Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

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

Browse

Filters

2004 - 200972010 - 20143

Settings

Subject: search.filters.subject.AlgorithmsWoS Q: search.filters.wosQuartile.N/A

Search Results

Now showing 1 - 10 of 10
  • Article
    Citation - WoS: 30
    Machine Learning Methods for Microrna Gene Prediction
    (Humana Press, 2014) Saçar, Müşerref Duygu; Allmer, Jens
    MicroRNAs (miRNAs) are single-stranded, small, noncoding RNAs of about 22 nucleotides in length, which control gene expression at the posttranscriptional level through translational inhibition, degradation, adenylation, or destabilization of their target mRNAs. Although hundreds of miRNAs have been identified in various species, many more may still remain unknown. Therefore, discovery of new miRNA genes is an important step for understanding miRNA-mediated posttranscriptional regulation mechanisms. It seems that biological approaches to identify miRNA genes might be limited in their ability to detect rare miRNAs and are further limited to the tissues examined and the developmental stage of the organism under examination. These limitations have led to the development of sophisticated computational approaches attempting to identify possible miRNAs in silico. In this chapter, we discuss computational problems in miRNA prediction studies and review some of the many machine learning methods that have been tried to address the issues.
  • Conference Object
    Citation - Scopus: 5
    Performance Comparison of Combined Collaborative Filtering Algorithms for Recommender Systems
    (Institute of Electrical and Electronics Engineers Inc., 2012) Tapucu, Dilek; Kasap, Seda; Tekbacak, Fatih
    Recommender systems have a goal to make personalized recommendations by using filtering algorithms. Collaborative filtering (CF) is one of the most popular techniques for recommender systems. As usual, huge number of the datasets on the Internet increase the amount of time to work on data. This challenge enforces people to improve better algorithms for processing data with user preferences and recommending the most appropriate item to the users. In this paper, we analyze CF algorithms and present results for combined user-based/item-based CF algorithms for different size of datasets. Our goal is to show combined solution results using Loglikelihood, Spearman, Tanimoto and Pearson algorithms. The contribution is to describe which user based CF algorithms and user/item based combined CF algorithms perform better according to dataset, sparsity, execution time and k-neighborhood values. © 2012 IEEE.
  • 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: 6
    A Merging Clustering Algorithm for Mobile Ad Hoc Networks
    (Springer Verlag, 2006) Dağdeviren, Orhan; Erciyeş, Kayhan; Çokuslu, Deniz
    Clustering is a widely used approach to ease implementation of various problems such as routing and resource management in mobile ad hoc networks (MANET)s. We propose a new fully distributed algorithm for clustering in MANETs that merges clusters to form higher level clusters by increasing their levels. We show the operation of the algorithm and analyze its time and message complexities and provide results in the simulation environment of ns2. Our results conform that the algorithm proposed is scalable and has a lower time and message complexities than the other algorithms
  • Conference Object
    Citation - WoS: 8
    Citation - Scopus: 13
    A Distributed Backbone Formation Algorithm for Mobile Ad Hoc Networks
    (Springer Verlag, 2006) Dağdeviren, Orhan; Erciyeş, Kayhan
    Construction of a backbone architecture is an important issue in mobile ad hoc networks(MANET)s to ease routing and resource management. We propose a new fully distributed algorithm for backbone formation in MANETs that constructs a directed ring architecture. We show the operation of the algorithm, analyze its message complexity and provide results in the simulation environment of ns2. Our results conform that the algorithm is scalable in terms of its running time and roundtrip delay against mobility, surface area, number of nodes and number of clusterheads.
  • Conference Object
    Citation - WoS: 3
    Citation - Scopus: 5
    Serial and Parallel Multilevel Graph Partitioning Using Fixed Centers
    (Springer Verlag, 2005) Erciyeş, Kayhan; Alp, Ali; Marshall, Geoffrey
    We present new serial and parallel algorithms for multilevel graph partitioning. Our algorithm has coarsening, partitioning and uncoarsening phases like other multilevel partitioning methods. However, we choose fixed nodes which are at least a specified distance away from each other and coarsen them with their neighbor nodes in the coarsening phase using various heuristics. Using this algorithm, it is possible to obtain theoretically and experimentally much more balanced partitions with substantially decreased total edge costs between the partitions than other algorithms. We also developed a parallel method for the fixed centered partitioning algorithm. It is shown that parallel fixed centered partitioning obtains significant speedups compared to the serial case.
  • 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.
  • Conference Object
    Citation - WoS: 4
    Citation - Scopus: 4
    Merging Clustering Algorithms in Mobile Ad Hoc Networks
    (Springer Verlag, 2005) Dağdeviren, Orhan; Erciyeş, Kayhan; Çokuslu, Deniz
    Clustering is a widely used approach to ease implementation of various problems such as routing and resource management in mobile ad hoc networks (MANET)s. We first look at minimum spanning tree(MST) based algorithms and then propose a new algorithm for clustering in MANETs. The algorithm we propose merges clusters to form higher level clusters by increasing their levels. We show the operation of the algorithm and analyze its time and message complexities.
  • Conference Object
    Citation - Scopus: 2
    Crympix: Cryptographic Multiprecision Library
    (Springer Verlag, 2005) Koltuksuz, Ahmet; Hışıl, Hüseyin
    This paper delineates the results gained throughout the development of a cryptographic multiprecision1 integer library, CRYMPIX. To obtain the know-how for cryptographic computation and thus being able to create the high level cryptographic protocols in an in-housefashion are the main reasons of this development. CRYMPIX is mainly designed to supply code readability and portability plus an increased performance over other similar libraries. The whole work is achieved by detailed investigation of current algorithms and multi-precision libraries. The selected algorithms are discussed by means of efficiency and various implementation techniques. The comparative performance measurements of CRYMPIX against other multiprecision libraries show that the overall performance of CRYMPIX is not behind its predecessors if not superior.
  • 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.