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Article Citation - WoS: 1Citation - Scopus: 2Controlling Heterogeneous Structure of Smooth Breaks in Panel Unit Root and Cointegration Testing(Springer, 2023) Omay, Tolga; Iren, PerihanThis study aims to show the consequences of a restrictive homogeneity assumption of frequency in heterogeneous panel unit root and cointegration testing with Flexible Fourier Form. For this purpose, we use a simple panel unit root and residual based cointegration test with Flexible Fourier Form in a heterogeneous frequency setting using a bootstrap algorithm. The power of the test statistics and empirical analysis results indicate that failing to take into account a heterogeneous frequency may lead to misleading inferences, thereby leading to misspecified tests and erroneous conclusions concerning the stochastic behavior of the data in the panel sample.Article Citation - WoS: 8Citation - Scopus: 11Proposing a novel mixed-reality framework for basic design and its hybrid evaluation using linkography and interviews(Springer, 2022) Cindioglu, Hasane Ceren; Gursel Dino, Ipek; Surer, ElifImmersive Virtual Environments (IVEs), particularly Mixed-Reality (MR) technologies, continue to have an increasing impact on design processes and design education. This study focuses on MR's potentials in Basic Design (BD) education and its influence on novice designers' design thinking abilities. In this study, through a newly developed MR-based design framework, DesignMR, a comparative analysis between design processes in MR and the physical environment is presented. A hybrid evaluation methodology is used in the context of three-dimensional (3D) BD tasks through two sets of protocol studies: Linkography and exit interviews. Linkography is a method to analyze the design process based on detecting design moves and their links with each other. In this study, linkographic analyses point to an increase in critical moves and link index values in MR as compared to the physical environment for all participants. This indicates that MR can trigger improved creativity, design productivity, and design exploration by idea generation. Exit interviews highlighted the positive impact of DesignMR on the motivation, work efficiency, and 3D perception of the participants. Further research will be pursued for improved hand gestures to increase the effectiveness of object interaction.Article Citation - WoS: 1Citation - Scopus: 2Predictors of E-Democracy Applicability in Turkish K-12 Schools(Springer, 2022) Sendag, Serkan; Toker, Sacip; Uredi, Lutfi; Islim, Omer FarukToday, the COVID-19 pandemic has paved the way for a more democratic climate in K-12 schools. Administrators and teachers have had to seek out new ways through which to interact. This raises two questions; "What about the quality of interaction and participation in decision-making?" and "Which factors affect the level of participation in decision-making?" The aim of the current research is to determine the factors that predict the applicability level of e-democracy (i.e., "reporting and declaring opinions" and "decision-making") in K-12 schools. An associational research design was used in order to attain the main goal of the study, with Discriminant Function Analysis (DFA) technique used to analyze the factors predicting the applicability level of e-democracy. Data were collected from a total of 765 inservice K-12 teachers through a questionnaire developed by the researchers. DFA results showed "motivation to participate," "the level of participatory democracy in the country," and higher levels of the "use of Twitter" as the significant determinants of different levels of e-democracy application. Moreover, the results also indicated that those participants with the belief of e-democracy's applicability at the decision-making level found the "motivation level of stakeholders" to be the most critical. Their level of Twitter use was higher. They also believed that the level of participatory democracy in the country was at a higher level. Another result of the DFA pointed to "security and ethical issues," and lower levels of the "use of Twitter" as factors differentiating the group believing that e-democracy can be applicable with reporting and the declaration of opinions to administrators from the other groups. The discussions highlighted the critical role of participation level in e-democracy within K-12 schools.Article The Relationship between Perinatal Grief and Spiritual Well-Being in Women Experiencing Termination due to Fetal Anomaly in Türkiye(Springer, 2025) Sari, Tugba; Gemicioglu, Sirin Harkin; Harkin Gemicioğlu, ŞirinPregnancy termination is a significant event in women's lives and can be considered a traumatic experience that can assess grief reactions. Couples who accept the decision to have a medical termination due to fetal anomaly face not only anxiety and feelings of loss, but also difficulties adapting to and coping with the termination process. This study aims to examine the relationship between perinatal grief and spiritual well-being in women who experience termination due to fetal anomaly. The study sample consisted of 256 women who had undergone termination during pregnancy. Data were analyzed using descriptive statistics (percentage, mean, standard deviation), the Mann-Whitney U test for independent samples, the Kruskal-Wallis test, Spearman correlation, and multiple linear regression analyses. The participants' mean score on the Perinatal Grief Scale was 112.87 +/- 15.04. The spiritual well-being scale subscale scores were 56.13 +/- 8.69 for the transcendence subscale, 25.27 +/- 2.94 for the harmony with nature subscale, and 26.58 +/- 3.18 for the anomie subscale. The correlation between the mean scores of the scales indicated that perinatal grief level was positively and significantly related to both the transcendence (r = 0.454; p < .001) and harmony with nature (r = 0.571; p < .001) subscales, while there was a strong negative correlation between perinatal grief and the anomie subscale (r = -0.762; p < .001). In conclusion, the study results indicate that perinatal grief is significantly related to various dimensions of spiritual well-being. These findings support the idea that supporting spiritual well-being in individuals experiencing perinatal grief can strengthen psychosocial adjustment.Article Citation - WoS: 5Citation - Scopus: 7On the Classification of Modulation Schemes Using Higher Order Statistics and Support Vector Machines(Springer, 2022) Coruk, Remziye Busra; Gokdogan, Bengisu Yalcinkaya; Benzaghta, Mohamed; Kara, AliThe recognition of modulation schemes in military and civilian applications is a major task for intelligent receiving systems. Various Automatic Modulation Classification (AMC) algorithms have been developed for this purpose in the literature. However, classification with low computational complexity as well as reasonable processing time is still a challenge. In this paper, a feature-based approach along with various classifiers is employed based on statistical features as well as higher-order moments and cumulants. An over-the-air (OTA) recorded dataset consisting of four analog and ten digital modulation schemes are used for testing the proposed method at 0-20 dB SNR. The overall accuracy for quadratic Support Vector Machine (SVM) is found to be as high as 98% at 10 dB. The comparison of the results with other AMC papers published in the literature indicates that the proposed method present higher accuracy, especially for realistic channel induced OTA dataset.Article Citation - Scopus: 1An Enhanced Guided Stochastic Search With Repair Deceleration Mechanism for Very High-Dimensional Optimization Problems of Steel Double-Layer Grids(Springer, 2024) Azad, Saeid Kazemzadeh; Aminbakhsh, Saman; Gandomi, Amir H.Finding reasonably good solutions using a fewer number of objective function evaluations has long been recognized as a good attribute of an optimization algorithm. This becomes more important, especially when dealing with very high-dimensional optimization problems, since contemporary algorithms often need a high number of iterations to converge. Furthermore, the excessive computational effort required to handle the large number of design variables involved in the optimization of large-scale steel double-layer grids with complex configurations is perceived as the main challenge for contemporary structural optimization techniques. This paper aims to enhance the convergence properties of the standard guided stochastic search (GSS) algorithm to handle computationally expensive and very high-dimensional optimization problems of steel double-layer grids. To this end, a repair deceleration mechanism (RDM) is proposed, and its efficiency is evaluated through challenging test examples of steel double-layer grids. First, parameter tuning based on rigorous analyses of two preliminary test instances is performed. Next, the usefulness of the proposed RDM is further investigated through two very high-dimensional instances of steel double-layer grids, namely a 21,212-member free-form double-layer grid, and a 25,514-member double-layer multi-dome, with 21,212 and 25,514 design variables, respectively. The obtained numerical results indicate that the proposed RDM can significantly enhance the convergence rate of the GSS algorithm, rendering it an efficient tool to handle very high-dimensional sizing optimization problems.Article Citation - WoS: 21Citation - Scopus: 16Assessment of Shock Models for a Particular Class of Intershock Time Distributions(Springer, 2022) Kus, Coskun; Tuncel, Altan; Eryilmaz, SerkanIn this paper, delta and extreme shock models and a mixed shock model which combines delta-shock and extreme shock models are studied. In particular, the interarrival times between successive shocks are assumed to belong to a class of matrix-exponential distributions which is larger than the class of phase-type distributions. The Laplace -Stieltjes transforms of the systems' lifetimes are obtained in a matrix form. Survival functions of the systems are approximated based on the Laplace-Stieltjes transforms. The results are applied for the reliability evaluation of a certain repairable system consisting of two components.Book Part Citation - Scopus: 6Cannabinoids as Prospective Anti-Cancer Drugs: Mechanism of Action in Healthy and Cancer Cells(Springer, 2023) Boyacıoğlu,Ö.; Korkusuz,P.Endogenous and exogenous cannabinoids modulate many physiological and pathological processes by binding classical cannabinoid receptors 1 (CB1) or 2 (CB2) or non-cannabinoid receptors. Cannabinoids are known to exert antiproliferative, apoptotic, anti-migratory and anti-invasive effect on cancer cells by inducing or inhibiting various signaling cascades. In this chapter, we specifically emphasize the latest research works about the alterations in endocannabinoid system (ECS) components in malignancies and cancer cell proliferation, migration, invasion, angiogenesis, autophagy, and death by cannabinoid administration, emphasizing their mechanism of action, and give a future perspective for clinical use. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Article Polysulfur Copolymer as a Support Material for the Preparation of a Novel Multifunctional Photocatalytic Composite Material(Springer, 2025) Kesimal, Busra; Guner, Zuhal Vanli; Cihaner, Atilla; Kaya, Murat; Vanli Guner, ZuhalOne-step addition of magnetic nanoparticles and titanium dioxide nanoparticles into polysulfur copolymer as cheap and available support was reported for the first time to prepare the magnetically separable heterogeneous catalyst, PolyS-MNP-TiO2. The photocatalytic activities of the PolyS-MNP-TiO2 composite material and its constituents were examined in the methylene blue (MB) degradation, textile-based wastewater simulant, exposed to solar light. Detailed characterization of the catalysts was performed with SEM, TEM, and EDX measurements. The photocatalytic activity of the resulting composite was figured out in the removal of methylene blue dye by using a solar simulator. Significantly, the as-prepared PolyS-MNP-TiO2 exhibits exceptional photocatalytic activity and total degradation of dye molecules was achieved in 60 min. Additionally, the prepared novel photocatalyst showed enhanced stability and reusability due to the magnetic behavior of the composite material and the same portion of catalyst was used in five successive tries without apparent loss in catalytic activity by eliminating long and work-loaded processes like filtration and centrifugation.Article Citation - WoS: 2Citation - Scopus: 8The progress of 21st-century skills throughout instructional design projects: a quasi-experimental comparison of rapid prototyping and dick and carey models(Springer, 2022) Toker, SacipThis study investigates the association between instructional design projects and 21st-Century skills. A causal-comparative design was utilised. The participants were 85 computer education and instructional technology department students who registered for a core instructional design course. The participants are divided into two groups: Rapid prototyping model - RPM (n = 47) and Dick and Carey model - DCM (n = 38). The RPM group were assigned to character education topics and developed e-books; the DCM group were assigned to several college-level topics included and developed digital materials. The DCM group significantly improved their life and career skills compared to the RPM group. The results show that the participants demonstrated an increase in time management skills and a decrease in cooperation process skills in both groups.
