Arama Sonuçları

Listeleniyor 1 - 8 / 8
  • Yayın
    Soft decision trees
    (IEEE, 2012) İrsoy, Ozan; Yıldız, Olcay Taner; Alpaydın, Ahmet İbrahim Ethem
    We discuss a novel decision tree architecture with soft decisions at the internal nodes where we choose both children with probabilities given by a sigmoid gating function. Our algorithm is incremental where new nodes are added when needed and parameters are learned using gradient-descent. We visualize the soft tree fit on a toy data set and then compare it with the canonical, hard decision tree over ten regression and classification data sets. Our proposed model has significantly higher accuracy using fewer nodes.
  • Yayın
    Çok-hipotezli süperpikseller ile sahne bölütleme ve etiketleme
    (IEEE, 2015-06-19) Ak, Kenan Emir; Ateş, Hasan Fehmi
    Süperpikseller son zamanlarda imge bölütleme ve sınıflandırma problemlerinde giderek önem kazanmaktadır. Sahne etiketlemede imge öncelikle bir süperpiksel algoritması ile görsel olarak tutarlı küçük parçalara bölütlenmekte; daha sonra süperpikseller farklı sınıflara ayrı¸stırılmaktadır. Sınıflandırma performansı kullanılan süperpiksel algoritmasının özellikleri ve parametre ayarlarından önemli ölçüde etkilenmektedir. Bu bildiride sahne etiketleme doğruluğunu iyileştirmek için birden fazla süperpiksel bölütleme sonucunu sınıflandırıcı seviyesinde kaynaştıran bir yöntem önerilmiştir. Öncelikle basit, parametrik olmayan ve eğitim gerektirmeyen SuperParsing algoritması kullanılarak süperpiksel etiketleri için olabilirlik oranları tespit edilir. Daha sonra alternatif süperpiksel bölütleme senaryoları için hesaplanan olabilirlik oranları piksel seviyesinde kaynaştırılarak, ilgili sahnenin bölütlenmesi ve etiketlenmesi tamamlanır. Önerilen yöntem 2,688 imge ve 33 etiket içeren SIFT Flow veri kümesi üzerinde test edilmiş ve SuperParsing’den daha yüksek sınıflandırma doğruluğu elde edilmiştir.
  • Yayın
    Regularizing soft decision trees
    (Springer, 2013) Yıldız, Olcay Taner; Alpaydın, Ahmet İbrahim Ethem
    Recently, we have proposed a new decision tree family called soft decision trees where a node chooses both its left and right children with different probabilities as given by a gating function, different from a hard decision node which chooses one of the two. In this paper, we extend the original algorithm by introducing local dimension reduction via L-1 and L-2 regularization for feature selection and smoother fitting. We compare our novel approach with the standard decision tree algorithms over 27 classification data sets. We see that both regularized versions have similar generalization ability with less complexity in terms of number of nodes, where L-2 seems to work slightly better than L-1.
  • Yayın
    VİSKON-RS : Uzaktan algılama ile hızlı afet hasar analiz yazılımı
    (IEEE, 2015-06-19) Kahraman, Fatih; İmamoğlu, Mümin; Özcan, Büşra Yüksel; Huruoğlu, Cengiz; Alasağ, Tolga; Gemici, Ömer Faruk; Hocaoğlu, Muhammet A.; Ateş, Hasan Fehmi
    Afet sonrası, acil müdahale ekiplerinin yönlendirilmesi ve iyileştirme çalışmalarının planlanması amacıyla hızlı hasar değerlendirmesine ihtiyaç duyulmaktadır. Bu çalışmada, AFAD ihtiyaçları doğrultusunda uzaktan (uzay/hava) algılama teknolojileri ile elde edilen görüntülerin afet hasar analizinde kullanılmasına yönelik VİSKON-RS yazılımı geliştirilmiştir. Geliştirilen yazılım; deprem, sel ve orman yangını gibi afet türlerinin hasar analizlerine özelleşmiş uygulamalar içermektedir. Ayrıca genel görüntü analizinde kullanılabilecek değişiklik analizi, eğitimli/eğitimsiz sınıflandırma, nesne tabanlı görüntü analizi ve doku analizi gibi uygulamalar yazılıma entegre edilmiştir. VİSKON-RS yazılımın temel amacı, afet sonrası uzaktan algılama verilerinin, açılması, işlenmesi, analiz edilmesi, sonuçların sergilenmesi ve karar destek sistemlerine aktarılması adımlarını içeren bütünleşik bir yazılım çözümü sunmaktır.
  • Yayın
    A novel approach to morphological disambiguation for Turkish
    (Springer-Verlag, 2012) Görgün, Onur; Yıldız, Olcay Taner
    In this paper, we propose a classification based approach to the morphological disambiguation for Turkish language. Due to complex morphology in Turkish, any word can get unlimited number of affixes resulting very large tag sets. The problem is defined as choosing one of parses of a word not taking the existing root word into consideration. We trained our model with well-known classifiers using WEKA toolkit and tested on a common test set. The best performance achieved is 95.61% by J48 Tree classifier.
  • Yayın
    Eigenclassifiers for combining correlated classifiers
    (Elsevier Science Inc, 2012-03-15) Ulaş, Aydın; Yıldız, Olcay Taner; Alpaydın, Ahmet İbrahim Ethem
    In practice, classifiers in an ensemble are not independent. This paper is the continuation of our previous work on ensemble subset selection [A. Ulas, M. Semerci, O.T. Yildiz, E. Alpaydin, Incremental construction of classifier and discriminant ensembles, Information Sciences, 179 (9) (2009) 1298-1318] and has two parts: first, we investigate the effect of four factors on correlation: (i) algorithms used for training, (ii) hyperparameters of the algorithms, (iii) resampled training sets, (iv) input feature subsets. Simulations using 14 classifiers on 38 data sets indicate that hyperparameters and overlapping training sets have higher effect on positive correlation than features and algorithms. Second, we propose postprocessing before fusing using principal component analysis (PCA) to form uncorrelated eigenclassifiers from a set of correlated experts. Combining the information from all classifiers may be better than subset selection where some base classifiers are pruned before combination, because using all allows redundancy.
  • Yayın
    Machine learning-based model categorization using textual and structural features
    (Springer Science and Business Media Deutschland GmbH, 2022-09-08) Khalilipour, Alireza; Bozyiğit, Fatma; Utku, Can; Challenger, Moharram
    Model Driven Engineering (MDE), where models are the core elements in the entire life cycle from the specification to maintenance phases, is one of the promising techniques to provide abstraction and automation. However, model management is another challenging issue due to the increasing number of models, their size, and their structural complexity. So that the available models should be organized by modelers to be reused and overcome the development of the new and more complex models with less cost and effort. In this direction, many studies are conducted to categorize models automatically. However, most of the studies focus either on the textual data or structural information in the intelligent model management, leading to less precision in the model management activities. Therefore, we utilized a model classification using baseline machine learning approaches on a dataset including 555 Ecore metamodels through hybrid feature vectors including both textual and structural information. In the proposed approach, first, the textual information of each model has been summarized in its elements through text processing as well as the ontology of synonyms within a specific domain. Then, the performances of machine learning classifiers were observed on two different variants of the datasets. The first variant includes only textual features (represented both in TF-IDF and word2vec representations), whereas the second variant consists of the determined structural features and textual features. It was finally concluded that each experimented machine learning algorithm gave more successful prediction performance on the variant containing structural features. The presented model yields promising results for the model classification task with a classification accuracy of 89.16%.
  • Yayın
    Analysis of the benefits, challenges and risks for the integrated use of BIM, RFID and WSN: a mixed method research
    (Emerald Group Publishing Ltd, 2023-07-11) Seyis, Senem; Sönmez, Alperen Mert
    Purpose The purpose of this study is to identify, classify and prioritize the benefits, challenges and risks for the integrated use of building information modeling (BIM), radio frequency identification (RFID) and wireless sensor network (WSN) in the architecture, engineering, construction and operation (AECO) industry. Design/methodology/approach This study relies on the mixed method approach which consists of systematic literature review, semistructured interviews and Delphi technique. A systematic literature review was performed and face-to-face semistructured interviews with seven subject matter experts (SMEs) were conducted for identification and classification purposes. Delphi method was applied in two structured rounds with eleven SMEs for prioritization purpose. These three research techniques were chosen to reach the most accurate data by combining different perspectives on the subject matter. Data gathered by these three methods was triangulated to increase the validity and reliability of this research. Findings Thirteen benefits, ten challenges and four risks for the integrated use of BIM, RFID and WSN were identified. The results could aid the practitioners and researchers comprehend the pros and cons of this integration by representing SMEs' valuable insights and perspectives about the current and future status, trends, limitations and requirements of the AECO industry. The identified risks and challenges show the requirements for future studies while the benefits demonstrate the capabilities and the potential contributions of this hybrid integration to the AECO industry. Originality/value The integration of BIM, RFID and WSN is still not commonly implemented in the AECO industry. Some studies focused on this topic; however, none of them reveals the benefits, risks and challenges for integrating BIM, RFID and WSN in a holistic manner. This research makes a significant contribution to the AECO literature and industry by uncovering the benefits, challenges and risks for the integrated use of BIM, RFID and WSN that could increase industry applications.