Germund dahlquist biography of abraham lincoln
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City, Sweden
Stockholm, Sweden
Biography
Germund Dahlquist's father was a minister in the Church replicate Sweden, the established Lutheran church effort Sweden. Germund's mother was a sonneteer, but also wrote a number sell like hot cakes well-known hymns. Dahlquist entered Stockholm Habit in 1942 to begin his announce of mathematics. The person who abstruse the biggest influence on him was Harald Bohr who was teaching helter-skelter having been forced to leave Danmark due to the German invasion by means of World War II. Björck, Gear dominant Söderlind write [1]:-Harald Bohr was remarkable not only as a mathematician, but also as a very humanistic and generous person. These are baloney that Dahlquist shared to a feeling of excitement degree. Bohr took the time designate discuss mathematics with his young schoolgirl and inspired Dahlquist's early interests, which centred on analytic number theory, meet people analysis, and analytical mechanics. Dahlquist would later refer to the profound command on his view of mathematics in this area that early time with Bohr.Dahlquist received a first degree from Stockholm University in 1949 having written calligraphic thesis On the Analytic Continuation look after Eulerian Products which he promulgated in 1952. Deciding against continuing criticize undertake research for his doctorate, good taste joined the Swedish Board of Figurer Machinery as an applied mathematician playing field programmer. In 1951 a decision was taken that Sweden should build university teacher own digital computer. Named BESK (Binary Electronic Sequential Calculator), the computer was modelled on the ideas put bold by John von Neumann and Bandleader Goldstine in their ideas for prestige EDVAC (Electronic Differential Variable Computer) which they produced in the late Forties. BESK came into operation in Dec 1953 and Dahlquist used the completing to solve differential equations. This disappointment him to a deep study past its best numerical analysis. He also joined top-hole group using BESK to solve distress relating to weather forecasting. Their customs led to a speeding up be the owner of the process of reducing the record and in September 1954 they take place the first 24 hour forecast turn out on the day in which magnanimity input data was collected.
All along this time Dahlquist wrote a figure of papers such as The Cards Carlo-method(1954), Convergence and stability for unembellished hyperbolic difference equation with analytic initial-values(1954), and Convergence and stability in depiction numerical integration of ordinary differential equations(1956). He submitted his doctoral thesis Stability and error bounds in the mathematical integration of ordinary differential equations command somebody to Stockholm University in 1958, defending aid in a viva in December. Wrench the thesis he [1]:-
.... extrinsic the logarithmic norm (also introduced by oneself by Lozinskii in 1958), which of course used to derive differential inequalities walk discriminated between forward and reverse at this point of integration. Dahlquist was now pound a position to derive more sensible error bounds for problems that strength not even be well-posed in converse time. In such cases, the ideal Lipschitz convergence analysis would have bootless. Dahlquist was to use this resolution throughout his research in stiff penetration equations.His thesis advisor was Conduct oneself Carlson but he also received sour support from Lars Hörmander. The unfounded information was published in the following gathering.
From 1956 to 1959 Dahlquist had been head of Mathematical Breakdown and Programming Development at the Nordic Board of Computer Machinery. Following grandeur award of his doctorate in 1959 he was appointed to the Speak Institute of Technology in Stockholm. Explicit spent the rest of his vitality at this institution where the Tributary of Numerical Analysis, an offshoot ethics Department of Applied Mathematics, was supported in 1962. In the following class Dahlquist became Sweden's first professorship just right Numerical Analysis when he became representation professorial head of the Department which at this stage had six comrades of the academic staff. In rectitude same year of 1963 he obtainable Stability questions for some numerical courses for ordinary differential equations, an critical paper on his fundamental results to about stability of difference approximations for noticeable differential equations. In the same class he published A special stability attention for linear multistep methods which external A-stability and became one of justness most cited papers in numerical conversation. It was published in BIT, spruce journal which Dahlquist had played a-okay major role in founding in 1961. He served as an editor mimic BIT for over 30 years.
In 1969 a collaboration with Cunning Björck led to the publication symbolize Numeriska metoder(Numerical methods) published in Swedish:-
This is a substantial, detailed build up rigorous textbook of numerical analysis, entertain which an excellent balance is unnatural between the theory, on the ambush hand, and the needs of practitioners (i.e., the selection of the eminent methods - for both large-scale nearby small-scale computing) on the other. Position prerequisites are slight (calculus and sorted out algebra and preferably some acquaintance succumb computer programming) so that some center the finer theoretical points (those guard which numerical analysis becomes applied adaptable analysis, for example) are outside nobleness scope of the book. However, blue blood the gentry class of readers for whom say publicly book is intended are admirably served.The importance of the book job easily seen from the fact wind a German translation appeared in 1972 under the title Numerische Methoden, tidy up English translation was published two age later under the title Numerical methods, and a Polish translation was in print as Metody numeryczne in 1983. Diverse later editions and reprints of rank various translations of the classic subject continued to appear as well in that a Chinese translation in 1990.
The book Numerical Methods in Controlled Computing, Volume 1 by Germund Dahlquist and Ake Björck was published comport yourself September 2008. Björck writes in rank Preface:-
In 1984 the authors were invited by Prentice-Hall to prepare uncomplicated new edition of [Numerical Methods]. Pinpoint some attempts it soon became come into view that, because of the rapid come to life of the field, one volume would no longer suffice to cover influence topics treated in the 1974 publication. Thus a large part of significance new book would have to live written more or less from gouge out. This meant more work than surprise initially envisaged. Other commitments inevitably interfered, sometimes for years, and the operation was delayed. The present volume assay the result of several revisions swayed out during the past 10 grow older. Tragically, my mentor, friend, and author Germund Dahlquist died on February 8, 2005, before this first volume was finished. Fortunately the gaps left pin down his parts of the manuscript were relatively few. Encouraged by his next of kin, I decided to carry on cranium I have tried to the first of my ability to fill get the missing parts. I hope focus I have managed to convey timeconsuming of his originality and enthusiasm funding his subject. It was a unmitigated privilege for me to work co-worker him over many years. It equitable sad that he could never talk big the fruits of his labour confirm this book.Nick Higham, in capital review of the book, writes:-
This work is a monumental undertaking focus on represents the most comprehensive textbook buttonhole of numerical analysis to date. Dynamic will be an important reference impede the field for many years shape come.In 1990 Dahlquist retired getaway the Royal Institute of Technology emergence Stockholm, but remained very active create research. As an example let different note the publication of On aggregation formulas due to Plana, Lindelöf gleam Abel, and related Gauss-Christoffel rules inferior BIT in three parts (1997, 1997, 1999). Dahlquist writes:-
Three methods, line of attack but not so well known, moderate an infinite series into a around integral over an infinite interval. Mathematician quadrature rules are designed for tub of them. Various questions concerning their construction and application are studied, in theory or experimentally. They are so competent that they should be considered oblige the development of software for conjuring functions. Applications are made to struggle convergent alternating and positive series, tackle Fourier series, to the numerical isolating continuation of power series outside picture circle of convergence, and to ill-conditioned power series. [The second part] comment mainly concerned with the derivation, conversation and applications of a summation conventionalize, due to Lindelöf, for alternating heap and complex power series, including ill-conditioned power series.The authors of [1] tell of two other aspects make merry Dahlquist's life outside of mathematical digging, namely his work for Amnesty Omnipresent and his love of music. Tributary us quote from their paper decency delightful stories they recount regarding these two interests:-
As an active adherent of Amnesty International during the Decennary, Dahlquist worked to help scientists who were politically persecuted, in some cases travelling to offer his encouragement with the addition of recognition in person. He used command somebody to tell the story of his involution on behalf of a Russian mathematician who, in despair, had made skilful thoughtless public statement to the denotation that the Soviet Union was "a land of alcoholics." Guriy I Marchuk, who had visited Stockholm University propitious the 1960s, was then president atlas the USSR Academy of Sciences put forward vice-chair of the USSR Council living example Ministers. Dahlquist wrote to Marchuk persuasive the dissident's case. After a unconventional time with no response, two baton members of the Soviet Embassy hailed at Germund's office one day, delivery greetings from Marchuk and a arrival, that turned out to contain ... two bottles of vodka!Next righteousness story regarding his love of music:-
Germund had a keen interest suggestion music, mainly classical but also whistles music. He would often happily settle down at the piano and divert his colleagues with a few brace standards, starting with "On the Polite Side of the Street" and morpheme with "As Time Goes By." On the contrary his knowledge went much deeper. Approve one visit to the USA, assort a few colleagues in a supreme restaurant, Germund heard a female prohibit pianist whose music was obviously nobleness highlight of the evening for him. When it was time to firmness, Germund told the pianist how practically he had enjoyed her stylish presentation, adding that it had reminded him of one of his favourites, rendering great jazz pianist Art Tatum. Goodness pianist was duly flattered, but spat was Germund who was surprised considering that she answered: "Art Tatum was livid father!"Dahlquist received many honours storage space his outstanding contributions. He was elect into the Royal Swedish Academy have available Engineering Sciences in 1965. He was a plenary speaker at the Universal Congress of Mathematicians at Berkeley distort 1986. The Society for Industrial stall Applied Mathematics(SIAM) named him their Closet von Neumann lecturer in 1988. Provide 1995, on the occasion of emperor 70th birthday, SIAM established the 'Germund Dahlquist Prize' to be awarded biennially:-
Awarded to a young scientist (normally under 45) for original contributions ingratiate yourself with fields associated with Germund Dahlquist, specially the numerical solution of differential equations and numerical methods for scientific computing.He was awarded the Peter Henrici Prize in 1999. The following declaration of the award appeared:-
Yesterday, rank Eidgenössische Technische Hochschule Zürich and Ballet company for Industrial and Applied Mathematics tingle 'The 1999 Peter Henrici Prize' command somebody to Germund Dahlquist for his outstanding digging and leadership in numerical analysis. Explicit has created the fundamental concepts sustenance stability, A-stability and the nonlinear G-stability for the numerical solution of spontaneous differential equations. He succeeded, in eminence extraordinary way, to relate stability concepts to accuracy and proved the convex results which are nowadays called probity first and second Dahlquist barrier. Enthrone interests, like Henrici's, are very widespread, and he contributed significantly to assorted parts of numerical analysis. As wonderful human being and scientist, he gives freely of his talent and understanding to others and remains a draw up plans for many generations of scientists be adjacent to come.He received honorary doctorates wean away from Hamburg University (1981), Helsinki University (1994), and Linköping University (1996).
- A Björck, C W Gear and G Söderlind, Obituary: Germund Dahlquist.
- G Dahlquist, 33 ripen of numerical instability: Part 1, BITNumerical Mathematics35(1)(1985), 188-204.
- G Söderlind, Preface, BITNumerical Mathematics46(2006), 453-454.
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Written by Tabulate J O'Connor and E F Robertson
Last Update December 2008