Scopus İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/1248

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Citation - WoS: 7
Citation - Scopus: 11
A 1-kW wireless power transfer system for electric vehicle charging with hexagonal flat spiral coil
(Tubitak Scientific & Technical Research Council Turkey, 2021) Aydin, Emrullah; AydemIr, M. Timur; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Wireless power transfer (WPT) technology is getting more attention in these days as a clean, safe, and easy alternative to charging batteries in several power levels. Different coil types and system structures have been proposed in the literature. Hexagonal coils, which have a common usage for low power applications, have not been well studied for high and mid power applications such as in electric vehicle (EV) battery charging. In order to fill this knowledge gap, the self and mutual inductance equations of a hexagonal coil are obtained, and these equations have been used to design a 1 kW WPT system with hexagonal coils for a mid-power stage EV charging. The theoretical and simulation results have been validated with an implementation in the laboratory and a DC-to-DC power efficiency of 85% is achieved across a 10 cm air gap between the perfect aligned coils. The misalignment performance of the system was observed for different positioning of the secondary coil, and the output power variation is given. In addition, the effect of shielding on magnetic field exposition of a driver sitting in an EV was obtained, and these simulation results were compared in order to check the compliance with international health standards.
Citation - WoS: 2
Citation - Scopus: 1
3D self-assemble formation of molybdenum disulfide (MoS2)-doped polyacrylamide (PAAm) composite hydrogels
(Tubitak Scientific & Technological Research Council Turkey, 2022) Durmaz, Sumeyye; Yildiz, Ekrem; Uysal, Bengu Ozugur; Pekcan, Onder; Molecular Biology and Genetics; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Polyacrylamide (PAAm), a renowned member of the hydrogel class, has many uses throughout a wide range of industrial processes, including water absorbed diapers, contact lenses, wastewater treatment, biomedical applications such as drug delivery vehicles and tissue engineering because of its physical stability, durability, flexibility easier shaping, and so on. PAAm also provides new functionalities after the incorporation of inorganic structures such as molybdenum disulfide (MoS2). During the copolymerization process, the transmittance of all samples reduced significantly after a particular time, referred to as the gel point. Microgels form a tree above the gel point as projected by Flory-Stockmayer classical theory. Because of microgels positioned at the junction points of the Cayley tree, the addition of MoS2 results in strong intramolecular crosslinking and looser composites. Moreover, fractal geometry provides a quantitative measure of randomness and thus permits characterization of random systems such as polymers. Fractal dimension of these polymer composites is calculated from power-law-dependent scattered intensity. It was also confirmed that a hydrogel rapidly formed within a few seconds, indicating a 3D network formation inside the gel. These materials may have a great potential for application in wearable and implantable electronics due to this highly desired 3D self-assemble feature.
Citation - Scopus: 2
Accented Essays: Documentary as Artistic Practice in Contemporary Audiovisual Works From Turkey
(Routledge, 2019) Akçalı,E.; Radio, Television and Cinema; 04. Faculty of Communication; 01. Kadir Has University
This article looks at the use of documentary filmmaking in contemporary artistic practices in Turkey, specifically focusing on three works that adopt a first-person, subjective viewpoint: Didem Pekün’s Of Dice and Men (2016), Şener Özmen’s How to Tell of Peace to a Living Dove? (2015), and Aykan Safoğlu’s Off-White Tulips (2013). Made by artists in transition, these films tackle themes of belonging and identity through stylistic choices proper to essayistic filmmaking, which allow these works to be regarded as accented essays. The personal questions raised through the aesthetics they employ become relevant to collective issues of culture, history, and memory, offering an alternative understanding of the social context, which was largely affected by the political events during the period in which they were made. © 2019, © 2019 Critical Arts.
Citation - WoS: 4
Citation - Scopus: 8
Accurate Indoor Positioning With Ultra-Wide Band Sensors
(Tubitak, 2020) Arsan, Taner; Computer Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Ultra-wide band is one of the emerging indoor positioning technologies. In the application phase, accuracy and interference are important criteria of indoor positioning systems. Not only the method used in positioning, but also the algorithms used in improving the accuracy is a key factor. In this paper, we tried to eliminate the effects of off-set and noise in the data of the ultra-wide band sensor-based indoor positioning system. For this purpose, optimization algorithms and filters have been applied to the raw data, and the accuracy has been improved. A test bed with the dimensions of 7.35 m x 5.41 m and 50 cm x 50 cm grids has been selected, and a total of 27,000 measurements have been collected from 180 test points. The average positioning error of this test bed is calculated as 16.34 cm. Then, several combinations of algorithms are applied to raw data. The combination of Big Bang-Big Crunch algorithm for optimization, and then the Kalman Filter have yielded the most accurate results. Briefly, the average positioning error has been reduced from 16.34 cm to 7.43 cm.
Citation - WoS: 12
Citation - Scopus: 15
Accurate Refinement of Docked Protein Complexes Using Evolutionary Information and Deep Learning
(Imperıal College Press, 2016) Akbal-Delibas, Bahar; Farhoodi, Roshanak; Pomplun, Marc; Haspel, Nurit; Computer Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
One of the major challenges for protein docking methods is to accurately discriminate native-like structures from false positives. Docking methods are often inaccurate and the results have to be refined and re-ranked to obtain native-like complexes and remove outliers. In a previous work we introduced AccuRefiner a machine learning based tool for refining protein-protein complexes. Given a docked complex the refinement tool produces a small set of refined versions of the input complex with lower root-mean-square-deviation (RMSD) of atomic positions with respect to the native structure. The method employs a unique ranking tool that accurately predicts the RMSD of docked complexes with respect to the native structure. In this work we use a deep learning network with a similar set of features and five layers. We show that a properly trained deep learning network can accurately predict the RMSD of a docked complex with 1.40 angstrom error margin on average by approximating the complex relationship between a wide set of scoring function terms and the RMSD of a docked structure. The network was trained on 35000 unbound docking complexes generated by RosettaDock. We tested our method on 25 different putative docked complexes produced also by RosettaDock for five proteins that were not included in the training data. The results demonstrate that the high accuracy of the ranking tool enables AccuRefiner to consistently choose the refinement candidates with lower RMSD values compared to the coarsely docked input structures.
Citation - WoS: 12
Citation - Scopus: 15
Acute Aortic Valve Regurgitation Secondary To Blunt Chest Trauma
(Texas Heart Inst., 2001) Ünal, Mehmet; Demirsoy, Ergun; Göğüş, Abdullah; Arbatlı, Harun; Hamzaoğlu, Azmi; Sönmez, Bingür; 01. Kadir Has University
Blunt injury to the cardiac valves leads to progressive acute ventricular failure which often requires urgent surgical management In this case report we describe an acute aortic valve rupture caused by air-bag inflation during an automobile accident. Laceration of an aortic valve cusp was treated successfully with urgent aortic valve replacement. A concomitant orthopedic injury was treated electively 15 days after cardiac surgery. Acute aortic valve rupture is a very rare complication of blunt chest trauma. We discuss how to diagnose and manage this potentially catastrophic event.
Citation - Scopus: 12
Acute Gastrointestinal Complications After Open Heart Surgery
(Asia Publishing Exchange Pte Ltd, 2000) Akpınar, Belhhan; Sağbaş, Ertan; Güden, Mustafa; Kemertas, Kubilay; Sönmez, Bingür; Bayındır, Osman; Demiroğlu, Cemşid; 01. Kadir Has University
Retrospective analysis revealed that 24 of 4401 adult patients (0.5%) developed severe gastrointestinal complications after open heart surgery during a 3-year period from January 1995. There were 4 women (17%) and 20 men (83%). Mean age was 61.7 ± 2.02 years. Gastrointestinal bleeding (33.3%) mesenteric ischemia (20.8%) pancreatitis (20.8%) hepatic dysfunction (16.7%) and cholecystitis (16.7%) were the most common complications. Mortality was 41.7% (10 patients). During the same period mortality in the patients who did not develop gastrointestinal complications was 1.89% (p < 0.0001). Emergency basis reoperation combined operations peripheral vascular disease diabetes mellitus chronic lung disease and impaired left ventricle function were found to be risk factors for the development of postoperative gastrointestinal complications.
Citation - WoS: 3
Citation - Scopus: 2
Adaptive Sampling Noise Mitigation Technique for Feedback-Based Quantum Algorithms
(Springer international Publishing Ag, 2024) Rahman, Salahuddin Abdul; Clausen, Henrik Glavind; Karabacak, Ozkan; Wisniewski, Rafal; Mechatronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Inspired by Lyapunov control techniques for quantum systems, feedback-based quantum algorithms have recently been proposed as alternatives to variational quantum algorithms for solving quadratic unconstrained binary optimization problems. These algorithms update the circuit parameters layer-wise through feedback from measuring the qubits in the previous layer to estimate expectations of certain observables. Therefore, the number of samples directly affects the algorithm's performance and may even cause divergence. In this work, we propose an adaptive technique to mitigate the sampling noise by adopting a switching control law in the design of the feedback-based algorithm. The proposed technique can lead to better performance and convergence properties. We show the robustness of our technique against sampling noise through an application for the maximum clique problem.
Advancing Image Spam Detection: Evaluating Machine Learning Models Through Comparative Analysis
(MDPI, 2025) Jamil, Mahnoor; Trpcheska, Hristina Mihajloska; Popovska-Mitrovikj, Aleksandra; Dimitrova, Vesna; Creutzburg, Reiner; 01. Kadir Has University
Image-based spam poses a significant challenge for traditional text-based filters, as malicious content is often embedded within images to bypass keyword detection techniques. This study investigates and compares the performance of six machine learning models-ResNet50, XGBoost, Logistic Regression, LightGBM, Support Vector Machine (SVM), and VGG16-using a curated dataset containing 678 legitimate (ham) and 520 spam images. The novelty of this research lies in its comprehensive side-by-side evaluation of diverse models on the same dataset, using standardized dataset preprocessing, balanced data splits, and validation techniques. Model performance was assessed using evaluation metrics such as accuracy, receiver operating characteristic (ROC) curve, precision, recall, and area under the curve (AUC). The results indicate that ResNet50 achieved the highest classification performance, followed closely by XGBoost and Logistic Regression. This work provides practical insights into the strengths and limitations of traditional, ensemble-based, and deep learning models for image-based spam detection. The findings can support the development of more effective and generalizable spam filtering solutions in multimedia-rich communication platforms.
Citation - WoS: 1
Citation - Scopus: 1
AI-Driven Predictive Maintenance for Workforce and Service Optimization in the Automotive Sector
(MDPI, 2025) Yildirim, Senda; Yucekaya, Ahmet Deniz; Hekimoglu, Mustafa; Ucal, Meltem; Aydin, Mehmet Nafiz; Kalafat, Irem; Industrial Engineering; Economics; Management Information Systems; 03. Faculty of Economics, Administrative and Social Sciences; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Vehicle owners often use certified service centers throughout the warranty period, which usually extends for five years after buying. Nonetheless, after this timeframe concludes, a large number of owners turn to unapproved service providers, mainly motivated by financial factors. This change signifies a significant drop in income for automakers and their certified service networks. To tackle this issue, manufacturers utilize customer relationship management (CRM) strategies to enhance customer loyalty, usually depending on segmentation methods to pinpoint potential clients. However, conventional approaches frequently do not successfully forecast which clients are most likely to need or utilize maintenance services. This research introduces a machine learning-driven framework aimed at forecasting the probability of monthly maintenance attendance for customers by utilizing an extensive historical dataset that includes information about both customers and vehicles. Additionally, this predictive approach supports workforce planning and scheduling within after-sales service centers, aligning with AI-driven labor optimization frameworks such as those explored in the AI4LABOUR project. Four algorithms in machine learning-Decision Tree, Random Forest, LightGBM (LGBM), and Extreme Gradient Boosting (XGBoost)-were assessed for their forecasting capabilities. Of these, XGBoost showed greater accuracy and reliability in recognizing high-probability customers. In this study, we propose a machine learning framework to predict vehicle maintenance visits for after-sales services, leading to significant operational improvements. Furthermore, the integration of AI-driven workforce allocation strategies, as studied within the AI4LABOUR (reshaping labor force participation with artificial intelligence) project, has contributed to more efficient service personnel deployment, reducing idle time and improving customer experience. By implementing this approach, we achieved a 20% reduction in information delivery times during service operations. Additionally, survey completion times were reduced from 5 min to 4 min per survey, resulting in total time savings of approximately 5906 h by May 2024. The enhanced service appointment scheduling, combined with timely vehicle maintenance, also contributed to reducing potential accident risks. Moreover, the transition from a rule-based maintenance prediction system to a machine learning approach improved efficiency and accuracy. As a result of this transition, individual customer service visit rates increased by 30%, while corporate customer visits rose by 37%. This study contributes to ongoing research on AI-driven workforce planning and service optimization, particularly within the scope of the AI4LABOUR project.
Citation - WoS: 1
Citation - Scopus: 1
Analysis of the Patients and Physicians Connection Network on an Online Health Information Platform
(IOS Press, 2014) Aydın, Mehmet Nafiz; Perdahci, N. Ziya; Management Information Systems; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Social network applications have gained popularity in the health domain as they bring health information seekers (patients and alike) and medication advice providers (physicians and other relevant actors) together. By employing a network science perspective this research is aimed to understand an information network establishing connections among and between information seekers and providers. We found that such a connection network surfaces most of the essential characteristics of a typical complex network. Furthermore a detailed structural analysis shows some intriguing relations and connection behaviours in the network. Implications of the findings are discussed from the perspectives of medical informatics and social network analysis.
Citation - WoS: 4
Citation - Scopus: 7
Atomic Force Microscopy and Spectroscopy Studies of Annealed Ce/Ti Mixed Oxide Thin Films Prepared by Sol-Gel Process
(Elsevier Science Bv, 2006) Ghodsi, Farhad E.; Tepehan, Fatma Zehra; Tepehan, Galip Gültekin; 01. Kadir Has University
Mixed Ce/Ti/Zr oxide thin films with a molar ratio of 0.5:0.25:0.25 were prepared using the sol-gel process and deposited on glass substrates by the dip coating technique. The effect of heat treatment temperature on surface morphology of the films was examined by atomic force microscopy AFM. The optical transmittance and reflectance of the films were measured over the spectral range from 350 to 1000 nm. The refractive index and extinction coefficient and thickness of the films were determined as a function of the heat treatment temperature. The refractive index increased from 1.51 to 2.02 at lambda = 600 nm and the extinction coefficient values increased from 0.006 to 0.094 while the thickness of the films decreased from 81 nm to 45 nm when annealing temperature increased from 100 degrees C to 500 degrees C. The results show that the optical properties and surface morphology of the mixed Cc/Ti/Zr oxide thin films were affected by annealing temperature. (c) 2006 Elsevier B.V. All rights reserved.
Attentional Modulation of Outlier Processing
(Springer, 2025) Gokce, Ahu; Yildirim, Bugay; Boduroglu, Aysecan; Psychology; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Ensemble perception enables the visual system to function effectively when the number of stimuli in the environment exceeds its capacity. Ensemble representations not only help the limited capacity of visual representations, but they also facilitate the detection and representation of items deviating from the group (i.e., the outlier). This study focuses on how attentional mechanisms modulate outlier processing. In three experiments, we presented participants with an ensemble that was formed by circle stimuli in varying sizes, and the outlier item was distinct in terms of its location. We measured outlier localization performance while manipulating attentional orienting via a spatial cueing paradigm. In Experiment 1, a valid, invalid, or neutral cue was presented before or after the display. Facilitation of outlier localization was most pronounced in the valid precue condition. Experiment 2 included a task to actively engage ensemble perception in addition to outlier localization, and cue validity effect was observed as in Experiment 1. Experiment 3A was carried to directly compare the top-down and bottom-up influences on outlier processing by presenting two spatial outliers-one target and another distractor outlier. The target outlier identity was previously determined and was identical across trials. In Experiment 3B, the target was in red, making it salient among the remaining items. In the invalid trials, where the distractor outlier was cued, responses were closer to the distractor item indicating that outlier processing is cue driven. These experiments overall demonstrate that automaticity of outlier processing can be overridden by cue-driven processes.
Attractiveness Differentially Affects Direct Versus Indirect Face Evaluations in Two Cultures
(Sage Publications Inc, 2023) Cassidy, Brittany S.; Saribay, S. Adil; Yuksel, Huseyin; Kleisner, Karel; Psychology; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Although decades of research have identified facial features relating to people's evaluations of faces, specific features have largely been examined in isolation from each other. Recent work shows that considering the relative importance of these features in face evaluations is important to test theoretical assumptions of impression formation. Here, we examined how two facial features of evolutionary interest, facial attractiveness and facial-width-to-height ratio (FWHR), relate to evaluations of faces across two cultures. Because face evaluations are typically directly measured via self-reports, we also examined whether these features exert differential effects on both direct and indirect face evaluations. Evaluations of standardized photos naturally varying in facial attractiveness and FWHR were collected using the Affect Misattribution Procedure in the United States and Turkey. When their relative contributions were considered in the same model, facial attractiveness, but not FWHR, related to face evaluations across cultures. This positive attractiveness effect was stronger for direct versus indirect evaluations across cultures. These findings highlight the importance of considering the relative contributions of facial features to evaluations across cultures and suggest a culturally invariant role of attractiveness when intentionally evaluating faces.
Citation - WoS: 14
Citation - Scopus: 16
Bayesian Compressive Sensing for Primary User Detection
(Inst Engineering Technology-IET, 2016) Başaran, Mehmet; Erküçük, Serhat; Cirpan, Hakan Ali; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
In compressive sensing (CS)-based spectrum sensing literature most studies consider accurate reconstruction of the primary user signal rather than detection of the signal. Furthermore possible absence of the signal is not taken into account while evaluating the spectrum sensing performance. In this study Bayesian CS is studied in detail for primary user detection. In addition to assessing the signal reconstruction performance and comparing it with the conventional basis pursuit approach and the corresponding lower bounds signal detection performance is also considered both analytically and through simulation studies. In the absence of a primary user signal the trade-off between probabilities of detection and false alarm is studied as it is equally important to determine the performance of a CS approach when there is no active primary user. To reduce the computation time and yet achieve a similar detection performance finally the effect of number of iterations is studied for various systems parameters including signal-to-noise-ratio compression ratio mean value of accumulated energy and threshold values. The presented framework in this study is important in the overall implementation of CS-based approaches for primary user detection in practical realisations such as LTE downlink OFDMA as it considers both signal reconstruction and detection.
Citation - WoS: 1
Citation - Scopus: 1
Bayesian Estimation of Discrete-Time Cellular Neural Network Coefficients
(TUBITAK Scientific & Technical Research Council Turkey, 2017) Özer, Hakan Metin; Özmen, Atilla; Şenol, Habib; Computer Engineering; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
A new method for finding the network coefficients of a discrete-time cellular neural network (DTCNN) is proposed. This new method uses a probabilistic approach that itself uses Bayesian learning to estimate the network coefficients. A posterior probability density function (PDF) is composed using the likelihood and prior PDFs derived from the system model and prior information respectively. This posterior PDF is used to draw samples with the help of the Metropolis algorithm a special case of the Metropolis--Hastings algorithm where the proposal distribution function is symmetric and resulting samples are then averaged to find the minimum mean square error (MMSE) estimate of the network coefficients. A couple of image processing applications are performed using these estimated parameters and the results are compared with those of some well-known methods.
Citation - WoS: 3
Citation - Scopus: 3
Beliefs of Living Donors About Recipients' End-Stage Liver Failure and Surgery for Organ Donation
(Elsevier Science Inc, 2017) Krespi-Boothby, Margörit Rita; Tankurt, A.; Acarli, Koray; Kanmaz, Turan; Yankol, Yucel; Kalayoğlu, Murat; Psychology; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Background. The concept of beliefs could provide a basis for how donors may perceive recipients' end-stage liver failure (ESLF) and surgery for organ donation. However there is no such quantitative study. Therefore the objective of this study was to explore beliefs of living donors about recipients' ESLF and surgery for organ donation. Methods. The sample comprised 16 living donors who donated a part of their liver to a patient who had ESLF. The data were analyzed by following established procedures for inductive qualitative analysis. Results. Analysis showed that donors' beliefs can be viewed in a number of groups. Beliefs about recipients' ESLF included diverse explanations for ESLF (blaming oneself and physicians) and physical symptoms (developmental slowing down). Beliefs about being a donor included reasons for being a donor (performing a good deed being healed) barriers to being a donor (other people being ignorant and selfish) ways to manage these barriers (following one's gut feeling) and factors facilitating being a donor (the feeling that one does not have many people to leave behind). Beliefs about surgery for organ donation included physical effects (pain feeling stiff). Beliefs about organ donation included views that general organ donation should be encouraged and that people's awareness should be raised. Conclusions. Existing psychological perspectives could help to interpret some beliefs. Nevertheless other beliefs not previously reported could be considered as targets for individual consultations/psycho-educational programs for fostering emotional well-being.
Beyond the Quest for a Technological Holy Grail: Patterns of Income Inequality and the Household Carbon Footprint in Turkey
(Cambridge University Press, 2025) Gürer, E.; Satloglu, B.; Voyvoda, E.; Erinç Yeldan, A.; 01. Kadir Has University; 03. Faculty of Economics, Administrative and Social Sciences; Economics
Utilizing data on household consumption expenditure patterns and sectorial greenhouse gas emissions, we study the extent of inequality over Turkish households' differentiated carbon footprint incidences. We harmonize the household budget survey data of the Turkish Statistical Institute (TURKSTAT) with production-based gas emissions data from EXIOBASE3 and investigate both the direct and indirect emissions across household-level income strata. Our calculations reveal that the households in the highest income decile alone are responsible for 19.4 percent of the overall (direct and indirect) emissions, whereas the bottom 10 percent of households are responsible for 4.3 percent. We also find that for direct emissions, the per-household average of the highest income decile exceeds that of the lowest income decile by a factor of 11.2. Notably, 87 percent of the indirect emissions budget for the poorest decile is linked to food and housing expenses, underscoring their susceptibility to climate policies. We confer that in designing the net-zero emission pathways to combat climate change, it would not suffice to study the technological transition of decarbonization solely and that the successful implementation of an indigenous environmental policy will ultimately depend upon the socio-economic factors of income distribution strata, indicators of consumption demand, and responsiveness of the individual households to react to price signals. © 2025 The Author(s).
Bianchi Surfaces Whose Asymptotic Lines Are Geodesic Parallels
(Walter De Gruyter Gmbh, 2015) Arsan, Güler Gürpınar; Özdeğer, Abdulkadir; 01. Kadir Has University
It is proved that every Bianchi surface in E-3 of class C-4 whose asymptotic lines are geodesic parallels is either a helicoid or a surface of revolution.
Citation - Scopus: 4
Bilateral Macrostomia as an Isolated Deformity and Its Repair With a Modified Technique
(Springer Verlag, 2002) Peker, Fatih; Açıkel, Cengiz; Karacaoğlu, Ercan; Durak, Nazım; 01. Kadir Has University
A 3-year-old boy with bilateral congenital macrostomia as an isolated clinical entity is presented. Although this is a rare deformity, it causes functional and cosmetic problems which are difficult to correct. The skin, muscle, and mucosal components of the deformity were separately repaired using a modification of Kaplan's technique.

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