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Now showing 1 - 10 of 303
  • Article
    Citation - Scopus: 3
    Complete Characterization of a Class of Permutation Trinomials in Characteristic Five
    (Springer, 2024) Grassl,M.; Özbudak,F.; Özkaya,B.; Temür,B.G.
    In this paper, we address an open problem posed by Bai and Xia in [2]. We study polynomials of the form f(x)=x4q+1+λ1x5q+λ2xq+4 over the finite field F5k, which are not quasi-multiplicative equivalent to any of the known permutation polynomials in the literature. We find necessary and sufficient conditions on λ1,λ2∈F5k so that f(x) is a permutation monomial, binomial, or trinomial of F52k. © The Author(s) 2024.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Which Is Better To Predict Erectile Dysfunction and Male Sexual Function in the Context of Metabolic Syndrome: Triglyceride-Glucose Index or Visceral Adiposity Index?: a Retrospective Cross-Sectional Study
    (Springer, 2024) Bolat, Mustafa Suat; Bolat, Ipek Akalin; Dundar, Cihad; Asci, Ramazan
    PurposeMany factors influence male sexual function, including metabolic disorders such as metabolic syndrome (MetS). We aimed to investigate the effects of two metabolic indices, the triglyceride-glucose (TyG) index and the visceral adiposity index (VAI), on male sexual function.MethodsA total of 400 men having sexual dysfunction were included. Anthropological data, comorbidities were recorded. Serum total testosterone, prolactin, and estradiol levels were recorded. Sex-specific VAI was calculated using the [(WC/39.68) + (1.88xMI)] x (TG/1.03) x (1.31/HDL) formula and using Ln (fasting triglycerides) x (fasting glucose)/2] formula, TyG index was calculated. Turkish-validated 15-item long-form of the International Index of Erectile Dysfunction (IIEF) questionnaire and male sexual health questionnaire (MSHQ) were used for erectile function and ejaculatory function, respectively. The ROC analysis was used to evaluate the predictive abilities of TyG and VAI cut-off values for ED risk.ResultsA higher TyG index and VAI were associated with an increased risk of ED. The presence of MetS further worsened sexual function, with lower scores in sexual satisfaction, orgasm, desire, and general satisfaction. The TyG index and VAI showed similar predictive abilities for ED. Patients with MetS had worse ejaculation quality compared to those without MetS.ConclusionsThese findings highlight the potential of the TyG index and VAI as convenient tools for predicting and assessing sexual dysfunction in men, particularly in the context of metabolic disorders. Early detection and intervention for metabolic syndrome and insulin resistance may help to mitigate their negative impact on male sexual function.
  • Article
    Citation - WoS: 33
    Citation - Scopus: 37
    Discrete Sizing Optimization of Steel Trusses Under Multiple Displacement Constraints and Load Cases Using Guided Stochastic Search Technique
    (Springer, 2015) Azad, S. Kazemzadeh; Hasancebi, O.
    The guided stochastic search (GSS) is a computationally efficient design optimization technique, which is originally developed for discrete sizing optimization problems of steel trusses with a single displacement constraint under a single load case. The present study aims to investigate the GSS in a more general class of truss sizing optimization problems subject to multiple displacement constraints and load cases. To this end, enhancements of the GSS are proposed in the form of two alternative approaches that enable the technique to deal with multiple displacement/load cases. The first approach implements a methodology in which the most critical displacement direction is considered only when guiding the search process. The second approach, however, takes into account the cumulative effect of all the critical displacement directions in the course of optimization. Advantage of the integrated force method of structural analysis is also utilized for further reduction of the computational effort in these approaches. The proposed enhancements of GSS are investigated and compared with some selected techniques of design optimization through six truss structures that are sized for minimum weight. The numerical results reveal that both enhancements generally provide promising solutions with an insignificant computational effort.
  • 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, Mestan
    Introduction 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: 1
    Citation - Scopus: 1
    Growth and Optical Properties of (na0.5bi0.5< (x=0.25) Single Crystal: a Potential Candidate for Optoelectronic Devices
    (Springer, 2024) Guler, I.; Isik, M.; Gasanly, N.
    Double tungstates (DT) and double molybdates (DM) have significant importance because of their optoelectronic applications. Regarding the importance of DT and DM, we investigated experimentally structural and optical properties of (Na0.5Bi0.5)(Mo1-xWx)O-4 (x = 0.25) crystal that belongs to the NaBi-DT and DM crystals group. Czochralski method was used to grow the single crystals. The structure of the crystal was identified using X-ray diffraction (XRD) measurements. Two sharp peaks associated with tetragonal crystal structure appeared in the pattern. Vibrational modes of the studied crystal were obtained from the Raman experiments. By the help of the Fourier transform infrared spectrophotometer (FTIR) measurements, infrared transmittance spectrum of the studied compound was recorded. Band gap energy wase found around 3.04 eV using two methods, Tauc and derivative analysis, based on transmission spectrum. Based on the analysis of absorption coefficient, Urbach energy was obtained as 0.22 eV. The revealed structural and optical properties of the crystal indicated that the material may be a candidate for optoelectronic devices in which NaBi(MoO4)(2) and NaBi(WO4)(2) materials are utilized.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Structural Design Optimization of Multi-Layer Spherical Pressure Vessels: a Metaheuristic Approach
    (Springer, 2019) Akis, Tolga; Azad, Saeid Kazemzadeh
    This study addresses the optimum design problem of multi-layer spherical pressure vessels based on von Mises yield criterion. In order to compute the structural responses under internal pressure, analytical solutions for one-, two-, and three-layer spherical pressure vessels are provided. A population-based metaheuristic algorithm is reformulated for optimum material selection as well as thickness optimization of multi-layer spherical pressure vessels. Furthermore, in order to enhance the computational efficiency of the optimization algorithm, upper bound strategy is also integrated with the algorithm for reducing the total number of structural response evaluations during the optimization iterations. The performance of the algorithm is investigated through weight and cost minimization of one-, two- and three-layer spherical pressure vessels and the results are presented in detail. The obtained numerical results, based on different internal pressures as well as vessel sizes, indicate the usefulness and efficiency of the employed methodology in optimum design of multi-layer spherical pressure vessels.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 14
    Fuzzy Logic Model To Estimate Seasonal Pseudo Steady State Chlorophyll-A Concentrations in Reservoirs
    (Springer, 2004) Soyupak, S; Chen, DG
    A fuzzy logic model is developed to estimate pseudo steady state chlorophyll-a concentrations in a very large and deep dam reservoir, namely Keban Dam Reservoir, which is also highly spatial and temporal variable. The estimation power of the developed fuzzy logic model was tested by comparing its performance with that from the classical multiple regression model. The data include chlorophyll-a concentrations in Keban lake as a response variable, as well as several water quality variables such as PO4 phosphorus, NO3 nitrogen, alkalinity, suspended solids concentration, pH, water temperature, electrical conductivity, dissolved oxygen concentration and Secchi depth as independent environmental variables. Because of the complex nature of the studied water body, as well as non-significant functional relationships among the water quality variables to the chlorophyll-a concentration, an initial analysis is conducted to select the most important variables that can be used in estimating the chlorophyll-a concentrations within the studied water body. Following the outcomes from this initial analysis, the fuzzy logic model is developed to estimate the chlorophyll-a concentrations and the advantages of this new model is demonstrated in model fitting over the traditional multiple regression method.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 7
    Artificial Intelligence in Education: a Text Mining-Based Review of the Past 56 Years
    (Springer, 2025) Ekin, C.C.; Cantekin, Ö.F.; Polat, E.; Hopcan, S.
    Artificial Intelligence in Education (AIED) is a broad and multifarious area of study that spans across various academic fields. Due to the high numbers of studies in this field, it seems too challenging to analyze all of them in depth in a single study. Additionally, there is a lack of research that provides a comprehensive overview of the main trends and topics in AIED. This study, hence, aims to fill this gap by using text mining techniques to examine how artificial intelligence (AI)-related research in education has evolved over time. To this end, a total of 11,027 articles indexed by the Scopus database in the field of education between 1967 and 2023 were examined. Based on the findings, there has been a significant increase in AIED since 2014, covering 73% of the publications. Over the past three decades, AIED research has increasingly concentrated on engineering student populations and conference proceedings. Notably, AI solutions are extensively employed in education, with a strong focus on personalization, assessment, and evaluation. They also play a prominent role in research review processes, such as text mining and topic modeling for summarizing research findings. The findings contribute to the field, enhancing our understanding of the patterns of AI’s integration into education and offering guidance for prospective research endeavors. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.
  • Article
    Citation - WoS: 26
    Citation - Scopus: 33
    Cyberloafing Behaviors Among University Students: Their Relationships With Positive and Negative Affect
    (Springer, 2023) Metin-Orta, Irem; Demirtepe-Saygili, Dilek
    With the technological advances, the use of digital devices, such as laptops, tablets, or smartphones in the educational setting has become prevalent among young people. Accordingly, there has been an increased concern among scholars on students' in-class Internet use for personal purposes; namely, 'cyberloafing'. Considerable research has demonstrated the adverse effects of in-class Internet use on students' learning environment and academic performance. The present study particularly investigates the relationship between cyberloafing behaviors and positive and negative affect among university students. It examines five different online activities including sharing, shopping, real-time updating, accessing online content, and gaming/gambling separately to gain greater insight into students' cyberloafing behaviors. The sample consisted of 267 undergraduate students who filled out questionnaires measuring cyberloafing behaviors, positive and negative affect, and demographical information including the use of the Internet and mobile technologies. The initial analyses showed that male students had higher scores in shopping, accessing online content, and gaming/gambling than females. The latent variable analysis revealed that among different activities of cyberloafing, accessing online content and gaming/gambling were positively correlated with positive affect, while sharing was positively associated with negative affect among students. The findings emphasize the importance of evaluating cyberloafing as a part of students' psychological well-being rather than a variable merely related to academic achievement. The findings of the study also enlighten researchers and educators in developing appropriate policies and interventions to manage misuse of the Internet in class.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 7
    The Effect of Social Media Usage, Appearance-Related Social Media Pressure and Body Mass Index on Body Appreciation of Cosmetic Procedure Patients
    (Springer, 2023) Sonmez, Mehmet; Esiyok, Elif
    Background The number of cosmetic procedures has increased in recent years. Social media use and its effects on plastic surgery decisions are among the most widely discussed topics. This study aimed to test a research model that explores the relationship between social media usage frequency, appearance-related social media pressure, and body mass index (BMI) on the body appreciation of patients undergoing cosmetic procedures, and to evaluate their clinical impacts. Methods In total, 136 participants were included in this study, which met and exceeded the sample size requirement. The questionnaire was designed by using reliable scales and demographic data. Partial least squares structural equation modeling was used to test the hypothesized research model. Results The mean age of the participants was 35 years, and 70% had normal BMI scores. Among them, 59.6% underwent invasive procedures and 40.4% underwent minimally invasive procedures. BMI negatively affected body appreciation (beta = 0.199, p < 0.05). Social media did not have a significant effect on appearance-related social media pressure (beta = 0.001, p > 0.05). Appearance-related social media pressure negatively affected body appreciation (beta = - 0.280. p > 0.05). Conclusion Social media is not only an information source but also creates pressure on appearance. Therefore, plastic surgeons should use social media and consider the psychology of patients during their communication.