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Displaying 1-33 out of 33 total
LDAP: Framework, Practices, and Trends
Found in: IEEE Internet Computing
By Vassiliki Koutsonikola, Athena Vakali
Issue Date:September 2004
pp. 66-72
Directory services facilitate access to information organized under a variety of frameworks and applications. The Lightweight Directory Access Protocol is a promising technology that provides access to directory information using a data structure similar t...
Dissimilarity Features in Recommender Systems
Found in: 2013 IEEE 13th International Conference on Data Mining Workshops (ICDMW)
By Christos Zigkolis,Savvas Karagiannidis,Athena Vakali
Issue Date:December 2013
pp. 825-832
In the context of recommenders, providing suitable suggestions requires an effective content analysis where information for items, in the form of features, can play a significant role. Many recommenders suffer from the absence of indicative features capabl...
Micro-blogging Content Analysis via Emotionally-Driven Clustering
Found in: 2013 Humaine Association Conference on Affective Computing and Intelligent Interaction (ACII)
By Despoina Chatzakou,Vassiliki Koutsonikola,Athena Vakali,Konstantinos Kafetsios
Issue Date:September 2013
pp. 375-380
Microblogging has become commonplace and created new methods of communication, contributing significantly to information sharing. This holds since microblogging focuses on sharing content while building social relations among people who share the same inte...
Capturing Social Data Evolution Using Graph Clustering
Found in: IEEE Internet Computing
By Maria Giatsoglou,Athena Vakali
Issue Date:January 2013
pp. 74-79
The fast and unpredictable evolution of social data poses challenges for capturing user activities and complex associations. Evolving social graph clustering promises to uncover the dynamics of latent user and content patterns. This Web extra overviews evo...
Social Web Mashups Full Completion via Frequent Sequence Mining
Found in: Services, IEEE Congress on
By Abderrahmane Maaradji,Hakim Hacid,Ryan Skraba,Athena Vakali
Issue Date:July 2011
pp. 9-16
In this paper we address the problem of Web Mashups full completion which consists of predicting the most suitable set of (combined) services that successfully meet the goals of an end-user Mashup, given the current service (or composition of services) ini...
Towards a User-Aware Virtual Museum
Found in: Games and Virtual Worlds for Serious Applications, Conference in
By Christos Zigkolis, Vassiliki Koutsonikola, Despoina Chatzakou, Savvas Karagiannidis, Maria Giatsoglou, Andreas Kosmatopoulos, Athena Vakali
Issue Date:May 2011
pp. 228-235
The exploration of cultural heritage through well-designed virtual worlds has met an increase in popularity within the last decade. More and more well-known museums around the globe have started to spend funds in order to build systems with which users can...
Cluster-Based Landmark and Event Detection for Tagged Photo Collections
Found in: IEEE Multimedia
By Symeon Papadopoulos, Christos Zigkolis, Yiannis Kompatsiaris, Athena Vakali
Issue Date:January 2011
pp. 52-63
<p>An image analysis scheme can automate the detection of landmarks and events in large image collections, significantly improving the content-consumption experience. The Web extra includes a video that illustrates a new approach for mining landmarks...
Cloud Computing: Distributed Internet Computing for IT and Scientific Research
Found in: IEEE Internet Computing
By Marios D. Dikaiakos, Dimitrios Katsaros, Pankaj Mehra, George Pallis, Athena Vakali
Issue Date:September 2009
pp. 10-13
Cloud computing is location agnostic and provides dynamically scalable and virtualized resources as services over the Internet. Here, the authors provide broad introductory definitions to cloud computing concepts. Articles in this special issue investigate...
SEMSOC: SEMantic, SOcial and Content-Based Clustering in Multimedia Collaborative Tagging Systems
Found in: International Conference on Semantic Computing
By Eirini Giannakidou, Ioannis Kompatsiaris, Athena Vakali
Issue Date:August 2008
pp. 128-135
A huge amount of data and metadata emerges from Web 2.0 applications which have transformed the Web to a mass social interaction and collaboration medium. Collaborative Tagging Systems is a typical, popular and promising Web 2.0 application and despite its...
Co-Clustering Tags and Social Data Sources
Found in: Web-Age Information Management, International Conference on
By Eirini Giannakidou, Vassiliki Koutsonikola, Athena Vakali, Yiannis Kompatsiaris
Issue Date:July 2008
pp. 317-324
Under social tagging systems, a typical Web 2.0 application, users label digital data sources by using freely chosen textual descriptions (tags). Poor retrieval in the aforementioned systems remains a major problem mostly due to questionable tag validity a...
CDNs Content Outsourcing via Generalized Communities
Found in: IEEE Transactions on Knowledge and Data Engineering
By Dimitrios Katsaros, George Pallis, Konstantinos Stamos, Athena Vakali, Antonis Sidiropoulos, Yannis Manolopoulos
Issue Date:January 2009
pp. 137-151
Content Distribution Networks (CDNs) balance costs and quality in services related to content delivery. Devising an efficient content outsourcing policy is crucial since, based on such policies, CDN providers can provide client-tailored content, improve pe...
Time-Aware Web Users' Clustering
Found in: IEEE Transactions on Knowledge and Data Engineering
By Sophia G. Petridou, Vassiliki A. Koutsonikola, Athena I. Vakali, Georgios I. Papadimitriou
Issue Date:May 2008
pp. 653-667
Web users clustering is a crucial task for mining information related to users needs and preferences. Up to now, popular clustering approaches build clusters based on usage patterns derived from users' page preferences. This paper emphasizes the need to di...
A similarity based approach for integrated Web caching and content replication in CDNs
Found in: Database Engineering and Applications Symposium, International
By Konstantinos Stamos, George Pallis, Charilaos Thomos, Athena Vakali
Issue Date:December 2006
pp. 239-242
Web caching and content replication techniques emerged to solve performance problems related to the Web. We propose a generic non-parametric heuristic method that integrates both techniques under a CDN. We provide experimentation showing that our method ou...
Replication Based on Objects Load under a Content Distribution Network
Found in: Data Engineering Workshops, 22nd International Conference on
By George Pallis, Konstantinos Stamos, Athena Vakali, Dimitrios Katsaros, Antonis Sidiropoulos, Yannis Manolopoulos
Issue Date:April 2006
pp. 53
Users tend to use the Internet for ?resource-hungry? applications (which involve content such as video, audio on-demand and distributed data) and at the same time, more and more applications (such as e-commerce, elearning etc.) are relying on the Web. In t...
Intrusion Detection in RBAC-administered Databases
Found in: Computer Security Applications Conference, Annual
By Elisa Bertino, Ashish Kamra, Evimaria Terzi, Athena Vakali
Issue Date:December 2005
pp. 170-182
A considerable effort has been recently devoted to the development of Database Management Systems (DBMS) which guarantee high assurance security and privacy. An important component of any strong security solution is represented by intrusion detection (ID) ...
A Logic Based Approach for the Multimedia Data Representation and Retrieval
Found in: Multimedia, International Symposium on
By Samira Hammiche, Salima Benbernou, Athena Vakali
Issue Date:December 2005
pp. 241-248
<p>Nowadays, the amount of multimedia data is increasing rapidly, and hence, there is an increasing need for efficient methods to manage the multimedia content. This paper proposes a framework for the description and retrieval of multimedia data. The...
A Latency-Based Object Placement Approach in Content Distribution Networks
Found in: Web Congress, Latin American
By George Pallis, Athena Vakali, Konstantinos Stamos, Antonis Sidiropoulos, Dimitrios Katsaros, Yannis Manolopoulos
Issue Date:November 2005
pp. 140-147
Content Distribution Networks (CDNs) are increasingly being used to disseminate data in today's Internet. The growing interest in CDNs is motivated by a common problem across disciplines: how does one reduce the load on the origin server and the traffic on...
XML Document Indexes: A Classification
Found in: IEEE Internet Computing
By Barbara Catania, Anna Maddalena, Athena Vakali
Issue Date:September 2005
pp. 64-71
XML's increasing diffusion makes efficient XML query processing and indexing all the more critical. Given the semistructured nature of XML documents, however, general query processing techniques won't work. Researchers have proposed several specialized ind...
FRES-CAR: An Adaptive Cache Replacement Policy
Found in: Challenges in Web Information Retrieval and Integration, International Workshop on
By George Pallis, Athena Vakali, Eythimis Sidiropoulos
Issue Date:April 2005
pp. 74-81
<p>Caching Web objects has become a common practice towards improving content delivery and users? servicing. A Web caching framework is characterized by its cache replacement policy, which identifies the objects (i.e. the elements on a Web page, whic...
XML Data Stores: Emerging Practices
Found in: IEEE Internet Computing
By Athena Vakali, Barbara Catania, Anna Maddalena
Issue Date:March 2005
pp. 62-69
Because XML is rapidly becoming the Internet standard for data representation and exchange, efficient XML document storage has become a core data management issue. Most early XML storage practices rely on conventional database management systems. However, ...
Guest Editors' Introduction: Web Engineering--The Evolution of New Technologies
Found in: Computing in Science and Engineering
By Athena I. Vakali, Georgios I. Papadimitriou
Issue Date:July 2004
pp. 10-11
The Web is now the most popular environment for circulating information as network-accessible data; the exponential growth in this information?s dissemination is contributing to the evolution of research topics in the field of Web engineering. This issue o...
Content Delivery Networks: Status and Trends
Found in: IEEE Internet Computing
By Athena Vakali, George Pallis
Issue Date:November 2003
pp. 68-74
<p>CDNs improve network performance and offer fast and reliable applications and services by distributing content to cache servers located close to users.</p>
A Web-Based Evolutionary Model for Internet Data Caching
Found in: Database and Expert Systems Applications, International Workshop on
By Athena Vakali
Issue Date:September 1999
pp. 650
Caching is a standard solution to the problem of insufficient bandwidth caused by the rapid increase of information circulation across the Internet. Cache consistency mechanisms are a crucial component of each cache scheme influencing the cache usefulness ...
Requirements and architecture design principles for a smart city experiment with sensor and social networks integration
Found in: Proceedings of the 17th Panhellenic Conference on Informatics (PCI '13)
By Athena Vakali, Christos Samaras, Despoina Chatzakou, Lefteris Angelis, Maria Giatsoglou
Issue Date:September 2013
pp. 327-334
Smart city infrastructures offer unique testbeds ground for innovative experimentation and services offering. Sensors networks in cities with integrated social networks activities can improve people-centric services, while improving infrastructures setting...
Using social annotations to enhance document representation for personalized search
Found in: Proceedings of the 36th international ACM SIGIR conference on Research and development in information retrieval (SIGIR '13)
By Athena Vakali, Hakim Hacid, Mohamed Reda BOUADJENEK, Mokrane Bouzeghoub
Issue Date:July 2013
pp. 1049-1052
In this paper, we present a contribution to IR modeling. We propose an approach that computes on the fly, a Personalized Social Document Representation (PSDR) of each document per user based on his social activities. The PSDRs are used to rank documents wi...
Evolving social data mining and affective analysis methodologies, framework and applications
Found in: Proceedings of the 16th International Database Engineering & Applications Sysmposium (IDEAS '12)
By Athena Vakali
Issue Date:August 2012
pp. 1-7
Social networks drive todays opinions and content diffusion. Large scale, distributed and unpredictable social data streams are produced and such evolving data production offers the ground for the data mining and analysis tasks. Such social data streams em...
A Clustering-Driven LDAP Framework
Found in: ACM Transactions on the Web (TWEB)
By Athena Vakali, Vassiliki Koutsonikola, Vassiliki Koutsonikola
Issue Date:July 2011
pp. 1-34
LDAP directories have proliferated as the appropriate storage framework for various and heterogeneous data sources, operating under a wide range of applications and services. Due to the increased amount and heterogeneity of the LDAP data, there is a requir...
ClustTour: city exploration by use of hybrid photo clustering
Found in: Proceedings of the international conference on Multimedia (MM '10)
By Athena Vakali, Christos Zigkolis, Stefanos Kapiris, Symeon Papadopoulos, Yiannis Kompatsiaris
Issue Date:October 2010
pp. 1617-1620
We present a technical demonstration of an online city exploration application that helps users identify interesting spots in a city by use of photo clusters corresponding to landmarks and events. Our application, called ClustTour, is based on an efficient...
Hydra: an open framework for virtual-fusion of recommendation filters
Found in: Proceedings of the fourth ACM conference on Recommender systems (RecSys '10)
By Athena Vakali, Christos Zigkolis, Savvas Karagiannidis, Stefanos Antaris
Issue Date:September 2010
pp. 229-232
Today's web commercial applications demand more powerful recommendation systems due to the rapid increase in the number of both consumers and available products. Searching for the best algorithm with the highest accuracy and realistic complexity is, most o...
Next generation content networks: trends and challenges
Found in: Proceedings of the 4th edition of the UPGRADE-CN workshop on Use of P2P, GRID and agents for the development of content networks (UPGRADE-CN '09)
By Athena Vakali, Carlo Mastroianni, Giancarlo Fortino, Mukaddim Pathan
Issue Date:June 2009
pp. 1-2
Content Delivery Networks (CDNs) [1] have emerged to overcome the inherent limitations of the Internet in terms of user perceived Quality of Service (QoS) when accessing Web content. They offer infrastructure and mechanisms to deliver content and services ...
Evaluating the utility of content delivery networks
Found in: Proceedings of the 4th edition of the UPGRADE-CN workshop on Use of P2P, GRID and agents for the development of content networks (UPGRADE-CN '09)
By Athena Vakali, George Pallis, Konstantinos Stamos, Marios D. Dikaiakos
Issue Date:June 2009
pp. 1-2
Content Delivery Networks (CDNs) balance costs and quality in services related to content delivery. This has urged many Web entrepreneurs to make contracts with CDNs. In the literature, a wide range of techniques has been developed, implemented and standar...
Insight and perspectives for content delivery networks
Found in: Communications of the ACM
By Athena Vakali, George Pallis
Issue Date:January 2006
pp. 101-106
Striking a balance between the costs for Web content providers and the quality of service for Web customers.
Semantic retrieval of multimedia data
Found in: Proceedings of the 2nd ACM international workshop on Multimedia databases (MMDB '04)
By Athena Vakali, Mohand-Said Hacid, Salima Benbernou, Samira Hammiche
Issue Date:November 2004
pp. 36-44
This paper deals with the problem of finding multimedia data that fulfill the requirements of user queries. We assume both the user query and the multimedia data are expressed by MPEG-7 standard. The MPEG-7 formalism lacks the semantics and reasoning suppo...