Now showing items 1-20 of 26

  • Blind adaptive channel estimation in OFDM Systems 

    Doukopoulos, X. G.; Moustakides, G. V. (2006)
    We consider the problem of blind channel estimation in zero padding OFDM systems, and propose blind adaptive algorithms in order to identify the impulse response of the multipath channel. In particular, we develop RLS and ...
  • Categorical range queries in large databases 

    Nanopoulos, A.; Bozanis, P. (2003)
    In this paper, we introduce the categorical (a.k.a. chromatic) range queries (CRQs) in the context of large, disk-resident data sets, motivated by the fact, that CRQs are conceptually simple and emerge often in DBMSs. On ...
  • Classification tree based protein structure distances for testing sequence-structure correlation 

    Zintzaras, E. (2008)
    A methodology for testing the correlation between the sequence and structure distances of proteins is proposed. Structure distances were derived by applying a forward growing classification tree algorithm on defined ...
  • DDEMA: A data driven environment for multiphysics applications 

    Michopoulos, J.; Tsompanopoulou, P.; Houstis, E.; Rice, J.; Farhat, C.; Lesoinne, M.; Lechenault, F. (2003)
    In this paper we present the design of a multidisciplined problem solving environment (MPSE) for supporting an efficient prediction capability for the response of multiscale interdisciplinary continuous interacting systems. ...
  • A dissipative particle dynamics study of flow in periodically grooved nanochannels 

    Kasiteropoulou, D.; Karakasidis, T. E.; Liakopoulos, A. (2012)
    The effect of periodic rectangular wall roughness on planar nanochannel flow is investigated by dissipative particle dynamics simulation. The wall protrusion length is varied, and its effect on the flow is examined. Analysis ...
  • Dynamic frequency management in 802.11-based multi-radio wireless networks 

    Athanasiou, G.; Tassiulas, L. (2014)
    Efficient channel selection is essential in 802.11 mesh deployments, for minimising contention and interference among co-channel devices and thereby supporting a plurality of quality of service (QoS)-sensitive applications. ...
  • An efficient Recommendation System based on the Optimal Stopping Theory 

    Kolomvatsos, K.; Anagnostopoulos, C.; Hadjiefthymiades, S. (2014)
    A Recommendation System (RS) aims to deliver meaningful recommendations to users for items (e.g., music and books), which are of high interest to them. We consider an RS which directly communicates with a set of providers ...
  • Energy-efficient distributed clustering in wireless sensor networks 

    Dimokas, N.; Katsaros, D.; Manolopoulos, Y. (2010)
    The deployment of wireless sensor networks in many application areas requires self-organization of the network nodes into clusters. Clustering is a network management technique, since it creates a hierarchical structure ...
  • Enhancing Differential Evolution Utilizing Proximity-Based Mutation Operators 

    Epitropakis, M. G.; Tasoulis, D. K.; Pavlidis, N. G.; Plagianakos, V. P.; Vrahatis, M. N. (2011)
    Differential evolution is a very popular optimization algorithm and considerable research has been devoted to the development of efficient search operators. Motivated by the different manner in which various search operators ...
  • Exact Knowledge Hiding through Database Extension 

    Gkoulalas-Divanis, A.; Verykios, V. S. (2009)
    In this paper, we propose a novel, exact border-based approach that provides an optimal solution for the hiding of sensitive frequent item sets by 1) minimally extending the original database by a synthetically generated ...
  • Explicit integration of bounding surface model for the analysis of earthquake soil liquefaction 

    Andrianopoulos, K. I.; Papadimitriou, A. G.; Bouckovalas, G. D. (2010)
    This paper presents a new plasticity model developed for the simulation of monotonic and cyclic loading of non-cohesive soils and its implementation to the commercial finite-difference code FLAC, using its User-Defined-Model ...
  • An extension of labeling techniques for finding shortest path trees 

    Ziliaskopoulos, A. K.; Mandanas, F. D.; Mahmassani, H. S. (2009)
    Label setting techniques are all based on Dijkstra's condition of always scanning the node with the minimum label, which guarantees that each node will be scanned exactly once; while this condition is sufficient it is not ...
  • Global Systems for Mobile Position Tracking Using Kalman and Lainiotis Filters 

    Assimakis, N.; Adam, M. (2014)
    We present two time invariant models for Global Systems for Mobile (GSM) position tracking, which describe the movement in x-axis and y-axis simultaneously or separately. We present the time invariant filters as well as ...
  • Hiding sensitive knowledge without side effects 

    Gkoulalas-Divanis, A.; Verykios, V. S. (2009)
    Sensitive knowledge hiding in large transactional databases is one of the major goals of privacy preserving data mining. However, it is only recently that researchers were able to identify exact solutions for the hiding ...
  • Lainiotis filter, golden section and Fibonacci sequence 

    Assimakis, N.; Adam, M.; Triantafillou, C. (2013)
    The relation between the discrete time Lainiotis filter on the one side and the golden section and the Fibonacci sequence on the other is established. As far as the random walk system is concerned, the relation between the ...
  • Monte Carlo dosimetric evaluation of high energy vs low energy photon beams in low density tissues 

    Tsiakalos, M. F.; Stathakis, S.; Plataniotis, G. A.; Kappas, C.; Theodorou, K. (2006)
    Background and purpose: Low megavoltage photon beams are often the treatment choice in radiotherapy when low density heterogeneities are involved, because higher energies show some undesirable dosimetric effects. This work ...
  • Nonrecursive solution for the discrete algebraic Riccati equation and X plus A*X-1 A = L 

    Adam, M.; Assimakis, N. (2015)
    In this paper, we present two new algebraic algorithms for the solution of the discrete algebraic Riccati equation. The first algorithm requires the nonsingularity of the transition matrix and is based on the solution of ...
  • On a data-driven environment for multiphysics applications 

    Michopoulos, J.; Tsompanopoulou, P.; Houstis, E.; Farhat, C.; Lesoinne, M.; Rice, J.; Joshi, A. (2005)
    The combination of the recent advances in computational and distributed sensor network technologies provide a unique opportunity for focused efforts on high confidence modelling and simulation of multiphysics systems. ...
  • ON ITERATIVE SOLUTION FOR LINEAR COMPLEMENTARITY PROBLEM WITH AN H+-MATRIX 

    Hadjidimos, A.; Lapidakis, M.; Tzoumas, M. (2012)
    The numerous applications of the linear complementarity problem (LCP) in, e.g., the solution of linear and convex quadratic programming, free boundary value problems of fluid mechanics, and moving boundary value problems ...
  • On minimizing the resource consumption of cloud applications using process migrations 

    Tziritas, N.; Khan, S. U.; Xu, C. Z.; Loukopoulos, T.; Lalis, S. (2013)
    According to the pay-per-use model adopted in clouds, the more resources an application running in a cloud computing environment consumes, the greater the amount of money the owner of the corresponding application will be ...