293 research outputs found
The shortest common parameterized supersequence problem
In this paper, we consider the problem of the shortest common parameterized supersequence. In particular, we consider an explicit reduction from the problem to the satisfiability problem. © 2013 Anna Gorbenko and Vladimir Popov
A Dynamic Approach to Rhythm in Language: Toward a Temporal Phonology
It is proposed that the theory of dynamical systems offers appropriate tools
to model many phonological aspects of both speech production and perception. A
dynamic account of speech rhythm is shown to be useful for description of both
Japanese mora timing and English timing in a phrase repetition task. This
orientation contrasts fundamentally with the more familiar symbolic approach to
phonology, in which time is modeled only with sequentially arrayed symbols. It
is proposed that an adaptive oscillator offers a useful model for perceptual
entrainment (or `locking in') to the temporal patterns of speech production.
This helps to explain why speech is often perceived to be more regular than
experimental measurements seem to justify. Because dynamic models deal with
real time, they also help us understand how languages can differ in their
temporal detail---contributing to foreign accents, for example. The fact that
languages differ greatly in their temporal detail suggests that these effects
are not mere motor universals, but that dynamical models are intrinsic
components of the phonological characterization of language.Comment: 31 pages; compressed, uuencoded Postscrip
Computing Covers under Substring Consistent Equivalence Relations
Covers are a kind of quasiperiodicity in strings. A string is a cover of
another string if any position of is inside some occurrence of in
. The shortest and longest cover arrays of have the lengths of the
shortest and longest covers of each prefix of , respectively. The literature
has proposed linear-time algorithms computing longest and shortest cover arrays
taking border arrays as input. An equivalence relation over strings
is called a substring consistent equivalence relation (SCER) iff
implies (1) and (2) for all . In this paper, we generalize the notion of covers for SCERs and prove
that existing algorithms to compute the shortest cover array and the longest
cover array of a string under the identity relation will work for any SCERs
taking the accordingly generalized border arrays.Comment: 16 page
String Periods in the Order-Preserving Model
The order-preserving model (op-model, in short) was introduced quite recently but has already attracted significant attention because of its applications in data analysis. We introduce several types of periods in this setting (op-periods). Then we give algorithms to compute these periods in time O(n), O(n log log n), O(n log^2 log n/log log log n), O(n log n) depending on the type of periodicity. In the most general variant the number of different periods can be as big as Omega(n^2), and a compact representation is needed. Our algorithms require novel combinatorial insight into the properties of such periods
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