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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 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: 5Citation - Scopus: 5Development and Psychometric Analysis of a Pediatric Oncology Nurses' Educational Needs Scale(Wiley, 2023) Kudubes, Asli Akdeniz; Semerci, Remziye; Ozbay, Sevil Cinar; Ay, Ayse; Boztepe, HandanBackground/objectivesIt is important to determine the educational needs of pediatric oncology nurses in order to maximize and implement nursing care interventions. Therefore, this study aims to develop a valid and reliable measurement tool to determine pediatric oncology nurses' educational needs and examine its psychometric properties. Design/methodsThis methodological study was conducted with 215 pediatric oncology nurses in Turkey between December 2021 and July 2022. Data were collected with the "Nurse Information Form" and "Pediatric Oncology Nurses' Educational Needs Scale." IBM SPSS 21.0 and IBM AMOS 25.0 software programs were used for data analysis, and descriptive statistics were used to analyze numeric variables. Exploration and confirmatory factor analyses were performed to determine the scale's factorial structure. ResultsThe factorial analysis was used to test the structural validity of the scale. A five-factor structure consisting of 42 items was developed. The Cronbach's alpha coefficient for "Illness" was .978, "Chemotherapy and Side Effect" was .978, "Another Therapy and Side Effect" was .974, "Palliative Care" was .967, "Supportive Care" was .985, and the total score was .990. Fit indices resulting from the study were chi(2)/SD: 3.961, root mean square error of approximation (RMSEA): 0.072, goodness-of-fit index (GFI): 0.95, comparative-of-fit index (CFI): 0.96, and normed fit index (NFI): 0.95. ConclusionThe Pediatric Oncology Nurses' Educational Needs Scale is a valid and reliable scale for pediatric oncology nurses to determine their educational needs.Conference Object Citation - WoS: 2Object-Oriented Inheritance Metrics: Cognitive Complexity Perspective(Springer-verlag Berlin, 2009) Mishra, Deepti; Mishra, AlokIdentifying high cognitive complexity modules can lead to a better quality software system and can help during maintenance also. It has been found that inheritance has an impact on cognitive complexity of a software system. In this paper, two inheritance metrics based on cognitive complexity, one at class level CCI (Class Complexity due to Inheritance) and another at program level ACI (Average Complexity of a program due to Inheritance), have been proposed for object-oriented software systems. These metrics are also compared with other well known object-oriented inheritance metrics.Book Part A Simulation Environment for Cybersecurity Attack Analysis Based on Network Traffic Logs(inst Engineering Tech-iet, 2019) Daneshgadeh, Salva; Oney, Mehmet Ugur; Kemmerich, Thomas; Baykal, NazifeThe continued and rapid progress of network technology has revolutionized all modern critical infrastructures and business models. Technologies today are firmly relying on network and communication facilities which in turn make them dependent on network security. Network-security investments do not always guarantee the security of organizations. However, the evaluation of security solutions requires designing, testing and developing sophisticated security tools which are often very expensive. Simulation and virtualization techniques empower researchers to adapt all experimental scenarios of network security in a more cost and time-effective manner before deciding about the final security solution. This study presents a detailed guideline to model and develop a simultaneous virtualized and simulated environment for computer networks to practice different network attack scenarios. The preliminary object of this study is to create a test bed for network anomaly detection research. The required dataset for anomaly or attack detection studies can be prepared based on the proposed environment in this study. We used open source GNS3 emulation tool, Docker containers, pfSense firewall, NTOPNG network traffic-monitoring tool, BoNeSi DDoS botnet simulator, Ostinato network workload generation tool and MYSQL database to collect simulated network traffic data. This simulation environment can also be utilized in a variety of cybersecurity studies such as vulnerability analysis, attack detection, penetration testing and monitoring by minor changes.
