Yıldız Technical University Research Information System
Not a member yet
91324 research outputs found
Sort by
Future anxiety mediates the relationship between organ donation and transplantation knowledge and health-related quality of life.
No full textStrategic site selection methodology for small modular reactors: A case study in Türkiye
No full textSelecting the optimal site for Small Modular Reactors (SMRs) ensures operational efficiency and safety and aligns with growing energy demands and environmental goals. Given the unique challenges of climate change and the need for sustainable energy solutions, this study's innovative approach provides critical insights for making informed decisions that balance economic, environmental, and social factors. This study introduces a novel hybrid multi-criteria decision-making (MCDM) approach for selecting optimal sites for SMR in Türkiye. The proposed methodology integrates Picture Fuzzy SWARA (PiF-SWARA) and Picture Fuzzy WASPAS (PiF-WASPAS) techniques to address site selection's complexities by evaluating criteria weights and alternative scores. PiF-SWARA is employed to determine the relative importance of five main criteria and 28 sub-criteria, providing a nuanced understanding of each criterion's impact. Subsequently, PiF-WASPAS ranks the alternative sites based on these weighted criteria. This approach ensures a robust evaluation by accommodating various uncertainties inherent in the decision-making process. The case study applied to Türkiye demonstrates the effectiveness of this method in identifying the most suitable locations for SMRs, highlighting its potential to advance the strategic planning of nuclear energy infrastructure. The study provides valuable insights for policymakers and stakeholders involved in energy planning and development
The scale for adult education trainers’ digital technology use levels: a validity and reliability study
No full textIn the context of lifelong learning, it is crucial for adult educators and trainers tounderstand and learn adult learning theories in adult education settings. Furthermore, flexibility and adaptability to the ever-changing learning environment in atechnological context, as well as strategies for making real-world connections withdifferent teaching methods, are critical. Moreover, it is noteworthy that trainers inadult education often lack formal teacher training, despite the essential skills theyshould possess. The aim of this study is to develop a valid and reliable measurementtool to determine the level of integration of digital technologies into the educationprocess of trainers who provide education specifically for adult learners.. For thispurpose, data was collected from 665 trainers employed at a training institute forlifelong learning affiliated with the Istanbul Metropolitan Municipality. We used theLawshe technique, exploratory factor analysis, and confirmatory factor analysis forthe validity and reliability stages of the scale. We also computed the Cronbach alphaand composite reliability coefficients. The validity and reliability studies led to thedevelopment of a scale with 22 items and four factors, which measures trainers’level of digital technology integration in the education and training process. TheCronbach Alpha values of the scale range between 0.828 and 0.939 for each of thefour dimensions. We tested the obtained scale with CFA and found that the structure falls within the acceptable fit values. The scale is named the Adult EducationTrainers’ Levels of Digital Technology Use in Education Scale. The scale consistsof four sub-dimensions: active participation and alternative learning environments,assessment and evaluation, professional development, and interactive, dynamiccontent. We hope to use the scale, particularly in studies with adult instructors intraining institutions, to assess the extent of digital technology integration in trainers’educational processes.</p
On Solvability Of One Boundary Value Problem For Laplace Equation in Banach-Hardy Classes
No full textIn this paper we consider the Dirichlet problem for the Laplace equation in Hardy classes generated by an additive-invariant Banach function space on the unit circle. It is shown that the classical Dirichlet problem for the Laplace equation has a unique solution for every boundary function from the considered space. It is considered a boundary problem for the Laplace equation with oblique derivatives in the Hardy classes generated by separable subspaces of rearrangement-invariant spaces in which the infinitely differentiable functions are dense. Noetherness of this problem is established and the index of this problem is calculated
Chirped and chirp-free optical soliton solutions for stochastic long-short wave resonant equations with multiplicative white noise
No full textThis article introduces a novel governing model characterized by stochastic long-short wave resonant equations with multiplicative white noise applicable in fields such as telecommunications and climate modeling. The study aims to explore chirped and chirp-free soliton solutions within this framework. Using Jacobi's elliptic function method as our primary methodology, we have successfully derived various soliton solutions, including solitary waves, singular solitons, and dark and bright soliton forms which can be relevant in optical communication and nonlinear optics. Significantly, our analysis has facilitated the extraction of both chirped and chirp-free solutions applicable to the model, marking a notable advancement in soliton research. Introducing this governing model is a pioneering endeavor in the field, distinguished by its ability to model the resonance interaction between long and short waves under the influence of multiplicative white noise. This aspect holds profound implications for the understanding and application of wave dynamics in stochastic environments such as in meteorology and fluid dynamics. To underscore our findings, the manuscript includes 3D and 2D graphical representations, effectively illustrating the impact of white noise on the wave profiles of the derived solitons. Our study broadens the theoretical landscape of soliton solutions and presents a significant step forward in practically examining wave resonance phenomena under stochastic conditions
Adaptive Stochastic Gradient Descent (SGD) for erratic datasets
No full textStochastic Gradient Descent (SGD) is a highly efficient optimization algorithm, particularly well suited for large datasets due to its incremental parameter updates. In this study, we apply SGD to a simple linear classifier using logistic regression, a widely used method for binary classification tasks. Unlike traditional batch Gradient Descent (GD), which processes the entire dataset simultaneously, SGD offers enhanced scalability and performance for streaming and large-scale data. Our experiments reveal that SGD outperforms GD across multiple performance metrics, achieving 45.83% accuracy compared to GD's 41.67 %, and excelling in precision (60 % vs. 45.45 %), recall (100 % vs. 60 %), and F1-score (100 % vs. 62 %). Additionally, SGD achieves 99.99 % of Principal Component Analysis (PCA) accuracy, slightly surpassing GD's 99.92 %. These results highlight SGD's superior efficiency and flexibility for large-scale data environments, driven by its ability to balance precision and recall effectively. To further enhance SGD's robustness, the proposed method incorporates adaptive learning rates, momentum, and logistic regression, addressing traditional GD drawbacks. These modifications improve the algorithm's stability, convergence behavior, and applicability to complex, large-scale optimization tasks where standard GD often struggles, making SGD a highly effective solution for challenging data-driven scenarios
Performance Analysis of Wired and Wireless Optical Communication Systems in the Sea of Marmara Marmara Denizi nde Kablolu ve Kablosuz Optik Haberlesme Sistemlerinin Performans Analizi
No full textIn this study, submarine cable and wireless optical communication systems between Büyükada and Yalova are analyzed using the OptiSystem 7.0 simulation program. In the submarine investigation, fiber optic cable and wireless optical communication channel (OWC channel) are used. A Wavelength Division Multiplexing (WDM) design is implemented for both systems. The transmission distance for the submarine optical communication system is determined using the Google Earth application. Transmitter power levels of 0,5,10,15, and 20 dBm are evaluated for both the submarine fiber optic and wireless optical communication systems. The best performance is observed at 10 dBm for the submarine fiber optic communication system and 20 dBm for the OWC system. Data rate, which is among thecritical parameters, is assessed at values of 0.5,1,5,10, and 15 Gbit/s. System performance is evaluated based on key indicators of reliability and accuracy, including the maximum Q-factor obtained from the Bit Error Rate (BER) analyzer and eye diagram analyses. The results from this study provide valuable insights for optimizing optical communication systems used in the Marmara Sea region
Portable Control Unit and Internet-Based Wireless Communication System Integrated with Left Ventricular Assist Devices Sol Ventrik l Destek Pompalarina Entegre Portatif Kontrol nitesi ve Internet Tabanli Kablosuz Iletisim Sistemi
No full textLeft Ventricular Assist Devices (LVADs) are a treatment option that provides long-term mechanical circulatory support for patients with end-stage heart failure. However, the current LVAD control units do not allow remote monitoring of patient data or medical intervention when necessary. In this study, a portable control unit was developed that enables real- time monitoring of the patient (pulse, blood pressure) and pump (flow, rotational speed, current, and battery capacity) data in a remote and wireless environment through a designed website, provides alerts in emergency situations, and allows healthcare professionals to adjust the pump speed in real-time via the website. In tests conducted using two previously developed technologies (LVAD and Hybrid Mock Circuit), it was concluded that the developed portable unit has competitive clinical potential, and it was decided to proceed to in vivo (animal testing) performance tests
