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Ara es mostren els items 270-289 de 403

    • Nature inspired meta-heuristics for grid scheduling: single and multi-objective optimization approaches 

      Abraham, Ajith; Liu, Hongbo; Grosan, Crina; Xhafa Xhafa, Fatos (Springer, 2008)
      Capítol de llibre
      Accés obert
      In this chapter, we review a few important concepts from Grid computing related to scheduling problems and their resolution using heuristic and meta-heuristic approaches. Scheduling problems are at the heart of any Grid-like ...

    • Network energy consumption in ad-hoc networks under different radio models 

      Yang, Tao; Barolli, Leonard; Ikeda, Makoto; Durresi, Arjan; Xhafa Xhafa, Fatos (Institute of Electrical and Electronics Engineers (IEEE), 2007)
      Text en actes de congrés
      Accés obert
      In this work, we consider the behavior of a wireless ad- hoc network under TwoRayGround and Shadowing radio models. By means of simulations, we analyze the performance of three routing protocols: AODV, DSR, and DSDV, and ...

    • New efficient chosen ciphertext secure Elgamal encryption schemes for secure cloud storage service 

      An Wang, Xu; Ma, Jianfeng; Xhafa Xhafa, Fatos; Qin, Baodong; Zhang, Mingwu (2017)
      Article
      Accés restringit per política de l'editorial
      Nowadays Cloud computation has become a commonplace information service paradigm for all actors in ICT field, from individuals to big corporates. In particular, Cloud platforms and data centres are being used each time ...

    • Node placement for Wireless Mesh Networks: analysis of WMN-GA system simulation results for different parameters and distributions 

      Barolli, Admir; Oda, Tetsuya; Ikeda, Makoto; Barolli, Leonard; Xhafa Xhafa, Fatos; Loia, Vincenzo (2015-12-01)
      Article
      Accés obert
      Wireless Mesh Networks (WMNs) are attracting a lot of attention from wireless network researchers. Node placement problems have been investigated for a long time in the optimization field due to numerous applications in ...

    • Node placement in Wireless Mesh Networks: a comparison study of WMN-SA and WMN-PSO simulation systems 

      Sakamoto, Shinji; Oda, Tetsuya; Ikeda, Makoto; Barolli, Leonard; Xhafa Xhafa, Fatos; Woungang, Isaac (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Text en actes de congrés
      Accés obert
      With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our ...

    • Non-transferable unidirectional proxy re-encryption scheme for secure social cloud storage sharing 

      Wang, Xu An; Xhafa Xhafa, Fatos; Hao, Wei; He, Wei (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Text en actes de congrés
      Accés obert
      Proxy re-encryption (PRE), introduced by Blaze et al. in 1998, allows a semi-trusted proxy with the re-encryption key to translatea ciphertext under the delegator into another ciphertext, which can be decrypted by the ...

    • 'NoSQL' and electronic patient record systems: opportunities and challenges 

      Moore, Philip R.; Qassem, Tarek; Xhafa Xhafa, Fatos (Institute of Electrical and Electronics Engineers (IEEE), 2014)
      Text en actes de congrés
      Accés obert
      Research into electronic health record systems can be traced back over four decades however the penetration of records which incorporate more than simply basic information into healthcare organizations is relatively limited. ...

    • On Berners-Lee computer, hints on navigability semantics and lack of referential integrity 

      Gabarró Vallès, Joaquim; Vallejo, Isabel; Xhafa Xhafa, Fatos (2005-03)
      Report de recerca
      Accés obert
      In this paper we deal with semantics issues related to the stability, navigability and extensibility of web applications. To this end, we define a web application as a deterministic labelled transition system in which ...

    • On parallel versus sequential approximation 

      Serna Iglesias, María José; Xhafa Xhafa, Fatos (1995-03)
      Report de recerca
      Accés obert
      In this paper we deal with the class NCX of NP Optimization problems that are approximable within constant ratio in NC. This class is the parallel counterpart of the class APX. Our main motivation here is to reduce the ...

    • On sharing and synchronizing groupware calendars under android platform 

      Xhafa Xhafa, Fatos; Palou, Daniel; Caballé Llobet, Santiago; Barolli, Leonard (Institute of Electrical and Electronics Engineers (IEEE), 2016)
      Text en actes de congrés
      Accés obert
      Sharing a calendar of tasks and events is a cornerstone in collaborative group work. Indeed, the individual work of the members of the group as well as the group work as a whole need the calendar to guide their activity ...

    • On the average complexity of some P-complete problems 

      Serna Iglesias, María José; Xhafa Xhafa, Fatos (1995-10)
      Report de recerca
      Accés obert
      We show that some P-complete problems can be solved efficiently in average NC. The probabilistic model we consider is the sample space of input instances with underlying distribution the uniform one. The parallel algorithms ...

    • On the depth of randomly generated circuits 

      Tsukiji, Tatsuie; Xhafa Xhafa, Fatos (1996-03-02)
      Report de recerca
      Accés obert
      This research is motivated by the Circuit Value Problem; this problem is well known to be inherently sequential. We consider Boolean Circuits with descriptions of length d that consist of gates with a fixed fan-in f and a ...

    • On the parallel approximability of some classes of quadratic programming 

      Serna Iglesias, María José; Xhafa Xhafa, Fatos (1996-01)
      Report de recerca
      Accés obert
      In this paper we analyze the parallel approximability of two special classes of Quadratic Programming. First, we consider Convex Quadratic Programming . We show that the problem of Approximating Convex Quadratic Programming ...

    • On the performance of Oracle Grid Engine Queuing System for computing intensive applications 

      Kolici, Vladi; Herrera, Albert; Xhafa Xhafa, Fatos (2014)
      Article
      Accés restringit per política de l'editorial
      In this paper we present some research results on computing intensive applications using modern high performance architectures and from the perspective of high computational needs. Computing intensive applications are an ...

    • OPoR: enabling proof of retrievability in cloud computing with resource-constrained devices 

      Li, Jin; Tan, xiao; Chen, Xiaofeng; Wong, Duncan; Xhafa Xhafa, Fatos (Institute of Electrical and Electronics Engineers (IEEE), 2015)
      Article
      Accés obert
      Cloud computing moves the application software and databases to the centralized large data centers, where the management of the data and services may not be fully trustworthy. In this work, we study the problem of ensuring ...

    • Optimisation problems and resolution methods in satellite scheduling and space-craft operation: a survey 

      Xhafa Xhafa, Fatos; Ip, Andrew W. H. (2021-09)
      Article
      Accés obert
      The fast development in the production of small, low-cost satellites is propelling an important increase in satellite mission planning and operations projects. Central to satellite mission planning is the resolution of ...

    • Optimization of giant component and number of covered users in Wireless Mesh Networks: a comparison study 

      Kolici, Vladi; Barolli, Leonard; Sakamoto, Shinji; Oda, Tetsuya; Xhafa Xhafa, Fatos; Uchida, Kazunori (2015)
      Text en actes de congrés
      Accés obert
      One of the key advantages of Wireless Mesh Networks (WMNs) is their importance for providing cost efficient broad band connectivity. There are issues for achieving the network connectivity and user coverage, which are ...

    • Optimization of task allocations in Cloud to Fog environment with application to Intelligent Transportation Systems 

      Xhafa Xhafa, Fatos; Aly, Alhassan; Juan, Angel A. (2021)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Fog and Edge computing are opening up new opportunities to implement novel features of mobility, edge intelligence and end-user support. The successful implementation and deployment of Fog layers, as part of Cloud-to-thi ...

    • Optimization of vehicular networks in smart cities: from agile optimization to learnheuristics and simheuristics 

      Peyman, Mohammad; Fluechter, Tristan; Panadero Martínez, Javier; Serrat Piè, Carles; Xhafa Xhafa, Fatos; Alejandro Juan, Angel (Multidisciplinary Digital Publishing Institute (MDPI), 2023-01-02)
      Article
      Accés obert
      Vehicular ad hoc networks (VANETs) are a fundamental component of intelligent transportation systems in smart cities. With the support of open and real-time data, these networks of inter-connected vehicles constitute an ...

    • P2P data replication and trustworthiness for a JXTA-Overlay P2P system using fuzzy logic 

      Spaho, Evjola; Barolli, Leonard; Xhafa Xhafa, Fatos; Biberaj, A.; Shurdi, O. (2013-01)
      Article
      Accés restringit per política de l'editorial
      P2P systems are very important for future distributed systems and applications. In such systems, the computational burden of the system can be distributed to peer nodes of the system. Therefore, in decentralized systems ...