Now showing items 1-20 of 45

    • Adaptive time-to-live strategies for query result caching in web search engines 

      Alıcı, Sadiye; Altıngövde, I. Ş.; Rıfat, Özcan; Cambazoğlu, B. Barla; Ulusoy, Özgür (2012)
      An important research problem that has recently started to receive attention is the freshness issue in search engine result caches. In the current techniques in literature, the cached search result pages are associated ...
    • Atatürk'ün el yazmalarının işlenmesi 

      Soysal, Talha; Adıgüzel Hande; Öktem, Alp; Haman, Alican; Can, Ethem Fatih; Duygulu, Pınar; Kalpaklı, Mehmet (IEEE, 2010-04)
      Bu çalımada Atatürk'ün el yazmalarının etkin ve kolay eriimini salayabilecek kelime tabanlı bir arama sisteminin ilk aaması olarak sayısallatırılmı belgelerin ön ilemesi ve satır ve kelimelere bölütlenmesi konusunda çalımalar ...
    • Authorship attribution: performance of various features and classification methods 

      Bozkurt, İlker Nadi; Bağlıoğlu, Özgür; Uyar, Erkan (IEEE, 2007-11)
      Authorship attribution is the process of determining the writer of a document. In literature, there are lots of classification techniques conducted in this process. In this paper we explore information retrieval methods ...
    • Automatic performance evaluation of Web search engines 

      Can, F.; Nuray, R.; Sevdik, A. B. (Elsevier, 2004)
      Measuring the information retrieval effectiveness of World Wide Web search engines is costly because of human relevance judgments involved. However, both for business enterprises and people it is important to know the most ...
    • Automatic Ranking of Retrieval Systems in Imperfect Environments 

      Nuray, Rabia; Can, Fazlı (ACM, 2003-07-08)
      The empirical investigation of the effectiveness of information retrieval (IR) systems requires a test collection, a set of query topics, and a set of relevance judgments made by human assessors for each query. Previous ...
    • Characterizing web search queries that match very few or no results 

      Altıngövde, İ. Ş.; Blanco, R.; Cambazoğlu, B. B.; Özcan, Rıfat; Sarıgil, Erdem; Ulusoy, Özgür (ACM, 2012-11)
      Despite the continuous efforts to improve the web search quality, a non-negligible fraction of user queries end up with very few or even no matching results in leading web search engines. In this work, we provide a detailed ...
    • Cost-aware strategies for query result caching in Web search engines 

      Ozcan, R.; Altingovde, I. S.; Ulusoy, O. (Association for Computing Machinery, 2011)
      Search engines and large-scale IR systems need to cache query results for efficiency and scalability purposes. Static and dynamic caching techniques (as well as their combinations) are employed to effectively cache query ...
    • Diversity and novelty in information retrieval 

      Santos, R. L. T.; Castells, P.; Altıngövde, I. S.; Can, Fazlı (ACM, 2013-07-08)
      This tutorial aims to provide a unifying account of current research on diversity and novelty in different IR domains, namely, in the context of search engines, recommender sys- tems, and data streams.
    • Energy-price-driven query processing in multi-center web search engines 

      Kayaaslan, Enver; Cambazoglu, B. B.; Blanco, R.; Junqueira, F. P.; Aykanat, Cevdet (IEEE, 2011-07)
      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 ...
    • Evolution of web search results within years 

      Altıngövde, İsmail Şengör; Özcan, Rıfat; Ulusoy, Özgür (ACM, 2011-07)
      We provide a first large-scale analysis of the evolution of query results obtained from a real search engine at two distant points in time, namely, in 2007 and 2010, for a set of 630,000 real queries.
    • Exploiting navigational queries for result presentation and caching in Web search engines 

      Ozcan, R.; Altingovde, I. S.; Ulusoy, O. (John Wiley & Sons, Inc., 2011)
      Caching of query results is an important mechanism for efficiency and scalability of web search engines. Query results are cached and presented in terms of pages, which typically include 10 results each. In navigational ...
    • Exploiting query views for static index pruning in web search engines 

      Altıngövde, İsmail Şengör; Özcan, Rıfat; Ulusoy, Özgür (ACM, 2009-11)
      We propose incorporating query views in a number of static pruning strategies, namely term-centric, document-centric and access-based approaches. These query-view based strategies considerably outperform their counterparts ...
    • A financial cost metric for result caching 

      Sazoğlu, Fethi Burak; Cambazoğlu, B. B.; Özcan, R.; Altıngövde, I. S.; Ulusoy, Özgür (ACM, 2013-07-08)
      Web search engines cache results of frequent and/or recent queries. Result caching strategies can be evaluated using different metrics, hit rate being the most well-known. Recent works take the processing overhead of queries ...
    • Görsel arama sonuçlarının çoklu örnekle öğrenme yöntemiyle yeniden sıralanması 

      Şener, Fadime; Cinbiş, N. I.; Duygulu-Şahin, Pınar (IEEE, 2012-04)
      Bu çalışmada, çoklu öğrenme yöntemi ile metin tabanlı arama motorlarından elde edilen görsel sorgu sonuçlarını iyileştirmek için geliştirilmiş olan, zayıf denetimli öğrenen bir yöntem sunulmaktadır. Bu yöntemde arama ...
    • How k-12 students search for learning?: analysis of an educational search engine log 

      Usta, Arif; Altıngövde, İsmail Şengör; Vidinli, İ. B.; Özcan, R.; Ulusoy, Özgür (ACM, 2014-07)
      In this study, we analyze an educational search engine log for shedding light on K-12 students' search behavior in a learning environment. We specially focus on query, session, user and click characteristics and compare ...
    • Hypergraph-theoretic partitioning models for parallel web crawling 

      Türk, Ata; Cambazoğlu, B. Barla; Aykanat, Cevdet (Springer, London, 2012)
      Parallel web crawling is an important technique employed by large-scale search engines for content acquisition. A commonly used inter-processor coordination scheme in parallel crawling systems is the link exchange scheme, ...
    • Improved DST cryptanalysis of IDEA 

      Ayaz, Eyüp Serdar; Selçuk, Ali Aydın (Springer, 2006-08)
      In this paper, we show how the Demirci-Selcuk-Ture attack, which is currently the deepest penetrating attack on the IDEA block cipher, can be improved significantly in performance. The improvements presented reduce the ...
    • Incorporating the surfing behavior of web users into PageRank 

      Ashyralyyev, Shatlyk; Cambazoğlu, B. B.; Aykanat, Cevdet (ACM, 2013-10-11)
      In large-scale commercial web search engines, estimating the importance of a web page is a crucial ingredient in ranking web search results. So far, to assess the importance of web pages, two different types of feedback ...
    • Integrated segmentation and recognition of connected Ottoman script 

      Yalniz, I. Z.; Altingovde, I. S.; Güdükbay, Uğur; Ulusoy, Özgür (S P I E - International Society for Optical Engineering, 2009-11)
      We propose a novel context-sensitive segmentation and recognition method for connected letters in Ottoman script. This method first extracts a set of segments from a connected script and determines the candidate letters ...
    • Keyframe labeling technique for surveillance event classification 

      Şaykol, E.; Baştan M.; Güdükbay, Uğur; Ulusoy, Özgür (S P I E - International Society for Optical Engineering, 2010)
      The huge amount of video data generated by surveillance systems necessitates the use of automatic tools for their efficient analysis, indexing, and retrieval. Automated access to the semantic content of surveillance videos ...