14 research outputs found

    SQLformer: Deep Auto-Regressive Query Graph Generation for Text-to-SQL Translation

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    In recent years, there has been growing interest in text-to-SQL translation, which is the task of converting natural language questions into executable SQL queries. This technology is important for its potential to democratize data extraction from databases. However, some of its key hurdles include domain generalisation, which is the ability to adapt to previously unseen databases, and alignment of natural language questions with the corresponding SQL queries. To overcome these challenges, we introduce SQLformer, a novel Transformer architecture specifically crafted to perform text-to-SQL translation tasks. Our model predicts SQL queries as abstract syntax trees (ASTs) in an autoregressive way, incorporating structural inductive bias in the encoder and decoder layers. This bias, guided by database table and column selection, aids the decoder in generating SQL query ASTs represented as graphs in a Breadth-First Search canonical order. Comprehensive experiments illustrate the state-of-the-art performance of SQLformer in the challenging text-to-SQL Spider benchmark. Our implementation is available at https://github.com/AdrianBZG/SQLformerComment: 11 pages, 4 figure

    Unsupervised Fact Verification by Language Model Distillation

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    Unsupervised fact verification aims to verify a claim using evidence from a trustworthy knowledge base without any kind of data annotation. To address this challenge, algorithms must produce features for every claim that are both semantically meaningful, and compact enough to find a semantic alignment with the source information. In contrast to previous work, which tackled the alignment problem by learning over annotated corpora of claims and their corresponding labels, we propose SFAVEL (Self-supervised Fact Verification via Language Model Distillation), a novel unsupervised framework that leverages pre-trained language models to distil self-supervised features into high-quality claim-fact alignments without the need for annotations. This is enabled by a novel contrastive loss function that encourages features to attain high-quality claim and evidence alignments whilst preserving the semantic relationships across the corpora. Notably, we present results that achieve a new state-of-the-art on the standard FEVER fact verification benchmark (+8% accuracy) with linear evaluation

    A Convolutional Neural Network for the Automatic Diagnosis of Collagen VI related Muscular Dystrophies

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    The development of machine learning systems for the diagnosis of rare diseases is challenging mainly due the lack of data to study them. Despite this challenge, this paper proposes a system for the Computer Aided Diagnosis (CAD) of low-prevalence, congenital muscular dystrophies from confocal microscopy images. The proposed CAD system relies on a Convolutional Neural Network (CNN) which performs an independent classification for non-overlapping patches tiling the input image, and generates an overall decision summarizing the individual decisions for the patches on the query image. This decision scheme points to the possibly problematic areas in the input images and provides a global quantitative evaluation of the state of the patients, which is fundamental for diagnosis and to monitor the efficiency of therapies.Comment: Submitted for review to Expert Systems With Application

    Translating synthetic natural language to database queries with a polyglot deep learning framework

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    Abstract: The number of databases as well as their size and complexity is increasing. This creates a barrier to use especially for non-experts, who have to come to grips with the nature of the data, the way it has been represented in the database, and the specific query languages or user interfaces by which data are accessed. These difficulties worsen in research settings, where it is common to work with many different databases. One approach to improving this situation is to allow users to pose their queries in natural language. In this work we describe a machine learning framework, Polyglotter, that in a general way supports the mapping of natural language searches to database queries. Importantly, it does not require the creation of manually annotated data for training and therefore can be applied easily to multiple domains. The framework is polyglot in the sense that it supports multiple different database engines that are accessed with a variety of query languages, including SQL and Cypher. Furthermore Polyglotter supports multi-class queries. Good performance is achieved on both toy and real databases, as well as a human-annotated WikiSQL query set. Thus Polyglotter may help database maintainers make their resources more accessible

    A Convolutional Neural Network for the Automatic Diagnosis of Collagen VI related Muscular Dystrophies

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    The development of machine learning systems for the diagnosis of rare diseases is challenging mainly due the lack of data to study them. Despite this challenge, this paper proposes a system for the Computer Aided Diagnosis (CAD) of low-prevalence, congenital muscular dystrophies from confocal microscopy images. The proposed CAD system relies on a Convolutional Neural Network (CNN) which performs an independent classification for non-overlapping patches tiling the input image, and generates an overall decision summarizing the individual decisions for the patches on the query image. This decision scheme points to the possibly problematic areas in the input images and provides a global quantitative evaluation of the state of the patients, which is fundamental for diagnosis and to monitor the efficiency of therapies.Comment: Submitted for review to Expert Systems With Application

    Synthesis and characterization of M(II) phosphonates (M = Fe, Co, Zn, Mn) as precursors for PEMFCs electrocatalysts

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    Metal phosphonates are promising precursors for applications such as proton conductivity [1] and catalysis [2]. Specifically, upon calcination metal polyphosphates are generated that can be used as non-noble metal alternatives [3] to the highly expensive commercial catalysts (Pt) for proton exchange membrane fuel cells (PEMFCs). In this work, we present the synthesis and characterization of metal polyphosphates obtained from transition divalent metal phosphonates (M= Fe, Mn, Co and Zn) both as monometallic and bimetallic systems (solid solutions). For the preparation of the metal phosphonate precursors, two types of organic linkers were selected, i.e. 2-R,S-hydroxiphosphonoacetic acid [HO3PCH(OH)COOH, HPAA] and nitrilotrismethylenephosphonic acid [N(CH2PO3H2)3, ATMP]. The as synthesized compounds were calcined between 700 and 1000 ºC under N2. Depending on the metal/phosphorous molar ratio in the precursor phases, different compositions were found, the corresponding metal pyrophosphate being the major component according to the crystallographic data. Interestingly, in most of cases the solid solutions were preserved in the final product, for instance Fe-Mn, Fe-Co and Fe-Zn. All calcined materials have been also characterized by XPS, SEM/EDS, FTIR-Raman.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Transition metal hydroxyphosphonoacetates as precursors of electrocatalysts

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    Contribución a CongresosCoordination polymers (PCs) are widely studied due to their applicability in many fields. Among them, metal phosphonates are attractive materials due to their great structural and functional diversity, as proton conductors and/or precursors of electrocatalysts, alternative to the high-cost commercial catalysts based on noble metals, for both, PEMFCs and electrolytic systems. In this research-work, we report the synthesis, characterization and electrochemical properties of several coordination polymers derived from (R,S)-2-hydroxyphosphonoacetic acid (HPAA) with transition metals (MII = Fe, Co, Mn, Ni) as well as their solid solutions. The precursor PCs decompose, upon heating in different conditions, to the corresponding metal oxalate solid solutions, which are then used as intermediate materials for obtaining new Non-Precious Metal Electrocatalysts (NPMCs), by pyrolytic treatment at different temperatures under N2/H2 atmospheres. The electrochemical behavior of these compounds, regarding to the Oxygen Evolution and Reduction Reactions (OER and ORR, respectively), show that the structural features are of considerable importance as to their electrocatalytic activities
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