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Πλοήγηση ανά Θέμα "Computational complexity"

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    • Approximation caching and routing algorithms for massive mobile data delivery 

      Poularakis, K.; Iosifidis, G.; Tassiulas, L. (2013)
      Small cells constitute a promising solution for managing the mobile data growth that has overwhelmed network operators. Local caching of popular content items at the small cell base stations has been proposed in order to ...

    • Black virus decontamination of synchronous ring networks by initially scattered mobile agents 

      Giachoudis N., Kokkou M., Markou E. (2020)
      We study the Black Virus Decontamination problem in ring topologies for initially scattered mobile agents. In this problem a number of mobile agents operate in a network where one of its nodes u is hostile (contaminated) ...

    • Blind channel estimation for downlink CDMA systems 

      Doukopoulos, X. G.; Moustakides, G. V. (2003)
      The problem of channel estimation in code-division multiple-access (CDMA) systems is considered. Using only the spreading code of the user of interest, a technique is proposed to identify the impulse response of the multipath ...

    • Computation of the adjoint matrix 

      Akritas, A.; Malaschonok, G. (2006)
      The best method for computing the adjoint matrix of an order n matrix in an arbitrary commutative ring requires O(nβ+1/3 log n log log n) operations, provided that the complexity of the algorithm for multiplying two matrices ...

    • Dangerous graphs 

      Markou E., Shi W. (2019)
      Anomalies and faults are inevitable in computer networks, today more than ever before. This is due to the large scale and dynamic nature of the networks used to process big data and to the ever-increasing number of ad-hoc ...

    • A Fast Timing Separation of Events Algorithm for Concurrent Systems 

      Aimoniotis P., Xiromeritis N., Sotiriou C. (2019)
      In this work, we present a fast, polynomial time implementation of the Timing Separation of Events (TSE) Algorithm, with complexity O(E × (V+E). TSE computation is a fundamental problem in the analysis of event-driven, ...

    • The geodesic broadcast scheme for wireless ad hoc networks 

      Katsaros, D.; Manolopoulos, Y. (2006)
      Broadcasting is an effective means for disseminating information in wireless ad hoc networks. In this paper we propose a novel distributed broadcasting protocol in wireless ad hoc networks, which is based on an highly ...

    • Implementing replica placements: Feasibility and cost minimization 

      Loukopoulos, T.; Tziritas, N.; Lampsas, P.; Lalis, S. (2007)
      Given two replication schemes Xold and Xnew, the Replica Transfer Scheduling Problem (RTSP) aims at reaching Xnew, starting from Xold, with minimal implementation cost. In this paper we generalize the problem description ...

    • Joint multiuser downlink beamforming and admission control: A semidefinite relaxation approach 

      Matskani, E.; Sidiropoulos, N. D.; Luo, Z. Q.; Tassiulas, L. (2007)
      Multiuser downlink beamforming under quality of service (QoS) constraints has attracted considerable interest in recent years, because it is particularly appealing from a network operator's perspective (e.g., UMTS, 802.16e). ...

    • Layered backpressure scheduling for delay reduction in ad hoc networks 

      Maglaras, L. A.; Katsaros, D. (2011)
      Packet scheduling in wireless ad hoc networks is a fundamental problem for ad hoc networking. Backpressure scheduling is a solid and throughput optimal policy for such networks, but suffers from increased delays. In this ...

    • Linear Time S-Component Extraction for General Petri Nets 

      Sakellariou A., Valiantzas D., Sotiriou C., Xiromeritis N., Sketopoulos N. (2019)
      In this work, we present a linear time, S-component extraction algorithm capable of handling strongly connected, General Petri Nets. Most prior works have focused exclusively on Free-Choice or Extended Free-Choice Nets. ...

    • Mapping and optimization of the AVS video decoder on a high performance chip multiprocessor 

      Krommydas, K.; Tsoublekas, G.; Antonopoulos, C. D.; Bellas, N. (2010)
      Modern multimedia workloads provide increased levels of quality and compression efficiency at the expense of substantially increased computational complexity. It is important to leverage the off-the-shelf emerging multi-core ...

    • Massively parallel programming models used as hardware description languages: The OpenCL case 

      Owaida, M.; Bellas, N.; Antonopoulos, C. D.; Daloukas, K.; Antoniadis, C. (2011)
      The problem of automatically generating hardware modules from high level application representations has been at the forefront of EDA research during the last few years. In this paper, we introduce a methodology to ...

    • Multiobjective optimum path algorithm for passenger pretrip planning in multimodal transportation networks 

      Aifadopoulou, G.; Ziliaskopoulos, A.; Chrisohoou, E. (2007)
      This paper aims to present a multiobjective optimum path algorithm for passenger pretrip planning in multimodal transportation networks. The process of identifying the feasible paths accounts for the delays caused by the ...

    • National survey of morbidity and risk factors (EMENO): Protocol for a health examination survey representative of the adult Greek population 

      Touloumi G., Karakatsani A., Karakosta A., Sofianopoulou E., Koustenis P., Gavana M., Alamanos Y., Kantzanou M., Konstantakopoulos G., Chryssochoou X., Benos A., Vantarakis A., Hadjichristodoulou C., Chlouverakis G., Trypsianis G., Voulgari P.V., Makrilakis K., Liatis S., Stergiou G. (2019)
      Background: Main causes of death in Greece are cardiovascular diseases (CVDs), malignant neoplasms, respiratory diseases, and road traffic crashes. To assess the population health status, monitor health systems, and adjust ...

    • Node clustering in wireless sensor networks by considering structural characteristics of the network graph 

      Dimokas, N.; Katsaros, D.; Manolopoulos, Y. (2007)
      The deployment of wireless sensor networks in many application areas, e.g., aggregation services, requires self-organization of the network nodes into clusters. Quite a lot of node clustering techniques have appeared in ...

    • Optimization algorithms for system integration 

      Papadimitriou, C.; Ntotsios, E. (2008)
      This work outlines the optimization algorithms involved in integrating system analysis and measured data collected from a network of sensors. The integration is required for structural health monitoring problems arising ...

    • Stathis zachos at 70! 

      Bakali E., Cheilaris P., Fotakis D., Fürer M., Koutras C.D., Markou E., Nomikos C., Pagourtzis A., Papadimitriou C.H., Papaspyrou N.S., Potika K. (2017)
      This year we are celebrating the 70th birthday of Stathis! We take this chance to recall some of his remarkable contributions to Computer Science. © Springer International Publishing AG 2017.

    • A study of indices useful for the assessment of diagnostic markers in non-parametric ROC curve analysis 

      Alonso R., Nakas C.T., Carmen Pardo M. (2020)
      Diagnostic markers that discriminate between two classes, such as healthy and diseased subjects in medical diagnostics, are useful in virtually all fields of applied research. ROC curve analysis is widely used in order to ...

    • Using multicast transfers in the replica migration problem: Formulation and scheduling heuristics 

      Tziritas, N.; Loukopoulos, T.; Lampsas, P.; Lalis, S. (2009)
      Performing replica migrations in the minimum possible time, also called the Replica Migration Problem (RMP), is crucial in distributed systems using replication. In this paper we tackle RMP when multicast transfers are ...