W2

W2 or w2 can refer to:

Parameterized complexity

In computer science, parameterized complexity is a branch of computational complexity theory that focuses on classifying computational problems according to their inherent difficulty with respect to multiple parameters of the input or output. The complexity of a problem is then measured as a function in those parameters. This allows the classification of NP-hard problems on a finer scale than in the classical setting, where the complexity of a problem is only measured by the number of bits in the input. The first systematic work on parameterized complexity was done by Downey & Fellows (1999).

Under the assumption that P ≠ NP, there exist many natural problems that require superpolynomial running time when complexity is measured in terms of the input size only, but that are computable in a time that is polynomial in the input size and exponential or worse in a parameter . Hence, if is fixed at a small value and the growth of the function over is relatively small then such problems can still be considered "tractable" despite their traditional classification as "intractable".

Arado W 2

The Arado W 2 was a two-seat twin-engine seaplane trainer developed for the DVS in 1928. It was a cantilever monoplane with a fabric-covered steel tube fuselage that accommodated the pilot and instructor in tandem open cockpits. The undercarriage consisted of two pontoons carried on steel struts.

Specifications

General characteristics

Performance

References