no code implementations • EMNLP (WNUT) 2020 • Xiangyu Yang, Giannis Bekoulis, Nikos Deligiannis
To mitigate the noisy nature of the Twitter stream, our system makes use of the COVID-Twitter-BERT (CT-BERT), which is a language model pre-trained on a large corpus of COVID-19 related Twitter messages.
1 code implementation • NAACL (NLP4IF) 2021 • Giannis Bekoulis, Christina Papagiannopoulou, Nikos Deligiannis
Fact Extraction and VERification (FEVER) is a recently introduced task that consists of the following subtasks (i) document retrieval, (ii) sentence retrieval, and (iii) claim verification.
1 code implementation • 17 Mar 2023 • Alexandros Stergiou, Nikos Deligiannis
The success of deep learning models has led to their adaptation and adoption by prominent video understanding methods.
no code implementations • 7 Jul 2022 • Lusine Abrahamyan, Nikos Deligiannis
Patches with high entropy are being processed by the encoder with the largest number of parameters, patches with moderate entropy are processed by the encoder with a moderate number of parameters, and patches with low entropy are processed by the smallest encoder.
no code implementations • 4 Jul 2022 • Abel Díaz Berenguer, Tanmoy Mukherjee, Matias Bossa, Nikos Deligiannis, Hichem Sahli
Successful data representation is a fundamental factor in machine learning based medical imaging analysis.
no code implementations • 20 Jun 2022 • Fawaz Sammani, Boris Joukovsky, Nikos Deligiannis
Given the huge diversity of self-supervised vision pretext tasks, we narrow our focus on understanding paradigms which learn from two views of the same image, and mainly aim to understand the pretext task.
Explainable artificial intelligence
Self-Supervised Learning
1 code implementation • CVPR 2022 • Fawaz Sammani, Tanmoy Mukherjee, Nikos Deligiannis
Current NLE models explain the decision-making process of a vision or vision-language model (a. k. a., task model), e. g., a VQA model, via a language model (a. k. a., explanation model), e. g., GPT.
1 code implementation • 2 Feb 2022 • Lusine Abrahamyan, Anh Minh Truong, Wilfried Philips, Nikos Deligiannis
Further, we minimize the distance between the computed variance maps to enforce the model to produce high variance gradient maps that will lead to the generation of high-resolution images with sharper edges.
no code implementations • 13 Sep 2021 • Xiangyu Yang, Giannis Bekoulis, Nikos Deligiannis
In particular, we experiment with several models to identify (i) whether a tweet is traffic-related or not, and (ii) in the case that the tweet is traffic-related to identify more fine-grained information regarding the event (e. g., the type of the event, where the event happened).
2 code implementations • ICCV 2021 • Lusine Abrahamyan, Valentin Ziatchin, Yiming Chen, Nikos Deligiannis
In compact CNNs, due to the limited number of parameters, abundant features are unlikely to be obtained, and feature diversity becomes an essential characteristic.
Ranked #720 on
Image Classification
on ImageNet
no code implementations • 16 Mar 2021 • Lusine Abrahamyan, Yiming Chen, Giannis Bekoulis, Nikos Deligiannis
In contrast, we advocate that the gradients across the nodes are correlated and propose methods to leverage this inter-node redundancy to improve compression efficiency.
no code implementations • 23 Nov 2020 • Abel Díaz Berenguer, Hichem Sahli, Boris Joukovsky, Maryna Kvasnytsia, Ine Dirks, Mitchel Alioscha-Perez, Nikos Deligiannis, Panagiotis Gonidakis, Sebastián Amador Sánchez, Redona Brahimetaj, Evgenia Papavasileiou, Jonathan Cheung-Wai Chana, Fei Li, Shangzhen Song, Yixin Yang, Sofie Tilborghs, Siri Willems, Tom Eelbode, Jeroen Bertels, Dirk Vandermeulen, Frederik Maes, Paul Suetens, Lucas Fidon, Tom Vercauteren, David Robben, Arne Brys, Dirk Smeets, Bart Ilsen, Nico Buls, Nina Watté, Johan de Mey, Annemiek Snoeckx, Paul M. Parizel, Julien Guiot, Louis Deprez, Paul Meunier, Stefaan Gryspeerdt, Kristof De Smet, Bart Jansen, Jef Vandemeulebroucke
Our motivating application is a real-world problem: COVID-19 classification from CT imaging, for which we present an explainable Deep Learning approach based on a semi-supervised classification pipeline that employs variational autoencoders to extract efficient feature embedding.
no code implementations • 13 Oct 2020 • Esther Rodrigo Bonet, Duc Minh Nguyen, Nikos Deligiannis
Motivated by this, we propose a novel TCF method that leverages GNNs to learn user and item representations, and RNNs to model their temporal dynamics.
1 code implementation • 6 Oct 2020 • Giannis Bekoulis, Christina Papagiannopoulou, Nikos Deligiannis
We study the fact checking problem, which aims to identify the veracity of a given claim.
no code implementations • 2 Oct 2020 • Huynh Van Luong, Boris Joukovsky, Yonina C. Eldar, Nikos Deligiannis
This paper proposes a new deep-unfolding-based network design for the problem of Robust Principal Component Analysis (RPCA) with application to video foreground-background separation.
no code implementations • 7 Sep 2020 • Iman Marivani, Evaggelia Tsiligianni, Bruno Cornelis, Nikos Deligiannis
Multimodal image super-resolution (SR) is the reconstruction of a high resolution image given a low-resolution observation with the aid of another image modality.
no code implementations • 28 Aug 2020 • Tien Huu Do, Duc Minh Nguyen, Giannis Bekoulis, Adrian Munteanu, Nikos Deligiannis
Among the existing GCNNs, many methods can be viewed as instances of a neural message passing motif; features of nodes are passed around their neighbors, aggregated and transformed to produce better nodes' representations.
no code implementations • 18 Mar 2020 • Huynh Van Luong, Boris Joukovsky, Nikos Deligiannis
In this line of research, this paper develops a novel deep recurrent neural network (coined reweighted-RNN) by the unfolding of a reweighted $\ell_1$-$\ell_1$ minimization algorithm and applies it to the task of sequential signal reconstruction.
no code implementations • 21 Jan 2020 • Iman Marivani, Evaggelia Tsiligianni, Bruno Cornelis, Nikos Deligiannis
The deep unfolding architecture is used as a core component of a multimodal framework for guided image super-resolution.
no code implementations • 2 Dec 2019 • Peng Xiao, Bin Liao, Nikos Deligiannis
We present DeepFPC, a novel deep neural network designed by unfolding the iterations of the fixed-point continuation algorithm with one-sided l1-norm (FPC-l1), which has been proposed for solving the 1-bit compressed sensing problem.
no code implementations • 18 Oct 2019 • Iman Marivani, Evaggelia Tsiligianni, Bruno Cornelis, Nikos Deligiannis
Deep learning methods have been successfully applied to various computer vision tasks.
no code implementations • 25 Sep 2019 • Huynh Van Luong, Duy Hung Le, Nikos Deligiannis
In this line of research, this paper develops a novel deep recurrent neural network (coined reweighted-RNN) by unfolding a reweighted l1-l1 minimization algorithm and applies it to the task of sequential signal reconstruction.
no code implementations • 4 Jul 2019 • Evaggelia Tsiligianni, Nikos Deligiannis
In linear inverse problems, the goal is to recover a target signal from undersampled, incomplete or noisy linear measurements.
no code implementations • NAACL 2019 • Duc Minh Nguyen, Tien Huu Do, Robert Calderbank, Nikos Deligiannis
While the correlations among news articles have been shown to be effective cues for online news analysis, existing deep-learning-based methods often ignore this information and only consider each news article individually.
no code implementations • 18 Apr 2019 • Tien Huu Do, Xiao Luo, Duc Minh Nguyen, Nikos Deligiannis
Many methods have been introduced to detect rumours using the content or the social context of news.
1 code implementation • 18 Feb 2019 • Hung Duy Le, Huynh Van Luong, Nikos Deligiannis
We propose a new deep recurrent neural network (RNN) architecture for sequential signal reconstruction.
no code implementations • 29 Jan 2019 • Duc Minh Nguyen, Robert Calderbank, Nikos Deligiannis
We consider matrix completion as a structured prediction problem in a conditional random field (CRF), which is characterized by a maximum a posterior (MAP) inference, and we propose a deep model that predicts the missing entries by solving the MAP inference problem.
no code implementations • 4 Dec 2018 • Duc Minh Nguyen, Evaggelia Tsiligianni, Nikos Deligiannis
Matrix completion is one of the key problems in signal processing and machine learning.
no code implementations • 5 Nov 2018 • Tien Huu Do, Duc Minh Nguyen, Evaggelia Tsiligianni, Angel Lopez Aguirre, Valerio Panzica La Manna, Frank Pasveer, Wilfried Philips, Nikos Deligiannis
Existing inference methods typically use low spatial resolution data collected by fixed monitoring stations and infer the concentration of air pollutants using additional types of data, e. g., meteorological and traffic information.
no code implementations • 4 Jul 2018 • Duc Minh Nguyen, Evaggelia Tsiligianni, Robert Calderbank, Nikos Deligiannis
Specifically, we propose an autoencoder-based matrix completion model that performs prediction of the unknown matrix values as a main task, and manifold learning as an auxiliary task.
no code implementations • 13 May 2018 • Duc Minh Nguyen, Evaggelia Tsiligianni, Nikos Deligiannis
Matrix completion is one of the key problems in signal processing and machine learning, with applications ranging from image pro- cessing and data gathering to classification and recommender sys- tems.
no code implementations • 11 May 2018 • Tien Huu Do, Duc Minh Nguyen, Evaggelia Tsiligianni, Bruno Cornelis, Nikos Deligiannis
Predicting the geographical location of users on social networks like Twitter is an active research topic with plenty of methods proposed so far.
no code implementations • 8 Feb 2018 • Huynh Van Luong, Nikos Deligiannis, Søren Forchhammer, André Kaup
The proposed decomposition solves an $n$-$\ell_1$ cluster-weighted minimization to decompose a sequence of frames (or vectors), into sparse and low-rank components, from compressive measurements.
no code implementations • 21 Dec 2017 • Tien Huu Do, Duc Minh Nguyen, Evaggelia Tsiligianni, Bruno Cornelis, Nikos Deligiannis
In the context of Twitter user geolocation, we realize MENET with textual, network, and metadata features.
1 code implementation • 25 Sep 2017 • Pingfan Song, Xin Deng, João F. C. Mota, Nikos Deligiannis, Pier Luigi Dragotti, Miguel R. D. Rodrigues
This paper proposes a new approach to construct a high-resolution (HR) version of a low-resolution (LR) image given another HR image modality as reference, based on joint sparse representations induced by coupled dictionaries.
1 code implementation • 28 Aug 2017 • Duc Minh Nguyen, Evaggelia Tsiligianni, Nikos Deligiannis
Compressed sensing (CS) is a sampling theory that allows reconstruction of sparse (or compressible) signals from an incomplete number of measurements, using of a sensing mechanism implemented by an appropriate projection matrix.
1 code implementation • 24 Jan 2017 • Huynh Van Luong, Nikos Deligiannis, Jurgen Seiler, Soren Forchhammer, Andre Kaup
In addition, we apply the proposed algorithm to online video foreground and background separation from compressive measurements.
no code implementations • 18 Jul 2016 • Huynh Van Luong, Nikos Deligiannis, Søren Forchhammer, André Kaup
In support of applications involving multiview sources in distributed object recognition using lightweight cameras, we propose a new method for the distributed coding of sparse sources as visual descriptor histograms extracted from multiview images.
no code implementations • 14 Jul 2016 • Nikos Deligiannis, Joao F. C. Mota, Bruno Cornelis, Miguel R. D. Rodrigues, Ingrid Daubechies
Our dictionary learning framework can be tailored both to a single- and a multi-scale framework, with the latter leading to a significant performance improvement.
no code implementations • 20 May 2016 • Nikos Deligiannis, João F. C. Mota, Bruno Cornelis, Miguel R. D. Rodrigues, Ingrid Daubechies
In support of art investigation, we propose a new source sepa- ration method that unmixes a single X-ray scan acquired from double-sided paintings.
no code implementations • 10 May 2016 • Huynh Van Luong, Jurgen Seiler, Andre Kaup, Soren Forchhammer, Nikos Deligiannis
To address this problem, we theoretically study a generic \textcolor{black}{weighted $n$-$\ell_{1}$ minimization} framework and propose a reconstruction algorithm that leverages multiple side information signals (RAMSI).
no code implementations • 13 Sep 2015 • Alhabib Abbas, Nikos Deligiannis, Yiannis Andreopoulos
We create vectors of locally aggregated centers (VLAC) by first clustering SIFT features to obtain local feature centers (LFCs) and then encoding the latter with respect to given centers of local feature centers (CLFCs), extracted from a training set.
1 code implementation • 11 Mar 2015 • Joao F. C. Mota, Nikos Deligiannis, Aswin C. Sankaranarayanan, Volkan Cevher, Miguel R. D. Rodrigues
We propose and analyze an online algorithm for reconstructing a sequence of signals from a limited number of linear measurements.
1 code implementation • 10 Oct 2014 • João F. C. Mota, Nikos Deligiannis, Miguel R. D. Rodrigues
We address the problem of Compressed Sensing (CS) with side information.
2 code implementations • 22 Aug 2014 • Joao F. C. Mota, Nikos Deligiannis, Miguel R. D. Rodrigues
Our bounds and geometrical interpretations reveal that if the prior information has good enough quality, L1-L1 minimization improves the performance of CS dramatically.
Information Theory Information Theory