WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14517/18

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Analysis and Implementation of Sensorless Pmsm Drive With Reduced Dc-Link Capacitance Under Parameter Variations
(Ieee, 2024) Sumsek, Reha Ozgur; Calik, Ramazan; Yavuz, Fikri Serkan; Kivanc, Omer Cihan
In AC drives used in heating, ventilation and air-conditioning applications, film capacitors are becoming widespread instead of electrolytic capacitors in DC-link. These drives with reduced capacitor value provide cost and volume advantages. However, dc-link oscillation increases due to the reduced capacity value. These oscillations cause instability, overvoltage and an increase in total harmonic distortion (THD). On the other hand, the winding temperatures of these motors, which operate continuously under rated operating conditions, reach 80 degrees C. The stator resistance and rotor flux value, which change with the increase in temperature, cause these drives, controlled without sensors, to operate even more unstable. In this study, a hybrid approach is proposed to improve the performance of the inverter using a 16 mu F film capacitor at the dc-link and to reduce the THD. The active damping method regulates the inverter output voltage for DC-link voltage stabilization. A permanent magnet synchronous machine (PMSM) sensorless speed control based on stator feedforward voltage estimation and a model reference adaptive system (MRAS) based on a multiparameter estimation algorithm is performed to minimize the effects of parameter variations. As a result of the experimental studies, it is observed that the grid input current complies with the IEC61000-3-2 standard, even under severe parameter variations.
Assessing Parents Perception of Environmental Awareness
(Stef92 Technology Ltd, 2013) Ozyaral, O.; Ayra, F.; Kaya, E.
It is inevitable to avoid from the influences of some adversities to arise in the ecosystem as "environmental risks" on our lives. The present study aims to determine the level of perception of parents on environmental awareness and environmental protection and to raise awareness on the environmental value and protection. In the present study, the questionnaires were administered to the parents of two private kindergarten students in Ki{dotless}zi{dotless}ltoprak-Erenköy districts on the Asian side of Istanbul as well as the parents of first and second grade students of a private primary school in Umraniye district on the Asian side of Istanbul. The parents of these first and second grade students and the kindergarten students were asked to fill in these questionnaires. A questionnaire prepared by the researchers and consisting of 76 questions was administered to the parents of the kindergarten students in order to measure their parents' environmental perception, 12 of which were prepared to measure the demographic characteristics and 64 of which were prepared for the perception measurement. In the study, the relations between the socio-economic and demographic characteristics of the parents and their environmental perceptions were tried to be found out. Moreover, to what extent the parents put into practice what they know was analyzed so that it can be shown how the information acquired affects the behavior acquisition. In line with the findings obtained, the fact that the awareness of the parents themselves on environment and ecosystem should be improved so that they can transfer the proper actions and approaches they have internalized to their children was found out. Emphasizing the environmental education in every part of the life and providing this education through non-governmental organizations and the experts and the efficiency of the media in this regard were among the results. In addition, the environmental awareness studies should begin during childhood for the sustainability of the environmental awareness education and the media studies should be heavily focused on so that the socio-cultural behavior changes could be ensured in the society and the social media studies should be made. © SGEM2013 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM.
Can Super Resolution via Deep Learning Improve Classification Accuracy in Dental Radiography
(Oxford University Press, 2025) Celik, Berrin; Mikaeili, Mahsa; Genç, Mehmet Zahid; Çelik, Mahmut Emin
Objectives Deep learning-driven super resolution (SR) aims to enhance the quality and resolution of images, offering potential benefits in dental imaging. Although extensive research has focused on deep learning based dental classification tasks, the impact of applying SR techniques on classification remains underexplored. This study seeks to address this gap by evaluating and comparing the performance of deep learning classification models on dental images with and without SR enhancement. Methods An open-source dental image dataset was utilized to investigate the impact of SR on image classification performance. SR was applied by 2 models with a scaling ratio of 2 and 4, while classification was performed by 4 deep learning models. Performances were evaluated by well-accepted metrics like structural similarity index (SSIM), peak signal-to-noise ratio (PSNR), accuracy, recall, precision, and F1 score. The effect of SR on classification performance is interpreted through 2 different approaches. Results Two SR models yielded average SSIM and PSNR values of 0.904 and 36.71 for increasing resolution with 2 scaling ratios. Average accuracy and F-1 score for the classification trained and tested with 2 SR-generated images were 0.859 and 0.873. In the first of the comparisons carried out with 2 different approaches, it was observed that the accuracy increased in at least half of the cases (8 out of 16) when different models and scaling ratios were considered, while in the second approach, SR showed a significantly higher performance for almost all cases (12 out of 16). Conclusion This study demonstrated that the classification with SR-generated images significantly improved outcomes. Advances in knowledge For the first time, the classification performance of dental radiographs with improved resolution by SR has been investigated. Significant performance improvement was observed compared to the case without SR. © 2025 Elsevier B.V., All rights reserved.
Capital: an Introduction To the Three Volumes
(Palgrave Macmillan, 2024) Savran, Sungur
Capital: the Book of Communism
(Palgrave Macmillan, 2024) Savran, Sungur
Chitosan Nanoplatforms as Carriers for Photodynamic and Photothermal Therapies in Cancer, Wound Healing, and Antimicrobial Applications
(Elsevier Ltd, 2026) Askari, S.; Eskandari, M.; Zarepour, A.; Khosravi, A.; Iravani, S.; Zarrabi, A.
Chitosan (CS)-based nanoplatforms have emerged as transformative tools in photodynamic (PDT) and photothermal (PTT) therapies, offering targeted, biocompatible solutions for cancer treatment, wound healing, and antimicrobial applications. Recent advancements include the design of multifunctional CS nanocomposites that enhance photosensitizer delivery, improve light-triggered efficacy, and enable synergistic therapies with reduced side effects. These developments address critical challenges in precision medicine, such as drug resistance and tissue regeneration, making this area of significant interdisciplinary interest. The tunable physicochemical properties of CS, combined with its biodegradability and antimicrobial activity, position it as a key material for next-generation therapeutic platforms. The future of this field depends on optimizing nanoplatform specificity, scalability, and clinical translation, with insights from this review guiding the rational design of advanced biomaterials. This review aims to provide a comprehensive overview of the recent advancements in CS-based nanomaterials specifically for PTT and PDT, while also addressing the associated challenges that hinder their clinical application. Moreover, it aims to highlight future perspectives that could enhance the effectiveness and applicability of chitosan-based therapies in cancer treatment. © 2025 Elsevier Ltd.
A Comparative Study of Biochemical, Antimicrobial Effects and Phytochemical Composition Analysis of Glycyrrhiza Glabra L. Varieties Root Extracts
(Marmara University, 2025) Gülmez, G.; Sen, A.; Servi, H.; Barak, T.H.; Tekin, F.; Marzi, M.; Şener, A.
Plants are the significant global interest as alternative treatment sources with their biologically active compounds. This study compares the chemical composition and the antioxidant, antidiabetic, and antimicrobial properties of ethanol extracts of G. glabra L. two different varieties from different regions. The phytochemical compositions was determined using GC-MS. Additionaly, total phenolic (TPC), flavonoid (TFC) and triterpene (TTC) contents were determined. Glycyrrhizic acid contents were analysed by HPLC. G. glabra var. glandulifera (GF1) showed the highest antioxidant activity. All extracts had strong antidiabetic effects, besides GF1 showing the highest effect. The MIC values was determined against 8 bacterial and 1 yeast strain and values ranged from 2.500 to 0.500; 2.500 to 0.714; 2.500 to 0.714 for G. glabra var. glabra (GB), GF1, G. glabra var. glandulifera (GF2) respectively. Phytochemical studies have shown that TPC was 100.60±5.06, 127.90±0.30, 69.01±0.30 mg GAE /g extract; TFC was 80.07±0.15, 25.35±0.0, 16.58±0.31 mg KE/g and TTC was 217.30±6.05,172.40±2.17, 126.30±4.50 mg OE/g extract for GB, GF1, GF2, respectively. GF1 in particular has the highest glycyrrhizic acid content. This study will contribute to the creation of new treatment strategies and potential therapeutic agents in addition to the use of G. glabra L. in traditional treatments. Our study is also a preliminary study for future studies. © 2025 Marmara University Press.
Comprehensive Health Assessment Based on ICF Components Using the WOMAC Index in Patients with Osteoarthritis
(Elsevier, 2024) Kabul, Elif Gur; Caglayan, Berna Cagla; Calik, Bilge Basakci; Kaymaz, Serdar; Karasu, Ugur
Introduction: Osteoarthritis (OA) is a common degenerative disease associated with functional impairment, activity limitation, participation restriction, and poor quality of life. Therefore, comprehensive assessment is important to determine how complex problems affect patients with OA. Objectives: The first aim of this study was to link and allocate items of The Western Ontario and McMaster Universities (WOMAC) OA index with the ICF Comprehensive Core Set for OA. The second aim was to examine the relationship between quality of life and each ICF component score based on WOMAC clinical data in OA. Materials and methods: Health status was evaluated with WOMAC and quality of life with the Nottingham Health Profile (NHP). The WOMAC items were linked with codes of the ICF Comprehensive Core Set for OA and allocated with the ICF components by three researchers. The relationship between WOMAC scores and the NHP was determined by Pearson correlation analysis. Results: 87 patients with OA were included. As distinguished by the researchers, 7 items of WOMAC covered body function and 17 covered activity-participation. Body function and activity-participation had a moderate correlation with the pain subtest of the NHP and low correlation with the energy level subtest and total score of the NHP. Activityparticipation had a high correlation with the physical abilities subtest of the NHP. Conclusion: Although WOMAC does not cover environmental factors, it is a comprehensive tool to assess health status and quality of life. Our results showed that in OA physical abilities can lead to limitations in activity and participation, and these limitations are associated with the individual's pain, energy level, and quality of life. (c) 2022 Asociacion Colombiana de Reumatolog & imath;a. Published by Elsevier Espa na, S.L.U. All rights reserved.
Confusions Concerning Sraffa (and Marx): Reply To Critics
(Palgrave Macmillan, 2024) Savran, Sungur
The Controversy Between the Neo-Ricardians and the Marxists
(Palgrave Macmillan, 2024) Savran, Sungur
A Cooperative Positioning Method of Connected and Automated Vehicles with Fusion of Data Information of Direction-of-Arrival Relative Distance and Vehicles Speed
(IEEE, 2025) Kaky, Kani M.; Bilgen, Semih
This study explores the potential of cellular-vehicle-to-everything (C-V2X) wireless communications in enhancing AV localization in GNSS-deprived scenarios. Specifically, we propose CV2X- LOCA, a novel unit (RSU)-assisted cooperative localization substructure utilizing only C-V2X channel state information to achieve lane-level precision. CV2X-LOCA comprises four main components: a data processing module, environment parameter correction module, coarse positioning module, and vehicle trajectory filtering module, collectively addressing challenges in dynamic C-V2X networks. Through extensive modelling we demonstrate that CV2X-LOCA attains cutting-edge localization performance even in noisy conditions, with fast-moving vehicles and sparse RSU coverage. The findings offer valuable insights for transportation agencies to make informed decisions regarding cost-effective RSU deployment in the future.
Critique of Political Economy
(Palgrave Macmillan, 2024) Savran, Sungur
(De)securitization of the Kurdish Issue in Turkey: the Nexus of Foreign Policy and Domestic Politics in the Twenty-First Century
(Palgrave Macmillan, 2023) Balaban, Gokce
Design and Implementation of a High Power Density GaN-Based USB-PD Charger
(IEEE, 2025) Er, Bugra; Bavtar, Gorkem; Kivanc, Omer Cihan
This paper presents the design and implementation of a high-power-density GaN-based USB-PD charger capable of delivering up to 100W. Gallium Nitride (GaN) power devices offer significant advantages over traditional silicon-based components, including higher efficiency, reduced switching losses, and increased power density, making them an ideal choice for modern fast-charging applications. In this study, various power conversion topologies and commercially available GaN-based integrated circuits (ICs) are analyzed and compared to determine the most efficient and thermally optimized solution. Extensive thermal analysis is performed to evaluate the heat dissipation and efficiency of the system under full-load conditions. Experimental tests verified the charger's performance, demonstrating high efficiency and superior thermal management compared to conventional silicon-based solutions. The results highlight the potential of GaN technology in achieving compact, efficient, and high-power-density USB-PD chargers suitable for next-generation consumer electronics.
Design of a Position Controlled Electric Actuator Used in Fluid Control Valves
(IEEE, 2016) Tosun, Gurkan; Kivanc, O. Cihan; Oguz, Ender; Mutlu, Yasar; Ustun, Ozgur
Valves are the main elements for controlling fluids in industry and other application areas. To control flow precisely, valves need a controlled action which leads to implement actuators, gear systems and electronic controllers. Increasing dominance of electrical actuators due to the advantages of easy control and intervention and space-efficient designs brings seldom implementation of hydraulic and pneumatic actuation. In fluid control applications, the main target is to obtain the right position, i.e. angle for rotary actuators, for adjusting flow rate. In this study, the design and implementation of a position controlled electrically actuated valve used for fluid control are presented. The design phases of system universal power supply and electronic control system are given and the experimental results of position control which are representing the validation the design study is also discussed. Also a special current control scheme is used to overcome transient disruptions.
Eco-Municipalities and Municipal Applications for Sustainability
(IGI Global, 2011) Bostancı, S.H.
Climate change effects, losses in natural environment, limited and diminishing energy sources are great threats for the countries in ecological and social aspects. In recent years some districts in Istanbul have been badly affected by disastrous floods. Climate change might have taken part of this problem but the main reason for the case is shanty housing, and poor location of settlements nearby to riversides, and even within riverbeds. All those experiences increase the necessity of the ecological planning for the settlements and of applying the Eco-municipal model for creating healthy environments. While some phenomena provide against the sustainable development of Turkish cities, solutions will be found in projects with ecological background. The eco-municipality models and municipal applications for sustainability are criticized for not yet finding a sustainable development model for Turkish municipalities. In the improvement of the sustainable municipality concept, some common decision had been taken and defined the related standards. LA21, EMAS for municipalities, and ISO standards are the examples coming forward. The methodology is based on literature review of experiences of the eco-projects that have been made in municipalities and SWOT analyses for these projects. In Turkey, the first step has been taken in LA21 processes to adopt the eco-municipal approach in transformation. For the further steps, the need for establishing an integrated model among the different applications has been concluded. © 2025 Elsevier B.V., All rights reserved.
Environmental Impacts of Micromobility
(Springer International Publishing AG, 2025) Karlikanovaite-Balikci, Agne
Globally, the e-scooter/e-bike network has already spread to more than 500 cities, 60 countries, and five continents, with the largest scooter rental companies counting tens of millions of registered trips. However, it is important to evaluate the environmental impact of these micromobility vehicles. Are these transportation options really as eco-friendly as the media and social networks claim? The fact that e-scooters/e-bikes do not emit gases from exhaust pipes does not necessarily mean that they do not create emissions and are completely eco-friendly. The environmental impact of these micromobility modes depends on their lifecycle, including production, distribution, and disposal. More than half of the emissions are generated from the extraction of necessary raw materials and the manufacturing process. Moreover, e-scooters/e-bikes require batteries that contain rare metals and whose production processes are energy-intensive. Shared e-scooter/e-bike services also involve energy-consuming charging and maintenance processes. Furthermore, e-scooters have a short lifespan, and improper disposal can pose environmental risks. E-scooters/e-bikes are frequently thrown into bodies of water, dropped from buildings, set on fire or otherwise damaged. The positive impact on the climate from manufacturing and using e-scooters/e-bikes could become a reality if significant attention is given to recyclable materials and sustainable development. Choosing renewable energy sources and optimizing every step of the service supply chain is also crucial for maintaining an efficient servicing system.
Exploration of Multi-Cultural Teaching and Learning in a Collaborative Virtual Environment
(IGI Global, 2011) Yamamoto, Gonca Telli; Featherstone, Michael; Karaman, Faruk; Borstorff, Patricia C.
This chapter presents an experiential case study of a multicultural virtual team project conducted by educators at two countries of three universities whose students came from very different cultural backgrounds. The authors suggest that new technologies present businesses and the institutions charged with training business professionals with a significant paradigm shift. Among the devices enterprises now employ to compete in the global business environment are virtual teams. We submit that it is incumbent upon educational institutions to formulate processes by which students may gain experience in the virtual work environment. The chapter details the experiences both students and instructors encountered in creating and participating in a cross-cultural virtual team conducted predominantly in a virtual environment. We describe problems encountered and often (though not always) overcome. Students learned both the rewards and the frustrations such teams experience as they learned to participate in and contribute to the collective intelligence of the team. © 2025 Elsevier B.V., All rights reserved.
Gender Equality in Turkey
(Palgrave Macmillan, 2023) Alemdar, Zeynep
The History of Micromobility
(Springer International Publishing AG, 2025) Dundar, Selim
Although it has been a part of our lives for a long time, it is difficult to pinpoint when micromobility, as a concept, actually began. This is because, up until almost two centuries ago, the speeds provided by micromobility vehicles were considered high within the transportation system. Therefore, it is quite challenging to define wheremicromobility diverges from general mobility. For this reason, in this chapter, the history of the transportation system is briefly examined first. The development of roads in the context of the need for transportation is discussed, linking it to human history, followed by a focus on the emergence of different types of transportation. After discussing the current situation, new and innovative transportation systems are briefly mentioned, and some insights are provided on what can be expected in the future. Then, the historical development of the bicycle, along with its different types and models, is discussed with support of figures. Lastly, the development of scooters, with a particular focus on shared e-scooter systems, is briefly summarized by examining some historical examples.

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