In mathematics, particularly in abstract algebra and homological algebra, the concept of projective module over a ring R is a more flexible generalisation of the idea of a free module. Various equivalent characterizations of these modules are available. Projective modules were first introduced in 1956 in the influential book Homological Algebra by Henri Cartan and Samuel Eilenberg.
Jock D. Mackinlay is an American information visualization expert and Director of Visual Analysis at Tableau Software. With Stuart K. Card, George G. Robertson and others he invented a number of Information Visualization techniques.
Joseph Burtt Davy (7 March 1870 Findern, Derbyshire - 20 August 1940 Birmingham, was a Quaker botanist and agrostologist. He was the first curator of the Forest Herbarium at the Imperial Forestry Institute when it was founded in 1924. He attended school at Ilkley in West Yorkshire. In 1891 he joined Kew Gardens as a technical assistant, leaving shortly after for the USA where he enrolled in the botany department at the University of California.