189,296 research outputs found
Learning to Select, Track, and Generate for Data-to-Text
We propose a data-to-text generation model with two modules, one for tracking
and the other for text generation. Our tracking module selects and keeps track
of salient information and memorizes which record has been mentioned. Our
generation module generates a summary conditioned on the state of tracking
module. Our model is considered to simulate the human-like writing process that
gradually selects the information by determining the intermediate variables
while writing the summary. In addition, we also explore the effectiveness of
the writer information for generation. Experimental results show that our model
outperforms existing models in all evaluation metrics even without writer
information. Incorporating writer information further improves the performance,
contributing to content planning and surface realization.Comment: ACL 201
Large-Margin Determinantal Point Processes
Determinantal point processes (DPPs) offer a powerful approach to modeling
diversity in many applications where the goal is to select a diverse subset. We
study the problem of learning the parameters (the kernel matrix) of a DPP from
labeled training data. We make two contributions. First, we show how to
reparameterize a DPP's kernel matrix with multiple kernel functions, thus
enhancing modeling flexibility. Second, we propose a novel parameter estimation
technique based on the principle of large margin separation. In contrast to the
state-of-the-art method of maximum likelihood estimation, our large-margin loss
function explicitly models errors in selecting the target subsets, and it can
be customized to trade off different types of errors (precision vs. recall).
Extensive empirical studies validate our contributions, including applications
on challenging document and video summarization, where flexibility in modeling
the kernel matrix and balancing different errors is indispensable.Comment: 15 page
Reified Context Models
A classic tension exists between exact inference in a simple model and
approximate inference in a complex model. The latter offers expressivity and
thus accuracy, but the former provides coverage of the space, an important
property for confidence estimation and learning with indirect supervision. In
this work, we introduce a new approach, reified context models, to reconcile
this tension. Specifically, we let the amount of context (the arity of the
factors in a graphical model) be chosen "at run-time" by reifying it---that is,
letting this choice itself be a random variable inside the model. Empirically,
we show that our approach obtains expressivity and coverage on three natural
language tasks
An End-to-End Trainable Neural Network Model with Belief Tracking for Task-Oriented Dialog
We present a novel end-to-end trainable neural network model for
task-oriented dialog systems. The model is able to track dialog state, issue
API calls to knowledge base (KB), and incorporate structured KB query results
into system responses to successfully complete task-oriented dialogs. The
proposed model produces well-structured system responses by jointly learning
belief tracking and KB result processing conditioning on the dialog history. We
evaluate the model in a restaurant search domain using a dataset that is
converted from the second Dialog State Tracking Challenge (DSTC2) corpus.
Experiment results show that the proposed model can robustly track dialog state
given the dialog history. Moreover, our model demonstrates promising results in
producing appropriate system responses, outperforming prior end-to-end
trainable neural network models using per-response accuracy evaluation metrics.Comment: Published at Interspeech 201
Explicit diversification of event aspects for temporal summarization
During major events, such as emergencies and disasters, a large volume of information is reported on newswire and social media platforms. Temporal summarization (TS) approaches are used to automatically produce concise overviews of such events by extracting text snippets from related articles over time. Current TS approaches rely on a combination of event relevance and textual novelty for snippet selection. However, for events that span multiple days, textual novelty is often a poor criterion for selecting snippets, since many snippets are textually unique but are semantically redundant or non-informative. In this article, we propose a framework for the diversification of snippets using explicit event aspects, building on recent works in search result diversification. In particular, we first propose two techniques to identify explicit aspects that a user might want to see covered in a summary for different types of event. We then extend a state-of-the-art explicit diversification framework to maximize the coverage of these aspects when selecting summary snippets for unseen events. Through experimentation over the TREC TS 2013, 2014, and 2015 datasets, we show that explicit diversification for temporal summarization significantly outperforms classical novelty-based diversification, as the use of explicit event aspects reduces the amount of redundant and off-topic snippets returned, while also increasing summary timeliness
Dynamic Entity Representations in Neural Language Models
Understanding a long document requires tracking how entities are introduced
and evolve over time. We present a new type of language model, EntityNLM, that
can explicitly model entities, dynamically update their representations, and
contextually generate their mentions. Our model is generative and flexible; it
can model an arbitrary number of entities in context while generating each
entity mention at an arbitrary length. In addition, it can be used for several
different tasks such as language modeling, coreference resolution, and entity
prediction. Experimental results with all these tasks demonstrate that our
model consistently outperforms strong baselines and prior work.Comment: EMNLP 2017 camera-ready versio
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