Page 47 - Electrical Engineering Dictionary
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a motor, prime mover, or by the shaft of the  ambient temperature  the temperature
                              synchronous machine.                   of the air or liquid surrounding any electrical
                                                                     part or device. Usually refers to the effect
                              ALU    See arithmetic and logic unit.  of such temperature in aiding or retarding re-
                                                                     moval of heat by radiation and convection
                              AM     See amplitude modulation.       from the part or device in question.
                                                                     ambiguity   in artificial intelligence, the
                              AM to PM conversion   phase variations
                                                                     presence of more than one meaning or possi-
                              of an output signal, due to passing through an
                                                                     bility.
                              active device, where the phase of the output
                              signal varies in response with the amplitude
                                                                     Amdahl’s law    states that the speedup
                              of the input signal.
                                                                     factor of a multiprocessor system is given by
                                                                                         n
                              AM video   the amplitude modulated video
                                                                             S(n) =
                              carrier wave is produced by an amplitude              1 + (n − 1)f
                              modulated video transmitter where the am-
                                                                     wherethereare nprocessorsandf isthefrac-
                              plitude of the wave form varies in step with
                                                                     tion of computational that must be performed
                              the video signal similar to that shown in the
                                                                     sequentially (by one processor alone). The
                              figure.
                                                                     remaining part of the computation is assumed
                                                                     to be divided into n equal parts each executed
                              amateur radio  The practice and study of  by a separate processor but simultaneously.
                              electronic communications as an avocation;  The speedup factor tends to 1/f as n →∞,
                              most often referring to those persons possess-  which demonstrates that under the assump-
                              ing a license earned by examination (in the  tions given, the maximum speedup is con-
                              U.S., the Federal Communications Commis-  strained by the serial fraction.
                              sion grants such licenses).
                                                                     American National Standards Institute
                              ambient field  the background magnetic  (ANSI)    The U.S. organization that rec-
                              field level existing in the environment, with-  ommends standards for metrology, drawing
                              out contribution from specific magnetic field  symbology and numerous other facets for
                              sources.                               products and industries.



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