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Review Citation - WoS: 73Citation - Scopus: 112Devops and Software Quality: a Systematic Mapping(Elsevier, 2020) Mishra, Alok; Otaiwi, ZiadoonQuality pressure is one of the factors affecting processes for software development in its various stages. DevOps is one of the proposed solutions to such pressure. The primary focus of DevOps is to increase the deployment speed, frequency and quality. DevOps is a mixture of different developments and operations to its multitudinous ramifications in software development industries, DevOps have attracted the interest of many researchers. There are considerable literature surveys on this critical innovation in software development, yet, little attention has been given to DevOps impact on software quality. This research is aimed at analyzing the implications of DevOps features on software quality. DevOps can also be referred to a change in organization cultures aimed at removal of gaps between the development and operations of an organization. The adoption of DevOps in an organization provides many benefits including quality but also brings challenges to an organization. This study presents systematic mapping of the impact of DevOps on software quality. The results of this study provide a better understanding of DevOps on software quality for both professionals and researchers working in this area. The study shows research was mainly focused in automation, culture, continuous delivery, fast feedback of DevOps. There is need of further research in many areas of DevOps (for instance: measurement, development of metrics of different stages to assess its performance, culture, practices toward ensuring quality assurance, and quality factors such as usability, efficiency, software maintainability and portability). (C) 2020 The Author(s). Published by Elsevier Inc.Article Citation - WoS: 5Citation - Scopus: 5Improvement of Electrical Characteristics of Snse/Si Heterostructure by Integration of Si Nanowires(Elsevier, 2021) Coskun, E.; Gullu, H. H.; Emir, C.; Parlak, M.In this study, the effects of the nanowire geometry on Si wafer substrate were investigated for the SnSe/Si-nanowire heterojunction device and the obtained results were compared with the one fabricated on planar Si surface. Nanowires on Si surface were produced by metal-assisted etching method and the SnSe film layer was deposited by thermal evaporation technique. On both Si and glass surfaces, deposited film shows polycrystalline and single SnSe phase. From optical transmission measurements, optical band gap of this film was determined as 1.36 eV in a good agreement with the literature. All SnSe/Si heterostructures were found in a p-n diode behavior and the ideality factor and series resistance values were calculated as 2.40, 547 Omega, and 3.71, 1.57 x 10(3) Omega, for SnSe/Si-nanowire and SnSe/Si heterojunctions, respectively. As a result, an improvement in device characteristics concerning the planar Si structure was found by utilizing Si nanowire structure.Article Citation - WoS: 7Citation - Scopus: 6Spectroscopic Ellipsometry Characterization of Pbwo4 Single Crystals(Elsevier, 2022) Delice, S.; Isik, M.; Gasanly, N. M.; Darvishov, N. H.; Bagiev, V. E.Optical characterization of PbWO4 single crystals grown by Czochralski method was achieved in virtue of spectroscopic ellipsometry experiments carried out in the energy region of 1.0-5.6 eV at room temperature. Tetragonal scheelite structure with lattice parameters of a = b = 5.4619 & Aring; and c = 12.0490 & Aring; was determined for the bulk crystal utilizing from XRD analysis. Analyses of the ellipsometry data presented the photon energy dependencies of complex dielectric function of the crystal. The real part of the dielectric function exhibited increasing behavior with energy in the below 4.1 eV and then decreased immediately. Zero frequency refractive index and dielectric constant were determined to be 2.02 and 4.08, respectively, using Wemple and DiDomenico oscillator model. High frequency dielectric constant was calculated as 4.30 by Spitzer-Fan model. Optical band gap of PbWO4 was found to be 3.24 eV from the dielectric relaxation time spectrum. Moreover, existence of two critical points with energies of 3.70 and 4.58 eV was revealed from the analyses of extinction coefficient and second derivative of the dielectric function. These levels were considered to be due to creation of cation exciton (Pb2+ 6s(2) - Pb2+ 6s6p) and transitions in the [WO4](2-) group.Article Citation - WoS: 25Citation - Scopus: 33Dynamic Behavior of k-out-of-n< Systems(Elsevier, 2011) Eryilmaz, Serkan; Erylmaz, SerkanIn this paper, we study the distribution and expected value of the number of working components at time t in usual and weighted k-out-of-n:G systems under the condition that they are working at time t. We evaluate the distribution of the corresponding conditional random variable and compute its expected value for the systems consisting of independent but nonidentical components. Illustrative examples are presented and an optimization problem which makes use of the conditional random variable is also formulated and solved numerically. (c) 2011 Elsevier B.V. All rights reserved.Article Citation - WoS: 17Citation - Scopus: 17Effects of Fluorination and Thermal Shock on the Photocatalytic Activity of Bi2o3< Nanopowders(Elsevier, 2021) Bouziani, Asmae; Park, Jongee; Ozturk, AbdullahFluorinated Bi2O3 (F-Bi2O3) nanopowder was prepared via fluorination followed by thermal shock of alpha-Bi2O3 nanopowder. The XRD, FTIR, SEM, and DRS characterization techniques were employed to investigate the effects of fluorine (F) insertion into the alpha-Bi2O3 host and the thermal shock from different temperatures. The crystal structure, optical and photocatalytic properties of the F-Bi2O3 nanopowders prepared were researched. The XRD results confirmed the substitution of O2- with F-. The FTIR results revealed that the coordination of Bi atoms changed upon F- substitution. The incorporation of F into the alpha-Bi2O3 host and thermal shock did not influence the morphology but modified the band structure of alpha-Bi2O3, leading to a red-shift in the optical absorption edge. Also, the bandgap narrowed from 2.8 eV to 2.6 eV. The density functional theory calculation proved that the F 2p orbitals were positioned in the valence band (VB), resulting in broader and more spread bands for F-Bi2O3. The results suggested that the photoexcited charge carrier mobility in the valence band (VB) and conduction band (CB) are enhanced upon F insertion into alpha-Bi2O3. The photocatalytic efficiency of the synthesized nanopowders was assessed by the degradation of Bromocresol Green (BG) under visible light illumination. Photocatalytic activity improved upon fluorination. The F-Bi2O3 nanopowders thermally shocked from higher temperatures showed negligible photocatalytic performance. The best photocatalytic performance of 70% BG degradation was realized after 180 min visible irradiation for the F-Bi2O3 nanopowder thermal shocked from 500 degrees C.Article Citation - WoS: 6Citation - Scopus: 7Approximation of Oscillatory Bessel Integral Transforms(Elsevier, 2023) Khan, Suliman; Zaman, Sakhi; Arshad, Muhammad; Alhazmi, Sharifah E.; Khan, Feroz; Park, JongeeThe numerical treatment of oscillatory integrals is a demanding problem in applied sciences, particularly for large-scale problems. The main concern of this work is on the approximation of oscillatory integrals having Bessel-type kernels with high frequency and large interpolation points. For this purpose, a modified meshless method with compactly supported radial basis functions is implemented in the Levin formulation. The method associates a sparse system matrix even for high frequency values and large data points, and approximates the integrals accurately. The method is efficient and stable than its counterpart methods. Error bounds are derived theoretically and verified with several numerical experiments.(c) 2023 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 5Automata Networks as Preprocessing Technique of Artificial Neural Network in Estimating Primary Production and Dominating Phytoplankton Levels in a Reservoir(Elsevier, 2006) Kilic, Hurevren; Soyupak, Selcuk; Gurbuz, Hasan; Kivrak, ErsinArtificial Neural Networks (ANN) is computational architectures that can be used for estimating primary production levels and dominating phytoplankton species in reservoirs. Automata Networks (AN) were applied as a pre-processing method with subsequent ANN model development for Demirdoven Dam Reservoir. The primary purpose of using preprocessing technique was to distinguish the suitable and appropriate constituents of the input parameters' matrix, to eliminate redundancy, to enhance prediction power and calculation efficiency. The data were collected monthly over two years. The applications have yielded following results: The correlation coefficients (r values) between predicted and observed counts were as high as 0.83, 0.87, 0.83 and 0.88 for Cyclotella ocellata, Sphaerocystis schroeteri, Staurastrum longiradiatum counts, and Chlorophyll-a (Chl-a) concentrations respectively with AN. The performance of AN based pre-processing technique was compared with the performance of a well-known pre-processing technique, namely Principle Component Analysis(PCA), experimentally. r values between the predicted and observed C. ocellata, S. schroeteri and S. longiradiatum counts, and (Chl-a) were as high as 0.80, 0.86, 0.81 and 0.86 respectively with PCA. (c) 2006 Elsevier B.V. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 1Simulating Hawking Radiation in Quantum Many-Body Systems: Deviations From the Thermal Spectrum(Elsevier, 2025) Alkac, Gokhan; Ozgun, EgeWe investigate a recently proposed one-to-one correspondence between quantum field theories in twodimensional curved spacetime and quantum many-body systems, which enables the simulation of Hawking radiation in static background spacetimes. In particular, we demonstrate that deviations from the thermal spectrum, as predicted by the well-known tunneling method, can be observed in many-body simulations.Article Citation - WoS: 8Citation - Scopus: 9Usability Study of a Smart Toy on Students With Intellectual Disabilities(Elsevier, 2018) Ekin, Cansu Cigdem; Cagiltay, Kursat; Karasu, NecdetThis paper introduces a smart toy (SmartAnimals) which provides a mixed reality environment for children with intellectual disabilities. SmartAnimals includes a virtual space including computer based animations, sounds and characters, and a real space including plastic toys, and a receiver panel. SmartAnimals with a flexible context leads children to learn daily life concepts easily. To test usability of SmartAnimals, an empirical study was carried out with 6 children having intellectual disability (ID) and four special education teachers. The findings indicated that smart toys could be beneficial for children with ID especially who have limited concentration. It enables children with easy and fast learning. Smart toys also affect children's performance in a positive way while learning cognitive concepts.Book Part Citation - Scopus: 12Water Flux and Reverse Salt Flux(Elsevier, 2018) Koseoglu,H.; Guler,E.; Harman,B.I.; Gonulsuz,E.Following the increase in the world population and the demand for economic development, the need for energy has increased day by day. Rapidly increasing global energy consumption is supplied mainly by fossil fuels bearing the risk of exhaustion with decreasing reserves, which now have the effect of carbon emissions and greenhouse gases. These concerns lead humanity to significantly reduce the use of fossil fuels. Salinity gradient energy (SGP), a type of hydroelectric energy, also has a high potential to displace fossil fuels. SGP is less periodic than sources like wind and solar energy. The osmotic pressure gradient energy uses the released energy during mixing of the water currents with different salinity The Gibbs free energy from mixing two solutions of different concentrations is an unnoticed source of energy. Salinity gradient energy, also referred to as osmotic energy or blue energy, can be derived from natural sources such as clean river water, salt water, and desalination of seawater. Various approaches have been developed to capture salinity gradient energy, but the most promising are pressure-retarded osmosis (PRO), reverse electrodialysis (RED) and forward osmosis (FO) processes. In this chapter theoretical approaches derived from the current literature is presented for the deep conceptual understanding of the water flux and reverse salt flux issues. © 2018 Elsevier B.V. All rights reserved.
