Roger Fletcher (mathematician)
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Roger Fletcher (mathematician)
Roger Fletcher FRS FRSE (29 January 1939 – 15 July 2016) was a British mathematician and professor at University of Dundee. He was a Fellow of the Society for Industrial and Applied Mathematics (SIAM) and was elected as a Fellow of the Royal Society in 2003. In 2006, he won the Lagrange Prize from SIAM. In 2008, he was awarded a Royal Medal of the Royal Society of Edinburgh. See also * BFGS method * Davidon–Fletcher–Powell formula * Nonlinear conjugate gradient method In numerical optimization, the nonlinear conjugate gradient method generalizes the conjugate gradient method to nonlinear optimization. For a quadratic function \displaystyle f(x) :: \displaystyle f(x)=\, Ax-b\, ^2, the minimum of f is obtained whe ... Bibliography *''Practical methods of optimization'', Wiley, 1987, ; Wiley, 2000, References {{DEFAULTSORT:Fletcher, Roger 1939 births 2016 deaths British mathematicians Fellows of the Royal Society of Edinburgh Fellows of the Royal Society Aca ...
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Fellow Of The Royal Society
Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the judges of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, including mathematics, engineering science, and medical science". Fellow, Fellowship of the Society, the oldest known scientific academy in continuous existence, is a significant honour. It has been awarded to many eminent scientists throughout history, including Isaac Newton (1672), Michael Faraday (1824), Charles Darwin (1839), Ernest Rutherford (1903), Srinivasa Ramanujan (1918), Albert Einstein (1921), Paul Dirac (1930), Winston Churchill (1941), Subrahmanyan Chandrasekhar (1944), Dorothy Hodgkin (1947), Alan Turing (1951), Lise Meitner (1955) and Francis Crick (1959). More recently, fellowship has been awarded to Stephen Hawking (1974), David Attenborough (1983), Tim Hunt (1991), Elizabeth Blackburn (1992), Tim Berners-Lee (2001), Venki R ...
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Royal Society Of Edinburgh
The Royal Society of Edinburgh is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was established in 1783. , there are around 1,800 Fellows. The Society covers a broader selection of fields than the Royal Society of London, including literature and history. Fellowship includes people from a wide range of disciplines – science & technology, arts, humanities, medicine, social science, business, and public service. History At the start of the 18th century, Edinburgh's intellectual climate fostered many clubs and societies (see Scottish Enlightenment). Though there were several that treated the arts, sciences and medicine, the most prestigious was the Society for the Improvement of Medical Knowledge, commonly referred to as the Medical Society of Edinburgh, co-founded by the mathematician Colin Maclaurin in 1731. Maclaurin was unhappy ...
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Mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History One of the earliest known mathematicians were Thales of Miletus (c. 624–c.546 BC); he has been hailed as the first true mathematician and the first known individual to whom a mathematical discovery has been attributed. He is credited with the first use of deductive reasoning applied to geometry, by deriving four corollaries to Thales' Theorem. The number of known mathematicians grew when Pythagoras of Samos (c. 582–c. 507 BC) established the Pythagorean School, whose doctrine it was that mathematics ruled the universe and whose motto was "All is number". It was the Pythagoreans who coined the term "mathematics", and with whom the study of mathematics for its own sake begins. The first woman mathematician recorded by history was Hypati ...
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University Of Dundee
The University of Dundee; . Abbreviated as ''Dund.'' for post-nominals. is a public university, public research university based in Dundee, Scotland. It was founded as a University college#United Kingdom, university college in 1881 with a donation from the prominent Baxter family of History of Dundee#Industrial revolution, textile manufacturers. The institution was, for most of its early existence, a Collegiate university, constituent college of the University of St Andrews alongside United College, St Andrews, United College and St Mary's College, St Andrews, St Mary's College located in the town of St Andrews itself. Following significant expansion, the University of Dundee gained independent university status by royal charter in 1967 while retaining elements of its ancient university, ancient heritage and ancient university governance in Scotland, governance structure. The main campus of the university is located in Dundee's West End, Dundee, West End, which contains many of the ...
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Society For Industrial And Applied Mathematics
Society for Industrial and Applied Mathematics (SIAM) is a professional society dedicated to applied mathematics, computational science, and data science through research, publications, and community. SIAM is the world's largest scientific society devoted to applied mathematics, and roughly two-thirds of its membership resides within the United States. Founded in 1951, the organization began holding annual national meetings in 1954, and now hosts conferences, publishes books and scholarly journals, and engages in advocacy in issues of interest to its membership. Members include engineers, scientists, and mathematicians, both those employed in academia and those working in industry. The society supports educational institutions promoting applied mathematics. SIAM is one of the four member organizations of the Joint Policy Board for Mathematics. Membership Membership is open to both individuals and organizations. By the end of its first full year of operation, SIAM had 130 memb ...
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Davidon–Fletcher–Powell Formula
The Davidon–Fletcher–Powell formula (or DFP; named after William C. Davidon, Roger Fletcher (mathematician), Roger Fletcher, and Michael J. D. Powell) finds the solution to the secant equation that is closest to the current estimate and satisfies the curvature condition. It was the first quasi-Newton method to generalize the secant method to a multidimensional problem. This update maintains the symmetry and positive definiteness of the Hessian matrix. Given a function f(x), its gradient (\nabla f), and positive-definite matrix, positive-definite Hessian matrix B, the Taylor series is :f(x_k+s_k) = f(x_k) + \nabla f(x_k)^T s_k + \frac s^T_k s_k + \dots, and the Taylor series of the gradient itself (secant equation) :\nabla f(x_k+s_k) = \nabla f(x_k) + B s_k + \dots is used to update B. The DFP formula finds a solution that is symmetric, positive-definite and closest to the current approximate value of B_k: :B_= (I - \gamma_k y_k s_k^T) B_k (I - \gamma_k s_k y_k^T) + \gamm ...
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Nonlinear Conjugate Gradient Method
In numerical optimization, the nonlinear conjugate gradient method generalizes the conjugate gradient method to nonlinear optimization. For a quadratic function \displaystyle f(x) :: \displaystyle f(x)=\, Ax-b\, ^2, the minimum of f is obtained when the gradient is 0: :: \nabla_x f=2 A^T(Ax-b)=0. Whereas linear conjugate gradient seeks a solution to the linear equation \displaystyle A^T Ax=A^T b, the nonlinear conjugate gradient method is generally used to find the local minimum of a nonlinear function using its gradient \nabla_x f alone. It works when the function is approximately quadratic near the minimum, which is the case when the function is twice differentiable at the minimum and the second derivative is non-singular there. Given a function \displaystyle f(x) of N variables to minimize, its gradient \nabla_x f indicates the direction of maximum increase. One simply starts in the opposite (steepest descent) direction: :: \Delta x_0=-\nabla_x f (x_0) with an adjustable s ...
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1939 Births
This year also marks the start of the Second World War, the largest and deadliest conflict in human history. Events Below, the events of World War II have the "WWII" prefix. January * January 1 ** Third Reich *** Jews are forbidden to work with Germans. *** The Youth Protection Act was passed on April 30, 1938 and the Working Hours Regulations came into effect. *** The Jews name change decree has gone into effect. ** The rest of the world *** In Spain, it becomes a duty of all young women under 25 to complete compulsory work service for one year. *** First edition of the Vienna New Year's Concert. *** The company of technology and manufacturing scientific instruments Hewlett-Packard, was founded in a garage in Palo Alto, California, by William (Bill) Hewlett and David Packard. This garage is now considered the birthplace of Silicon Valley. *** Sydney, in Australia, records temperature of 45 ˚C, the highest record for the city. *** Philipp Etter took over as Swi ...
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2016 Deaths
This is a list of deaths of notable people, organised by year. New deaths articles are added to their respective month (e.g., Deaths in ) and then linked here. 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 See also * Lists of deaths by day The following pages, corresponding to the Gregorian calendar, list the historical events, births, deaths, and holidays and observances of the specified day of the year: Footnotes See also * Leap year * List of calendars * List of non-standard ... * Deaths by year {{DEFAULTSORT:deaths by year ...
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British Mathematicians
British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, the English language as spoken and written in the United Kingdom or, more broadly, throughout the British Isles * Celtic Britons, an ancient ethno-linguistic group * Brittonic languages, a branch of the Insular Celtic language family (formerly called British) ** Common Brittonic, an ancient language Other uses *''Brit(ish)'', a 2018 memoir by Afua Hirsch *People or things associated with: ** Great Britain, an island ** United Kingdom, a sovereign state ** Kingdom of Great Britain (1707–1800) ** United Kingdom of Great Britain and Ireland (1801–1922) See also * Terminology of the British Isles * Alternative names for the British * English (other) * Britannic (other) * British Isles * Brit (other) * B ...
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Fellows Of The Royal Society Of Edinburgh
The Royal Society of Edinburgh is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was established in 1783. , there are around 1,800 Fellows. The Society covers a broader selection of fields than the Royal Society of London, including literature and history. Fellowship includes people from a wide range of disciplines – science & technology, arts, humanities, medicine, social science, business, and public service. History At the start of the 18th century, Edinburgh's intellectual climate fostered many clubs and societies (see Scottish Enlightenment). Though there were several that treated the arts, sciences and medicine, the most prestigious was the Society for the Improvement of Medical Knowledge, commonly referred to as the Medical Society of Edinburgh, co-founded by the mathematician Colin Maclaurin in 1731. Maclaurin was unhappy ...
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