| 释义 |
bottom-up, a. and adv.2
Brit. |ˌbɒtəmˈʌp|, U.S. |ˈˌbɑdəmˈəp|
[‹ bottom n. + up adv.1 Compare later top-down adj. at top n.1 Compounds 3a.]
A. adj.
1. Proceeding from basic elements, facts, or details; involving such an approach to a plan, theory, project, etc.
1942Q. Jrnl. Econ. 56 328 In the long run it is part of the larger question of whether ‘bottom-up’ control can be as efficient as ‘top-down’ control. 1973Jrnl. Financial & Quantitative Anal. 8 702 Since top management's financial planning responsibilities are in this area, we do not want to allow tradeoffs among these decision areas to be obscured by a welter of lower level details. We follow a ‘top-down’ rather than a ‘bottom-up’ approach. 1983Fortune 22 Aug. 104/2 It's a bottom-up look, not top-down—it's deciding how the engineers and others would design this corporation to be the most effective deliverers of our product. 2000N.Y. Rev. Bks. 2 Nov. 57/1 Wills and Bada point out that researchers use two avenues to explore the origins of life, which they characterize as the bottom-up and top-down approaches.
2. spec.
a. Business and Polit. Designating, involving, or relating to an organization or culture in which people lower down a hierarchy have a relatively large amount of influence, control, or responsibility.
1949W. Given Bottom-up Managem. i. 3 Under ‘bottom up’ management the head of a business tries to release the thinking and encourage the initiative of all those down the line. 1954(Community Service, Inc.) (title) Bottom-up democracy, the affiliation of small democratic units for common service. 1979Daedalus Winter 104 In Western Europe..political parties are increasingly tightly bottom-up grassroots organizations. 1984A. Leigh 20 Ways to manage Better (1992) iii. 26 The bottom up approach puts the onus on the employee to do a self appraisal and then discuss it. 1987Times on Sunday (Sydney) 13 Sept. 17/1 Japan's renowned system of ‘bottom-up’ decision-making is being discarded as too cumbersome and slow in times of economic urgency. 1998Housing Agenda Mar. 23/3 Values research offers a chance for genuine consultation and partnership which is inclusive and bottom-up.
b. Esp. in computational linguistics: relating to, designating, or characteristic of an approach which constructs linguistic significance by aggregating individual elements or functional categories of language, or regards it as so composed.
1964Communications Assoc. Computing Machinery 7 80 My analyzer is bottom-up and Warshall's is top-down. 1970Mathematics of Computation 24 235 A broad introduction to the parsing problem, outlining top-down, bottom-up, and catch-as-catch-can approaches to compiling. 1983G. Brown & G. Yule Discourse Analysis vii. 234 We work out the meanings of the words and structure of a sentence and build up a composite meaning for the sentence (i.e. bottom-up processing). 1992Lit. & Ling. Computing 7 116/1 This information can be obtained by extracting significant, although elementary, syntactic structures from the output of the morphologic analyser. The approach that we use is, in a sense, bottom-up.
c. Computing. Designating program writing and development in which the lowest-level functions or modules are written and tested first, and then used to form successively higher-level elements as necessary.
1972O. J. Dahl et al. Structured Programming p. v, Structured programming principles can be equally applied in ‘bottom-up’ as in ‘top-down’ program design. 1985Pract. Computing May 149/1 Basic tends to encourage a bottom-up style of programming on the part of the naive user. 1994Proc. IEEE 3rd Workshop Program Comprehension 170/1 In bottom up development, the programmer starts by implementing the lowest level general purpose utility routines. 1995Computer Weekly 30 Nov. 30/3 The top-downers argue that the bottom-up approach is far too limited.
d. Astron. Designating (a model of) a process of galaxy formation in which smaller astronomical objects aggregate by gravitational attraction to form progressively larger structures.
1984Science 29 June 1385/2 It is a member of a loose and young-looking group that is most naturally interpreted as forming by Lemaître's ‘bottom-up’ scenario. 1986Sci. Amer. July 37/1 The bottom-up model was faced with a severe problem in the late 1970's, when superclusters hundreds of millions of light-years long were discovered. 1990J. Gribbin & M. Rees Cosmic Coincidences (1991) iii. 72 In a so-called bottom-up scenario, objects like dwarf galaxies and globular clusters formed first and the pieces were then grouped together by gravity to make galaxies and clusters. 1999N.Y. Times 26 Jan. d 2/6 Many theorists had subscribed to a simpler idea of ‘bottom-up’ evolution, progressing from stars and galaxies to clusters, on to superclusters.
B. adv. From basic elements, principles, or levels; from the bottom upward.
1984P. H. Winston Artificial Intelligence (ed. 2) x. 340 One possibility is that the information flows bottom up through the various representations, with the computation at each stage depending only on the description produced at the immediately preceding stage. 1991J. Russell in R. Tallis & H. Robinson Pursuit of Mind ii. 32 The parsing mechanism constitutes one independent cognitive module among others, which can be studied in terms of representations that are built from the raw input of the speech stream ‘bottom up’. 2001Independent 4 Apr. (Business Suppl.) 5/5 We invest bottom-up, stock by stock. |