Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 Internet speed test! ×

Submission + - Reddit Emboldens Young Woman to Fight Trademark Troll, We Win (boingboing.net)

Faulkner39 writes: "Ali Spagnola, a Pittsburgh based musical artist, is an advocate of social media, free paintings, and alcohol accompanied partying. To unite the beer loving citizens of the internet, she composed 60 original songs and created a "Power Hour Drinking Game Album" based on the popular college pregame ritual. When a trademark troll was awarded rights to the term "Power Hour", he issued a Cease-and-Desist order on Ali to stop selling her game, had her albums taken down from Amazon and Rhapsody, and began bullying her on the internet and social media. Reddit was not amused, and quickly escalated her story to the front page. The online support encouraged Ali to stand up and fight for our right to binge responsibly. After a 3 year legal struggle costing Ali $30,000 of her own personal money in legal fees, Ali won, giving the internet the right to Power Hour freely. To celebrate the victory, Ali is now running a campaign to fund a Power Hour Freedom Victory Tour"

Comment Quantitative Analyst (Score 3, Interesting) 416

In the Financial industry, "Quants" or Quantitative Analysts use statistics and sophisticated heuristics to feed ideas and information to organizations that deal with trading in the various markets (stocks, options, futures, commodities, forex, etc.), such as hedge funds, statistical arbitrage operations, and private investors. It's a high paying, highly challenging position that deals with all kinds of mathematical functions and techniques, such as optimizing adaptive filters. It's one of the best places for a mathematician to earn a great salary, but your skill and experience needs to be very top level.

Comment Private Enterprise is the way (Score 1) 583

I am strongly in support of privatized/commercial space exploration, such as SpaceX and Virgin Galactic. For all the standard reasons of competitive innovation, and public accessibility, I believe this is one of the most promising endeavors that people can take on, despite the seemingly impossible barriers space imposes.

Comment Re:What does the hell does NP Hard mean? (Score 2) 195

Correction: I confused PSpace with P. The above definition is for P and NOT PSpace. Haven't spent much time thinking about complexities ABOVE NP hard. PSpace actually considers the "memory" you need to solve the problem. This is relevant when you talk about Turing machines, where you have to use "tape" that you "write on" while solving the problem. The thing that's been proved is that you only need a polynomial amount of memory (relative to 'n') to solve problems that need NP Hard time.

Comment Re:What does the hell does NP Hard mean? (Score 2, Informative) 195

To solve a problem that has 'n' parts in it:

PSpace hard means the problem is relatively simple, maybe check n things n times, which is only n*n things. For example, "For n cities, find the sum of all the distances between all the cities".

NP hard usually means you have to start at one part, then make a new decision each time you want to move on to the next part. The classic example is: "for n cities, start at a city and find the shortest possible distance to visit each city once". Since you have to make a new decision every time, you can solve this problem using permutations: you have n choices for the first city, then n-1 choices for the next city, then n-2 choices for the next city, and so on. To check ALL of the possible routes you can take and select the shortest, you need to check (n)*(n-1)*(n-2)* ... * (2) * (1) things. That's a factorial, and is denoted n!.

So for 12 cities:
12*12 = 144
12! = 479,001,600

For 20 cities:
20*20 = 400
20! = 2.432902008×10^18

The "search space" for problems that are NP Hard explodes to quickly to solve any reasonably sized problem. So basically, computers can solve problems that are PSpace hard, but they can't really solve any NP hard problems that are worth solving. E.g., to solve the NP Hard "traveling salesperson" problem I described above for all the cities in Italy, there's something like 12000 cities, which is (almost) impossible to solve with a computer. For fun:

12000*12000 = 144,000,000
12000! = 1.201858406×10^43741 (and that's just nuts)

The above is not the only way a problem can be NP Hard, but all these kinds of problems have "similar" classes of "time complexity". If you model this "time complexity" (that is, count the number of things you have to check) as a function, PSpace hard problems are polynomials at worst. NP Hard are worse than polynomials. The notation used here is called "Big Oh", and the above two problems are O(n^2) and O(n!), respectively.

Slashdot Top Deals

There are running jobs. Why don't you go chase them?