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Publications

Publications by LIAAD

2021

Automatic generation of timelines for past-web events

Authors
Campos, R; Pasquali, A; Jatowt, A; Mangaravite, V; Jorge, AM;

Publication
The Past Web: Exploring Web Archives

Abstract
Despite significant advances in web archive infrastructures, the problem of exploring the historical heritage preserved by web archives is yet to be solved. Timeline generation emerges in this context as one possible solution for automatically producing summaries of news over time. Thanks to this, users can gain a better sense of reported news events, entities, stories or topics over time, such as getting a summary of the most important news about a politician, an organisation or a locality. Web archives play an important role here by providing access to a historical set of preserved information. This particular characteristic of web archives makes them an irreplaceable infrastructure and a valuable source of knowledge that contributes to the process of timeline generation. Accordingly, the authors of this chapter developed "Tell me Stories" (), a news summarisation system, built on top of the infrastructure of Arquivo.pt-the Portuguese web-archive-to automatically generate a timeline summary of a given topic. In this chapter, we begin by providing a brief overview of the most relevant research conducted on the automatic generation of timelines for past-web events. Next, we describe the architecture and some use cases for "Tell me Stories". Our system demonstrates how web archives can be used as infrastructures to develop innovative services. We conclude this chapter by enumerating open challenges in this field and possible future directions in the general area of temporal summarisation in web archives. © Springer Nature Switzerland AG 2021. All rights reserved.

2021

Do we really need a segmentation step in heart sound classification algorithms?

Authors
Oliveira, J; Nogueira, D; Renna, F; Ferreira, C; Jorge, AM; Coimbra, M;

Publication
2021 43RD ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY (EMBC)

Abstract
Cardiac auscultation is the key screening procedure to detect and identify cardiovascular diseases (CVDs). One of many steps to automatically detect CVDs using auscultation, concerns the detection and delimitation of the heart sound boundaries, a process known as segmentation. Whether to include or not a segmentation step in the signal classification pipeline is nowadays a topic of discussion. Up to our knowledge, the outcome of a segmentation algorithm has been used almost exclusively to align the different signal segments according to the heartbeat. In this paper, the need for a heartbeat alignment step is tested and evaluated over different machine learning algorithms, including deep learning solutions. From the different classifiers tested, Gate Recurrent Unit (GRU) Network and Convolutional Neural Network (CNN) algorithms are shown to be the most robust. Namely, these algorithms can detect the presence of heart murmurs even without a heartbeat alignment step. Furthermore, Support Vector Machine (SVM) and Random Forest (RF) algorithms require an explicit segmentation step to effectively detect heart sounds and murmurs, the overall performance is expected drop approximately 5% on both cases.

2021

Report on the 4th international workshop on narrative extraction from texts (Text2Story 2021) at ECIR 2021

Authors
Campos, R; Jorge, AM; Jatowt, A; Bhatia, S; Finlayson, MA; Cordeiro, JP; Rocha, C; Ribeiro, A; Mansouri, B; Ansah, J; Pasquali, A;

Publication
SIGIR Forum

Abstract

2021

Improving Portuguese Semantic Role Labeling with Transformers and Transfer Learning

Authors
Oliveira, S; Loureiro, D; Jorge, A;

Publication
2021 IEEE 8TH INTERNATIONAL CONFERENCE ON DATA SCIENCE AND ADVANCED ANALYTICS (DSAA)

Abstract
The Natural Language Processing task of determining Who did what to whom is called Semantic Role Labeling. For English, recent methods based on Transformer models have allowed for major improvements in this task over the previous state of the art. However, for low resource languages, like Portuguese, currently available semantic role labeling models are hindered by scarce training data. In this paper, we explore a model architecture with only a pre-trained Transformer-based model, a linear layer, softmax and Viterbi decoding. We substantially improve the state-of-the-art performance in Portuguese by over 15 F1. Additionally, we improve semantic role labeling results in Portuguese corpora by exploiting cross-lingual transfer learning using multilingual pre-trained models, and transfer learning from dependency parsing in Portuguese, evaluating the various proposed approaches empirically.

2021

Transformers and Transfer Learning for Improving Portuguese Semantic Role Labeling

Authors
Oliveira, S; Loureiro, D; Jorge, A;

Publication
CoRR

Abstract

2021

A Survey on Data-Driven Predictive Maintenance for the Railway Industry

Authors
Davari, N; Veloso, B; Costa, GD; Pereira, PM; Ribeiro, RP; Gama, J;

Publication
SENSORS

Abstract
In the last few years, many works have addressed Predictive Maintenance (PdM) by the use of Machine Learning (ML) and Deep Learning (DL) solutions, especially the latter. The monitoring and logging of industrial equipment events, like temporal behavior and fault events-anomaly detection in time-series-can be obtained from records generated by sensors installed in different parts of an industrial plant. However, such progress is incipient because we still have many challenges, and the performance of applications depends on the appropriate choice of the method. This article presents a survey of existing ML and DL techniques for handling PdM in the railway industry. This survey discusses the main approaches for this specific application within a taxonomy defined by the type of task, employed methods, metrics of evaluation, the specific equipment or process, and datasets. Lastly, we conclude and outline some suggestions for future research.

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