| 释义 |
stochastic, a.|stəʊˈkæstɪk|
[ad. Gr. στοχαστικός, f. στοχάζεσθαι to aim at a mark, guess, f. στόχος aim, guess.]
1. Pertaining to conjecture. Now rare or Obs.
1662J. Owen Animadv. on Fiat Lux Pref. 4 But yet there wanted not some beams of light to guide men in the exercise of their Stocastick [sic] faculty. 17..J. Whitefoot in Sir T. Browne's Wks. (1712) I. p. xxxvii, Tho' he [Browne] were no Prophet,..yet in that Faculty which comes nearest it, he excelled, i.e. the Stochastick, wherein he was seldom mistaken, as to future Events. 1720Swift Right of Preced. betw. Physicians & Civilians 11, I am Master of the Stochastick Art, and by Virtue of that, I divine, that those Greek Words..have crept from the Margin into the Text.
2. a. Randomly determined; that follows some random probability distribution or pattern, so that its behaviour may be analysed statistically but not predicted precisely; stochastic process = random process s.v. random a. 1 b.
[1917L. von Bortkiewicz Die Iterationen 3 Die an der Wahrscheinlichkeitstheorie orientierte, somit auf ‘das Gesetz der Grossen Zahlen’ sich gründende Betrachtung empirischer Vielheiten möge als Stochastik..bezeichnet werden. 1923A. A. Tschuprow in Metron II. 461 Every stochastical (1) theory of statistics sees in the empirical statistical numbers images of certain really significant quantities—reflected confuse[d] images blurred..by the Chance. [Note] (1) I use the word ‘stochastical’ as synonymous to ‘based on the theory of probability’—cf. J. Bernoulli, Ars Conjectandi, Basileae, 1713, p. 213 ‘Ars Conjectandi sive Stochastice nobis definitur ars metiendi quam fieri potest exactissimi probabilitates rerum’ and L. v. Bortkiewicz, Die Iterationen. ]1934Proc. Nat. Acad. Sci. XX. 376 A stochastic process is defined by Khintchine to be a one parameter set of chance variables: x(t), -∞ ‹ t < ∞. 1943Rev. Mod. Physics XV. 32 That we should be able to idealize Brownian motion as a Markoff process appears very reasonable. But we should be careful not to conclude too hastily that every stochastic process is necessarily of the Markoff type. 1957New Scientist 20 June 17/3 A new approach to population dynamics was needed, and quite recently this has been provided by J. G. Skellam in the form of a stochastic model which allows the experimentalist to regard his population as a random variable at each instant in time, and is much more flexible than the earlier deterministic equations. 1968P. A. P. Moran Introd. Probability Theory iii. 108 We have already dealt with some simple cases of successive trials in which the probabilities at each stage depend on what has happened before... As the successive stages can be regarded as successive instants of time the sequence of events may be regarded as a ‘random’ or ‘stochastic’..process. 1971Kimura & Ohta Theoret. Aspects Population Genetics iii. 33 In any finite population, gene frequencies are subject to stochastic change due to random sampling of gametes. 1979Sci. Amer. Mar. 64/2 (Advt.), The key was recognizing that the star formation process was ‘stochastic’. That is, new massive stars are not necessarily created adjacent to a supernova; rather, a probability exists for their formation.
b. Mus. Applied (orig. by Yannis Xenakis (b. 1922), Romanian-born Greek composer) to music in which the overall sound structure is determined, but internal details are left to chance or are established mathematically by composer or computer (by the laws of probability or otherwise).
1958Y. Xenakis in Gravesaner Blätter IV. 112 (title) In search of a Stochastic music. Ibid. 121 This glissando passage has been taken as an example, for it comprises every problem of this Stochastic music controlled by arithmetic. 1963T. Pynchon V. x. 292 He got around to talking stochastic music and digital computers with one technician. 1969Sat. Rev. (U.S.) 28 June 56/2 Though much has been written, especially by Xenakis himself, on the technique of ‘stochastic’ music, most of it is utterly unintelligible to the layman. 1975New Yorker 19 May 90/1, I heard a Balinese gamelan one night and the Strasbourg Battery in Yannis Xenakis's latest ‘stochastic’ composition the next. 1978P. Griffiths Conc. Hist. Mod. Music xi. 169 Iannis Xenakis..has also used computers as calculating aids in the composition of his ‘stochastic’ music, where the musical form is made analogous to a stochastic process (i.e. one ruled by laws of probability, such as a sequence of dice throws).
Hence † stoˈchastical a.; stoˈchastically adv.; stochaˈsticity, the property of being stochastic.
a1688Cudworth Freewill (1838) 39 We..may and often do proceed to making a judgment in the case one way or other, stochastically or conjecturally. Ibid. 40 There is need and use of this stochastical judging and opining concerning truth and falsehood in human life. 1947Biometrika XXXIV. 228 The efficiency of any two tests would be identical, in the conditions stated, if the coefficient of correlation between them was {pm}1 because then, of course, they would be functionally, and not stochastically, related. 1968P. A. P. Moran Introd. Probability Theory v. 247 X is said to be ‘stochastically larger’ than Y if F(x) ≤ G(x) for all x. 1971Jrnl. Statistical Computation & Simulation I. 42 Refinement in modelling eventuates a requirement for stochasticity. 1979Nature 9 Aug. 459/2 The explanation..is to the contrary of the conventional explanation of these non-seasonal cycles in terms of demographic stochasticity. |