4,920 research outputs found
Dialogue Act Recognition via CRF-Attentive Structured Network
Dialogue Act Recognition (DAR) is a challenging problem in dialogue
interpretation, which aims to attach semantic labels to utterances and
characterize the speaker's intention. Currently, many existing approaches
formulate the DAR problem ranging from multi-classification to structured
prediction, which suffer from handcrafted feature extensions and attentive
contextual structural dependencies. In this paper, we consider the problem of
DAR from the viewpoint of extending richer Conditional Random Field (CRF)
structural dependencies without abandoning end-to-end training. We incorporate
hierarchical semantic inference with memory mechanism on the utterance
modeling. We then extend structured attention network to the linear-chain
conditional random field layer which takes into account both contextual
utterances and corresponding dialogue acts. The extensive experiments on two
major benchmark datasets Switchboard Dialogue Act (SWDA) and Meeting Recorder
Dialogue Act (MRDA) datasets show that our method achieves better performance
than other state-of-the-art solutions to the problem. It is a remarkable fact
that our method is nearly close to the human annotator's performance on SWDA
within 2% gap.Comment: 10 pages, 4figure
Tensorized Self-Attention: Efficiently Modeling Pairwise and Global Dependencies Together
Neural networks equipped with self-attention have parallelizable computation,
light-weight structure, and the ability to capture both long-range and local
dependencies. Further, their expressive power and performance can be boosted by
using a vector to measure pairwise dependency, but this requires to expand the
alignment matrix to a tensor, which results in memory and computation
bottlenecks. In this paper, we propose a novel attention mechanism called
"Multi-mask Tensorized Self-Attention" (MTSA), which is as fast and as
memory-efficient as a CNN, but significantly outperforms previous
CNN-/RNN-/attention-based models. MTSA 1) captures both pairwise (token2token)
and global (source2token) dependencies by a novel compatibility function
composed of dot-product and additive attentions, 2) uses a tensor to represent
the feature-wise alignment scores for better expressive power but only requires
parallelizable matrix multiplications, and 3) combines multi-head with
multi-dimensional attentions, and applies a distinct positional mask to each
head (subspace), so the memory and computation can be distributed to multiple
heads, each with sequential information encoded independently. The experiments
show that a CNN/RNN-free model based on MTSA achieves state-of-the-art or
competitive performance on nine NLP benchmarks with compelling memory- and
time-efficiency
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