Arama Sonuçları

Listeleniyor 1 - 8 / 8
  • Yayın
    Incremental construction of rule ensembles using classifiers produced by different class orderings
    (IEEE, 2016) Yıldız, Olcay Taner; Ulaş, Aydın
    In this paper, we discuss a novel approach to incrementally construct a rule ensemble. The approach constructs an ensemble from a dynamically generated set of rule classifiers. Each classifier in this set is trained by using a different class ordering. We investigate criteria including accuracy, ensemble size, and the role of starting point in the search. Fusion is done by averaging. Using 22 data sets, floating search finds small, accurate ensembles in polynomial time.
  • Yayın
    İlişkisel veri tabanlarında mükerrer kayıtların makine öğrenmesiyle tespiti
    (Institute of Electrical and Electronics Engineers Inc., 2018-07-05) Bayrak, Ahmet Tuğrul; Yılmaz, Aykut İnan; Yılmaz, Kemal Burak; Düzağaç, Remzi; Yıldız, Olcay Taner
    Veri miktarının artışına paralel olarak, ilişkisel veri tabanlarında mükerrer kayıtlar da artmaktadır. Artan bu kayıtlar kullanıldıkları rapor veya analizlerde tutarsızlığa sebep olabilmektedir. Bu sorunu en aza indirgemek için yaptığımız çalışmada, kayıtların birbirlerine olan benzerlikleri ve alan uzmanlık bilgisiyle belirlenen ağırlıklar, öznitelik olarak kullanılarak makine öğrenmesi algoritmaları ile mükerrer kayıtların bulunması hedeflenmiştir. Yapılan işlem sonucunda 9301467 satır veride 28412 mükerrer çift tespit edilmiştir. Bulunan bu mükerrer kayıtlar veri kaynağından temizlenerek verinin daha tutarlı hale gelmesi sağlanmaktadır.
  • Yayın
    A new approach for named entity recognition
    (IEEE, 2017) Ertopçu, Burak; Kanburoğlu, Ali Buğra; Topsakal, Ozan; Açıkgöz, Onur; Gürkan, Ali Tunca; Özenç, Berke; Çam, İlker; Avar, Begüm; Ercan, Gökhan; Yıldız, Olcay Taner
    Many sentences create certain impressions on people. These impressions help the reader to have an insight about the sentence via some entities. In NLP, this process corresponds to Named Entity Recognition (NER). NLP algorithms can trace a lot of entities in the sentence like person, location, date, time or money. One of the major problems in these operations are confusions about whether the word denotes the name of a person, a location or an organisation, or whether an integer stands for a date, time or money. In this study, we design a new model for NER algorithms. We train this model in our predefined dataset and compare the results with other models. In the end we get considerable outcomes in a dataset containing 1400 sentences.
  • Yayın
    On the feature extraction in discrete space
    (Elsevier Sci Ltd, 2014-05) Yıldız, Olcay Taner
    In many pattern recognition applications, feature space expansion is a key step for improving the performance of the classifier. In this paper, we (i) expand the discrete feature space by generating all orderings of values of k discrete attributes exhaustively, (ii) modify the well-known decision tree and rule induction classifiers (ID3, Quilan, 1986 [1] and Ripper, Cohen, 1995 [2]) using these orderings as the new attributes. Our simulation results on 15 datasets from UCI repository [3] show that the novel classifiers perform better than the proper ones in terms of error rate and complexity.
  • Yayın
    Tree Ensembles on the induced discrete space
    (Institute of Electrical and Electronics Engineers Inc., 2016-05) Yıldız, Olcay Taner
    Decision trees are widely used predictive models in machine learning. Recently, K-tree is proposed, where the original discrete feature space is expanded by generating all orderings of values of k discrete attributes and these orderings are used as the new attributes in decision tree induction. Although K-tree performs significantly better than the proper one, their exponential time complexity can prohibit their use. In this brief, we propose K-forest, an extension of random forest, where a subset of features is selected randomly from the induced discrete space. Simulation results on 17 data sets show that the novel ensemble classifier has significantly lower error rate compared with the random forest based on the original feature space.
  • Yayın
    Feature extraction from discrete attributes
    (IEEE, 2010) Yıldız, Olcay Taner
    In many pattern recognition applications, first decision trees are used due to their simplicity and easily interpretable nature. In this paper, we extract new features by combining k discrete attributes, where for each subset of size k of the attributes, we generate all orderings of values of those attributes exhaustively. We then apply the usual univariate decision tree classifier using these orderings as the new attributes. Our simulation results on 16 datasets from UCI repository [2] show that the novel decision tree classifier performs better than the proper in terms of error rate and tree complexity. The same idea can also be applied to other univariate rule learning algorithms such as C4.5Rules [7] and Ripper [3].
  • Yayın
    Shallow parsing in Turkish
    (IEEE, 2017) Topsakal, Ozan; Açıkgöz, Onur; Gürkan, Ali Tunca; Kanburoğlu, Ali Buğra; Ertopçu, Burak; Özenç, Berke; Çam, İlker; Avar, Begüm; Ercan, Gökhan; Yıldız, Olcay Taner
    In this study, shallow parsing is applied on Turkish sentences. These sentences are used to train and test the per-formances of various learning algorithms with various features specified for shallow parsing in Turkish.
  • Yayın
    All-words word sense disambiguation for Turkish
    (IEEE, 2017) Açıkgöz, Onur; Gürkan, Ali Tunca; Ertopçu, Burak; Topsakal, Ozan; Özenç, Berke; Kanburoğlu, Ali Buğra; Çam, İlker; Avar, Begüm; Ercan, Gökhan; Yıldız, Olcay Taner
    Identifying the sense of a word within a context is a challenging problem and has many applications in natural language processing. This assignment problem is called word sense disambiguation(WSD). Many papers in the literature focus on English language and data. Our dataset consists of 1400 sentences translated to Turkish from the Penn Treebank Corpus. This paper seeks to address and discuss 6 different feature extraction methods and its classification performances using C4.5, Random Forests, Rocchio, Naive Bayes, KNN, Linear and multilayer Perceptron. This paper calls into question how the described features perform on a morphologically rich language (Turkish) with several classifiers.