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18β-Glycyrrhetinic Acid-Loaded Silver Nanoparticles Mitigate Neuroinflammation and Endoplasmic Reticulum Stress in the Brain Tissue of Diabetic Rats
(Mashhad University of Medical Sciences, 2026) Parlak, Secil Nazife; Yakut, Seda; Kara, Adem; Demir, Ozlem; Sebin, Saime Ozbek
Objective(s): Diabetes mellitus (DM) causes oxidative stress, neuroinflammation, and endoplasmic reticulum (ER) dysfunction that contribute to neurodegeneration. This study investigated the effects of 18 beta-glycyrrhetinic acid-loaded silver nanoparticles (18 beta-GA-AgNPs) on brain injury in diabetic rats. Materials and Methods: Fifty-six male Wistar rats were divided into eight groups: Sham, 18 beta-GA, AgNPs, 18 beta-GA-AgNPs, DM, DM+18 beta-GA, DM+AgNPs, and DM+18 beta-GA-AgNPs. Diabetes was induced by alloxan (120 mg/kg, IP), and treatments were administered orally for 14 days. Biochemical markers (MDA, GSH, SOD), histopathology, and expression of ER stress and apoptotic proteins (ATF6, IRE1, Caspase-3, BCL-2, CREB, TNF-alpha, and IL-1 beta) were evaluated. Results: The DM group exhibited significant increases in MDA, TNF-alpha, IL-1 beta, ATF6, and Caspase-3 with reduced GSH, SOD, and BCL-2, indicating oxidative stress, inflammation, apoptosis, and ER stress. In contrast, IRE1 levels remained unchanged in DM rats but showed a slight elevation in the AgNPs group. Treatment with 18 beta-GA-AgNPs markedly reduced MDA, TNF-alpha, IL-1 beta, ATF6, and Caspase-3, while restoring GSH, SOD, BCL-2, and CREB expression. Histopathological analysis confirmed neuronal apoptosis and perivascular and extracellular space enlargement in DM rats, whereas 18 beta-GA-AgNPs substantially attenuated these changes. Overall, 18 beta-GA-AgNPs provided synergistic neuroprotection by suppressing oxidative stress, inflammation, and ER stress while enhancing antioxidant and anti-apoptotic defenses. Conclusion: These findings suggest that 18 beta-GA-AgNPs may represent a promising therapeutic strategy against diabetes-associated neurodegeneration, although further long-term, ultrastructural, and sex-inclusive studies are warranted.
Citation - WoS: 5
Citation - Scopus: 4
3-Aminobenzamide Multifunctional Nanoparticles Enhances Anticancer Activity of Low-Dose Cisplatin Chemotherapy in Lung Adenocarcinoma
(Elsevier, 2024) Kaci, Fatma Necmiye; Daglioglu, Cenk
Chemotherapy is one of the main treatment methods for cancer patients, but its effectiveness is limited by drug resistance. Combining a chemotherapeutic agent with targeted molecular therapy may improve the curative effect of the chemotherapeutic agent. In this study, we investigate the efficacy of combining a 3-Aminobenzamide (3AB)-linked multifunctional platform with low-dose cisplatin chemotherapy aiming to modulate poly [ADP-ribose] polymerase 1 (PARP1) function in DNA repair to increase cytotoxic activity of the platinum-based cisplatin. The structure of the synthesized nanoplatforms was characterized by several physicochemical techniques, including dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and an in vitro pH-dependent release study. Cellular uptake experiments demonstrated preferentially targeted delivery of nanoparticles in lung carcinoma A549 cells, whereas the cellular uptake capacity was minimal in normal lung BEAS-2B cells. On the other hand, cytotoxicity experiments showed a reduction of cancer cell viability compared to free formulations. Furthermore, the combination treatment was examined by detecting the loss of mitochondrial membrane potential and the apoptotic cell population, confirming the treatment's functional involvement in apoptosis. Soft agar colony formation and cell invasion tests were also performed to detect the cancer cell's tumorigenic potential, confirming the synergistic effect of this combination in the reduction of tumorigenicity. Moreover, we analyzed the expression profiles of three candidate genes, which play important roles in cancer initiation, promotion and progression. Cell biology experiments indicated that this novel combination treatment possesses significant synergy between 3AB and low-dose cisplatin and is promising for development as an antitumor treatment for lung cancer.
Citation - WoS: 28
Citation - Scopus: 31
3-D Non-Linear Stress Analysis on the Adhesively Bonded Composite Joint Under Bending Moment
(Pergamon-Elsevier Science Ltd, 2014) Akpinar, Salih; Aydin, Murat Demir
This paper presents an approach to predict the three-dimensional effects (anti-clastic, free edge and bending-twisting coupling effects) and to assess the effects of the fiber orientation angle of the laminates on the stress distributions and the failure prediction in the Single Lap Composite Joints (SLJs) subjected to a bending moment via a 3-D non-linear finite element method. In the analysis, the composite adherends (AS4/3501-6) with five different fiber orientation angles ([901 +/- 45/0](2s), [0/90](4s), [45-45](4s), [0](16) and [90](16)) were assumed to behave as linearly elastic materials while the adhesive layer (FM 73) was assumed to be nonlinear. Also, the nonlinear geometric deformations of the SLJs were also taken into account. Consequently, it is seen that the state of stress in the vicinity of the free edge of the joint is fully three dimensional which has not been taken into account in any classical theory so far and the normal and shear stress distributions are extremely sensitive to this three-dimensional effects. From this aspect, the three-dimensional finite element analysis is a necessity for understanding explicitly the stress and failure states. Also, for both the adherends and the adhesive layer, the ply stacking sequence has a significant effect on the stress distribution and the failure. (C) 2014 Elsevier Ltd. All rights reserved.
Citation - Scopus: 2
3D Settlement Analysis of Underpinning Piles Under Raft Foundation Subjected to Nonuniform Vertical Loading
(Springer Verlag, 2018) Kalpakcı, V.; Ozturk, Ş.; Algin, H.; Burak Ekmen, A.
Existing rafts under the design loads sometimes experience excessive settlements or confront such a possibility in the future if the modified functionality of building is induced to increase the foundation loading. Differential settlement and deflection may also be observed in case of eccentric loading especially when these structures are built on soft soils. One of such precedents was observed in a silo structure used as a cement plant located in Douala, Cameroon. The structure that is founded on deep, soft clay with high ground water table rests on a raft supporting the storage tanks located at one side of the building conveying non-uniform loading to the existing raft. In one and a half year after completion of the construction, the silo structure had significantly settled and deflected. The underpinning pile remediation system allowing the continuity of cement production is applied from the outside of building using the rigidly connected protruding reinforced concrete section as a capping beam. In this study, the entire foundation system is numerically analyzed using the presented 3D finite element (FE) models. The back-analyses are used for the calibration concurring with the actual measurements of settlement and deflection at the site. The foundation systems with and without the underpinning piles are compared with each other to reveal how the remedial improvement is achieved by the presented underpinning pile system. © Springer Nature Switzerland AG 2018.
Ab’nin Döngüsel Ekonomi Politikası: Bir Patika Bağımlısı Kurumsal Değişim Süreci Analizi
(2022) Kaplan, Yılmaz
Döngüsel ekonomi (DE) modeli, ekonomi ve çevre arasında cereyan eden yapısal uyumsuzluk sebebi ile giderek istikrarsızlaşan lineer ekonomik modele karşı bir çare olarak ortaya çıkmıştır. Ancak küresel aktörler lineer ekonomik modelden döngüsel ekonomik modele tam anlamıyla kurumsal bir değişim gerçekleştirememişlerdir. Bu durumu sistemik bir şekilde açıklamak için araştırma nitel bir vaka çalışması olarak tasarlanmış ve Avrupa Birliği (AB) üzerine odaklanmıştır. Araştırma için veri AB’nin resmi dokümanlarından ve ilgi literatürden elde edilmiştir. Temel olarak AB’nin kurumsal rasyonalitesinin patika bağımlısı aşamalı bir kurumsal değişim stratejisi ürettiği bulgusuna ulaşılmıştır. AB döngüsel ekonomi politikasını halihazırda var olan ekonomi merkezli işlevsel sistemi ile uyumlu bir şekilde yürütmektedir ve bu sistem aşağıdan yukarıya doğru tasarlanmış bir kurumsal değişim stratejisini desteklemektedir. Buna ek olarak var olan kurumsal yapıya olan patika bağımlılığı geri dönüşümü döngüsel ekonominin diğer daha ileri prensipleri olan azaltma ve tekrar kullanmaya göre daha öncelikli hale getirmiştir. Verimsiz çevresel önlemleri içeren tarihsel bir öğrenme süreci ayrıca AB’yi döngüsel ekonomi politikasına geçilmesi konusunda teşvik etmiştir. Bu bulgular yeni kurumsalcı yaklaşımın aktörlerin hızlı ve keskin kurumsal değişimleri beklenmedik maliyetler yüzünden desteklemediği ve aktörlerin var olan kurumsal yapılarının onların kurumsal değişim çabalarına ciddi bir etkisinin olduğu savını desteklemektedir (patika bağımlılığı). Sonuç olarak, bu bakış açısından, aşamalı bir değişim, hızlı ve keskin bir değişime göre lineer ekonomik sistemin geleceği için daha olası bir seçenek olarak görünmektedir.
Citation - WoS: 22
Citation - Scopus: 25
Accessibility of Vaccination Centers in COVID-19 Outbreak Control: A GIS-Based Multi-Criteria Decision Making Approach
(MDPI, 2021) Alemdar, Kadir Diler; Kaya, Omer; Codur, Muhammed Yasin; Campisi, Tiziana; Tesoriere, Giovanni
The most important protective measure in the pandemic process is a vaccine. The logistics and administration of the vaccine are as important as its production. The increasing diffusion of electronic devices containing geo-referenced information generates a large production of spatial data that are essential for risk management and impact mitigation, especially in the case of disasters and pandemics. Given that vaccines will be administered to the majority of people, it is inevitable to establish vaccination centres outside hospitals. Site selection of vaccination centres is a major challenge for the health sector in metropolitan cities due to the dense population and high number of daily cases. A poor site selection process can cause many problems for the health sector, workforce, health workers, and patients. To overcome this, a three-step solution approach is proposed: (i) determining eight criteria using from the experience of the advisory committee, (ii) calculating criterion weights using Analytic Hierarchy Process (AHP), and performing spatial analysis of criteria using Geographic Information System (GIS), (iii) assigning potential vaccination centres by obtaining a suitability map and determining service areas. A case study is performed for Bagcilar, Istanbul district, using the proposed methodology. The results show that the suitable areas are grouped in three different areas of the district. The proposed methodology provides an opportunity to execute a scientific and strategic vaccination programme and to create a map of suitable vaccination centres for the countries.
Citation - WoS: 13
Citation - Scopus: 17
Accurate Estimation of T Year Extreme Wind Speeds by Considering Different Model Selection Criterions and Different Parameter Estimation Methods
(Pergamon-Elsevier Science Ltd, 2018) Tosunoglu, Fatih
Accurate estimation of extreme wind speeds for different return periods is necessary to avoid extensive costs or large damages. To achieve this aim, the probability distribution of the wind speed data should be well defined and its parameters should be more precisely estimated. In this study, the commonly used probability distributions, including Gamma, Generalized Extreme Value, Logistic, Lognormal, Normal and Weibull, are fitted to annual maximum wind speed data in Turkey. Parameters of the fitted distributions are estimated using method of moments (MOM), method of maximum likelihood (MLM) and method of probability weighted moments (PWMs). Based on various model selection criterions (Akaike Information Criterion, Bayesian Information criterion, Anderson-Darling, Cramer-von-Mises, and Kolmogorov-Smirnov tests), the Generalized Extreme Value and Logistic, which provided the best fit for 40% and 30% of the series, respectively, were mostly found to be the most suitable distributions. Additionally, the Lognormal, Normal and Gamma distributions showed the best fit for 15%, 10% and 5% of the series, respectively. Moreover, the MLM and PWMs provided better parameter estimations for 57% and 30% the best fitted distributions, respectively. Furthermore, wind speed quantiles with the standard errors in various return periods were estimated using the best fitted distributions. (C) 2018 Elsevier Ltd. All rights reserved.
Citation - WoS: 137
Citation - Scopus: 144
Acetylcholinesterase and Carbonic Anhydrase Inhibitory Properties of Novel Urea and Sulfamide Derivatives Incorporating Dopaminergic 2-Aminotetralin Scaffolds
(Pergamon-Elsevier Science Ltd, 2016) Ozgeris, Bunyamin; Goksu, Suleyman; Kose, Leyla Polat; Gulcin, Ilhami; Salmas, Ramin Ekhteiari; Durdagi, Serdar; Supuran, Claudiu T.
In the present study a series of urea and sulfamide compounds incorporating the tetralin scaffolds were synthesized and evaluated for their acetylcholinesterase (AChE), human carbonic anhydrase (CA, EC 4.2.1.1) isoenzyme I, and II (hCA I and hCA II) inhibitory properties. The urea and their sulfamide analogs were synthesized from the reactions of 2-aminotetralins with N,N-dimethylcarbamoyl chloride and N,N-dimethylsulfamoyl chloride, followed by conversion to the corresponding phenols via O-demethylation with BBr3. The novel urea and sulfamide derivatives were tested for inhibition of hCA I, II and AChE enzymes. These derivatives exhibited excellent inhibitory effects, in the low nanomolar range, with K-i values of 2.61-3.69 nM against hCA I, 1.64-2.80 nM against hCA II, and in the range of 0.45-1.74 nM against AChE. In silico techniques such as, atomistic molecular dynamics (MD) and molecular docking simulations, were used to understand the scenario of the inhibition mechanism upon approaching of the ligands into the active site of the target enzymes. In light of the experimental and computational results, crucial amino acids playing a role in the stabilization of the enzyme-inhibitor adducts were identified. (C) 2016 Elsevier Ltd. All rights reserved.
Citation - WoS: 10
Citation - Scopus: 11
Acgc: Adaptive Chrominance Gamma Correction for Low-Light Image Enhancement
(Academic Press Inc. Elsevier Science, 2025) Severoglu, N.; Demir, Y.; Kaplan, N. H.; Kucuk, S.
Capturing high-quality images becomes challenging in low-light conditions, often resulting in underexposed and blurry images. Only a few works can address these problems simultaneously. This paper presents a low- light image enhancement scheme based on the Y-I-Q transform and bilateral filter in least squares, named ACGC. The method involves applying a pre-correction to the input image, followed by the Y-I-Q transform. The obtained Y component is separated into its low and high-frequency layers. Local gamma correction is applied to the low-frequency layers, followed by contrast limited adaptive histogram equalization (CLAHE), and these layers are added up to produce an enhanced Y component. The remaining I and Q components are also enhanced with local gamma correction to provide images with amore natural color. Finally, the inverse Y-I-Q transform is employed to create the enhanced image. The experimental results demonstrate that the proposed approach yields superior visual quality and more natural colors compared to the state-of-the-art methods.
Citation - WoS: 31
Citation - Scopus: 32
Acute and Chronic Effects of Aerobic Exercise on Serum Irisin, Adropin, and Cholesterol Levels in the Winter Season: Indoor Training Versus Outdoor Training
(Wolters Kluwer Medknow Publications, 2020) Ozbay, Serhat; Ulupinar, Suleyman; Sebin, Engin; Altinkaynak, Konca
The aim of this study is to investigate the acute and chronic effects of aerobic training performed indoors and outdoors on irisin, adropin, and cholesterol levels in winter. Thirty-two healthy males participated in this study. Participants were divided into two groups: outdoor group (n = 16) and indoor group (n = 16). They then performed 40-min aerobic running exercises 4 days/week for 18 weeks. The outdoor group trained at -5 degrees C-5 degrees C environmental temperature, while the indoor group trained at 21 degrees C-25 degrees C. Blood samples were collected before and after the 18-week training period and immediately after the first training. The results showed that single aerobic exercise induced minimal increase in serum irisin concentrations in both groups. In addition, irisin levels did not change in the outdoor group but significantly decreased in the indoor group after the 18-week training period. Aerobic exercise had no acute or chronic effects on serum adropin levels in the indoor group. However, the aerobic training caused a decrease in adropin levels chronically, but there was no acute effect after single aerobic exercise in the outdoor group. Furthermore, there was no acute effect on high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, and total cholesterol after single aerobic exercise in both groups. However, after the 18-week training period, there was a significant increase in HDL-C levels in both groups. Moreover, the increase in HDL-C in the outdoor group was higher than in the indoor group. Thus, this study provides evidence for the beneficial chronic effects of aerobic exercise and cold on HDL-C levels as well as the beneficial acute effects on irisin concentrations.
Citation - WoS: 7
Citation - Scopus: 7
The Acute Effects of Hip Thrust and Glute Bridge Exercises with Different Loads on Sprint Performance and Horizontal Force-Velocity Profile in Adolescent Soccer Players: A Post-Activation Performance Enhancement Approach
(Wiley, 2025) Cabuk, Salih; Ince, Izzet
This study examines the acute effects of post-activation performance enhancement (PAPE) with different loads (84% and 60% 1-RM) and exercises (hip thrust; HT and glute bridge; GB) on sprint performance (SP) and horizontal force-velocity (HF-V) profile components in adolescent male soccer players. The participants were randomly assigned to three groups: hip thrust group (HTG; n = 13), glute bridge group (GBG; n = 13), and control group (CG; n = 14). Sprint tests at distances of 10, 20, and 30 m were conducted pre-PAPE and post-PAPE protocols with a 7 min rest period. HTG and GBG executed HT and GB exercises at 84% and 60% of their 1-RM loads. Hedge's g was computed to assess within-group (pre-PAPE vs. post-PAPE) comparisons (Within-ES) and between-group (post-PAPE protocols) comparisons (Between-ES). PAPE protocols at 84% and 60% 1-RM loads demonstrated moderate effects on F0rel, Pmaxrel, FVslope, and DRF and small effects on V0, RFmax, and S20m in both HTG and GBG. Conversely, the CG exhibited trivial effects across parameters. Compared to the HTG 84% 1-RM protocol, the GBG 84% 1-RM protocol showed small effects on V0 and S10m. The HTG 60% 1-RM protocol had a small effect on RFmax compared to both GBG 84% and 60% 1-RM protocols. Both HTG and GBG 84% and 60% 1-RM protocols demonstrated small effects on S30m compared to the CG. These findings suggest that GB exercises may offer a viable alternative to HT exercises for eliciting PAPE effects, particularly in enhancing SP and related mechanics in adolescent soccer players.
Citation - WoS: 1
Citation - Scopus: 1
Acute Effects of Nordic Hamstring Exercise on Hamstring Stiffness: A Randomised Controlled Trial
(MDPI, 2025) Yagiz, Gokhan; Monleon, Cristina; Akaras, Esedullah; Adanir, Sena; Liebana, Encarnacion
Background: This study aimed to examine the immediate effects of the Nordic Hamstring Exercise (NHE) on the stiffness of the biceps femoris (BF) and semitendinosus (ST) muscles. Methods: This parallel-group randomised controlled trial followed CONSORT 2025 guidelines. Twenty-four physically active adults (16 females, 8 males) were randomly assigned to an NHE group (n = 12) or a control group (n = 12) using 1:1 gender-stratified randomisation. The NHE group performed 3 sets of 10 repetitions of the NHE, while the control group remained inactive. Muscle stiffness of the BF and ST was assessed pre- and post-intervention using the MyotonPro device. Results: No significant overall changes in hamstring stiffness were observed within or between groups (p > 0.05). Within the NHE group, the ST tended to increase in stiffness (11.25 N/m, p = 0.057), while the BF showed a small, non-significant reduction (-12.00 N/m, p = 0.696). The difference in changes between BF and ST was significant (p = 0.039). Independent of group allocation, males demonstrated significantly higher baseline stiffness than females for BF (258.13 vs. 195.81 N/m, p < 0.001) and for ST (247.88 vs. 174.00 N/m, p = 0.003). Regression analysis showed that only height predicted the change in ST stiffness after NHE (R = 0.625, R-2 = 0.39, p = 0.030). Conclusions: A single NHE session did not alter overall hamstring stiffness but produced opposite, muscle-specific effects. More research with larger, uniform samples is needed to confirm these findings.
Citation - WoS: 3
Citation - Scopus: 4
Acute Effects of Three Different Stretching Techniques on Hamstring Flexibility in Professional Football Players
(Gdansk Univ Physical Education & Sport, 2023) Erol, Erkan; Yildiz, Ramazan; Yildiz, Aye; Dogan, Fatih Emre; Elbasan, Buelent
Introduction: Hamstring injuries are common in physically active people and athletes. Lack of hamstring flexibility is the one of the most important characteristics of hamstring injuries in athletes. The aim of this study was to investigate effects of three different stretching techniques on hamstring flexibility in professional football players. Materials and Methods: Fifty-five male football players between the ages of 18-20 years old were involved in the study. The participants were divided into 3 groups: static stretching, neuromobilization and Mulligan traction straight leg raise (TSLR), respectively. Each participant's dominant lower extremity was assessed with a straight leg raise test (SLR) using a goniometer before and after the intervention. Results: There was a significant difference in the SLR range of motion before and after the intervention in all groups. There was no difference in the range of SLR between the groups at the beginning and at the end. However, the increase in the SLR range of motion was significantly higher in the Mulligan TSLR group. Conclusions: It was concluded that all 3 stretching techniques are effective in increasing hamstring flexibility in football players. However, the Mulligan TSLR technique could provide a greater increase in the range of motion than other techniques.
Adaptation and Psychometric Evaluation of the Evidence-Based Practice Mentoring Scale into Turkish
(Ataturk Universitesi, 2025) Erden, Y.; Ulupınar, F.; Uludağ, E.
Objective: This study aimed to adapt the Evidence-Based Practice Mentorship Scale (EBP- Mentorship Scale) into Turkish and to evaluate its psychometric properties among Turkish nurses. Methods: This methodological study was conducted with 152 nurses between October 2022 and May 2023. The EBP-Mentorship Scale was translated into Turkish, and its content and construct validity were assessed. Confirmatory factor analysis (CFA) was performed to validate the factor structure. Reliability was evaluated using Cronbach’s alpha, Pearson’s correlation, and intra-class correlation coefficients (ICC). Results: The Turkish version of the EBP-Mentorship Scale retained the original 8 items and 1-factor structure. CFA results indicated a good model fit (χ2/df 0.90, GFI > 0.90). The scale demonstrated high internal consistency (Cronbach’s alpha = 0.94) and strong test-retest reliability (r = 0.956, p < .01; ICC = 0.997). The average variance extracted (AVE = 0.535) and composite reliability (CR = 0.899) values were sufficient, indicating good convergent validity. Conclusion: The Turkish version of the EBP-Mentorship Scale is a reliable and valid tool for assessing EBP mentorship among Turkish nurses. Its use can enhance the implementation and evaluation of EBP mentoring programs in nursing practice. © 2025, Ataturk Universitesi. All rights reserved.
Citation - WoS: 1
Adaptation Levels and Expectations of Students with Disabilities in Physical Education and Sports Departments of Universities
(Ankara University, Fac Educational Sciences, 2019) Namli, Sevinc; Suveren, Sibel
This research aims to determine the adaptations and expectations of the students with disabilities, who study in the physical education and sports departments, to their deparments. The research, which is composed of explanatory sequential design out of the mixed approach designs and in which quantitative and qualitative approaches are used together, were made with the participation of all the students with disabilities studying in physical education and sports departments of 21 universities in Turkey during 2015-2016 academic year. 71 students including 27 with visual impairments, 9 with hearing impairments and 38 with physically impairments participated in the quantitative section of the research. 11 students including 4 with visually impairments, 3 with hearing impairments and 4 with physically impairments participated in the qualitative section. "Adaptation Scale of Students with Disabilities Studying in Physical Education and Sports Departments" and "Semi-structured Interview Form" were used as data collection tools. While the participants with visually impairments and physically impairments emphasized the issue of organizing the physical areas and problems in the practical lessons, the participants with hearing impairments were found to have problems in theoretical lessons. It was determined that the students with disabilities have common expectations, such as instructors sparing more time for them during the lessons.
Citation - WoS: 4
Citation - Scopus: 4
Adaptation of Symbolic Discrete Control Synthesis for Energy-Efficient Multi-Pocket Milling
(MDPI, 2024) Caska, Serkan; Ozbaltan, Mete
In engineering, cost minimization, especially in Computer Numerical Control (CNC) machining like pocket milling, is crucial. Existing tool path definition software often lacks optimization, particularly at critical starting and ending points. This study optimizes CNC machine tool paths for energy-efficient multi-pocket milling, utilizing the Symbolic Discrete Control Synthesis (SDCS) method for formal correctness. In our work, the tool path generation is formulated as a traveling salesman problem. We introduce a modeling framework to adapt SDCS to multi-pocket-milling processes, aiming to enhance precision and efficiency for potential cost savings, including energy and time, in engineering applications. This study reports experimental and comparative results, where comparative evaluations were made using metaheuristic algorithms. Our proposed approach improves CNC machining processes for multi-pocket milling. We experimentally evaluate our control algorithms and demonstrate and validate our approach through case studies.
Citation - Scopus: 6
Adaptive Consensus-Based Formation Control of Fixed-Wing MUAVs
(Institute of Electrical and Electronics Engineers Inc., 2017) Guzey, M.
Neural Network-based adaptive consensus control is designed in this paper for a team of fixed-wing unmanned aerial vehicles. The group of unmanned aerial vehicles moving at fixed altitudes are controlled through a novel adaptive formation controller to drive them to a pre-defined formation shape. The theoretical conjecture is verified by simulation results. © 2017 IEEE.
Citation - WoS: 1
Citation - Scopus: 1
Adaptive Event Triggered Control of Nonholonomic Mobile Robots
(Springer International Publishing AG, 2021) Guzey, Mehmet
In this paper, the design of adaptive regulation control of mobile robots in the presence of uncertain robot dynamics and with event-based feedback is presented. Two-layer neural networks (NN) are utilized to represent the uncertain nonlinear dynamics of the mobile robots, which is subsequently employed to generate the control torque with event-sampled measurement update. Relaxing the perfect velocity tracking assumption, control torque is designed to minimize the velocity tracking error, by explicitly taking into account the dynamics of the robot. The Lyapunov's stability method is utilized to develop an event-sampling condition and to demonstrate the regulation performance of the mobile robot. Finally, simulation results are presented to verify theoretical claims and to demonstrate the reduction in the computations with event-sampled control execution.
Citation - Scopus: 1
Adaptive Event-Triggered Regulation Control of Nonholonomic Mobile Robots
(Springer, 2020) Guzey, M.
In this chapter, the design of adaptive-regulation control of mobile robots (MR) in the presence of uncertain MR dynamics with event-based feedback is provided. Two layer neural-networks (NN) are utilized to represent the uncertain dynamics of the MR which is subsequently employed to generate the control torque with event-sampled measurement update. By relaxing the perfect velocity tracking assumption, control torque is developed to minimize the velocity tracking errors, by explicitly taking into account the dynamics of the MR. The Lyapunov’s method is utilized to develop an event-sampling condition and to demonstrate the regulation error performance of the MR. At the end of the chapter, simulation results are given to verify our theoretical claims. © Springer Nature Singapore Pte Ltd. 2020.
Citation - Scopus: 37
An Adaptive Fractional Controller Design for Automatic Voltage Regulator System: Sigmoid-Based Fractional-Order PID Controller
(Springer Science and Business Media Deutschland GmbH, 2024) Şahin, A.K.; Cavdar, B.; Ayas, M.S.
The primary objective of a power system is to provide safe and reliable electrical energy to consumers. This objective is achieved by maintaining the stability of the power system, a multifaceted concept that can be divided into three distinct classes. The focus of this study is on one of these classes, voltage stability. A critical component in maintaining voltage stability is the automatic voltage regulator (AVR) system of synchronous generators. In this paper, a novel control method, the sigmoid-based fractional-order PID (SFOPID), is introduced with the aim of improving the dynamic response and the robustness of the AVR system. The dandelion optimizer (DO), a successful optimization algorithm, is used to optimize the parameters of the proposed SFOPID control strategy. The optimization process for the DO-SFOPID control strategy includes a variety of objective functions, including error-based metrics such as integral of absolute error, integral of squared error, integral of time absolute error, and integral of time squared error, in addition to the user-defined Zwee Lee Gaing’s metric. The effectiveness of the DO-SFOPID control technique on the AVR system has been rigorously investigated through a series of tests and analyses, including aspects such as time domain, robustness, frequency domain, and evaluation of nonlinearity effects. The simulation results are compared between the proposed DO-SFOPID control technique and the fractional-order PID (FOPID) and sigmoid-based PID (SPID) control techniques, both of which have been tuned using different metaheuristic algorithms that have gained significant recognition in recent years. As a result of these comparative analyses, the superiority of the DO-SFOPID control technique is confirmed as it shows an improved performance with respect to the other control techniques. Furthermore, the performance of the proposed DO-SFOPID control technique is validated within an experimental setup for the AVR system. The simulation results show that the proposed DO-SFOPID control technique is highly successful in terms of stability and robustness. In summary, this study provides comprehensive evidence supporting the effectiveness and superiority of the DO-SFOPID control technique on the AVR system through both simulation and experimental results. © The Author(s) 2024.

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