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Ferenc Radó  
  
9   02:32 مساءً   date: 20-1-2018
Author : W Benz
Book or Source : Obituary : Ferenc Radó, 1921-1990, Aequationes Math. 43
Page and Part : ...


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Date: 25-1-2018 17
Date: 17-1-2018 10
Date: 22-1-2018 13

Born: 21 May 1921 in Timişoara, Romania

Died: 27 November 1990 in Cluj, Romania


Ferenc Radó was born into a Jewish family in Timişoara. The city had been occupied by Serbia in 1919 but, in the following year, it was allotted by the Treaty of Trianon to Romania. It was therefore a Romanian city when Ferenc was born and it was in Timişoara that he grew up. He attended Jewish primary and secondary school in the city, including the Jewish Lyceum. He was an outstanding pupil who showed his extraordinary potential when he was ranked third out of over one thousand students seeking university entrance in 1939. He entered the Engineering School in Bucharest in that year but his outstanding progress suddenly came to an end. To understand quite how this came about we need to look at the political situation that had been developing in Romania, particularly looking at how the small Jewish minority in Romania were treated.

In eastern Europe, anti-Semitism became widespread in Poland, Hungary, and Romania in the years following World War I. The Jewish community, which formed 4.2 percent of Romania's population in 1930, was subject to discrimination, as anti-Semitism was widespread. Carol II had acceded to the throne in 1930 but the world economic depression caused hard times for the whole population. The Iron Guard was a Romanian fascist organization that fed on anti-Semitism and mystical nationalism. It grew in strength as the economy of the country collapsed but it was suppressed after King Carol II proclaimed a dictatorship in 1938. Despite the ups and downs of the Iron Guards, acts of violence against Jews were rare until the outbreak of World War II. King Carol's position became untenable after Russia, Hungary and Bulgaria captured parts of Romania between June and September of 1940. The Iron Guards returned to a position of power and members of the organisation joined General Ion Antonescu in ruling the country from 1940. A Romanian alliance with Nazi Germany strengthened the hand of the anti-Semites and the country turned on its Jewish citizens. Rado, just having commenced his university course, was prevented from continuing with his university studies.

Worse was to follow for the nineteen year old student. He was sent to a labour camp where he was forced to spend three years [1]:-

Conditions were terrible, nevertheless he created possibilities for himself to study mathematics, usually hidden behind heaps of excavated earth.

By 1944 Antonescu, who ruled the country as a dictator, realised that Germany would lose the war. He, and the democratic opposition in Romania, feared invasion by Russia. On 23 August 1944 Antonescu was overthrown and a new government committed to the Allied war effort against Germany was formed. Russia invaded a week later and there was a number of years of political uncertainty. As far as Rado was concerned, however, the new government proved beneficial for he was allowed to continue his education. He began again his university studies, this time at the University of Cluj. He graduated in 1946 with a degree which qualified him to teach mathematics at secondary schools in Romania. He returned to his home city of Timişoara where he was appointed to teach mathematics at the Jewish Lyceum where he himself had been a student. By 1948 the Communists were in power in Romania, supported by Russian military power, and the school system was nationalised as the communist leaders laid the foundations of a totalitarian regime. Following the educational reforms, Rado taught at a state school in Timişoara. He also taught for a year at the new Pedagogical Institute in the city. In 1950 he was appointed to the University of Cluj. Let us look now at changes that occurred within that institution over the next few years.

Now Cluj (known also by its German name, Klausenburg, and its Hungarian name, Kolozsvár) had, with the rest of Transylvania, been incorporated into Romania in 1919, two years before Rado was born. The University in Cluj, which had been named the Franz Joseph University since 1881, became a Romanian institution and was officially opened as such by King Ferdinand on 1 February 1920. (The Hungarian university in Cluj moved first to Budapest, then to Szeged.) In 1940, Hungary captured the part of Romania containing Cluj, the Hungarian university was moved back from Szeged to Cluj, and the Romanian university in Cluj moved to Sibiu and Timişoara. In 1945, following the end of World War II, the Romanian University returned to Cluj and was named Babes University (after the Romanian natural scientist Victor Babes). It was here that Rado had studied for his degree, gaining his teacher's qualification in 1946. Parts of the Hungarian university in Cluj moved back to Szeged, while that part which remained in Cluj was named the Bolyai University (after János Bolyai). In 1959 the Babes University and the Bolyai University in Cluj joined to became the Babes-Bolyai University and Rado continued to teach there. He was promoted to full professor of mathematics at the Babes-Bolyai University of Cluj in 1969 and he held this position until he retired in 1985.

Let us now look briefly at Rado's mathematical contributions. First we note that as well as publishing under the name Ferenc Rado, he also published papers under the names Francisc Rado and François Rado. His first paper Remarks on an infinite linear system (Romanian) was published in 1953. In 1955 he gave a course on nomography to engineers and technicians. This was published as Lectures on nomography (Romanian) in the following year. D Mazkewitsch writes in a review:-

Treated are: Nomograms for equations with two variables, with three variables (6 types), order and class of nomograms, nomograms with several variables, projective and homographic transformation of nomograms, classification of nomograms.

All nomograms are constructed from determinants. No geometric constructions are given. The presentation is good and well illustrated by solved examples ...

Nomography played an important part in his research during the first part of his career. He published papers such as the following written in Romanian: Two theorems concerning the separation of variables in nomography (1955); On rhomboidal nomograms (1956); The best projective transformation of the scales of alignment nomograms (1957); and Functional equations in connection with nomography (1958).

After this Rado's interests turned towards the algebraic foundations of geometry. He studied [1]:-

... embedding conditions of a semi-web into a Reidemeister web. He continued with non-injective collineations of two Desarguesian projective planes, which led him to ring geometry. ... he became interested in characterising isometries of metric vector spaces with as weak assumptions as possible. He also obtained remarkable results in mathematical programming.

On this latter topic we mention his contributions in 1963 when he introduced the "branch and bound" technique to solve the disjunctive programming problem. E Balas writes in a review:-

The basic principle of the branch and bound technique devised by Land and Doing for the integer programming problem and adapted by Little, Murty, Sweeney, and Karel for solving the travelling salesman problem, is rediscovered here independently, stated in a more general form and used to solve a very important problem: liner programs with logical constraints ...

Finally we note Rado's contributions as on the editorial board of the Journal of Geometry and Aequationes Mathematicae.


 

Articles:

  1. W Benz, Obituary : Ferenc Radó, 1921-1990, Aequationes Math. 43 (2-3) (1992), 120-126.
  2. V Groze, M Tarina and A Vasiu, The life and work of the Professor Francisc Radó (1921-1990), Seminar on Geometry ('Babes-Bolyai' Univ., Cluj-Napoca, 1991), 3-18.
  3. Professor Francisc Radó (1921-1990), Studia Univ. Babes-Bolyai Math. 35 (4) (1990), 103-109.

 




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.