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.
Analysis of the Factors Affecting the Latency Period and Type of Birth in Patients With Preterm Prematur Rupture of Membranes
(Dokuz Eylul Univ inst Health Sciences, 2022) İlhan, Yunus; Kuzu, Ozan; Gozel, Sercan; Yumru, Ayşe Ender
Purpose: To determine the factors associated with the latent period in patients with preterm premature rupture of membranes (PPROM). Material and Methods: 53 patients who applied to our clinic within 1 year and were diagnosed with PPROM and met the inclusion criteria participated in this prospective cross-sectional study. Factors thought to affect the latent period in these patients were examined in terms of delivery time and mode. Results: Latent period; was negatively correlated with dilatation and positively correlated with collum length. The mean latent time of patients with contraction was statistically significantly lower than those without. In another model, gestational week, collum length and birth weight were found to be the most significant factors associated with the latent period. In the latent period groups; Statistically, a significant difference was found in the mean dilatation and collum length. The contraction rate was higher in those with a latency period of 2 days or less. Conclusion: Latent duration is inversely proportional to dilatation and directly proportional to collum length. Uterine contraction is higher in patients with a latency period of fewer than 2 days. Other statistically significant factors related to the latent period are the gestational week and the fetal weight.
An Analysis of the Tourism-Led Growth Hypothesis in Turkey at the Provincial Level: A Dynamic Panel Data Approach
(Maliye Bakanligi, 2024) Cinar, Sinan; Has, Banu
This study examines the impact of tourism on economic growth in Turkey at the provincial level using data from the 2008-2020 period and dynamic panel data analysis. Analyses conducted with the Augmented Solow-Swan Model reveal that technology, labor, physical capital, and tourism positively contribute to growth, while human capital has a negative effect. The study makes a unique contribution to the literature as the first research to analyze the impact of tourism on economic growth in Turkey using the most recent provincial data and this model. The findings indicate that the tourism-led growth hypothesis is valid for Turkey.
Asthmatic Patients: Is Homocysteine an Issue
(Galenos Publ House, 2024) Keskinel, İlkay; Eryilmaz, Müzeyyen; Güntürk, Arzu
Objective: Understanding the causes of asthma is crucial for developing new therapeutic modalities. Homocysteine (HCY) is an intermediate in methionine metabolism. Elevated HCY levels may indicate folate and vitamin B12 deficiencies, which are cofactors for the methylation of HCY to methionine. The relationship between hyperHCY mia and atherosclerosis is well-documented, and it is considered a cause of cardiovascular, neurodegenerative, and ocular diseases. HyperHCY mia may also cause atopy and, consequently, asthma. We aimed to evaluate the levels of HCY, vitamin B12, and folic acid in asthmatic patients and healthy adults, as well as to determine whether correlations exist between these levels and lung function, eosinophil counts, total immunoglobulin E (IgE), and eosinophilic cationic protein (ECP) levels in asthmatic subjects. Methods: A total of 142 asthmatic patients and 36 healthy controls were enrolled in the study. Folic acid, vitamin B12, total IgE, ECP, eosinophil percentage, eosinophil counts, and HCY levels were evaluated in both groups. Results: HCY, vitamin B12, and folic acid levels did not significantly differ between patients with asthma and controls. There was a statistically significant positive correlation (at the 0.95 confidence level) between HCY values and forced vital capacity, peak expiratory flow (PEF), and eosinophil counts in patients with asthma. Folic acid levels correlated positively only with PEF%, whereas vitamin B12 levels did not correlate with any functional parameters or atopic markers like IgE and ECP. Conclusion: Should large-scale randomized controlled trials conclusively establish HCY as a causative factor of asthma, metabolic interventions to lower HCY levels using methyl donors could be considered alongside conventional asthma treatments.
Attıtudes of Female Employees In Nutrıtıon of 9 Months-6 Years Old Chıldren In Covıd-19
(Jpms Publ, 2024) Demir, Ibrahim; Onal, Ayse Emel; Ayvaz, Ozkan; Onal, Mehmet Erinc; Onal, Emel Ruya; Yildiz, Sevda Ozel
Background: We aimed to determine the factors affecting the nutritional attitudes of female hospital workers toward their children between 9 months and 6 years of age during the COVID-19 pandemic.Methods: Our study, which is an original article, was conducted with female employees working in the hospital and having children between the ages of 9 months and 6 years. The impact of changes in work and home life during COVID-19 on changes in child care and child nutrition has been questioned. Result: Statistical significance was detected between the scale and questions such as the frequency of anxiety regarding the child's illness during the COVID19 process, the decrease in the child's appetite, changes in the child's eating pattern, the mother's relationship with the environment and social relations, and the child's sleep pattern. Conclusion: A significant relationship was found between inadequate/unbalanced nutrition and educational status and between the reaction to others' opinions sub-dimension and age groups. Moreover, another significant relationship was found between the frequency of anxiety about the child's illness and the scale, and between the change in the child's nutrition pattern and the scale. The COVID-19 pandemic affected the attitudes of female employees towards the nutrition of their children.
Autoimmune Encephalitis and Musicogenic Epilepsy: a Case of Gad65 Antibody-Associated Seizure
(Wiley, 2025) Mohammadi-Asl, Ali; Bahadori, Amir Reza; Sabzgolin, Iman; Davari, Afshan; Razmafrooz, Mohammad; Tafakhori, Abbas; Ranji, Sara
Musicogenic epilepsy (ME) is a rare form of reflex epilepsy with a prevalence of 1 in 10,000,000. Recent research suggests a potential link between ME and autoimmune encephalitis, particularly involving glutamic acid decarboxylase 65-isoform (GAD65) antibodies. A 48-year-old female presented with a one-year history of music-triggered seizures. Her episodes were characterized by an initial aura followed by unresponsiveness and oral automatisms. Electroencephalography revealed abnormalities in the left anterior temporal lobe and temporal leads. Laboratory studies showed positive anti-GAD65 antibodies. The patient was treated with a combination of antiepileptic medication (Lamotrigine) and corticosteroids and intravenous immunoglobulin. This case contributes to the growing evidence supporting an association between ME and autoimmune mechanisms, particularly GAD65 antibody-mediated autoimmunity. It highlights the importance of screening autoimmune factors in ME patients and highlights the need for further research into targeted treatment strategies.
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
Challenges and Adjustment of Self-Initiated Expatriates in Türkiye
(Eskisehir Osmangazi Univ, Fac Education, 2025) Khemiri, Eya; Yagiz, F. Nazli Saygan
In the study of expatriation and expatriate adjustment there are limited studies that focus on issues faced by self- inititated expatriates in T & uuml;rkiye. The objective of this study is to analyse the challenges and adjustment of self-initiated expatriates in T & uuml;rkiye. Purposive sampling was used for participant selection. 11 expatriates from 7 countries living and working in Istanbul were interviewed and thematic analysis was used to interpret the qualitative data. MAXQDA 2018 data analytic program was utilized. The study identified five main themes: reasons of relocation, challenges, factors facilitating the expatriate adjustment, coping strategies in adjustment and intent to stay in T & uuml;rkiye.
Comparative Analysis of Transaction Performance in Different Virtualization Environments
(Istanbul Univ, 2024) İncereis, Nilgün; Candemir, Ali İhsan
Virtualization technologies are increasing in importance day by day. The selection of virtualization software is an important factor to realize efficient use of physical hardware. In this study, the Ubuntu 22.04 LTS operating system was run on Virtu- alBox, VMware, and Docker, which are widely used virtualization software. Then, the Tiobench, Compress-7zip, C-ray, Smallpt, Tachyon, and OSBench tests were per- formed on the Ubuntu operating system with the Phoronix Test Suite software, and the test results were analyzed and compared. The results demonstrate that Docker out- performed the other virtualization technologies, although not in every test. Owing to its rapid deployment and efficient use of resources, Docker is suitable for applications that require agility and scalability. However, traditional virtualization technologies, such as VMware, may be more suitable for applications that require high security and extensive resource management. In addition, this study provides information that can guide users in selecting virtualization software.
Comparison of Posterior and Antero-Lateral Renal Tumors in Retroperitoneal Laparoscopic Partial Nephrectomy: a Propensity Score Matching Analysis
(Codon Publications, 2023) Anil, Hakan; Yildiz, Ali; Guzel, Ahmet; Akdemir, Serkan; Karamik, Kaan; Arslan, Murat
This study aimed to compare the antero-lateral and posterior localized renal masses in laparoscopic partial nephrectomy with the retroperitoneal approach in terms of operative, functional, and oncological outcomes. Patients who underwent retroperitoneal laparoscopic partial nephrec-tomy by a single surgeon between January 2013 and January 2021 were included in the study. A one-to-one propensity score matching (PSM) analysis was conducted to obtain two balanced groups. The patients were divided into two groups as posterior and antero-lateral according to the localization of the mass. A total of 239 patients were included in the PSM analysis, with 65 patients allocated to each group. The mean operative time was 79.2 & PLUSMN; 11.2 min in the posterior group, while it was 90.0 & PLUSMN; 11.6 min in the antero-lateral group (P < 0.001). Warm ischemia time was 15.9 & PLUSMN; 2.4 min in the posterior group and 18.6 & PLUSMN; 2.7 min in the antero-lateral group (P < 0.001). The median decrease in eGFR at 1 year was 4.8 (IQR, 2.9-6.9) mL/min in the posterior group and 5.0 (IQR, 2.8-11) mL/min in the antero-lateral group (P = 0.219). The warm isch-emia time and clamping technique were found to be significant factors for predicting eGFR change after surgery (13:0.693, 95% CI: 0.39-0.99, P < 0.001; 13:6.43, 95% CI: 1.1-11.7, P = 0.017, respectively). We report that retroperitoneal laparoscopic partial nephrectomy provided longer warm ischemia and operative time for antero-lateral renal masses than posterior masses. However, long-term oncological and functional results were similar for both localizations.
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.
COVID-19 Seroprevalence in Cirrhotic Patients and Effect of COVID-19 Infection on Liver Cirrhosis by Clinical Form in the Postinfectious Period
(Galenos Publ House, 2024) Ozbey, Dogukan; Kocazeybek, Bekir S; Hatemi, Ali Ibrahim; Sonsuz, Abdullah; Eşkazan, Tuğçe; Bakkaloglu, Oguz Kagan; Önal, Uğur
Introduction: There are very few studies demonstrating the seroprevalence of coronavirus disease-2019 (COVID-19) in patients with cirrhosis worldwide and in Turkey. This study aimed to investigate the seroprevalence of COVID-19 in patients with cirrhosis and its effect on liver cirrhosis by clinical form in the postinfectious period. Methods: The study included 174 patients with cirrhosis. Patients with COVID-19 were identified using anti-severe acute respiratory syndrome-coronavirus-2-immunoglobulin G (SARS-CoV-2-IgG) and COVID-19 polymerase chain reaction assays and were divided into symptomatic and asymptomatic groups. The last polyclinic records of the patients before infection or testing were determined as 1st examination and the date of blood collection for anti-SARS-CoV-2-IgG was determined as the 2nd examination. Examination findings and liver tests of the patients in both periods were recorded; Child-Pugh Score (CPS) and Model for End Stage Liver Disease (MELD)-Na scores were calculated. Additionally, patients were evaluated for newly developed hepatic decompensation. Results: The seropositivity of anti-SARS-CoV-2-IgG was detected in 35.6% of our patients, and the rate of those who had symptomatic COVID-19 infection was 23.6%, whereas the rate of those who had asymptomatic infection was 12%. There was no significant difference in liver tests, CPS, and MELD-Na scores before and after COVID-19 infection between symptomatic and asymptomatic patients, and new decompensation was found in 9.6% of patients with COVID-19 infection. Conclusion: The incidence of COVID-19 among patients with liver cirrhosis is notably high. Although high decompensation rates were reported in the acute phase of the disease, such rates were not observed in the postinfectious period. Ultimately, our results indicated no significant difference in the course of existing liver disease according to clinical form.
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.

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