Now showing items 1-20 of 32

    • Detection of compound structures using multiple hierarchical segmentations 

      Akcay H.G.; Aksoy, S. (IEEE Computer Society, 2014)
      In this paper, we present a method for automatic compound structure detection in high-resolution images. Given a query compound structure, our aim is to detect coherent regions with similar spatial arrangement and ...
    • Distributed block formation and layout for disk-based management of large-scale graphs 

      Yaşar, A.; Gedik, B.; Ferhatosmanoğlu, H. (Springer, 2017)
      We are witnessing an enormous growth in social networks as well as in the volume of data generated by them. An important portion of this data is in the form of graphs. In recent years, several graph processing and management ...
    • Document replication strategies for geographically distributed web search engines 

      Kayaaslan, E.; Cambazoglu, B. B.; Aykanat, C. (Elsevier Ltd., 2013)
      Large-scale web search engines are composed of multiple data centers that are geographically distant to each other. Typically, a user query is processed in a data center that is geographically close to the origin of the ...
    • Effective use of space for pivot-based metric indexing structures 

      Celik, C. (2008)
      Among the metric space indexing methods, AESA is known to produce the lowest query costs in terms of the number of distance computations. However, its quadratic construction cost and space consumption makes it infeasiblefor ...
    • Efficiency and effectiveness of query processing in cluster-based retrieval 

      Can, F.; Altingövde I.S.; Demir, E. (Elsevier, 2004)
      Our research shows that for large databases, without considerable additional storage overhead, cluster-based retrieval (CBR) can compete with the time efficiency and effectiveness of the inverted index-based full search ...
    • Efficient processing of category-restricted queries for web directories 

      Altingovde, I. S.; Can, F.; Ulusoy, Ö. (Springer, 2008)
      We show that a cluster-skipping inverted index (CS-IIS) is a practical and efficient file structure to support category-restricted queries for searching Web directories. The query processing strategy with CS-IIS improves ...
    • Energy-price-driven query processing in multi-center web search engines 

      Kayaaslan, E.; Cambazoglu, B. B.; Blanco, R.; Junqueira, F. P.; Aykanat, C. (2011)
      Concurrently processing thousands of web queries, each with a response time under a fraction of a second, necessitates maintaining and operating massive data centers. For large-scale web search engines, this translates ...
    • First large-scale information retrieval experiments on Turkish texts 

      Can, F.; Kocberber, S.; Balcik, E.; Kaynak, C.; Ocalan, H. C.; Vursavas, O. M. (2006)
      We present the results of the first large-scale Turkish information retrieval experiments performed on a TREC-like test collection. The test bed, which has been created for this study, contains 95.5 million words, 408,305 ...
    • A five-level static cache architecture for web search engines 

      Ozcan, R.; Altingovde, I. S.; Cambazoglu, B. B.; Junqueira, F. P.; Ulusoy, Ö. (Elsevier Ltd, 2012)
      Caching is a crucial performance component of large-scale web search engines, as it greatly helps reducing average query response times and query processing workloads on backend search clusters. In this paper, we describe ...
    • HandVR: a hand-gesture-based interface to a video retrieval system 

      Genç, S.; Baştan M.; Güdükbay U.; Atalay, V.; Ulusoy, Ö. (Springer U K, 2015)
      Using one’s hands in human–computer interaction increases both the effectiveness of computer usage and the speed of interaction. One way of accomplishing this goal is to utilize computer vision techniques to develop ...
    • Implications of non-volatile memory as primary storage for database management systems 

      Mustafa, N. U.; Armejach, A.; Ozturk, O.; Cristal, A.; Unsal, O. S. (Institute of Electrical and Electronics Engineers, 2017)
      Traditional Database Management System (DBMS) software relies on hard disks for storing relational data. Hard disks are cheap, persistent, and offer huge storage capacities. However, data retrieval latency for hard disks ...
    • Incremental cluster-based retrieval using compressed cluster-skipping inverted files 

      Altingovde, I. S.; Demir, E.; Can, F.; Ulusoy, Ö. (Association for Computing Machinery, 2008-06)
      We propose a unique cluster-based retrieval (CBR) strategy using a new cluster-skipping inverted file for improving query processing efficiency. The new inverted file incorporates cluster membership and centroid information ...
    • Information retrieval on Turkish texts 

      Can, F.; Kocberber, S.; Balcik, E.; Kaynak, C.; Ocalan, H. C.; Vursavas, O. M. (John Wiley & Sons, Inc., 2008-02)
      In this study, we investigate information retrieval (IR) on Turkish texts using a large-scale test collection that contains 408,305 documents and 72 ad hoc queries. We examine the effects of several stemming options and ...
    • Lexical cohesion and term proximity in document ranking 

      Vechtomova, O.; Karamuftuoglu, M. (Elsevier Ltd, 2008-07)
      We demonstrate effective new methods of document ranking based on lexical cohesive relationships between query terms. The proposed methods rely solely on the lexical relationships between original query terms, and do not ...
    • Mobile image search using multi-query images 

      Calisir F.; Bastan, M.; Gudukbay, U.; Ulusoy O. (Institute of Electrical and Electronics Engineers Inc., 2015)
      Recent advances in mobile device technology have turned the mobile phones into powerfull devices with high resolution cameras and fast processing capabilities. Having more user interaction potential compared to regular ...
    • Models and algorithms for parallel text retrieval 

      Cambazoğlu, Berkant Barla (Bilkent University, 2006)
      In the last decade, search engines became an integral part of our lives. The current state-of-the-art in search engine technology relies on parallel text retrieval. Basically, a parallel text retrieval system is composed ...
    • Natural language querying for video databases 

      Erozel, G.; Cicekli, N. K.; Cicekli, I. (Elsevier Inc., 2008-06-15)
      The video databases have become popular in various areas due to the recent advances in technology. Video archive systems need user-friendly interfaces to retrieve video frames. In this paper, a user interface based on ...
    • New formulations for the hop-constrained minimum spanning tree problem via Sherali and Driscoll's tightened Miller-Tucker-Zemlin constraints 

      Akgün I. (2010)
      Given an undirected network with positive edge costs and a natural number p, the hop-constrained minimum spanning tree problem (HMST) is the problem of finding a spanning tree with minimum total cost such that each path ...
    • Ottoman archives explorer: a retrieval system for digital Ottoman archives 

      Yalniz, I. Z.; Altingovde, I. S.; Güdükbay U.; Ulusoy, Ö. (Association for Computing Machinery, 2009-12)
      This article presents Ottoman Archives Explorer, a Content-Based Retrieval (CBR) system based on character recognition for printed and handwritten historical documents. Several methods for character segmentation and ...
    • Parallel text retrieval on temporally versioned document collections 

      Gür, Özlem (Bilkent University, 2008)
      In recent years, as the access to the Internet is getting easier and cheaper, the amount and the rate of change of the online data presented to the Internet users are increasing at an astonishing rate. This ever-changing ...