no code implementations • 21 Aug 2024 • Manos Kirtas, Konstantinos Tsampazis, Loukia Avramelou, Nikolaos Passalis, Anastasios Tefas
In this paper, we propose a non-negative training approach for actor models in RL, enabling the extraction of part-based representations that enhance interpretability while adhering to non-negative constraints.
no code implementations • 21 Jul 2024 • Konstantinos Gounis, Nikolaos Passalis, Anastasios Tefas
In this study a model pipeline is proposed that combines computer vision with control-theoretic methods and utilizes low cost sensors.
no code implementations • 15 Dec 2023 • Stefanos Ginargiros, Nikolaos Passalis, Anastasios Tefas
Despite the significant potential of active perception, it poses several challenges, primarily involving significant changes in training pipelines for deep learning models.
no code implementations • 2 Oct 2023 • Manos Kirtas, Nikolaos Passalis, Nikolaos Pleros, Anastasios Tefas
To this end, we introduce a methodology to obtain the non-negative isomorphic equivalents of regular neural networks that meet requirements of neuromorphic hardware, overcoming the aforementioned limitations.
no code implementations • 23 Jul 2023 • Paraskevi Nousi, Loukia Avramelou, Georgios Rodinos, Maria Tzelepi, Theodoros Manousis, Konstantinos Tsampazis, Kyriakos Stefanidis, Dimitris Spanos, Manos Kirtas, Pavlos Tosidis, Avraam Tsantekidis, Nikolaos Passalis, Anastasios Tefas
Financial portfolio management describes the task of distributing funds and conducting trading operations on a set of financial assets, such as stocks, index funds, foreign exchange or cryptocurrencies, aiming to maximize the profit while minimizing the loss incurred by said operations.
no code implementations • 14 Jul 2023 • Manos Kirtas, Nikolaos Passalis, Anastasios Tefas
We claim that the proposed framework accelerates training, while leading to more robust models in contrast to traditionally used additive update rule and we experimentally demonstrate their effectiveness in a wide range of task and optimization methods.
no code implementations • 15 Jun 2023 • Maria Tzelepi, Charalampos Symeonidis, Paraskevi Nousi, Efstratios Kakaletsis, Theodoros Manousis, Pavlos Tosidis, Nikos Nikolaidis, Anastasios Tefas
Energy time-series analysis describes the process of analyzing past energy observations and possibly external factors so as to predict the future.
2 code implementations • 12 Feb 2023 • Illia Oleksiienko, Paraskevi Nousi, Nikolaos Passalis, Anastasios Tefas, Alexandros Iosifidis
Uncertainty estimation is an important task for critical problems, such as robotics and autonomous driving, because it allows creating statistically better perception models and signaling the model's certainty in its predictions to the decision method or a human supervisor.
1 code implementation • 27 Sep 2022 • Paraskevi Nousi, Emmanouil Mpampis, Nikolaos Passalis, Ole Green, Anastasios Tefas
In this paper we evaluate the impact of domain shift on human detection models trained on well known object detection datasets when deployed on data outside the distribution of the training set, as well as propose methods to alleviate such phenomena based on the available annotations from the target domain.
1 code implementation • 22 Sep 2022 • Marlin B. Schäfer, Ondřej Zelenka, Alexander H. Nitz, He Wang, Shichao Wu, Zong-Kuan Guo, Zhoujian Cao, Zhixiang Ren, Paraskevi Nousi, Nikolaos Stergioulas, Panagiotis Iosif, Alexandra E. Koloniari, Anastasios Tefas, Nikolaos Passalis, Francesco Salemi, Gabriele Vedovato, Sergey Klimenko, Tanmaya Mishra, Bernd Brügmann, Elena Cuoco, E. A. Huerta, Chris Messenger, Frank Ohme
The final of the 4 provided datasets contained real noise from the O3a observing run and signals up to a duration of 20 seconds with the inclusion of precession effects and higher order modes.
2 code implementations • 6 Jun 2022 • Illia Oleksiienko, Paraskevi Nousi, Nikolaos Passalis, Anastasios Tefas, Alexandros Iosifidis
In this paper, we propose a novel voxel-based 3D single object tracking (3D SOT) method called Voxel Pseudo Image Tracking (VPIT).
1 code implementation • 16 Mar 2022 • Styliani-Christina Fragkouli, Paraskevi Nousi, Nikolaos Passalis, Panagiotis Iosif, Nikolaos Stergioulas, Anastasios Tefas
In several cases, small improvements can be observed, but the most significant improvement still comes from the addition of a second network that models the residual error.
no code implementations • 26 Aug 2021 • Maria Tzelepi, Anastasios Tefas
In this paper, regularized lightweight deep convolutional neural network models, capable of effectively operating in real-time on devices with restricted computational power for high-resolution video input are proposed.
no code implementations • 26 Aug 2021 • Maria Tzelepi, Anastasios Tefas
Knowledge Distillation has been established as a highly promising approach for training compact and faster models by transferring knowledge from heavyweight and powerful models.
no code implementations • 25 Aug 2021 • Maria Tzelepi, Anastasios Tefas
Semantic scene segmentation plays a critical role in a wide range of robotics applications, e. g., autonomous navigation.
no code implementations • 9 Jul 2021 • Paraskevi Nousi, Styliani-Christina Fragkouli, Nikolaos Passalis, Panagiotis Iosif, Theocharis Apostolatos, George Pappas, Nikolaos Stergioulas, Anastasios Tefas
Based on this finding, we design a spiral module with learnable parameters, that is used as the first layer in a neural network, which learns to map the input space to the coefficients.
1 code implementation • 25 May 2020 • Dat Thanh Tran, Nikolaos Passalis, Anastasios Tefas, Moncef Gabbouj, Alexandros Iosifidis
In this paper, we propose 2D-Attention (2DA), a generic attention formulation for sequence data, which acts as a complementary computation block that can detect and focus on relevant sources of information for the given learning objective.
1 code implementation • CVPR 2020 • Nikolaos Passalis, Maria Tzelepi, Anastasios Tefas
The proposed method is capable of overcoming the aforementioned limitations by using an appropriate supervision scheme during the different phases of the training process, as well as by designing and training an appropriate auxiliary teacher model that acts as a proxy model capable of "explaining" the way the teacher works to the student.
1 code implementation • 11 Jun 2019 • Firas Laakom, Nikolaos Passalis, Jenni Raitoharju, Jarno Nikkanen, Anastasios Tefas, Alexandros Iosifidis, Moncef Gabbouj
To further improve the illumination estimation accuracy, we propose a novel attention mechanism for the BoCF model with two variants based on self-attention.
3 code implementations • 21 Feb 2019 • Nikolaos Passalis, Anastasios Tefas, Juho Kanniainen, Moncef Gabbouj, Alexandros Iosifidis
Deep Learning (DL) models can be used to tackle time series analysis tasks with great success.
no code implementations • 24 Jan 2019 • Nikolaos Passalis, Anastasios Tefas, Juho Kanniainen, Moncef Gabbouj, Alexandros Iosifidis
However, combining existing BoF formulations with deep feature extractors pose significant challenges: the distribution of the input features is not stationary, tuning the hyper-parameters of the model can be especially difficult and the normalizations involved in the BoF model can cause significant instabilities during the training process.
no code implementations • 16 Jan 2019 • Nikolaos Passalis, Anastasios Tefas
The proposed method is adapted to the needs of large-scale hashing and information retrieval leading to a novel information-theoretic measure, the Quadratic Spherical Mutual Information (QSMI).
no code implementations • 30 Nov 2018 • Paraskevas Pegios, Nikolaos Passalis, Anastasios Tefas
Universal Neural Style Transfer (NST) methods are capable of performing style transfer of arbitrary styles in a style-agnostic manner via feature transforms in (almost) real-time.
no code implementations • 13 Nov 2018 • Dimitris Spathis, Nikolaos Passalis, Anastasios Tefas
In order to visualize that data in 2D or 3D, usually Dimensionality Reduction (DR) techniques are employed.
1 code implementation • 5 Nov 2018 • Angeliki Papadimitriou, Nikolaos Passalis, Anastasios Tefas
Among the most impressive recent applications of neural decoding is the visual representation decoding, where the category of an object that a subject either sees or imagines is inferred by observing his/her brain activity.
no code implementations • 23 Oct 2018 • Avraam Tsantekidis, Nikolaos Passalis, Anastasios Tefas, Juho Kanniainen, Moncef Gabbouj, Alexandros Iosifidis
The recent surge in Deep Learning (DL) research of the past decade has successfully provided solutions to many difficult problems.
no code implementations • 19 Sep 2018 • Paraskevi Nousi, Avraam Tsantekidis, Nikolaos Passalis, Adamantios Ntakaris, Juho Kanniainen, Anastasios Tefas, Moncef Gabbouj, Alexandros Iosifidis
Forecasting the movements of stock prices is one the most challenging problems in financial markets analysis.
1 code implementation • ECCV 2018 • Nikolaos Passalis, Anastasios Tefas
Knowledge Transfer (KT) techniques tackle the problem of transferring the knowledge from a large and complex neural network into a smaller and faster one.
2 code implementations • ICCV 2017 • Nikolaos Passalis, Anastasios Tefas
Convolutional Neural Networks (CNNs) are well established models capable of achieving state-of-the-art classification accuracy for various computer vision tasks.
1 code implementation • 18 Jun 2017 • Nikolaos Passalis, Anastasios Tefas
The vast majority of Dimensionality Reduction (DR) techniques rely on second-order statistics to define their optimization objective.