Disk (mathematics)

In geometry, a disk (also spelled disc) is the region in a plane bounded by a circle. A disk is said to be closed or open according to whether it contains the circle that constitutes its boundary.

Formulas

In Cartesian coordinates, the open disk of center and radius R is given by the formula

while the closed disk of the same center and radius is given by

The area of a closed or open disk of radius R is πR² (see area of a disk).

Properties

The disk has circular symmetry.

The open disk and the closed disk are not topologically equivalent (that is, they are not homeomorphic), as they have different topological properties from each other. For instance, every closed disk is compact whereas every open disk is not compact. However from the viewpoint of algebraic topology they share many properties: both of them are contractible and so are homotopy equivalent to a single point. This implies that their fundamental groups are trivial, and all homology groups are trivial except the 0th one, which is isomorphic to Z. The Euler characteristic of a point (and therefore also that of a closed or open disk) is 1.

Staré

Staré is a village and municipality in Michalovce District in the Kosice Region of eastern Slovakia.

History

In historical records the village was first mentioned in 1221.

Geography

The village lies at an altitude of 107 metres and covers an area of 6.234 km². The municipality has a population of about 700 people. The name was taken from grof Staray.

See also

References

External links

Coordinates: 48°52′N 21°52′E / 48.867°N 21.867°E / 48.867; 21.867

Growth–share matrix

The growth–share matrix (aka the product portfolio, BCG-matrix, Boston matrix, Boston Consulting Group analysis, portfolio diagram) is a chart that was created by Bruce D. Henderson for the Boston Consulting Group in 1970 to help corporations to analyze their business units, that is, their product lines. This helps the company allocate resources and is used as an analytical tool in brand marketing, product management, strategic management, and portfolio analysis. Analysis of market performance by firms using its principles has recently called its usefulness into question.

Overview

To use the chart, analysts plot a scatter graph to rank the business units (or products) on the basis of their relative market shares and growth rates.

Star (Belly album)

Star is the debut album by the American band Belly. It was released in 1993 and was an unexpected success, going Gold in the USA. The single "Feed the Tree" became a #1 Modern Rock hit, and the album was nominated for two Grammy Awards. "Slow Dog" peaked at #17 on the Modern Rock chart in the summer of 1993, while "Gepetto" peaked at #8 in the late fall/winter of 1993.

The album and group received two Grammy nominations in 1994 for Best Alternative Album and Best New Artist. The music video for "Feed The Tree" was a smash buzz bin MTV hit, and was nominated for Best Alternative Video VMA and Best New Artist VMA in 1993. Follow up videos for "Slow Dog" and "Gepetto" didn't have the same cross-over success, but were popular on Alternative and Rock segments and outlets of MTV and VH1.

"Feed the Tree" also became a surprise pop hit peaking at #95 on the U.S Billboard Hot 100 singles chart in the late spring of 1993. Before breaking into the Hot 100 it was a chart topper on the Billboard Bubbling Under The Hot 100 singles for 6 weeks. While "Gepetto" did not match the success of "Feed The Tree" it charted on the Billboard Bubbling Under The Hot 100 Singles for 5 weeks in the late fall/winter of 1993 becoming a modest Pop hit and a signature song.