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Ask HN: What's the hardest problem you've ever solved?

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Re: Ask HN: What's the hardest problem you've ever solved?

#231

Post by uxcolumbo »

btiown442 wrote: post #70
uxcolumbo wrote: post #62

Earlier quoted context omitted.

How did you approach this problem and solve it?

I'll give you a hint. Download the image. Because it is PNG that means it is lossless... Zoom in very closely on the top row of pixels above the redacted area and you may discover you have all that you need...

Thanks. I already did that, but there were quite a few letters that were completely covered.

Programming isnt' my day job - but I have an interest in it, so was curious to see what tools / approach you used to automate this and whether it was fully automated or whether your solution recovered the partially covered letters and your 'wetware' recovered the rest ;)

Cyph0n already provided an approach, which you confirmed - so thanks again.

Re: Ask HN: What's the hardest problem you've ever solved?

#232

Post by smadge »

IloveHN84 wrote: post #218

Recognizing face expressions of babies born before the expected date and put in incubators with oxygen masks. The problem is really hard and the collection of video material available prevents the usage of machine learning techniques, so old school algorithms perform much much better.

Can you elaborate more as to why you possibly would want to automate the facial recognition of prematurely born babies?

Re: Ask HN: What's the hardest problem you've ever solved?

#233

Post by [deleted] »

jjjensen90 wrote: post #156

I once told a room mate in college I would repair their laptop's charging port if they were willing to pay more per month on 50 megabit internet (this was a lot of bandwidth back then). I ordered a new port online, waited for it to come, then spent like 12 hours trying to get the factory solder out of the original port. I ended up accidentally frying part of the power board. By this time it was the middle of the nigh…

[deleted]

Re: Ask HN: What's the hardest problem you've ever solved?

#234

Post by smadge »

toredash wrote: post #47

I'm 33 now. Ill come back in 20Y time. I don't believe I've encountered my hardest challenge yet

I would love to know what you say when someone asks you where you would prefer to eat out. I’m imagining something like “the tastebuds attached to my mind have not and can not experience the entire range of culinary experiences that humanity has and will produce so I can not answer your question.”

Re: Ask HN: What's the hardest problem you've ever solved?

#235

Post by MRD85 »

jakelazaroff wrote: post #203
twtw wrote: post #146

Earlier quoted context omitted.

There's more to exams than memorization too, and cheating because you don't like memorization is childish. If the exams really test only memorization, drop the class.

If a particular exam has more to it than memorization, then even open book you shouldn't be able to ace it without knowing the material!

I dislike open book exams so much that I took nothing into my last one. It was a unit without much memorisation that focused much more heavily on applying concepts, and I feel that having it as open book was a trap for ill-prepared students.

Re: Ask HN: What's the hardest problem you've ever solved?

#236

Post by umichguy »

herodotus wrote: post #197

When I was a CS prof, many, many years ago, our undergraduate lab had Macs with floppy disks. I asked the University to pay for installing 10MB Hard Drives in the Macs. I was asked to present my case to the deans council. At the meeting, I said that the students used the floppy to load their development environment. I said that, with a hard drive, it took 10 secs to load and be ready. With the floppy, I said it took…

I have to steal that idea next time someone talks about time delays and says "it's not a big deal!"

Awesome!

Re: Ask HN: What's the hardest problem you've ever solved?

#237

Post by yuchi »

Not _the_ hardest, but among them. Back to 2011~12, cross-platform mobile application development with Titanium SDK (JavaScript).

We have this ~50K sloc application which has several performance bottlenecks. At the time connecting the Chrome Inspector was not a thing. There was a half functional profiler in the paid version of the platform, but it was cluncky and the UI simply unusable (the whole IDE was a customized Eclipse distro).

Since at the time ES6 definitely was not a thing yet, everyone rolled their own class system in projects. In our case the OOP library was more or less Backbone’s, with the typical Child = Parent.extend({ ... }).

This was a godsend: I had a place for every class definition of our codebase, and there I placed an hook which wrapped every damn method of every class with profiling instrumentations.

I then built a small profiling UI (shake the device to start/stop collecting + profiling chart in the logs) and we were good to go.

The funny thing is that I never actually used a profiler before that, so I literally re-invented it from the ground up — only having a collegue of mine staring at the results and saying «what a nice profiler you built over night!».

Only then I started looking at real profilers and introducing “correct” features in my own: real time, self time, flame chart.

A nice memory of simpler times.

Re: Ask HN: What's the hardest problem you've ever solved?

#238

Post by rassibassi »

I'm about to finish my PhD in the field of optical communications and applied machine learning to increase the data rate. More specifically, I used an autoencoder with an embedded fiber channel model, to learn something called a geometric constellation shape or modulation format. (if you ever heard of QAM then you're on the right track, you can think of it as a modern Morse code for transmitting bits) Thereafter, we took the learned constellations to the lab and conducted an experiment, transmitting the learned constellations through actual fiber. I've learned so much during the whole process

Although, the gains are marginal, I like the method a lot since it combines physics (nonlinear schroedinger equation derived fiber channel model), information theory (optimizing for mutual information) and machine learning. It wouldn't have been possible without the people who published the fiber channel model, my colleagues and in particular the colleagues who could help me in the lab.

The debugging was hell, there are so many dimensions where stuff can go wrong (besides the usual bugs): physical parameters with the wrong unit, the implementation of the fiber model in tensorflow, the machine learning parts with its training process. Plus the things that can go wrong in the lab.

There are still pieces where I'm not 100% sure, and would love to speak to someone with some background in autoencoders.

I've open sourced the autoencoder and the fiber channel model, checkout my github with the same username as here!

Re: Ask HN: What's the hardest problem you've ever solved?

#240

Post by zwischenzug »

How to reduce time spent on incidents that were somewhat similar when managing an SRE team. It took seven months of full-time work writing documentation to get off the ground.

I wrote about it here:

https://zwischenzugs.com/2017/04/04/things-i-learned-managin...

The hard bit of it was the leap of faith - I had to stop working on live issues to invest the time in getting the documentation to critical mass. Then we had to get the process right to maintain their usefulness. It resulted in _massive_ savings.

It also inspired this, which I've just started (so very early stages):

https://therunbooks.com/doku.php

eg

https://therunbooks.com/doku.php?id=networking:dns-lookup-fa...

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