potash · HackerTrans

12 ปีที่แล้วdiscuss

Do you know of any research about the accuracy of forecasts as a function of sensor data input? I.e. what kind of an improvement will we see if some number of Android users install PressureNet?

potash

12 ปีที่แล้วdiscuss

Note that your code still forces python to read the entire file! If all you want is the last line of a file, use the UNIX tail:

  tail -n 1 $f

Tail seeks backwards so it will only read the one line. Of course, this won't give you a line count.

EDIT: I haven't tested it but you might be interested in this implementation of tail in python: http://stackoverflow.com/a/136368

potash

12 ปีที่แล้วdiscuss

> There may be a market opportunity for an economist to write a big Piketty-style book on climate change.

Yale economist Bill Nordhaus' Climate Casino is that book. And his research with integrated assessment models concluded:

> The consequences of [climate change] will be costly for human societies and grave for many unmanaged earth systems; the balance of risks indicates that immediate action should be taken to slow and eventually halt emissions of CO2 and other greenhouse gases.

And, by the way, this analysis doesn't even take into account tipping points!

potash

12 ปีที่แล้วdiscuss

Interesting. Thanks!

potash

12 ปีที่แล้วdiscuss

Offtopic: It's funny that an article about polyglottism has a grammatical error in the title and a misspelling in the first sentence.

potash

12 ปีที่แล้วdiscuss

Why not? Unless I'm missing something, constructive interference is still additive and power loss is still inverse square.

Of course batteries also have power transmission inefficiencies. My intuition though is that wireless power has potential to be more efficient than batteries for two reasons:

- While building out the infrastructue is an enormous proposition, I'd guess that it is much more sustainable to maintain than batteries.

- When the application is propulsion, not having to carry a fuel source (e.g. battery) is huge. On a Tesla Model S, the battery is more than a third of the weight (450kg of 1235kg, according to Wikipedia).

potash

12 ปีที่แล้วdiscuss

How hard would it be to solve this deterministically?

Can someone comment on the game's physics? I am assuming:

  - constant horizontal velocity
  - gravity
  - flapping implemented via impulse
  - collisions are handled with bounding boxes

Maybe someone who knows something about optimal control (ODE) say whether this is analytically solvable? Of course there's still the practical stuff (numerical integration, I/O lag) to deal with but I'm optimistic.

potash

12 ปีที่แล้วdiscuss

Interesting, I'd never thought about this before. In case you (or anyone else) are still wondering...

If an A3 sheet is X units by Y units (with X the long side) and A4 is 2Y units by X units then their ratios are X/Y and 2Y/X, respectively. If these are equal we have

2Y/X = X/Y

cross multiplying gives

2Y^2 = X^2

rearranging and taking a square root (X and Y are positive) gives

X/Y = sqrt(2).

potash

13 ปีที่แล้วdiscuss

P.S. I agree this is pointless. The best solution in my opinion is simply ssh and [h]top or glances.

potash

13 ปีที่แล้วdiscuss

Of course! ssh -X. Obviously requires conky (and a minimal X server) on the server.

potash

13 ปีที่แล้วdiscuss

Cool. Not a lawyer but I think that if you are not copying the main content (just the metadata) AND putting the source in your bibliography you should be okay.

Also one simple way to try to raise money for the site is to use affiliate links to Amazon for any [e]books in the bibliography.

potash

13 ปีที่แล้วdiscuss

Great site design. A couple ideas off the top of my head:

- Let hikes to include GPS route(s) to display on the map.

- Link to the USGS topo map that covers a given hike: http://store.usgs.gov/b2c_usgs/usgs/maplocator/(xcm=r3standa...

- Add a bibliography to each hike.

- Scrape some websites to create "stubs" for new hikes and encourage users to develop these.

- Speaking of stubs, if you are going to have collaboratively edited content why not just build on MediaWiki or similar?

- Use OpenStreetMaps instead of GMaps and encourage users to add trails to OSM.

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