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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.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.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.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.Conference Object Citation - Scopus: 8Modeling-Error Based Adaptive Fuzzy Sliding Mode Control for Trajectory-Tracking of Nonlinear Systems(2003) Yu,S.; Yu,X.; Efe,M.O.A novel adaptive fuzzy sliding mode control design is developed for trajectory tracking of a class of nonlinear systems in this paper. This control design uses the modelling error to adaptively estimate the deterministic uncertainties as well as the control gain based on the fuzzy systems approach. By this design, the bounds of the uncertainties are not required to be known in advance, and the robust stability of closed loop systems is analysed in the Lyapunov sense. Simulation results are given to demonstrate the improved performance.Conference Object Statistical Randomness Tests of Long Sequences by Dynamic Partitioning(Ieee, 2020) Akcengiz, Ziya; Asian, Melis; Karabayir, Ozgur; Doganaksoy, Ali; Uguz, Muhiddin; Sulak, FatihRandom numbers have a wide usage in the area of cryptography. In practice, pseudo random number generators are used in place of true random number generators, as regeneration of them may be required. Therefore because of generation methods of pseudo random number sequences, statistical randomness tests have a vital importance. In this paper, a randomness test suite is specified for long binary sequences. In literature, there are many randomness tests and test suites. However, in most of them, to apply randomness test, long sequences are partitioned into a certain fixed length and the collection of short sequences obtained is evaluated instead. In this paper, instead of partitioning a long sequence into lixed length subsequences, a concept of dynamic partitioning is introduced in accordance with the random variable in consideration. Then statistical methods are applied. The suggested suite, containing four statistical tests: Collision Tests, Weight Test, Linear Complexity Test and Index Coincidence Test, all of them work with the idea of dynamic partitioning. Besides the adaptation of this approach to randomness tests, the index coincidence test is another contribution of this work. The distribution function and the application of all tests are given in the paper.Conference Object Citation - Scopus: 16Target Tracking Using Artificial Potentials and Sliding Mode Control(2004) Gazi,V.; Ordóñez,R.In this article we develop an algorithm for capturing/intercepting a moving target based on the sliding mode control method. First, we consider a "kinematic" model (in a sense) for the capture/intercept problem and develop a method for that case. Then, we build on the developed method to include general fully actuated vehicle dynamics for the pursuer agent. The algorithm is robust with respect to the system uncertainties and additive disturbances. Finally, we also provide a numerical simulation in order to illustrate the procedure.Conference Object Citation - WoS: 3Software Architecture in Distributed Software Development: a Review(Springer-verlag Berlin, 2013) Mishra, Alok; Mishra, DeeptiThis paper presents a literature review of distributed software development (DSD) or global software development (GSD) and software architecture. The main focus is to highlight the current researches, observations, as well as practice directions in these areas. The results have been limited to peer-reviewed conference papers and journal articles, and analysis reports that major studies have been performed in software architecture and global software development, while the empirical studies of interfacing distributed/global software development and software architecture has only received very little attention among researchers up to now. This indicates the need for future research in these areas.Conference Object Improvement of Mechanical Performance in Different Concrete Applications Through Use of Steel Fibers(International Committee of the SCMT conferences, 2016) Baran,E.; Mertol,H.C.; Akis,T.The use of steel fibers improves the brittle characteristics of concrete and provides superior mechanical performance compared to the conventional concrete. Remarkable increase in tensile strength and flexural toughness is obtained when steel fibers are used in conventional concrete, mainly due to the crack arrest effect of these fibers. The use of waste materials, such as scrap tires as a source of steel fibers, as well as the resulting increase in service life and the savings in the life cycle cost make the steel fiber reinforced concrete (SFRC) a sustainable construction material. From this perspective, SFRC offers a strong potential for a more sustainable and more economical alternative to conventional concrete. This paper presents examples of how the addition of steel fibers improves the mechanical performance in two different concrete applications: (1) bond behavior of prestressing strands and (2) flexural behavior of reinforced concrete beams. The first part of the study aimed at investigating the variation in bonding mechanism of prestressing strands when used in plain concrete and in SFRC. Pullout tests were conducted on 12.7 mm diameter prestressing strands embedded in SFRC blocks with four different fiber concentrations. This way, the applicability of the available transfer length and development length formulas for prestressing strands embedded in SFRC was investigated. In the second part of the study, flexural behavior of SFRC beams with various levels of flexural reinforcement ratio was studied. The aim was to identify the influence of steel fibers on the mechanical response of lightly and relatively heavily reinforced SFRC beams. The response of SFRC beams and the companion plain concrete beams were evaluated based on the moment capacity, deformation capacity, and service stiffness. © 2016 International Committee of the SCMT conferences. All rights reserved.Conference Object Citation - Scopus: 2Prioritizing Use Cases for Development of Mobile Apps Using Ahp: a Case Study in To-Do List Apps(Springer, 2019) Yildirim,O.; Peker,S.With the rapid development of communication technologies, the uses of mobile apps have increased in a significant manner over the past few years. Every day many different types of mobile apps are uploaded to mobile application markets. However, it is very difficult for the apps to stay competitive and survive in these marketplaces. Covering the requirements fitting the needs of users is one of significant factors in mobile apps’ success in the market. In this regard, this study aims to use Analytic Hierarchy Process (AHP) to evaluate the use cases for the development of mobile apps. The results show that AHP provides an efficient tool which can be used to determine importance of the requirements in mobile apps considering users’ preferences. © 2019, Springer Nature Switzerland AG.
