13 research outputs found
Findings of the 2015 Workshop on Statistical Machine Translation
This paper presents the results of the
WMT15 shared tasks, which included a
standard news translation task, a metrics
task, a tuning task, a task for run-time
estimation of machine translation quality,
and an automatic post-editing task. This
year, 68 machine translation systems from
24 institutions were submitted to the ten
translation directions in the standard translation
task. An additional 7 anonymized
systems were included, and were then
evaluated both automatically and manually.
The quality estimation task had three
subtasks, with a total of 10 teams, submitting
34 entries. The pilot automatic postediting
task had a total of 4 teams, submitting
7 entries
Findings of the 2014 Workshop on Statistical Machine Translation
This paper presents the results of the
WMT14 shared tasks, which included a
standard news translation task, a separate
medical translation task, a task for
run-time estimation of machine translation
quality, and a metrics task. This year, 143
machine translation systems from 23 institutions
were submitted to the ten translation
directions in the standard translation
task. An additional 6 anonymized systems
were included, and were then evaluated
both automatically and manually. The
quality estimation task had four subtasks,
with a total of 10 teams, submitting 57 entries
Compositional Morphology for Word Representations and Language Modelling
This paper presents a scalable method for integrating compositional
morphological representations into a vector-based probabilistic language model.
Our approach is evaluated in the context of log-bilinear language models,
rendered suitably efficient for implementation inside a machine translation
decoder by factoring the vocabulary. We perform both intrinsic and extrinsic
evaluations, presenting results on a range of languages which demonstrate that
our model learns morphological representations that both perform well on word
similarity tasks and lead to substantial reductions in perplexity. When used
for translation into morphologically rich languages with large vocabularies,
our models obtain improvements of up to 1.2 BLEU points relative to a baseline
system using back-off n-gram models.Comment: Proceedings of the 31st International Conference on Machine Learning
(ICML
Findings of the 2016 Conference on Machine Translation.
This paper presents the results of the
WMT16 shared tasks, which included five
machine translation (MT) tasks (standard
news, IT-domain, biomedical, multimodal,
pronoun), three evaluation tasks (metrics,
tuning, run-time estimation of MT quality),
and an automatic post-editing task
and bilingual document alignment task.
This year, 102 MT systems from 24 institutions
(plus 36 anonymized online systems)
were submitted to the 12 translation
directions in the news translation task. The
IT-domain task received 31 submissions
from 12 institutions in 7 directions and the
Biomedical task received 15 submissions
systems from 5 institutions. Evaluation
was both automatic and manual (relative
ranking and 100-point scale assessments).
The quality estimation task had three subtasks,
with a total of 14 teams, submitting
39 entries. The automatic post-editing task
had a total of 6 teams, submitting 11 entries
Findings of the 2016 Conference on Machine Translation (WMT16)
This paper presents the results of the
WMT16 shared tasks, which included five
machine translation (MT) tasks (standard
news, IT-domain, biomedical, multimodal,
pronoun), three evaluation tasks (metrics,
tuning, run-time estimation of MT quality),
and an automatic post-editing task
and bilingual document alignment task.
This year, 102 MT systems from 24 institutions
(plus 36 anonymized online systems)
were submitted to the 12 translation
directions in the news translation task. The
IT-domain task received 31 submissions
from 12 institutions in 7 directions and the
Biomedical task received 15 submissions
systems from 5 institutions. Evaluation
was both automatic and manual (relative
ranking and 100-point scale assessments)
Recommended from our members
Refinements in hierarchical phrase-based translation systems
The relatively recently proposed hierarchical phrase-based translation model
for statistical machine translation (SMT) has achieved state-of-the-art performance
in numerous recent translation evaluations. Hierarchical phrase-based
systems comprise a pipeline of modules with complex interactions. In
this thesis, we propose refinements to the hierarchical phrase-based model
as well as improvements and analyses in various modules for hierarchical
phrase-based systems.
We took the opportunity of increasing amounts of available training data
for machine translation as well as existing frameworks for distributed computing
in order to build better infrastructure for extraction, estimation and
retrieval of hierarchical phrase-based grammars. We design and implement
grammar extraction as a series of Hadoop MapReduce jobs. We store the resulting
grammar using the HFile format, which offers competitive trade-offs
in terms of efficiency and simplicity. We demonstrate improvements over two
alternative solutions used in machine translation.
The modular nature of the SMT pipeline, while allowing individual improvements,
has the disadvantage that errors committed by one module are
propagated to the next. This thesis alleviates this issue between the word
alignment module and the grammar extraction and estimation module by
considering richer statistics from word alignment models in extraction. We
use alignment link and alignment phrase pair posterior probabilities for grammar
extraction and estimation and demonstrate translation improvements in
Chinese to English translation.
This thesis also proposes refinements in grammar and language modelling
both in the context of domain adaptation and in the context of the interaction
between first-pass decoding and lattice rescoring. We analyse alternative
strategies for grammar and language model cross-domain adaptation. We
also study interactions between first-pass and second-pass language model in terms of size and n-gram order. Finally, we analyse two smoothing methods
for large 5-gram language model rescoring.
The last two chapters are devoted to the application of phrase-based
grammars to the string regeneration task, which we consider as a means to
study the fluency of machine translation output. We design and implement a
monolingual phrase-based decoder for string regeneration and achieve state-of-the-art
performance on this task. By applying our decoder to the output
of a hierarchical phrase-based translation system, we are able to recover the
same level of translation quality as the translation system
Probabilistic Modelling of Morphologically Rich Languages
This thesis investigates how the sub-structure of words can be accounted for
in probabilistic models of language. Such models play an important role in
natural language processing tasks such as translation or speech recognition,
but often rely on the simplistic assumption that words are opaque symbols. This
assumption does not fit morphologically complex language well, where words can
have rich internal structure and sub-word elements are shared across distinct
word forms.
Our approach is to encode basic notions of morphology into the assumptions of
three different types of language models, with the intention that leveraging
shared sub-word structure can improve model performance and help overcome data
sparsity that arises from morphological processes.
In the context of n-gram language modelling, we formulate a new Bayesian
model that relies on the decomposition of compound words to attain better
smoothing, and we develop a new distributed language model that learns vector
representations of morphemes and leverages them to link together
morphologically related words. In both cases, we show that accounting for word
sub-structure improves the models' intrinsic performance and provides benefits
when applied to other tasks, including machine translation.
We then shift the focus beyond the modelling of word sequences and consider
models that automatically learn what the sub-word elements of a given language
are, given an unannotated list of words. We formulate a novel model that can
learn discontiguous morphemes in addition to the more conventional contiguous
morphemes that most previous models are limited to. This approach is
demonstrated on Semitic languages, and we find that modelling discontiguous
sub-word structures leads to improvements in the task of segmenting words into
their contiguous morphemes.Comment: DPhil thesis, University of Oxford, submitted and accepted 2014.
http://ora.ox.ac.uk/objects/uuid:8df7324f-d3b8-47a1-8b0b-3a6feb5f45c