30,649 research outputs found
An Improved Bees Algorithm for Training Deep Recurrent Networks for Sentiment Classification
Recurrent neural networks (RNNs) are powerful tools for learning information from
temporal sequences. Designing an optimum deep RNN is difficult due to configuration and training
issues, such as vanishing and exploding gradients. In this paper, a novel metaheuristic optimisation
approach is proposed for training deep RNNs for the sentiment classification task. The approach
employs an enhanced Ternary Bees Algorithm (BA-3+), which operates for large dataset classification
problems by considering only three individual solutions in each iteration. BA-3+ combines the
collaborative search of three bees to find the optimal set of trainable parameters of the proposed deep
recurrent learning architecture. Local learning with exploitative search utilises the greedy selection
strategy. Stochastic gradient descent (SGD) learning with singular value decomposition (SVD) aims to
handle vanishing and exploding gradients of the decision parameters with the stabilisation strategy
of SVD. Global learning with explorative search achieves faster convergence without getting trapped
at local optima to find the optimal set of trainable parameters of the proposed deep recurrent learning
architecture. BA-3+ has been tested on the sentiment classification task to classify symmetric and
asymmetric distribution of the datasets from different domains, including Twitter, product reviews,
and movie reviews. Comparative results have been obtained for advanced deep language models and
Differential Evolution (DE) and Particle Swarm Optimization (PSO) algorithms. BA-3+ converged
to the global minimum faster than the DE and PSO algorithms, and it outperformed the SGD, DE,
and PSO algorithms for the Turkish and English datasets. The accuracy value and F1 measure have
improved at least with a 30–40% improvement than the standard SGD algorithm for all classification
datasets. Accuracy rates in the RNN model trained with BA-3+ ranged from 80% to 90%, while the
RNN trained with SGD was able to achieve between 50% and 60% for most datasets. The performance
of the RNN model with BA-3+ has as good as for Tree-LSTMs and Recursive Neural Tensor Networks
(RNTNs) language models, which achieved accuracy results of up to 90% for some datasets. The
improved accuracy and convergence results show that BA-3+ is an efficient, stable algorithm for the
complex classification task, and it can handle the vanishing and exploding gradients problem of
deep RNNs
GIRNet: Interleaved Multi-Task Recurrent State Sequence Models
In several natural language tasks, labeled sequences are available in
separate domains (say, languages), but the goal is to label sequences with
mixed domain (such as code-switched text). Or, we may have available models for
labeling whole passages (say, with sentiments), which we would like to exploit
toward better position-specific label inference (say, target-dependent
sentiment annotation). A key characteristic shared across such tasks is that
different positions in a primary instance can benefit from different `experts'
trained from auxiliary data, but labeled primary instances are scarce, and
labeling the best expert for each position entails unacceptable cognitive
burden. We propose GITNet, a unified position-sensitive multi-task recurrent
neural network (RNN) architecture for such applications. Auxiliary and primary
tasks need not share training instances. Auxiliary RNNs are trained over
auxiliary instances. A primary instance is also submitted to each auxiliary
RNN, but their state sequences are gated and merged into a novel composite
state sequence tailored to the primary inference task. Our approach is in sharp
contrast to recent multi-task networks like the cross-stitch and sluice
network, which do not control state transfer at such fine granularity. We
demonstrate the superiority of GIRNet using three applications: sentiment
classification of code-switched passages, part-of-speech tagging of
code-switched text, and target position-sensitive annotation of sentiment in
monolingual passages. In all cases, we establish new state-of-the-art
performance beyond recent competitive baselines.Comment: Accepted at AAAI 201
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