Theofanis Kalampokas

Dr. Theofanis Kalampokas

MLV Research Group, Department of Informatics, Democritus University of Thrace, Kavála, Anatolikí Makedonía kai Thráki, Greece
orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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10 September 2021 in Agronomy
Verified
Journal Article
Open access
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Chris LytridisChris Lytridis
Chris Lytridis
Vassilis KaburlasosVassilis Kaburlasos
Vassilis Kaburlasos
THEODORE PACHIDISTHEODORE PACHIDIS
THEODORE PACHIDIS
MMMichalis Manios
Michalis Manios
Eleni VrochidouEleni Vrochidou
Eleni Vrochidou
SCStamatis Chatzistamatis
Stamatis Chatzistamatis
Agricultural robotics has been a popular subject in recent years from an academic as well as a commercial point of view. This is because agricultural robotics addresses critical issues such as seasonal shortages in manual labor, e.g., during harvest, as well as the increasing concern regarding environmentally friendly practices. On one hand, several individual agricultural robots have already been developed for specific tasks (e.g., for monitoring, spraying, harvesting, transport, etc.) with varying degrees of effectiveness. On the other hand, the use of cooperative teams of agricultural robots in farming tasks is not as widespread; yet, it is an emerging trend. This paper presents a comprehensive overview of the work carried out so far in the area of cooperative agricultural robotics and identifies the state-of-the-art. This paper also outlines challenges to be addressed in fully automating agricultural production; the latter is promising for sustaining an increasingly vast human population, especially in cases of pandemics such as the recent COVID-19 pandemic.

24 May 2023 in Electronics
Verified
Journal Article
Open access
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Kyriaki A TycholaKyriaki A Tychola
Kyriaki A Tychola
TKTheofanis Kalampokas
Theofanis Kalampokas
George A. PapakostasGeorge A. Papakostas
George A. Papakostas
Quantum computing has been proven to excel in factorization issues and unordered search problems due to its capability of quantum parallelism. This unique feature allows exponential speed-up in solving certain problems. However, this advantage does not apply universally, and challenges arise when combining classical and quantum computing to achieve acceleration in computation speed. This paper aims to address these challenges by exploring the current state of quantum machine learning and benchmarking the performance of quantum and classical algorithms in terms of accuracy. Specifically, we conducted experiments with three datasets for binary classification, implementing Support Vector Machine (SVM) and Quantum SVM (QSVM) algorithms. Our findings suggest that the QSVM algorithm outperforms classical SVM on complex datasets, and the performance gap between quantum and classical models increases with dataset complexity, as simple models tend to overfit with complex datasets. While there is still a long way to go in terms of developing quantum hardware with sufficient resources, quantum machine learning holds great potential in areas such as unsupervised learning and generative models. Moving forward, more efforts are needed to explore new quantum learning models that can leverage the power of quantum mechanics to overcome the limitations of classical machine learning.

29 April 2021 in Electronics
Verified
Journal Article
Open access
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Eleni VrochidouEleni Vrochidou
Eleni Vrochidou
KTKonstantinos Tziridis
Konstantinos Tziridis
ANAlexander Nikolaou
Alexander Nikolaou
TKTheofanis Kalampokas
Theofanis Kalampokas
George A. PapakostasGeorge A. Papakostas
George A. Papakostas
Vassilis KaburlasosVassilis Kaburlasos
Vassilis Kaburlasos
This work pursues the potential of extending “Industry 4.0” practices to farming toward achieving “Agriculture 4.0”. Our interest is in fruit harvesting, motivated by the problem of addressing the shortage of seasonal labor. In particular, here we present an integrated system architecture of an Autonomous Robot for Grape harvesting (ARG). The overall system consists of three interdependent units: (1) an aerial unit, (2) a remote-control unit and (3) the ARG ground unit. Special attention is paid to the ARG; the latter is designed and built to carry out three viticultural operations, namely harvest, green harvest and defoliation. We present an overview of the multi-purpose overall system, the specific design of each unit of the system and the integration of all subsystems. In addition, the fully sensory-based sensing system architecture and the underlying vision system are analyzed. Due to its modular design, the proposed system can be extended to a variety of different crops and/or orchards.

3 February 2025 in Diagnostics
Verified
Journal Article
Open access
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PGPanagiotis Georgiadis
Panagiotis Georgiadis
EGEmmanouil Gkouvrikos
Emmanouil Gkouvrikos
Eleni VrochidouEleni Vrochidou
Eleni Vrochidou
TKTheofanis Kalampokas
Theofanis Kalampokas
George A. PapakostasGeorge A. Papakostas
George A. Papakostas
Background/Objectives: This work brings to light the importance of forming large training datasets with diverse images generated and proposes an image dataset merging application, namely, the Data Merger App, to streamline the management and synthesis of large-scale datasets. The Data Merger can recognize common classes across various datasets and provides tools to combine and organize them in a well-structured and easily accessible way. Methods: A case study is then presented, leveraging four different Convolutional Neural Network (CNN) models, VGG16, ResNet50, MobileNetV3-small, and DenseNet-161, and a Visual Transformer (ViT), to benchmark their performance to classify skin cancer images, when trained on single datasets and on enhanced hyperdatasets generated by the Data Merger App. Results: Extended experimental results indicated that enhanced hyperdatasets are efficient and able to improve the accuracies of classification models, whether the models are trained from scratch or by using Transfer Learning. Moreover, the ViT model was reported for higher classification accuracies compared to CNNs on datasets with a limited number of classes, reporting 91.87% accuracy for 9 classes, as well as in the case of enhanced hyperdatasets with multiple numbers of classes, reporting accuracy of 58% for 32 classes. Conclusions: In essence, this work demonstrates the great significance of data combination, as well as the utility value of the developed prototype web application as a critical tool for researchers and data scientists, enabling them to easily handle complex datasets, combine datasets into larger diverse versions, to further enhance the generalization ability of models and improve the quality and impact of their work.

28 November 2023 in Axioms
Verified
Journal Article
Open access
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Eleni VrochidouEleni Vrochidou
Eleni Vrochidou
Vladan PapićVladan Papić
Vladan Papić
TKTheofanis Kalampokas
Theofanis Kalampokas
George A. PapakostasGeorge A. Papakostas
George A. Papakostas
Automated solutions for medical diagnosis based on computer vision form an emerging field of science aiming to enhance diagnosis and early disease detection. The detection and quantification of facial asymmetries enable facial palsy evaluation. In this work, a detailed review of the quantification of facial palsy takes place, covering all methods ranging from traditional manual mathematical modeling to automated computer vision-based methods. Moreover, facial palsy quantification is defined in terms of facial asymmetry indices calculation for different image modalities. The aim is to introduce readers to the concept of mathematical modeling approaches for facial palsy detection and evaluation and present the process of the development of this separate application field over time. Facial landmark extraction, facial datasets, and palsy grading systems are included in this research. As a general conclusion, machine learning methods for the evaluation of facial palsy lead to limited performance due to the use of handcrafted features, combined with the scarcity of the available datasets. Deep learning methods allow the automatic learning of discriminative deep facial features, leading to comparatively higher performance accuracies. Datasets limitations, proposed solutions, and future research directions in the field are also presented.

9 May 2023 in IEEE Access
Verified
Journal Article
Open access
TKTheofanis Kalampokas
Theofanis Kalampokas
KTKonstantinos Tziridis
Konstantinos Tziridis
NKNikolaos Kalampokas
Nikolaos Kalampokas
ANAlexandros Nikolaou
Alexandros Nikolaou
Eleni VrochidouEleni Vrochidou
Eleni Vrochidou
George A. PapakostasGeorge A. Papakostas
George A. Papakostas
Globalization of markets involves new strategies and price policies from professionals that contribute to global competitiveness. Airline companies are changing tickets’ prices very often considering a variety of factors based on their proprietary rules and algorithms that are searching for the most suitable price policy. Recently, Artificial Intelligence (AI) models are exploited for the latter task, due to their compactness, fast adaptability, and many potentials in data generalization. This paper represents an analysis of airfare price prediction towards finding similarities in the pricing policies of different Airline companies by using AI Techniques. More specifically, a set of effective features is extracted from 136.917 data flights of Aegean, Turkish, Austrian and Lufthansa Airlines for six popular international destinations. The extracted set of features is then used to conduct a holistic analysis from the perspective of the end user who seeks the most affordable ticket cost, considering a destination-based evaluation including all airlines, and an airline-based evaluation including all destinations. For the latter cause, AI models from three different domains and a total of 16 model architectures are considered to resolve the airfare price prediction problem: Machine Learning (ML) with eight state-of-the-art models, Deep Learning (DL) with six CNN models and Quantum Machine Learning (QML) with two models. Experimental results reveal that at least three models from each domain, ML, DL, and QML, are able to achieve accuracies between 89% and 99% in this regression problem, for different international destinations and airline companies.