Way Out West (festival)

Way Out West is a three-day music festival held in Gothenburg, during August that plays host to a variety of popular music artists from the rock and hip-hop genres. The main festival is complemented with the club concept Stay Out West which features after-hours gigs at various venues around the city; the first festival was held in August 2007 in Slottsskogen on Friday and Saturday and at club venues on Thursday and Saturday nights. In 2012 the festival became a full-fledged three-day festival with live music in Slottsskogen on Thursday. In addition to music, the festival has grown to incorporate other cultural activities such as art exhibitions in Slottsskogen and film showings at cinemas around the city; the festival has had a strong focus on being environmentally friendly and was the first festival in Sweden to become KRAV-certified. Citing environmental reasons, the festival announced on the evening before the first day of the 2012 festival that all food served to artists and visitors during the festival would be vegetarian.

This decision led to a furor of reactions, both negative. The debate culminated with the Gothenburg tabloid GT giving away free sausages and meatballs outside the festival entrance – a move that resulted in a Twitter dispute between the festival's press chief Joel Borg, co-founder of the festival, GT editors, highlighted by the Swedish media; the festival has won both national and international awards including: Gyllene Hjulet's 2012 Rights Holder for the Way Out West brand, Résumé's Monthly Outdoor Marketing Campaign, as well as the Most Innovative Festival at the MTV O Music Awards. The main festival takes place in the 137 hectare Slottsskogen park in central Gothenburg; when the festival area closes for the night there are more performances at various venues in and around central Gothenburg for example Gothenburg Studios. The first Way Out West was held on the 9, 10, 11 August 2007; the second Way Out West festival was held on 7, 8 and 9 August 2008. The third edition of Way Out West was held on 13, 14 and 15 August 2009.

The fourth edition of Way Out West was held on 12, 13 and 14 August 2010. The fifth edition of Way Out West with over 30 000 visitors was held on 11, 12 and 13 August 2011. Source: The sixth edition of Way Out West was held on 9, 10 and 11 August 2012. Source: The seventh edition of Way Out West was held on 8, 9 and 10 August 2013. Source: Azealia Banks, Neil Young & Crazy Horse, Solange were booked but cancelled their shows. Official website Photos from Way Out West 2007 Review and photos from Way Out West 2008 at Webcuts

Log wind profile

The log wind profile is a semi-empirical relationship used to describe the vertical distribution of horizontal mean wind speeds within the lowest portion of the planetary boundary layer. The relationship is well described in the literature; the logarithmic profile of wind speeds is limited to the lowest 100 m of the atmosphere. The rest of the atmosphere is composed of the remaining part of the planetary boundary layer and the troposphere or free atmosphere. In the free atmosphere, geostrophic wind relationships should be used; the equation to estimate the mean wind speed at height z above the ground is: u z = u ∗ κ where u ∗ is the friction velocity, κ is the Von Kármán constant, d is the zero plane displacement, z 0 is the surface roughness, ψ is a stability term where L is the Obukhov length from Monin-Obukhov similarity theory. Under neutral stability conditions, z / L = 0 and ψ drops out and the equation is simplified to, u z = u ∗ κ. Zero-plane displacement is the height in meters above the ground at which zero wind speed is achieved as a result of flow obstacles such as trees or buildings.

It can be approximated as 2/3 to 3/4 of the average height of the obstacles. For example, if estimating winds over a forest canopy of height 30 m, the zero-plane displacement could be estimated as d = 20 m. Roughness length is a corrective measure to account for the effect of the roughness of a surface on wind flow; that is, the value of the roughness length depends on the terrain. The exact value is subjective and references indicate a range of values, making it difficult to give definitive values. In most cases, references present a tabular format with the value of z 0 given for certain terrain descriptions. For example, for flat terrain the roughness length may be in the range 0.001 to 0.005 m. For open terrain the typical range is 0.01-0.05 m. For cropland, brush/forest the ranges are 0.1-0.25 m and 0.5-1.0 m respectively. When estimating wind loads on structures the terrains may be described as suburban or dense urban, for which the ranges are 0.1-0.5 m and 1-5 m respectively. In order to estimate the mean wind speed at one height based on that at another, the formula would be rearranged, u = u ln ⁡ ln ⁡, where u is the mean wind speed at height z 1.

The log wind profile is considered to be a more reliable estimator of mean wind speed than the wind profile power law in the lowest 10–20 m of the planetary boundary layer. Between 20 m and 100 m both methods can produce reasonable predictions of mean wind speed in neutral atmospheric conditions. From 100 m to near the top of the atmospheric boundary layer the power law produces more accurate predictions of mean wind speed; the neutral atmospheric stability assumption discussed above is reasonable when the hourly mean wind speed at a height of 10 m exceeds 10 m/s where turbulent mixing overpowers atmospheric instability. Log wind profiles are used in many atmospheric pollution dispersion models. Wind profile power law List of atmospheric dispersion models

Dinitz conjecture

In combinatorics, the Dinitz theorem is a statement about the extension of arrays to partial Latin squares, proposed in 1979 by Jeff Dinitz, proved in 1994 by Fred Galvin. The Dinitz theorem is that given an n × n square array, a set of m symbols with m ≥ n, for each cell of the array an n-element set drawn from the pool of m symbols, it is possible to choose a way of labeling each cell with one of those elements in such a way that no row or column repeats a symbol, it can be formulated as a result in graph theory, that the list chromatic index of the complete bipartite graph K n, n equals n. That is, if each edge of the complete bipartite graph is assigned a set of n colors, it is possible to choose one of the assigned colors for each edge such that no two edges incident to the same vertex have the same color. Galvin's proof generalizes to the statement that, for every bipartite multigraph, the list chromatic index equals its chromatic index; the more general edge list coloring conjecture states that the same holds not only for bipartite graphs, but for any loopless multigraph.

An more general conjecture states that the list chromatic number of claw-free graphs always equals their chromatic number. The Dinitz theorem is related to Rota's basis conjecture. Weisstein, Eric W. "Dinitz Problem". MathWorld. Retrieved 2008-08-17