1,721,001 research outputs found
Language processing in the era of deep learning
No full textNatural Language Processing is a branch of artificial in- telligence brimful of intricate, sophisticated, and challenging tasks, such as machine translation, question answering, summarization, and so on. Thanks to the recent advances of deep learning, NLP applications have received an unprecedented boost in performance, generating growing in- terest from the Machine Learning community. However, even if recent techniques are starting to reach excellent performance on various tasks, there are still several problems that need to be solved, such as the compu- tational cost, the reproducibility of results, and the lack of interpretability. In this contribution, we provide a high-level overview of recent advances in NLP, the role of Machine Learning, and current research directions
Exploring the feature space of character-level embeddings
No full textRecently, character-level embeddings have become popular in the Natural Language Processing community. These representations provide a description of a word which depends solely on its inner structure, i.e. the sequence of characters. Convolutional and recurrent neural networks are the undisputed protagonists in this context, and they represent the state of the art for many character-level applications. In this work, we firstly compare different neural architectures against adaptive string kernels in simplified scenarios. Then, we propose a hybrid ensemble that injects structural kernel-based features into a neural architecture, providing an efficient and scalable solution. An all-around experimental assessment has been carried out on several string datasets, including biomedical entity recognition and sentiment analysis
On the Use of Knowledge Transfer Techniques for Biomedical Named Entity Recognition †
Full text linkBiomedical named entity recognition (BioNER) is a preliminary task for many other tasks, e.g., relation extraction and semantic search. Extracting the text of interest from biomedical documents becomes more demanding as the availability of online data is increasing. Deep learning models have been adopted for biomedical named entity recognition (BioNER) as deep learning has been found very successful in many other tasks. Nevertheless, the complex structure of biomedical text data is still a challenging aspect for deep learning models. Limited annotated biomedical text data make it more difficult to train deep learning models with millions of trainable parameters. The single-task model, which focuses on learning a specific task, has issues in learning complex feature representations from a limited quantity of annotated data. Moreover, manually constructing annotated data is a time-consuming job. It is, therefore, vital to exploit other efficient ways to train deep learning models on the available annotated data. This work enhances the performance of the BioNER task by taking advantage of various knowledge transfer techniques: multitask learning and transfer learning. This work presents two multitask models (MTMs), which learn shared features and task-specific features by implementing the shared and task-specific layers. In addition, the presented trained MTM is also fine-tuned for each specific dataset to tailor it from a general features representation to a specialized features representation. The presented empirical results and statistical analysis from this work illustrate that the proposed techniques enhance significantly the performance of the corresponding single-task model (STM)
Combining multi-task learning with transfer learning for biomedical named entity recognition
No full textMulti-task learning approaches have shown significant improvements in different fields by training different related tasks simultaneously. The multi-task model learns common features among different tasks where they share some layers. However, it is observed that the multi-task learning approach can suffer performance degradation with respect to single task learning in some of the natural language processing tasks, specifically in sequence labelling problems. To tackle this limitation we formulate a simple but effective approach that combines multi-task learning with transfer learning. We use a simple model that comprises of bidirectional long-short term memory and conditional random field. With this simple model, we are able to achieve better F1-score compared to our single task and the multi-task models as well as state-of-the-art multi-task models
Knowledge Distillation with Teacher Multi-task Model for Biomedical Named Entity Recognition
No full textA Multi-task model (MTM) learns specific features using shared and task specific layers among different tasks, an approach that turned out to be effective in those tasks where limited data is available to train the model. In this research, we utilize this characteristic of MTM using knowledge distillation to enhance the performance of a single task model (STM). STMs have difficulties in learning complex feature representations from a limited amount of annotated data. Distilling knowledge from MTM will help STM to learn more complex feature representations during the training phase. We use feature representations from different layers of a MTM to teach the student model during its training. Our approach shows distinguishable improvements in terms of F1-score with respect to STM. We further performed a statistical analysis to investigate the effect of different teacher models on different student models. We found that a Softmax-based teacher model is more effective for token level knowledge distillation than a CRF-based teacher model
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
