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Conference Object Citation - WoS: 7Citation - Scopus: 7Effect of Hardening Models on Different Ductile Fracture Criteria in Sheet Metal Forming(Springer France, 2016) Dizaji, Shahram Abbasnejad; Darendeliler, Haluk; Kaftanoglu, BilginPrediction of the fracture is one of the challenging issues which gains attention in sheet metal forming as numerical analyses are being extensively used to simulate the process. To have better results in predicting the sheet metal fracture, appropriate ductile fracture criterion (DFC), yield criterion and hardening rule should be chosen. In this study, the effects of different hardening models namely isotropic, kinematic and combined hardening rules on the various uncoupled ductile fracture criteria are investigated using experimental and numerical methods. Five different ductile fracture criteria are implemented to a finite element code by the user subroutines. The criterion constants of DFCs are obtained by the related experimental tests. The in-plane principle strains obtained by the finite element analyses for different DFCs are compared with the experimental results. Also, the experimental results are used to evaluate the principle strain values calculated by the finite element analysis for different combinations of DFCs and hardening rules. It is shown that some DFCs give better predictions if the appropriate hardening model is employed.Article Citation - WoS: 55Citation - Scopus: 61Encoding the Future: Successful Processing of Intentions Engages Predictive Brain Networks(Academic Press inc Elsevier Science, 2010) Poppenk, J.; Moscovitch, M.; McIntosh, A. R.; Ozcelik, E.; Craik, F. I. M.Evidence from cognitive, patient and neuroimaging research indicates that "remembering to remember" intentions, i.e., prospective memory (PM) retrieval, requires both general memory systems involving the medial temporal lobes and an executive system involving rostral PFC (BA 10). However, it is not known how prospective memories are initially formed. Using fMRI, we investigated whether brain activity during encoding Of future intentions and present actions differentially predicted later memory for those same intentions (PM) and actions (retrospective memory). We identified two significant patterns of neural activity: a network linked to overall memory and another linked specifically to PM. While overall memory success was predicted by temporal lobe activations that included the hippocampus, PM success was also uniquely predicted by activations in additional regions, including left rostrolateral PFC and the right parahippocampal gyrus. This finding extends the role of these structures to the formation of individual intentions. It also provides the first evidence that PM encoding, like PM retrieval, is supported by both a common episodic memory network and an executive network specifically recruited by future-oriented processing. (C) 2009 Elsevier Inc. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 3Insomnia Severity Predicts Psychiatric Symptoms: a Cross-Sectional Study Investigating the Partial Mediations of Worry and Rumination(Routledge Journals, Taylor & Francis Ltd, 2024) Turkarslan, Kutlu Kagan; Cinarbas, Deniz CanelObjective: Insomnia as a disorder on its own or as a symptom of other mental disorders can lead to significant distress and lower quality of life. By exacerbating negative affect and emotion dysregulation, poor sleep and insomnia can contribute to the initiation and maintenance of mental disorders. The aim of this cross-sectional study was to investigate the relationship between insomnia severity and overall psychiatric symptoms (anxiety, depression, obsessive-compulsive symptoms, somatization, phobic anxiety, hostility, interpersonal sensitivity, paranoid ideation, and psychoticism), and the mediational roles of worry and rumination in this relationship. Method: The data was collected from a community sample of 1444 participants (females 69.39%, M-age=27.95, SD=9.37) who completed self-report measures of insomnia severity, worry, rumination, and psychiatric symptoms. The mediational roles of worry and rumination were tested with mediation analysis using the PROCESS Macro. Results: It was found that insomnia severity (beta=0.20, p<.001) significantly predicted psychiatric symptoms directly and via worry and rumination (beta=0.33, p<.001), meaning that worry and rumination partially mediated the relationship between insomnia severity and psychiatric symptoms. The findings were similar after controlling for smoking status, daily screen time, coffee consumption in the evening, weekly exercise frequency, and pre-sleep screen time. Conclusions: Interventions targeting the reduction of insomnia severity and maladaptive emotion regulation strategies (e.g., worry and rumination), as well as the enhancement of adaptive emotion regulation strategies (e.g., positive refocusing and mindfulness), may alleviate the adverse effects of insomnia on psychiatric symptoms.Article Çin’in Uluslararası Kimlik Trilemması: Gelişmekte Olan Ülke, Bölgesel Güç Ya Da Büyük Güç?(2019) Yıldırım, Nilgün EliküçükÇin dış politikasında sabit bir ülke kimliğinden ziyade aynı anda farklı birçok kimlik benimsemektedir. Çin Üçüncü Dünya ile ilişkilerinde hala gelişmekte olan ülke kimliğini kullanırken, periferisinde bölgesel güç rolünü oynamaktadır. Uluslararası alanda ise büyük güçlere atfedilen uluslararası sorumluluk prensibini üstlenmektedir. Bu bağlamda Çin’in gelişmekte olan ülke mi, bölgesel güç mü ya da küresel anlamda büyük güç mü olduğu konusunda kesinlik yoktur. Çin’in dış politikada birden çok kimliğe aynı anda bürünmesi, uluslararası ilişkiler akademisi tarafından tartışılan küresel kimliklerin bir ya da birkaçının benimsenmesi sonucudur. Uluslararası kimlik tartışmalarının odak noktası ise düşük profil stratejisinin temel taşlarından biri olan “juebu dangtou” yani asla “lider olma/liderlik yapma” prensibidir. Bu çalışma da, Çin akademisindeki uluslararası kimlik tartışmalarını, gelişmekte olan ülke, bölgesel güç ve büyük güç kimliği olarak üç kategoride ele alacağım. Çalışmanın temel önermesi, Xi Jinping’in “başarı için mücadele” stratejisinin şekillenmesinde akademideki kimlik tartışmalarının etkili olduğudur. Ayrıca bu tartışmalar Çin’in hangi siyasi coğrafya üzerinden etki alanı yaratmak isteyeceğini gözlemlemek için de oldukça yararlıdır.Article Citation - WoS: 8Citation - Scopus: 9A New Approach To the Existence and Uniqueness of Solutions for A Class of Nonlinear Q-Fractional Boundary Value Problems(Institute of Applied Mathematics of Baku State University, 2025) Karapinar, E.; Sevinik-Adiguzel, R.; Aksoy, U.; Erhan, I. M.The object of this study is a boundary value problem associated with a q-difference equation of fractional order. The existence and uniqueness of a solution in the case of multi-point boundary conditions is studied from the viewpoint of fixed point theory. An integral equation equivalent to the boundary value problem is derived and the fixed points of the related integral operator are investigated by using a contractive condition involving a comparison function. The Ulam-Hyers stability of the problem is also discussed. Theoretical results are followed by a particular example.Conference Object Citation - Scopus: 25A Comparison of Stream Processing Frameworks(Institute of Electrical and Electronics Engineers Inc., 2017) Karakaya,Z.; Yazici,A.; Alayyoub,M.This study compares the performance of Big Data Stream Processing frameworks including Apache Spark, Flink, and Storm. Also, it measures the resource usage and performance scalability of the frameworks against a varying number of cluster sizes. It has been observed that, Flink outperforms both Spark and Storm under equal constraints. However, Spark can be optimized to provide the higher throughput than Flink with the cost of higher latency. © 2017 IEEE.Article Citation - WoS: 29Citation - Scopus: 31Composition-tuned band gap energy and refractive index in GaSxSe1-x layered mixed crystals(Elsevier Science Sa, 2017) Isik, Mehmet; Gasanly, NizamiTransmission and reflection measurements on GaSxSe1-x mixed crystals (0 <= x <= 1) were carried out in the 400-1000 nm spectral range. Band gap energies of the studied crystals were obtained using the derivative spectra of transmittance and reflectance. The compositional dependence of band gap energy revealed that as sulfur (selenium) composition is increased (decreased) in the mixed crystals, band gap energy increases quadratically from 1.99 eV (GaSe) to 2.55 eV (GaS). Spectral dependencies of refractive indices of the mixed crystals were plotted using the reflectance spectra. It was observed that refractive index decreases nearly in a linear behavior with increasing band gap energy for GaSxSe1-x mixed crystals. Moreover, the composition ratio of the mixed crystals was obtained from the energy dispersive spectroscopy measurements. The atomic compositions of the studied crystals are well-matched with composition x increasing from 0 to 1 by intervals of 0.25. (C) 2016 Elsevier B.V. All rights reserved.Conference Object Citation - Scopus: 9A Layered Security Architecture for Corporate 802.11 Wireless Networks(Institute of Electrical and Electronics Engineers Inc., 2004) Erten,Y.M.; Tomur,E.In this study we have investigated the security aspects of wireless local area networks and discussed the weaknesses associated with various conventional 802.11 security protocols such as WEP and 802.1x. We propose an architecture to control access to corporate 802.11 wireless networks, based on the privileges and location of users, using the tested wired network components such as VPNs and Firewalls. The presented architecture reduces the security risks in enterprise level deployment of wireless LANs.Article Citation - WoS: 3Citation - Scopus: 4A New Class of Generalized Contraction Using p-functions in Ordered Metric Spaces(Sciendo, 2015) Amor, Sana Hadj; Karapinar, Erdal; Kumam, PoomIn this paper, we introduced and studied a new class of mappings in ordered metric spaces that is inspired from the concept of a P-function introduced in Chaipunya et. al. [10]. With our new class, we furnish fixed point theorems for continuous, noncontinuous, monotonic, and nonmonotonic mappings in various kinds of the ordering structures.Article Citation - WoS: 72Citation - Scopus: 75On the Lupas q-analogue of the Bernstein Operator(Rocky Mt Math Consortium, 2006) Ostrovska, SofiyaLet R-n(f,q;x) : C[0, 1] -> C[0, 1] be q-analogues of the Bernstein operators defined by Lupas in 1987. If q = 1, then R-n (f, 1; x) are classical Bernstein polynomials. For q not equal 1, the operators R-n (f, q; x) are rational functions rather than polynomials. The paper deals with convergence properties of the sequence {R-n (f, q; x)}. It is proved that {R-n (f, q(n); x)} converges uniformly to f(x) for any f(x) is an element of C[0, 1] if and only if q(n) -> 1. In the case q > 0, q not equal 1 being fixed the sequence I R. (f, q; x) I converges uniformly to f(x) is an element of C[0, 1] if and only if f(x) is linear.
