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kctess5

528 karma · joined June 23, 2014

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kctess5··on Drone Uses AI and 11,500 Crashes to Learn How to Fly
No worries :) the drone basically generates a big dataset of "crashing" and "not crashing" video clips from the camera. It then feeds all that into a convolutional neural net, which can (after training is complete) give control decisions based on the camera which avoid obstacles. This is very "black box" in the sense that it's hard to say exactly how the system is working.

The car, on the other hand, uses hand written algorithms to forward simulate various controls. Based on the forward simulations, it can pick controls which are predicted to give good results. Forward simulation relies on a model of how the car reacts to any possible control. However, this model is complicated because of the nonlinear dynamics going on (inertia, wheel slip, etc). Therefore, they use ml techniques to identify the model.

kctess5··on Drone Uses AI and 11,500 Crashes to Learn How to Fly
That's not exactly what the car in [1] does. They use stochastic optimal control methods, which are more domain specific. They perform forward simulation on a lot of trajectories and effectively pick a good one. They also use localization so control is based more on current position than sensor inputs. The machine learning component is the dynamics model identifications - determining how the car reacts to control inputs. The model is basically a complicated function with a few inputs and outputs, which tend to be smoothly varying, so ml techniques work very well. This is fairly standard in model predictive control since empirical motion models tend to outperform ones that are physics based.

Edit: looking at the paper, they apparently use many physics based models of the car as a basis, but then use ml to mix the models together.

kctess5··on Iceland drills 4.7 km down into volcano to tap clean energy
The bird thing is not as big of a deal as some seem to think. Wind turbines kill a couple hundred thousand birds each year [1]. In contrast, cats kill hundreds of millions of birds each year [2]. People still like cats. I also don't think the noise concern is a reason to discount wind turbines.

Of course, dirty alternatives have their own toll on wildlife.

1. http://www.smithsonianmag.com/smart-news/how-many-birds-do-w... 2. https://www.sciencenews.org/article/cats-kill-more-one-billi...

kctess5··on Apple to slice iPhone production 10% due to sluggish sales
I watched "The Last Kingdom" from BBC (which I recommend) and it made me want to know more about 9th century England. So far the book "Alfred the Great: the man who made England" by Justin Pollard has been fantastic if you're into that kind of thing. It's very well researched and historically accurate but not overly dry, Pollard makes a point of not including too many footnotes in the book as many of the more academically targeted books do.
kctess5··on Apple to slice iPhone production 10% due to sluggish sales
True! I just read about the "decimation of Aethelwulf" - the ninth century king of Wessex (current Great Britain) gave away a tenth of his empire in order to secure the kingdom during his pilgrimage to Rome.

https://en.m.wikipedia.org/wiki/Æthelwulf#Decimation_Charter...

kctess5··on 'All I wanted to do is build a house' (2010)
Reminds me of when a family friend of mine (a professor of civil engineering) built his own barn on his property. He got permits and did everything the ordained way, but still got hassled over tons of details. The inspector almost couldn't grasp the idea that the tens of thousands of stainless steel screws he had bought and used significantly exceeded the specs of the nails required by code. He did manage to persevere eventually.
kctess5··on Ask HN: What Are the Best Current Methods to Delete Yourself from the Internet?
Yeah that was my reasoning. The salted hash would be an easy way to implement single-thread username consistency.

Edit: for better readability it could be further mapped into a table of human readable handles, similar to how Google does the "Anonymous Lemur" thing in gDocs.

kctess5··on Ask HN: What Are the Best Current Methods to Delete Yourself from the Internet?
Is that so bad? Granted maybe it's annoying looking at old threads, but as a user, the ability to go through and remove old and potentially regrettable posts is quite welcome.

Maybe a good compromise would be to remove the user information after a certain time period (~2 years). Hashing the username salted with the post title would be a decent way of systematically respecting user privacy while also keeping old threads readable. I wouldn't mind if HN did this.

kctess5··on World Energy Hits a Turning Point: Solar That's Cheaper Than Wind
I'm not sure, but that will never happen unfortunately. The support infrastructure always comes with cost.
kctess5··on Interns in tech make more than workers in most occupations
It was GS
kctess5··on Interns in tech make more than workers in most occupations
I agree. Interns also generally receive no extended benefits like 401(k), stock, medical, and so on, so the comparison isn't very fair in terms of total comp.
kctess5··on Interns in tech make more than workers in most occupations
I've had several big name tech internships, and I got an internship offer from a bank to do tech work. The bank offered around 2/3rd the comp with significantly worse benefits, which surprised me considering that a) they were in NYC b) they were a big name and c) they approached me, not the other way around. Not sure if they pay the trader type interns more...
kctess5··on Criminals can guess Visa number and security code in six seconds, experts find
The expected value of both strategies is to have 1 success, but they have different variance. The first strategy has variance of 0.99, and the second strategy has variance 0. The chance of n out of 100 hits with the first strategy is: binomial(100,n) x 0.01^n x 0.99^(100-n)

edit: asterisks as multiplication signs => italics

kctess5··on Ask HN: What's your dev machine setup?
I built a desktop with a quad core i5, 16gb ram, a GTX970, an Intel SSD, and around 2tb of spinning disk storage. The whole build cost around $700 and it's a very fast machine. I also have 2x 1440p 25" monitors, a mechanical keyboard, and recently added a (normal looking) gaming mouse. I use it primarily for programming/research and occasionally games/oculus rift. Also makes a great web server.

I run Ubunutu, with i3 window manager. I really like this combo after some personalization. It's very stable, and lightweight. I also have two Windows versions and a secondary Linux installation which come in handy.

I also have a 2013 15" rMBP of which I think very highly. I can mount my 2tb of desktop storage, and my SSD as a network drive on the MacBook for sharing files. I also use SSH to run intensive scripts (sometimes GPU stuff) on the desktop.

10/10 would recommend this setup

kctess5··on Scientist discovers particular seaweed nearly eliminates cow methane emissions
Assuming there is a law. I think we can already detect methane well enough to know that cows make a lot of it.

You don't want to make the law something they must "escape" from, but rather something they can profit from by not polluting. Like tax credits.

kctess5··on An Alarm Designer on How to Annoy People in the Most Effective Ways
Maybe it can backfire and you'll subconsciously silence your cell phone during actual calls.
kctess5··on Enzymes from nine organisms combined to create new pathway to use CO2
That would be an interesting compiler project.
kctess5··on SpaceX FCC Application for over 4000 Internet Satellites
Unless I'm mistaken, many founders do give up control to their share holders.
kctess5··on SpaceX FCC Application for over 4000 Internet Satellites
And of course after that, Prime Plus which includes a lease on solar panels and home batteries.
kctess5··on Ask HN: What simple tools or products are you most proud of making?
Thanks! I had not seen that before but it looks nifty.
kctess5··on Ask HN: What simple tools or products are you most proud of making?
It's not totally unique, but I made a simple tool I call "watch" that runs terminal commands on file save. You specify a file glob and a command and it runs the command whenever a globed file changes. Also has a few handy flags. I use it ever day to automate my file save->compile->run workflow. It's amazing how much time you save by never having to up-arrow/enter a terminal after every save. Been meaning to update it to use file hooks instead of polling but it works.

https://github.com/kctess5/file_watcher

kctess5··on A Lost World of Shipwrecks Is Found
I believe that photogrammetry can reconstruct 3D geometry, especially with the help of range sensors like the article mentions. The process results in 3D information like triangle meshes in addition to 2d images.
kctess5··on Global warming disaster could suffocate life on Earth (2015)
Nature found a great way to both scrub and sequester CO2, with O2 as a waste product. Unfortunately we haven't exactly been investing in that technology.

[1] https://en.m.wikipedia.org/wiki/Deforestation

kctess5··on A Method I’ve Used to Eliminate Bad Tech Hires
In some sense many companies do this via 3 month internships. They're basically just low cost future employee vetting opportunities. Of course, they are generally limited to college students.
kctess5··on Offshore Wind Farms Don’t Harm Marine Life
It's not the main point of this article, but I frequently see sources mentioning wind turbines as a cause of bird deaths. Clearly, it's true. Wind turbines may kill over half a million birds per year in the US[1]. That said, apparently cars and other factors like window strikes against stationary buildings, cats, cell towers, and electric wires kill orders of magnitude more birds[2]. Big numbers sound horrible without perspective...

[1] http://onlinelibrary.wiley.com/doi/10.1002/wsb.260/abstract [2] http://www.sibleyguides.com/conservation/causes-of-bird-mort...

kctess5··on Formation of Tesla Advanced Automation Germany
As to... buy a German engineering company?
kctess5··on Supercapacitors are now carbon-free and more powerful
Classic modern reporting - doesn't link to the source or even cite the paper.

Here's the source: http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat476...

Web version: http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat47...

kctess5··on On the road with the 13-inch MacBook Pro
That has been my experience. I have noticed that my mechanical keyboard is much gentler and less likely to induce RSI relate pain because I almost never have hard impacts due to bottoming the keys out. On my MacBook (2013 15" rMBP) it's a different story.
kctess5··on Ask HN: How to escape front end development?
I am still in college (masters student) but have done a good bit of web dev both as a freelancer and at internships. I discovered after a while that it is not what I want to do long term, and have since tried to move away from front end.

I think the answer largely lies in where you have the interest and willingness to learn new tech. Moving to full stack would probably be an easy transition, as knowing both front and back end is very marketable, and there's even stacks which require minimal retooling (read: node.js). Alternatively, there's things like ML/AI, vision, control, embedded systems, crypto, and quite a few other sub disciplines which you might find more interesting, at the cost of a steeper learning curve. MIT has quite a large number of courses online (even in video form) with OCW/edx, and there are certainly quite a few other resources available for learning if you have the time/interest/energy. Picking up new languages is probably a good place to start, and it becomes very easy once you've written a few thousand lines in a couple different languages since there's so much conceptual overlap.

In terms of experience/resume items in order to get hired in a different specialization, I think that small toy/fun projects that display knowledge in a given subject matter are very good in terms of marketing yourself. Of course, this route takes a fair amount of time, but can be very rewarding and interesting if you pick projects that align with what you find cool. What you choose to do doesn't even have to be novel/groundbreaking to be very rewarding. It's also imo easier to learn things if it's in the context of needing solutions to practical problems. If you do go this route, I highly recommend making a small website that showcases what you have done. I did this, and have heard first hand from several managers that it was a primary factor in me getting an offer. I've even bombed interviews but still gotten an offer because of my website.

On the bright side, I do think that front end is a very useful skill in general - I use my web dev skills to display my other work and occasionally to pay the bills. If you do decide to pick up a different specialty, your time thus far will not have been wasted.

Good luck!!

kctess5··on Show HN: Academic Bio – A simple static site generator for academic webpages
Which would be much easier if only we had a static page generator generator generator!
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