frequency standard produces an accurate
71Logarithm — The graph of the logarithm to base 2 crosses the x axis (horizontal axis) at 1 and passes through the points with coordinates (2, 1), (4, 2), and (8, 3) …
72Phase-shift keying — Passband modulation v · d · e Analog modulation AM · …
73Metrology — This article is about the science of measurement. For the study of weather see Meteorology. A scientist stands in front of a microarcsecond (1 millionth of 1 arcsecond or 1 millionth of 1/3600 degree) testbed. Metrology is the science of… …
74Sequence alignment — In bioinformatics, a sequence alignment is a way of arranging the sequences of DNA, RNA, or protein to identify regions of similarity that may be a consequence of functional, structural, or evolutionary relationships between the sequences.[1]… …
75Gramophone record — A 12 inch (30 cm) 33⅓ rpm record (left), a 7 inch 45 rpm record (right), and a CD (above) A gramophone record, commonly known as a phonograph record (in American English), vinyl record (in reference to vinyl, the material most commonly used after …
76lighthouse — /luyt hows /, n., pl. lighthouses / how ziz/. 1. a tower or other structure displaying or flashing a very bright light for the guidance of ships in avoiding dangerous areas, in following certain routes, etc. 2. either of two cylindrical metal… …
77biblical literature — Introduction four bodies of written works: the Old Testament writings according to the Hebrew canon; intertestamental works, including the Old Testament Apocrypha; the New Testament writings; and the New Testament Apocrypha. The Old… …
78Normal distribution — This article is about the univariate normal distribution. For normally distributed vectors, see Multivariate normal distribution. Probability density function The red line is the standard normal distribution Cumulative distribution function …
79Quantum mechanics — For a generally accessible and less technical introduction to the topic, see Introduction to quantum mechanics. Quantum mechanics …
80Power factor — For other uses, see Power factor (pistol). The power factor of an AC electric power system is defined as the ratio of the real power flowing to the load over the apparent power in the circuit,[1][2] and is a dimensionless number between 0 and 1… …
