts R/xbiking sees would probably have been closed as offtopic in other subforums. Much easier to create and organically grow a new community on Reddit.

Personally, after being a bit reticent, I am now hopeful for fediverse based solutions (kbin and Lemmy notably) to replace this.

It's mentioned at least in Skunk Works, which is a first hand account from a Lockheed engineer that worked alongside Kelly Johnson during SR71 development.

https://www.goodreads.com/book/show/101438.Skunk_Works

Sounds similar to the "frenglish" that is often heard in Montreal.

Lemmy and kbin are the most similar to Reddit I have seen so far.

kbin appears to be very young and beta-grade at best, though under active development.

Or patents and public disclosure.

Ie, if you're in the process of developing patentable technology or writing a patent, anyone to whom you disclose details needs to be under NDA, otherwise your patent may be refused due to prior public disclosure.

Or so is my understanding anyways, I am not a lawyer.

Tapatalk is/was an attempt at such an aggregation tool for old-school forums. In addition to aggregation, it offered better UX for mobile. I haven't used it in many years though, I'm not sure what it looks like these days.