WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
Browse
212 results
Search Results
Article Refocus on Planning and Positive Refocusing Mediate the Relationship Between Cognitive Flexibility and Psychological Resilience(Springer, 2026) Mungan, Özlem; Torun Yazihan, NaksidilCognitive flexibility is one of the most important indicators of mental health and is a cognitive process at the heart of psychological resilience. The more cognitively flexible individuals are, the more likely they are to use adaptive emotion regulation strategies, which in turn increases their psychological resilience, according to the results of the current study. This study highlights the value of fostering cognitive flexibility and adaptive emotion regulation strategies to promote psychological resilience, and provides practical insights for practitioners. For future studies, training programmes designed to improve cognitive flexibility may have downstream benefits for emotion regulation and resilience-for example, cognitive behavioural therapy, rational-emotional therapy and mindfulness-based interventions, which are known to improve cognitive flexibility, may be particularly effective in promoting adaptive emotional responses.Article Improved Arithmetic Efficiency in TFHE Through Gate-Level Optimizations(Springer, 2025) Tasel, Faris Serdar; Saran, Ayse NurdanFully homomorphic encryption (FHE) enables computations to be performed directly on encrypted data without decryption, offering a promising solution for privacy-preserving applications, such as secure cloud computing, confidential machine learning, and encrypted analytics. However, one major drawback of FHE is the high computational cost of homomorphic operations, which slows down real-world implementations, making them impractical. This paper explores the implementation of arithmetic operations within the framework of Torus FHE (TFHE) and demonstrates the construction of gate-level optimization for fundamental operations such as addition, subtraction, negation, comparison, and multiplication on fixed-point numbers. Our work emphasizes optimizing arithmetic logic to reduce the number of bootstrapping operations, a critical factor in improving computational efficiency. Furthermore, we investigate the error rates associated with the proposed operations, providing valuable insight into their accuracy and practical applicability. This study contributes to developing more efficient and reliable arithmetic logic for privacy-preserving computations in FHE systems. The experimental results indicate that the proposed optimizations yield speedups of up to 2.27x for addition/subtraction, 3.55x for comparison, and 1.80x for multiplication operations.Article Comparative Analysis of Impedance Matching Techniques in Wireless Power Transfer Efficiency: A Focus on Resonant, Adaptive, and Hybrid Approaches(Springer, 2025) Hatem, Sude; Kurt, ErolWireless power transfer (WPT) efficiency is highly dependent on impedance matching; however, comparative analyses of matching techniques under dy namic operating conditions remain limited. This study presents a systematic evaluation of three impedance matching approaches, namely resonant, adaptive, and hybrid, via theoretical modeling and numerical simulations. The results prove that adaptive impedance matching maintains stable efficiency (90.0% +/- 0.9%) in load variations (20-100 Omega ), coil misalignment (0<bold>degrees</bold>-30<bold>degrees</bold>), and transmission distances (0.1-1 cm), with minimal fluctuations. In contrast, resonant matching shows the best efficiency (i.e., 95%) under ideal conditions (10 MHz, 0<bold>degrees</bold> misalignment, 50 Omega load) but degrades rapidly to <50% under deviation conditions (e.g., 30 misalignment or 1 cm distance). The hybrid solution yields a balanced compromise that maintaining 85-92% efficiency in larger operating ranges. Quantitative metrics-the fluctuation rate (adaptive: 0.07 vs. resonant: 0.15) and stability index (adaptive: 102 vs. resonant: 20)-exhibit adaptive matching's superior dynamic performance. These find ings present practical advice on selecting impedance matching techniques in real WPTapplications, such as electric vehicle charging and medical implants, where stability under variability is paramount.Article Generalized Chebyshev Acceleration(Springer, 2025) Gokgoz, NurgulWe use generalized Chebyshev polynomials, associated with the root system \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$A_2$$\end{document}, to provide a new semi-iterative method for accelerating simple iterative methods for solving linear systems. We apply this semi-iterative method to the Jacobi method, and give an example. We also analyze the efficiency of our method with sparse matrices of large dimension. There are certain restrictions but the resulting acceleration is rather high.Article Effects of Receiver Diversity on Bit Error Rate of Underwater Optical Wireless Communication Systems in Weak Oceanic Turbulence(Springer, 2025) Gokce, Muhsin Caner; Baykal, Yahya; Ata, YalcinThe receiver spatial diversity techniques are employed in underwater optical wireless communication (OWC) systems to mitigate oceanic turbulence, improving the bit error rate performance. In this paper, we consider an OWC system employing a binary phase-shift keying (BPSK) modulated Gaussian beam at the transmitter and employing receiver spatial diversity at the receiver. The techniques for receiver spatial diversity systems considered in the study are selection combining (SC), equal gain combining (EGC), and the maximum ratio combining (MRC). The bit error rate (BER) performance of the OWC system operating in weak oceanic turbulence is investigated by calculating the Gaussian beam's turbulence-induced scintillation index and the received optical intensity. It is found that the receiver spatial diversity techniques, especially EGC and MRC, are very effective for reducing the BER of an OWC system in weak oceanic turbulence. Furthermore, the BER performance of the underwater OWC system sees an improvement with an increase in the number of photodetectors or a decrease in the level of oceanic turbulence. Moreover, an improvement in the photodetector responsivity or a reduction in the system's noise factor contributes to achieving a favorable BER performance.Article Citation - WoS: 2Citation - Scopus: 1Interfacial Behavior and Diffusion Mechanisms of Bni-2 Brazing on Titanium Alloy: Experimental and Molecular Dynamics Insights(Springer, 2025) Goynuk, Tansu; Esen, Ziya; Karakaya, IshakContextJoining titanium alloys, particularly Ti-6Al-4V, is crucial in aerospace applications where reliable, high-performance joints are needed. Brazing offers an effective solution, enabling the joining of dissimilar materials without melting the base metals. However, optimizing the wetting and diffusion behavior of filler metals remains a challenge. This study investigates the high-temperature interaction between BNi-2 filler alloy and Ti-6Al-4V. Boron, the primary melting point depressant in BNi-2, was examined due to its small atomic size and interstitial diffusion mechanism. Elevated temperatures led to improved wetting, reflected by decreased contact angles. Both wetting angles and boron diffusion coefficients were obtained through molecular dynamics simulations and experimental measurements, showing reasonable correlation. These results provide valuable insight into interfacial mechanisms and support further optimization of brazing parameters.MethodsMolecular dynamics simulations were performed using LAMMPS to analyze the temperature-dependent wetting behavior of molten BNi-2 on Ti-6Al-4V and track atomic-scale diffusion. Initial atomic configurations were modeled and simulated under various conditions. Trajectory data were analyzed using OVITO for structural evolution. Boron diffusion was evaluated by calculating mean square displacement from LAMMPS outputs. These values were used to derive diffusion coefficients and activation energies. Parallel experiments were conducted to assess wetting angles and diffusion behavior, and simulation results were compared with experimental data. The consistency between both approaches highlights the reliability of the modeling framework in capturing essential mechanisms during the brazing process.Article Supply Chain Network Design Focused on Financial Measures and Performance Metrics: a Systematic Literature Review(Springer, 2025) Abbasi, Sina; Sicakyuz, CigdemThrough an extensive literature review, this study determines which metrics and measures are relevant for supply chain (SC) performance. We reviewed several universal papers published between 2012 and 2023. A selection of review papers was made according to the methods, contribution, and scope for measuring SC performance metrics and measures. By reviewing the literature, this survey prepares benchmarks and approaches for determining SC performance from a financial viewpoint. As core financial measures of SC performance, we investigation looked at inventory turnover ratios, logistics costs, and cash flows expressed as return on investment (ROI), return on equity (ROE), return on asset (ROA), profit margins, assets/liabilities, and working capital. Additionally, the study determined that key non-financial measures of SC performance are customer satisfaction, delivery performance, quality services, improved relationships, and competitive advantages. According to the study, the appropriate approaches for assessing SC performance are financial and non-financial measures. Using the same approach, measures, and metrics at all SC nodes is essential to determine SC performance appropriately. Moreover, research is needed to identify the benefits and issues preventing SC measurements and performance across different industries.Article Citation - WoS: 1Citation - Scopus: 1Prediction of the Profile of a Vertical Air-Entraining Vortex(Springer, 2025) Al-Hakeem, Yasameen Mansoor A.; Tastan, Kerem; Yildirim, NevzatAir-core vortices occurring at intakes cause efficiency losses, vibrations, operational difficulties, and erosion at affiliated water-conveying structures. Air-core vortices are in the forms of non-air entraining vortex (air-core vortex in suspension) and air-entraining vortex. The profile of an air-core vortex is considered to be one of the main characteristics of the vortex. There are available semi-empirical formulas for the profile of a vertical non-air entraining vortex (air-core vortex in suspension) occurring at a vertically-flowing downward intake. However, there is no available developed formula relating to the profile of a vertical air-entraining vortex occurring at a vertically-flowing downward intake because the height, radii, and other physical quantities of the imaginary section of the air-entraining vortex downstream of the intake entrance are not measurable. Therefore, the profile of a vertical air-entraining vortex needs to be predicted. In the present study, by modifying the available formula relating to the profile of a non-air-entraining vortex and incorporating available test data, a practical methodology is developed for predicting the profile of a vertical air-entraining vortex. This study provides a practical formula and a chart to determine the necessary parameters to predict the profile of a vertical air-entraining vortex. The validation of the proposed methodology is examined and checked with available test data relating to the profile of a vertical air-entraining vortex occurring at a vertically-flowing downward intake. The results of the present study are in good agreement with available test data relating to the profile of vertical air-entraining vortices (the coefficient of determination is between 0.976 and 0.995).Article Citation - WoS: 5Citation - Scopus: 4Comparative Landslide Susceptibility Mapping Using Local Inventories: a Case Study From Trabzon, Türkiye(Springer, 2025) Ozturk, SevkiThis paper presents a novel approach to landslide susceptibility mapping by integrating two landslide inventories prepared by different national agencies of T & uuml;rkiye (MTA and AFAD) in the Trabzon region. By leveraging these different inventories, the study aims to offer a more comprehensive understanding of landslide risks, addressing limitations in previous susceptibility models that typically rely on single inventory sources. Employing the frequency ratio method, the paper generates susceptibility maps from each database to examine the influence of landslides across various environmental factors. Additionally, an Analytical Hierarchy Process (AHP)-based map, incorporating environmental characteristics, literature, and expert opinions, is developed to provide a third perspective, independent of historical landslide data. The results indicate that AHP model classifies approximately 19.20% of the study area as very high and high susceptibility. In contrast, the MTA and AFAD models assign only 12.40% and 8.80% to high and very high categories, with most areas falling into low to moderate susceptibility. Comparisons with the Global Landslide Hazard Map further highlight the strengths and limitations of localized versus global assessments. This study contributes to the field by demonstrating the benefits of a dual-inventory approach, enhancing the precision of landslide susceptibility maps and providing valuable insights for disaster risk management and sustainable land-use planning.Article Citation - WoS: 1Citation - Scopus: 1Fractional Systems With Multi-Parameters Fractional Derivatives(Springer, 2025) Muslih, S.I.; Agrawal, O.P.; Baleanu, D.Recently, a generalization of fractional variational formulations in terms of multiparameter fractional derivatives was introduced by Agrawal and Muslih. This treatment can be used to obtain the Lagrangian and Hamiltonian equations of motion. In this paper, we also extend our work to introduce the generalization of the formulation for constrained mechanical systems containing multi-parameter fractional derivatives. Three examples for regular and constrained fractional systems are analyzed. © The Author(s) 2025.