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Conference Object Citation - WoS: 4Citation - Scopus: 6A Reinforcement Learning Algorithm for Data Collection in Uav-Aided Iot Networks With Uncertain Time Windows(Ieee, 2021) Cicek, Cihan TugrulUnmanned aerial vehicles (UAVs) have been considered as an efficient solution to collect data from ground sensor nodes in Internet-of-Things (IoT) networks due to their several advantages such as flexibility, quick deployment and maneuverability. Studies on this subject have been mainly focused on problems where limited UAV battery is introduced as a tight constraint that shortens the mission time in the models, which significantly undervalues the UAV potential. Moreover, the sensors in the network are typically assumed to have deterministic working times during which the data is uploaded. In this study, we revisit the UAV trajectory planning problem with a different approach and revise the battery constraint by allowing UAVs to swap their batteries at fixed stations and continue their data collection task, hence, the planning horizon can be extended. In particular, we develop a discrete time Markov process (DTMP) in which the UAV trajectory and battery swapping times are jointly determined to minimize the total data loss in the network, where the sensors have uncertain time windows for uploading. Due to the so-called curse-of-dimensionality, we propose a reinforcement learning (RL) algorithm in which the UAV is trained as an agent to explore the network. The computational study shows that our proposed algorithm outperforms two benchmark approaches and achieves significant reduction in data loss.Article Discussions on Perturbed Quasi-Metric Spaces(Yokohama Publishing, 2025) Karapinar, ErdalThe main goal of this manuscript is to introduce the notion of perturbed quasi-metric spaces. Furthermore, it shall discuss the existence of basic fixed point theorems in the setting of perturbed quasi-metric spaces.Conference Object Citation - Scopus: 4Convolution Neural Network (cnn) Based Automatic Sorting of Cherries(Institute of Electrical and Electronics Engineers Inc., 2021) Park,H.; Khan,M.U.Cherries are spring fruits enriched with nutrients, and are easily available in food markets around the world. Due to their excess demand, many enterprises solely focused on their processing. Cherries are especially susceptible to pathological-, physiological-diseases and structural degradation due to their soft outer skin. The post-harvest life of the fruit is limited by various characteristics. The agricultural industry has also been at the forefront to get benefits from the advanced machine learning tools. This study presents an image processing-based system for sorting cherries using the convolutional neural network (CNN). For this study, Prunus avium L cherries of export quality, available in Turkey, tagged as ‘0900 Ziraat’, are used. Surprisingly, there exists no dataset for these cherries; hence, we developed our dataset. Through the proposed approach based upon U-Net, the binary classification accuracy of 99% is achieved. Clear identification is demonstrated by the test results of varying mixture ratios of good and bad cherries. It can therefore be said that for cherry sorting and grading, U-Net can be applied as a reliable and promising machine learning tool. ©2021 IEEEArticle Citation - WoS: 1Citation - Scopus: 1Outcomes of Transcatheter Aortic Valve Implantation in Patients With and Without Diabetes Mellitus(Soc Brasil Cirurgia Cardiovasc, 2024) Ayhan, Huseyin; Guney, Murat Can; Keles, Telat; Bozkurt, EnginIntroduction: Diabetes mellitus (DM) in patients undergoing cardiac transcatheter or surgical interventions usually is correlated with poor outcomes. Transcatheter aortic valve implantation (TAVI) has been developed as a therapy choice for inoperable, high-, or intermediate-risk surgical patients with severe aortic stenosis (AS). Objective: To evaluate the impact of DM and hemoglobin A1c (HbA1c) on outcomes and survival after TAVI. Methods: Five hundred and fifty-two symptomatic severe AS patients who underwent TAVI, of whom 164 (29.7%) had DM, were included in this retrospective study. Follow-up was performed after 30 days, six months, and annually. Results: The device success and risks of procedural-related complications were similar between patients with and without DM, except for acute kidney injury, which was more frequent in the DM group (2.4% vs. 0%, P=0.021). In-hospital and first-year mortality were similar between the groups (4.9% vs. 3.6%, P=0.490 and 15.0% vs. 11.2%, P=0.282, respectively). There was a statistical difference between HbA1c >= 6.5 and HbA1c <= 6.49 groups in total mortality (34.4% vs. 15.8%, P<0.001, respectively). The only independent predictors were Society of Thoracic Surgeons score (hazard ratio [HR] 1.28, 95% confidence interval [CI] 1.09-1.51; P=0.003) and HbA1c level >= 6.5 (HR 10.78, 95% CI 2.58-21.50; P=0.003) in multivariable logistic regression analysis. Conclusion: In this study, we conclude that DM was not correlated with an increased mortality risk or complication rates after TAVI. Also, it was shown that mortality was higher in patients with HbA1c >= 6.5, and it was an independent predictor for long-term mortality.Article Effectiveness of Boric Acid in Sepsis in Rats With Cecal Perforation(Springer Nature, 2025) Kurtipek, Ali Can; Dursun, Ali Dogan; Yigman, Zeynep; Ozdemir, Cagri; Kucuk, Aysegul; Gonullu, Ugur; Arslan, MustafaIntroduction and AimSepsis is a systemic inflammatory response that develops in the host against microorganisms, which results in end-organ damage. Boric acid (BA) has been shown to have immune modulatory effects in vitro and in animal studies. The aim of the study is to investigate the effects of high dose BA on lung and kidney tissues in rats with sepsis induced by the CLP method.Method28 rats were randomly divided into four groups: Group C (control group), Group BA, Group CLP (cecal ligation and puncture), and Group CLP + BA. Cecum was ligated below the ileocecal valve and punctured. BA was administered to the treatment groups at an intraperitoneal dose of 200 mg/kg, and at the end of 24 h, lung and kidney tissue samples were collected and evaluated for biochemical and histopathological parameters.ResultsHistopathologically, in kidney tissue, CLP + BA group showed significantly less peritubular capillary dilatation and brush border loss in the proximal tubule epithelium compared to the CLP group. In lung tissue, CLP + BA group had significantly less alveolar wall thickening compared to the CLP group. Biochemical analyses indicated that BA administration reduced oxidative stress in both renal and lung tissues.ConclusionWe found that intraperitoneal administration of high dose boric acid partially ameliorated the tissue damage in rats subjected to CLP induced sepsis. Further studies are needed regarding the dosage and application at different time points.Article Evaluating Anterior Segment Stability and Corneal Endothelium After Prolene Gonioscopy Assisted Transluminal Trabeculotomy (gatt) in Open-Angle Glaucoma(Springer, 2024) Aribas, Yavuz Kemal; Aktas, Zeynep; Ertop, MestanIntroduction This study investigates the short-term effects of prolene gonioscopy-assisted transluminal trabeculotomy (GATT) on anterior segment parameters and corneal endothelium in patients with open-angle glaucoma. Methods This retrospective study included 30 eyes from 30 patients who underwent GATT surgery. Demographic data, ophthalmological examination findings, and intraocular pressure (IOP) measurements using a Goldman applanation tonometer were recorded. Scheimpflug images were acquired at the pre-operative stage, as well as on the 1st day, 1st week, and 1st month postoperatively. Corneal endothelial cell counts were obtained via specular microscopy. Results The mean age of patients was 60.3 +/- 15.5 years. Anterior chamber depth and central corneal thickness increased on the 1st postoperative day (p:0.002, p < 0.001, respectively). Changes in anterior chamber depth values at the postoperative 1st week and 1st month compared to baseline were not statistically significant. Central corneal thickness decreased significantly at the 1st postoperative month compared to baseline (p:0.007). Corneal endothelial cell counts at the 1st month were comparable to baseline values (p:0.936). Conclusion Our findings reveal that prolene gonioscopy-assisted transluminal trabeculotomy induces temporary changes in anterior segment parameters but preserves corneal endothelial cell count within the first month, suggesting a promising profile for GATT in glaucoma management.Article Citation - WoS: 2Citation - Scopus: 2An Investigation of Recycled Rubber Composites Reinforced With Micro Glass Bubbles: an Experimental and Numerical Approach(Taylor & Francis Ltd, 2024) Kabakci, Gamze Cakir; Bayraktar, Emin; Aslan, OzgurRecycled rubber is widely used for its lightweight and cost-effective properties but often has limited mechanical strength, restricting its applications. This study enhances the mechanical performance of devulcanised recycled rubber by reinforcing it with micro glass bubbles (GBs) featuring a density of 0.65 g/cm(3) and an elastic modulus of 3.5 GPa, offering a high strength-to-density ratio. Uniaxial compression tests were conducted on samples with GB volume fractions of 5%, 10%, and 15%. Results were validated through finite element analysis (FEA) in ABAQUS/Standard, incorporating randomised GB distributions. A 2D representative volume element (RVE) with randomly distributed GBs was modelled, applying periodic boundary conditions to simplify the composite into an equivalent homogeneous material. Numerical simulations assessed the effects of GB diameters (30, 40, and 50 mu m) and inclusion size ranges (20-50 mu m and 10-60 mu m), finding minimal impact on results. The RVE, sized at 238 mu m, accurately represented macroscale composite behaviour. Stress-strain behaviour was analysed using average stress and strain tensors. The strong agreement between experimental and numerical results validates the proposed method, demonstrating its accuracy in predicting the mechanical behaviour of the reinforced composite material.Article Citation - WoS: 17Citation - Scopus: 24Optimization and Energy Analysis of a Novel Geothermal Heat Exchanger for Photovoltaic Panel Cooling(Pergamon-elsevier Science Ltd, 2021) Jafari, Rahim; Jafari, Rahim; Jafari, Rahim; Automotive Engineering; Automotive EngineeringElectrical energy and conversion efficiency of the photovoltaic (PV) solar panels are measured under standard test conditions in some microseconds at the room temperature (25 degrees C). It also is seen that the actual working conditions, on the other hand, with higher ambient temperature and continuous generated heat in the PV cells can lead to reduction in reduce their electricity generation and long-term sustainability. In the current work, the coolant (water + ethylene glycol) circulates between two heat exchangers; the minichannel heat exchanger is bounded to the PV cells and geothermal heat exchanger is buried underground, and it is set to remove the heat from PV cells to the ground. Six control factors of the geothermal cooling system are considered for the purpose of optimization using Taguchi design and main effect analysis. These parameters are pipe length, soil thermal conductivity, coolant flow rate, adjacent coil distance, pipe inner diameter and pipe thickness. The experimental results show that the average net electricity generation of the cooled PV panel is improved 9.8% compared to the PV panel without cooling system. However, with the same geothermal heat exchanger it drops to 6.2% as the cooled panel number is doubled. The simulation results reveal that the optimum configuration of the geothermal cooling system is capable of enhancing the net electricity generation of the twin cooled panels up to 11.6%. The LCOE of the optimized geothermal cooling system was calculated 0.089 euro/kWh versus the reference panel of 0.102 euro/kWh for the case study of 30 kW PV solar plant.Article Citation - Scopus: 5An Examination of the Relationships Between Nurses’ Team Work Attitudes, Conflicts With College and Job Satisfaction: An Example of a Public Hospital(Informa UK Ltd, 2022) Akyüz,F.; Tengilimoğlu,D.; Özkanan,A.; Akyüz,S.Nurses are one of the most important elements of the health system. In this study, it was aimed to determine the teamwork attitudes of nurses, their conflicts with their colleagues, their job satisfaction, to determine whether these variables differ according to the socio-demographic characteristics of the nurses, and to reveal the relationships between these variables. The data in the study were obtained from 253 nurses working in the Children’s Hospital of Ankara City Hospital using a questionnaire method. A significant relationship was found between the teamwork attitudes of the nurses, their colleagues, and their level of conflict and job satisfaction. © 2021 Taylor & Francis Group, LLC.Review Citation - Scopus: 7Ion Exchange Membranes for Reverse Electrodialysis (red) Applications - Recent Developments(Amirkabir University of Technology - Membrane Processes Research Laboratory, 2021) Eti,M.; Othman,N.H.; Guler,E.; Kabay,N.The innovative membrane-based technology called reverse electrodialysis (RED) is capable of producing electrical power from the controlled mixing of two aqueous streams of different salinity. There has been tremendous progress so far in the development of RED process in terms of system development, spacer design, membranes properties and operational conditions optimization. Among those, characteristics of the ion exchange membranes are found to be the critical element affecting the performances of RED process. In this respect, a brief overview of the latest developments in ion exchange membranes were presented in this review, focussing on their properties and performances in RED applications. The recent developments of nanocomposite and ion selective membranes, particularly pore filling ion exchange membranes due to their high performances and inexpensive fabrication cost were also summarized. Shortly, fouling problem for the ion exchange membranes employed in the RED system was mentioned. © 2021 Amirkabir University of Technology - Membrane Processes Research Laboratory. All rights reserved.
