Simplex

In geometry, a simplex (plural: simplexes or simplices) is a generalization of the notion of a triangle or tetrahedron to arbitrary dimensions. Specifically, a k-simplex is a k-dimensional polytope which is the convex hull of its k + 1 vertices. More formally, suppose the k + 1 points are affinely independent, which means are linearly independent. Then, the simplex determined by them is the set of points

For example, a 2-simplex is a triangle, a 3-simplex is a tetrahedron, and a 4-simplex is a 5-cell. A single point may be considered a 0-simplex, and a line segment may be considered a 1-simplex. A simplex may be defined as the smallest convex set containing the given vertices.

A regular simplex is a simplex that is also a regular polytope. A regular n-simplex may be constructed from a regular (n − 1)-simplex by connecting a new vertex to all original vertices by the common edge length.

In topology and combinatorics, it is common to “glue together” simplices to form a simplicial complex. The associated combinatorial structure is called an abstract simplicial complex, in which context the word “simplex” simply means any finite set of vertices.

Simplex (French automobile manufacturer)

Simplex is an automobile manufacturer that existed briefly, in France, between 1919 and 1921.

The name Simplex was used during the early years of the twentieth century by a number of automobile manufacturers including one each in the Netherlands and England, and by (at least) two auto-makers in North America. The French Simplex company was not connected with these.

The car

Simplex took a stand at the Paris Motor Show in October 1919 and exhibited a light “voiturette” style car featuring a single cylinder horizontal motor of 735cc. The motor was balanced by an imaginatively configured longitudinal counter-weight which was intended to limit engine vibrations.

The wheelbase was a relatively modest 2,300 mm (90.6 in). Front brakes were included.

The car’s “Bull-nose” style radiator is reminiscent of the pre-war Morris Oxford.

Sources and notes

Lucien Juy

Lucien Charles Hippolyte Juy was a French industrialist who made derailleur gears. He is credited with making the first derailleur with a collapsible parallelogram. A hinged frame swung in and out from the frame and fed the chain to one of a number of sprockets attached to the hub. Juy's derailleurs, sold as Simplex derailleurs, were novel in having a jockey wheel to correct the tension of the chain as it moved across differently sized sprockets.

History

Lucien Juy owned a bicycle shop in Dijon, Côte d'Or, France. It was there that he made the first Simplex derailleur in 1928. The bicycle historian Hilary Stone said: "It used a single pulley to tension the chain and a pair of guide plates to push the chain to each one of two sprockets. The whole arm was spring-loaded in order to tension the chain – this was the first use of the sprung top pivot which was to become an essential part of the modern indexed derailleur as we know it today. The pulley and guide plates were moved sideways on a push-rod by means of a chain pulling through the centre of the push-rod. Lucien Juy managed to persuade the management of the Alcyon racing team to fit his Le Simplex gear to their machines for the 1928 Paris–Roubaix – unfortunately the riders revolted and refused to use the new unproven gears."

Dangerously in Love

Dangerously in Love is the debut studio album by American recording artist Beyoncé. It was released on June 20, 2003 by Columbia Records. During the recording of Destiny's Child's third studio album, Survivor (2001), the group announced that they would produce solo albums to be released. Recording sessions for the album took place from March 2002 to March 2003 at several studios, during the hiatus of her then-group Destiny's Child. As executive producer of the album, Beyoncé took a wider role in its production, co-writing a majority of the songs, choosing which ones to produce and sharing ideas on the mixing and mastering of tracks.

The tracks in the album are a mixture of uptempos and ballads, which are basically inspired by R&B and soul genres; it also features elements of hip hop and Arabic music. Although Beyoncé remained discreet about her interpretation of the songs, its underlying meanings were attributed by music writers as an allusion to her intimate relationship with boyfriend (later husband) and well-known music mogul Jay-Z. Dangerously in Love received positive reviews from music critics upon its release, with critics praising Knowles' "artistic leap". The album also received numerous accolades, earning Beyoncé five Grammy Awards.

Signs (album)

Signs is the second album from trip hop duo Badmarsh & Shri.

Reception

Allmusic criticized the album for being slow and poor quality for the first few tracks, but asserted that the duo has achieved a distinctive style and complimented Shri's multi-instrumental versatility.

Track listing

References

Signs (journal)

Signs: Journal of Women in Culture and Society is a peer-reviewed feminist academic journal. It was established in 1975 by Catharine R. Stimpson, and is published quarterly by the University of Chicago Press.

Scope

Signs publishes essays examining women's and men's lives around the globe from both historical and contemporary perspectives, as well as theoretical and critical articles addressing processes of racialization, sexualization, and gendering. In 2015, Signs launched the "Feminist Public Intellectuals Project," which seeks to engage feminist theorizing with pressing political and social problems via three open-access, online-first initiatives: "Short Takes," "Currents," and "Ask a Feminist." Given the fragmentation of feminist activism and the persistent negative freighting of the moniker “feminist,” the "Feminist Public Intellectuals Project" seeks to genuinely reimagine what role a journal can play in provoking activism.

History

From 1975-1980, the founding editor-in-chief of Signs was Catharine R. Stimpson (Barnard College). From 1980-1985, the editor-in-chief was Barbara C. Gelpi (Stanford University). From 1985-1990, the editor-in-chief was Jean Fox O'Barr (Duke University). She was succeeded from 1990-1995 by Ruth-Ellen Boetcher Joeres and Barbara Laslett (University of Minnesota). From 1995-2000, the editors-in-chief were Carolyn Allen and Judith A. Howard (University of Washington), they were replaced in 2000 by Sandra Harding and Kathryn Norberg (University of California, Los Angeles), they served until 2005 when they were replaced by Mary Hawkesworth (Rutgers University). Since 2015, Suzanna Danuta Walters (Northeastern University) has been editor-in-chief. The journal was called "prestigious" in a French review article of women's studies in America.