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Occurring without periodicity; irregular.

a′pe·ri·od′i·cal·ly adv.
a·pe′ri·o·dic′i·ty (-ə-dĭs′ĭ-tē) n.


1. not periodic; not occurring at regular intervals
2. (General Physics) physics
a. (of a system or instrument) being damped sufficiently to reach equilibrium without oscillation
b. (of an oscillation or vibration) not having a regular period
c. (of an electrical circuit) not having a measurable resonant frequency
ˌaperiˈodically adv
aperiodicity n


(ˌeɪ pɪər iˈɒd ɪk)

1. not periodic; irregular.
2. Physics. of or pertaining to vibrations or oscillations with no apparent period.
a`pe•ri•od′i•cal•ly, adv.
a•pe`ri•o•dic′i•ty (-əˈdɪs ɪ ti) n.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.aperiodic - not recurring at regular intervals
periodic, periodical - happening or recurring at regular intervals; "the periodic appearance of the seventeen-year locust"
References in periodicals archive ?
Chaos has been defined as having deterministic aperiodic behavior with initial condition dependence (1).
Servers have previously been developed to provide highly responsive aperiodic performance in periodic, hard deadline environments.
Standard features include real-time bus playback (with the ability to edit out RTs), aperiodic message insertion, error injection/detection, conditional BC branching, 45-bit timetags and "Oneshot" BC operation.
Recall that the normalized ATPs for the aperiodic long-time C- component of the lightning current have the following numerical values [8, 9]: current amplitude [I.
Extension of the method for aperiodic grating or for including surface roughness has been done with success (total field or scattered field combined with TLTMM).
Abstract: This paper presents simple principle for aperiodic tuning of SISO controllers used in autotuning.
However, it may be necessary to create a model of the object for any stable and aperiodic processes in any order whatsoever.
Based on a series of lectures delivered at the 2005 Summer School in Aperiodic Order at the University of Victoria, this graduate text explains how to write a tiling space as an inverse limit, compute the cohomology of various tiling spaces, and construct the pattern- equivariant cohomology of tilings.
in the case where J = 1 - P for some aperiodic power series with nonnegative coefficients P, CONTRIB(n) = {c}.
Elephantine Data Mist (see the following pages), written during the latter half of 1992, began life as what was essentially a motley group of "campfire stories," or, to be more precise, the result of a single low-altitude, high-resolution "scanning pass" over a dense, knotty bundle of countless interwoven imaginary folk tales, some of which came into focus fairly often (but only briefly, and at aperiodic intervals), others of which were seen just once, or completely failed to appear.
Standard features include IRIG-B Receiver (AM or DC/TTL), Generator (DC/TTL), real-time bus playback (with ability to edit out RTs), aperiodic message insertion, error injection/detection, conditional BC branching, 45-bit timetags and "Oneshot" BC operation.
9 shows that during the period of time pressure loss phase currents is aperiodic nature with a tendency to decrease their values, and after recovery voltage characteristic is availability aperiodic components that are smaller, than when starting the motor from rest.