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apu

4,164 karma · joined October 23, 2007

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apu··on How to Get a Job With a Philosophy Degree
Or you could become Paul Graham =)
apu··on Amazon ElastiCache - Now With a Dash of Redis
Wow, this is yet another major step forward for redis adoption! Congrats to antirez and the whole redis team!
apu··on Bigshot: The Camera for Education. DIY Digital Camera Construction
This is a really cool project from my former PhD lab. It's a camera kit that teaches kids how cameras work by letting them assemble one themselves. The website [1] includes a lot of educational material describing how and why each component works, along with interactive animations.

The camera itself is also interesting in that it contains a few different "computational imaging" lens-systems within: normal, wide-angle, and stereo, "all-in-one". See [2] for a description of what computational imaging means in general. I'm happy to try to answer any questions (this wasn't my project, but I did play around with one).

[1] http://www.bigshotcamera.com/experience

[2] http://www.cs.columbia.edu/CAVE/projects/what_is/

apu··on Bigshot DIY camera aims to teach kids tech basics
This is a really cool project from my former PhD lab. It's a camera kit that teaches kids how cameras work by letting them assemble one themselves. The website [1] includes a lot of educational material describing how and why each component works, along with interactive animations.

The camera itself is also interesting in that it contains a few different "computational imaging" lens-systems within: normal, wide-angle, and stereo, "all-in-one". See [2] for a description of what computational imaging means in general.

I'm happy to try to answer any questions (this wasn't my project, but I did play around with one).

[1] http://www.bigshotcamera.com/experience

[2] http://www.cs.columbia.edu/CAVE/projects/what_is/

apu··on How we're going to change Georgia Tech
Agreed, from someone who was there at roughly the same time.

(I was AE 2000-2005...I wonder if we overlapped?)

apu··on Yahoo Acquires Xobni
$60 million is an acqui-hire?
apu··on Cryptography is a science, not engineering
Wow this is so out of line.

I can't believe you'd write something this awful as a direct personal attack.

apu··on Choosing Hong Kong Is a Brilliant Move by Edward Snowden
Strong agree (for both rayiner and tptacek). It's amazing how much abuse has been heaped on them for simply putting things into perspective, for questioning stories, for thinking carefully about what's actually being stated and claimed by various parties.
apu··on Real-Time Garbage Collection Is Real
Adding the initial http links it automatically:

http://www.cs.virginia.edu/~cs415/reading/bacon-garbage.pdf

apu··on Startup advice
I think it's from this PG essay: http://www.paulgraham.com/start.html:

One of the best tricks I learned during our startup was a rule for deciding who to hire. Could you describe the person as an animal? It might be hard to translate that into another language, but I think everyone in the US knows what it means. It means someone who takes their work a little too seriously; someone who does what they do so well that they pass right through professional and cross over into obsessive.

apu··on Japan Starts to Recharge After Two Lost Economic Decades
I don't believe I took the quote out of context, as I wrote what Friedman said, almost verbatim without commentary.

"Out of context" means you omitted other text that changes the meaning of the text you did quote. See rayiner's comment about this (the very next paragraph...)

The monetary base is the stuff consumers touch

No, it is not. See the wikipedia link and Rayiner's comment, which explicitly refutes this (The monetary base must not be confused with the money supply which consists of currency circulating in the public)

It is hard to take your arguments on good-faith if you make such blatantly false statements.

apu··on A Hacker News For Ideas
Heh, have you seen the source of this site, the one you're posting on?

Also, if the new site can avoid comments like this, it might actually have a chance =)

apu··on Show HN: API for detecting people, cars, and everyday objects in images
The relevant table on the results page is Table 3, which is detection performance. Classification is actually an easier problem (see Table 1), in part because the types of scenes in which different classes appear are often quite different, making it easy to avoid some "easy" mistakes.
apu··on Show HN: API for detecting people, cars, and everyday objects in images
It's not quite what you want, but I worked on Leafsnap [1], which automatically identifies trees by their leaves, using computer vision techniques. We focused on leaves since they are present throughout much more of the year than flowers. Our free apps also include high-resolution, high-quality photos of all aspects of the species we cover -- leaves, flowers, fruits, bark, etc. So you can at least browse through and compare the flowers you're looking at with those in the app.

Our current coverage is of the trees of the northeast US (about 200 species), but we are working on expanding that.

[1] http://leafsnap.com

apu··on Show HN: API for detecting people, cars, and everyday objects in images
Looks like this is using training data from the PASCAL VOC object detection challenge [1], which is the standard benchmark for evaluating object detection performance in computer vision.

Object detection is an extremely tough problem (some would say it is the computer vision problem ;-)), and while we've made a lot of progress in the past decade, the best methods are still terrible [2] -- average detection precision between 30-50%. For reference, most consumer applications require an AP of 90+% to be considered usable.

So if this is a completely automated solution, it's not going to be able to do much better, unless the creators can make massive (I mean orders-of-magnitude) improvements on the state-of-the-art.

But that being said, there are some applications where lower performance is acceptable. And if you add some manual verification, you could conceivably make this much better (with an increase in latency, though). Another possibility is to specialize on a certain type of input image (e.g., if you're a company taking photos in your warehouse, where all your photos look very similar and/or you can control the lighting and environment).

Still, I'm excited to see companies attempting to take object detection out to the real world. All the best to these guys!

[1] http://pascallin.ecs.soton.ac.uk/challenges/VOC/

[2] http://pascallin.ecs.soton.ac.uk/challenges/VOC/voc2011/resu...

apu··on McAfee Interviewed in Secret Location
This is probably the only time this link is relevant here: http://www.youtube.com/watch?v=xGvNE9y5POI
apu··on The Quiet Ones
If you read his comics [1], you'll see that he's quite self-aware of his own failings and realizes that he is often a jerk himself (sometimes unknowingly). I also got the sense from just this article that he was quite aware of the fact that he was being the asshole.

[1] http://www.thepaincomics.com/

apu··on Hacker News App Comparison for Android
Also, iHackerNews has links to 'viewtext' on the article, which works on about 75% of articles that I've tried, and saves a lot of badnwidth/cpu/ram.

The viewtext service is also incredibly awesome for printing out articles on paper -- I've found it to be much better than even the custom "print" versions of many articles, and certainly better than readability, etc.

apu··on Hacking on Side Projects: The Pool Ball Tracker
Yes, predictions can greatly improve recognition performance. Not only can you focus the bulk of your computations on the expected region of interest, but you can also potentially reason about appearance (e.g., if you know the frame-rate/integration time of the camera and expected speed of the ball, you could get estimates about how much blur to expect). You could also better handle difficult cases, such as when balls strike each other (e.g., simple conservation of momentum estimates should greatly constraint possible hypotheses for ball positions).
apu··on Telling people to leave finance
What about TARP's big brother, TALF (at least $1 trillion)? We don't even know where most of the money has been spent.

http://en.wikipedia.org/wiki/TALF

"The way TALF loans were set up, 100 percent of any profit is retained by the borrower, but the Fed and the Treasury absorb any losses."

apu··on Telling people to leave finance
Tell that to the Bear Stearns equity holders, who were 99% wiped out, or the Lehman Bros. equity holders who were completely wiped out.

Goldman Sachs? Citibank? AIG (to pay back Goldman Sachs)?

apu··on Telling people to leave finance
For a slightly different perspective on Bridgewater: http://nymag.com/news/business/wallstreet/ray-dalio-2011-4/
apu··on Face detection for cats in JavaScript
This work is based on a fairly old research paper. Since then, there has been significant progress on detecting dogs and cats more reliably.

Two prominent groups that are working on it are Andrew Zisserman's group at Oxford: www.robots.ox.ac.uk/~vgg/publications/2012/parkhi12a/parkhi12a.pdf

And Peter Belhumeur's group at Columbia University, who'll be presenting a new paper on detecting and recognizing dog breeds at the European Conference on Computer Vision (ECCV) in 2 weeks. [Peter was my PhD advisor]

More generally, many people in computer vision are getting excited about "fine-grained visual categorization," which is about classifying things at roughly the "species" level. This is in contrast to a lot of the previous computer vision literature, which either focused on generic categories (e.g., people vs animal vs car vs rocket-propelled-grenade) or specific object/instance recognition (e.g., face recognition).

apu··on Bret Victor: Learnable Programming
Why do systems need millions of lines of code?

If you can build a complete operating system + major programs in 20,000 lines of code, what system should need a million?

http://www.vpri.org/pdf/tr2008004_steps08.pdf

(They're not quite down to 20,000 yet, but they're getting there)

apu··on Google Spanner's Most Surprising Revelation: NoSQL is Out and NewSQL is In
Muphry's law
apu··on Diaspora Will Now Be A Community Project
Forgive me if this was not your intention, but I feel like the way you phrased this (and the fact that it's currently the top comment on this story) is symptomatic of some of the negativity that's recently been rising on HN.

The first sentence is snarky and a put-down. The second sentence is a quasi-apology for the first line. The third sentence disparages the work done by people who, in all likelihood, worked very hard, had good intentions, suffered through horrible events, and were at least reasonably competent.

Also, there is no indication that you have any inside information about this, and you did not elaborate on why you were "deeply disappointed in their execution" -- do you have anything to suggest that anyone else would have executed better, given the circumstances? Isn't it better to give them the benefit of the doubt? Couldn't you express disappointment that the project isn't complete without putting down the people who worked on it?

apu··on Principle Component Analysis
FYI Eigenfaces was a ground-breaking theory when introduced...almost 25 years ago. It's no longer used in any serious way for practical face recognition applications.
apu··on Matasano Security acquired for £8.4m ($13m) - Congrats tptacek
Two discussions:

http://news.ycombinator.com/item?id=639647

http://news.ycombinator.com/item?id=1030560

The original post:

http://chargen.matasano.com/chargen/2009/7/22/if-youre-typin...

apu··on Smart Headlights Let Drivers See Through Rain and Snow
Project page with many videos, including entire talks given by one of the authors here: http://www.cs.cmu.edu/~ILIM/projects/IL/smartHeadlight/

The project is still in the academic research phase and I don't think they're quite as far as actually implementing it in a car in the wild, although they're moving ahead with it as fast as they can, so they might have actually done this recently. It won an award at the last International Conference on Computational Photography (ICCP) because it's just such a cool idea, and it seems like it might actually be feasible to some degree (even despite all the issues people have mentioned here and elsewhere). At ICCP, it was still in simulation and prototype-with-rain-machine-in-the-lab mode.

Btw I highly recommend watching the ICCP talk, available to watch from that webpage, or for download here: http://www.cs.cmu.edu/~ILIM/projects/IL/smartHeadlight/media...

apu··on Captchas Are Becoming Ridiculous
So back when I was a PhD student, we had an idea for a Captcha system that would be better than the current system and all alternatives by quite a margin, but we talked to some experts in the area, and they said that none of this matters because captchas are normally broken by feeding them to mturkers or people wanting to get into porn sites.

Is that no longer true? If so, I should look at reviving our old system.

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