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Edward Colin Cherry  
  
90   02:43 مساءً   date: 26-11-2017
Author : C Wilder
Book or Source : A Conversation with Colin Cherry, San Francisco State University
Page and Part : ...


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Date: 13-12-2017 174
Date: 17-12-2017 227
Date: 7-12-2017 87

Born: 23 June 1914 in St Albans, England

Died: 23 November 1979 in London, England


Colin Cherry was brought up in St Albans, a historic town about 30 km northwest of London, where he attended St Albans School. After leaving school in 1932 he worked as a laboratory assistant with General Electric Company Research Laboratories but took evening classes at Northampton Polytechnic in London, which has now become the City University. He was awarded a B.Sc. in 1936 with first class honours in engineering. He then was appointed to the research staff at the General Electric Company and held this position from 1936 until 1945, although from 1939 to 1945 he was engaged in war work. During World War II he worked for the Ministry of Aircraft Production undertaking research into radar at the Radar Research and Development Establishment in Malvern. He also worked on flying trials.

After the war ended, Cherry was appointed as an assistant lecturer at Manchester University, a post he held for two years before being appointed as a lecturer at the Electrical Engineering Department at Imperial College, London, in 1947. By this time his interests were firmly moving towards communication but he still published papers in electrical engineering such as The Duality between Interlinked Electric and Magnetic Circuits and the Formation of Transformer Equivalent Circuits (1949). Here is the beginning of Cherry's abstract of this paper:-

When making calculations on a circuit, containing both electric impedances and transformers, it is frequently desirable to consider the transformers removed and the constraints they impose replaced by a rearrangement of the impedances connected to their terminals. Such "equivalent circuits" may not always be found; the rules are here established for their formation, and also for checking, by inspection, whether the transformer constraints are removable in this way, in any particular case. It is shown that the equivalent electric circuit of a transformer, having any arrangement of magnetic paths, is derivable from its magnetic circuit by application of the topological principle of duality. This cannot be done if the magnetic circuit is non-planar, as in the case of a transformer possessing four or more windings with leakage couplings; a physically realizable circuit does not then exist.

In 1952 Cherry took sabbatical leave, which he spent at the Massachusetts Institute of Technology in the United States, working there with Norbert Wiener. Back in Imperial College, Cherry was awarded a D.Sc. in engineering in 1956, became a Reader in Telecommunication, then in 1958 became Henry Mark Pease Professor of Telecommunication. He gave his professorial inaugural lecture on Telecommunication as a Social Science. Some of Cherry's ideas were unusual. For example he wrote an article which appeared in the Sheffield Telegraph on 22 August 1963 suggesting a way of reducing the number of car accidents. He proposed that better communication between drivers would reduce accidents, and as a consequence proposed that the government should legislate requiring all cars to be fitted with radio transmitters with a range of 100 metres.

Cherry published over 100 papers, including numerous scientific papers on the theory of electric circuits, telecommunication principles and the psychology of speech and hearing, and he wrote several major books. The first of these influential books was On human communication: A review, a survey, and a criticismpublished in 1957. We quote from a review of the book by Donald J Hillman:-

Mathematics, semantics, cybernetics, linguistics, and psychology, in so far as they involve the passage of information, are here regarded as communication sciences. The aim of this work is to chart and describe connections between various treatments of the topic of communication in these sciences, and to determine whether there is any unity underlying the apparent conceptual diversities. The author is careful to emphasize that strong differences of opinion exist to as whether such unification is possible. The material is presented in the form of essays that may be read independently of each other ...

Another major text by Cherry was World Communication: Threat or Promise published in 1971. In 1978 he was awarded the Marconi International Fellowship:-

To honour notable contributions to the field of communication, both in the scientific/technological sense and in terms of human perception.

Cherry decided to use the Fellowship for two main purposes. One was to sponsor a conference on 'The Foundations of Broadcasting Policy.' This was held in May 1980 at Leeds Castle in south-east England, about six months after Cherry's death. The second use which he decided to make of the Fellowship was to write a book which he had provisionally entitled 'A Second Industrial Revolution?'. He had written the Preface and first three chapters before his death in November 1979. Much material for the remainder of the book had also been collected and the book was completed by one of his former students William E Edmondson and published as The Age of Access: Information Technology and Social Revolution. We quote here two passages from Cherry's Preface. The first passage explains the background to the book:-

This book is based upon lectures which I have been delivering to post-graduate students at Imperial College, London, for several years under the title 'What is Communication?' Soon after starting it became clear that it would be necessary in addition to examine another question, namely: 'What is Technology?', in a similar philosophical and sociological way. The purpose of these lectures has been to help the student to argue his way through the clamour of reports and predictions and the frequent extravagant claims made for modern 'information technology' (meaning, in the main, telecommunication and computing), and to examine what truth there may be in the idea that many today are calling the 'Second Industrial Revolution', which, they say, is now upon us. It must be emphasised that neither in these lectures nor in this book, are we concerned with futurology; no attempts at prediction are made concerning either future technological gadgets or the likely social changes that the future may hold. We confine our attention wholly to principles of argument and to examination of concepts, and leave the reader to deal with the future himself. ... we may assume that at the technological level anything is possible today and in the future; if you can say clearly what it is you want, then there is little doubt that it can be made. The real problems lie elsewhere.

The second quotation concerns public fear of the revolution:-

[T]o the general public some of the reports in the press can often be very alarming, as when the sheer growth in size of the multinational corporations is referred to, as dependent upon modern telecommunication systems and computers; or, when these reports tell us that our children are far more influenced by television than they are by their schooling, and that rising crime statistics are correlated with violence in television programmes. There is nothing new in this; all radically new inventions have given rise to public concern from the moment of their inception - and for very good reason - but none more so than those which affect our powers of communicating, one with another. Anything which touches upon our knowledge or private information is seen as particularly threatening ... So is there anything new about the 'technology of information' that sets it quite apart from all other previous fields? I shall argue in this book that there is, for certain fundamental reasons which have nothing to do with technology qua technology; the reasons lie in the nature of human communication itself which, it will be argued here, is not an 'exchange process' but is always a 'sharing process'.

Colin Cherry travelled widely, and lectured in more than 20 countries. In 1961 he was an invited plenary speaker at the thirteenth British Mathematical Colloquium held in Liverpool and he lectured to the Colloquium On information theory. His death in 1979 at the age of sixty-five, took away a scientist who had identified the major problems of communication theory and was playing a major role in efforts to answer them. He was honoured in 1987 when Imperial College inaugurated 'The Colin Cherry Memorial Lecture.' The information given about the Memorial Lecture series gives the following description of Cherry's contributions:-

He was one of the first to promote the use of TV in the classroom and one of his ideas that was promoted by the press was world government by television. He was also an early promoter of televising parliament. He focused on auditory attention, specifically regarding the cocktail party problem. This concerns the problem of following only one conversation while many other conversations are going on around us. He conducted many experiments trying to explain this. His contributions influenced cognitive science (he is often considered to be a pioneer in this field even though he would never describe himself as a cognitive scientist).


 

Articles:

  1. C Wilder, A Conversation with Colin Cherry, San Francisco State University (July 1976).

 




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.