30thElement's comments

30thElement | 11 years ago | on: Building the Largest Ship in the World

To expand a little, most container ships use bunker crude, which is borderline sludge. It even needs to be heated before being pumped out. But it's cheap and at the size, pressure, and speeds these engines run at they get most of the energy out of just about any fuel.

30thElement | 11 years ago | on: The Python I Would Like To See

Well of course you're getting a speed difference, look at how much extra work you're doing in the std::string code! The char[64]s are allocated once but you reallocate the std::strings every time. By pulling the declaration of s1, s2, and s3 to the top, I'm getting equivalent speed (g++ 4.4.7 with -g, 0.02s each time, clock() isn't any more accurate). And for essentially no runtime cost, you're getting memory safety and exception safety.

C++ is all about low-cost abstractions. Any speed difference between the C++ way and the C way should be very small, and the C++ way is safer. Use std::string (and std::vector and all the rest) unless you have a very good reason not too, and then you should probably just write your own custom implementation. Reverting to the C way is just asking for issues.

30thElement | 11 years ago | on: The ship that failed to change the world

Carrier attack groups have a refueling ship along with all the cruisers/attack ships. It probably makes sense, just going by the size differences the carrier would use more conventional fuel than all of its escorts combined, so having the carrier be nuclear powered doubles your range.

30thElement | 11 years ago | on: A detailed exposé on how the market is rigged from a data-centric approach

Is this comment real? You made this comment on a site that most people use to waste time, and where one of the top posts is an Assembly implementation of Flappy Bird.

Fun fact: HFT has an annual revenue ~1/50th[1][2] of Google's. What's worse: a few hundred people wasting their time moving prices of select stocks a few pennies, or several thousand wasting their time collecting scary amounts of data about you to try and get you to click an ad?

[1]http://en.wikipedia.org/wiki/High-frequency_trading#Market_s...

[2]http://en.wikipedia.org/wiki/Google

30thElement | 11 years ago | on: The Highest-Paid CEOs Are The Worst Performers, New Study Says

They are teams competing for trophies, though; the trophy is your money/market share.

But beyond that, artificial competition could be a good thing. The large companies have a lot of advantages over the smaller companies, like economies of scale and name recognition, but they also have an incentive to stifle innovation (either directly or indirectly through the Innovator's Dilemma) and erect barriers to entry. Allowing smaller companies to "steal" CEOs helps offset some of those advantages. Even if they aren't well suited to that role, the name recognition alone can be an advantage (just look at SolarCity).

But I keep going back and forth on this. Set the salary cap too high, and the small companies can't steal the CEO away. Too low and it doesn't properly reward them for the difficulties of managing 200k+ person companies. A proper middle ground, if it exists, would be hard to find and need constant adjustments.

30thElement | 11 years ago | on: The Highest-Paid CEOs Are The Worst Performers, New Study Says

That's not entirely true. The salary cap is because if teams paid the fair market value, the teams with a larger budget would be able to run away with it like the Yankees did in baseball (with over twice as many World Series titles as the next best). It keeps the league artificially competitive.

Keeping the business world artificially competitive is an interesting idea, and not as bad as I initially thought.

30thElement | 11 years ago | on: Ask HN: How exactly does Hacker News 'points' work?

No, there is no downvote for posts. Flagging is supposed to take the place of that, but only for posts that violate the rules. From the FAQ

  There are no down arrows on submissions. They only appear
  on comments after users reach a certain karma threshold.

30thElement | 12 years ago | on: How do hedge funds get away with it? Eight theories

You're right, the period was "hand picked", but that's because I was looking at a 5 year graph with the high and low marked, and just used those numbers. The movement before/after 2008 wasn't the 40 percentage points that would be needed for the hedge funds to do as poorly as the market, so I didn't bother.

But I just looked the exact numbers up. The S&P 500 opened January 2nd at 1467.97 and closed December 31st at 903.25. A 38.5% loss instead of the 60% I said, but that's still almost twice the loss of the hedge funds.

30thElement | 12 years ago | on: How do hedge funds get away with it? Eight theories

The second point is actually a point for hedge funds. The S&P 500 went from a high of 1576 near the end of 2007, to a low of 666 in the beginning of 2009 (October 07 to March 2009, specifically). Commodities had similar losses. If hedge funds only lost 20% when the general market lost almost 60%, they are a pretty good hedge against risk.

30thElement | 12 years ago | on: Passwords for JetBlue accounts cannot contain a Q or a Z

While the other answers about Sabre are probably right, I've heard that banks intentionally have stupid password policies to prevent password reuse. If one bank says "no special characters but most contain a number", another says "must contain a special character, but no numbers", and a 3rd says "must contain a number and special character", they can guarantee that if one of the 3 is hacked into it doesn't compromise people with accounts at all 3 (of course ignoring people using "password" with a 1 or ! on the end).

30thElement | 12 years ago | on: Knightmare: A DevOps Cautionary Tale

A kill switch wouldn't have saved them. What killed Knight wasn't the $400 million loss, it was the lack of confidence all other firms had in them afterwards. Brokers can't just shut down in the middle of the trading day.

They managed to raise the money to cover the loss, but afterwards they were getting round 10% of their normal order volume [1].

Somewhat ironically, the closest thing they had to a kill switch, backing out the code, actually made the situation worse as it made all 8 servers misbehave instead of just the first one[2].

The full SEC report in [2] is an interesting read, just skip the parts about "regulation 5c-15...".

[1] http://www.businessinsider.com/look-how-knight-capitals-trad...

[2] http://www.sec.gov/litigation/admin/2013/34-70694.pdf

30thElement | 12 years ago | on: TrueCrypt Security Assessment [pdf]

They should do it only in situations where it doesn't change the program behavior. I use memset frequently in C just to be safe, but if it's written to later on before it's ever read from, the compiler can optimize that away. I'm guessing their recommendation here is if you did something like

    char* plain_text = malloc(size);
    ///do stuff with plain_text
    memset(plain_text, 0, size);
    free(plain_text);
For most programs that last memset is unnecessary (and may even be unnecessary according to the standard, but it's probably implementation defined, not undefined behavior) and it makes sense for the compiler to optimize it away. But for crypto purposes you have to be afraid of someone being able to read plain_text later, so the memset is important

30thElement | 12 years ago | on: Boston Doctors Can Now Prescribe You a Bike

The NYC equivalent is losing money because everyone got a annual pass and not many tourists are using it. The tourists are the real money makers, as only 10 daily passes or 4 weekly passes will be the same cost as an annual pass[1].

If I was the program director though, I wouldn't be worried yet. We just got out of the coldest winter in recent years, and in a few months we can tell if no one is riding the bikes because the novelty wore off or because it was cold.

http://www.citibikenyc.com/pricing

30thElement | 12 years ago | on: A Fervent Defense of Front-running HFTs

You completely missed his point about the difference between non-public information and new analysis on public information. Anyone can go and count the number of cars in a WalMart parking lot. This is new analysis on public information, not non-public information.

30thElement | 12 years ago | on: After Big Bet, Hedge Fund Pulls the Levers of Power

Except you completely missed the point where Ackman isn't making any money off this.

> Mr. Ackman has said he will donate any profits he personally earns to charity, calling it “blood money.”

And that's ignoring the fact that we live in a capitalist society. You need money to get things done. If no one stood to make a profit from this the effort wouldn't be nearly as well run. This is the market working at its best (at least in principle), rewarding people who put in lots of effort to reveal information that benefits the public.

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