752 research outputs found
Density Matching for Bilingual Word Embedding
Recent approaches to cross-lingual word embedding have generally been based
on linear transformations between the sets of embedding vectors in the two
languages. In this paper, we propose an approach that instead expresses the two
monolingual embedding spaces as probability densities defined by a Gaussian
mixture model, and matches the two densities using a method called normalizing
flow. The method requires no explicit supervision, and can be learned with only
a seed dictionary of words that have identical strings. We argue that this
formulation has several intuitively attractive properties, particularly with
the respect to improving robustness and generalization to mappings between
difficult language pairs or word pairs. On a benchmark data set of bilingual
lexicon induction and cross-lingual word similarity, our approach can achieve
competitive or superior performance compared to state-of-the-art published
results, with particularly strong results being found on etymologically distant
and/or morphologically rich languages.Comment: Accepted by NAACL-HLT 201
Cross-Lingual Induction and Transfer of Verb Classes Based on Word Vector Space Specialisation
Existing approaches to automatic VerbNet-style verb classification are
heavily dependent on feature engineering and therefore limited to languages
with mature NLP pipelines. In this work, we propose a novel cross-lingual
transfer method for inducing VerbNets for multiple languages. To the best of
our knowledge, this is the first study which demonstrates how the architectures
for learning word embeddings can be applied to this challenging
syntactic-semantic task. Our method uses cross-lingual translation pairs to tie
each of the six target languages into a bilingual vector space with English,
jointly specialising the representations to encode the relational information
from English VerbNet. A standard clustering algorithm is then run on top of the
VerbNet-specialised representations, using vector dimensions as features for
learning verb classes. Our results show that the proposed cross-lingual
transfer approach sets new state-of-the-art verb classification performance
across all six target languages explored in this work.Comment: EMNLP 2017 (long paper
Zero-shot Neural Transfer for Cross-lingual Entity Linking
Cross-lingual entity linking maps an entity mention in a source language to
its corresponding entry in a structured knowledge base that is in a different
(target) language. While previous work relies heavily on bilingual lexical
resources to bridge the gap between the source and the target languages, these
resources are scarce or unavailable for many low-resource languages. To address
this problem, we investigate zero-shot cross-lingual entity linking, in which
we assume no bilingual lexical resources are available in the source
low-resource language. Specifically, we propose pivot-based entity linking,
which leverages information from a high-resource "pivot" language to train
character-level neural entity linking models that are transferred to the source
low-resource language in a zero-shot manner. With experiments on 9 low-resource
languages and transfer through a total of 54 languages, we show that our
proposed pivot-based framework improves entity linking accuracy 17% (absolute)
on average over the baseline systems, for the zero-shot scenario. Further, we
also investigate the use of language-universal phonological representations
which improves average accuracy (absolute) by 36% when transferring between
languages that use different scripts.Comment: To appear in AAAI 201
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