Index

An index is an indirect shortcut derived from and pointing into a greater volume of values, data, information or knowledge. Index may refer to:

Business

Publishing

Database index

A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time a database table is accessed. Indexes can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records.

An index is a copy of select columns of data from a table that can be searched very efficiently that also includes a low-level disk block address or direct link to the complete row of data it was copied from. Some databases extend the power of indexing by letting developers create indices on functions or expressions. For example, an index could be created on upper(last_name), which would only store the upper case versions of the last_name field in the index. Another option sometimes supported is the use of partial indices, where index entries are created only for those records that satisfy some conditional expression. A further aspect of flexibility is to permit indexing on user-defined functions, as well as expressions formed from an assortment of built-in functions.

Index (statistics)

In statistics and research design, an index is a composite statistic – a measure of changes in a representative group of individual data points, or in other words, a compound measure that aggregates multiple indicators. Indexes summarize and rank specific observations.

Much data in the field of social sciences is represented in various indices such as Gender Gap Index, Human Development Index or the Dow Jones Industrial Average.

Item in indexes are usually weighted equally, unless there are some reasons against it (for example, if two items reflect essentially the same aspect of a variable, they could have a weight of 0.5 each).

Constructing the items involves four steps. First, items should be selected based on their face validity, unidimensionality, the degree of specificity in which a dimension is to be measured, and their amount of variance. Items should be empirically related to one another, which leads to the second step of examining their multivariate relationships. Third, indexes scores are designed, which involves determining their score ranges and weights for the items. Finally, indexes should be validateds, which involves testing whether they can predict indicators related to the measured variable not used in their construction.

Tango

Tango is a partner dance that originated in the 1880s along the River Plate, the natural border between Argentina and Uruguay, and soon spread to the rest of the world.

Early tango was known as tango criollo (Creole tango). Today, there are many forms of tango extant. Popularly and among tango dancing circles, the authentic tango is considered to be the one closest to the form originally danced in Argentina and Uruguay.

On August 31, 2009, UNESCO approved a joint proposal by Argentina and Uruguay to include the tango in the UNESCO Intangible Cultural Heritage Lists.

History

Tango is a dance that has influences from European and African culture. Dances from the candombe ceremonies of former slave peoples helped shape the modern day Tango. The dance originated in lower-class districts of Buenos Aires and Montevideo. The music derived from the fusion of various forms of music from Europe. The word "tango" seems to have first been used in connection with the dance in the 1880s, possibly related to the Latin word "tangere" but more likely related to the African slave word "tango" (drum or dance place).

Tango (Julio Iglesias album)

Tango is a studio album released by Spanish singer Julio Iglesias on November 19, 1996. This album became his first number-one set on the Billboard Top Latin Albums and the recipient of a nomination for a Grammy Award for Best Latin Pop Album.

Julio went on to win a World Music Award for Tango in the summer of 1996 when he was up against Luis Miguel and son Enrique.

Track listing

The information from Billboard.

Chart performance

Sales and certifications

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See also

References

Commuter Cars Tango

The Tango is an ultra-narrow electric sports car initially designed and built by Commuter Cars, an American company based in Spokane, Washington, that sells this car worldwide for $108,000.

Production of the first version, at a rate of about 100 cars per year, was set to begin in late 2005. Actor George Clooney took delivery of the first Tango kit on August 9, 2005, which was a major milestone for the company. Clooney appeared in the press with the car, explaining and promoting it. Difficulties with their UK manufacturer forced CommuterCars to take over manufacturing themselves; for this reason the second vehicle did not ship until February 11, 2008, and was completely assembled in Spokane, Washington. The second car eventually found its way into the second-floor office of Google CEO Eric Schmidt as part of an April Fools' Day joke. By 2014 fewer than 20 cars had been built in the United States.

Overview

The Tango is thinner than some motorcycles and may be small enough to legally ride side-by-side with other small vehicles in traffic lanes in some jurisdictions. Capable of seating two passengers in a tandem seating arrangement, it only takes up one-quarter of a standard parking space and is able to park sideways in many cases. One prototype vehicle has been produced by the company and was shipped to Prodrive in the United Kingdom in January 2005, where the design was refined for production models.

Chill (casting)

A chill is an object used to promote solidification in a specific portion of a metal casting mold. Normally the metal in the mold cools at a certain rate relative to thickness of the casting. When the geometry of the molding cavity prevents directional solidification from occurring naturally, a chill can be strategically placed to help promote it. There are two types of chills: internal and external chills.

Types

Internal chills are pieces of metal that are placed inside the molding cavity. When the cavity is filled, part of the chill will melt and ultimately become part of the casting, thus the chill must be the same material as the casting. Note that internal chills will absorb both heat capacity and heat of fusion energy.

External chills are masses of material that have a high heat capacity and thermal conductivity. They are placed on the edge of the molding cavity, and effectively become part of the wall of the molding cavity. This type of chill can be used to increase the feeding distance of a riser or reduce the number of risers required.