WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653

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A Generalization of Fixed Point Result of Nonlinear Cirić Type Contraction on Suprametric Spaces
(Univ Nis, Fac Sci Math, 2025) Yalcin, Ceylan; Bilazeroglu, Seyma
In this study, the nonlinear technique: (psi,phi)-weak contraction, created by Dutta and Choudhury [6], is used to make the Ciric type contraction nonlinear. Moreover, it is demonstrated that there is unique fixed point in suprametric space for this nonlinear Ciric type contraction.
Citation - WoS: 10
Citation - Scopus: 10
About Lagrangian Formulation of Classical Fields Within Riemann-Liouville Fractional Derivatives
(American Society of Mechanical Engineers, 2005) Baleanu, D.; Muslih, S.I.
Recently, an extension of the simplest fractional problem and the fractional variational problem of Lagrange was obtained by Agrawal. The first part of this study presents the fractional Lagrangian formulation of mechanical systems and introduce the Levy path integral. The second part is an extension to Agrawal's approach to classical fields with fractional derivatives. The classical fields with fractional derivatives are investigated by using the Lagrangian formulation. The case of the fractional Schrödinger equation is presented. Copyright © 2005 by ASME.
About Nanometer Sized Analogues of Basic Electronic and Optical Components
(Ieee, 2008) Quandt, A.; Özdoǧan, C.; Ferrari, M.; Speranza, G.
We discuss a downsizing of optical components into the nanometer range. It presupposes the substitution of photons by ballistic electrons, but it also requires a simple and robust concept to assemble the analogues of basic electronic and optical components on such a tiny length scale. Here, one of the most promising candidate schemes employs graphene as a basic nanosubstrate. We elucidate the suggested behaviour of graphene as an electronic metamaterial [1], and show that other desired electronic or optical functionalities may be obtained through a patterning with sub-nanometer sized boron clusters [2]. © 2008 IEEE.
Citation - Scopus: 2
About the Fn Approximation To Fractional Neutron Transport Equation in Slab Geometry
(Amer Soc Mechanical Engineers, 2011) Baleanu, D.; Kadem, A.
The neutron transport denotes the study of the motions and interactions of neutrons with materials. In given applications we need to know where neutrons are in an apparatus, what direction they are moving, and how fast they are going. In this manuscript the Legendre polynomial approximation method F N was applied to the one dimensional slab geometry neutron transport equation. © 2011 by ASME.
Citation - Scopus: 2
Analysis of Delay Factors for Voice Over Wimax
(Ieee, 2008) Safak, A.; Preveze, B.
This paper presents the results of our computer simulation for delays experienced by voice packets over WiMAX 802.16e protocol running over an enterprise packet network connected to public internet. In the simulation we analyzed the effect of packet size, core network link speed, internet service provider link speed, wireless network link speed, wireless distance, base station range, and distance in internet parameters that effect the amount of delay in a WiMAX embedded IP network. In this study, all the delay parameters are fixed to their default values and current parameter values are changed so that the delay is varied between minimum and maximum values in uniformly distributed 100 steps and the delay is plotted in each step. Total fixed delays can be considered as minimum delay and variable delay corresponds to the maximum delay that can occur under the given conditions. All other fixed and variable delay parameters such as switching delays, packetization delays, contention delays and the delays caused by buffers etc. are also taken into account. The results indicate that among these delays WiMAX base station range and the number of base stations play the most decisive role. © 2008 IEEE.
Citation - Scopus: 2
An Application of Data Mining and Knowledge Discovery Process in the Field of Natural Gas Exploration
(Institute of Electrical and Electronics Engineers Inc., 2014) Acar, M.A.; Tolun, M.R.; Elbaşi, E.
Natural gas exploration has been shifting significantly in the last decades with the progression of new ingenious technologies. However, such technologies generates large amount of data sets and handling of them create problems such as interpretation of data. To solve such problems Data Mining techniques could be used. This work includes the application procedure of Data Mining and Knowledge Discovery to Natural Gas Well Log data using a set of algorithms and a decent Data Mining tool. And the success of each algorithm in terms of the amount of useful rules is compared.
Citation - Scopus: 2
Approaches on the Selection of Web Cameras and Calibration Targets for Stereo Vision
(Ieee, 2006) Eren, Haluk; Celik, Umit; Poyraz, Mustafa
In this paper, it is studied on the calibration by using specified web cameras. The performance of 3D computer vision depends on the accuracy of camera parameters. Therefore, camera calibration is very crucial in stereo vision. In this study, the options and selection of the target object that is used by the process of camera calibration are reviewed and evaluated some results obtained by web cameras. Webcams' costs are low relatively to the other digital consumer cameras but cannot be acquired a high resolution image.
Citation - WoS: 1
Assessing the Diffusion of Nanotechnology in Turkey: a Social Network Analysis Approach
(Taru Publications, 2012) Darvish, Hamid
According to the United Nations, nanotechnology is one of the emerging research fields which will have a positive impact on both developing and developed countries. For example, nanotechnology is used for water purification in poor countries. On the other hand, it is used in developed countries (rich) to manufacture better computer devices. Nanotechnology is a part of the strategic plan for each developing country. For example, the 7th European Union Scientific Framework (EUSF) has invested tremendously in nanotechnology since 2000. The Turkish government also has adopted a new approach by becoming part of the EUSF and has invested heavily in research and development. Focusing on an invisible college in the scientific community in Turkey, this study aims to evaluate the diffusion of nanotechnology among scientists. Using social network analysis metrics, we identified and analyzed the role and status of scientists in the two most prominent universities (Hacettepe University & Bilkent University) regarding nano-related technologies diffusion in Turkey. We found that co-authorship across the two universities is minimal, even in subject area research in both universities. However, the number of nano-related articles have increased exponentially in past decade in Turkey. Furthermore, a co-word analysis revealed the scientific trends in both universities. Keywords description revealed that the scientific trends in Hacettepe University are mostly nano biomedical research oriented whereas in Bilkent University scientific trends are metallurgical oriented in nano-related technologies. Data were derived from Thomson Reuters' Web of Science (WoS) version 4 database and CiteSpace was used to map the co-author network structure.
Citation - WoS: 1
The Association of Probable Adhd With the Increase in Video Gaming and the Disordered Gaming Symptom Severity During Covid-19 Pandemic in Turkey
(Yerkure Tanitim & Yayincilik Hizmetleri A S, 2021) Evren, Cuneyt; Evren, Bilge; Dalbudak, Ercan; Topcu, Merve; Kutlu, Nilay
Objective: The objective of the study is to examine the association of probable attention deficit hyperactivity disorder (ADHD) with the increase in video gaming and the severity of disordered gaming symptoms among young adults during the COVID-19 pandemic restrictions. The second objective was to examine the mediating role of COVID-19 related dysfunctional anxiety and current age. Methods: The Adult ADHD Self-Report Scale (ASRS-v1.1), the nine-item Internet Gaming Disorder Scale- Short Form (IGDS9-SF), and the Coronavirus Anxiety Scale (CAS) were used to evaluate university students. Results: Participants with probable ADHD (n=117, 21.2%) did not differ in terms of age, gender, romantic relationship, and employment status when compared with participants without probable ADHD (n=441, 79.0%). However, they had higher scale scores (IGDS9-SF and CAS). In the hierarchical logistic regression analysis, probable ADHD predicted the increase in video gaming during the pandemic, but when the current age and the dysfunctional anxiety related with COVID-19 were included in the analysis, they were significant predictors, whereas probable ADHD was no more a predictor. While probable ADHD was associated with the symptom severity of disordered gaming in ANCOVA, COVID-19 related dysfunctional anxiety was a significant covariate. Conclusion: Findings of the current study may suggest that the relationship between probable ADHD and the increase in video gaming during the pandemic was mediated by lower age and COVID-19 related dysfunctional anxiety among young adults. Additionally, while COVID-19 related dysfunctional anxiety was a significant covariate for the severity of disordered gaming symptoms, probable ADHD was independently associated with the symptom severity of disordered gaming.
AviBERT: Transformer Tabanlı Hava Aracı Metni Sınıflandırma
(Institute of Electrical and Electronics Engineers Inc., 2025) Unal, Muhammed Cihat; Yurtalan, Gokhan; Karatas, Yahya Bahadir; Karamanlioglu, Alper; Demirel, Berkan
In recent years, transformer-based models pre-trained on extensive corpora have played a critical role in the advancement of Natural Language Processing methodologies. Particularly, methods based on BERT have demonstrated remarkable performance across various tasks by offering robust capabilities in deeply understanding texts semantically. However, despite these advancements, there is a notable scarcity of studies applying these technologies in the aviation sector. This paper develops a multi-class classification model for aviation-specific texts using variants of BERT. The study encompasses the processes of collecting web content related to aircraft, labeling and model training. The details of the dataset are explained and the outcomes of the study are assessed based on the macro F1-score and accuracy of different models. © 2025 Elsevier B.V., All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
Cantor-Type Spherical-Coordinate Method for Differential Equations Within Local Fractional Derivatives
(de Gruyter Open Ltd, 2015) Rahmat, Mohamad Rah Segi; Baleanu, Dumitru; Yang, Xiao-Jun
In this article, we utilize the Cantor-type spherical coordinate method to investigate a family of local fractional differential operators on Cantor sets. Some examples are discussed to show the capability of this method for the damped wave, Helmholtz and heat conduction equations defined on Cantor sets. We show that it is a powerful tool to convert differential equations on Cantor sets from Cantorian-coordinate systems to Cantor-type spherical-coordinate systems.
Citation - WoS: 6
Citation - Scopus: 7
Chemometric Methods for the Simultaneous Spectrophotometnc Determination of Telmisartan and Hydrochlorotiazide in the Commercial Pharmaceuticals
(SYSCOM 18 S.R.L., 2009) Beliz, K.; Dinç, E.; Baleanu, D.
Simultaneous spectrophotometric determination of telmisartan (TEL) and hydrochlorothiazide (HCT) in two different commercial pharmaceutical preparations were performed by using three different chemometric methods, namely principal component regression (PCR), partial least squares (PLS) and artificial neural network (ANN). The proposed chemometric methods do not require chemical seperation and spectral graphical procedures for the quantitative resolution of mixtures containing the titled compounds. In the preparation of chemometric calibrations, a concentration set of 45 synthetic mixtures containing TEL and HCT in the linear concentration range of 1.0-26.0 and 7.0-7 7.0 pglmL, respectively was simetrically prepared in methanol. The spectra of the above concentration set and samples were recorded in the spectral range of 200-350 nm. Concentration set and its corresponding absorbances in the selected spectral range corresponding to the 250350 nm wavelength range was used to obtain PCR, PLS and ANN calibrations. Recovery study, intra-day, inter-day and standard addition technique were considered as method validation. Three proposed chemometric approaches were sucessfully applied to the quantitative analysis of two different commercial pharmaceutical products.
Comprehensive Analysis of Data Augmentation Methods in Classification for an Imbalanced Epilepsy Dataset
(Institute of Electrical and Electronics Engineers Inc., 2026) Calis, A.G.; Ergezer, H.
Imbalanced class distribution reduces the generalizability of classifiers in EEG-based epilepsy detection. This study examines the impact of the synthetic minority oversampling technique (SMOTE) and its variants on imbalanced electroencephalography (EEG) data, utilizing an end-to-end data processing pipeline. Band-limited filtering is applied as pre-processing, and then the training data is gradually oversampled by 20% increments in four scenes. Experiments are conducted on coarse-k-nearest neighbor (Coarse-KNN), bagged trees, and artificial neural network (ANN) classifiers, and evaluation is performed using accuracy, precision, recall, F1 score, and Matthew’s correlation coefficient (MCC) metrics. In Scene #4, where the inter-class imbalance is eliminated, Borderline-SMOTE yielded the highest and most consistent results (F1 Score = 0.903–0.937, MCC = 0.830–0.894). Safe level-SMOTE (SL-SMOTE) and SMOTE/Geometric-SMOTE(G-SMOTE) produced second-ranked results. The findings demonstrate that appropriate variant selection provides consistent gains even across classifiers, making Borderline-SMOTE the recommended approach for imbalanced EEG classification. Furthermore, in the detailed analysis of ensemble sampling limits, SMOTE-based combined approaches (e.g., SL + G SMOTE) also produced consistent results. Basic descriptive statistics (mode, median, variance, and kurtosis) of the synthetic samples were found to be comparable to those of the real data, providing additional evidence of distributional consistency. © 2013 IEEE.
A Configurable Can Fd Controller: Architecture and Implementation
(Institute of Electrical and Electronics Engineers Inc., 2017) Afsin, M.E.; Schmidt, K.W.; Schmidt, E.G.
CAN FD is a new standard which provides fast data rate while preserving the compatibility with CAN (controller area network). In this paper, a Configurable IP core architecture (A-CAN) which is compatible with the CAN FD standard, is proposed. Different than existing CAN/CAN FD controllers, the numbers and sizes of transmit and receive buffers of A-CAN can be configured in run time. To this end, A-CAN enables the best use of single controller hardware for different applications and enables improving the real time communication performance. A-CAN communicates with the host device over SPI without any specific interface requirements. A-CAN is implemented on an FPGA Evaluation Board and its functionally is verified at a rate of 2 Mbps. © 2017 IEEE.
Controller Synthesis With a Cone Complementarity Linearization Algorithm for CACC System Under Time-Varying Delay
(IEEE, 2025) Bingol, Hilal
Cooperative Adaptive Cruise Control (CACC) is an intelligent vehicle technology that enables vehicle follow-up in a small inter-vehicle distance. Stability is the main property of the CACC system that prevents any signal fluctuations throughout the vehicle string. In CACC system, time delay has a negative impact on string stability. The reason is that constant and varying time delays are unavoidable in real traffic. Here, controller gains should be synthesized under constant and time-varying communication delays to satisfy L-2-string stability conditions (in the Lyapunov sense). Contrary to previously studied convex method, controller gains are now synthesized with iterative nonlinear minimization algorithm and Cone Complementarity Linearization (CCL) method. The results show that the new CCL approach provides more accurate and practical stability bounds. Hence, this shows the potential of CCL to perform more sensitive analyses. The results obtained are evaluated by simulations with the heterogeneous CACC system.
Covariance Features for Trajectory Analysis
(IEEE, 2016) Karadeniz, Talha; Maras, Hadi Hakan
In this work, we aimed to demonstrate that covariance estimation methods can be used for trajectory classification. We have shown that, features obtained via shrunk covariance estimation are suitable for describing trajectories. We have arrived to the conclusion that, when compared to Dynamic Time Warping, the explained technique is faster and may yield more accurate results.
Crack Detection on Asphalt Runway Using Unmanned Aerial Vehicle Data With Non-Crack Object Removal and Deep Learning Methods
(Pontificia Universidad Catolica de Chile, Escuela de Construccion Civil, 2025) Tapkin, S.; Tercan, E.; Bostan, A.; Şengül, G.
Unmanned aerial vehicles are extensively utilized for image acquisition in a cheap, fast, and effective way. In this study, an automatic crack detection method with non-crack object removal and deep learning-based approaches are developed and tested on images captured by unmanned aerial vehicle. The motivation of this study is to detect either a crack exists or not in the asphalt-runway. The novelty of this study lies in integrating a non-crack artifact removal process with six classical edge detectors and comparing the resulting performance with four lightweight CNN models on the same UAV-acquired runway image dataset, enabling a unified evaluation of classical and learning-based approaches. For deep learning-based approach, four lightweight CNN models, namely GoogleNet, SqueezeNet, MobileNetv2, and ShuffleNet, are trained and the best accuracy of 87.9 is obtained whenever GoogleNet model is used. For the non-crack object removal approach, exclusion of non-crack objects from the images is the first step, where crack-detection which makes use of edge-detection techniques is the latter. In the study, Sobel, Prewitt, Canny, Laplacian of Gaussian, Roberts and Zero Cross edge detection algorithms are examined and their success rates in detecting cracks are comparatively presented. With sensitivity=0.981, specificity=0.744, accuracy=0.917, precision=0.912 and F-score=0.945 values Canny algorithm performs significantly better than others in detecting the cracks. This study provides enough evidence for the practicability of automated crack detection on unprocessed digital photographs by the results of the study conducted on asphalt runway. © (c) 2025 Tapkın, S., Tercan, E., Bostan, A. and Şengül, G. This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivatives 4.0 International License. https://creativecommons.org/licenses/by-nc-nd/4.0/
Citation - WoS: 1
Citation - Scopus: 1
Dengesiz Epilepsi Veri Seti İçin Sınıflandırmada Farklı SMOTE Yöntemlerinin Etkileri
(Institute of Electrical and Electronics Engineers Inc., 2025) Calis, Ahmet Gokay; Ergezer, Halit
In this study, the effects of different SMOTE methods on machine learning algorithms for the imbalanced epilepsy dataset were investigated. After filtering, the imbalanced dataset was balanced with 5 different SMOTE methods and classified with various machine learning algorithms. Coarse-K-Nearest Neighbor, Bagged Trees, and Artificial Neural Networks models were evaluated in epilepsy detection. The performance of these different models was compared with Matthews Correlation Coefficient (MCC) and F1 Score metrics. The results showed that the Borderline-SMOTE algorithm had the highest F1 Score and MCC values among all machine learning algorithms. © 2025 Elsevier B.V., All rights reserved.
Designing an Off-Road Working Lamp With Leds
(Istanbul Univ, Fac Engineering, 2011) Cil, Celal Zaim; Yakisir, Burcu; Girgin, Burcu Yakışır
In this study a working lamp used on the off-road working machines and vehicles is designed by using the LED diodes instead of a halogen bulb. In the design, firstly a LED array is determined and a proper driver circuit that can provide the required optical power is designed, and the working lamp developed is tested under various conditions. The luminous output values of the designed LED working lamp are compared with those of a commercial working lamp, which uses a halogen bulb. It is evaluated that in automotive applications lamps using LEDs could be successfully utilized depending on the optical efficacy of the LED used, the designs of the LED driver and the reflector.
Developing Growing Hierarchical Structures for Decision Making
(Ieee, 2007) Beldek, U.; Leblebicioglu, K.
This study is about developing a hierarchical approach for decision-making problems. The development is done on a representative decision-making problem. A hierarchical decision making approach which enables fusion of decisions of previous and current levels is proposed. The agents that determine the decisions at different hierarchy levels is accomplished by utilizing a genetic algorithm.

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