Otto Julius Zobel (1887–1970) was a design engineer who worked for the American Telephone & Telegraph Company (AT&T) in the early part of the 20th century. Zobel's work on filter design was revolutionary and led, in conjunction with the work of John R. Carson, to significant commercial advances for AT&T in the field of frequency division multiplex (FDM) telephone transmissions. Although much of Zobel's work has been superseded by more modern filter designs, it remains the basis of filter theory and his papers are still referenced today. Zobel invented the m-derived filter and the constant-resistance filter, which remains in use. Zobel and Carson helped to establish the nature of noise in electric circuits, concluding that—contrary to mainstream belief—it is not even theoretically possible to filter out noise entirely and that noise will always be a limiting factor in what it is possible to transmit. Thus, they anticipated the later work of Claude Shannon, who showed how the theoretical information rate of a channel is related to the noise of the channel. (more...)
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98:
Trajan, namesake of a forum, a market and a column in Rome, succeeded his adoptive father Nerva as Roman emperor. http://en.wikipedia.org/wiki/Trajan
1813:
The novel Pride and Prejudice by English author Jane Austen was published, using material from an unpublished manuscript that she originally wrote between 1796 and 1797. http://en.wikipedia.org/wiki/Pride_and_Prejudice
1933:
Choudhry Rahmat Ali published a pamphlet entitled "Now or Never" in which he called for the creation of a Muslim state in northwest India that he termed "Pakstan". http://en.wikipedia.org/wiki/Choudhry_Rahmat_Ali
1964:
An unarmed US Air Force T-39 Sabreliner on a training mission was shot down over Erfurt, East Germany, by a Soviet MiG-19, killing all three aboard. http://en.wikipedia.org/wiki/1964_T-39_shootdown_incident
1984:
Tropical Storm Domoina made landfall in southern Mozambique, causing some of the most severe flooding so far recorded in the region. http://en.wikipedia.org/wiki/Tropical_Storm_Domoina
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