skysight-inc/HackerNews huggingface dataset:
I'm an analyst for a quantitative hedge fund. Please, please everyone promise me to never base your investment decisions on this discredited form of mean-variance optimization.

This method of stock selecting was invented by Harry Markowitz in 1952. In the intervening sixty (!) years we have accumulated overwhelming evidence that plain vanilla mean variance optimization doesn't work. Among its many flaws:

1. It makes unrealistic assumptions about the distribution of returns (i.e. that they are multivariate normal, when it is well known that returns exhibit heavy tails, time-varying volatility, fluctuating correlations etc etc).

2. It relies on you having good estimates of the expected annual return of individual stocks. How do you propose to get these? Don't say you'll use historical measurements, unless you really believe that last year's return is a good predictor of this year's return (it's not, except perhaps in some sectors, and even then it's difficult to measure and you'd be subject to crash risk).

3. The optimization procedure is error-maximizing. That is, even if returns were multivariate normal and you had a reliable way to measure the expected return on stocks, you'd still have errors in your covariance matrix, and these errors are amplified by the optimization procedure. You can see this in the article, then the "optimum" portfolio recommends putting 75% of your portfolio in MSFT and shorting AMZN and AAPL. Does anyone really believe that's sensible? Does anyone believe that such a portfolio is diversified?

The problem is that your model of stock returns is subject to massive overfitting. Let's say you have data for the last 10 years (i.e. about 2500 days). If there are N stocks in your portfolio, you need N(N+1)/2 pieces of information to specify the covariance matrix, which puts an upper limit of 70 stocks in your universe (since 70 * 71 / 2 ~ 2500). A good rule of thumb is that you should have 10 observations per free parameter, which cuts that number down to 22 stocks (22 * 23 / 2 ~ 500). I think that most portfolios consisting of 22 single-name stocks aren't sufficiently diversified (and you'll still be subject to the first two problems above).

In 2012, no one should be using mean-variance optimization to select stocks. At the very least, shrink the covariance matrix toward some sensible prior (e.g. constant correlations, sector correlations, or a factor model) and backtest your strategy over the past 10-20 years and look at the annual volatility, size and length of drawdowns, skewness and information ratio.
>There is little to gain (and much to lose) by making it sound like bob was unattractive to the company, even if he was.

You appear to be stating this as a fact.

Also when the headline talked about "getting fired", most would probably differentiate that from "employee leaving", which usually implies by their own volition.
Indeed. If the author's claim is true, it's a configuration-specific bug. Proof: starting with my 10.7.4 template VM (a fresh install from the App Store image), I signed into both iCloud (with the default list of enabled features, including various synchronizations and Find My Mac) and the App Store, confirmed that "Allow user to reset password using Apple ID" was disabled[1], then used the App Store installer to upgrade to Mountain Lion. After the upgrade, the option was still disabled[2].

I did notice an unrelated bug, though: as can be seen in the screenshots, the upgrade appears to have enabled Guest User login.

[1] http://jasomill.at/Lion.png

[2] http://jasomill.at/MountainLion.png
You're confusing copyrights and patents. I agree that nobody should be able to own an idea, at least in software, but suggesting that nobody can own an implementation is naive anarchism.
This is word for word what I was thinking. Well played Randall from 58 minutes ago.
This is a great, detailed description about what it's like to do image processing from a space probe on Mars

http://cdn.oreilly.com/radar/2012/08/Beautiful_Data_Chapter3...

It's from O'Reilly's "Beautiful Data", made available free in honor of the current mars mission.

The short answer (covered in that document) is actually that the sensors have to be hardened for space use and are not consumer grade. They are incredibly expensive to produce.
No but I'd be happy to set that up
> Maybe it'd be clearer if I used the word placebo.

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

Potassium alum is an astringent/styptic and antiseptic. For this reason, it can be used as a natural deodorant by inhibiting the growth of the bacteria responsible for body odor.

> http://www.thecrystal.com/crystal_insights.cfm

How Does Crystal Body Deodorant Work? Odor is caused by bacteria that form on the body. Natural mineral salts form a barrier on the skin that creates a very unfriendly environment for these bacteria.

> You drastically underestimate...

All I have to say is try it for yourself.

Unless you think you're an expert on under-arm bacteria and odor... Which is odd concidering you work for Microsoft.
How Alan Turing Outsmarted Britain's Home Guard--and For Their Own Good
Isn't it absurd that someone would consider ignoring all of those points about technical details and user experience of free software because of license issues with other "free" software?

As a member of the illumos community, I long ago turned the question around: given ZFS, DTrace, Zones, and the rest, all available in a free (as in speech) operating system, why would I use a different system that prohibits incorporating all this valuable free software?
> Is it silent on Mars?

Good question! No, it is not. See http://sprg.ssl.berkeley.edu/marsmic/sound.html for an experiment, carried on the Mars Polar Lander, which would have attempted to record the sounds of Mars. Sadly the instrument was lost along with MPL.

> Just curious if Martian weather tends to be windy or calm

Another good question. Mars is quite windy. I don't have a reference handy, but Spirit and Opportunity recorded numerous dust devils on the Martian surface. IIRC, they sometimes saw more than one a day!
They need to hire a professional web designer. The web page looks like something that was resurrected from geocities.
(At least) #4 and #5 seem reasonable.
Pay TV should be “afraid, very afraid” of Google Fiber, SNL Kagan says
Embedded Image Data Processing on Mars (from "Beautiful Data") [pdf]
With a concentrated customer base and excellent logistics, they may be able to do much better than 3 deliveries per hour.
Newer versions of Steam don't require a security question for resetting your password; they instead send a confirmation code to your email address.
Heh, not your fault, I got that part. Should have looked at the username more closely before responding. :P
I clicked the link in his blog post, which took me here: https://alpha.app.net/. You're right though, 3 paragraphs into the blog there is a link to join.app.net.
Another problem is that the HN crowd has been getting inundated with a ton of 'Show HN: AppName v0.001' posts for a while now. There are some obvious benefits to doing this, like getting early feedback from tech-oriented people before chasing the general public's attention, but I wouldn't be surprised if the HN crowd is getting a little weary of wading through the onslaught of such posts.

Note: I actually think Grid's v1 was pretty well put together (based on the demo video). I am mostly referring to the half-backed Bootstrap sites with nothing more than a sign up form.
I really think the root problem is their allowance of 3rd-party sellers to create product listings. There needs to be a "master listing" for a specific product, to avoid the current problem of multiple duplicate listings -- which, like you said, may not actually be product X at all, but is product Y instead. It makes Amazon look like eBay.

Don't even get me started the self-published ebook spam -- is Amazon just ignoring it?
Use It Better Helps Developers Understand How Their Games Are Being Played
Is there a formal term for this? Perhaps "the Walmart Effect"? =P
I first listened to this from the TechCrunch article on an iPad through the speakers and it didn't seem all that bad. I got to my desktop and was going to give you a hard time, but listened to it again with my headphones on. Yeah, the sound could definitely benefit from being turned down a few notches toward the middle of the video. Surprisingly it seems to calm down towards the end.
Why is app.net better than identi.ca? Honest question, I am curious
So, someone made a twitter clone?
Zynga Open Sourced "hiccup"
I knew my bait would bring someone smarter than me out of the woodwork! Thanks, very informative. Can I ask what's your background that led you to this?
I don't get the impression anyone here is actually that concerned on an ethical level about the potential for criminal abuse. But it's likely to become an issue if the product is widely used, and it's worthwhile to ask if the developers have a strategy for dealing with the kinds of dilemmas that could arise. It's a business question, not a moral one.
Normal "color" cameras are also false-color filtered. They just have the filters applied per-pixel instead of over the whole sensor at once. http://en.wikipedia.org/wiki/Bayer_filter
You only have to "Enable access for assistive devices" for the in-game interface, because it requires directly controlling the hardware. In Windows this is done by dll injection, of which even a similar process isn't possible in any *NIX operating systems.
fyi - SF min. wage is $10.24/hr - although I just got an invite to the app and if it's true to their word I'll use it all the time - I was using safeway delivery before as I don't have a car currently and it's a real pita to do groceries w/out - even zipcar will cost around that much plus your time
Mine haven't been back for some time; I better let them know they're late!
One of Linus's main points is that this is a layer problem.

Who cares if things get normalized in your Finder dialogs or other UX elements? But if something is being programmatically done to the filesystem itself (ie, by git via a write) it should do what is advertised -- write some bits. It seems wrong that the filesystem itself should be concerned with normalizing filenames or flipping bits of any kind.
medusa666, you appear to be hellbanned. All of your comments for the past 3 weeks are [dead]. I don't see anything obviously spammy in your history, although a karma of -2 is curious.
This was not for lack of effort. You can only get OAuth creds from Google accounts on Android, and we use OpenID. If you have information otherwise, please tell us: http://stackoverflow.com/questions/11347801/use-google-openi...
Yup. I just downloaded it and signed in with my Trello account name. I was actually thinking to myself that it seemed like a really pleasant sign-in experience (they provided a nice list explaining permissions). I actually came away happy. Imagine that.
Because it makes Dalton Caldwell money. At least, that's the reason Caldwell would give you.

If Caldwell actually cared about making "a real-time social service where users and developers come first, not advertisers" he'd build something on status.net, or at least something open source.
It's not a layer problem. The fundamental problem is Linux is geared towards servers and HFS+ is geared towards consumers. On a server, it makes sense that whatever filename your program tries to write out is preserved perfectly. On a consumer-facing OS that's a terrible idea. Having mis-normalized filenames can cause all sorts of confusion. The most obvious is having two filenames that are grapheme-for-grapheme identical, but differ in the normalization of their characters. Less obvious is how to deal with situations where the user types a filename to open and their typed normalization differs from the actual normalization of the file on disk? Unless the filesystem itself performs the renormalization, there's no sane way to deal with this situation besides iterating over the directory and renormalizing each filename in the hopes of finding a match.
HeyWire lets you get a U.S number for SMS for free.
Domain name availability.
Compare the global feeds:

https://alpha.app.net/global/

https://identi.ca/
It's in English, first off. :-)
Except in the case of senior staff, I think broadcasting someone's departure to all 120 employees is a bad approach in general. But if you're going to make an announcement whenever a low level employee is fired, best to couch it in the same sort of language.
> the most interesting things you can see are the dust
> devils and maybe/hopefully, ice formations

For the geologists who designed the scientific instruments on Curiosity, the most interesting things they can see are rocks. Lots of rocks, from different periods in the geologic history of Mars.

This is why Gale Crater was picked as the rover's landing site; there are several nearby features, including Aeolis Mons, that will provide the rover with an opportunity to date and investigate rock layers from different eras.
Anyone who knows Bob well enough to care, knows what happened. Anyone else will appreciate the positive tone.
I can accept that. I don't have anything that I'm willing to share. To be sure, I'm not suggesting that any of the companies (Apple, Google, Etc.) were willing participants.

Likewise, if you're looking for a discussion of this exact implementation of exploiting the trust relationships created by users of cloud services, you'll not find it.

That said, exploiting trust relationships that users naturally create in the cloud, is common. This is just one specific attack, designed to get page views and raise awareness.

It worked flawlessly. Life is but a dream.
And this is why I had my first screening session for CBT today. Thank you for putting into words precisely what I was thinking.
The problem is that the filenames are interpreted by computers, not by people. Your comment that filenames are "human-readable strings" is subtly changing the problem statement. You're conflating bits (interpreted by computers) with display (interpreted by humans).

They really are two fundamentally different things.

I've been working though similar i18n issues in the IETF. Various protocols started off as ASCII, and now need to support more. There have been 5+ years of heated discussion around the subject.

The consensus appears to be reaching the view that issues related to people are solely managed by the "human IO" portions of the computer. i.e. the display turns bits into glyphs, and the input turns keystrokes into normalized buckets of bits. Once the bits reach the rest of the system, everything else treats them as buckets of bits.

This approach means that the non-IO parts of the system are simple. Things like name comparisons are done via "memcmp". No i18n issues apply.

I'll go a little more extreme here, and say that IMHO this is the only approach which makes sense. Anything else is madness. Anything else means that your file system handles i18n.
Is there a single piece of information in here? It reads like another pitch, and I frankly don't think HN has been lacking in the "app.net" coverage department.

I think the founders should be more actively looking for funding on other channels, if they want to fill up that bar. HN seems like a saturated market.
how is identi.ca funded? I'm curious?

(I'm also a backer of app.net)
Ask PG: May I please have my IP unblocked?
Last night while writing a tool for Hacker News, my test code crawled through several pages of HN in rapid succession, resulting in an IP ban. I've since changed the test code to wait a while between requests to prevent server strain, but I would like to be able to return to HN on my own machine. I sent you an email with my IP address. Thanks in advance.
Try subscribing to a high volume mailing list like bugtraq or linux-kernel. For a search to yield any meaningful results you have to add -label:bugtraq -label:linux-kernel. for. every. single. search. Still, for the other 99.9999% of users who don't subscribe to mailing lists I'm sure it's great.
>My Amazon experience for clothing and shoes is roughly the same as for all other Amazon products; I visit a physical location to actually peruse/test the product (in this case, try it on) and then order it cheaply online.

Because so many of us (including myself) now behave in this manner, I'm fairly convinced that most brick and mortar stores will have to assume an "annual dues" model a la Costco to survive. (and offer some form of competitive advantage over Amazon, of course -- ex: focusing on item discovery rather than cookie cutter merchandise, etc.)
> most of a DSLR's weight is lens and battery(s), both of which are not issues in this case, since the lens would be the same

Only true if you assume the same sensor area for the 2MP sensor and the 16MP sensor, which is a poor assumption. If they did use sensors with the same area you would pay dearly with high noise and low sensitivity just to cram more pixels in there. I think most photographers figured out awhile ago that the "Megapixel War" is only meaningful as a way to pitch perceived quality to uninformed consumers.
Liberal Arts Colleges: A Tale of Three Campuses
My comment was going off your entire premise that using black was a nono because that is what you wrote.

We could even see it in your website design because you chose to use a grey font color over black (because I'm guessing you are on a mac and the font rendering works better). However if you look at it on windows it becomes harder to read because it is grey (http://i.imgur.com/CfTYi.png windows screenshot with black and grey)

I said that black can be used to focus in apps and websites and in digital mediums because it isn't realism that we are going for and black actually works really well for this purpose. The idea of using saturated colors is fine but not using black for the sake of it is silly.

Now using black in large quantities is another thing.
How to get Internet access in Rome – and how not to
"protect my privacy" is a really poor way to position this argument, if only for the many times we need to take companies to task for actually violating people's privacy. This is showing something on screen that you'd rather only have shown in a different tab.

The only reason you don't have the same reaction to the location bar in your browser showing browser history is that you're used to it.

If you don't want email results to show up on your search page, just don't turn it on.
Jaiku didn't have advertisers yet it failed.

I really root for app.net to succeed, also somebody please come up with a better Facebook, too much identity info managed by these two companies to feel a little unease, specially after their privacy fiascos.
identi.ca's global feed is a little messier, but not much (it also has more functionality, and although it's a matter of taste, I like the design). They seem to be about equally active, although identi.ca has users posting in multiple languages and they seem to not have bothered to split posts by language. Neither site has ads.

What am I supposed to be looking at?
In Minneapolis, we've had grocery delivery for quite a while now through Coborn's Delivers (http://www.cobornsdelivers.com/). It used to be Simon Delivers (http://en.wikipedia.org/wiki/SimonDelivers), a startup that went under and then was taken over by an existing local grocery chain.

We pay $5 for next-day delivery or $10 for same-day (for orders of at least $50, otherwise add another $5 to delivery).

It's a huge time saver, we have groceries delivered every Sunday and they have good selection and produce. The prices are a little more expensive, but it's totally worth it for us.

The startup I'm working at also uses it periodically to have soda and snacks delivered. Much easier and more reliable than having to send someone out every few weeks.
1) From my observations, platforms that did this weren't too successful (e.g. Stardock before turning into Impulse). We were also in a time where the Windows world didn't have a need for it and it's hard to deny that things have changed so much lately that people are expecting more centralised stores of applications.
ازياء شتاء 2013
YouTube has become a Kafkaesque nightmare, at least for regular users. They recently opened up monetization to everyone, but if you actually try to use it, half your videos will go "under review" and you will be asked to provide proof that you own all the content. They won't tell you specifically what you have to provide, and nobody I know has managed to figure it out or get a video out of this state. Of course, there is no way to contact anyone or get any more information.

Apparently, "full partners" can actually get real customer service and avoid these problems, but you need to get on the order of 1000 views/day before they offer you that, which most people never achieve.

I will absolutely never do business with that company.
The power of correctly aligned incentives are Huge.

http://pmarca-archive.posterous.com/the-psychology-of-entrep...
If you use Mark Otto's GitHub buttons your site is broken
I'd love to see movies on Steam, provided they are available worldwide. Amazon and Netflix cater nicely to Americans but the rest of the world has no good alternative.
Why Insync is better for power and business users?
I can't speak for the other poster, but for me, its mostly a sorting problem.

I do think Amazon has improved on this a lot. In the past I would find multiple listings, for the same product, from different merchants, under different names.

As an example, if I am looking for a specific Diesel jean I have waist, length, wash, and cut. The wash might be either described correctly, "0073N", or incorrectly "Dark blue." Looking at it now, this is much improved over where it was just a year ago.

On the other side of things, Amazon has a problem with fake products getting in their inventory by third party sellers being labelled as genuine -- another issue that has been getting better (The iPhone Charger listed as by Apple but priced like an iPhone app, was there for years.)
What kind of discussion can one have if one is not entitled to ones own opinion?
Brazil is voting on the world's first federal bill of Internet rights
It'll be interesting to see Amazon square off against a startup. They've been doing battle with B&M stores, Google and Apple. It'll be interesting to see how they deal with a company several orders of magnitude smaller than them. With the amplifying effect of YC behind them, it'll be interesting to watch.
The Origins of the Awesomeness of Spotify
Valve opens Steam store to non-gaming software
To be honest, I used Twitter initially because it was interesting to read and be in dialogue with the larger tech community in a way that I might not on, say, my Facebook (very technical discussions, etcetc). I could of course browse a Twitter list of twelve people, but the way I am willing to participate in Twitter changed the moment it became more than a tech ghetto. In fact, Twitter became essentially useless to me on that day. I could really think of worse things happening than another such niche social network emerging... Consolidation, especially of data, is incredibly overrated.
An Emacs web server existed over 10 years ago:

http://synthcode.com/emacs/phase-0.2.1.tar.bz2

It has no doubt bit-rotted, but had some really
nice features, like being able to automatically
display any file as HTML with the exact same
syntax highlighting that Emacs itself uses.
Anecdotaly, I had two experiences where my card got flagged by NewEgg, they didn't bother telling me until the next day. I cancelled the order, over nighted it from Amazon for almost exactly the same price.

I cringe every time I have to order something outside of Amazon, dreading a MasterCard secure card, frozen order, mis-packaged products, and any number of other issues that affect my physical goods purchases outside of their system.