Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Conference Object
    Citation - Scopus: 2
    Hiding Sensitive Predictive Frequent Itemsets
    (International Association of Engineers, 2011) Yıldız, Barış; Ergenç, Belgin
    In this work, we propose an itemset hiding algorithm with four versions that use different heuristics in selecting the item in itemset and the transaction for distortion. The main strengths of itemset hiding algorithm can be stated as i) it works without pre-mining so privacy breech caused by revealing frequent itemsets in advance is prevented and efficiency is increased, ii) base algorithm (Matrix-Apriori) works without candidate generation so efficiency is increased, iii) sanitized database and frequent itemsets of this database are given as outputs so no post-mining is required and iv) simple heuristics like the length of the pattern and the frequency of the item in the pattern are used for selecting the item for distortion. We compare versions of our itemset hiding algorithm by their side effects, runtimes and distortion on original database.
  • Conference Object
    Citation - WoS: 6
    Citation - Scopus: 11
    Dynamically Adaptive Partition-Based Data Distribution Management
    (Institute of Electrical and Electronics Engineers Inc., 2005) Kumova, Bora İsmail
    Performance and scalability of distributed simulations depends primarily on the effectiveness of the employed data distribution management (DDM) algorithm, which aims at reducing the overall computational and messaging effort on the shared data to a necessary minimum. Existing DDM approaches, which are variations and combinations of two basic techniques, namely region-based and grid-based techniques, perform purely in the presence of load differences. We introduce the partition-based technique that allows for variable-size partitioning shared data. Based on this technique, a novel DDM algorithm is introduced that is dynamically adaptive to cluster formations in the shared data as well as in the physical location of the simulation objects. Since the re-distribution is sensitive to inter-relationships between shared data and simulation objects, a balanced constellation has the additional advantage to be of minimal messaging effort. Furthermore, dynamic system scalability is facilitated, as bottlenecks are avoided.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 7
    The Adaptive Channel Estimation for Stbc-Ofdm Systems
    (İstanbul Üniversitesi, 2005) Özbek, Berna; Yılmaz, Reyat
    In this paper, we propose adaptive channel estimation methods based on LMS and RLS for orthogonal STBC-OFDM systems with three transmit antennas. The performance of the proposed algorithms is obtained in the frequency selective channels using Hiperlan/2 characteristics.
  • Conference Object
    Rank Kestirim Yöntemi Kullanarak Svd Tabanlı Gürültü Filtreleme
    (Institute of Electrical and Electronics Engineers Inc., 2004) Çek, Mehmet Emre; Savacı, Ferit Acar
    In this paper, an algorithm which performs the singular values decomposition of a noisy matrix has been presented in order to make noise reduction by rank estimation of the noise free data matrix. In this study the rank estimation methodis done by finding ratios of among all consecutive singular values and selecting the maximum of these ratios as the noise threshold.