<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>13</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Antigoni-Maria Founta</style></author><author><style face="normal" font="default" size="100%">Constantinos Djouvas</style></author><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Ilias Leontiadis</style></author><author><style face="normal" font="default" size="100%">Jeremy Blackburn</style></author><author><style face="normal" font="default" size="100%">Gianluca Stringhini</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Michael Sirivianos</style></author><author><style face="normal" font="default" size="100%">Nicolas Kourtellis</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Large Scale Crowdsourcing and Characterization of Twitter Abusive Behavior</style></title><tertiary-title><style face="normal" font="default" size="100%">ICWSM-18</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2018</style></year></dates><publisher><style face="normal" font="default" size="100%">AAAI</style></publisher><pub-location><style face="normal" font="default" size="100%">Stanford, California</style></pub-location><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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 work, we present an 8-month study of the various forms of abusive behavior on Twitter, in a holistic fashion. Departing from past work, we examine a wide variety of labeling schemes, which cover different forms of abusive behavior, at the same time. We propose an incremental and iterative methodology, that utilizes the power of crowdsourcing to annotate a large scale collection of tweets with a set of abuse-related labels. In fact, by applying our methodology including statistical analysis for label merging or elimination, we identify a reduced but robust set of labels. Finally, we offer a first overview and findings of our collected and annotated dataset of 100 thousand tweets, which we make publicly available for further scientific exploration.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>10</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Joan Serrà</style></author><author><style face="normal" font="default" size="100%">Ilias Leontiadis</style></author><author><style face="normal" font="default" size="100%">Dimitris Spathis</style></author><author><style face="normal" font="default" size="100%">Gianluca Stringhini</style></author><author><style face="normal" font="default" size="100%">Jeremy Blackburn</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Class-based Prediction Errors to Categorize Text with Out-of-vocabulary Words</style></title><tertiary-title><style face="normal" font="default" size="100%">ALW1'17</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2017</style></year></dates><pub-location><style face="normal" font="default" size="100%">Vancouver, Canada</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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 social networks and media platforms struggling to effectively combat uncommon or non-blacklisted hate words. To better deal with these issues in those fast-paced environments, we propose using the error signal of class-based language models as input to text classification algorithms. In particular, we train a next-character prediction model for any given class, and then exploit the error of such class-based models to inform a neural network classifier. This way, we shift from the ability to describe seen documents to the ability to predict unseen content. Preliminary studies using out-of-vocabulary splits from abusive tweet data show promising results, outperforming competitive text categorization strategies by 4–11%.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>10</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Nicolas Kourtellis</style></author><author><style face="normal" font="default" size="100%">Jeremy Blackburn</style></author><author><style face="normal" font="default" size="100%">Emiliano De Cristofaro</style></author><author><style face="normal" font="default" size="100%">Gianluca Stringhini</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Detecting Aggressors and Bullies on Twitter</style></title><secondary-title><style face="normal" font="default" size="100%">Proceedings of the 26th International Conference on World Wide Web Companion</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">WWW '17 Companion</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">crowdsourcing</style></keyword><keyword><style  face="normal" font="default" size="100%">cyber-aggression</style></keyword><keyword><style  face="normal" font="default" size="100%">cyberbullying</style></keyword><keyword><style  face="normal" font="default" size="100%">Twitter</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2017</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dl.acm.org/citation.cfm?id=3054211</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pub-location><style face="normal" font="default" size="100%">Perth, Australia</style></pub-location><pages><style face="normal" font="default" size="100%">767--768</style></pages><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Online social networks constitute an integral part of people's every day social activity and the existence of aggressive and bullying phenomena in such spaces is inevitable. In this work, we analyze user behavior on Twitter in an effort to detect cyberbullies and cuber-aggressors by considering specific attributes of their online activity using machine learning classifiers.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>10</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Nicolas Kourtellis</style></author><author><style face="normal" font="default" size="100%">Jeremy Blackburn</style></author><author><style face="normal" font="default" size="100%">Emiliano De Cristofaro</style></author><author><style face="normal" font="default" size="100%">Gianluca Stringhini</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Hate is not Binary: Studying Abusive Behavior of #GamerGate on Twitter</style></title><tertiary-title><style face="normal" font="default" size="100%">HT '17</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2017</style></year></dates><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pub-location><style face="normal" font="default" size="100%">Prague, Czech Republic</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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 containing a great amount of abusiveness. We focus on a Twitter dataset revolving around the Gamergate controversy, which led to many incidents of cyberbullying and cyberaggression on various gaming and social media platforms. We study the properties of the users tweeting about Gamergate, the content they post, and the differences in their behavior compared to typical Twitter users.&lt;/p&gt;

&lt;p&gt;We find that while their tweets are often seemingly about aggressive and hateful subjects, ``Gamergaters'' do not exhibit common expressions of online anger, and in fact primarily differ from typical users in that their tweets are less joyful. They are also more engaged than typical Twitter users, which is an indication as to how and why this controversy is still ongoing. Surprisingly, we find that Gamergaters are less likely to be suspended by Twitter, thus we analyze their properties to identify differences from typical users and what may have led to their suspension. We perform an unsupervised machine learning analysis to detect clusters of users who, though currently active, could be considered for suspension since they exhibit similar behaviors with suspended users. Finally, we confirm the usefulness of our analyzed features by emulating the Twitter suspension mechanism with a supervised learning method, achieving very good precision and recall.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>10</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Nicolas Kourtellis</style></author><author><style face="normal" font="default" size="100%">Jeremy Blackburn</style></author><author><style face="normal" font="default" size="100%">Emiliano De Cristofaro</style></author><author><style face="normal" font="default" size="100%">Gianluca Stringhini</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Mean Birds: Detecting Aggression and Bullying on Twitter</style></title><tertiary-title><style face="normal" font="default" size="100%">WebSci '17</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2017</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://arxiv.org/abs/1702.06877</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pub-location><style face="normal" font="default" size="100%">Troy, NY, USA</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;In recent years, bullying and aggression against users on social media have grown significantly, causing serious consequences to victims of all demographics. In particular, cyberbullying affects more than half of young social media users worldwide, and has also led to teenage suicides, prompted by prolonged and/or coordinated digital harassment. Nonetheless, tools and technologies for understanding and mitigating it are scarce and mostly ineffective. In this paper, we present a principled and scalable approach to detect bullying and aggressive behavior on Twitter. We propose a robust methodology for extracting text, user, and network-based attributes, studying the properties of cyberbullies and aggressors, and what features distinguish them from regular users. We find that bully users post less, participate in fewer online communities, and are less popular than normal users, while aggressors are quite popular and tend to include more negativity in their posts. We evaluate our methodology using a corpus of 1.6M tweets posted over 3 months, and show that machine learning classification algorithms can accurately detect users exhibiting bullying and aggressive behavior, achieving over 90% AUC.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>10</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Nicolas Kourtellis</style></author><author><style face="normal" font="default" size="100%">Jeremy Blackburn</style></author><author><style face="normal" font="default" size="100%">Emiliano De Cristofaro</style></author><author><style face="normal" font="default" size="100%">Gianluca Stringhini</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Measuring #GamerGate: A Tale of Hate, Sexism, and Bullying</style></title><secondary-title><style face="normal" font="default" size="100%">Proceedings of the 26th International Conference on World Wide Web Companion</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">WWW '17 Companion</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2017</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dl.acm.org/citation.cfm?id=3053890</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pub-location><style face="normal" font="default" size="100%">Perth, Australia</style></pub-location><pages><style face="normal" font="default" size="100%">1285-1290</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Over the past few years, online aggression and abusive behaviors have occurred in many different forms and on a variety of platforms. In extreme cases, these incidents have evolved into hate, discrimination, and bullying, and even materialized into real-world threats and attacks against individuals or groups. In this paper, we study the Gamergate controversy. Started in August 2014 in the online gaming world, it quickly spread across various social networking platforms, ultimately leading to many incidents of cyberbullying and cyberaggression. We focus on Twitter, presenting a measurement study of a dataset of 340k unique users and 1.6M tweets to study the properties of these users, the content they post, and how they differ from random Twitter users. We find that users involved in this &quot;Twitter war&quot; tend to have more friends and followers, are generally more engaged and post tweets with negative sentiment, less joy, and more hate than random users. We also perform preliminary measurements on how the Twitter suspension mechanism deals with such abusive behaviors. While we focus on Gamergate, our methodology to collect and analyze tweets related to aggressive and bullying activities is of independent interest.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Maria Giatsoglou</style></author><author><style face="normal" font="default" size="100%">Manolis G. Vozalis</style></author><author><style face="normal" font="default" size="100%">Konstantinos Diamantaras</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">George Sarigiannidis</style></author><author><style face="normal" font="default" size="100%">Konstantinos Ch. Chatzisavvas</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Sentiment analysis leveraging emotions and word embeddings</style></title><secondary-title><style face="normal" font="default" size="100%">Expert Systems with Applications</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Online user reviews</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2017</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S095741741630584X</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">69</style></volume><pages><style face="normal" font="default" size="100%">214 - 224</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Abstract Sentiment analysis and opinion mining are valuable for extraction of useful subjective information out of text documents. These tasks have become of great importance, especially for business and marketing professionals, since online posted products and services reviews impact markets and consumers shifts. This work is motivated by the fact that automating retrieval and detection of sentiments expressed for certain products and services embeds complex processes and pose research challenges, due to the textual phenomena and the language specific expression variations. This paper proposes a fast, flexible, generic methodology for sentiment detection out of textual snippets which express people’s opinions in different languages. The proposed methodology adopts a machine learning approach with which textual documents are represented by vectors and are used for training a polarity classification model. Several documents’ vector representation approaches have been studied, including lexicon-based, word embedding-based and hybrid vectorizations. The competence of these feature representations for the sentiment classification task is assessed through experiments on four datasets containing online user reviews in both Greek and English languages, in order to represent high and weak inflection language groups. The proposed methodology requires minimal computational resources, thus, it might have impact in real world scenarios where limited resources is the case.&lt;/p&gt;
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Beutel</style></author><author><style face="normal" font="default" size="100%">Christos Faloutsos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">ND-SYNC: Detecting Synchronized Fraud Activities</style></title><secondary-title><style face="normal" font="default" size="100%">Advances in Knowledge Discovery and Data Mining, 19th Pacific-Asia Conference, PAKDD 2015, Ho Chi Minh City, Vietnam, May 19-22, 2015, Proceedings, Part II</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2015</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1007/978-3-319-18032-8_16</style></url></web-urls></urls><pages><style face="normal" font="default" size="100%">201â€“214</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Maria Giatsoglou</style></author><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Neil Shah</style></author><author><style face="normal" font="default" size="100%">Christos Faloutsos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Cao, Tru</style></author><author><style face="normal" font="default" size="100%">Lim, Ee-Peng</style></author><author><style face="normal" font="default" size="100%">Zhou, Zhi-Hua</style></author><author><style face="normal" font="default" size="100%">Ho, Tu-Bao</style></author><author><style face="normal" font="default" size="100%">Cheung, David</style></author><author><style face="normal" font="default" size="100%">Motoda, Hiroshi</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Retweeting Activity on Twitter: Signs of Deception</style></title><secondary-title><style face="normal" font="default" size="100%">PAKDD (1)</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2015</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">9077</style></volume><pages><style face="normal" font="default" size="100%">122-134</style></pages><isbn><style face="normal" font="default" size="100%">978-3-319-18037-3</style></isbn><language><style face="normal" 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font="default" size="100%">Branty: A Social Media Ranking Tool for Brands</style></title><secondary-title><style face="normal" font="default" size="100%">ECML/PKDD (3)</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">8726</style></volume><pages><style face="normal" font="default" size="100%">432-435</style></pages><isbn><style face="normal" font="default" size="100%">978-3-662-44844-1</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" 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font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">62</style></volume><pages><style face="normal" font="default" size="100%">241-256</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Maria Giatsoglou</style></author><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Lin, Xuemin</style></author><author><style face="normal" font="default" size="100%">Manolopoulos, Yannis</style></author><author><style face="normal" font="default" size="100%">Srivastava, Divesh</style></author><author><style face="normal" font="default" size="100%">Huang, Guangyan</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Community Detection in Social Media by Leveraging Interactions and Intensities</style></title><secondary-title><style face="normal" font="default" size="100%">WISE (2)</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">community detection</style></keyword><keyword><style  face="normal" font="default" size="100%">user weighted interaction networks</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">8181</style></volume><pages><style face="normal" font="default" size="100%">57-72</style></pages><isbn><style face="normal" font="default" size="100%">978-3-642-41153-3</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Samaras, Christos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Maria Giatsoglou</style></author><author><style face="normal" font="default" size="100%">Despoina Chatzakou</style></author><author><style face="normal" font="default" size="100%">Angelis, Lefteris</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Ketikidis, Panayiotis H.</style></author><author><style face="normal" font="default" size="100%">Margaritis, Konstantinos G.</style></author><author><style face="normal" font="default" size="100%">Vlahavas, Ioannis P.</style></author><author><style face="normal" font="default" size="100%">Chatzigeorgiou, Alexander</style></author><author><style face="normal" font="default" size="100%">Eleftherakis, George</style></author><author><style face="normal" font="default" size="100%">Stamelos, Ioannis</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Requirements and architecture design principles for a smart city experiment with sensor and social networks integration</style></title><secondary-title><style face="normal" font="default" size="100%">Panhellenic Conference on Informatics</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pages><style face="normal" font="default" size="100%">327-334</style></pages><isbn><style face="normal" font="default" size="100%">978-1-4503-1969-0</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Symeon Papadopoulos</style></author><author><style face="normal" font="default" size="100%">Sagonas, Christos</style></author><author><style face="normal" font="default" size="100%">Yiannis Kompatsiaris</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Li, Shipeng</style></author><author><style face="normal" font="default" size="100%">El-Saddik, Abdulmotaleb</style></author><author><style face="normal" font="default" size="100%">Wang, Meng</style></author><author><style face="normal" font="default" size="100%">Mei, Tao</style></author><author><style face="normal" font="default" size="100%">Sebe, Nicu</style></author><author><style face="normal" font="default" size="100%">Yan, Shuicheng</style></author><author><style face="normal" font="default" size="100%">Hong, Richang</style></author><author><style face="normal" font="default" size="100%">Gurrin, Cathal</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Semi-supervised Concept Detection by Learning the Structure of Similarity Graphs</style></title><secondary-title><style face="normal" font="default" size="100%">MMM (1)</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">7732</style></volume><pages><style face="normal" font="default" size="100%">1-12</style></pages><isbn><style face="normal" font="default" size="100%">978-3-642-35725-1</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We present an approach for detecting concepts in images bya graph-based semi-supervised learning scheme. The proposed approach builds a similarity graph between both the labeled and unlabeled images of the collection and uses the Laplacian Eigemaps of the graph as features for training concept detectors. Therefore, it offers multiple options for fusing different image features. In addition, we present an incremental learning scheme that, given a set of new unlabeled images, efficiently performs the computation of the Laplacian Eigenmaps. We evaluate the performance of our approach both on synthetic datasets and on MIR Flickr, comparing it with high-performance state-of-the-art learning schemes with competitive and in some cases superior results.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Laskaris, Nikolaos A.</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Mani-Web: Large-Scale Web Graph Embedding via Laplacian Eigenmap Approximation</style></title><secondary-title><style face="normal" font="default" size="100%">IEEE Transactions on Systems, Man, and Cybernetics, Part C</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Laplacian eigenmap</style></keyword><keyword><style  face="normal" font="default" size="100%">large scale</style></keyword><keyword><style  face="normal" font="default" size="100%">manifold learning</style></keyword><keyword><style  face="normal" font="default" size="100%">spectral graph theory</style></keyword><keyword><style  face="normal" font="default" size="100%">web communities</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><number><style face="normal" font="default" size="100%">6</style></number><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">879-888</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The Web as a graph can be embedded in a lowdimensionalspace where its geometry can be visualized and studiedin order to mine interesting patterns such as web communities.The existing algorithms operate on small-to-medium-scalegraphs; thus, we propose a close to linear time algorithm calledMani-Web suitable for large-scale graphs. The result is similarto the one produced by the manifold-learning technique Laplacianeigenmap that is tested on artificial manifolds and real webgraphs.Mani-Web can also be used as a general-purpose manifoldlearning/dimensionality-reductiontechnique as long as the datacan be represented as a graph.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Maria Giatsoglou</style></author><author><style face="normal" font="default" size="100%">Antaris, Stefanos</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Mille, Alain</style></author><author><style face="normal" font="default" size="100%">Gandon, Fabien L.</style></author><author><style face="normal" font="default" size="100%">Misselis, Jacques</style></author><author><style face="normal" font="default" size="100%">Rabinovich, Michael</style></author><author><style face="normal" font="default" size="100%">Staab, Steffen</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Social networking trends and dynamics detection via a cloud-based framework design</style></title><secondary-title><style face="normal" font="default" size="100%">WWW (Companion Volume)</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">cloud service deployment</style></keyword><keyword><style  face="normal" font="default" size="100%">microblogs and blogosphere dynamics</style></keyword><keyword><style  face="normal" font="default" size="100%">Social networks social</style></keyword><keyword><style  face="normal" font="default" size="100%">Web Data Clustering</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pages><style face="normal" font="default" size="100%">1213-1220</style></pages><isbn><style face="normal" font="default" size="100%">978-1-4503-1230-1</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Srivastava, Lara</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Alvarez, Federico</style></author><author><style face="normal" font="default" size="100%">Cleary, Frances</style></author><author><style face="normal" font="default" size="100%">Daras, Petros</style></author><author><style face="normal" font="default" size="100%">Domingue, John</style></author><author><style face="normal" font="default" size="100%">Galis, Alex</style></author><author><style face="normal" font="default" size="100%">Garcia, Ana</style></author><author><style face="normal" font="default" size="100%">Gavras, Anastasius</style></author><author><style face="normal" font="default" size="100%">Karnouskos, Stamatis</style></author><author><style face="normal" font="default" size="100%">Krco, Srdjan</style></author><author><style face="normal" font="default" size="100%">Li, Man-Sze</style></author><author><style face="normal" font="default" size="100%">Lotz, Volkmar</style></author><author><style face="normal" font="default" size="100%">Müller, Henning</style></author><author><style face="normal" font="default" size="100%">Salvadori, Elio</style></author><author><style face="normal" font="default" size="100%">Sassen, Anne-Marie</style></author><author><style face="normal" font="default" size="100%">Schaffers, Hans</style></author><author><style face="normal" font="default" size="100%">Stiller, Burkhard</style></author><author><style face="normal" font="default" size="100%">Tselentis, Georgios</style></author><author><style face="normal" font="default" size="100%">Turkama, Petra</style></author><author><style face="normal" font="default" size="100%">Zahariadis, Theodore B.</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Towards a Narrative-Aware Design Framework for Smart Urban Environments</style></title><secondary-title><style face="normal" font="default" size="100%">Future Internet Assembly</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">7281</style></volume><pages><style face="normal" font="default" size="100%">166-177</style></pages><isbn><style face="normal" font="default" size="100%">978-3-642-30240-4</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Anthopoulos, Leonidas G.</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Alvarez, Federico</style></author><author><style face="normal" font="default" size="100%">Cleary, Frances</style></author><author><style face="normal" font="default" size="100%">Daras, Petros</style></author><author><style face="normal" font="default" size="100%">Domingue, John</style></author><author><style face="normal" font="default" size="100%">Galis, Alex</style></author><author><style face="normal" font="default" size="100%">Garcia, Ana</style></author><author><style face="normal" font="default" size="100%">Gavras, Anastasius</style></author><author><style face="normal" font="default" size="100%">Karnouskos, Stamatis</style></author><author><style face="normal" font="default" size="100%">Krco, Srdjan</style></author><author><style face="normal" font="default" size="100%">Li, Man-Sze</style></author><author><style face="normal" font="default" size="100%">Lotz, Volkmar</style></author><author><style face="normal" font="default" size="100%">Müller, Henning</style></author><author><style face="normal" font="default" size="100%">Salvadori, Elio</style></author><author><style face="normal" font="default" size="100%">Sassen, Anne-Marie</style></author><author><style face="normal" font="default" size="100%">Schaffers, Hans</style></author><author><style face="normal" font="default" size="100%">Stiller, Burkhard</style></author><author><style face="normal" font="default" size="100%">Tselentis, Georgios</style></author><author><style face="normal" font="default" size="100%">Turkama, Petra</style></author><author><style face="normal" font="default" size="100%">Zahariadis, Theodore B.</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Urban Planning and Smart Cities: Interrelations and Reciprocities</style></title><secondary-title><style face="normal" font="default" size="100%">Future Internet Assembly</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">7281</style></volume><pages><style face="normal" font="default" size="100%">178-189</style></pages><isbn><style face="normal" font="default" size="100%">978-3-642-30240-4</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Symeon Papadopoulos</style></author><author><style face="normal" font="default" size="100%">Christos Zigkolis</style></author><author><style face="normal" font="default" size="100%">Kapiris, Stefanos</style></author><author><style face="normal" font="default" size="100%">Yiannis Kompatsiaris</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Natale, Francesco G. B. De</style></author><author><style face="normal" font="default" size="100%">Bimbo, Alberto Del</style></author><author><style face="normal" font="default" size="100%">Hanjalic, Alan</style></author><author><style face="normal" font="default" size="100%">Manjunath, B. S.</style></author><author><style face="normal" font="default" size="100%">Satoh, Shin’ichi</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">City exploration by use of spatio-temporal analysis and clustering of user contributed photos</style></title><secondary-title><style face="normal" font="default" size="100%">ICMR</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Clustering</style></keyword><keyword><style  face="normal" font="default" size="100%">content browsing</style></keyword><keyword><style  face="normal" font="default" size="100%">landmark/event detection</style></keyword><keyword><style  face="normal" font="default" size="100%">spatio-temporal mining</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pages><style face="normal" font="default" size="100%">65</style></pages><isbn><style face="normal" font="default" size="100%">978-1-4503-0336-1</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We present a technical demonstration of an online city explorationapplication that helps users identify interesting spotsin a city by use of spatio-temporal analysis and clusteringof user contributed photos. Our framework analyzes thespatial distribution of large city-centered collections of usercontributed photos at different time scales in order to indexthe most popular spots of a city in a time-aware manner.Subsequently, the photo sets belonging to the same spatiotemporalcontext are clustered in order to extract representativephotos for each spot. The resulting applicationenables users to obtain flexible summaries of the most importantspots in a city given a temporal slice (time of theday, month, season). The demonstration will be based on aphoto dataset covering major European cities.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tsagkalidou, Katerina</style></author><author><style face="normal" font="default" size="100%">Vassiliki A. Koutsonikola</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Konstantinos Kafetsios</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">D’Mello, Sidney K.</style></author><author><style face="normal" font="default" size="100%">Graesser, Arthur C.</style></author><author><style face="normal" font="default" size="100%">Schuller, Björn</style></author><author><style face="normal" font="default" size="100%">Martin, Jean-Claude</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Emotional Aware Clustering on Micro-blogging Sources</style></title><secondary-title><style face="normal" font="default" size="100%">ACII (1)</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Microblogging services</style></keyword><keyword><style  face="normal" font="default" size="100%">Sentiment analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">web clustering</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">6974</style></volume><pages><style face="normal" font="default" size="100%">387-396</style></pages><isbn><style face="normal" font="default" size="100%">978-3-642-24599-2</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Microblogging services have nowadays become a very popularcommunication tool among Internet users. Since millions of usersshare opinions on different aspects of life everyday, microblogging websites are considered as a credible source for exploring both factual and subjective information. This fact has inspired research in the area of automatic sentiment analysis. In this paper we propose an emotional aware clustering approach which performs sentiment analysis of users tweets onthe basis of an emotional dictionary and groups tweets according to the degree they express a specific set of emotions. Experimental evaluations on datasets derived from Twitter prove the efficiency of the proposed approach.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Maaradji, Abderrahmane</style></author><author><style face="normal" font="default" size="100%">Hacid, Hakim</style></author><author><style face="normal" font="default" size="100%">Skraba, Ryan</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Social Web Mashups Full Completion via Frequent Sequence Mining</style></title><secondary-title><style face="normal" font="default" size="100%">SERVICES</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Mashups</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence mining</style></keyword><keyword><style  face="normal" font="default" size="100%">Social networks</style></keyword><keyword><style  face="normal" font="default" size="100%">Web services</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">9-16</style></pages><isbn><style face="normal" font="default" size="100%">978-1-4577-0879-4</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;In this paper we address the problem of WebMashups full completion which consists of predicting themost suitable set of (combined) services that successfully meetthe goals of an end-user Mashup, given the current service(or composition of services) initially supplied. We model fullcompletion as a frequent sequence mining problem and weshow how existing algorithms can be applied in this context.To overcome some limitations of the frequent sequence miningalgorithms, e.g., efficiency and recommendation granularity,we propose FESMA, a new and efficient algorithm for computingfrequent sequences of services and recommending completions.FESMA also integrates a social dimension, extractedfrom the transformation of user ? service interactions intouser ? user interactions, building an implicit graph thathelps to better predict completions of services in a fashiontailored to individual users. Evaluations show that FESMAis more efficient outperforming the existing algorithms evenwith the consideration of the social dimension. Our proposalhas been implemented in a prototype, SoCo, developed at BellLabs.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gabriel, Hans-Henning</style></author><author><style face="normal" font="default" size="100%">Spiliopoulou, Myra</style></author><author><style face="normal" font="default" size="100%">Stachtiari, Emmanouela</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Boissier, Olivier</style></author><author><style face="normal" font="default" size="100%">Benatallah, Boualem</style></author><author><style face="normal" font="default" size="100%">Papazoglou, Mike P.</style></author><author><style face="normal" font="default" size="100%">Ras, Zbigniew W.</style></author><author><style face="normal" font="default" size="100%">Hacid, Mohand-Said</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Summarization Meets Visualization on Online Social Networks</style></title><secondary-title><style face="normal" font="default" size="100%">Web Intelligence</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Clustering</style></keyword><keyword><style  face="normal" font="default" size="100%">communities</style></keyword><keyword><style  face="normal" font="default" size="100%">community representatives</style></keyword><keyword><style  face="normal" font="default" size="100%">social network summarization</style></keyword><keyword><style  face="normal" font="default" size="100%">social network visualization</style></keyword><keyword><style  face="normal" font="default" size="100%">Social networks</style></keyword><keyword><style  face="normal" font="default" size="100%">visualization</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">475-478</style></pages><isbn><style face="normal" font="default" size="100%">978-0-7695-4513-4</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Getting an overview of a large online social networkand deciding which communities to join is a challengingtask for a new user. We propose a method that maps a largenetwork into a smaller graph with two kinds of nodes: a nodeof the first kind is representative of a community; a node ofthe second kind is neighbor to a representative and reflectsthe semantics of that community. Our approach encompassesa learning and ranking algorithm that derives this smallergraph from the original one, and a visualization algorithmthat returns a graph layout to the observer. We report on ourresults on inspecting the network of a folksonomy.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">ul Islam, Saif</style></author><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Pierson, Jean-Marc</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Kranzlmller, Dieter</style></author><author><style face="normal" font="default" size="100%">Tjoa, A Min</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Utilization-Aware Redirection Policy in CDN: A Case for Energy Conservation</style></title><secondary-title><style face="normal" font="default" size="100%">ICT-GLOW</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CDNs</style></keyword><keyword><style  face="normal" font="default" size="100%">Energy conservation</style></keyword><keyword><style  face="normal" font="default" size="100%">QoE</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">6868</style></volume><pages><style face="normal" font="default" size="100%">180-187</style></pages><isbn><style face="normal" font="default" size="100%">978-3-642-23446-0</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Due to the gradual and rapid increase in Information andCommunication Technology (ICT) industry, it is very important to introduce energy efficient techniques and infrastructures in large scale distributed systems. Content Distribution Networks (CDNs) are one of these popular systems which try to make the contents closer to the widely dispersed Internet users. A Content Distribution Network provides its services by using a number of surrogate servers geographicallydistributed in the web. Surrogate servers have the copies of the original contents belonging to the origin server, depending on their storage capacity.When a client requests for some particular contents from a surrogateserver, either this request can be fulfilled directly by it or in case of absence of the requested contents, surrogate servers cooperate with eachother or with the origin server. In this paper, our focus is on the surrogate servers utilization and using it as a parameter to conserve energy in CDNs while trying to maintain an acceptable Quality of Experience (QoE).&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Katsaros, Dimitrios</style></author><author><style face="normal" font="default" size="100%">Sidiropoulos, Antonis</style></author><author><style face="normal" font="default" size="100%">Manolopoulos, Yannis</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">CDNsim: A simulation tool for content distribution networks</style></title><secondary-title><style face="normal" font="default" size="100%">ACM Trans. Model. Comput. Simul.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">caching</style></keyword><keyword><style  face="normal" font="default" size="100%">Content Distribution Network</style></keyword><keyword><style  face="normal" font="default" size="100%">services</style></keyword><keyword><style  face="normal" font="default" size="100%">trace-driven simulation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><number><style face="normal" font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">20</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Content Distribution Networks (CDNs) have gained considerable attention in the past few years.As such, there is need for developing frameworks for carrying out CDN simulations. In this paper,we present a modeling and simulation framework for CDNs, called CDNsim. CDNsim hasbeen designated to provide a realistic simulation for CDNs, simulating the surrogate servers, theTCP/IP protocol and the main CDN functions. The main advantages of this tool are its high performance,its extensibility and its user interface which is used to configure its parameters. CDNsimprovides an automated environment for conducting experiments and extracting client, server andnetwork statistics. The purpose of CDNsim is to be used as a testbed for CDN evaluation andexperimentation. This is quite useful both for the research community (to experiment with newCDN data management techniques) and for CDN developers (to evaluate profits on prior certainCDN installations).&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Symeon Papadopoulos</style></author><author><style face="normal" font="default" size="100%">Christos Zigkolis</style></author><author><style face="normal" font="default" size="100%">Kapiris, Stefanos</style></author><author><style face="normal" font="default" size="100%">Yiannis Kompatsiaris</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Bimbo, Alberto Del</style></author><author><style face="normal" font="default" size="100%">Chang, Shih-Fu</style></author><author><style face="normal" font="default" size="100%">Smeulders, Arnold W. M.</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">ClustTour: city exploration by use of hybrid photo clustering</style></title><secondary-title><style face="normal" font="default" size="100%">ACM Multimedia</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Clustering</style></keyword><keyword><style  face="normal" font="default" size="100%">event and landmark detection</style></keyword><keyword><style  face="normal" font="default" size="100%">tagging</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pages><style face="normal" font="default" size="100%">1617-1620</style></pages><isbn><style face="normal" font="default" size="100%">978-1-60558-933-6</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;We present a technical demonstration of an online city explorationapplication that helps users identify interesting spotsin a city by use of photo clusters corresponding to landmarksand events. Our application, called ClustTour, is based onan efficient landmark and event detection scheme for taggedphoto collections. The proposed scheme relies on the combinationof a graph-based photo clustering algorithm, makinguse of both visual and tag information of photos, with acluster classification and merging module. ClustTour createsa map-based visualization of the identified photo clustersthat are classified in prominent categories and are filterableby time and tag. We believe that such an applicationcan greatly facilitate the task of knowing a city through itslandmarks and events. So far, the demo has been based on alarge photo dataset focused on Barcelona, and it is graduallyexpanding to contain photo clusters of several major cities ofEurope. Furthermore, an Android application is developedthat complements the web-based version of ClustTour.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Maria Giatsoglou</style></author><author><style face="normal" font="default" size="100%">Vassiliki A. Koutsonikola</style></author><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Christos Zigkolis</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Dynamic Code Generation for Cultural Content Management</style></title><secondary-title><style face="normal" font="default" size="100%">Panhellenic Conference on Informatics</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">21-24</style></pages><isbn><style face="normal" font="default" size="100%">978-1-4244-7838-5</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stampouli, Anastasia</style></author><author><style face="normal" font="default" size="100%">Giannakidou, Eirini</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Yoshikawa, Masatoshi</style></author><author><style face="normal" font="default" size="100%">Meng, Xiaofeng</style></author><author><style face="normal" font="default" size="100%">Yumoto, Takayuki</style></author><author><style face="normal" font="default" size="100%">Ma, Qiang</style></author><author><style face="normal" font="default" size="100%">Sun, Lifeng</style></author><author><style face="normal" font="default" size="100%">Watanabe, Chiemi</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Tag Disambiguation through Flickr and Wikipedia</style></title><secondary-title><style face="normal" font="default" size="100%">DASFAA Workshops</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">DBpedia project</style></keyword><keyword><style  face="normal" font="default" size="100%">flick</style></keyword><keyword><style  face="normal" font="default" size="100%">mashup</style></keyword><keyword><style  face="normal" font="default" size="100%">term disambiguation</style></keyword><keyword><style  face="normal" font="default" size="100%">Wikipedia</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">6193</style></volume><pages><style face="normal" font="default" size="100%">252-263</style></pages><isbn><style face="normal" font="default" size="100%">978-3-642-14588-9</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Given the popularity of social tagging systems and the limitationsthese systems have, due to lack of any structure, a common issue that arises involves the low retrieval quality in such systems due to ambiguities of certain terms. In this paper, an approach for improving the retrieval in these systems, in case of ambiguous terms, is presented that attempts to perform tag disambiguation and, at the same time, provide users with relevant content. The idea is based on a mashup that combines data and functionality of two major web 2.0 sites, namely Flickr and Wikipedia and aims at enhancing content retrieval for web users. A case study with the ambiguous notion â€śAppleâ€ť illustrates the value of the proposed approach.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bouzakis, K.-D.</style></author><author><style face="normal" font="default" size="100%">Andreadis, George</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Sarigiannidou, M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Automating the manufacturing process under a web based framework</style></title><secondary-title><style face="normal" font="default" size="100%">Advances in Engineering Software</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CAD/CAM</style></keyword><keyword><style  face="normal" font="default" size="100%">Manufacturing process</style></keyword><keyword><style  face="normal" font="default" size="100%">Process planning</style></keyword><keyword><style  face="normal" font="default" size="100%">SOAP</style></keyword><keyword><style  face="normal" font="default" size="100%">UDDI</style></keyword><keyword><style  face="normal" font="default" size="100%">Web services</style></keyword><keyword><style  face="normal" font="default" size="100%">xml</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><number><style face="normal" font="default" size="100%">9</style></number><volume><style face="normal" font="default" size="100%">40</style></volume><pages><style face="normal" font="default" size="100%">956-964</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The rapid evolution of the web has affected the way under which the manufacturing process is practised.In this paper, a web based framework â€“ independent from any specific CAD/CAM software â€“ is proposed,for employing electronic interaction between designers and manufacturers. In this context, designers andmanufacturers communicate for the manufacturing of a workpiece, under a platform-independent, easier,faster and more economical way. The proposed framework is implemented as a web service, wherethe Simple Object Access Protocol (SOAP) is used for the exchange of the necessary machined parts dataand the methodologies of UDDI (Universal Description Discovery and Integration) and WSDL (Web ServicesDescription Language) are introduced for providing directories and descriptions information.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Katsaros, Dimitrios</style></author><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Sidiropoulos, Antonis</style></author><author><style face="normal" font="default" size="100%">Manolopoulos, Yannis</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">CDNs Content Outsourcing via Generalized Communities</style></title><secondary-title><style face="normal" font="default" size="100%">IEEE Trans. Knowl. Data Eng.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">caching</style></keyword><keyword><style  face="normal" font="default" size="100%">content distribution networks</style></keyword><keyword><style  face="normal" font="default" size="100%">replication</style></keyword><keyword><style  face="normal" font="default" size="100%">social network analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">web communities</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">21</style></volume><pages><style face="normal" font="default" size="100%">137-151</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Content distribution networks (CDNs) balance costs and quality in services related to content delivery. Devising an efficientcontent outsourcing policy is crucial since, based on such policies, CDN providers can provide client-tailored content, improveperformance, and result in significant economical gains. Earlier content outsourcing approaches may often prove ineffective since theydrive prefetching decisions by assuming knowledge of content popularity statistics, which are not always available and are extremelyvolatile. This work addresses this issue, by proposing a novel self-adaptive technique under a CDN framework on which outsourcedcontent is identified with no a priori knowledge of (earlier) request statistics. This is employed by using a structure-based approachidentifying coherent clusters of â€ścorrelatedâ€ť Web server content objects, the so-called Web page communities. These communities arethe core outsourcing unit, and in this paper, a detailed simulation experimentation has shown that the proposed technique is robust andeffective in reducing user-perceived latency as compared with competing approaches, i.e., two communities-based approaches, Webcaching, and non-CDN.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Dikaiakos, Marios D.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Fortino, Giancarlo</style></author><author><style face="normal" font="default" size="100%">Mastroianni, Carlo</style></author><author><style face="normal" font="default" size="100%">Al-Mukaddim Khan Pathan</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Evaluating the utility of content delivery networks</style></title><secondary-title><style face="normal" font="default" size="100%">UPGRADE-CN</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CDN pricing</style></keyword><keyword><style  face="normal" font="default" size="100%">Content Delivery</style></keyword><keyword><style  face="normal" font="default" size="100%">network utility</style></keyword><keyword><style  face="normal" font="default" size="100%">networks</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pages><style face="normal" font="default" size="100%">11-20</style></pages><isbn><style face="normal" font="default" size="100%">978-1-60558-591-8</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Content Delivery Networks (CDNs) balance costs and qualityin services related to content delivery. This has urgedmany Web entrepreneurs to make contracts with CDNs. Inthe literature, a wide range of techniques has been developed,implemented and standardized for improving the performanceof CDNs. The ultimate goal of all the approachesis to improve the utility of CDN surrogate servers. In thispaper we define a metric which measures the utility of CDNsurrogate servers, called CDN utility. This metric capturesthe traffic activity in a CDN, expressing the usefulness ofsurrogate servers in terms of data circulation in the network.Through an extensive simulation testbed, we identifythe parameters that affect the CDN utility in such infrastructures.We evaluate the utility of surrogate servers undervarious parameters and provide insightful comments.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Moussiades, Lefteris</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Kefalas, Petros</style></author><author><style face="normal" font="default" size="100%">Stamatis, Demosthenes</style></author><author><style face="normal" font="default" size="100%">Douligeris, Christos</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Mining the Community Structure of a Web Site</style></title><secondary-title><style face="normal" font="default" size="100%">BCI</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">239-244</style></pages><isbn><style face="normal" font="default" size="100%">978-0-7695-3783-2</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Vassiliki A. Koutsonikola</style></author><author><style face="normal" font="default" size="100%">Petridou, Sophia G.</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Hacid, Hakim</style></author><author><style face="normal" font="default" size="100%">Benatallah, Boualem</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Bailey, James</style></author><author><style face="normal" font="default" size="100%">Maier, David</style></author><author><style face="normal" font="default" size="100%">Schewe, Klaus-Dieter</style></author><author><style face="normal" font="default" size="100%">Thalheim, Bernhard</style></author><author><style face="normal" font="default" size="100%">Wang, Xiaoyang Sean</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Correlating Time-Related Data Sources with Co-clustering</style></title><secondary-title><style face="normal" font="default" size="100%">WISE</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">5175</style></volume><pages><style face="normal" font="default" size="100%">264-279</style></pages><isbn><style face="normal" font="default" size="100%">978-3-540-85480-7</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;A huge amount of data is circulated and collected every dayon a regular time basis. Given a pair of such datasets, it might be possibleto reveal hidden dependencies between them since the presence of the onedataset elements may influence the elements of the other dataset and viceversa. Furthermore, the impact of these relations may last during a periodinstead of the time point of their co-occurrence. Mining such relationsunder those assumptions is a challenging problem. In this paper, we studytwo time-related datasets whose elements are bilaterally affected overtime. We employ a co-clustering approach to identify groups of similarelements on the basis of two distinct criteria: the direction and durationof their impact. The proposed approach is evaluated using time-relatednews and stockâ€™s market real datasets.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Thomos, Charilaos</style></author><author><style face="normal" font="default" size="100%">Andreadis, George</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Integrating Caching Techniques in CDNs using a Classification Approach</style></title><secondary-title><style face="normal" font="default" size="100%">IJBDCN</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><number><style face="normal" font="default" size="100%">4</style></number><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">1-12</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Content Delivery Networks (CDNs) provide an efficient support for serving â€śresourcehungryâ€ťapplications while minimizing the network impact of content delivery as well asshifting the traffic away from overloaded origin servers. However, their performance gain islimited since the storage space in CDNâ€™s servers is not used optimally. In order to managetheir storage capacity in an efficient way, we integrate caching techniques in CDNs. Thechallenge is to decide which objects would be devoted to caching so as the CDNâ€™s server maybe used both as a replicator and as a proxy server. In this paper we propose a nonlinear nonparametricmodel which classifies the CDNâ€™s server cache into two parts. Through a detailedsimulation environment, we show that the proposed technique can yield significant reductionin user-perceived latency as compared with other heuristic schemes.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sidiropoulos, Antonis</style></author><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Katsaros, Dimitrios</style></author><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Manolopoulos, Yannis</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Prefetching in Content Distribution Networks via Web Communities Identification and Outsourcing</style></title><secondary-title><style face="normal" font="default" size="100%">World Wide Web</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><number><style face="normal" font="default" size="100%">1</style></number><volume><style face="normal" font="default" size="100%">11</style></volume><pages><style face="normal" font="default" size="100%">39-70</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Vassiliki A. Koutsonikola</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Mpalasas, Antonios</style></author><author><style face="normal" font="default" size="100%">Valavanis, Michael</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">An, Aijun</style></author><author><style face="normal" font="default" size="100%">Matwin, Stan</style></author><author><style face="normal" font="default" size="100%">Ras, Zbigniew W.</style></author><author><style face="normal" font="default" size="100%">Slezak, Dominik</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">A Structure-Based Clustering on LDAP Directory Information</style></title><secondary-title><style face="normal" font="default" size="100%">ISMIS</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">4994</style></volume><pages><style face="normal" font="default" size="100%">121-130</style></pages><isbn><style face="normal" font="default" size="100%">978-3-540-68122-9</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;LDAP directories have rapidly emerged as the essentialframework for storing a wide range of heterogeneous information undervarious applications and services. Increasing amounts of informationare being stored in LDAP directories imposing the need for efficientdata organization and retrieval. In this paper, we propose the LPAIR&amp;amp; LMERGE (LP-LM) hierarchical agglomerative clustering algorithmfor improving LDAP data organization. LP-LM merges a pair of clustersat each step, considering the LD-vectors, which represent the entriesâ€™structure. The clustering-based LDAP data organization enhances LDAPserverâ€™s response times, under a specific query framework.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stoupa, Konstantina</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Clustering subjects in a credential-based access control framework</style></title><secondary-title><style face="normal" font="default" size="100%">Computers &amp; Security</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><number><style face="normal" font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">26</style></volume><pages><style face="normal" font="default" size="100%">120-129</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stoupa, Konstantina</style></author><author><style face="normal" font="default" size="100%">Simeoforidis, Zisis</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Levi, Albert</style></author><author><style face="normal" font="default" size="100%">Savas, Erkay</style></author><author><style face="normal" font="default" size="100%">Yenigün, Hüsnü</style></author><author><style face="normal" font="default" size="100%">Balcisoy, Selim</style></author><author><style face="normal" font="default" size="100%">Saygin, Yücel</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Credential-Based Policies Management in an Access Control Framework Protecting XML Resources</style></title><secondary-title><style face="normal" font="default" size="100%">ISCIS</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">4263</style></volume><pages><style face="normal" font="default" size="100%">603-612</style></pages><isbn><style face="normal" font="default" size="100%">3-540-47242-8</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;XML has been widely adopted for Web data representation undervarious applications (such as DBMSs, Digital Libraries etc). Therefore, accessto XML data sources has become a crucial issue. In this paper we introduce acredential-based access control framework for protecting XML resources. Underthis framework, we propose the use of access policy files containing policiesconcerning a specific credentials type. Moreover, we propose the reorganizationof the policies in these files based on their frequency of use (the morefrequently it is used the higher in the file it is placed). Our main goal is to improverequest servicing times. Several experiments have been conducted whichare carried out either on single request or on multiple requests base. The proposedframework is proven quite beneficial for protecting XML-based frameworkssuch as digital libraries or any other data resources whose format is expressedin XML.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Manolopoulos, Yannis</style></author><author><style face="normal" font="default" size="100%">Pokorny, Jaroslav</style></author><author><style face="normal" font="default" size="100%">Sellis, Timos K.</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Integrating Caching Techniques on a Content Distribution Network</style></title><secondary-title><style face="normal" font="default" size="100%">ADBIS</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">4152</style></volume><pages><style face="normal" font="default" size="100%">200-215</style></pages><isbn><style face="normal" font="default" size="100%">3-540-37899-5</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Web caching and replication tune capacity with performance and theyhave become essential components of the Web. In practice, caching and replicationtechniques have been applied in proxy servers and Content DistributionNetworks (CDNs) respectively. In this paper, we investigate the benefits of integratingcaching policies on a CDNâ€™ s infrastructure. Using a simulation testbed,our results indicate that there is much room for performance improvement interms of perceived latency, hit ratio and byte hit ratio. Moreover, we show thatthe combination of caching with replication fortifies CDNs against flash crowdevents.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stoupa, Konstantina</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">QoS-oriented negotiation in disk subsystems</style></title><secondary-title><style face="normal" font="default" size="100%">Data Knowl. Eng.</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><number><style face="normal" font="default" size="100%">2</style></number><volume><style face="normal" font="default" size="100%">58</style></volume><pages><style face="normal" font="default" size="100%">107-128</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Katsaros, Dimitrios</style></author><author><style face="normal" font="default" size="100%">Sidiropoulos, Antonis</style></author><author><style face="normal" font="default" size="100%">Manolopoulos, Yannis</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Barga, Roger S.</style></author><author><style face="normal" font="default" size="100%">Zhou, Xiaofang</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Replication Based on Objects Load under a Content Distribution Network</style></title><secondary-title><style face="normal" font="default" size="100%">ICDE Workshops</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">53</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Thomos, Charilaos</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Desai, Bipin C.</style></author><author><style face="normal" font="default" size="100%">Gupta, Shyam K.</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">A similarity based approach for integrated Web caching and content replication in CDNs</style></title><secondary-title><style face="normal" font="default" size="100%">IDEAS</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">239-242</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Web caching and content replication techniques emergedto solve performance problems related to the Web. We proposea generic non-parametric heuristic method that integratesboth techniques under a CDN. We provide experimentationshowing that our method outperforms the so farseparate implementations of Web caching and content replication.Moreover, we show that the performance improvementcompared with an existing algorithm is significant. Wetest all these techniques in a simulation environment undera flash crowd event and a workload of a typical lightweightedCDN operation.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Sidiropoulos, Eythimis</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">FRES-CAR: An Adaptive Cache Replacement Policy</style></title><secondary-title><style face="normal" font="default" size="100%">WIRI</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">74-81</style></pages><isbn><style face="normal" font="default" size="100%">0-7695-2414-1</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Caching Web objects has become a common practicetowards improving content delivery and usersâ€™ servicing.A Web caching framework is characterized by its cachereplacement policy, which identifies the objects (i.e. theelements on a Web page, which include text, graphics,and scripts) to be replaced in a cache upon a requestarrival. In this paper, we present a cache replacementalgorithm (so-called FRES-CAR), which identifies theobjects that should be evicted by considering togetherthree important criteria: objectâ€™s frequency, recency andsize. Experimentation under synthetic workloads hasshown that FRES-CAR achieves higher hit rates whencompared with the most popular and existing algorithms.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Stamos, Konstantinos</style></author><author><style face="normal" font="default" size="100%">Sidiropoulos, Antonis</style></author><author><style face="normal" font="default" size="100%">Katsaros, Dimitrios</style></author><author><style face="normal" font="default" size="100%">Manolopoulos, Yannis</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A Latency-Based Object Placement Approach in Content Distribution Networks</style></title><secondary-title><style face="normal" font="default" size="100%">LA-WEB</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE Computer Society</style></publisher><pages><style face="normal" font="default" size="100%">140-147</style></pages><isbn><style face="normal" font="default" size="100%">0-7695-2471-0</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>5</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pallis, George</style></author><author><style face="normal" font="default" size="100%">Stoupa, Konstantina</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Khosrow-Pour, Mehdi</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Storage and Access Control Issues for XML Documents</style></title><secondary-title><style face="normal" font="default" size="100%">Encyclopedia of Information Science and Technology (V)</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">Idea Group</style></publisher><pages><style face="normal" font="default" size="100%">2616-2621</style></pages><isbn><style face="normal" font="default" size="100%">1-59140-553-X</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hammiche, Samira</style></author><author><style face="normal" font="default" size="100%">Benbernou, Salima</style></author><author><style face="normal" font="default" size="100%">Hacid, Mohand-Said</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Chen, Shu-Ching</style></author><author><style face="normal" font="default" size="100%">Shyu, Mei-Ling</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Semantic retrieval of multimedia data</style></title><secondary-title><style face="normal" font="default" size="100%">MMDB</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Approximation Ontologies</style></keyword><keyword><style  face="normal" font="default" size="100%">MPEG-7</style></keyword><keyword><style  face="normal" font="default" size="100%">Multimedia Data</style></keyword><keyword><style  face="normal" font="default" size="100%">Tree embedding</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><publisher><style face="normal" font="default" size="100%">ACM</style></publisher><pages><style face="normal" font="default" size="100%">36-44</style></pages><isbn><style face="normal" font="default" size="100%">1-58113-975-6</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;This paper deals with the problem of finding multimediadata that fulfill the requirements of user queries. We assumeboth the user query and the multimedia data are expressedby MPEG-7 standard. The MPEG-7 formalism lacks thesemantics and reasoning support in many ways. For example,the search of the implicit data can not be achieved,due to its description based on XML schema. We propose aframework for querying multimedia data based on a tree embeddingapproximation algorithm, combining the MPEG-7standard and an ontology&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stoupa, Konstantina</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Li, Fang</style></author><author><style face="normal" font="default" size="100%">Andreadis, George</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Web-based delegation using XML</style></title><secondary-title><style face="normal" font="default" size="100%">SMC (6)</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Delegation</style></keyword><keyword><style  face="normal" font="default" size="100%">XML access control</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE</style></publisher><pages><style face="normal" font="default" size="100%">5189-5194</style></pages><isbn><style face="normal" font="default" size="100%">0-7803-8566-7</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Existing access control mechanisms should beextended in order to authorize external (and possiblyunknown) clients, when entering distributedenvironments. This paper proposes the structure andissuing of appropriate authorization certificate to supportthe delegation process under a role-based access controlenvironment. The proposed processes aim to enhanceaccessing automation and to avoid (centraladministrator) bottlenecks (in cases of altering anauthorization or a policy). The delegation requests andthe certificates are expressed according to the XMLsyntax for enhancing the interoperability of thedelegation processes, which is highlighted in a step-bystepalgorithmic fashion using flowcharts.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stoupa, Konstantina</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Li, Fang</style></author><author><style face="normal" font="default" size="100%">Tsoukalas, Ioannis</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Lindner, Wolfgang</style></author><author><style face="normal" font="default" size="100%">Mesiti, Marco</style></author><author><style face="normal" font="default" size="100%">Türker, Can</style></author><author><style face="normal" font="default" size="100%">Tzitzikas, Yannis</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">XML-Based Revocation and Delegation in a Distributed Environment</style></title><secondary-title><style face="normal" font="default" size="100%">EDBT Workshops</style></secondary-title><tertiary-title><style face="normal" font="default" size="100%">Lecture Notes in Computer Science</style></tertiary-title></titles><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer</style></publisher><volume><style face="normal" font="default" size="100%">3268</style></volume><pages><style face="normal" font="default" size="100%">299-308</style></pages><isbn><style face="normal" font="default" size="100%">3-540-23305-9</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The rapid increase on the circulation of data over the web has highlightedthe need for distributed storage of Internet-accessible information due tothe rapid increase on the circulation of data over the web. Thus, access controlmechanisms should also be distributed in order to protect them effectively. A recentidea in the access control theory is the delegation and revocation of rights,i.e. the passing over of one clients rights to the other and vice versa. Here, wepropose an XML-based distributed delegation module which can be integratedinto a distributed role-based access control mechanism protecting networks. Theidea of X.509v3 certificates is used for the transfer of authorization informationreferring to a client. The modules are XML-based and all of the associated datastructures are expressed through Document Type Definitions (DTDs).&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Stoupa, Konstantina</style></author><author><style face="normal" font="default" size="100%">Athena Vakali</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">An XML-based language for access control specifications in an RBAC environment</style></title><secondary-title><style face="normal" font="default" size="100%">SMC</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Access control</style></keyword><keyword><style  face="normal" font="default" size="100%">Attribute Certificates</style></keyword><keyword><style  face="normal" font="default" size="100%">Role Based Access Control</style></keyword><keyword><style  face="normal" font="default" size="100%">XML-based language</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2003</style></year></dates><publisher><style face="normal" font="default" size="100%">IEEE</style></publisher><pages><style face="normal" font="default" size="100%">1717-1722</style></pages><isbn><style face="normal" font="default" size="100%">0-7803-7952-7</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Lately, Web-accessed resources havesuperceded the resources accessed by local or wide-areanetworks. Therefore, new mechanisms should beimplemented for protecting resources from unknownclients. Attribute Certificates is a quite new technologyoffering such functionality. Those certificates are issuedby Attribute Authorities validating the attributes of theowner of the certificate. Based on this technology anXML-based access control mechanism is introduced forprotecting any kind of resources (from both known andunknown clients). The proposed model is ultimately rolebasedsince both clients and protected resources areorganized into roles. Moreover, an XML-based languageis introduced to express roles, authorizations, delegationrules, hierarchies and certificates.&lt;/p&gt;
</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Athena Vakali</style></author><author><style face="normal" font="default" size="100%">Stupa, Constantina</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Hung, C. C.</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">A QoS based disk subsystem</style></title><secondary-title><style face="normal" font="default" size="100%">Computers and Their Applications</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><publisher><style face="normal" font="default" size="100%">ISCA</style></publisher><pages><style face="normal" font="default" size="100%">409-412</style></pages><isbn><style face="normal" font="default" size="100%">1-880843-37-4</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language></record></records></xml>