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Maurice George Kendall  
  
142   01:16 مساءً   date: 9-11-2017
Author : G A Barnard
Book or Source : Maurice George Kendall, in N L Johnson and S Kotz (eds.), Leading personalities in statistical sciences
Page and Part : ...


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Date: 14-11-2017 192
Date: 3-11-2017 59
Date: 22-10-2017 66

Born: 6 September 1907 in Kettering, Northamptonshire, England

Died: 29 March 1983 in Redhill, Surrey, Emgland


Maurice Kendall's father, John Roughton Kendall, was an engineering worker who was brought up in Kettering, while his mother was Georgina Brewer who came from Hertfordshire. As a young boy Maurice sometimes helped his grandfather who owned a public house, The Woolsack, in Kettering. It is rather a miracle that Maurice ever survived to adulthood, for he contracted cerebral meningitis, a disease which at that time was almost always fatal.

In 1914 World War I started and Maurice's father moved to Derby to work for Rolls Royce. It was in Derby that Maurice received his early education but he showed little signs of the great academic achievements which were to come. He sat the entrance examinations for Grammar School but did not gain admission, so he went to Derby Central School. His early interests were in languages but near the end of his secondary schooling he began to show an aptitude for mathematics. The Headmaster of the Central School must be given much credit for making the highly unusual move of arranging for Maurice to attend the Grammar School in his final year.

It is rather remarkable that Maurice's improvement was such that he was awarded a scholarship to study at St John's College, Cambridge. His father, however, did not want his son to go to Cambridge, but rather he wanted him to train as an engineer. Maurice was always extremely grateful to his mother who supported him in wishing to take up the scholarship.

Stuart writes in [4]:-

Life at St John's was in striking contrast to that in Derby, and Maurice's naturally gregarious nature brought him several circles of friends apart from the group reading mathematics at St John's ...

Two interests outside mathematics were cricket and chess. One of his close friends, who shared his interest in chess, was Bronowski. Of the staff, he got to know MacMahon, who was a Fellow of St John's but very elderly, but failed to ever come in contact with Yule at this time despite Yule being a lecturer and Fellow of St John's. Kendall graduated a mathematics Wrangler in 1929 and, in the following year, he passed the Civil Service Examinations and joined the Ministry of Agriculture,

It was at the Ministry of Agriculture that Kendall became involved in statistical work. The quality of this work was such that he was elected a Fellow of the Royal Statistical Society in 1934. One of his first papers came about because of his work at the Ministry of Agriculture and was on factor analysis applied to crop productivity. In 1935 Kendall met Yule for the first time. He spent part of his holidays reading statistics books at the St John's College library and he had to seek out Yule who had the key to the library. Their brief conversation would prove significant for when Yule discussed a revision of his text An Introduction to the Theory of Statistics (first published in 1911) with his publisher the suggestion was made that a second author might be brought in to help Yule. Yule remembered his meeting with Kendall and after discussions joint authorship of a new edition was agreed, the work being undertaken in 1937. It is worth noting that by 1950 the 14th edition of this book had appeared.

This work prompted an even greater enthusiasm for statistics from Kendall who attended lectures in advanced statistical topics at University College London, and began publishing a stream of high quality papers on statistical topics. An advanced treatise on mathematical statistics was proposed in 1939 and Maurice Kendall, Egon Pearson, John Wishart, and others held preliminary discussions. However, the project came to nothing with the outbreak of war since the various authors were dispersed around the country. Kendall remained in London and in 1940 left the Civil Service to take up the post of statistician to the British Chamber of Shipping. As Ord writes in [3]:-

Despite his heavy workload by day and air-raid warden duties by night, he somehow contrived to find time to work on the project [the advanced treatise on mathematical statistics] single-handedly Volume One of the Advanced Theory of Statistics was published in 1943, and Volume Two appeared in1946.

In 1994, more than ten years after Kendall's death, the sixth edition which is now called Kendall's advanced theory of statistics Vol. 1 appeared authored by Alan Stuart and Keith Ord. The preface states:-

It is fifty years since the first edition of Maurice Kendall's Volume 1 appeared, so it is fitting that a new edition sees a major restructuring of The advanced theory that, we hope, remains true to his two goals of presenting a 'systematic treatment of (statistical) theory as it exists at the present time' and keeping the volumes first and foremost as a treatment of 'statistics, not statistical mathematics'.

Kendall continued a remarkable stream of research papers on topics such as the theory of k-statistics, time series, and rank correlation methods and a monograph Rank Correlation in 1948. In 1949 he accepted the second chair of statistics at the London School of Economics. He held this post until 1961 when he resigned to take on the position of Managing Director of a computer consultancy which became SciCon. He later became Chairman of the company.

In 1972, having reached 65 years of age, he retired from SciCon. He most certainly did not retire from work, however, for in that year he took on the role of Director of the World Fertility Survey. The survey was carried out for the United Nations working with the International Statistical Institute. In 1974 he was knighted for his services to statistics, and in 1980 the United Nations awarded him their Peace Medal for his work on the World Fertility Survey.

We have mentioned above some of Kendal's work and some of the textbooks which he wrote. Among other publications which he edited (some jointly) were the two volume Statistical Sources in the United Kingdom (1952, 1957), Dictionary of Statistical Terms (1957) which followed his aim of making new ideas in statistics more widely available, and Bibliography of Statistical Literature which appeared in three volumes (1962, 1965, 1968).

There are many more major texts by Kendall and their importance and popularity is seen by the number of editions which have appeared over the years and continue to appear many years after his death. For example the fifth edition of Rank Correlation appeared in 1990 while we mentioned above that the first edition appeared in 1948. Other monographs are A course in the geometry of n dimensions (1961) which aims to present that part of the theory of n-dimensional geometry which has statistical applications, and to sketch very briefly what those applications are. Indeed the brief aim is achieved for the book only contains 63 pages. In 1963 he published (jointly with P A P Moran) Geometrical probability followed by Time series (1973) in which Kendall states his objectives to bridge the gap between "sophisticated theory and practical applications" in the field of time series and to "treat the subject in its entirety for the benefit of the practising statistician". He also published A course in multivariate analysis and Cluster analysis as well a whole series of articles Studies in the history of probability and statistics.

His character is described in [1] as follows:-

Kendall was above all a great systematizer and organizer, whether of his own and others' theoretical work or of the practical administrative tasks that scientific work requires. ... He was a model in other ways, shunning personal controversy, taking pains to be fair to the young as well as the old, knowing when and how to delegate responsibility, and writing always in a transparent, balanced prose rarely achieved by scientists


 

Articles:

  1. G A Barnard, Maurice George Kendall, in N L Johnson and S Kotz (eds.), Leading personalities in statistical sciences (New York, 1997), 130-132.
  2. K Ord, In memoriam : Maurice George Kendall, 1907-1983, Amer. Statist. 38 (1) (1984), 36-37.
  3. A Stuart, Obituary : Sir Maurice Kendall, 1907-1983, J. Roy. Statist. Soc. Ser. A 147 (1) (1984), 120-122.

 




الجبر أحد الفروع الرئيسية في الرياضيات، حيث إن التمكن من الرياضيات يعتمد على الفهم السليم للجبر. ويستخدم المهندسون والعلماء الجبر يومياً، وتعول المشاريع التجارية والصناعية على الجبر لحل الكثير من المعضلات التي تتعرض لها. ونظراً لأهمية الجبر في الحياة العصرية فإنه يدرّس في المدارس والجامعات في جميع أنحاء العالم. ويُعجب الكثير من الدارسين للجبر بقدرته وفائدته الكبيرتين، إذ باستخدام الجبر يمكن للمرء أن يحل كثيرًا من المسائل التي يتعذر حلها باستخدام الحساب فقط.وجاء اسمه من كتاب عالم الرياضيات والفلك والرحالة محمد بن موسى الخورازمي.


يعتبر علم المثلثات Trigonometry علماً عربياً ، فرياضيو العرب فضلوا علم المثلثات عن علم الفلك كأنهما علمين متداخلين ، ونظموه تنظيماً فيه لكثير من الدقة ، وقد كان اليونان يستعملون وتر CORDE ضعف القوسي قياس الزوايا ، فاستعاض رياضيو العرب عن الوتر بالجيب SINUS فأنت هذه الاستعاضة إلى تسهيل كثير من الاعمال الرياضية.

تعتبر المعادلات التفاضلية خير وسيلة لوصف معظم المـسائل الهندسـية والرياضـية والعلمية على حد سواء، إذ يتضح ذلك جليا في وصف عمليات انتقال الحرارة، جريان الموائـع، الحركة الموجية، الدوائر الإلكترونية فضلاً عن استخدامها في مسائل الهياكل الإنشائية والوصف الرياضي للتفاعلات الكيميائية.
ففي في الرياضيات, يطلق اسم المعادلات التفاضلية على المعادلات التي تحوي مشتقات و تفاضلات لبعض الدوال الرياضية و تظهر فيها بشكل متغيرات المعادلة . و يكون الهدف من حل هذه المعادلات هو إيجاد هذه الدوال الرياضية التي تحقق مشتقات هذه المعادلات.