Athena Vakali

Athena Vakali
Aristotle University of Thessaloniki | AUTH · Department of Informatics

phd in computer science

About

345
Publications
121,012
Reads
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6,678
Citations
Additional affiliations
September 1997 - present
Aristotle University of Thessaloniki
Position
  • Professor (Full) Web information systems

Publications

Publications (345)
Article
Full-text available
This work describes a novel end-to-end data ingestion and runtime processing pipeline, which is a core part of a technical solution aiming to monitor frailty indices of patients during and after treatment and improve their quality of life. The focus of this work is on the technical architectural details and the functionalities provided, which have...
Article
Full-text available
Local community detection is a widely used method for identifying groups of nodes starting from seeding nodes. The seed(s) are usually selected either randomly or based only on structural properties of the network. However, in many cases the choice of seed(s) incorporates external knowledge that attaches to these nodes an additional importance for...
Chapter
Full-text available
Within the most recent years, most of the cancer patients are older age, which implies the necessity to a better understanding of aging and cancer connection. This work presents the LifeChamps solution built on top of cutting-edge Big Data architecture and HPC infrastructure concepts. An innovative architecture was envisioned supported by the Big D...
Preprint
The high growth of Online Social Networks (OSNs) over the last few years has allowed automated accounts, known as social bots, to gain ground. As highlighted by other researchers, most of these bots have malicious purposes and tend to mimic human behavior, posing high-level security threats on OSN platforms. Moreover, recent studies have shown that...
Article
Full-text available
Fake news spreading is strongly connected with the human involvement as individuals tend to fall, adopt and circulate misinformation stories. Until recently, the role of human characteristics in fake news diffusion, in order to deeply understand and fight misinformation patterns, has not been explored to the full extent. This paper suggests a human...
Article
Full-text available
Although research interest in leader narcissism has been on the rise over the past few years, prior literature has predominantly discussed leader narcissism from a leader-centric perspective. In this paper, we provide a relational-based perspective of leader narcissism by examining the interaction between follower personality traits and leader narc...
Article
Full-text available
Given a network of Twitter users, can we capture their posting behavior over time, identify patterns that could probably describe, model or predict their activity? Can we identify temporal connectivity patterns that emerge from the use of specific attributes? More challengingly, are there particular attribute usage patterns which indicate an inhere...
Conference Paper
We explore how two paradoxical yet potentially complementary leader traits — grandiose narcissism and servant leadership — interact to affect follower state anxiety over a period of 316 days covering periods before and during the COVID-19 pandemic. Daily observations provided by 204 leaders and 1,131 followers show that grandiose admiration-seeking...
Conference Paper
This study extends prior research on the relational antecedents of employee voluntary turnover to examine the association between leader attachment orientations and employee retention (i.e., how long employees stay with their organization). Using a machine learning approach, attachment orientations and (as a control) Big Five personality traits of...
Article
Aggression in online social networks has been studied mostly from the perspective of machine learning, which detects such behavior in a static context. However, the way aggression diffuses in the network has received little attention as it embeds modeling challenges. In fact, modeling how aggression propagates from one user to another is an importa...
Article
Full-text available
Users in Online Social Networks (OSN) leave traces that reflect their personality characteristics. The study of these traces is important for several fields, such as social science, psychology, marketing, and others. Despite a marked increase in research on personality prediction based on online behavior, the focus has been heavily on individual pe...
Article
Full-text available
OSN platforms are under attack by intruders born and raised within their own ecosystems. These attacks have multiple scopes from mild critiques to violent offences targeting individual or community rights and opinions. Negative publicity on microblogging platforms, such as Twitter, is due to the infamous Twitter bots which highly impact posts’ circ...
Article
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Information propagation analysis in Online Social Networks (OSNs) sparks great interest due to its impact across different business sectors. In the wide range of OSNs, the famous micro-blogging service Twitter stands out for a plethora of reasons, such as the platform popularity and the ease of access to data. Activities like retweeting in the popu...
Preprint
Full-text available
Graph Representation Learning (GRL) has become essential for modern graph data mining and learning tasks. GRL aims to capture the graph's structural information and exploit it in combination with node and edge attributes to compute low-dimensional representations. While Graph Neural Networks (GNNs) have been used in state-of-the-art GRL architectur...
Article
Full-text available
Public key infrastructure (PKI) is widely used over the Internet to secure and to encrypt communication among parties. PKI involves digital certificates which are managed by certificate authorities (CAs) that authenticate users identity, in order to establish encrypted communication channels. The centralized operation model of CAs has already cause...
Article
Full-text available
Urbanization and knowledge economy have highly marked the new millennium. Urbanization brings new challenges which can be addressed by the knowledge economy, which opens up scientific and technical innovation opportunities. The enhancement of cities' intelligence has heavily impacted city transformation and sustainable decision-making based on urba...
Conference Paper
Although research interest in the dark triad traits, and in particular, leader narcissism, has been on the rise over the past few years, the prior literature has predominantly discussed leader narcissism from a leader-centric perspective. In this paper, we provide a relational-based perspective of leader narcissism by examining the interaction betw...
Article
Full-text available
Mosquito-Borne Diseases (MBDs) are known to be more prevalent in the tropics, and yet, in the last two decades, they are spreading to many other countries, especially in Europe. The set (volume) of environmental, meteorological and other spatio-temporally variable parameters affecting mosquito abundance makes the modeling and prediction tasks quite...
Preprint
Full-text available
BGP prefix hijacking is a critical threat to the resilience and security of communications in the Internet. While several mechanisms have been proposed to prevent, detect or mitigate hijacking events, it has not been studied how to accurately quantify the impact of an ongoing hijack. When detecting a hijack, existing methods do not estimate how man...
Article
Full-text available
Due to their confidence and dominance, narcissistic leaders oftentimes can be perceived favorably by followers, in particular during times of uncertainty. In this study, we propose and examine the relationship between narcissistic leaders and followers who are prone to experience uncertainty intensely and frequently in general, namely highly anxiou...
Preprint
Full-text available
In today's connected society, many people rely on mHealth and self-tracking (ST) technology to help them break their sedentary lifestyle and stay fit. However, there is scarce evidence of such technological interventions' effectiveness, and there are no standardized methods to evaluate the short- and long-term impact of such technologies on people'...
Article
Full-text available
The extensive use of Information and Communication Technologies and the consequent unprecedented generation of data have radically transformed the way we understand cities today. The vision of smart cities considers technology as an enabling force for the emergence of new forms of intelligence and collaboration, enhancing, thus, the problem-solving...
Article
Given a tabular dataset which should be graphically represented, how could the current complex visualization pipeline be improved? Could we produce a more visually enriched final representation, while minimizing the user intervention? Most of the existing approaches lack in capacity to provide a simplified end-to-end solution and leave the intricat...
Chapter
Cloud services have become increasingly popular during the past few years. Through these services, users can store their data remotely and access them any time and from anywhere. These services are offered by centralized systems where an organization or company usually offers their resources to users. The centralized nature of these systems causes...
Article
Full-text available
Crowdsourcing offers an invaluable toolkit for obtaining dynamic trends and insights from social media data analytics, enabling the capture of the wisdom of the crowds. The plethora of available platforms requires the appropriate definition of data schemas and techniques to allow for efficient knowledge extraction from unstructured social media use...
Preprint
Users in Online Social Networks (OSN) leaves traces that reflect their personality characteristics. The study of these traces is important for a number of fields, such as a social science, psychology, OSN, marketing, and others. Despite a marked increase on research in personality prediction on based on online behavior the focus has been heavily on...
Preprint
We examine the relationship between leader grandiose narcissism, composed of admiration and rivalry, and corporate fundraising success in a sample of 2377 organizational leaders. To examine a large sample of leaders, we applied a machine-learning algorithm to predict leaders' personality scores based on leaders' Twitter profiles. We found that admi...
Article
Full-text available
We examine the relationship between leader grandiose narcissism, composed of admiration and rivalry, and corporate fundraising success in a sample of 2377 organizational leaders. To examine a large sample of leaders, we applied a machine-learning algorithm to predict leaders' personality scores based on leaders' Twitter profiles. We found that admi...
Article
Full-text available
As the confidentiality and integrity of modern health infrastructures is threatened by intrusions and real-time attacks related to privacy and cyber-security, there is a need for proposing novel methodologies to predict future incidents and identify new threat patterns. The main scope of this article is to propose an advanced extension to current I...
Preprint
Full-text available
Aggression in online social networks has been studied up to now, mostly with several machine learning methods which detect such behavior in a static context. However, the way aggression diffuses in the network has received little attention as it embeds modeling challenges. In fact, modeling how aggression propagates from one user to another, is an...
Conference Paper
Full-text available
Smart cities have emerged significantly since their initial appearance in 1990s, more and more cities around the world are striving to gain intelligence and in this regard the need for standardization and performance measurement grows. Given the current challenges in the field of smart cities, this work revisits the proposed "cityDNA" framework whi...
Article
Full-text available
Cyberbullying and cyberaggression are increasingly worrisome phenomena affecting people across all demographics. More than half of young social media users worldwide have been exposed to such prolonged and/or coordinated digital harassment. Victims can experience a wide range of emotions, with negative consequences such as embarrassment, depression...
Conference Paper
Contemporary societies are challenged by many social issues, lots of which relate with environmental threats. Plastic waste's impact on societal well being, economy, and environment has already triggered the need for its revaluation and its transformation into an asset which can inspire and mobilize innovative solutions. This work envisions trusted...
Conference Paper
Software design and development technologies evolve very fast and in unpredicted rates, posing many challenges for programmers who strive to use them properly and to be up-to-date, especially since software development demands teamwork and collaboration. As a result, Question and Answer (Q&A) sites, like Stack Overflow, have seen large growth. The...
Preprint
Full-text available
Cyberbullying and cyberaggression are increasingly worrisome phenomena affecting people across all demographics. More than half of young social media users worldwide have been exposed to such prolonged and/or coordinated digital harassment. Victims can experience a wide range of emotions, with negative consequences such as embarrassment, depression...
Conference Paper
Hate speech, offensive language, sexism, racism, and other types of abusive behavior have become a common phenomenon in many online social media platforms. In recent years, such diverse abusive behaviors have been manifesting with increased frequency and levels of intensity. Despite social media's efforts to combat online abusive behaviors this pro...
Conference Paper
Full-text available
Smart technologies advancements, emerging markets competition and sustainability needs have radically changed tourism and transport sectors. The key features of this change are the exploitation of evolving Big Data in the business intelligence context, the development of customized services tailored to the needs of consumers with the purpose of imp...
Article
The proliferation of social platforms and the enhanced connectivity have led people of different age groups, ethnicity, social or economic status to reveal a great deal about themselves online. Data collected from online social networks (OSN) provides social, economic, and cultural information which can be utilized by governments, policy makers, au...
Article
Fake news has become a problem of great impact in our information driven society because of the continuous and intense fakesters content distribution. Information quality in news feeds is under questionable veracity calling for automated tools to detect fake news articles. Due to many faces of fakesters, creating such tool is a challenging problem....
Article
Full-text available
Smart cities (SCs) are becoming highly sophisticated ecosystems at which innovative solutions and smart services are being deployed. These ecosystems consider SCs as data production and sharing engines, setting new challenges for building effective SC architectures and novel services. The aim of this article is to “connect the pieces” among Data Sc...
Article
The proliferation of social platforms and the enhanced connectivity have led people of different age groups, ethnicity, social or economic status to reveal a great deal about themselves online. Data collected from online social networks (OSN) provides social, economic, and cultural information which can be utilized by governments, policy makers, au...
Conference Paper
Full-text available
As smart cities infrastructures mature, data becomes a valuable asset which can radically improve city services and tools. Registration, acquisition and utilization of data, which will be transformed into smart services, are becoming more necessary than ever. Online social networks with their enormous momentum are one of the main sources of urban d...
Article
Full-text available
Hate speech, offensive language, sexism, racism and other types of abusive behavior have become a common phenomenon in many online social media platforms. In recent years, such diverse abusive behaviors have been manifesting with increased frequency and levels of intensity. This is due to the openness and willingness of popular media platforms, suc...
Conference Paper
Full-text available
In recent years, offensive, abusive and hateful language, sexism, racism and other types of aggressive and cyberbullying behavior have been manifesting with increased frequency, and in many online social media platforms. In fact, past scientific work focused on studying these forms in popular media, such as Facebook and Twitter. Building on such wo...
Conference Paper
Social networks have become big data production engines and their analytics can reveal insightful trending topics, such that hidden knowledge can be utilized in various applications and settings. This paper addresses the problem of popular topics’ and trends’ early prediction out of social networks data streams which demand distributed software arc...
Conference Paper
Full-text available
Common approaches to text categorization essentially rely either on n-gram counts or on word embeddings. This presents important difficulties in highly dynamic or quickly-interacting environments, where the appearance of new words and/or varied misspellings is the norm. A paradigmatic example of this situation is abusive online behavior, with socia...
Conference Paper
Full-text available
Over the past few years, online bullying and aggression have become increasingly prominent, and manifested in many different forms on social media. However, there is little work analyzing the characteristics of abusive users and what distinguishes them from typical social media users. In this paper, we start addressing this gap by analyzing tweets...
Article
The present study compared the experience of emotion in social interactions that take place face to face (FtF), co-presently, and those that take place online, in computer-mediated communications (CMC). For a period of ten days participants reported how intensely they experienced positive and negative emotions in CMC and in FtF interactions they ha...
Article
Full-text available
Online text sources form evolving large scale data repositories out of which valuable knowledge about human emotions can be derived. Beyond the primary emotions which refer to the global emotional signals, deeper understanding of a wider spectrum of emotions is important to detect online public views and attitudes. The present work is motivated by...
Article
Social media and mobile devices have revolutionized the way people communicate and share information in various contexts, such as in cities. In today’s “smart” cities, massive amounts of multiple forms of geolocated content is generated daily in social media, out of which knowledge for social interactions and urban dynamics can be derived. This wor...
Conference Paper
Full-text available
In recent years, bullying and aggression against social media users have grown significantly, causing serious consequences to victims of all demographics. Nowadays, cyberbullying affects more than half of young social media users worldwide, suffering from prolonged and/or coordinated digital harassment. Also, tools and technologies geared to unders...