| 释义 |
ˈindexing, vbl. n.
[f. index v. + -ing1.]
1. The action or process of compiling an index.
1887Athenæum 21 May 667/2 The exhaustive indexing of at least a hundred selected authors.
2. Engin. The intermittent rotation of work through aliquot parts of a complete turn in order that some operation may be performed on it at equal angular intervals; also, the movement of work or of a machine part or tool from one predetermined position to another during machining operations.
1902Internat. Library of Technol. II. §15. 21 Direct indexing is done by the aid of an index plate fastened direct to the index-head spindle; that is, the index plate is moved to obtain the divisions. In indirect indexing, the index plate is normally stationary, and the index-head spindle is rotated by the use of suitable gearing. Indirect indexing is divided into..simple and compound indexing. 1930Engineering 30 May 693/3 During the return stroke, indexing of the worm takes place. 1936Colvin & Stanley Drilling & Surfacing Pract. xxii. 243 The essential thing to remember in all indexing is that the worm wheel on the spindle has 40 teeth and that the worm is a single thread. This means that for every turn of the crank the spindle is rotated 1/40 of a revolution. 1957S. E. Rusinoff Manuf. Processes (ed. 2) xii. 489 In straight in-line indexing, the work piece moves intermittently from one machining station to the next in a straight line; a group of machine tools is assembled into one machine. 1961L. E. Doyle et al. Manuf. Processes xxiv. 587 Linear indexing may be done on a general-purpose milling machine for such jobs as cutting rack teeth. 1964S. Crawford Basic Engin. Processes vi. 172 When using this method of indexing the number of possible divisions is limited to the three-hole circles available on the front index plate. 1966McGraw-Hill Encycl. Sci. & Technol. VII. 408/1 Turret indexing, actuation of the collet, feeding of stock, and spindle clutch operations are automatic.
3. Computers. The automatic increasing or decreasing of the address portion of an instruction, following each execution, by means of an index register, so that a succession of operands is operated on.
1957D. D. McCracken Digital Computer Programming viii. 106 All we really want from the indexing is the sum of the index register contents and the indicated address. Ibid. 109 Locations 1200, 1208, 1216, etc., up to 1272 contain ten numbers... Write a program, using indexing, to compute the sum of the squares of these numbers and store it in 1307. 1961Leeds & Weinberg Computer Programming Fund. iv. 101 Many machines have special circuitry designed to facilitate common operations associated with repetition... In mathematics, indexes, or subscripts, are used to keep track of such processes. As an outgrowth of these terms, the words indexing and index arithmetic have been given to the type of computer instruction which does this job, although indexing may be thought of as a special type of control which also takes over certain tasks of counting from the regular arithmetic instructions. 1970Hull & Day Computers & Probl. Solving 197/2 Index registers have a second important use in what is called automatic address modification or indexing. This occurs when the address of an instruction is modified, just before the instruction is executed, by having the content of an index register added to it.
4. attrib. and Comb., as indexing pin; indexing head = index head (index n. 11).
1901Machinery (N.Y.) Jan. 145/1 A dividing or indexing head... With the tailstock shown..comprises what is commonly known as a pair of index centers. 1944Model Engineer 17 Aug. 157/1 The method..is a modification of the indexing head of a milling machine. 1960H. W. Porter et al. Machine Shop (ed. 2) viii. 294 The indexing head..comes equipped with three index plates. 1964S. Crawford Basic Engin. Processes v. 117 A spring-loaded indexing-pin in the face of the compound-slide accurately locates the post in any one of the four positions. |