Antonios Lalas

Dr. Antonios Lalas


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 November 2019 in Sensors
Verified
Journal Article
Open access
PDF file
SSStamatios Samaras
Stamatios Samaras
EDEleni Diamantidou
Eleni Diamantidou
DADimitrios Ataloglou
Dimitrios Ataloglou
NSNikos Sakellariou
Nikos Sakellariou
AVAnastasios Vafeiadis
Anastasios Vafeiadis
DTDimitrios Tzovaras
Dimitrios Tzovaras
Usage of Unmanned Aerial Vehicles (UAVs) is growing rapidly in a wide range of consumer applications, as they prove to be both autonomous and flexible in a variety of environments and tasks. However, this versatility and ease of use also brings a rapid evolution of threats by malicious actors that can use UAVs for criminal activities, converting them to passive or active threats. The need to protect critical infrastructures and important events from such threats has brought advances in counter UAV (c-UAV) applications. Nowadays, c-UAV applications offer systems that comprise a multi-sensory arsenal often including electro-optical, thermal, acoustic, radar and radio frequency sensors, whose information can be fused to increase the confidence of threat’s identification. Nevertheless, real-time surveillance is a cumbersome process, but it is absolutely essential to detect promptly the occurrence of adverse events or conditions. To that end, many challenging tasks arise such as object detection, classification, multi-object tracking and multi-sensor information fusion. In recent years, researchers have utilized deep learning based methodologies to tackle these tasks for generic objects and made noteworthy progress, yet applying deep learning for UAV detection and classification is considered a novel concept. Therefore, the need to present a complete overview of deep learning technologies applied to c-UAV related tasks on multi-sensor data has emerged. The aim of this paper is to describe deep learning advances on c-UAV related tasks when applied to data originating from many different sensors as well as multi-sensor information fusion. This survey may help in making recommendations and improvements of c-UAV applications for the future.

29 September 2020 in Electronics
Verified
Journal Article
Open access
PDF file
IPIoannis Papadimitriou
Ioannis Papadimitriou
AVAnastasios Vafeiadis
Anastasios Vafeiadis
ALAntonios Lalas
Antonios Lalas
KVKonstantinos Votis
Konstantinos Votis
DTDimitrios Tzovaras
Dimitrios Tzovaras
Audio-based event detection poses a number of different challenges that are not encountered in other fields, such as image detection. Challenges such as ambient noise, low Signal-to-Noise Ratio (SNR) and microphone distance are not yet fully understood. If the multimodal approaches are to become better in a range of fields of interest, audio analysis will have to play an integral part. Event recognition in autonomous vehicles (AVs) is such a field at a nascent stage that can especially leverage solely on audio or can be part of the multimodal approach. In this manuscript, an extensive analysis focused on the comparison of different magnitude representations of the raw audio is presented. The data on which the analysis is carried out is part of the publicly available MIVIA Audio Events dataset. Single channel Short-Time Fourier Transform (STFT), mel-scale and Mel-Frequency Cepstral Coefficients (MFCCs) spectrogram representations are used. Furthermore, aggregation methods of the aforementioned spectrogram representations are examined; the feature concatenation compared to the stacking of features as separate channels. The effect of the SNR on recognition accuracy and the generalization of the proposed methods on datasets that were both seen and not seen during training are studied and reported.

1 September 2020 in Sensors
Verified
Journal Article
Open access
PDF file
Dimitris TsiktsirisDimitris Tsiktsiris
Dimitris Tsiktsiris
NDNikolaos Dimitriou
Nikolaos Dimitriou
ALAntonios Lalas
Antonios Lalas
Minas DasygenisMinas Dasygenis
Minas Dasygenis
KVKonstantinos Votis
Konstantinos Votis
DTDimitrios Tzovaras
Dimitrios Tzovaras
Autonomous vehicles (AVs) are already operating on the streets of many countries around the globe. Contemporary concerns about AVs do not relate to the implementation of fundamental technologies, as they are already in use, but are rather increasingly centered on the way that such technologies will affect emerging transportation systems, our social environment, and the people living inside it. Many concerns also focus on whether such systems should be fully automated or still be partially controlled by humans. This work aims to address the new reality that is formed in autonomous shuttles mobility infrastructures as a result of the absence of the bus driver and the increased threat from terrorism in European cities. Typically, drivers are trained to handle incidents of passengers’ abnormal behavior, incidents of petty crimes, and other abnormal events, according to standard procedures adopted by the transport operator. Surveillance using camera sensors as well as smart software in the bus will maximize the feeling and the actual level of security. In this paper, an online, end-to-end solution is introduced based on deep learning techniques for the timely, accurate, robust, and automatic detection of various petty crime types. The proposed system can identify abnormal passenger behavior such as vandalism and accidents but can also enhance passenger security via petty crimes detection such as aggression, bag-snatching, and vandalism. The solution achieves excellent results across different use cases and environmental conditions.

31 August 2022 in Applied Sciences
Verified
Journal Article
Open access
PDF file
ILIvan Lazic
Ivan Lazic
FAFerran Agullo
Ferran Agullo
SASusanna Ausso
Susanna Ausso
BSBruno Alves dos Santos
Bruno Alves dos Santos
CBCaroline Barelle
Caroline Barelle
ACAndreas Charalambous
Andreas Charalambous
Finding new ways to cost-effectively facilitate population screening and improve cancer diagnoses at an early stage supported by data-driven AI models provides unprecedented opportunities to reduce cancer related mortality. This work presents the INCISIVE project initiative towards enhancing AI solutions for health imaging by unifying, harmonizing, and securely sharing scattered cancer-related data to ensure large datasets which are critically needed to develop and evaluate trustworthy AI models. The adopted solutions of the INCISIVE project have been outlined in terms of data collection, harmonization, data sharing, and federated data storage in compliance with legal, ethical, and FAIR principles. Experiences and examples feature breast cancer data integration and mammography collection, indicating the current progress, challenges, and future directions.

14 June 2023
Verified
Conference Paper
Open access
GAGeorgios Agrafiotis
Georgios Agrafiotis
EMEftychia Makri
Eftychia Makri
ALAntonios Lalas
Antonios Lalas
KVKonstantinos Votis
Konstantinos Votis
DTDimitrios Tzovaras
Dimitrios Tzovaras
NTNikolaos Tsampieris
Nikolaos Tsampieris
As 5G networks become more complex, cyber attacks targeting IoT devices are deemed a serious concern. This work proposes a novel approach to detect 5G malware traffic using a network packet preprocess toolkit and machine learning models. The system can transform packets into images or embeddings, which allows for more accurate representations that can be applied in a commercial Intrusion Detection System application in a protocol agnostic manner. The paper introduces Long Short-Term Memory Autoencoders as the preprocessing method for embeddings generation followed by a Fully-Connected network for classification purposes of a 5G-dedicated dataset. The proposed approach is efficient and adaptable to evolving threats and protocols, achieving enhanced accuracy rates in detecting 5G malware traffic. This new method can facilitate defending against 5G malware attacks and paves the way for future developments in 6G networks.

29 August 2024 in Energies
Verified
Journal Article
Open access
PDF file
SPSofia Polymeni
Sofia Polymeni
VPVasileios Pitsiavas
Vasileios Pitsiavas
Georgios SpanosGeorgios Spanos
Georgios Spanos
QMQuentin Matthewson
Quentin Matthewson
ALAntonios Lalas
Antonios Lalas
DTDimitrios Tzovaras
Dimitrios Tzovaras
With the global transportation sector being a major contributor to greenhouse gas (GHG) emissions, transitioning to cleaner and more efficient forms of transportation is essential for mitigating climate change and improving air quality. Toward sustainable mobility, Fuel Cell Electric Vehicles (FCEVs) have emerged as a promising solution offering zero-emission transportation without sacrificing performance or range. However, FCEV adoption still faces significant challenges regarding refueling infrastructure. This work proposes an innovative refueling automation service for FCEVs to facilitate the refueling procedure and to increase the fuel cell lifetime, by leveraging (i) Big Data, namely, real-time mobility data and (ii) Machine Learning (ML) for the energy consumption forecasting to dynamically adjust refueling priorities. The proposed service was evaluated on a simulated FCEV energy consumption dataset, generated using both the Future Automotive Systems Technology Simulator and real-time data, including traffic information and details from a real-world on demand Public Transportation service in the Geneva Canton region. The experimental results showcased that all three ML algorithms achieved high accuracy in forecasting the vehicle’s energy consumption with very low errors on the order of 10% and below 20% for the normalized Mean Absolute Error and normalized Root Mean Squared Error metrics, respectively, indicating the high potential of the suggested service.