599 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- National and Kapodistrian University of AthensGR24 papers
- National Technical University of AthensGR11 papers
- Athena Research and Innovation Center In Information Communication & Knowledge TechnologiesGR9 papers
- Athens State UniversityUS7 papers
- Centre National de la Recherche ScientifiqueFR7 papers
- Centrum Wiskunde & InformaticaNL7 papers
- Delft University of TechnologyNL7 papers
- École PolytechniqueFR7 papers
- University College LondonGB7 papers
- University of OxfordGB7 papers
- Laboratoire d'Informatique de l'École PolytechniqueFR6 papers
- University of AmsterdamNL6 papers
27 papers · 1 filter
Preconditioners for Fractional Diffusion Equations Based on the Spectral Symbol
Nikos Barakitis, Sven-Erik Ekström, Paris Vassalos
It is well known that the discretization of fractional diffusion equations (FDEs) with fractional derivatives , using the so-called weighted and shifted Grünwald formula…
On clustering uncertain and structured data with Wasserstein barycenters and a geodesic criterion for the number of clusters
G. I. Papayiannis, G. N. Domazakis, D. Drivaliaris +3
In this work clustering schemes for uncertain and structured data are considered relying on the notion of Wasserstein barycenters, accompanied by appropriate clustering indices bas…
A Matrix-Less Method to Approximate the Spectrum and the Spectral Function of Toeplitz Matrices with Complex Eigenvalues
Sven-Erik Ekström, Paris Vassalos
It is known that the generating function of a sequence of Toeplitz matrices may not describe the asymptotic distribution of the eigenvalues of if is…
Enabling Opportunistic Users in Multi-Tenant IoT Systems using Decentralized Identifiers and Permissioned Blockchains
Nikos Fotiou, Iakovos Pittaras, Vasilios A. Siris +1
In this work, we leverage advances in decentralized identifiers and permissioned blockchains to build a flexible user authentication and authorization mechanism that offers enhance…
Bayesian models for prediction of the set-difference in volleyball
Ioannis Ntzoufras, Vasilis Palaskas, Sotiris Drikos
The aim of this paper is to study and develop Bayesian models for the analysis of volleyball match outcomes as recorded by the set-difference. Due to the peculiarity of the outcome…
Cost Sharing over Combinatorial Domains: Complement-Free Cost Functions and Beyond
Georgios Birmpas, Evangelos Markakis, Guido Schäfer
We study mechanism design for combinatorial cost sharing. Imagine that multiple items or services are available to be shared among a set of interested agents. The outcome of a mech…
Climate Policy under Spatial Heat Transport: Cooperative and Noncooperative Regional Outcomes
Yongyang Cai, William Brock, Anastasios Xepapadeas +1
We build a novel stochastic dynamic regional integrated assessment model (IAM) of the climate and economic system including a number of important climate science elements that are…
SumQE: a BERT-based Summary Quality Estimation Model
Stratos Xenouleas, Prodromos Malakasiotis, Marianna Apidianaki +1
We propose SumQE, a novel Quality Estimation model for summarization based on BERT. The model addresses linguistic quality aspects that are only indirectly captured by content-base…
Attention-based method for categorizing different types of online harassment language
Christos Karatsalos, Yannis Panagiotakis
In the era of social media and networking platforms, Twitter has been doomed for abuse and harassment toward users specifically women. Monitoring the contents including sexism and…
Multiple Birds with One Stone: Beating for EFX and GMMS via Envy Cycle Elimination
Georgios Amanatidis, Apostolos Ntokos, Evangelos Markakis
Several relaxations of envy-freeness, tailored to fair division in settings with indivisible goods, have been introduced within the last decade. Due to the lack of general existenc…
Revisiting the Graph Isomorphism Problem with Semidefinite Programming
Giannis Nikolentzos, Michalis Vazirgiannis
It is well-known that the graph isomorphism problem can be posed as an equivalent problem of determining whether an auxiliary graph structure contains a clique of specific order. H…
Clustering Multivariate Data using Factor Analytic Bayesian Mixtures with an Unknown Number of Components
Panagiotis Papastamoulis
Recent work on overfitting Bayesian mixtures of distributions offers a powerful framework for clustering multivariate data using a latent Gaussian model which resembles the factor…
Detecting Missing Dependencies and Notifiers in Puppet Programs
Thodoris Sotiropoulos, Dimitris Mitropoulos, Diomidis Spinellis
Puppet is a popular computer system configuration management tool. It provides abstractions that enable administrators to setup their computer systems declaratively. Its use suffer…
A Survey on Biomedical Image Captioning
Vasiliki Kougia, John Pavlopoulos, Ion Androutsopoulos
Image captioning applied to biomedical images can assist and accelerate the diagnosis process followed by clinicians. This article is the first survey of biomedical image captionin…
Extreme Multi-Label Legal Text Classification: A case study in EU Legislation
Ilias Chalkidis, Manos Fergadiotis, Prodromos Malakasiotis +2
We consider the task of Extreme Multi-Label Text Classification (XMTC) in the legal domain. We release a new dataset of 57k legislative documents from EURLEX, the European Union's…
Interledger Smart Contracts for Decentralized Authorization to Constrained Things
Vasilios A. Siris, Dimitrios Dimopoulos, Nikos Fotiou +2
We present models that utilize smart contracts and interledger mechanisms to provide decentralized authorization for constrained IoT devices. The models involve different tradeoffs…
OAuth 2.0 meets Blockchain for Authorization in Constrained IoT Environments
Vasilios A. Siris, Dimitrios Dimopoulos, Nikos Fotiou +2
We present models for utilizing blockchain and smart contract technology with the widely used OAuth 2.0 open authorization framework to provide delegated authorization for constrai…
High-dimensional variable selection via low-dimensional adaptive learning
Christian Staerk, Maria Kateri, Ioannis Ntzoufras
A stochastic search method, the so-called Adaptive Subspace (AdaSub) method, is proposed for variable selection in high-dimensional linear regression models. The method aims at fin…
Semantic Source Code Models Using Identifier Embeddings
Vasiliki Efstathiou, Diomidis Spinellis
The emergence of online open source repositories in the recent years has led to an explosion in the volume of openly available source code, coupled with metadata that relate to a v…
Energy-based Self-attentive Learning of Abstractive Communities for Spoken Language Understanding
Guokan Shang, Antoine Jean-Pierre Tixier, Michalis Vazirgiannis +1
Abstractive community detection is an important spoken language understanding task, whose goal is to group utterances in a conversation according to whether they can be jointly sum…
Evaluation of Greek Word Embeddings
Stamatis Outsios, Christos Karatsalos, Konstantinos Skianis +1
Since word embeddings have been the most popular input for many NLP tasks, evaluating their quality is of critical importance. Most research efforts are focusing on English word em…
SEQ^3: Differentiable Sequence-to-Sequence-to-Sequence Autoencoder for Unsupervised Abstractive Sentence Compression
Christos Baziotis, Ion Androutsopoulos, Ioannis Konstas +1
Neural sequence-to-sequence models are currently the dominant approach in several natural language processing tasks, but require large parallel corpora. We present a sequence-to-se…
On the Feasibility of Transfer-learning Code Smells using Deep Learning
Tushar Sharma, Vasiliki Efstathiou, Panos Louridas +1
Context: A substantial amount of work has been done to detect smells in source code using metrics-based and heuristics-based methods. Machine learning methods have been recently ap…
Does Unit-Tested Code Crash? A Case Study of Eclipse
Efstathia Chioteli, Ioannis Batas, Diomidis Spinellis
Context: Software development projects increasingly adopt unit testing as a way to identify and correct program faults early in the construction process. Code that is unit tested s…