9,801 research outputs found
Combination Strategies for Semantic Role Labeling
This paper introduces and analyzes a battery of inference models for the
problem of semantic role labeling: one based on constraint satisfaction, and
several strategies that model the inference as a meta-learning problem using
discriminative classifiers. These classifiers are developed with a rich set of
novel features that encode proposition and sentence-level information. To our
knowledge, this is the first work that: (a) performs a thorough analysis of
learning-based inference models for semantic role labeling, and (b) compares
several inference strategies in this context. We evaluate the proposed
inference strategies in the framework of the CoNLL-2005 shared task using only
automatically-generated syntactic information. The extensive experimental
evaluation and analysis indicates that all the proposed inference strategies
are successful -they all outperform the current best results reported in the
CoNLL-2005 evaluation exercise- but each of the proposed approaches has its
advantages and disadvantages. Several important traits of a state-of-the-art
SRL combination strategy emerge from this analysis: (i) individual models
should be combined at the granularity of candidate arguments rather than at the
granularity of complete solutions; (ii) the best combination strategy uses an
inference model based in learning; and (iii) the learning-based inference
benefits from max-margin classifiers and global feedback
Implementable Quantum Classifier for Nonlinear Data
In this Letter, we propose a quantum machine learning scheme for the
classification of classical nonlinear data. The main ingredients of our method
are variational quantum perceptron (VQP) and a quantum generalization of
classical ensemble learning. Our VQP employs parameterized quantum circuits to
learn a Grover search (or amplitude amplification) operation with classical
optimization, and can achieve quadratic speedup in query complexity compared to
its classical counterparts. We show how the trained VQP can be used to predict
future data with {query} complexity. Ultimately, a stronger nonlinear
classifier can be established, the so-called quantum ensemble learning (QEL),
by combining a set of weak VQPs produced using a subsampling method. The
subsampling method has two significant advantages. First, all weak VQPs
employed in QEL can be trained in parallel, therefore, the query complexity of
QEL is equal to that of each weak VQP multiplied by . Second, it
dramatically reduce the {runtime} complexity of encoding circuits that map
classical data to a quantum state because this dataset can be significantly
smaller than the original dataset given to QEL. This arguably provides a most
satisfactory solution to one of the most criticized issues in quantum machine
learning proposals. To conclude, we perform two numerical experiments for our
VQP and QEL, implemented by Python and pyQuil library. Our experiments show
that excellent performance can be achieved using a very small quantum circuit
size that is implementable under current quantum hardware development.
Specifically, given a nonlinear synthetic dataset with features for each
example, the trained QEL can classify the test examples that are sampled away
from the decision boundaries using single and two qubits quantum gates
with accuracy.Comment: 9 page
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