The purpose of the present study was to investigate the effect of context on learning idioms among 60 Iranian female advanced English learners. To this end, the researcher assigned the participants to two experimental groups and one control group: Group 1 (first experimental group, the extended-context group), Group 2 (second experimental group, the limited-context group) and Group 3 (control g...

We propose an automatic analyzer for acquiring a time-span tree based on the generative theory of tonal music (GTTM). Although analyzer based on GTTM was previously proposed, it requires manually tweaking the 46 adjustable parameters on a computer screen in order to analyze them properly. We reformalized the time-span reduction in GTTM based on a statistical model called probabilistic context-f...

This paper describes an evolutionary approach to the problem of inferring stochastic context-free grammars from nite language samples. The approach employs a genetic algorithm, with a tness function derived from a minimum description length principle. Solutions to the inference problem are evolved by optimizing the parameters of a covering grammar for a given language sample. We provide details...

We present a hierarchical statistical machine translation system which supports discontinuous constituents. It is based on synchronous linear context-free rewriting systems (SLCFRS), an extension to synchronous context-free grammars in which synchronized non-terminals span k ≥ 1 continuous blocks on either side of the bitext. This extension beyond contextfreeness is motivated by certain complex...

Synchronous Context-Free Grammars (SCFGs), also known as syntax-directed translation schemata [AU69, AU72], are unlike context-free grammars in that they do not have a binary normal form. In general, parsing with SCFGs takes space and time polynomial in the length of the input strings, but with the degree of the polynomial depending on the permutations of the SCFG rules. We consider linear pars...

Unification grammars are widely accepted as an expressive means for describing the structure of natural languages. In general, the recognition problem is undecidable for unification grammars. Even with restricted variants of the formalism, off-line parsable grammars, the problem is computationally hard. We present two natural constraints on unification grammars which limit their expressivity an...

The flexibility and unbounded expressivity of our linguistic abilities is unparalleled in the biological world. Explaining how children acquire this fundamental aspect of human language is a key challenge for cognitive science. A recent corpus study by Yang (2013) has cast doubt on the lexical specificity of children’s productivity, as hypothesized by usage-based approaches. Focusing on determi...

Stochastic context-free grammar (SCFG) based models for non-coding RNA (ncRNA) gene searches are much more powerful than regular grammar based models due to the ability to model intermolecular base pairing. The SCFG models (also known as covariance models) can be scored exactly using dynamic programming techniques. However, the computational resources needed to compute optimal scores using dyna...

Safety verification of while programs is often phrased in terms of inclusions L(A) ⊆ L(B) among regular languages. Antichainbased algorithms have been developed as an efficient method to check such inclusions. In this paper, we generalize the idea of antichain-based verification to verifying safety properties of recursive programs. To be precise, we give an antichain-based algorithm for checkin...

We propose synchronous linear context-free rewriting systems as an extension to synchronous context-free grammars in which synchronized non-terminals span k ≥ 1 continuous blocks on each side of the bitext. Such discontinuous constituents are required for inducing certain alignment configurations that occur relatively frequently in manually annotated parallel corpora and that cannot be generate...