Recurrent neural networks are powerful sequence learners. They are able to incorporate context information in a flexible way, and are robust to localised distortions of the input data. These properties make them well suited to sequence labelling, where input sequences are transcribed with streams of labels. Long short-term memory is an especially promising recurrent architecture, able to bridge long time delays between relevant input and output events, and thereby access long range context. The aim of this thesis is to advance the state-of-the-art in supervised sequence labelling with recurrent networks in general, and long short-term memory in particular. Its two main contributions are (1) a new type of output layer that allows recurrent networks to be trained directly for sequence labelling tasks where the alignment between the inputs and the labels is unknown, and (2) an extension of long short-term memory to multidimensional data, such as images and video sequences. Experimental results are presented on speech recognition, online and offline handwriting recognition, keyword spotting, image segmentation and image classification, demonstrating the advantages of advanced recurrent networks over other sequential algorithms, such as hidden Markov Models.ii

Abstract-Recognising lines of unconstrained handwritten text is a challenging task. The difficulty of segmenting cursive or overlapping characters, combined with the need to exploit surrounding context, has led to low recognition rates for even the best current recognisers. Most recent progress in the field has been made either through improved preprocessing, or through advances in language modelling. Relatively little work has been done on the basic recognition algorithms. Indeed, most systems rely on the same hidden Markov models that have been used for decades in speech and handwriting recognition, despite their well-known shortcomings. This paper proposes an alternative approach based on a novel type of recurrent neural network, specifically designed for sequence labelling tasks where the data is hard to segment and contains long range, bidirectional interdependencies. In experiments on two large unconstrained handwriting databases, our approach achieves word recognition accuracies of 79.7% on online data and 74.1% on offline data, significantly outperforming a state-of-the-art HMM-based system. In addition, we demonstrate the network's robustness to lexicon size, measure the individual influence of its hidden layers, and analyse its use of context. Lastly we provide an in depth discussion of the differences between the network and HMMs, suggesting reasons for the network's superior performance.

In this paper, we apply bidirectional training to a Long Short Term Memory (LSTM) network for the first time. We also present a modified, full gradient version of the LSTM learning algorithm. We discuss the significance of framewise phoneme classification to continuous speech recognition, and the validity of using bidirectional networks for online causal tasks. On the TIMIT speech database, we measure the framewise phoneme classification scores of bidirectional and unidirectional variants of both LSTM and conventional Recurrent Neural Networks (RNNs). We find that bidirectional LSTM outperforms both RNNs and unidirectional LSTM.

Leiomyosarcoma (LMS) of the inferior vena cava (IVC) is an extremely rare malignancy with <400 cases reported. We present a 42-year-old woman with a 3-day history of vague and non-specific abdominal pain. Examination revealed mild tenderness to the epigastrium and right upper quadrant with no other findings. Abdominal ultrasound was performed, which revealed a large hypoechoic mass overlying the IVC. Abdominal computed tomography (CT) was performed which revealed an 8.9 × 7.9 × 9 cm multilobulated lesion encasing the IVC. A CT-guided biopsy was performed which revealed a primary LMS of the IVC. Surgical en bloc excision was performed with an end-to-end Dacron graft for IVC reconstruction. Histopathology confirmed LMS of the vessel wall with negative surgical margins.

Graves, Alex. M.S., Department of Computer Science and Engineering, Wright State University, 2016. GPU-Accelerated Feature Tracking.The motivation of this research is to prove that GPUs can provide significant speedup of long-executing image processing algorithms by way of parallelization and massive data throughput. This thesis accelerates the well-known KLT feature tracking algorithm using OpenCL and an NVidia GeForce GTX 780 GPU. KLT is a fast, efficient and accurate feature tracker but can easily suffer from low frame rates when tracking many features in an HD video sequence. This research explains how KLT could benefit from GPGPU programming and provides the corresponding OpenCL implementation.Additionally, various optimization techniques are emphasized to further boost GPU performance. The experiments conducted prove that when tracking over 500 features in an HD dataset, GPU-based KLT provides a 92% reduction in total runtime compared to a CPU-based implementation. Furthermore, the experiments demonstrate that these features are tracked while maintaining similar accuracy to the CPU results.iv