Browsing WoS İndeksli Yayınlar Koleksiyonu by Author "Dağ, Hasan"
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Alternative Credit Scoring and Classification Employing Machine Learning Techniques on a Big Data Platform
Hindistan, Yavuz Selim; Kiyakoğlu, Burhan Yasin; Rezaeinazhad, Arash Mohammadian; Korkmaz, Halil Ergun; Dağ, Hasan (Institute of Electrical and Electronics Engineers Inc., 2019)With the bloom of financial technology and innovations aiming to deliver a high standard of financial services, banks and credit service companies, along with other financial institutions, use the most recent technologies ... -
Applications of Eigenvalue Counting and Inclusion Theorems in Model Order Reduction
Yetkin, E. Fatih; Dağ, Hasan (Springer-Verlag Berlin, 2010)We suggest a simple and an efficient iterative method based on both the Gerschgorin eigenvalue inclusion theorem and the deflation methods to compute a Reduced Order Model (ROM) to lower greatly the order of a given state ... -
Branch outage simulation based contingency screening by gravitational search algorithm
Ceylan, Oğuzhan; Özdemir, Aydoğan; Dağ, Hasan (Praise Worthy Prize Srl, 2012)Power systems contingency analysis is an important issue for electric power system operators. This paper performs branch outage simulation based contingency screening using a bounded network approach. Local constrained ... -
Comparison of Cost-Free Computational Tools for Teaching Physics
Er, Neslihan Fatma; Dağ, Hasan (IEEE, 2010)It is widely accepted that it is quite difficult to engage today's students, from high schools to university, both in educational activities in class and "teaching" them physics due to their prejudices about the complexity ... -
Comparison of post outage bus voltage magnitudes estimated by harmony search and differential evolution methods
Ceylan, Oğuzhan; Özdemir, Aydoğan; Dağ, Hasan (2009)Contingency studies are indispensable tools of both the power system planning and operational studies. Real time implementation of operational problems makes necessary the use of high speed computational methods while ... -
Distributed Memory Parallel Transient Stability Analysis on a PC Cluster with Ethernet
Soykan, Gürkan; Flueck, Alexander J.; Dağ, Hasan (Praise Worthy Prize Srl, 2010)On-line transient stability analysis is a necessity for real-time power system control and security. Parallel processing is a natural technology for achieving real-time solution performance. This paper presents a ... -
Double branch outage modeling and simulation: Bounded network approach
Ceylan, Oğuzhan; Özdemir, Aydoğan; Dağ, Hasan (Elsevier Science, 2015)Energy management system operators perform regular outage simulations in order to ensure secure operation of power systems. AC power flow based outage simulations are not preferred because of insufficient computational ... -
Feature Extraction Based on Deep Learning for Some Traditional Machine Learning Methods
Çayır, Aykut; Yenidoğan, Işıl; Dağ, Hasan (Institute of Electrical and Electronics Engineers Inc., 2018)Deep learning is a subfield of machine learning and deep neural architectures can extract high level features automatically without handcraft feature engineering unlike traditional machine learning algorithms. In this ... -
A Generic Framework for Building Heterogeneous Simulations of Parallel and Distributed Computing Systems
Dursun, Taner; Dağ, Hasan (Springer Heidelberg, 2017)There have been many systems available for parallel and distributed computing (PDC) applications such as grids clusters super-computers clouds peer-to-peer and volunteer computing systems. High-performance computing (HPC) ... -
Heuristic Methods for Postoutage Voltage Magnitude Calculations
Ceylan, Oğuzhan; Özdemir, Aydogan; Dağ, Hasan (TUBITAK Scientific & Technical Research Council Turkey, 2016)Power systems play a significant role in every aspect of our daily lives. Hence their continuation without any interruption (or with the least duration of interruption due to faults or scheduled maintenances) is one of the ... -
The impact of text preprocessing on the prediction of review ratings
Işık, Muhittin; Dağ, Hasan (Tubitak, 2020)With the increase of e-commerce platforms and online applications, businessmen are looking to have a rating and review system through which they can easily reveal the feelings of customers related to their products and ... -
Improving Item-Based Recommendation Accuracy with User's Preferences on Apache Mahout
Jabakji, Ammar; Dağ, Hasan (IEEE, 2016)Recommendation systems play a critical role in the Information Science application domain especially in e-commerce ecosystems. In almost all recommender systems statistical methods and machine learning techniques are used ... -
Machine learning model to predict an adult learner's decision to continue ESOL course
Dahman, Mohammed R.; Dağ, Hasan (Springer, 2019)This study investigated the ability of the demographic and the affective variables to predict the adult learners' decision to continue ESOL courser. 278 adult learners, enrolled on ESOL course at FLS institution in Istanbul, ... -
A New Preconditioner Design Based on Spectral Division for Power Flow Analysis
Dağ, Hasan; Yetkin, E. Fatih; Manguoglu, Murat (Praise Worthy Prize Srl, 2011)Solution of large sparse linear systems is the most lime consuming part in many power system simulations. Direct solvers based on LU factorization although robust are known to have limited satiability on parallel platforms. ... -
On the selection of ınterpolation points for rational Krylov Methods
Yetkin, E. Fatih; Dağ, Hasan (Springer-Verlag Berlin, 2012)We suggest a simple and an efficient way of selecting a suitable set of interpolation points for the well-known rational Krylov based model order reduction techniques. To do this some sampling points from the frequency ... -
On-Line Transient Stability Assessment Using Matlab Parallel Programming Environment
Soykan, Gürkan; Dağ, Hasan (IEEE, 2010)Transient Stability Assessment (TSA) is the major part of Dynamic Security Assessment (DSA) in an electric power system. On-line TSA has gained more importance for power system security in last two decades. The decreasing ... -
Parallel Contingency Analysis Using Differential Evolution Based Solution For Branch Outage Problem
Ceylan, Oğuzhan; Dağ, Hasan; Özdemir, Aydoğan (IEEE, 2010)Contingency analysis is one of the most fundamental work an electricity management center operator has to perform regularly. If both bus voltage magnitudes and reactive power flowing on the branches during any type of ... -
Parallel Implementation Of Iterative Rational Krylov Methods For Model Order Reduction
Yetkin, E. Fatih; Dağ, Hasan (IEEE, 2010)Model order reduction (MOR) techniques are getting more important in large scale computational tasks like large scale electronic circuit simulations. In this paper we present some experimental work on multiprocessor systems ... -
Protecting openflow switches against denial of service attacks
Bahaa-Eldin, Ayman M.; ElDessouky, Ebada Mohamed Essam Eldin Ibrahim; Dağ, Hasan (Institute of Electrical and Electronics Engineers Inc., 2018)This paper presents a novel approach to protect Openflow switches against a type of Denial of Service (DoS) attacks. Openflow switches are the core of Software Defined Networks (SDN) and they are very flexible programmable ... -
Random CapsNet forest model for imbalanced malware type classification task
Çayır, Aykut; Ünal, Uğur; Dağ, Hasan (Elsevier, 2021)Behavior of malware varies depending the malware types, which affects the strategies of the system protection software. Many malware classification models, empowered by machine and/or deep learning, achieve superior ...