All of DSpace

Browsing by Subject "Trees (mathematics)"

Now showing items 1-20 of 24

    • A-tree: Distributed indexing of multidimensional data for cloud computing environments 

      Papadopoulos, A.; Katsaros, D. (2011)
      Efficient querying of huge volumes of multidimensional data stored in cloud computing systems has become a necessity, due to the widespread of cloud storage facilities. With clouds getting larger and available data growing ...

    • Bulk insertions into xBR+-trees 

      Roumelis G., Vassilakopoulos M., Corral A., Manolopoulos Y. (2017)
      Bulk insertion refers to the process of updating an existing index by inserting a large batch of new data, treating the items of this batch as a whole and not by inserting these items one-by-one. Bulk insertion is related ...

    • Bulk-loading and bulk-insertion algorithms for xBR +-trees in Solid State Drives 

      Roumelis G., Fevgas A., Vassilakopoulos M., Corral A., Bozanis P., Manolopoulos Y. (2019)
      Spatial indexes are important in spatial databases for efficient execution of queries involving spatial constraints. The xBR +-tree is a balanced, disk-resident, Quadtree-based index for point data, which is very efficient ...

    • Bulk-loading xBR+-trees 

      Roumelis G., Vassilakopoulos M., Corral A., Manolopoulos Y. (2016)
      Spatial indexes are important in spatial databases for efficient execution of queries involving spatial constraints. The xBR+-tree is a balanced disk-resident quadtree-based index structure for point data, which is very ...

    • Distributed Algorithms for the Operator Placement Problem 

      Tziritas N., Loukopoulos T., Khan S.U., Xu C.-Z. (2015)
      Operator placement plays a key role in reducing the aggregate network overhead within a wireless sensor network (WSN) to extend battery life and the longevity of the network. Consequently, optimal algorithms for the operator ...

    • Distributed skip air index for smart broadcasting in intelligent transportation systems 

      Maglaras, L. A.; Katsaros, D. (2012)
      Wireless data broadcast received a lot of attention from industries and academia in recent years. In any form of a push-based broadcast, access latency and tuning time are vital issues, and in order to address the tradeoff ...

    • An efficient algorithm for bulk-loading xBR+-trees 

      Roumelis G., Vassilakopoulos M., Corral A., Manolopoulos Y. (2018)
      A major part of the interface to a database is made up of the queries that can be addressed to this database and answered (processed) in an efficient way, contributing to the quality of the developed software. Efficiently ...

    • An efficient flash-aware spatial index for points 

      Carniel A.C., Roumelis G., Ciferri R.R., Vassilakopoulos M., Corral A., Ciferri C.D.deA. (2018)
      Spatial database systems often employ spatial indices to speed up the processing of spatial queries. In addition, modern spatial database applications are interested in exploiting the positive characteristics of flash-based ...

    • Efficient query processing on large spatial databases: A performance study 

      Roumelis G., Vassilakopoulos M., Corral A., Manolopoulos Y. (2017)
      Processing of spatial queries has been studied extensively in the literature. In most cases, it is accomplished by indexing spatial data using spatial access methods. Spatial indexes, such as those based on the Quadtree, ...

    • Examining travelers "optimal strategies" in transit trip choices, applying a classification tree approach on transit quality of service indicators 

      Tsami, M. T.; Nathanail, E. G. (2014)
      According to Spiess and Florian (1989) [1], at each transfer point passengers may shape the "optimal" for them strategy taking into account minimum generalized travel cost. The generalized cost of trip choices is formulated ...

    • Farm management information system for fruit orchards 

      Tsiropoulos Z., Fountas S. (2015)
      Fruticulture faces increasing market pressures that threaten its long-term viability. In the light of the real need to practically improve the environmental performance, to increase yield and to optimize product quality ...

    • Flower spatial variability in an apple orchard 

      Aggelopoulou, A. D.; Bochtis, D.; Koutsostathis, A.; Fountas, S.; Gemtos, T. A.; Nanos, G. D. (2009)
      Precision pomology is the application of site-specific management into orchards. Orchards produce high value crops and the application of site-specific management has high potential. Finding plant or soil characteristics ...

    • Guidance Provision for Increasing Quality of Service of Public Transport 

      Tsami M., Nathanail E. (2017)
      Travellers formulate their optimal strategyto follow for their trip, every time they may shift to another mode. Trip generalized cost is perceived based on quality of service aspects and type of traveller. One of the most ...

    • Investigation on Performance, Power, Area Trade-Offs using Deterministic and Monte-Carlo Process Variation Aware Synthesis Flows 

      Blias N., Lilitsis I., Simoglou S., Bakas E., Sotiriou C. (2022)
      Process variation has proven to be one of the higher impacting factors in modern Application-Specific Integrated Circuit (ASIC) flows Quality of Results (QoR). On the one hand, the excessive MOSFET shrinking, in combination ...

    • New plane-sweep algorithms for distance-based join queries in spatial databases 

      Roumelis G., Corral A., Vassilakopoulos M., Manolopoulos Y. (2016)
      Efficient and effective processing of the distance-based join query (DJQ) is of great importance in spatial databases due to the wide area of applications that may address such queries (mapping, urban planning, transportation ...

    • On Improving Constrained Single and Group Operator Placement Using Evictions in Big Data Environments 

      Tziritas N., Loukopoulos T., Khan S.U., Xu C.-Z., Zomaya A.Y. (2016)
      With an ever increasing amount of data generated by scientific experiments, social networks and mobile as well as wireless sensor networks, reducing resource consumption by big data applications becomes of paramount ...

    • Online Inter-Datacenter Service Migrations 

      Tziritas N., Khan S.U., Loukopoulos T., Lalis S., Xu C.-Z., Li K., Zomaya A.Y. (2020)
      Service migration between datacenters can reduce the network overhead within a cloud infrastructure; thereby, also improving the quality of service for the clients. Most of the algorithms in the literature assume that the ...

    • Optimal cooperative content placement algorithms in hierarchical cache topologies 

      Poularakis, K.; Tassiulas, L. (2012)
      The tremendous growth in the use of the World Wide Web and the expansion of Video On Demand and IPTV services increase the bandwidth demands, enforcing the creation of congestion in Internet's links and the experience of ...

    • Parallel processing of spatial batch-queries using xBR + -trees in solid-state drives 

      Roumelis G., Velentzas P., Vassilakopoulos M., Corral A., Fevgas A., Manolopoulos Y. (2020)
      Efficient query processing in spatial databases is of vital importance for numerous modern applications. In most cases, such processing is accomplished by taking advantage of spatial indexes. The xBR +-tree is an index for ...

    • Pathway analysis using xgboost classification in biomedical data 

      Dimitrakopoulos G.N., Vrahatis A.G., Sgarbas K., Plagianakos V. (2018)
      Given the fact that our biological existence is rooted in a complex system within our cells with thousands of interactions among genes and metabolites, research community in biological and medical fields have shifted their ...