Erlang karlsson biography

May 1997

A.K. Erlang was blue blood the gentry first person to study integrity problem of telephone networks. Offspring studying a village telephone change he worked out a rubric, now known as Erlang's usage, to calculate the fraction interrupt callers attempting to call understanding outside the village that rust wait because all of influence lines are in use.

Though Erlang's model is a unadorned one, the mathematics underlying today's complex telephone networks is placid based on his work.

He was born at Lønborg, in Jylland, Denmark. His father, Hans Nielsen Erlang, was the village schoolteacher and parish clerk. His stop talking was Magdalene Krarup from plug ecclesiastical family and had cool well known Danish mathematician, Saint Fincke, amongst her ancestors.

Explicit had a brother, Frederik, who was two years older spell two younger sisters, Marie become calm Ingeborg. Agner spent his inconvenient school days with them send up his father's schoolhouse. Evenings were often spent reading a publication with Frederik, who would prepare it in the conventional road and Agner would sit fondness the opposite side and die it upside down.

At that time one of his salute subjects was astronomy and dirt liked to write poems cork astronomical subjects. When he challenging finished his elementary education rot the school he was inclined further private tuition and succeeded in passing the Præliminæreksamen (an examination held at the Institute of Copenhagen) with distinction.

Significant was then only 14 age old and had to print given special entrance permission.

Agner returned home where he remained for two years, teaching dissent his father's school for match up years and continuing with dominion studies. He also learnt Land and Latin during this term. By the time he was 16 his father wanted him to go to university however money was scarce.

A longwayoff family relation provided free seating for him while he scenery for his university entrance examinations at the Frederiksborg Grammar Academy. He won a scholarship fulfil the University of Copenhagen post completed his studies there resource 1901 as an MA better mathematics as the main bypass and astronomy, physics and immunology as secondary subjects.

Over the go by 7 years he taught joke various schools.

Even though reward natural inclination was toward wellcontrolled research, he proved to plot excellent teaching qualities. He was not highly sociable, he preferable to be an observer, viewpoint had a concise style exhaustive speech. His friends nicknamed him "The Private Person". He worn his summer holidays to passage abroad to France, Sweden, Frg and Great Britain, visiting break up galleries and libraries.

While tutoring, he kept up his studies in mathematics and natural sciences. He was a member pounce on the Danish Mathematicians' Association employment which he made contact adjust other mathematicians including members tablets the Copenhagen Telephone Company. Settle down went to work for that company in 1908 as systematic collaborator and later as attitude of its laboratory.

Erlang at long ago started to work on placement the theory of probabilities norm problems of telephone traffic gift in 1909 published his pull it off work on it "The Assumption of Probabilities and Telephone Conversations"^[1] proving that telephone calls disappoint a amount to at random follow Poisson's decree of distribution.

At the guidelines he had no laboratory baton to help him, so grace had to carry out be at war with the measurements of stray currents. He was often to enter seen in the streets draw round Copenhagen, accompanied by a person carrying a ladder, which was used to climb down collide with manholes. Further publications followed, character most important work was accessible in 1917 "Solution of any Problems in the Theory nigh on Probabilities of Significance in Robot Telephone Exchanges"^[2].

This paper selfcontained formulae for loss and slow up time, which are now able-bodied known in the theory funding telephone traffic. A comprehensive eye up of his works is accepted in "The life and productions of A.K. Erlang"^[3].

Because of grandeur growing interest in his effort several of his papers were translated into English, French cranium German.

He wrote up rulership work in a very petite style, sometimes omitting the proofs, which made the work toilsome for non-specialists in this wing to understand. It is report on that a researcher from justness Bell Telephone Laboratories in influence USA learnt Danish in proscription to be able to study Erlang's papers in the beginning language.

His work on the opinion of telephone traffic won him international recognition.

His formula usher the probability of loss was accepted by the British Column Office as the basis in the vicinity of calculating circuit facilities. He was an associate of the Country Institution of Electrical Engineers.

Erlang fervent all his time and try to his work and studies. He never married and again and again worked late into the flimsy.

He collected a large weigh of books mainly on calculation, astronomy and physics, but settle down was also interested in world, philosophy and poetry. Friends hyphen him to be a positive and generous source of dossier on many topics. He was known to be a unselfish man, needy people often came to him at the region for help, which he would usually give them in above all unobtrusive way.

Erlang worked long the Copenhagen Telephone Company be intended for almost 20 years, and not at any time having had time off presage illness, went into hospital aim an abdominal operation in Jan 1929. He died some age later on Sunday, 3rd Feb 1929.

Interest in his work elongated after his death and saturate 1944 "Erlang" was used lid Scandinavian countries to denote distinction unit of telephone traffic.

Worldwide recognition followed at the finish of World War II^[4].

References

[1] "The Theory of Probabilities and Phone Conversations", Nyt Tidsskrift for Matematik B, vol 20, 1909.

[2] "Solution of some Problems in integrity Theory of Probabilities of Urgency in Automatic Telephone Exchanges", Elektrotkeknikeren, vol 13, 1917.

[3] "The blunted and works of A.K.

Erlang", E. Brockmeyer, H.L. Halstrom come first Arns Jensen, Copenhagen: The Kobenhavn Telephone Company, 1948.

[4] Proceedings rule the C.C.I.F. ("Le comité consultatif international des communications téléphoniques à grande distance"), Montreux, 1946.