Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Korunur, Sibel(4)
- Korunur, Murat(3)
- Mahmat, Aybars(3)
- Tosun, Nihat(3)
- Kaya, Turgay(2)
- Onat, Onur(2)
- Serbet, Fatmanur(2)
- Yön, Burak(2)
- Agar, Salih(1)
- Akkurt, Nevzat(1)
- Ali, Ishtiaq(1)
- Ali, Mohabbat(1)
- AǦar, Salih(1)
- Doǧangün, Adem(1)
- Duygu, Kaya(1)
- Emin Öncü, Mehmet(1)
- Fatmanur, Atar(1)
- Fethiye Merve, Kavak Imak(1)
- Gul, Taza(1)
- Gör, Mesut(1)
- Juntharee, Pongpol(1)
- Kangal, Evrim Ersin(1)
- Karaşin, I.B.(1)
- Nasir, Saleem(1)
- Rasul, Sleman Yahya(1)
- Salti, Mehmet(1)
- Saǧlroǧlu, Serkan(1)
- Sirisubtawee, Sekson(1)
- Tosun, Gul(1)
- Turgay, Kaya(1)
- Uslu, Ali(1)
- Uyan, Umut(1)
- Varolgüneş, Sadlk(1)
- Vasiulla, Mohd(1)
- Zengin, Bilgin(1)
- Öncü, Mehmet Emin(1)
- Ünal, İnan(1)
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ3Rényi holographic dark energy-inspired model and scalar field reconstruction in bianchi type III spacetime
Korunur, Murat; Korunur, Sibel
In this study, we consider a cosmological model based on Rényi holographic dark energy within the context of an anisotropic Bianchi type III spacetime geometry. The dark energy density is taken as a modified function of the Hubble parameter, which enables us to express the Einstein field equations in a closed dynamical system. By solving these equations, we obtain the evolution of the Hubble parameter and examine the main cosmological implications of the model. The physical behavior of the universe is discussed through the analysis of the equation-of-state parameter as well as the deceleration parameter. Our results indicate that the universe evolves from an initial decelerated expansion phase toward a late-time accelerated regime. In the asymptotic limit, the model tends to a de Sitter phase, suggesting the presence of a stable attractor configuration. In addition, we reconstruct the dark energy component in terms of different scalar field frameworks, namely quintessence, tachyon, and k-essence models. The associated scalar fields and their potentials are derived and numerically investigated. The obtained results show a coherent late-time behavior, which is in agreement with the observed accelerated expansion of the universe. The small value of the mean anisotropy parameter indicates that this evolution occurs within a quasi-isotropic Bianchi type III background.
- MakaleAçık Erişim2026Scopus SJRQ3Analysis of Visible Light Communication Performance in LOS Propagation Model with PSO-Cosh-Based Filter
Fethiye Merve, Kavak Imak; Fatmanur, Atar; Duygu, Kaya; Turgay, Kaya
Due to the increasing data transfer in wireless communication technologies, Visible Light Communication (VLC), one of the branches of wireless communication technology, is also developing within this framework. VLC holds an advantage over other communication branches in terms of energy efficiency, high bandwidth, and reliability. In this context, research on VLC-based Light Fidelity (Li-Fi) technology has gained momentum in recent years. In systems built with this Li-Fi technology, data is transmitted through an LED bulb, which is used for illumination. In this study, to analyze the performance of systems where data transmission is provided by VLC, the capacity to improve the shape of the transmitted signal is investigated using systems designed with different filtering techniques under LOS channel conditions. The main objective of this study is to demonstrate the improving effect of the proposed PSO-Cosh-based model on the shape of the transmitted signal compared with traditional filtering methods. In this way, in addition to IIR digital filtering techniques, the analysis of the filter coefficients obtained by optimizing the Cosh window function with Particle Swarm Optimization (PSO) demonstrates the originality of the study.
- MakaleYalnız künye2025Scopus SJRQ3Negative Outcome Expectation as a Barrier for Knowledge Sharing: Conceptualisation and Measurement Development
Uyan, Umut
Knowledge sharing has become the critical success factor for effective knowledge management since it bridges the gap between knowledge creation and utilisation. So far, socio-psychological factors have yet to attract the attention of scholars despite numerous barriers impeding the flow of knowledge. The current study is, therefore, designed to develop a self-reporting measurement instrument that uncovers hidden sharing barriers triggered by negative outcome expectations. To test the psychometric properties of the newly designed instrument, a stepwise procedure was applied. The findings indicate that the instrument aimed at developing is a multidimensional construct consisting of 13 items and four dimensions (assumption of being ignored, assumption of not meeting expectations, assumption of being non-sense and assumption of conflict avoidance). The results of this study provide preliminary evidence for the reliability and validity of the 13-item negative outcome expectation scales as a measure of hidden assumptions towards knowledge sharing.
- MakaleYalnız künye2024Scopus SJRQ2Deep learning-assisted Hubble parameter analysis
Salti, Mehmet; Kangal, Evrim Ersin; Zengin, Bilgin
We turn our attention on evaluating the most recent Hubble parameter data measured via the differential evolution of cosmic-chronometers from a deep learning perspective. To achieve this goal, we start our investigation by introducing the selected theoretical setup and compiling the most recent statistical data obtained in cosmology experiments. Then we implement a tuned version of the long-short term memory (LSTM) architecture and run it to predict possible values of the Cosmic Hubble parameter for different red-shift states. Since we observe a good correlation between the observed and predicted datasets of the Hubble parameter, we conclude that the machine learning approaches can play important roles in the future cosmology investigations.
AtıfScopus2WoS2OpenAlex2
İncele - MakaleYalnız künye2024Scopus SJRQ3Simultaneous features of ternary hybrid nanoparticles on thermal radiative flow configured by Darcy–Forchheimer porous surface
Nasir, Saleem; Sirisubtawee, Sekson; Akkurt, Nevzat; Ali, Ishtiaq; Gul, Taza; Juntharee, Pongpol
Due to its remarkable thermodynamic development in various engineering sciences, the dispersion of nanostructures in classical base liquids is receiving greater attention from researchers and scientists. In light of the aforementioned inspirations, the suggested research is associated with using a water-based ternary-hybrid nanofluid that contains three unique nanostructures, silicon dioxide, titanium dioxide and aluminum oxide to optimize the heating process in science and engineering. In this situation, the influence of a chemically reactive magneto-hydrodynamics (MHD) Darcy–Forchheimer ternary hybrid composites transport involving nonlinear radiation across an exponentially permeable stretched surface is highlighted with the model's physical initial and boundary constraints. The simulation of the heat expression also includes the impacts of nonlinear thermal radiations, energy supply, energy dissipation and magnetic force. Furthermore, the interpretation of Buongiorno's theory involves spontaneous and thermophoresis diffusions. Entropy analysis is explained using the second law of thermodynamics. We converted the model framework for fluid movement, energy and mass transfer (together with ternary hybrid nanofluid characteristics) into self-similar nondimensional differential equations, that were then further analytically evaluated by using the homotopy asymptotic method (HAM) technique via Mathematica software. The acquired results are illustrated numerically and graphically to study the behavior of fluid flow, heat, concentration distribution, drag force, rate of heat and mass transfer for various emergent components to gain scientific comprehension. With the growing values of magnetic, porosity and Forchheimer number, the nature of the velocity profile goes down.
AtıfScopus10OpenAlex11İncele - MakaleAçık Erişim2024Scopus SJRQ2Seismic Resistance and Performance Evaluation of Masonry Dwellings After the February 6, 2023, Kahramanmaraş Earthquake Sequence in Türkiye
Onat, Onur; Yön, Burak; Uslu, Ali; Öncü, Mehmet Emin; Varolgüneş, Sadlk; Karaşin, I.B.; Gör, Mesut
On February 6, 2023, two catastrophic earthquakes occurred on the East Anatolian Fault. The earthquakes had magnitudes of Mw = 7.7 and 7.6 and struck Kahramanmaraş-Pazarclk and Kahramanmaraş-Elbistan, respectively. The Kahramanmaraş-Pazarclk earthquake was triggered at 04:17 local time on the Dead Sea Fault (a branch of the East Anatolian Fault). The last earthquake on the addressed fault occurred about 500 years ago. The recorded peak ground acceleration (PGA) at the Pazarclk station reached 2.05g. In addition, the Pazarclk earthquake triggered two independent earthquakes, the Nurdaǧl and Islahiye earthquakes, which occurred 10 min later than the Pazarclk earthquake. However, the last earthquake, with its epicenter in Kahramanmaraş-Elbistan, struck at 13:24 local time. The recorded PGA for the Elbistan earthquake is 0.68g. This study aims to present the fault rupture mechanism of the February 6, 2023, Kahramanmaraş earthquakes, earthquake characteristics, and to evaluate the performance of masonry dwellings during the Kahramanmaraş earthquake doublet, which affected 10 provinces and numerous towns and villages. This paper also aims to illustrate the damage and failure mechanisms of the masonry dwellings, despite unexpectedly high accelerations that exceeded the design spectrum in the field, specifically in Kahramanmaraş, Gaziantep, Hatay, and Malatya, according to the current earthquake code in use.
AtıfScopus16OpenAlex22İncele - MakaleAçık Erişim2024Scopus SJRQ3Effects of vibration conditions on machinability of aisi 52100 bearing steel
Agar, Salih; Tosun, Nihat; Mahmat, Aybars
This study focused on determining the effects of the cooling condition in the conventional and ultrasonic-assisted turning of AISI 52100 steel. AISI 52100 steel has been widely used in the bearing, mold, and automotive industries because of its superior wear resistance and mechanical properties. However, its high wear resistance caused poor machinability in conventional machining methods. Low surface quality, rapid tool wear, high cutting temperature, and high cutting force are the main difficulties in the conventional machining of AISI 52100 steel. On the other hand, ultrasonic-assisted machining has become widely used in the past decades for the machining of materials that have low machinability in conventional methods. Conventional turning and ultrasonic-assisted turning were selected as machining methods. Ultrasonic-assisted turning experiments were conducted under 20 and 30 kHz vibration frequencies. Cubic Boron Nitride (CBN) cutting tools were used in machining experiments. In machining operations 50, 100, and 150 m/min cutting speeds were selected, and feed rate (0.1 mm/rev) and depth of cut (0.5 mm) were kept constant in experiments. Minimum quantity lubrication technique which used 1% Al2O3 nanoparticle additives cutting fluid and dry cooling methods were used. CBN insert was used as a cutting tool. The effects of cutting speed, cutting method, and cooling condition on surface quality, cutting force, cutting zone temperature, and cutting tool wear were studied experimentally. Analysis of Variance (ANOVA) was carried out to determine the significance of the effects of input variables on process outputs. As a result of this study, it is determined that combined UAT and nanoMQL have significant effects on the process outputs.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2024Scopus SJRQ2Energy-Momentum distributions of cylindrical black hole in rainbow gravity
Korunur, Murat; Korunur, Sibel
In this study, the energy-momentum localization problem is addressed within the framework of rainbow gravity. Considering the black string black hole, one of the cylindrical black hole models, energy-momentum distributions are obtained for Einstein, Bergmann-Thomson, and Landau-Liftshitz prescriptions in rainbow gravity. All prescriptions' energy densities are non-zero and depend on the rainbow functions, while the momentum distributions are zero. It has been observed that space-time energy does not depend on the energy of the test particle for some particular choices of rainbow functions. The results obtained for all special cases are given in a table.
AtıfScopus4WoS4OpenAlex4İncele - MakaleYalnız künye2024Scopus SJRQ2A study of mixed super quasi-Einstein manifolds with applications to general relativity
Vasiulla, Mohd; Ali, Mohabbat; Ünal, İnan
In this paper, we explore a set of geometric properties of Mixed Super Quasi-Einstein (MSQE) manifolds and provide examples of both Riemannian and Lorentzian MSQE manifolds to demonstrate their existence. Furthermore, we examine MSQE spacetimes in the context of the space-matter tensor, discussing several related properties. Finally, we establish the existence of an MSQE spacetime through a nontrivial example.
AtıfScopus3WoS4OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ3ENHANCING MILLING PERFORMANCE OF 6061 ALUMINUM ALLOY WITH NANOCUTTING FLUID AND MQL
Tosun, Nihat; Rasul, Sleman Yahya; Mahmat, Aybars; Tosun, Gul
During the machining of aluminum alloys, the adhesion of chips to the tool affects the performance characteristics. Today, different cooling systems are used to eliminate these negativities. In this study, the effects of end milling using HSS and carbide cutting tools of 6061-T6 aluminum alloy on surface roughness, chip thickness ratio and tool wear were examined using different cooling techniques (dry, minimum quantity lubrication (MQL) and nanocutting fluid). Different cutting speeds (180, 200, 220 m/min) and different feed rates (0.05, 0.06, 0.07 mm/rev) were used in the experiments. According to experimental findings, tool wear and surface roughness decreased at low cutting speed and feed rate by using nanocutting fluid with carbide cutting tools. It has been observed that the chip thickness ratio increases with high cutting speeds using nanocutting fluid and decreases with dry machining and high feed rates. The best milling performance of the aluminum alloy was achieved in experiments using carbide cutting tools and nanocutting fluid.
AtıfScopus4WoS4OpenAlex4İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ3Optimization Approach in Window Function Design for Real-Time Filter Applications
Serbet, Fatmanur; Kaya, Turgay
Eliminating the Gibbs oscillations that occur during the Finite Impulse Response (FIR) digital filter design with the Fourier Series method will ensure correct filtering. For this reason, the development of the window improves the performance of the filter and, therefore, the system. In this study, the cosh window function is designed using Particle Swarm Optimization, which is a preferred optimization method in many areas. Thus, alternatives to the standard results obtained from the existing traditional calculations will be produced, and different windows that perform the same function will be obtained. In addition, exponential and cosh window functions were designed in LabVIEW environment, which is a graphical programming language-based program, and the designed windows were analyzed at different parameter values. LabVIEW provides a fast and easy programming environment, and it provides the opportunity to realize real-Time applications with its external hardware. Utilizing this feature, the amplitude spectrum of cosh window designed in LabVIEW is displayed in real time for different window parameter values. As a result, FIR digital filters were designed using cosh window based on optimization and the cosh window designed in LabVIEW, and the distorted EEG signal was filtered using these filters and displayed in real time.
AtıfScopus8WoS5OpenAlex5İncele - MakaleAçık Erişim2023Scopus SJRQ3Statistical Analysis and EEG Signal Filtering Using Design of Window Function Based on Optimization Methods
Serbet, Fatmanur; Kaya, Turgay
The window functions, which are widely used in Finite Impulse Response (FIR) digital filter design with the Fourier Series Methods, aim to eliminate the oscillations adversely affecting the filter performance that occur during the filter design. Window functions, which were developed with different methods in the literature, were designed with three different optimization techniques in this study. By using Particle Swarm Optimization (PSO), Grey Wolf Colony Optimization (GWCO), Cuckoo Search Optimization (CSO) algorithms, which are among current metaheuristic optimization methods, new window functions are designed for FIR digital filter design such that the designed new window functions have different window coefficients and design parameters. The difference of the designed window functions was analyzed with the Friedman and Wilcoxon tests, which are statistical data analysis methods, and the originality of the designed window functions was proven. FIR digital filters that can perform the same operation as the designed window functions have been produced and the results obtained by performing the filtering application of the EEG signal with the produced filters are presented in the study.
AtıfScopus9WoS6OpenAlex7İncele - MakaleAçık Erişim2023Scopus SJRQ3EFFECT of the COOLING with AIR and WATER VAPOR on MILLING PERFORMANCES
Mahmat, Aybars; Tosun, Nihat; AǦar, Salih
This study aims to investigate experimentally and analytically the effects of different machining parameters such as cooling methods and cutting tool materials on surface roughness and chip thickness ratio for milling of AA7075-T6 aluminum alloy. The carbide and high-speed steel (HSS) end mills were used as cutting tools and the conventional, vapor, and compressed air were used as cooling methods in the experiments. The experiment conditions for compressed air at the cutting zone were 6 bar pressure and 30 m/s speed flow rate. A mixture of boron oil and water (1/20 mixture ratio) was used as cutting fluid in conventional cooling. The study was carried out using three levels of feed rates (20, 40, 80 mm/min), rotational speeds (780, 1330, 2440 rpm), and a constant 2 mm deep cut. As a result of the experiments, the surface roughness values increased with the increasing levels of feed rate. Besides surface roughness values decreased with increasing levels of the rotational speed. In addition, a better surface quality was obtained in milling processes by using carbide cutting tools compared to HSS tools. It was concluded that the most important parameter affecting the surface roughness and chip thickness ratio is feed rate and the rotational speed, respectively. Better surface roughness and chip thickness ratio were obtained from the vapor processing than the conventional and compressed air.
AtıfScopus2WoS1İncele - MakaleYalnız künye2023Scopus SJRQ2Energy-momentum localization in rainbow gravity
Korunur, Murat; Korunur, Sibel
Theoretical physicists generally prefer to modify the general theory of relativity rather than avoiding the successful approaches that have been offered to us. Hence, the rainbow formalism of gravity, which is one of the most studied quantum gravity candidates in literature, has recently gained importance in the field. In this study, the energy-momentum localization problem is discussed for the Taub universe within the framework of rainbow gravity. To achieve this goal, energy and momentum components are calculated by making use of diverse values of rainbow functions in the Einstein, Bergmann-Thomson, Landau-Lifshitz, and the Papapetrou prescriptions for the geometry under consideration. Except for the Landau-Lifshitz prescription, all prescriptions depend on the rainbow functions and the momentum components vanish. Graphical analysis is performed for all the energies obtained. Also, it is shown in limiting condition f1(x) → 1; f2(x) → 1 that the results are compatible with the ones obtained in the general relativity.
AtıfOpenAlex1İncele - MakaleYalnız künye2022Scopus SJRQ2Kaniadakis holographic dark energy with scalar field in Bianchi type-V universe
Korunur, Sibel
In this work, considering anisotropic and homogeneous Bianchi type-V universe we investigated Kaniadakis holographic dark energy (KHDE). It is demonstrated that the equation of state (EoS) parameter has a transition from the quintessence era to the phantom era for the chosen model. Additionally, in the late time of the universe, EoS parameter behaves like a cosmological constant (Λ) with an IR (Infrared) cut-off apparent horizon in case of a particular form of deceleration parameter. We reconstructed correspondence between the KHDE and tachyon, quintessence and k-essence scalar fields. Also, our numerical solutions have been shown in graphs for EoS parameter and scalar fields.
AtıfScopus7WoS8OpenAlex9İncele - MakaleYalnız künye2021Scopus SJRQ3Seismicity of East Anatolian of Turkey and Failures of Infill Walls Induced by Major Earthquakes
Doǧangün, Adem; Yön, Burak; Onat, Onur; Emin Öncü, Mehmet; Saǧlroǧlu, Serkan
There are three major fault zones in Turkey scattered around the country known as East Anatolian Fault (EAF), North Anatolian Fault (NAF) and Anatolian-Aegean Subduction Zone (AASZ). Last two decades, EAF has been rather quiescent compared with NAF. However, this quiescence was broken in the beginning of the millennium. The strong shaking was started in 2003 with Bingöl earthquake (Mw = 6.3) and the last earthquake on the EAF is the Sivrice-Elazlǧ (Mw = 6.8) on January 24, 2020. Strong seismicity of these faults damaged the structures severely and caused death of the habitants. This study aims to present, seismotectonic of the region, general characteristics of the earthquakes and more specifically to report structural damage of infill walls of the structure's damages caused by these earthquakes. Damage evaluation and identification of the observed infill wall damages due to 2003 Bingöl, 2011 Van earthquakes and January 24, 2020 Sivrice-Elazlǧ earthquake occurred Turkey's Eastern region, were presented, and possible solutions were suggested. Moreover, the effects of the infill walls on the behavior of structures under static and dynamic load cases are discussed that experienced in these earthquakes. Damages are classified according to formations such as in-plane or out-of-plane, evaluations and the results obtained from the discussions are presented for each category.
AtıfScopus35WoS32İncele - DergiInternational Journal of Modern Physics A
- DergiInternational Journal of Modern Physics B
- DergiJournal of Earthquake and Tsunami
- DergiSurface Review and Letters