释义 |
abac|ˈeɪbæk| [ad. Fr. abaque, ad. L. abacus; cf. aback n.] An alignment chart, a type of nomogram, by means of which the value required is read off by placing a ruler or other straight edge across points representing known values. F. abaque in this sense is used by L. Lalanne, Description et Usage de l' Abaque (1845); in an 1846 Eng. tr. of Lalanne, abaque is rendered by abacus.
1930R. T. Beatty Radio Data Charts 12/1 We have two variable quantities which we multiply together to obtain the third variable, that is, we have to draw scales for three quantities, a, b, c, so that a.b = c... Having thus ascertained the relative sizes of the scales, we can proceed to construct the abac. 1934Jrnl. R. Aeronaut. Soc. XXXVIII. 545 An abac is constructed to give rapid determination of exposure time in reference to time of year, state of sky, colour of subject. 1956Electronic Engin. XXVIII. 533 A rapid method of circuit and transformer design is given in which a series of ‘abacs’ is used to evaluate the design constants. |