Browsing Conference papers by Issue Date

Now showing items 21-40 of 85

  • Multimedia Search with Noisy Modalities: Fusion and Multistage Retrieval 

    Arampatzis, Avi; Chatzichristofis, Savvas A.; Zagoris, Konstantinos (ImageClef, Wikipedia Retrieval Task, 2010)
    We report our experiences from participating to the controlled experiment of the ImageCLEF 2010 Wikipedia Retrieval task. We built an experimental search engine which combines multilingual and multi-image search, employing ...

  • A privacy-preserving protocol for finding the nearest doctor in an emergency 

    Drosatos, Georgios; Efraimidis, Pavlos S. (2010-06)
    In this work, we define the Nearest Doctor Problem (NDP) for finding the closest doctor in case of an emergency and present a secure multi-party computation for solving it. The solution is based on a privacy-preserving ...

  • The TREC files: the (ground) truth is out there 

    Chatzichristofis, Savvas A.; Zagoris, Konstantinos; Arampatzis, Avi (Association for Computing Machinery (ACM), United States, 2011)
    Traditional tools for information retrieval (IR) evaluation, such as TREC’s trec_eval, have outdated command-line interfaces with many unused features, or ‘switches’, accumulated over the years. They are usually seen ...

  • Comparative Performance Evaluation of Image Descriptors Over IEEE 802.11b NoisyWireless Networks 

    Chatzistavros, Evaggelos; Chatzichristofis, Savvas A.; Stamatellos, Georgios; Zagoris, Konstantinos (IEEE (Computer Society), 2011)
    Abstract—In this paper we evaluate the image retrieval procedure over an IEEE 802.11b Ad Hoc network, operating in 2.4GHz, using IEEE Distributed Coordination Function CSMA/CA as the multiple access scheme. IEEE 802.11 ...

  • Bag-of-visual-words vs global image descriptors on two-stage multimodal retrieval 

    Zagoris, Konstantinos; Chatzichristofis, Savvas A.; Arampatzis, Avi (ACM SIGIR 2011, 2011)
    The Bag-Of-Visual-Words (BOVW) paradigm is fast becoming a popular image representation for Content-Based Image Retrieval (CBIR), mainly because of its better retrieval effectiveness over global feature representations ...

  • Video Summarization Using a Self-Growing and Self-Organized Neural Gas Network 

    Papadopoulos, Dim. P.; Papamarkos, Nikos (Springer, 2011)
    In this paper, a novel method to generate video summaries is proposed, which is allocated mainly for being applied to on-line videos. The novelty of this approach lies in the fact that the video summarization problem is ...

  • Fusion vs. Two-Stage for Multimodal Retrieval 

    Arampatzis, Avi; Zagoris, Konstantinos; Chatzichristofis, Savvas A. (Springer, 2011)
    We compare two methods for retrieval from multimodal collections. The first is a score-based fusion of results, retrieved visually and textually. The second is a two-stage method that visually re-ranks the top-K results ...

  • Enhancing Deniability against Query-Logs 

    Arampatzis, Avi; Efraimidis, Pavlos S.; Drosatos, George (Springer, 2011)
    We propose a method for search privacy on the Internet, focusing onenhancing plausible deniability against search engine query-logs. The method ap-proximates the target search results, without submitting the intended query ...

  • Mobility in WSNs for Critical Applications 

    Silva, Ricardo; Zinonos, Zinon; Sá Silva, Jorge; Vassiliou, Vasos (IEEE, 2011)
    Recent critical application sectors of sensor networks like military, health care, and industry require the use of mobile sensor nodes, something that poses unique challenges in aspects like handoff delay, packet loss, and ...

  • Inter-Mobility Support in Controlled 6LoWPAN Networks 

    Zinonos, Zinon; Vassiliou, Vasos (IEEE, 2011)
    The research and industrial community started to think of more complex application scenarios for wireless sensor networks, where the use of mobile sensor nodes is essential. The support of mobile sensor nodes in such ...

  • WSN Evaluation in Industrial Environments First results and lessons learned 

    Poettner, W.; Wolf, L.; Cecílio, José; Furtado, Pedro; Mendão Silva, Ricardo; Sá Silva, Jorge; Cardoso, Alberto; Brown, J.; Sreenan, C.; Klein, A.; Roedig, U.; Vassiliou, Vasos; Voigt, T.; Donovan, T. O.; He, Z.; Zinonos, Zinon; Carrilho de Sousa Gil, Paulo José (IEEE, 2011)
    The GINSENG project develops performance-controlled wireless sensor networks that can be used for time-critical applications in hostile environments such as industrial plant automation and control. GINSENG aims at integrating ...

  • Dynamic Topology Control for WSNs in Critical Environments 

    Zinonos, Zinon; Vassiliou, Vasos; Ioannou, Christiana; Koutroullos, Marios (IEEE, 2011)
    Plant automation and control are mission-critical applications and require timely and reliable data delivery, which is difficult to provide using a wireless technology. This is especially more difficult in industrial ...

  • Content Based Image Retrieval Using Visual-Words Distribution Entropy 

    Chatzichristofis, Savvas A.; Iakovidou, Chrysanthi; Boutalis, Yiannis (Springer, 2011)
    Bag-of-visual-words (BOVW) is a representation of images which is built using a large set of local features. To date, the experimental results presented in the literature have shown that this approach achieves high retrieval ...

  • Dynamic Two-Stage Image Retrieval from Large Multimodal Databases 

    Arampatzis, Avi; Zagoris, Konstantinos; Chatzichristofis, Savvas A. (Springer-Verlag, 2011)
    Content-based image retrieval (CBIR) with global features is notoriously noisy, especially for image queries with low percentages of relevant images in a collection. Moreover, CBIR typically ranks the whole collection, ...

  • Privacy-Preserving Statistical Analysis on Ubiquitous Health Data 

    Drosatos, George; Efraimidis, Pavlos S. (Electrical and Computer Engineering, Democritus University of Thrace, 2011)
    In this work, we consider ubiquitous health data generated from wearable sensors in a Ubiquitous Health Monitoring System (UHMS) and examine how these data can be used within privacy preserving distributed statistical ...

  • Privacy-Enhanced Management of Ubiquitous Health Monitoring Data 

    Drosatos, George; Efraimidis, Pavlos S. (PETRA, 2011-05-25)
    In this paper, we propose a new architecture for managing data in a Ubiquitous Health Monitoring System (UHMS). The purpose of this architecture is to enhance the privacy of patients and furthermore to decongest the Health ...

  • SFly: Swarm of Micro Flying Robots 

    Achtelik, Markus; Achtelik, Michael; Brunet, Yorick; Chli, Margarita; Chatzichristofis, Savvas A. (IEEE (Computer Society), 2012)
    The SFly project is an EU-funded project, with the goal to create a swarm of autonomous vision controlled micro aerial vehicles. The mission in mind is that a swarm of MAV’s autonomously maps out an unknown environmen ...

  • Privacy-Preserving Television Audience Measurement Using Smart TVs 

    Drosatos, George; Tasidou, Aimilia; Efraimidis, Pavlos S. (2012)
    Internet-enabled television systems, often referred to as Smart TVs, are a new development in television and home entertainment technologies. In this work, we propose a new, privacy-preserving, approach for Television ...

  • A privacy-preserving cloud computing system for creating participatory noise maps 

    Drosatos, George; Efraimidis, Pavlos S.; Athanasiadis, Ioannis N.; D’Hondt, Ellie; Stevens, Matthias (IEEE, 2012)
    Participatory sensing is a crowd-sourcing technique which relies both on active contribution of citizens and on their location and mobility patterns. As such, it is particularly vulnerable to privacy concerns, which may ...

  • Ελεγχόμενη πρόσβαση σε κλειστό χώρο με χρήση ηλεκτρονικού υπολογιστή 

    Stamatelatos, George; Drosatos, George (2012-04)
    Στα πλαίσια αυτής της δουλειάς υλοποιήσαμε μία πλατφόρμα για το άνοιγμα μιας πόρτας χρησιμοποιώντας σύγχρονες τεχνολογίες, όπως αναγνώριση δακτυλικού αποτυπώματος [1] και δικτυακής διαχείρισης. Εξηγούμε τον τρόπο με τον ...