Yayınlar
Koleksiyondaki öğeler
- MakaleAçık Erişim2025Scopus SJRQ2Enhancing part-based gait recognition via ensemble learning and feature fusion
Yaprak, Büşranur; Gedikli, Eyüp
Gait, a behavior-based biometric feature, has gained increasing popularity in human identification, particularly in surveillance systems, due to its ability to function without physical contact or explicit consent. Traditional silhouette-based methods have demonstrated that different body parts exhibit distinct movement patterns during walking, thereby enhancing recognition accuracy. In this study, we propose an improved part-based gait recognition approach by leveraging ensemble learning on local body regions. The Gait Energy Image (GEI) is segmented into five horizontal parts, and ensemble learning is applied to the convolutional neural network (CNN) responsible for their processing. A separate MetaModel is trained for each body part to integrate the part-based features obtained from ensemble learning and synthesize the most discriminative ones. Additionally, a part-removal process is introduced to mitigate the effects of appearance-based variations by analyzing absolute differences between images with and without variations. The aggregated most distinctive features contribute to robust recognition. We evaluate our proposed approach on the CASIA-B, CASIA-C, and Outdoor-Gait datasets, and experimental results indicate that ensemble learning significantly enhances part-based gait recognition performance under various appearance variations, outperforming several state-of-the-art methods. The datasets and source code are available at https://github.com/busrakckugurlu/Enhancing-Part-based-Gait-Recognition-via-Ensemble-Learning-and-Feature-Fusion/tree/main.
AtıfScopus9WoS3OpenAlex7
İncele - MakaleYalnız künye2009Scopus SJRQ1Implementation of different encoding types on structural optimization based on adaptive genetic algorithm
Bekiroǧlu, Serkan; Dede, Tayfun; Ayvaz, Yusuf
In this study, the use of new alternatives of encoding types such as quaternary encoding and octal encoding is reviewed along with that of binary and value encodings and how they provide contribution to efficiency and robustness of genetic algorithm is discussed in structural problems. In addition to new alternatives of encoding types, a genetic algorithm with adaptive manner is presented so that an adaptive approach including adaptive mutation and adaptive crossover operators is employed. It is concluded that it is not possible to tell that one of the encoding types is exactly dominant over the others in all aspects such as convergence, finding the optimum solution, and iteration number. However, it is worth to say that to run genetic process with different encoding types should be considered since one of the runs can give more appropriate solution than that of the others.
AtıfScopus24WoS21OpenAlex26İncele - MakaleAçık Erişim2025Scopus SJRQ4THE MODERATING ROLE OF PRICE SENSITIVITY AND THE MEDIATING ROLE OF SWITCHING COSTS IN THE MOBILE OPERATOR SWITCHING BEHAVIOR OF UNIVERSITY STUDENTS IN TURKEY; [MODERATORSKA ULOGA CJENOVNE OSJETLJIVOSTI I MEDIJACIJSKA ULOGA TROŠKOVA PROMJENE U PONAŠANJU PROMJENE MOBILNOG OPERATORA KOD STUDENATA SVEUČILIŠTA U TURSKOJ]
Avci, Ibrahim
Purpose – The aim of this research study is to assess the effects of service quality and satisfaction on intentions of university students to switch operators, as well as the moderating function of price sensitivity in these effects. Furthermore, the influence of switching costs as a mediator between operator switching intention and operator switching behavior is investigated. Design/methodology/approach – A quantitative research involving students from a Turkish university was conducted. The research hypotheses were tested using structural equation modeling (partial least squares regression) using data from 425 students. Findings and implications – The analysis revealed that service quality had a positive influence and satisfaction had a negative effect on operator switching intention, with price sensitivity acting as a moderator in the relationship between satisfaction and switching intention. It was also determined that operator switching cost plays a partial mediator role in the link between operator switching intention and behavior. Research findings will help organizations understand the elements that affect switching intentions and behavior. It is proposed that operator businesses pay attention to customer satisfaction and implement retention and acquisition tactics. Limitations – The research was limited to operator switching. Furthermore, the findings are specific to the survey participants and cannot be generalized. Originality/value – The fact that the moderating role of price sensitivity and the mediating role of switching cost are investigated in this research highlights its significance, while the findings in this context make significant contributions to the field by filling a gap in the literature.
- MakaleAçık Erişim2025Scopus SJRQ2Comprehensive Analysis of the Antioxidant and Enzyme Inhibitory Properties and Phenolic Compounds of Phlomis armeniaca: Potential Applicant in Neurodegenerative Diseases
Menevseoglu, Ahmed; Yılmaz, Fırat; Topal, Meryem; Topal, Fevzi
This study investigates the antioxidant and enzyme inhibitory properties of Phlomis armeniaca, a perennial plant native to the eastern and southeastern regions of Turkey. Ethanol extracts of the plant were analyzed using various bioanalytical methods, including Fe3⁺-Fe2⁺ reducing power, Cupric Reducing Antioxidant Capacity, 1,1-diphenyl-2-picryl-hydrazyl (DPPH), and 2,2-azinobis 3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging activities, as well as total phenolic and flavonoid content assessments. The results showed that P. armeniaca is rich in phenolic (38.75 ± 0.59 µg gallic acid equivalents/mg extract) and flavonoid compounds (39.34 ± 4.08 µg quercetin equivalents/mg extract). The plant demonstrated significant inhibitory effects on acetylcholinesterase (half-maximal inhibitory concentration [IC50]: 45.00 ± 0.48 mg/mL) and butyrylcholinesterase (IC50: 84.51 ± 0.84 mg/mL) enzymes, indicating its potential use in treating neurodegenerative diseases such as Alzheimer's. The study also highlighted P. armeniaca’s high chlorogenic acid, salicylic acid, 4-dihydroxybenzoic acid, and quinic acid contents, supporting its antioxidant capacity. These findings suggest that P. armeniaca could be a valuable natural resource for developing therapeutic agents to manage oxidative stress and related conditions, warranting further pharmacological exploration.
AtıfScopus5WoS5OpenAlex5
İncele - MakaleAçık Erişim2024Scopus SJRQ1Central composite design modelling and developing a method for removing sulphate from an alunitic kaolin ore
Erkan, İlker; Inal, Serkan; Alp, İbrahim
The main mineral in kaolin ore, kaolinite, is well-known for its many uses in the paint, paper, and ceramics industries. The necessity of getting pure kaolinite is discussed in this work, with an emphasis on the extraction of impurities from kaolin. Specifically, alunitic kaolin, which is common in northwest Turkey, has sulfur concentrations higher than 3 % SO3, which means that it can't be used for many industrial purposes. Leaching is a popular method for removing sulfur, especially when done directly and through pre-treatment techniques like roasting. High-temperature roasting, however, presents difficulties since it causes phase transformation on kaolinite to metakaolin and mullite and on alunite to alum. The temperature of phase transformation is important on high temperature studies which affects negatively the thixotropic qualities that are essential for the production of ceramics. This study introduces a novel approach by optimizing roasting conditions and employing a central composite design methodology for leaching. The optimal parameters for the roasting studies were determined to be 525 °C for 3 h. For leaching, the ideal conditions were identified using the leaching recovery equation, which specifies 0.195 M NaOH, 80 °C, 127 min, and a 2.55 % solid content. These characteristics were confirmed by follow-up experiments, which showed a change in SO42− concentration from 3.03 % to 2.97 %, along with some structural changes in the roasted sample. The subsequent leaching process resulted in a significant drop in SO42− concentration to 0.46 %. By highlighting the effectiveness of lower-temperature roasting and optimizing experimental methodology, this research presents a novel thermochemical method for sulfur removal in alunitic kaolin.
AtıfScopus1WoS1OpenAlex2İncele - MakaleYalnız künye2024Consumer Protection in the Digital Era: An Analysis of Consumer Protection in E-Commerce
Septiningsih, Ismawati; Karimullah, Suud Sarim
The digital revolution has fundamentally reshaped the way consumers interact with the marketplace. The emergence of e-commerce platforms has accelerated economic transactions while simultaneously introducing complex legal challenges, particularly regarding consumer protection. This study critically examines the effectiveness of consumer protection mechanisms in the digital era, with a focus on e-commerce practices in both domestic and cross-border contexts. Using a normative, juridical, and qualitative approach, the research examines the implementation of consumer protection principles in online transactions, with a specific focus on transparency, data privacy, unfair contract terms, and the accessibility of dispute resolution channels. The findings indicate that although several legal frameworks—such as electronic transaction laws and consumer protection statutes—have adapted to digital developments, their enforcement remains inconsistent and fragmented. Many consumers are unaware of their rights in digital transactions, while existing regulations often struggle to keep pace with the rapid pace of technological innovation. The study also reveals that dispute resolution in e-commerce is still dominated by platform-based mechanisms, which tend to prioritize business interests over consumer rights. Furthermore, cross-border transactions often create jurisdictional ambiguities that weaken consumer protection. This research makes an academic contribution by presenting a conceptual model of adaptive consumer protection, which integrates technological responsiveness, legal flexibility, and ethical accountability. It extends the theoretical discourse on digital consumer law by proposing the harmonization of international standards and the establishment of collaborative enforcement mechanisms between states and digital platforms. Practically, the study offers recommendations for policymakers and regulatory bodies to enhance consumer trust, foster digital literacy, and ensure equitable legal safeguards in the global digital marketplace.
AtıfScopus12İncele - MakaleAçık Erişim2024Scopus SJRQ1Thermal resistance of Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella in animal fat – Kinetic analysis and mathematical modeling
Ozturk, Samet; Huang, Lihan; Hwang, Cheng-An; Sheen, Shiowshuh
The objective of this study was to evaluate the effect of fat on thermal resistance of L. monocytogenes, E. coli O157:H7, and Salmonella spp. A 4-strain cocktail of each microorganism was inoculated to beef tallow and heated isothermally at temperatures between 55 and 80℃. All survival curves did not follow the 1st-order inactivation kinetics but conformed to a two-stage linear pattern. The first stage was markedly less heat-resistant than the second, as manifested by significantly lower D values. The z values of E. coli O157 H7 and Salmonella spp. were 11.8 °C and 12.3 °C in the first stage (z1) but increased to 23.7 °C and 20.8 °C in the second stage (z2), respectively. For L. monocytogenes, while the z values were similar for both stages (z1 = 19.6 °C and z2 = 18.5 °C), the second stage D values are 3.6–5.9 times of those in the first stage. One-step analysis was used to fit the nonlinear curves to the Weibull model, yielding < 1 exponents for the model (0.495, 0.362, and 0.282, respectively, for L. monocytogenes, E. coli O157:H7, and Salmonella spp.), suggesting gradually increased thermal resistance during heating. The experimental results showed that these microorganisms could resist heating for longer time and at higher temperatures in tallow than they do in regular meats containing lower levels of fat. The kinetic models can be used to develop thermal processes to properly inactivate pathogens contaminated in the fat portions of meat products or other high fat products.
AtıfScopus9WoS8OpenAlex10İncele - MakaleYalnız künye2006Scopus SJRQ2Three-directional extensional deformation and formation of the Liassic rift basins in the Eastern Pontides (NE Turkey)
Eyüboǧlu, Yener; Bektaş, Osman; Şeren, Aysel; Maden, Nafiz; Özer, Rahşan; Jacoby, Wolfgang R.
The Eastern Pontide magmatic arc (NE Turkey) was rifted by the polyphase extensional tectonic regimes in the Early Jurassic. While alternated volcanics and siliciclastic sedimentary rocks accumulated during the episodic tectonic subsidences, thermal subsidence is manifested by sedimentation of the red pelagic limestones of the Ammonitico Rosso during the Pliensbachian. The trends of the Liassic basins extending in NW-SE, E-W, NE-SW directions coincide with the gravity and magnetic lineament anomalies and corresponding fault zones that are responsible for the paleotectonic and neotectonic evolutions of the Eastern Pontide magmatic arc. These mutual relationships suggest that the faults making up the architecture of the Liassic basins might have operated during the Paleozoic, Mesozoic and Cenozoic times in different manners. Neptunian dikes, filled by the early rift siliciclastic and following fossiliferous red pelagic limestone implying the repeated extensional tectonic regimes, are also parallel to the main extensions of the Liassic basins. The poles of the contemporaneous neptunian dikes suggesting two or three extensional conjugate fracture systems are in accordance with the dip directions of the rift sediments accumulated in the same conjugate normal fault systems. Assuming that the Liassic basins with Ammonitico Rosso are coeval, multi-armed rift basins might have opened by the mode of the three-directional extension rather than reactivation of faults in the different times.
AtıfScopus91WoS83İncele - MakaleAçık Erişim2024Scopus SJRQ1Promoting sustainability in developing Countries: A Machine Learning-based approach to understanding the relationship between green investment and environmental degradation
Ahmad Khan, Khatib; Khalid Anser, Muhammad; Pala, Fahrettin; Barut, Abdulkadir; Wasif Zafar, Muhammad
The main objective of this study is to examine the impact of green investment on environmental degradation in developing countries using machine learning-based estimation combined with robustness tests of static and dynamic panel data modeling techniques. The scope of this study covers 30 developing countries for 2009–2019. This study introduces a new index of environmental degradation that uses the entropy method and includes green gas emissions and deforestation. The study addresses trade openness, the quadratic shape of economic growth, and urbanization in the context of the Environmental Kuznets Curve Hypothesis (EKC) and the Ecological Modernization Theory (EMT), in addition to green investment. This study considers the kernel-based regularized least squares (KRLS) approach, the static panel technique Driscoll & Kraay standards error method, and a dynamic panel technique system generalized moment techniques. The empirical findings from the machine learning method show that green investment significantly reduces environmental degradation with a higher coefficient resulting from the static fixed effect estimation. The study also reveals that the main hypotheses, such as EKC and EMT, are confirmed by all estimation techniques. Based on the results, the study recommends that policymakers take pragmatic steps toward green investments and increase the financing of green energy initiatives to combat environmental degradation.
AtıfScopus27OpenAlex27İncele - MakaleAçık Erişim2024Scopus SJRQ1Evaluation of Spiritual Care and Well-Being Levels of Individuals Diagnosed with Lung Cancer in Turkey
Çakmak, Seher; Demir Doğan, Melike; Selim, Nisanur; Kalleci, Gülse Nur
This study aimed to assess the spiritual care needs and spiritual well-being levels of lung cancer patients undergoing chemotherapy (CT). This descriptive cross-sectional study was conducted with 110 patients in the outpatient CT unit of a university hospital. Data were collected using a personal information form, the “Three-Factor Spiritual Well-Being Scale” and the “Spiritual Care Needs Scale.” The average age of participants was 62.6 ± 8.0 years. Patients with a university or above education level, civil servants, self-employed individuals, those receiving only CT, and those with less than 5 CT cycles had significantly higher spiritual well-being scores (p < 0.05). Spiritual care needs scale scores were significantly higher for married individuals and those receiving only CT (p < 0.05). In conclusion, both spiritual well-being levels and spiritual care needs were observed to be high among lung cancer patients.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2025Scopus SJRQ3EXCITED ELECTRON PRODUCTION AT THE SPPC-BASED ep COLLIDERS VIA CONTACT INTERACTIONS
Caliskan, A.
If a linear electron accelerator is installed into the SPPC (Super Proton–Proton Collider) complex, ep collision options will be available in addition to pp collisions. We consider the production of excited electrons with spin-1/2 at the future SPPC-based electron–proton colliders with center-of-mass energies of 8.44, 11.66, 26.68, and 36.88 TeV. In the ep → e*X → eγX signal process, excited electrons are produced by contact interactions and decay into the photon channel by gauge interactions. Taking into account the corresponding background process, the pseudorapidity and transverse momentum distributions of the final-state particles are plotted. We reported on the discovery, observation, and exclusion mass limits of excited electrons by applying appropriate kinematical cuts best suited for amplifying the signal of the excited electron signature. We also investigated the highest achievable values of the compositeness scale for the discovery of excited electrons at these colliders.
- MakaleAçık Erişim2024Scopus SJRQ2Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering
Alibeyoğlu, Fatih; Karabudak, Filiz; Yeşildal, Ruhi; Balcı, Arif; Efeoğlu, İhsan; Ateş, Onur Kazım
Despite their extensive use in the automotive and aerospace industries, Mg and Mg alloys, which are light metals, exhibit low fatigue and tensile strength. In this study, transition metal-nitride (TMN) multilayer coatings (Ti+TiN+Ti+TiVN) were coated twice on AZ91 Mg alloy using a Confined Field Unbalanced Magnetron Sputtering (CFUBMS) system to increase fatigue and tensile strength. The structural properties of the films were analyzed by using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometry (EDS) methods, and the mechanical properties were analyzed by rotating bending fatigue and tensile testing machines. Ti+TiN+Ti+TiVN multilayer nitride surface coatings on AZ91 Mg alloys showed a dense and columnar microstructure and according to XRD results (111) was the preferred orientation with the dominant peak. The fatigue limit value of the AZ91 base material was fixed at 60.46 MPa, while it increased to 68.48 MPa after being coated with multilayer nitride. Along with the multilayer nitride coating, the tensile strength increased from 169.98 MPa to 175.43 MPa. As a result, the multilayer hard nitride coating with low surface roughness, which fills the defects, notches, and voids on the surface of the AZ91 base material, increased the fatigue and tensile strength in parallel. Based on the outcomes of the research, the literature has been enriched with an innovative approach through the enhancement of fatigue and tensile strengths by applying a CFUBMS coating to lightweight metals and alloys, such as AZ91, especially in the transportation industry where lightness and dynamic load resistance are essential.
AtıfScopus4WoS4OpenAlex2İncele - MakaleAçık Erişim2024Scopus SJRQ1Improving radio frequency heating uniformity in peanuts: Effects of packaging geometry, electrode gap, particle size and interlayer displacement process
Tasci, Caner; Liu, Shuxiang; Erdogdu, Ferruh; Ozturk, Samet
This study aimed to assess the impact of various processing parameters including electrode gap, packaging geometry, and particle size on the heating efficiency of radio frequency (RF) processing for peanut thermal decontamination. In addition, interlayer displacements were presented to evaluate the effect of the mixing on heating uniformity. Experimental studies were carried out using 3D-printed polylactic acid (PLA) containers (square, rectangular, and cylindrical) to place the peanut samples with particle sizes ranging from 0.71 to 2.00 mm at 100–140 mm electrode gaps. Temperature changes within the samples were monitored using fiber optic sensors and surface temperature distributions were determined with an infrared camera. Heating uniformity index (λ) was then calculated to assess the effects of RF processing conditions on RF heating uniformity. Results showed that the cylindrical container exhibited a more consistent and uniform heating profile (λ = 0.12) with 1.58 °C min−1 heating rate compared to other containers, and a single interlayer displacement between top and bottom layers further improved temperature distribution uniformity. Smaller particle sizes also led to faster heating rates from 1.71 to 1.55 °C min−1 with more uniform heating due to the reduced porosity within the particles with increased thermal conduction and electromagnetic energy absorption. This study presented valuable insights for developing an effective RF process as an alternative to conventional thermal treatments for decontamination of low-moisture, high-fat particulate foods. Industrial significance: This research presented an innovative approach applying RF heating for a possible decontamination process for peanut samples. The research tackled the growing worldwide consumer demand for food products to satisfy food safety regulations while peanuts were selected to demonstrate the process effect due to the recent food safety issues in peanut butter considering that a pre-process for decontamination would lead to a decrease in the resulting safety issues.
AtıfScopus21WoS20OpenAlex20İncele - MakaleAçık Erişim2025Scopus SJRQ2Effects of inspiratory muscle training on 1RM performance and body composition in professional natural bodybuilders
Çelikel, Baha Engin; Yılmaz, Coşkun; Demir, Alper; Sezer, Süreyya Yonca; Ceylan, Levent; Ceylan, Tülay; Tan, Çetin
Background: The effect of inspiratory muscle training on upper limbs One Rep Maximum (1RM) in professional natural bodybuilders is still unclear. Our aim of this study is to investigate the effects of a 6 weeks inspiratory muscle training on 1RM results. Methods: This study included 14 athletes, that had participated in international bodybuilding competitions. Each athlete had been training for minimum of 5 years and at least 5 h per week. The participants were randomly divided into two groups: inspiratory muscle training (IMT) and control (CON) groups. The IMT group and CON group consisted of seven subjects. While the control group continued with the normal training regime, the IMT group additionally performed inspiratory muscle training with the resistance setting of the PowerBreathe® Classic device set to 40% of the participant’s MIP. Prior to and during the 6-week training period, the bench press 1 RM, anthropometry, pulmonary function tests, and maximal inspiratory (MIP) and expiratory (MEP) pressure measurements were obtained. A nutrition protocol developed by a qualified dietician was implemented for each athlete. Results: The mean maximal strength of the respiratory muscle training group changed by 14.39%, whereas that of the control group changed by 9.43% (p = 0.012). The changes in the mean FVC (p = 0.000), FEV1 (p = 0.001), PEF (p = 0.064), MIP (p = 0.001), and maximal expiratory pressure (p = 0.017) were greater in the IMT group. The mean circumferences of the shoulder (p = 0.004), chest (p = 0.008), arm (p = 0.004), and neck (p = 0.003) improved more in the IMT group than in the CON group. A reduction in abdominal measurement was observed in the IMT group (p = 0.039), whereas no notable discrepancy was identified in body fat percentage (p = 0.295). Conclusion: In conclusion we identified that the addition of progressive loading inspiratory muscle training for competition preparation programs in professional natural bodybuilders will further improve their respiratory function, respiratory muscle strength, maximal strength, and muscle development. This research provides valuable insights into how IMT influences bodybuilding training outcomes, potentially guiding future interventions and program designs to better support strength development and body composition in bodybuilding training contexts.
AtıfScopus12WoS13OpenAlex14İncele - MakaleAçık Erişim2025Scopus SJRQ1Effect of heating rate on thermal inactivation kinetics of Escherichia coli O157:H7 in ground beef
Ozturk, Samet; Huang, Lihan; Hwang, Cheng-An; Sheen, Shiowshuh
The objective of this study was to investigate the effect of heating rate on thermal inactivation kinetics of microorganisms in food, testing the survival of Escherichia coli O157:H7 in ground beef during isothermal and dynamic heating. A 4-strain cocktail of E. coli O157:H7 was inoculated to irradiation-sterilized ground beef (10 % fat) and then subjected to isothermal heating (55–63 °C) and dynamic heating (20–63 °C). One-step analysis was used to determine the kinetic parameters. Different degrees of increased thermal resistance were observed in E. coli O157:H7 during dynamic heating. In comparison to isothermal heating, slight increase in the thermal resistance was found during fast heating (1.2–1.8 °C/min). However, slow heating (0.3–0.9 °C/min) led to significantly increased thermal resistance due to heat adaption at temperatures below 61.3 °C, but E. coli O157:H7 became more sensitive to heat above this temperature, suggesting that the increased resistance may diminish after reaching a critical temperature. To account for the increased heat resistance during dynamic heating, a unified kinetic model was developed and validated by applying one-step dynamic analysis, resulting in more accurate kinetic parameters to describe the survival curves of all heating rates. This study demonstrated that the kinetic parameters derived from isothermal conditions may not be applicable to dynamic conditions. It is necessary to consider the effect of heating rate and to determine the thermal inactivation kinetic parameters under dynamic conditions. It also demonstrated the advantage of using one-step dynamic analysis for evaluating thermal processes. The results of this study may be particularly useful for designing slow-heating processes to ensure proper cooking of products.
AtıfScopus6WoS5OpenAlex6İncele - MakaleYalnız künye2025Scopus SJRQ2Optimization of steel diffusion bonding processes using the Taguchi method
Serkan Yıldırım, Mehmet; Aydın, Kemal; Kalyon, Ali; Kaya, Yakup
This study examines the diffusion bonding behavior between 316L stainless steel and H13 tool steel, focusing on the effects of key process parameters. Specifically, the influence of bonding pressure, bonding temperature, and holding time on joint quality and mechanical performance is systematically investigated. The Taguchi optimization method was employed to determine the optimal bonding conditions, with shear strength serving as the primary performance indicator. The bonding interfaces were characterized through scanning electron microscopy to analyze microstructural evolution and diffusion behavior. Analysis of variance was conducted to assess the influence of process parameters on shear strength, identifying temperature as the most significant factor. The optimum shear strength was experimentally validated, and a confidence interval was calculated to ensure statistical reliability. The results demonstrated that higher bonding temperatures and moderate pressures led to improved diffusion at the interface, enhancing joint integrity. The findings contribute to a better understanding of the diffusion bonding process and its potential for high-performance applications in aerospace, biomedical, and tooling industries.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ1Post-seismic structural assessment: advanced crack detection through complex feature extraction using pre-trained deep learning and machine learning integration
Reis, Hatice Catal; Turk, Veysel; Ustuner, Mustafa; Kaya Yildiz, Cagla Melisa; Tatli, Ramazan
Earthquakes can often cause significant damage to buildings. After an earthquake, experts/managers need to make quick and accurate damage assessments. Traditionally, manual analysis processes have been widely used in damage assessment studies. The fact that these methods are time-consuming and based on human observation leads to certain limitations in damage assessment studies. In recent years, artificial intelligence techniques such as deep learning and machine learning have frequently been preferred in damage detection studies, and significant success has been achieved. This study aimed to automatically detect cracks/damages in the buildings in Diyarbakir city after the February 6, 2023 Kahramanmaras, Turkey earthquake. Our experimental dataset was collected by the researchers and named Kahramanmaras-Diyarbakir Earthquake Building Crack Dataset (KDBECD-2023). The data set consists of four categories in terms of damage level: undamaged, slightly damaged, moderately damaged, and heavily damaged buildings. DenseNet201 deep learning architecture and popular machine learning algorithms, Support Vector Machine, Random Forest, Decision Tree, and K-Nearest Neighbors (KNN) were used to classify cracks at different damage levels. In the experimental phase, feature extraction was performed with the DenseNet201 architecture. In addition, dimensional reduction was applied with the Principal Component Analysis method to reduce the computational complexity of the proposed hybrid study. According to the experimental results, the DenseNet201-KNN hybrid model gave the most successful result with an accuracy value of 94.62%. The results of this study can make important contributions to decision makers and experts in detecting cracks and damages in buildings after an earthquake.
AtıfScopus6WoS4OpenAlex5İncele - MakaleAçık Erişim2025Scopus SJRQ1Investigation of the effects of mainshock-aftershock sequences on the dynamic responses of pipeline considering soil-pipeline interaction
Ozturk, Kasif Furkan
Pipelines are important structural elements that are frequently used today to meet many infrastructures needs such as drainage, natural gas or water transmission. In this context, the usability of such structures, which are important elements of infrastructure systems, especially after disasters such as earthquakes, is of great importance. For this reason, within the scope of this study, a parametric investigation of the seismic behaviors of a natural gas pipeline system under mainshock-aftershock sequences have been carried out, specifically taking into account the soil-natural gas pipeline interaction (SNGPI) in the help of finite element model (FEM) proposed. Before developing the model of SNGPI system proposed using solid element, the fundamental mode frequencies of the pipeline system modeled using the solid element for the verification have been compared with those of obtained from the pipeline system modeled using the beam element and the analytical solutions. After verification of proposed model is demonstrated, SNGPI system has been modeled and its fundamental modes have been compared with mode frequencies of soil stratum obtained from well-known simple analytic solutions. After this stage, the dynamic analyses of natural gas pipeline (NGP) system in the time domain have been carried out using four different soil systems and four different mainshock-aftershock sequences. The results of the nonlinear time-history analyses have been investigated in terms of the stress and the displacement responses. Parametric evaluations show that the greatest displacements and the stresses occurring at the considered nodes of NGP system may be importantly affected from mainshock-aftershock sequences and soil stiffness changes. As the soil stiffness decreases, both the peak stresses and displacements increased significantly. On the other hand, the same responses obtained under mainshock loadings, which have relatively lower peak ground acceleration (PGA)/peak ground velocity (PGV) ratio compared to aftershock loadings, are generally larger than those obtained under aftershock loadings.
AtıfScopus7WoS6OpenAlex9İncele - MakaleAçık Erişim2025Scopus SJRQ1Soil Amplification and Code Compliance: A Case Study of the 2023 Kahramanmaraş Earthquakes in Hayrullah Neighborhood
Avcı, Eyübhan; Afacan, Kamil Bekir; Deveci, Emre; Uysal, Melih; Altundaş, Suna; Balcı, Mehmet Can
In the earthquakes that occurred in the Pazarcık (Mw = 7.7) and Elbistan (Mw = 7.6) districts of Kahramanmaraş Province on 6 February 2023, many buildings collapsed in the Hayrullah neighborhood of the Onikişubat district. In this study, we investigated whether there was a soil amplification effect on the damage occurring in the Hayrullah neighborhood of the Onikişubat district of Kahramanmaraş Province. Firstly, borehole, SPT, MASW (multi-channel surface wave analysis), microtremor, electrical resistivity tomography (ERT), and vertical electrical sounding (VES) tests were carried out in the field to determine the engineering properties and behavior of soil. Laboratory tests were also conducted using samples obtained from bore holes and field tests. Then, an idealized soil profile was created using the laboratory and field test results, and site dynamic soil behavior analyses were performed on the extracted profile. According to The Turkish Building Code (TBC 2018), the earthquake level DD-2 design spectra of the project site were determined and the average design spectrum was created. Considering the seismicity of the project site and TBC (2018) criteria (according to site-specific faulting, distance, and average shear wave velocity), 11 earthquake ground motion sets were selected and harmonized with DD-2 spectra in short, medium, and long periods. Using scaled motions, the soil profile was excited with 22 different earthquake scenarios and the results were obtained for the equivalent and non-linear models. The analysis showed that the soft soil conditions in the area amplified ground shaking by up to 2.8 times, especially for longer periods (1.0–2.5 s). This level of amplification was consistent with the damage observed in mid- to high-rise buildings, highlighting the important role of local site effects in the structural losses seen during the Kahramanmaraş earthquakes.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYalnız künye2025Scopus SJRQ2The effect of welding parameters on weld bead geometry in gas tungsten arc welding applications by response surface methodology model
Yildirim, Mehmet Serkan; Ayhan, Emre; Aydin, Kemal; Durgutlu, Ahmet
This study examines the effects of tungsten electrode sharpening angle, torch angle, and arc length on weld bead geometry in gas tungsten arc welding (GTAW). Low-carbon steel plates (4 mm thickness) were welded using ER70S-6 filler wires (2 mm diameter). Experimental analyses and response surface methodology (RSM) revealed that increasing the electrode sharpening angle enhances penetration depth, while reducing the torch angle widens the bead. Longer arc lengths decrease penetration but increase bead width. Validation tests confirmed the accuracy of the RSM models, showing an average deviation of 1.14%. Analysis of variance highlighted the statistical significance of linear, quadratic, and interaction terms in the models. The findings provide critical insights for optimizing GTAW parameters, improving weld quality, and advancing process control, thereby contributing both practical and academic value to welding research.
AtıfScopus2WoS4OpenAlex4İncele
