Browsing by Subject "Search results"
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Item Open Access Adaptive time-to-live strategies for query result caching in web search engines(2012) Alıcı, Sadiye; Altıngövde, I. Ş.; Rıfat, Özcan; Cambazoğlu, B. Barla; Ulusoy, ÖzgürAn 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 with a fixed time-to-live (TTL) value in order to bound the staleness of search results presented to the users, potentially as part of a more complex cache refresh or invalidation mechanism. In this paper, we propose techniques where the TTL values are set in an adaptive manner, on a per-query basis. Our results show that the proposed techniques reduce the fraction of stale results served by the cache and also decrease the fraction of redundant query evaluations on the search engine backend compared to a strategy using a fixed TTL value for all queries. © 2012 Springer-Verlag Berlin Heidelberg.Item Open Access Characterizing web search queries that match very few or no results(ACM, 2012-11) Altıngövde, İ. Ş.; Blanco, R.; Cambazoğlu, B. B.; Özcan, Rıfat; Sarıgil, Erdem; Ulusoy, ÖzgürDespite 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 characterization of such queries based on an analysis of a real-life query log. Our experimental setup allows us to characterize the queries with few/no results and compare the mechanisms employed by the major search engines in handling them.Item Open Access A new approach to search result clustering and labeling(Springer, Berlin, Heidelberg, 2011) Türel, Anıl; Can, FazlıSearch engines present query results as a long ordered list of web snippets divided into several pages. Post-processing of retrieval results for easier access of desired information is an important research problem. In this paper, we present a novel search result clustering approach to split the long list of documents returned by search engines into meaningfully grouped and labeled clusters. Our method emphasizes clustering quality by using cover coefficient-based and sequential k-means clustering algorithms. A cluster labeling method based on term weighting is also introduced for reflecting cluster contents. In addition, we present a new metric that employs precision and recall to assess the success of cluster labeling. We adopt a comparative strategy to derive the relative performance of the proposed method with respect to two prominent search result clustering methods: Suffix Tree Clustering and Lingo. Experimental results in the publicly available AMBIENT and ODP-239 datasets show that our method can successfully achieve both clustering and labeling tasks. © 2011 Springer-Verlag Berlin Heidelberg.Item Open Access A path-quality-aware peer-to-peer file sharing protocol for mobile ad-hoc networks: Wi-Share(IEEE, 2009-09) Karasabun, Efe; Ertemür, Doğuş; Sarıyıldız, Seyhun; Tekkalmaz, Metin; Körpeoğlu, İbrahimPeer-to-peer networks are rather well-studied and currently there are numerous systems based on peer-to-peer principles running on the Internet. On the other hand peer-to-peer networks for mobile ad-hoc networks have attracted attention only in the recent years. In this paper, we propose a novel peer-to-peer file sharing system particularly designed for mobile ad-hoc networks. The proposed system, namely Wi-Share, has both network and application layer aspects enabling efficient search and download of the shared files. Wi-Share uses reactive routing for the search operation combined with source discovery and uses the routing tables constructed during the search operation for the download operation. In order to increase the overall efficiency of the file sharing in the network, Wi-Share applies techniques to reduce the required traffic and to increase efficient parallelism of the download operation. These techniques include filtering search results, preferring the higher quality routing paths, using partitioned download scheme and allowing the nodes that have joined to the network recently to contribute to the ongoing downloads. Wi-Share is implemented to work on mobile computers and the results of several experiments are also presented in the paper. © 2009 IEEE.