Christos Douligeris

University of Piraeus · Department of Informatics

Η πανδημία του COVID-19 προκάλεσε μια απότομη μετάβαση στην ηλεκτρονική μάθηση, αποκαλύπτοντας ελλείψεις και προβλήματα σε υποδομές και διαθέσιμο υλικό, επηρεάζοντας αρνητικά την παιδαγωγική αξιοποίησή της. Η κοινωνική απομόνωση επέβαλε τη χρήση της τηλεκπαίδευσης, αυξάνοντας την ανάγκη αξιοποίησης λογισμικών και διαδικτυακών υποδομών εκτός σχολικώ...

Today, the Vocational Education and Training (VET) curriculum in Greece is state-regulated, combining school-based and work-based learning, and it is offered at upper-secondary and post-secondary levels. There is a need to prepare a new agenda for VET in Greece that follows the rapid technological developments of today. Our paper aims to enrich, re...

The rapid development of technology undoubtedly brings many benefits to education. Flexibility, access, interactivity, and experiential learning open up new possibilities for improving the educational experience. This study highlights the inextricable link between the technological evolution of the internet and education. Each stage of development...

The COVID-19 pandemic has had a huge impact on all educational activities. Within a few weeks, educational systems from primary to higher education had to completely transform their educational approaches and take advantage of e-Learning (eL). However, the sudden conversion to e-learning brought to the fore challenges in the secure use of these sys...

The COVID-19 pandemic has had a huge impact on all educational activities. Within a few weeks, educational systems from primary to higher education had to completely transform their educational approaches and take advantage of e-Learning (eL). However, the sudden conversion to e-learning brought to the fore challenges in the secure use of these sys...

The rapid development of technology undoubtedly brings many benefits to education. Flexibility, access, interactivity, and experiential learning open up new possibilities for improving the educational experience. This study highlights the inextricable link between the technological evolution of the internet and education. Each stage of develo...

Today the Vocational Education and Training curriculum is state-regulated, combining school-based and work-based learning it is offered at upper-secondary and post-secondary levels. The main problem of nowadays period for Vocational Education and Training is about preparing a new agenda for technical education in Greece for the new circumstances. O...

NERO represents a sophisticated Cybersecurity Ecosystem comprising five interconnected frameworks designed to deliver a comprehensive Cybersecurity Awareness initiative. Advocated by ENISA as the optimal method for cultivating a security-centric mindset among employees, NERO integrates activities, resources, and training to nurture a culture of cyb...

As societies are rapidly transforming and technology is evolving and bringing constant change, contemporary trends such as digital technologies and process automation are emerging and evolving. These new trends are changing how we live as well as the wider economy. The scientific questions of this paper focus on the design and modeling of the role...

The primary objective of this paper is to introduce a comprehensive framework designed to automate the assessment of environmental vulnerability status of communication protocols and networked services, within operational contexts. The proposed algorithm leverages the Common Vulnerability Scoring System version 3 (CVSS 3) metrics in conjunction wit...

Wi-Fi networks enable user-friendly network connectivity in various environments, ranging from home to enterprise networks. However, vulnerabilities in Wi-Fi implementations may allow nearby adversaries to gain an initial foothold into a network, e.g., in order to attempt further network penetration. In this paper we propose a methodology for the d...

The widespread adoption of cloud computing has resulted in centralized datacenter structures; however, there is a requirement for smaller-scale distributed infrastructures to meet the demands for speed, responsiveness, and security for critical applications. Single-Board Computers (SBCs) present numerous advantages such as low power consumption, lo...

The organization and utilization of Electronic Data Interchange is part of the methodology of submitting creative proposals for the simplification of administrative practices that can contribute to the effective operation not only of school units but also of public enterprises and organizations in general. This article presents tools for electronic...

Open Educational Resources focuses on the production, licensing, use, and reuse of learning resources and their accessibility from open-access digital repositories as public goods. This drastically reduces the cost of educational materials, making the educational process more flexible, efficient, and accessible for millions of drivers worldwide, es...

In the field of Computer Networks, perhaps more than in any other scientific area, research is developing rapidly as a result of the continuous production of new scientific data and new technologies. In some cases, as in the case of the “Quick UDP Internet Connections” protocol, the development and consequences of its adoption, evolve at unimaginab...

This paper investigates digital and conventional technologies available in Greece suitable for Nearly Zero Energy Buildings that can be implemented in Vocational Schools and the impact that they will have on the present energy footprint of the schools’ buildings. Footprint-calculating technologies are presented and analyzed leading to outcomes on h...

The work addresses the significance of robotics in education, emphasizing its role in enhancing STEM skills through programming and sensory feedback. Scratch, a multimedia programming environment, is highlighted as a tool for robotic projects. Within Scratch, this work discusses data representation, distinguishing between visible and transparent da...

The primary research topic of this article is to create and synchronize an updated “digital storytelling” experience using various web-based digital tools in Vocational Education lessons. We organize various digital tools, such as a virtual map-construction of web timelines-virtual exhibition with the “artstep” tool, and a website with the busts of...

Nowadays, the need to explain the decisions or predictions made by Artificial Intelligence (AI) is emerging more than ever as AI applications are more complex. The research field of eXplainable Artificial Intelligence (XAI) tries to fulfill this need. XAI provides a way to help humans understand how an AI’s predictions and decisions come. The scope...

The purpose of this research article is to present an online intelligent pilot medical system designed to support the existing Greek pre-hospital medical care system. The proposed system effectively dispatches the available ambulances when an incident occurs and provides high quality medical services to the patients as well as transportation to the...

The concept of a metaverse, a virtual world that offers immersive experiences, has gained widespread interest in recent years. Designed as a simulation of the physical world, the metaverse covers all areas of human activity and provides a suitable platform for researchers in all disciplines, from health to sport, education, and art. This research i...

Open Educational Resources focuses on the production, licensing, use, and reuse of learning resources and their accessibility from open-access digital repositories as public goods. The article presents the dynamics of Open Educational Resources in the direction of the teaching of Electrokinesis in Vocational Education and Training. This drastically...

ARM64 emerges as a new transformative force that intersects with technology, sustainability and security, aiming to drastically reshape the current digital landscape. This paper provides a review of the ARM64 architecture, exploring its impact on various aspects of modern computing. Specifically, this review covers ARM64's architectural principles,...

The book analyzes in depth important aspects of modern distributed information systems. Initially, a general overview of Distributed Systems (DS) takes place, and the problems and challenges they face, their main characteristics and their relationship with Information Systems (IS) are analyzed. The basic design principles of DSs and the architectur...

Lately, there has been a rising trend towards integrating sustainability issues and implementing sustainable development (SD) goals into higher education, especially in the Information and Communication Technology (ICT) field. This paper presents the challenges of the introduction of education for sustainability in higher education institutions, an...

Despite the rapid development of technology, computer systems still rely heavily on passwords for security, which can be problematic. Although multi-factor authentication has been introduced, it is not completely effective against more advanced attacks. To address this, this study proposes a new two-factor authentication method that uses honeytoken...

The minimal 6TiSCH configuration provably suffers from large initial synchronization times, which results in an almost linear increase in the node energy consumption. One way to reduce the initial synchronization time is the use of an optimal scan period. Although the optimal scan period value has already been found in the literature, this value on...

In this paper, we survey architectural designs for the support of demanding ad hoc IoT applications, such as industrial IoTs. First, we examine the traditional software stack of nodes involved in centralized sensory applications. Then, we propose a highly distributed ad hoc architecture with increased node cooperation. Finally, we propose a secure...

In this paper, we examine architectural designs for the support of demanding ad hoc IoT applications, such as industrial and large-scale IoTs. First, we examine the traditional software stack of nodes involved in centralized sensory applications. Then, we propose a highly distributed ad hoc architecture with increased node cooperation. Finally, we...

The new reality of the coronavirus lockdown has prohibited the students’ physical presence in laboratories. Administrators, teachers, and students had to think of new alternatives to hold meetings by adopting a virtual format through the development of rapidly available and broadly accessible online resources. Online Open Educational Resources (OER...

This article introduces the ideas of Digital Twins (DTs) and Sustainability in the detailed program of the sector of Construction Works, Structured Environment, and Architectural Design, in upper secondary Vocational Education in Greece. The article overviews the curriculum of the sector and highlights the importance of the introduction of DTs and...

italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Contributions: This article explores the impact of environmental education interventions about e-waste recycling and management practices as well as about the energy usage of data centers (DCs) into the Information and Communication Technologies (ICTs)...

Technical education mainly focuses on practical training and skills-based learning and pays less attention to the theoretical background of its graduates. The officially instituted curriculum of Greek Vocational High Schools includes a wide range of Specialties among which is the Sector of Maritime Professions. In our proposal, we aim to introduce...

In secondary education, the diffusion and assimilation of knowledge should be achieved through a student-centered approach and facilitated, enriched and strengthened by the use of technological means and game-based approaches.In particular, the cultivation of historical thinking and the formation of historical consciousness by focusing on the essen...

After the completion of its third year of operation in 2022, the CyberSec4Europe pilot project (https://cybersec4europe.eu/) produced this ”Blue Book” (and delivered it as Deliverable D4.7) to serve as a Horizon Research Roadmap in the area of cyber security. To make this book a reality, the project put together a ”Task Force” of young and senior r...

This paper presents an educational game that aims to enhance students' logical, mathematical, linguistic, and other skills by introducing them to the landscape of Drapetsona, an area in the southern part of Piraeus, Greece, with rich labor history and many industrial monuments, highlighting its industrial heritage and its remains. This educational...

Computer systems rely heavily on passwords their safety for unreasonable long time, compared to the rapid progress and development of technology. Although insufficient authenti-cation mechanisms were enhanced by the use of two or more factors that resulted in new multi factor authentication schemes, more sophisticated and targeted attacks have show...

This article presents a novel multi-factor authentication mechanism that makes the authentication process robust to several attacks. The mechanism is using several databases to store the user key and an external USB device that the user carries with him. The system is divided into several groups, each one storing a part of the fragmented user key,...

The increased use of smart Electric Vehicles (EVs) and Plug-in Electric Vehicles (PEV) opened a new area of research and development. The number of EV charging sites has considerably increased in residential as well as in public areas. Within these EV charging sites, various entities need to communicate in a secure and efficient way. The Open Charg...

In this paper we examine traditional and novel software models for critical IoT applications. We propose a hybrid cellular IoT model that offers optimizations with respect to automated network management, re-configuration and optimized performance. This hybrid model utilizes the fog/edge computing model and can satisfy better the requirements of ti...

In this paper we examine traditional and novel software models for critical IoT applications. We propose a hybrid cellular IoT model that offers optimizations with respect to automated network management, re-configuration and optimized performance. This hybrid model utilizes the fog/edge computing model and can satisfy better the requirements of ti...

In this paper, we focus on the pedagogical use of the thinkable online environment in mobile applications development courses for Vocational Educational and Training (VET) specialties. The thunkable environment provides an easy-to-use interface for students and users with minimal knowledge of mobile applications programming and it can be also used...

This paper presents the modeling, design, implementation, and evaluation of a prototype Network Monitoring (ΝΜ) information system. First, a general overview of such management systems is provided highlighting the need for the visualization of network elements in order reliable network monitoring to be achieved. Moreover, the importance of monitori...

New critical educational issues arose during the implementation of distance education in the COVID-19 period. One of the most serious was the lack of non-verbal communication between students and teachers during distance education, as the physical contact of teaching was "mediated" by the digital environments of synchronous and asynchronous educati...

Nowadays computer programming is an essential skill that has grown in popularity in secondary education. In its block-based form, it is used to familiarize students with the basic concepts of programming before the students move on to text-based programming languages. The purpose of this paper is to investigate the transition from blocked-based to...

During the Covid-19 pandemic period, the transition from a physical classroom into a virtual online environment led to the redesign of the teaching practices so that it is pedagogically and technologically adapted to distance education. The main questions raised by the research concern, on the one hand, the possibilities for improvement in terms of...

The main purpose of this paper is to evaluate and redesign the workflow of the certification process for aircraft equipment of the Hellenic Air Force Accreditation Service (HAAS). The calibration cycle of a measurement device is analysed with the modelling tool "TIBCO Business Studio" and then improved successively in a recursive way. The paper eff...

An Internet of Things (IoT)-based service includes several devices and applications. A service’s security depends on the vulnerabilities of its individual components. Thus, because a security assessment is of high importance, it starts to be conducted in the design phase of the service’s model. The Stochastic Petri net (SPN) modelling method can su...

This work proposes a conceptual model for integrating education for sustainable development in a smart classroom learning environment. This environment may support the education that enables a more sustainable society for all the students and actively promotes the cultivation of the students’ environmental awareness. The model, which has in its cen...

The increased use of smart Electric Vehicles (EVs) and Plug-in Electric Vehicles (PEV) opened a new area of research and development. The number of EV charging sites has considerably increased in residential as well as in public areas. Within these EV charging sites, various entities need to communicate in a secure and efficient way. The Open Charg...

Although sufficient authentication mechanisms were enhanced by the use of two or more factors that resulted in new multi factor authentication schemes, more sophisticated and targeted attacks have shown they are also vulnerable. This research work proposes a novel two factor authentication system that incorporates honeytokens into the two factor au...

Cybersecurity is a never-ending battle against attackers, who try to identify and exploit misconfigurations and software vulnerabilities before being patched. In this ongoing conflict, it is important to analyse the properties of the vulnerability time series to understand when information systems are more vulnerable. We study computer systems’ sof...