Deep Learning
Probing the Natural Language Inference Task with Automated Reasoning Tools
Marji, Zaid (University of South Florida ) | Nighojkar, Animesh (University of South Florida) | Licato, John (University of South Florida)
The Natural Language Inference (NLI) task is an important task in modern NLP, as it asks a broad question to which many other tasks may be reducible: Given a pair of sentences, does the first entail the second? Although the state-of-the-art on current benchmark datasets for NLI are deep learning-based, it is worthwhile to use other techniques to examine the logical structure of the NLI task. We do so by testing how well a logically-controlled natural language (Attempto Controlled English) can be used to parse NLI sentences, and how well automated theorem provers can reason over the resulting formulae. To improve performance, we develop a set of syntactic and semantic transformation rules. We report their performance, and discuss implications for NLI and logic-based NLP.
Pre-Training A Neural Language Model Improves the Sample Efficiency of an Emergency Room Classification Model
Xu, Binbin (University of Bordeaux ) | Gil-Jardinรฉ, Cรฉdric (University Hospital of Bordeaux) | Thiessard, Frantz ( Universitรฉ de Bordeaux ) | Tellier, Eric (University Hospital of Bordeaux) | Avalos-Fernandez, Marta (Universitรฉ de Bordeaux) | Lagarde, Emmanuel (Universitรฉ de Bordeaux)
To build a French national electronic injury surveillance system based on emergency room visits, we aim to develop a coding system to classify their causes from clinical notes in free-text. Supervised learning techniques have shown good results in this area but require a large amount of expert annotated dataset which is time consuming and costly to obtain. We hypothesize that the Natural Language Processing Transformer model incorporating a generative self-supervised pre-training step can significantly reduce the required number of annotated samples for supervised fine-tuning. In this preliminary study, we test our hypothesis in the simplified problem of predicting whether a visit is the consequence of a traumatic event or not from free-text clinical notes. Using fully re-trained GPT-2 models (without OpenAI pre-trained weights), we assess the gain of applying a self-supervised pre-training phase with unlabeled notes prior to the supervised learning task. Results show that the number of data required to achieve a ginve level of performance (AUC>0.95) was reduced by a factor of 10 when applying pre-training. Namely, for 16 times more data, the fully-supervised model achieved an improvement <1% in AUC. To conclude, it is possible to adapt a multi-purpose neural language model such as the GPT-2 to create a powerful tool for classification of free-text notes with only a small number of labeled samples.
Uncertainty Quantification in Multimodal Ensembles of Deep Learners
Brown, Katherine E. (Tennessee Technological University ) | Bhuiyan, Farzana Ahamed (Tennessee Technological University) | Talbert, Douglas A. (Tennessee Technological University)
Uncertainty quantification in deep learning is an active area of research that examines two primary types of uncertainty in deep learning: epistemic uncertainty and aleatoric uncertainty. Epistemic uncertainty is caused by not having enough data to adequately learn. This creates volatility in the parameters and predictions and causes uncertainty. High epistemic uncertainty can indicate that the modelโs prediction is based on a pattern with which is it not familiar. Aleatoric uncertainty measures the uncertainty due to noise in the data. Two additional active areas of research are multimodal learning and malware analysis. Multimodal learning takes into consideration distinct expressions of features such as different representations (e.g., audio and visual data) or different sampling techniques. Multimodal learning has recently been used in malware analysis to combine multiple types of features. In this work, we present and analyze a novel technique to measure epistemic uncertainty from deep ensembles of modalities. Our results suggest that deep ensembles of modalities provide higher accuracy and lower uncertainty that the constituent single modalities and than the comparable hierarchical multimodal deep learner.
Encoding Neighbor Information into Geographical Embeddings Using Convolutional Neural Networks
Blier-Wong, Christopher (Universitรฉ Laval) | Baillargeon, Jean-Thomas (Universitรฉ Laval) | Cossette, Hรฉlรจne (Universitรฉ Laval) | Lamontagne, Luc (Universitรฉ Laval) | Marceau, Etienne (Universitรฉ Laval)
Geographic information is crucial for estimating the future costs of an insurance contract. It helps identify regions exposed to weather-related events and regions exhibiting higher concentrations of socio-demographic risks such as flood or theft. In actuarial science, the current approach of estimating future costs in a territory is through one-hot encoding of zip codes, postal codes or company-defined polygon levels in statistical learning models. This method has two main drawbacks: it does not share information from similar risk territories and does not share information regarding neighboring areas. We propose the Convolutional Regional Autoencoder model, a method for generating geographical risk encodings using convolutional neural networks. This aims to replace the traditional territory variable for estimating future costs of insurance contracts. Experimental results demonstrate that encodings generated by our approach provide more useful features to predict insurance losses from a real dataset.
EmpTransfo: A Multi-Head Transformer Architecture for Creating Empathetic Dialog Systems
Zandie, Rohola (University of Denver ) | Mahoor, Mohammad H. (University of Denver)
Understanding emotions and responding accordingly is one of the biggest challenges of dialog systems. In this paper, we present EmpTransfo, a multi-head Transformer architecture for creating an empathetic dialog system. We show that utilizing the history of emotions and other metadata can improve the quality of generated conversations by the dialog system. EmpTransfo utilizes state-of-the-art pre-trained models (e.g., OpenAI-GPT) for language generation, though models with different sizes can be used. Our experimental results using a challenging language corpus show that the proposed approach outperforms other models in terms of Hit@1 and PPL.
CorGAN: Correlation-Capturing Convolutional Generative Adversarial Networks for Generating Synthetic Healthcare Records
Torfi, Amirsina (Virginia Polytechnic Institute and State University ) | Fox, Edward A. (Virginia Polytechnic Institute and State University)
Deep learning models have demonstrated high-quality performance in areas such as image classification and speech processing. However, creating a deep learning model using electronic health record (EHR) data, requires addressing particular privacy challenges that are unique to researchers in this domain. This matter focuses attention on generating realistic synthetic data while ensuring privacy. In this paper, we propose a novel framework called correlation-capturing Generative Adversarial Network (corGAN), to generate synthetic healthcare records. In corGAN we utilize Convolutional Neural Networks to capture the correlations between adjacent medical features in the data representation space by combining Convolutional Generative Adversarial Networks and Convolutional Autoencoders. To demonstrate the model fidelity, we show that corGAN generates synthetic data with performance similar to that of real data in various Machine Learning settings such as classification and prediction. We also give a privacy assessment and report on statistical analysis regarding realistic characteristics of the synthetic data.
An Efficient Spiking Neural Network for Recognizing Gestures with a DVS Camera on the Loihi Neuromorphic Processor
Massa, Riccardo, Marchisio, Alberto, Martina, Maurizio, Shafique, Muhammad
Spiking Neural Networks (SNNs), the third generation NNs, have come under the spotlight for machine learning based applications due to their biological plausibility and reduced complexity compared to traditional artificial Deep Neural Networks (DNNs). These SNNs can be implemented with extreme energy efficiency on neuromorphic processors like the Intel Loihi research chip, and fed by event-based sensors, such as DVS cameras. However, DNNs with many layers can achieve relatively high accuracy on image classification and recognition tasks, as the research on learning rules for SNNs for real-world applications is still not mature. The accuracy results for SNNs are typically obtained either by converting the trained DNNs into SNNs, or by directly designing and training SNNs in the spiking domain. Towards the conversion from a DNN to an SNN, we perform a comprehensive analysis of such process, specifically designed for Intel Loihi, showing our methodology for the design of an SNN that achieves nearly the same accuracy results as its corresponding DNN. Towards the usage of the event-based sensors, we design a pre-processing method, evaluated for the DvsGesture dataset, which makes it possible to be used in the DNN domain. Hence, based on the outcome of the first analysis, we train a DNN for the pre-processed DvsGesture dataset, and convert it into the spike domain for its deployment on Intel Loihi, which enables real-time gesture recognition. The results show that our SNN achieves 89.64% classification accuracy and occupies only 37 Loihi cores.
A few resources to get into Deep Learning โ Falconius
Before making some recommendations I'd like to mention that I don't have the absolute truth, this is simply a path that resonates with me because my personality is geared towards more practical resources. I usually like to delve into theory after I know the basics. Now that I made that clear, these are some resources I'd recommend to the young me if I were to start learning this from zero: If you conciously read and watch those two resources you'll have a nice grasp of the theory and practice and you'll be able to apply the knowledge to your own projects or start working for someone else. You won't be an expert after it, give it a little time and experience:P. Of course that there's a gazillion of courses, tutorials, projects, open repositories, workshops and other materials in the web, my advice is to just pick something and have the determination to follow through.
Finding Experts in Transformer Models
Suau, Xavier, Zappella, Luca, Apostoloff, Nicholas
In this work we study the presence of expert units in pre-trained Transformer Models (TM), and how they impact a model's performance. We define expert units to be neurons that are able to classify a concept with a given average precision, where a concept is represented by a binary set of sentences containing the concept (or not). Leveraging the OneSec dataset (Scarlini et al., 2019), we compile a dataset of 1641 concepts that allows diverse expert units in TM to be discovered. We show that expert units are important in several ways: (1) The presence of expert units is correlated ($r^2=0.833$) with the generalization power of TM, which allows ranking TM without requiring fine-tuning on suites of downstream tasks. We further propose an empirical method to decide how accurate such experts should be to evaluate generalization. (2) The overlap of top experts between concepts provides a sensible way to quantify concept co-learning, which can be used for explainability of unknown concepts. (3) We show how to self-condition off-the-shelf pre-trained language models to generate text with a given concept by forcing the top experts to be active, without requiring re-training the model or using additional parameters.
Recent Advances in SQL Query Generation: A Survey
Kalajdjieski, Jovan, Toshevska, Martina, Stojanovska, Frosina
Natural language is hypothetically the best user interface for many domains. However, general models that provide an interface between natural language and any other domain still do not exist. Providing natural language interface to relational databases could possibly attract a vast majority of users that are or are not proficient with query languages. With the rise of deep learning techniques, there is extensive ongoing research in designing a suitable natural language interface to relational databases. This survey aims to overview some of the latest methods and models proposed in the area of SQL query generation from natural language. We describe models with various architectures such as convolutional neural networks, recurrent neural networks, pointer networks, reinforcement learning, etc. Several datasets intended to address the problem of SQL query generation are interpreted and briefly overviewed. In the end, evaluation metrics utilized in the field are presented mainly as a combination of execution accuracy and logical form accuracy.