TR-Dizin İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/396
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Article YSA Kullanılarak Mamogramlardan Dokusal Öznitelik Tabanlı Meme Kanseri İlgi Bölgesi Sınıflandırılması(2020-12-29) Taşdemir, Sena Büşra Yengeç; Tasdemir, Kasim; Aydin, ZaferRadyoloji uzmanlarının mamografi görüntülerine bakarak yaptığı meme kanseriteşhislerinde tip bir hata oranı yüzde otuzlara kadar çıkmaktadır. Kanserin teşhisbaşarısını artırmak adına bu çalışmada uzmanlara yardımcı olacak yeni birBilgisayar Yardımlı Teşhis sistemi, kanserli ve normal dokuyu ayırt etmek içinönerilmektedir. Önerilen sistemde kontrast limitli histogram eşitleme (CLAHE)yöntemiyle iyileştirilen görüntülerin iki boyutlu parçacık dönüşümlerinden (2B–DWT) Haralick ve HOG öznitelikleri çıkarılmıştır. Özniteliklerin sayısını azaltmasıiçin temel bileşenler analizi (PCA) algoritması kullanılmıştır. Seçilen öznitelikler çokkatmanlı algılayıcı (MLP) mimari yapısına sahip yapay sinir ağına (YSA) girdi olarakverilmiştir. Çok katmanlı algılayıcı üzerinde Adam eniyileme yapıldığında %81tespit doğruluğu yakalanmıştır. Ayrıca, diğer bir çok temel makine öğrenmesi vederin öğrenme yöntemleri denenerek karşılaştırma sonuçları detaylı olaraksunulmuştur. Sınırlı sayıda veri kümesi kullanıldığında transfer öğrenim kullanılsadahi derin öğrenme yöntemlerinin tespit başarısı azalmıştır. Buna karşılık doğru önişleme, öznitelik seçilimi ve makine öğrenmesi yaklaşımları kullanıldığı zamangeleneksel bilgisayarlı görü yöntemleri daha başarılı sonuçlar vermiştirArticle Performance Analysis of Machine Learning and Bioinformatics Applications on High Performance Computing Systems(2020-01-31) Aydin, ZaferNowadays, it is becoming increasingly important to use the most efficient and most suitable computational resources for algorithmic tools that extract meaningful information from big data and make smart decisions. In this paper, a comparative analysis is provided for performance measurements of various machine learning and bioinformatics software including scikit-learn, Tensorflow, WEKA, libSVM, ThunderSVM, GMTK, PSI-BLAST, and HHblits with big data applications on different high performance computer systems and workstations. The programs are executed in a wide range of conditions such as single-core central processing unit (CPU), multi-core CPU, and graphical processing unit (GPU) depending on the availability of implementation. The optimum number of CPU cores are obtained for selected software. It is found that the running times depend on many factors including the CPU/GPU version, available RAM, the number of CPU cores allocated, and the algorithm used. If parallel implementations are available for a given software, the best running times are typically obtained by GPU, followed by multi-core CPU, and single-core CPU. Though there is no best system that performs better than others in all applications studied, it is anticipated that the results obtained will help researchers and practitioners to select the most appropriate computational resources for their machine learning and bioinformatics projects.Article Citation - WoS: 1New Modeling of Reconfigurable Microstrip Antenna Using Hybrid Structure of Simulation Driven and Knowledge Based Artificial Neural Networks(Pamukkale Univ, 2020) Aoad, Ashrf; Aydin, ZaferKnowledge-based modeling has a critical role to embed existing knowledge to improve modeling performance. Since reconfigurable antenna can provide more operational frequencies than the classical antennas, a knowledge-based hybrid structure is used in this work to obtain efficient model and producing optimum new models for a reconfigurable microstrip antenna. The hybrid structure consists of two phases. The first phase generates initial knowledge which is used in knowledge-based modeling structure to obtain design parameters. Artificial neural network based multilayer perceptron can generate necessary knowledge for a knowledge-based model after the training process. Knowledge-based modeling improves the accuracy of the initial model to determine design parameters corresponding to the design target. Source difference, prior knowledge Input and prior knowledge input with difference can be applied to realize an efficient knowledge-based strategy. 3D-EM simulation generates the new model in terms of the design parameters of the proposed application. It has three switching states for operating, which are organized by two resistor circuits representing ON/OFF states. Switch positions and geometrical parameters can be used for satisfying design targets between 1 GHz and 6 GHz for the efficient antenna design.Article Citation - Scopus: 6Network Intrusion Detection Based on Machine Learning Strategies: Performance Comparisons on Imbalanced Wired, Wireless, and Software-Defined Networking (SDN) Network Traffics(Turkiye Klinikleri, 2024-07-26) Hacilar, Hilal; Aydin, Zafer; Güngör, Vehbi ÇağrıThe rapid growth of computer networks emphasizes the urgency of addressing security issues. Organizations rely on network intrusion detection systems (NIDSs) to protect sensitive data from unauthorized access and theft. These systems analyze network traffic to detect suspicious activities, such as attempted breaches or cyberattacks. However, existing studies lack a thorough assessment of class imbalances and classification performance for different types of network intrusions: wired, wireless, and software-defined networking (SDN). This research aims to fill this gap by examining these networks’ imbalances, feature selection, and binary classification to enhance intrusion detection system efficiency. Various techniques such as SMOTE, ROS, ADASYN, and SMOTETomek are used to handle imbalanced datasets. Additionally, eXtreme Gradient Boosting (XGBoost) identifies key features, and an autoencoder (AE) assists in feature extraction for the classification task. The study evaluates datasets such as AWID, UNSW, and InSDN, yielding the best results with different numbers of selected features. Bayesian optimization fine-tunes parameters, and diverse machine learning algorithms (SVM, kNN, XGBoost, random forest, ensemble classifiers, and autoencoders) are employed. The optimal results, considering F1-measure, overall accuracy, detection rate, and false alarm rate, have been achieved for the UNSW-NB15, preprocessed AWID, and InSDN datasets, with values of [0.9356, 0.9289, 0.9328, 0.07597], [0.997, 0.9995, 0.9999, 0.0171], and [0.9998, 0.9996, 0.9998, 0.0012], respectively. These findings demonstrate that combining Bayesian optimization with oversampling techniques significantly enhances classification performance across wired, wireless, and SDN networks when compared to previous research conducted on these datasets. © 2024 Elsevier B.V., All rights reserved.
