Ask HN: What weird or hard problems are you trying to solve? • Hacker News Board

Re: Ask HN: What weird or hard problems are you trying to solve?

#721

Post by shezi » Mon, Jul 06, 2020, 5:06 PM UTC

hazeii wrote: post #647

shezi wrote: post #500

Earlier quoted context omitted.

Indeed, manufacturing is hardly a problem in the software world. =) Maybe get it laser engraved into aluminium and mount it... somewhere? Grey code is essentially a more robust spiral pattern, so that's the same idea. What if you put a roll sensor on the chain instead and infer crank angle from that? Chain slip is rare enough not to worry about it, right? You'd also have more space and could use off the shelf compone…

Nice idea on the laser engraving, maybe we could use that inside the bottom bracket - thanks. We have considered the chain, trouble is both chains and chainrings wear and often cranks/rings aren't terribly-well centred (as fixed gear bike riders know, from variations in chain slack). For the gravity part we've tested a range of accelerometers; vibration is quite an issue though. Thanks for the interest!

Definitely do a writeup for HN when you find a suitable solution!

Re: Ask HN: What weird or hard problems are you trying to solve?

#722

Post by ricg » Mon, Jul 06, 2020, 5:29 PM UTC

biztos wrote: post #695

ricg wrote: post #681

Earlier quoted context omitted.

I'm tackling this problem, too! My focus is on data-longevity so everything is based on simple files and folders. The idea is that the app "understands" the structure of the content. A bit like a combination of a notebook, Xcode, a calendar, and Wolfram Alpha :) Bi-directional links and timestamps are working already so implementing a "Zettelkasten" should be possible with the current version. If you're interested, t…

I very much like the idea of the hierarchy and the content just being the file system. I’m less excited about the connection to Zettelkasten because that smells of fad. If there were an app that would make useful sense out of a few tens of gigabytes of stuff kept in a plain folder hierarchy, I’d be a potential customer. In a way Dropbox tries to do this, and it’s better than nothing (for me) but I still wish for some…

I started working on the app way before Zettelkasten became a thing. My goal is to not force a specific workflow. If you would like to use it as Zettelkasten, it'll work. If you prefer a different system, you can have the app adapt to your needs. It's all just files & folders underneath, only the representation varies.

I'm curious about your folder hierarchy. What kind of files do you keep there to get to tens of gigabytes and what type of knowledge would you like to extract/what type of connections to form?

I'm currently at about 100 MB for roughly 1,400 individual notes (text and images).

Re: Ask HN: What weird or hard problems are you trying to solve?

#723

Post by jaclaz » Mon, Jul 06, 2020, 5:31 PM UTC

jawns wrote: post #170

I hope this counts as weird enough ... PROBLEM: If time travelers from the future were to visit you, it would be difficult for them to quickly prove their authenticity. SOLUTION: Temporal passwords. At the start of each year, you devise a new password. You commit the password to memory, but you never write it down or divulge it to anyone until Dec. 31, when you submit it to the Temporal Password Registry, which publi…

What if the time traveler arrives today and tells you - as gently as possible - that he doesn't know your 2020 password because you didn't (technically couldn't) communicate it on Dec. 31 2020?

Re: Ask HN: What weird or hard problems are you trying to solve?

#724

Post by jon_richards » Mon, Jul 06, 2020, 5:52 PM UTC

If you repeatedly add 2 and then divide by 2, you approach the number 2.

If you repeatedly flip a coin to either add 2 or divide by 2, what distribution do you approach?

If you have a distribution, what random processes are identities for that distribution? Which are stable? Which will reproduce the distribution from any starting distribution?

It’s related to matrix kernels, but it’s hard to generalize to continuous numbers. I spent a while looking into it years ago and couldn’t find much.

My goal was to eventually take it a step farther and create simple stochastic functions for certain behaviors, such as bistable switches, memory registers, etc.

Re: Ask HN: What weird or hard problems are you trying to solve?

#725

Post by dredmorbius » Mon, Jul 06, 2020, 6:09 PM UTC

j4pe wrote: post #550

Why don't gig workers just work for themselves? Gig apps are basically trivial to engineer in 2020 until they get scaling problems, largely due to the contributions of the open source community. It would be nice if there were also open source tools for people's gig businesses, so they didn't have to sell their labor through a company extracting such a heavy rent.

Reading through Charles Perrow's Complex Organizations I was intrigued and amused by his question: why does capital hire labour and not vice versa?

Unfortunately that's not an answer he pursues in the book, though others do, apparently.

Re: Ask HN: What weird or hard problems are you trying to solve?

#726

Post by dredmorbius » Mon, Jul 06, 2020, 6:12 PM UTC

aerovistae wrote: post #119

Telling where the output of an individual stdout print statement ends and the next one begins, so that I could color code my terminal with alternating colors to more easily tell apart individual log messages from a running process by visual differentiation. Turns out this is impossible! Aside from time passing in between outputs, there's no way to tell. It's just a continuous byte stream with no terminating character…

Terminal driver + clock + colour-coding? Strace w/ individual write() instructions identified? DTrace?

Re: Ask HN: What weird or hard problems are you trying to solve?

#727

Post by dredmorbius » Mon, Jul 06, 2020, 6:13 PM UTC

ggerganov wrote: post #523

Working on an algorithm for recovering the text you type just by analyzing the keyboard sound captured through the computer's mic (i.e. acoustic eavesdropping). The hard part is doing it without having train data for the keyboard.

For which TLA/APT?

Re: Ask HN: What weird or hard problems are you trying to solve?

#728

Post by DavidPeiffer » Mon, Jul 06, 2020, 6:19 PM UTC

hazeii wrote: post #649

DavidPeiffer wrote: post #349

Earlier quoted context omitted.

Brainstorm here - could you put a number of lower resolution encoders firmly on the same shaft? The theory would be they'll all pulse on slightly different but consistent phases. Simple example, an encoder is capable of 60 degree resolution. I'll mount 5 of these which will all have some variation in phase, and I'd average out to having 12 degree resolution, with variation that could be modeled statistically. Concept…

Interesting, but I think we're run out of space. Sort of related, we've been considering how we can gut an optical mouse and use the sensor from them. The idea is broadly similar, basically learn the pattern around one revolution and work out where we are in it.

Do you need the data in real time, or can you complete a biking session then process the data?

Re: Ask HN: What weird or hard problems are you trying to solve?

#729

Post by mcphage » Mon, Jul 06, 2020, 6:25 PM UTC

jon_richards wrote: post #724

If you repeatedly add 2 and then divide by 2, you approach the number 2. If you repeatedly flip a coin to either add 2 or divide by 2, what distribution do you approach? If you have a distribution, what random processes are identities for that distribution? Which are stable? Which will reproduce the distribution from any starting distribution? It’s related to matrix kernels, but it’s hard to generalize to continuous…

I would guess that you still get to 2—because the more times you add 2, the greater the impact of dividing by 2, and the more times you divide by 2, the greater the impact of adding 2. Is that the case?

Re: Ask HN: What weird or hard problems are you trying to solve?

#730

Post by ilovetux » Mon, Jul 06, 2020, 6:36 PM UTC

alexyz12 wrote: post #392

I am building a database for human movement. Right now each exercise or pose or movement is indexed by its name - Downward dog, squat, handstand, etc. But this gets confusing when multiple names apply to the same movement. The true identifier is the motion of your limbs in space. I want to encode that motion/position so that if you try and upload L-sit handstand and also L-sit, it tells you that you are try to upload…

What is your motivation here?

I like the idea, but I'm curious what sort of things you are hoping to accomplish.

For instance is human deformity important? Do you want to take into account mild to severe birth defects or dismemberment? How about things like severe burn scars or other medical conditions which can limit maneuverability?