S S symmetry Article An Improved Bees Algorithm for Training Deep Recurrent Networks for Sentiment Classification Sultan Zeybek 1,* , Duc Truong Pham 2, Ebubekir Koç 3 and Aydın Seçer 4 1 Department of Computer Engineering, Fatih Sultan Mehmet Vakif University, Istanbul 34445, Turkey 2 Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, UK;
[email protected] 3 Department of Biomedical Engineering, Fatih Sultan Mehmet Vakif University, Istanbul 34445, Turkey;
[email protected] 4 Department of Mathematical Engineering, Yildiz Technical University, Istanbul 34220, Turkey;
[email protected] * Correspondence:
[email protected] Abstract: 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 Citation: Zeybek, S.; Pham, D. T.; handle vanishing and exploding gradients of the decision parameters with the stabilisation strategy Koç, E.; Seçer, A. An Improved Bees of SVD. Global learning with explorative search achieves faster convergence without getting trapped Algorithm for Training Deep at local optima to find the optimal set of trainable parameters of the proposed deep recurrent learning Recurrent Networks for Sentiment architecture.