Sotirios Chatzis

According to our database, Sotirios Chatzis authored at least 108 papers between 2006 and 2023.

Collaborative distances:

• Dijkstra number of four.
• Erdős number of four.

2023

Continuous authentication with feature-level fusion of touch gestures and keystroke dynamics to solve security and usability issues.

Ioannis Stylios, Sotirios Chatzis, Olga Thanou, Spyros Kokolakis

Comput. Secur., September, 2023

DISCOVER: Making Vision Networks Interpretable via Competition and Dissection.

Konstantinos P. Panousis, Sotirios Chatzis

Proceedings of the Advances in Neural Information Processing Systems 36: Annual Conference on Neural Information Processing Systems 2023, 2023

A New Dataset for End-to-End Sign Language Translation: The Greek Elementary School Dataset.

Andreas Voskou, Konstantinos P. Panousis, Harris Partaourides, Kyriakos Tolias, Sotirios Chatzis

Proceedings of the IEEE/CVF International Conference on Computer Vision, 2023

2022

Rethinking Bayesian Learning for Data Analysis: The art of prior and inference in sparsity-aware modeling.

Lei Cheng, Feng Yin, Sergios Theodoridis, Sotirios Chatzis, Tsung-Hui Chang

IEEE Signal Process. Mag., 2022

Key factors driving the adoption of behavioral biometrics and continuous authentication technology: an empirical research.

Ioannis Stylios, Spyros Kokolakis, Olga Thanou, Sotirios Chatzis

Inf. Comput. Secur., 2022

BioGames: a new paradigm and a behavioral biometrics collection tool for research purposes.

Ioannis Stylios, Spyros Kokolakis, Andreas Skalkos, Sotirios Chatzis

Inf. Comput. Secur., 2022

Stochastic Deep Networks with Linear Competing Units for Model-Agnostic Meta-Learning.

Konstantinos Kalais, Sotirios Chatzis

Proceedings of the International Conference on Machine Learning, 2022

A Deep Learning Approach for Dynamic Balance Sheet Stress Testing.

Anastasios Petropoulos, Vasilis Siakoulis, Konstantinos P. Panousis, Loukas Papadoulas, Sotirios Chatzis

Proceedings of the 3rd ACM International Conference on AI in Finance, 2022

Competing Mutual Information Constraints with Stochastic Competition-Based Activations for Learning Diversified Representations.

Konstantinos P. Panousis, Anastasios Antoniadis, Sotirios Chatzis

Proceedings of the Thirty-Sixth AAAI Conference on Artificial Intelligence, 2022

2021

Re-constructing the interbank links using machine learning techniques. An application to the Greek interbank market.

Anastasios Petropoulos, Vasilis Siakoulis, Panagiotis Lazaris, Sotirios Chatzis

Intell. Syst. Appl., 2021

Behavioral biometrics & continuous user authentication on mobile devices: A survey.

Ioannis Stylios, Spyros Kokolakis, Olga Thanou, Sotirios Chatzis

Inf. Fusion, 2021

Stochastic Local Winner-Takes-All Networks Enable Profound Adversarial Robustness.

Konstantinos P. Panousis, Sotirios Chatzis, Sergios Theodoridis

CoRR, 2021

Dialog Speech Sentiment Classification for Imbalanced Datasets.

Sergis Nicolaou, Lambros Mavrides, Georgina Tryfou, Kyriakos Tolias, Konstantinos P. Panousis, Sotirios Chatzis, Sergios Theodoridis

Proceedings of the Speech and Computer - 23rd International Conference, 2021

Stochastic Transformer Networks with Linear Competing Units: Application to end-to-end SL Translation.

Andreas Voskou, Konstantinos P. Panousis, Dimitrios I. Kosmopoulos, Dimitris N. Metaxas, Sotirios Chatzis

Proceedings of the 2021 IEEE/CVF International Conference on Computer Vision, 2021

Local Competition and Stochasticity for Adversarial Robustness in Deep Learning.

Konstantinos P. Panousis, Sotirios Chatzis, Antonios Alexos, Sergios Theodoridis

Proceedings of the 24th International Conference on Artificial Intelligence and Statistics, 2021

2020

Gated Mixture Variational Autoencoders for Value Added Tax audit case selection.

Christos Kleanthous, Sotirios Chatzis

Knowl. Based Syst., 2020

Local Competition and Uncertainty for Adversarial Robustness in Deep Learning.

Antonios Alexos, Konstantinos P. Panousis, Sotirios Chatzis

CoRR, 2020

Variational Conditional-Dependence Hidden Markov Models for Human Action Recognition.

Konstantinos P. Panousis, Sotirios Chatzis, Sergios Theodoridis

CoRR, 2020

Variational Bayesian Sequence-to-Sequence Networks for Memory-Efficient Sign Language Translation.

Harris Partaourides, Andreas Voskou, Dimitrios I. Kosmopoulos, Sotirios Chatzis, Dimitris N. Metaxas

Proceedings of the Advances in Visual Computing - 15th International Symposium, 2020

A Self-Attentive Emotion Recognition Network.

Harris Partaourides, Kostantinos Papadamou, Nicolas Kourtellis, Ilias Leontiadis, Sotirios Chatzis

Proceedings of the 2020 IEEE International Conference on Acoustics, 2020

Power-law mixtures of bayesian forests for value added tax audit case selection.

Christos Kleanthous, Theodoros Christophides, Sotirios Chatzis

Proceedings of the ICAIF '20: The First ACM International Conference on AI in Finance, 2020

2019

t-Exponential Memory Networks for Question-Answering Machines.

Kyriakos Tolias, Sotirios P. Chatzis

IEEE Trans. Neural Networks Learn. Syst., 2019

Nonparametric Bayesian Deep Networks with Local Competition.

Konstantinos P. Panousis, Sotirios Chatzis, Sergios Theodoridis

Proceedings of the 36th International Conference on Machine Learning, 2019

2018

Leveraging Statistical Machine Learning to Address Failure Localization in Optical Networks.

Tania Panayiotou, Sotirios P. Chatzis, Georgios Ellinas

JOCN, 2018

Latent subspace modeling of sequential data under the maximum entropy discrimination framework.

Sotirios P. Chatzis

Neurocomputing, 2018

Deep learning with <i>t</i>-exponential Bayesian kitchen sinks.

Harris Partaourides, Sotirios Chatzis

Expert Syst. Appl., 2018

Forecasting stock market crisis events using deep and statistical machine learning techniques.

Sotirios P. Chatzis, Vasilis Siakoulis, Anastasios Petropoulos, Evangelos Stavroulakis, Nikos E. Vlachogiannakis

Expert Syst. Appl., 2018

Quantum Statistics-Inspired Neural Attention.

Aristotelis Charalampous, Sotirios Chatzis

CoRR, 2018

Amortized Context Vector Inference for Sequence-to-Sequence Networks.

Sotirios Chatzis, Aristotelis Charalampous, Kyriacos Tolias, Sotiris A. Vassou

CoRR, 2018

Deep learning with t-exponential Bayesian kitchen sinks.

Harris Partaourides, Sotirios Chatzis

CoRR, 2018

The Good, the Bad and the Bait: Detecting and Characterizing Clickbait on YouTube.

Savvas Zannettou, Sotirios Chatzis, Kostantinos Papadamou, Michael Sirivianos

Proceedings of the 2018 IEEE Security and Privacy Workshops, 2018

On learning bandwidth allocation models for time-varying traffic in flexible optical networks.

Tania Panayiotou, Konstantinos Manousakis, Sotirios P. Chatzis, Georgios Ellinas

Proceedings of the 2018 International Conference on Optical Network Design and Modeling, 2018

Charging Policies for PREYs used for Service Delivery: A Reinforcement Learning Approach.

Tania Panayiotou, Sotirios P. Chatzis, Christos G. Panayiotou, Georgios Ellinas

Proceedings of the 21st International Conference on Intelligent Transportation Systems, 2018

A Recurrent Latent Variable Model for Supervised Modeling of High-Dimensional Sequential Data.

Panayiotis Christodoulou, Sotirios P. Chatzis, Andreas S. Andreou

Proceedings of the 2018 Innovations in Intelligent Systems and Applications, 2018

Indian Buffet Process Deep Generative Models for Semi-Supervised Classification.

Sotirios P. Chatzis

Proceedings of the 2018 IEEE International Conference on Acoustics, 2018

2017

Performance Analysis of a Data-Driven Quality-of-Transmission Decision Approach on a Dynamic Multicast-Capable Metro Optical Network.

Tania Panayiotou, Sotirios P. Chatzis, Georgios Ellinas

JOCN, 2017

A hidden Markov model with dependence jumps for predictive modeling of multidimensional time-series.

Anastasios Petropoulos, Sotirios P. Chatzis, Stelios Xanthopoulos

Inf. Sci., 2017

Asymmetric deep generative models.

Harris Partaourides, Sotirios P. Chatzis

Neurocomputing, 2017

A stacked generalization system for automated FOREX portfolio trading.

Anastasios Petropoulos, Sotirios P. Chatzis, Vasilis Siakoulis, Nikos E. Vlachogiannakis

Expert Syst. Appl., 2017

Recurrent Latent Variable Networks for Session-Based Recommendation.

Sotirios P. Chatzis, Panayiotis Christodoulou, Andreas S. Andreou

Proceedings of the 2nd Workshop on Deep Learning for Recommender Systems, 2017

Deep Network Regularization via Bayesian Inference of Synaptic Connectivity.

Harris Partaourides, Sotirios P. Chatzis

Proceedings of the Advances in Knowledge Discovery and Data Mining, 2017

Deep Bayesian Matrix Factorization.

Sotirios P. Chatzis

Proceedings of the Advances in Knowledge Discovery and Data Mining, 2017

A probabilistic approach for failure localization.

Tania Panayiotou, Sotirios P. Chatzis, Georgios Ellinas

Proceedings of the 2017 International Conference on Optical Network Design and Modeling, 2017

A Variational Recurrent Neural Network for Session-Based Recommendations using Bayesian Personalized Ranking.

Panayiotis Christodoulou, Sotirios P. Chatzis, Andreas S. Andreou

Proceedings of the Information Systems Development: Advances in Methods, Tools and Management, 2017

Recurrent latent variable conditional heteroscedasticity.

Sotirios P. Chatzis

Proceedings of the 2017 IEEE International Conference on Acoustics, 2017

2016

Software defect prediction using doubly stochastic Poisson processes driven by stochastic belief networks.

Andreas S. Andreou, Sotirios P. Chatzis

J. Syst. Softw., 2016

Maximum entropy discrimination factor analyzers.

Sotirios P. Chatzis

Neurocomputing, 2016

A Nonstationary Hidden Markov Model with Approximately Infinitely-Long Time-Dependencies.

Sotirios Chatzis, Dimitrios I. Kosmopoulos, George Papadourakis

Int. J. Artif. Intell. Tools, 2016

A novel corporate credit rating system based on Student's-t hidden Markov models.

Anastasios Petropoulos, Sotirios P. Chatzis, Stylianos Z. Xanthopoulos

Expert Syst. Appl., 2016

A data-driven QoT decision approach for multicast connections in metro optical networks.

Tania Panayiotou, Georgios Ellinas, Sotirios P. Chatzis

Proceedings of the 2016 International Conference on Optical Network Design and Modeling, 2016

Users' Attitudes on Mobile Devices: Can Users' Practices Protect their Sensitive Data?

Ioannis Stylios, Spyros Kokolakis, Olga Thanou, Sotirios Chatzis

Proceedings of the 10th Mediterranean Conference on Information Systems, 2016

2015

A Latent Manifold Markovian Dynamics Gaussian Process.

Sotirios P. Chatzis, Dimitrios I. Kosmopoulos

IEEE Trans. Neural Networks Learn. Syst., 2015

Maximum Entropy Discrimination Poisson Regression for Software Reliability Modeling.

Sotirios P. Chatzis, Andreas S. Andreou

IEEE Trans. Neural Networks Learn. Syst., 2015

Sparse Bayesian Recurrent Neural Networks.

Sotirios P. Chatzis

Proceedings of the Machine Learning and Knowledge Discovery in Databases, 2015

A Nonparametric Bayesian Approach toward Stacked Convolutional Independent Component Analysis.

Sotirios P. Chatzis, Dimitrios I. Kosmopoulos

Proceedings of the 2015 IEEE International Conference on Computer Vision, 2015

Inducing Space Dirichlet Process Mixture Large-Margin Entity RelationshipInference in Knowledge Bases.

Sotirios P. Chatzis

Proceedings of the 24th ACM International Conference on Information and Knowledge Management, 2015

2014

Gaussian Process-Mixture Conditional Heteroscedasticity.

Emmanouil A. Platanios, Sotirios P. Chatzis

IEEE Trans. Pattern Anal. Mach. Intell., 2014

A Nonparametric Bayesian Approach Toward Stacked Convolutional Independent Component Analysis.

Sotirios P. Chatzis

CoRR, 2014

Maximum Entropy Discrimination Denoising Autoencoders.

Sotirios P. Chatzis

CoRR, 2014

Developing Public Transport Network systems: The DIANA approach.

Dimitrios I. Kosmopoulos, M. Kalohristianakis, Athanasios G. Malamos, Sotirios Chatzis, M. Pternea, Konstantinos L. Kepaptsoglou, Matthew G. Karlaftis

Proceedings of the 18th Panhellenic Conference on Informatics, 2014

A Partially-Observable Markov Decision Process for Dealing with Dynamically Changing Environments.

Sotirios P. Chatzis, Dimitrios I. Kosmopoulos

Proceedings of the Artificial Intelligence Applications and Innovations, 2014

A Non-stationary Infinite Partially-Observable Markov Decision Process.

Sotirios P. Chatzis, Dimitrios I. Kosmopoulos

Proceedings of the Artificial Neural Networks and Machine Learning - ICANN 2014, 2014

Echo-State Conditional Restricted Boltzmann Machines.

Sotirios Chatzis

Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence, 2014

Dynamic Bayesian Probabilistic Matrix Factorization.

Sotirios Chatzis

Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence, 2014

2013

A conditional random field-based model for joint sequence segmentation and classification.

Sotirios P. Chatzis, Dimitrios I. Kosmopoulos, Paul Doliotis

Pattern Recognit., 2013

A Markov random field-regulated Pitman-Yor process prior for spatially constrained data clustering.

Sotirios P. Chatzis

Pattern Recognit., 2013

The Infinite-Order Conditional Random Field Model for Sequential Data Modeling.

Sotirios P. Chatzis, Yiannis Demiris

IEEE Trans. Pattern Anal. Mach. Intell., 2013

A latent variable Gaussian process model with Pitman-Yor process priors for multiclass classification.

Sotirios P. Chatzis

Neurocomputing, 2013

Corrigendum to "Maximum-margin classification of sequential data with infinitely-long temporal dependencies" [Expert Systems with Applications 40 (11) (2013) 4519-4527].

Sotirios P. Chatzis

Expert Syst. Appl., 2013

Margin-maximizing classification of sequential data with infinitely-long temporal dependencies.

Sotirios P. Chatzis

Expert Syst. Appl., 2013

Infinite Markov-Switching Maximum Entropy Discrimination Machines.

Sotirios Chatzis

Proceedings of the 30th International Conference on Machine Learning, 2013

Nonparametric bayesian multitask collaborative filtering.

Sotirios Chatzis

Proceedings of the 22nd ACM International Conference on Information and Knowledge Management, 2013

2012

A Quantum-Statistical Approach Toward Robot Learning by Demonstration.

Sotirios P. Chatzis, Dimitrios Korkinof, Yiannis Demiris

IEEE Trans. Robotics, 2012

Nonparametric Mixtures of Gaussian Processes With Power-Law Behavior.

Sotirios P. Chatzis, Yiannis Demiris

IEEE Trans. Neural Networks Learn. Syst., 2012

Visual Workflow Recognition Using a Variational Bayesian Treatment of Multistream Fused Hidden Markov Models.

Sotirios P. Chatzis, Dimitrios I. Kosmopoulos

IEEE Trans. Circuits Syst. Video Technol., 2012

A nonparametric Bayesian approach toward robot learning by demonstration.

Sotirios P. Chatzis, Dimitrios Korkinof, Yiannis Demiris

Robotics Auton. Syst., 2012

A possibilistic clustering approach toward generative mixture models.

Sotirios P. Chatzis, Gavrill Tsechpenakis

Pattern Recognit., 2012

A reservoir-driven non-stationary hidden Markov model.

Sotirios P. Chatzis, Yiannis Demiris

Pattern Recognit., 2012

The copula echo state network.

Sotirios P. Chatzis, Yiannis Demiris

Pattern Recognit., 2012

A Coupled Indian Buffet Process Model for Collaborative Filtering.

Sotirios P. Chatzis

Proceedings of the 4th Asian Conference on Machine Learning, 2012

A spatially-constrained normalized Gamma process prior.

Sotirios P. Chatzis, Dimitrios Korkinof, Yiannis Demiris

Expert Syst. Appl., 2012

The echo state conditional random field model for sequential data modeling.

Sotirios P. Chatzis, Yiannis Demiris

Expert Syst. Appl., 2012

A sparse nonparametric hierarchical Bayesian approach towards inductive transfer for preference modeling.

Sotirios P. Chatzis, Yiannis Demiris

Expert Syst. Appl., 2012

A Mixture Gaussian Process Conditional Heteroscedasticity Model with Power-Law Nature

Emmanouil A. Platanios, Sotirios P. Chatzis

CoRR, 2012

The Kernel Pitman-Yor Process

Sotirios P. Chatzis, Dimitrios Korkinof, Yiannis Demiris

CoRR, 2012

A Spatially-Constrained Normalized Gamma Process for Data Clustering.

Sotirios P. Chatzis, Dimitrios Korkinof, Yiannis Demiris

Proceedings of the Artificial Intelligence Applications and Innovations, 2012

2011

Echo State Gaussian Process.

Sotirios P. Chatzis, Yiannis Demiris

IEEE Trans. Neural Networks, 2011

A variational Bayesian methodology for hidden Markov models utilizing Student's-t mixtures.

Sotirios Chatzis, Dimitrios I. Kosmopoulos

Pattern Recognit., 2011

Numerical optimization using synergetic swarms of foraging bacterial populations.

Sotirios P. Chatzis, Spyros Koukas

Expert Syst. Appl., 2011

A fuzzy c-means-type algorithm for clustering of data with mixed numeric and categorical attributes employing a probabilistic dissimilarity functional.

Sotirios P. Chatzis

Expert Syst. Appl., 2011

Deformable probability maps: Probabilistic shape and appearance-based object segmentation.

Gavrill Tsechpenakis, Sotirios P. Chatzis

Comput. Vis. Image Underst., 2011

The One-Hidden Layer Non-parametric Bayesian Kernel Machine.

Sotirios P. Chatzis, Dimitrios Korkinof, Yiannis Demiris

Proceedings of the IEEE 23rd International Conference on Tools with Artificial Intelligence, 2011

2010

The infinite hidden Markov random field model.

Sotirios P. Chatzis, Gabriel Tsechpenakis

IEEE Trans. Neural Networks, 2010

Robust Visual Behavior Recognition.

Dimitrios I. Kosmopoulos, Sotirios P. Chatzis

IEEE Signal Process. Mag., 2010

Hidden Markov Models with Nonelliptically Contoured State Densities.

Sotirios P. Chatzis

IEEE Trans. Pattern Anal. Mach. Intell., 2010

A method for training finite mixture models under a fuzzy clustering principle.

Sotirios Chatzis

Fuzzy Sets Syst., 2010

Which brainstem cells generate the respiration cycles?

Allison W. Irvine, Sotirios P. Chatzis, Gavrill Tsechpenakis

Proceedings of the 2010 IEEE International Symposium on Biomedical Imaging: From Nano to Macro, 2010

2009

Factor Analysis Latent Subspace Modeling and Robust Fuzzy Clustering Using t -Distributions.

Sotirios Chatzis, Theodora A. Varvarigou

IEEE Trans. Fuzzy Syst., 2009

Vision-based production of personalized video.

Dimitrios I. Kosmopoulos, Anastasios D. Doulamis, Alexandros Makris, Nikolaos D. Doulamis, Sotirios Chatzis, Stuart E. Middleton

Signal Process. Image Commun., 2009

Robust Sequential Data Modeling Using an Outlier Tolerant Hidden Markov Model.

Sotirios Chatzis, Dimitrios I. Kosmopoulos, Theodora A. Varvarigou

IEEE Trans. Pattern Anal. Mach. Intell., 2009

2008

Signal Modeling and Classification Using a Robust Latent Space Model Based on t Distributions.

Sotirios Chatzis, Dimitrios I. Kosmopoulos, Theodora A. Varvarigou

IEEE Trans. Signal Process., 2008

A Fuzzy Clustering Approach Toward Hidden Markov Random Field Models for Enhanced Spatially Constrained Image Segmentation.

Sotirios Chatzis, Theodora A. Varvarigou

IEEE Trans. Fuzzy Syst., 2008

Robust fuzzy clustering using mixtures of Student's-t distributions.

Sotirios Chatzis, Theodora A. Varvarigou

Pattern Recognit. Lett., 2008

Managing service level agreement contracts in OGSA-based Grids.

Antonios Litke, Kleopatra Konstanteli, Vassiliki Andronikou, Sotirios Chatzis, Theodora A. Varvarigou

Future Gener. Comput. Syst., 2008

A robust approach towards sequential data modeling and its application in automatic gesture recognition.

Sotirios Chatzis, Dimitrios I. Kosmopoulos, Theodora A. Varvarigou

Proceedings of the IEEE International Conference on Acoustics, 2008

2007

A content-based image retrieval scheme allowing for robust automatic personalization.

Sotirios Chatzis, Anastasios D. Doulamis, Theodora A. Varvarigou

Proceedings of the 6th ACM International Conference on Image and Video Retrieval, 2007

2006

Video Representation and Retrieval Using Spatio-temporal Descriptors and Region Relations.

Sotirios Chatzis, Anastasios D. Doulamis, Dimitrios I. Kosmopoulos, Theodora A. Varvarigou

Proceedings of the Artificial Neural Networks, 2006

A Cross Media Platform for Personalized Leisure & Entertainment: The POLYMNIA Approach.

Vasilios Anagnostopoulos, Sotirios Chatzis, Constantinos Lalos, Anastasios D. Doulamis, Dimitrios I. Kosmopoulos, Theodora A. Varvarigou, Helmut Neuschmied, Georg Thallinger, Stuart E. Middleton, Matthew Addis, Eduardo Bustos, Fabrizio Giorgini

Proceedings of the Second International Conference on Automated Production of Cross Media Content for Multi-Channel Distribution, 2006