Yayınlar
Koleksiyondaki öğeler
- MakaleAçık Erişim2025Scopus SJRQ1Kurtun Dam oscillate characterization with landslide possible effect detection using InSAR observations
Celik, Fatih; Sanli, Fusun Balik; Celik, Kemal; Celik, Ayse
Observing and analyzing areas prone to landslides is crucial due to the extensive destructive capacity of landslides. To monitor landslide activities across diverse areas, remote sensing data and image processing methods are employed. This study proposes a method that integrates Multi-temporal Interferometric Synthetic Aperture Radar and advanced temporal tracking technologies to intensify surveillance of the Kurtun Dam and its valley. According to Sentinel-1 A data, the net displacement rates of the dam crest varied between − 12 and 2 mm/year (LOS). InSAR technology surveys the entire dam catchment area, detecting critical infrastructure such as slopes, spillways, and access roads. The crest of the Kurtun Dam experiences oscillatory deformation during filling activities, but the lateral slopes and downstream abutment remain stable. As reservoir water levels rise, the dam structure exhibits downstream deformations, whereas declining water level results in upstream displacements. Monitoring points located the opposite Ozkurtun settlement and within the reservoir area, both facing the dam, exhibited displacement rates of up to -50 mm monthly. In regions susceptible to landslides, the greatest annual displacement rates were observed to be -54 and − 127 mm/year. This study suggests that integrating 3D modeling with InSAR technology into dam monitoring systems can significantly enhance their effectiveness. At Kurtun Dam and other crucial locations within the catchment area, the integrated approach combined with topographic monitoring, ensures reliable landslide detection and analysis. By advancing monitoring technology for embankment dams, this strategy prioritizes safety and structural integrity assessments.
AtıfScopus1WoS1OpenAlex2
İncele - Kitap BölümüYalnız künye2025A theoretical framework of renewable energy financing
Soydas, Safak Sonmez
The renewable energy sector is an area that has received increasing attention in recent years and has significant growth potential worldwide. Factors such as limited traditional energy sources, environmental concerns, and climate change encourage using renewable energy sources. In this context, financing renewable energy companies has also gained great importance. Financing is a fundamental requirement for the implementation and expansion of renewable energy projects. However, the fact that renewable energy projects are generally high-cost and have long payback periods makes financing these projects difficult. Therefore, research on the financing of renewable energy companies is extremely important to understand and support the development of the sector. This study intends to ensure a theoretical viewpoint on the financing of renewable energy companies. The study will evaluate the general situation of the renewable energy sector, emphasize the importance of financing, and go over the impression of divergent financing sources on companies' growth strategies. Additionally, recommendations will be presented on the financing challenges faced by renewable energy companies and how these challenges can be overcome.
- Kitap BölümüYalnız künye2025Applying RATMI (Ranking by Alternatives Trace to Median Index) for Ranking Countries Based on Sustainability Performance
Simsek, Ahmet Bahadir; Simsek, Aybala
Today, global problems such as climate change, resource depletion and social inequality motivate the need for tools that can be used to measure the sustainability performance of countries. In this section, a new MCDM approach, RATMI (Ranking by Alternatives Trace to Median Index), is proposed with this motivation. RATMI uses trace and median similarity techniques to provide a balanced and accurate ranking as the median minimises the effect of outliers. In this chapter, the RATMI method is used to assess the sustainability performance of 157 countries for the period 2016-2020 on the basis of economic, social and environmental dimensions. The contributions of this study include the potential to promote RATMI as an effective tool for sustainability assessment of countries, identify role models, and inform policymakers on the development of sustainability strategies at the global level. This practice not only advances the literature on MCDM in sustainability assessments, but also provides a practical framework to guide future policy and research aimed at promoting sustainable development.
AtıfOpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ3Cosmetological potential of the essential oil from the aerial parts of Rubus sanctus Schreb.: Enzymatic inhibition, antibacterial properties, and chemical composition
Yıldırım, Aybeniz; Celep, İnci Kurt; Gül, Abdulkadir
Recently, skin care products and cosmetic preparations with herbal ingredients have attracted considerable interest from the public. Therefore, the cosmetic industry is investigating natural products like essential oils and extracts. This study aimed to determine the anti-aging effects of the essential oil obtained from the aerial parts of Rubus sanctus Schreb. (RsEO), as well as to reveal its chemical composition and investigate its antibacterial activity. The chemical composition of RsEO was determined by using GC-MS. The anti-aging activity of RsEO was evaluated by in vitro studies of anti-collagenase, anti-elastase, anti-tyrosinase, and anti-hyaluronidase activities. The antibacterial potential of RsEO was investigated by the agar-well diffusion method against Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. RsEO showed significant inhibition against collagenase, elastase, hyaluronidase, and tyrosinase with IC50 values of 80.46, 77.85, 72.71, and 82.71 μg/mL, respectively, and when compared with the positive controls epigallocatechin gallate (IC50: 38.91 μg/mL for collagenase, IC50: 38.91 μg/mL for elastase), tannic acid (IC50: 26.95 μg/mL for hyaluronidase), and kojic acid (IC50: 28.74 μg/mL for tyrosinase), the activities were found to be close. It was determined that the major components of RsEO were pentadecanal (8.88%), dodecanoic acid (7.86%), nonanal (4.32%), and octadecanal (4.08%). RsEO showed moderate antibacterial activity (inhibition zones between 10 and 15 mm) against the tested bacteria compared to ampicillin. This study demonstrated that RsEO is a natural product that has the potential to serve as a promising anti-aging and antibacterial therapeutic agent due to the synergistic effect of its constituent components.
AtıfScopus3WoS3OpenAlex4İncele - MakaleAçık Erişim2025Scopus SJRQ1DSCIMABNet: A novel multi-head attention depthwise separable CNN model for skin cancer detection
Reis, Hatice Catal; Turk, Veysel
Skin cancer is a common type of cancer worldwide. Early diagnosis of skin cancer can reduce the risk of death by increasing treatment success. However, it is challenging for dermatologists or specialists because the symptoms are vague in the early stages and cannot be noticed by the naked eye. This study examines digital diagnostic techniques supported by artificial intelligence, focusing on early skin cancer detection and two methods have been proposed. In the first method, DSCIMABNet deep learning architecture was developed by combining multi-head attention and depthwise separable convolution techniques. This model provides flexibility in learning the dataset's local features, abstract concepts, and long-term relationships. The DSCIMABNet model and modern deep learning models trained on ImageNet are proposed to be combined with the ensemble learning method in the second method. This approach provides a comprehensive feature extraction process that will increase the performance of the classification process with ensemble learning. The proposed approaches are trained and evaluated on the ISIC 2018 dataset with image enhancement applied in preprocessing. In the experimental results, DSCIMABNet achieved 84.28% accuracy, while the proposed hybrid method achieved 99.40% accuracy. Moreover, on the Mendeley dataset (CNN for Melanoma Detection Data), DSCIMABNet achieved 92.58% accuracy, while the hybrid method achieved 99.37% accuracy. This study may significantly contribute to developing new and effective methods for the early diagnosis and treatment of skin cancer.
AtıfScopus26WoS17OpenAlex26İncele - MakaleAçık Erişim2025Scopus SJRQ3Biological activities and phenolic content of endemic Helichrysum artvinense P.H. Davis et Kupicha (Asteraceae)
Acet, Tuba; Özcan, Kadriye; Kalmuk, Nursen Aksu
Species from the Asteraceae family have been extensively utilized in traditional medicine and as food sources for centuries. They also exhibit important biological activities attributed to their diverse array of phytochemical compounds. This research aimed to determine total phenolic and flavonoid contents of ethanol (EtOH) and methanol (MeOH) extracts of endemic Helichrysum artvinense and to reveal its antioxidant, antimicrobial enzyme inhibitory (α-glucosidase, α-amylase, and tyrosinase) and DNA protective activities. In addition, phenolic compound analyses were conducted using high-performance liquid chromatography (HPLC), establishing a correlation with the aforementioned biological activities. Based on the obtained data, the ethanol (EtOH) extract of the plant demonstrated greater prominence in terms of the screened biological activities. This extract was found to contain significant phenolic components, including epicatechin, chlorogenic acid, and luteolin. Consequently, it appears that the plant has the potential to serve as a natural alternative in both food and pharmacological applications. However, further studies to elucidate the mechanisms underlying the observed biological activities would be beneficial for the product development phase.
- MakaleAçık Erişim2024Determination of Antioxidant Capacities of Extracts of Sorbus subfusca (ledeb. ex. nordm.) boiss
Kocabaş, Selahattin; Topal, Fevzi
Sorbus subfusca (ledeb. ex. nordm.) boiss. (Sorbus subfusca) belongs to the Rosacese family. It is commonly referred to as highland rowan. It is an endemic species found only in the eastern Black Sea Region of Turkey and in a few countries on the Asian Continent. Both water (WESS) and ethyl alcohol (EESS) lyophilized forms were used as extracts. Different reducing capacity methods and radical scavenging activity methods were used to study the antioxidant activities of the extracts. Total phenolic compounds were calculated as 43.5 (WESS) and 43.0 (EESS) µg GAE/mg extract. This value is an indication that it can take place in plants with high phenolic content. Peroxidation inhibition percentages of linoleic acid emulsion at 20 µg mL-1 concentration for WESS and EESS; WESS was calculated as 70.93% and EESS as 82.63%. The high antioxidant capacity of Sorbus subfusca, an endemic species, brings up the preference of natural products as antioxidants. It is thought that these studies will draw a new path to the literature, especially alternative medicine and pharmacological studies.
AtıfScopus1OpenAlex2TR Dizin1
İncele - MakaleYalnız künye2024Scopus SJRQ1Remote sensing and monitoring of water resources: A comparative study of different indices and thresholding methods
Günen, Mehmet Akif; Atasever, Umit Haluk
Water resources are essential for the ecological system and the development of civilization. Water is imperative factor for health preservation and sustaining various human activities, including industrial production, agriculture, and daily life. Remote sensing provides a cost-effective and practical means to detect and monitor water bodies, offers valuable insights into the impact of climatic events on water structures, especially in coastal lake regions. The research primarily utilizes Landsat-9 OLI-2 satellite images to evaluate the effectiveness of various water indices (WRI, NWI, MNDWI, NDWI) in combination with global automatic thresholding methods (K-Means, Zhenzhou's, Adaptive, Intermodes, Prewitt and Mendelsohn's Minimum, Maximum Entropy, Median, Concavity, Percentile, Intermeans, Kittler and Illingworth's Minimum Error, Tsai's Moments, Otsu's, Huang's fuzzy, Triangle, Mean, IsoData, Li's). The study was carried out on Lake Nazik, Lake Iznik, and Lake Beyşehir, which have unique geographical characteristics, and examined the adaptability and robustness of the selected indices and thresholding methods. MNDWI consistently stands out as a robust index for water extraction, delivering accurate results across different thresholding methods in regions all three lakes. As a result of quite extensive analysis, it is obtained that MNDWI and NDWI are reliable choices for water feature extraction in various lake environments, but the specific index should consider the thresholding method and unique lake characteristics. The Minimum thresholding method stands out as the most effective thresholding technique, demonstrating impressive results across different lakes. Specifically, it achieved an average Peak Signal-to-Noise Ratio (PSNR) of 78.97 and Structural Similarity Index (SSIM) of 99.37 for Lake Nazik, 74.08 PSNR and 98.34 SSIM for Lake Iznik, and 63.96 PSNR and 93.61 SSIM for Lake Beyşehir.
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İncele - MakaleAçık Erişim2024Scopus SJRQ1Experiences of Turkish mothers of children with autism: a phenomenological study
Aktaş, Eda; Ustuner Top, Fadime; Uzun, Sevda
The study aimed to explore mothers’ experiences of children with autism using a phenomenological approach. Semi-structured, in-depth interviews were conducted with 18 parents with children attending a special education centre in a northern province of Turkey. Criterion sampling, a form of purposive sampling, was employed to select participants. Interviews continued until data saturation was achieved. All interviews were audio-recorded and transcribed verbatim. Thematic analysis was utilized to analyze the data, and the study adhered to the COREQ checklist for reporting qualitative research. As a result of analyses, three main themes (the process of diagnosis, the effect of the child’s illness on parents and their challenges over time, and considerations regarding the child’s educational journey) and eight sub-themes (feelings and thoughts, reflections on the causes, reactions encountered, emotional effects, social effects, physical effects, perception of social support, and expectations from the educator and the education process) emerged. The study concluded that mothers of children with autism are emotionally, physically, and socially impacted by their child’s condition, facing considerable challenges in coping. In light of these findings, it is recommended that policymakers in our country develop plans that address the difficulties expressed by participants, review and potentially enhance financial and social support for families, and consider increasing special education hours.
AtıfScopus5WoS5OpenAlex5İncele - Kitap BölümüYalnız künye2025Determination of Criteria for Selection of Candidate Sites for Temporary Debris Storage
Aktaş, Esra; Atmaca, Ediz
Disasters are difficult-to-control situations that have a profound impact on human life and result in significant material and moral losses. Disasters occur suddenly and frequently without warning, resulting in increased losses both during and after the situation. By making plans and taking the necessary precautions, natural and human hazards can be mitigated or avoided. Disaster management plans are being prepared all over the world, including various actions for disaster preparedness, disaster response and post-disaster. The importance and necessity of disaster management plans cannot be ignored in Türkiye, which has frequently encountered disasters from past to present and suffered great loss of life and property. Disaster management is the process by which society, all organizations, and resources work together to reduce or prevent harm before, during, and after a disaster. In this context, the study aimed to determine the criteria required for the selection of candidate areas for temporary debris storage sites, which are very important after the disaster. The importance weights of the criteria obtained through literature research were determined by soliciting expert opinions via the Analytic Hierarchy Process (AHP) method, which is one of the multi-criteria decision-making methods. The criteria with the highest importance weight are listed.
- MakaleYalnız künye2025Scopus SJRQ2Determination of selection-focused physicochemical properties in the local Eğrisap pear (Pyrus communis L.) clone grown in Rize
Kalkisim, Ozgun; Aydin, Mehmet Zahit; Ozdes, Duygu; Duran, Celal
Turkey, located within the Western Asia gene center, is a significant genetic center for many fruit species, including pears. Rize, a province in the Northeastern part of Turkey, is located within the Northeast Anatolia Region, which falls within the genetic center area where pears have undergone evolutionary development. This study aimed to identify promising local Eğrisap pear clone genotypes with superior traits and to introduce them into economic use. For this purpose, Rize province and its districts were surveyed, and fruit and leaf samples were collected from pre-selected Eğrisap pear clone types. These samples were subjected to pomological, morphological, and chemical analysis. The JMP 13 statistical software package was used to compare the Eğrisap pear clone types. According to the research results, the pomological and morphological traits of the clone types varied as follows: fruit weight (99.10–139.54 g), fruit width (54.52–65.41 mm), fruit length (57.58–68.83 mm), fruit stem length (50.75–59.50 mm), fruit stem thickness (2.36–2.91 mm), core width (5.15–7.55 mm), core length (9.73–14.51 mm), flesh firmness (3.61–7.13 lb), seed number (5.30–8.55), leaf width (45.80–60.04 mm), leaf length (64.53–82.37 mm), petiole length (37.04–60.99 mm), petiole thickness (0.83–1.20 mm), and soluble solid content (SSC) (9.10 %-16.0 %). Regarding chemical composition, the pH values of the clone types ranged from (3.78–4.22), titratable acidity (0.22 %-0.47 %), protein content (1.50 %-4.95 %), vitamin C content (0.92–2.28 mg/100 g), ash content (1.16 %-4.30 %), and total sugar content (9.66 %-17.28 %). Mineral element analysis of the local pear varieties revealed that iron content ranged from (0–14.7 µg/g), copper (2.90–9.12 µg/g), manganese (2.9–11.6 µg/g), magnesium (321.7–771.5 mg/g), zinc (0 µg/g), sodium (9.6–39.6 µg/g), potassium (5.43–14.50 µg/g), calcium (50.1–219.7 µg/g), cobalt (0.01–0.31 µg/g), cadmium (0–0.1 µg/g), and nickel (0.08–4.41 µg/g). Among the local Eğrisap pear clones grown in Rize, clone type 53 IYD 01 was identified as having the most superior quality criteria and chemical composition. Consequently, it is recommended that this clone type be introduced to producers for cultivation.
AtıfScopus1İncele - MakaleAçık Erişim2025Scopus SJRQ3Cardiovascular Findings and Effects of Caffeine on Experimental Hypothyroidism
Yuksel, Duygu; Ozmen, Ozlem
Background: Thyroid hormone deficiencies can disrupt organ functions, significantly impacting the cardiovascular system. Recently, the effects of thyroid hormones on the heart have garnered increased attention. However, most studies are conducted on humans using clinical data, while cellular-level and experimental studies remain limited. Objective: This study aimed to investigate the cardiovascular implications of hypothyroidism and evaluate the impact of caffeine on cardiac health in rats induced with hypothyroidism using propylthiouracil (PTU). Methods: The study involved 60 rats divided into six groups. Group 1 served as the untreated control. Group 2 received PTU for two months to induce hypothyroidism. Group 3 received PTU for one month, followed by caffeine for one month. Group 4 received caffeine for two months. Group 5 received both PTU and caffeine simultaneously for two months. Group 6 received PTU for one month, followed by one month under normal conditions. Results: During necropsy, normal thyroid glands were observed in Groups 1, 4, and 6, enlarged thyroids in Group 2, and smaller thyroids in Groups 3 and 5. Microscopic examination revealed varying thyroid histologies: Group 2 showed significant epithelial cell proliferation and absent colloid, while Groups 3, 5, and 6 had altered yet colloid-containing acini. Macroscopic inspection of hearts appeared normal across all groups. However, histopathological examination revealed significant hyperemia and microhemorrhages in Group 2, contrasting with normal findings in other groups. Immunohistochemical analysis indicated reduced cardiac troponin expression in Group 2, while other groups maintained prominent expression. Additionally, Group 2 displayed increased serum TSH levels and decreased T3 and T4 levels. Conclusion: The findings suggest that administering caffeine alongside or after PTU treatment in rats with experimentally induced hypothyroidism may ameliorate thyroid and cardiac irregularities. This study indicates caffeine's potential in mitigating the adverse effects of hypothyroidism on thyroid and heart health.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2024Scopus SJRQ1Evaluation of turbulence models for the prediction of flow properties in vegetated channels
Sibil (Şibil), Rahim
The performance of turbulence models was investigated to predict the flow and turbulence features of the vegetated channel using computational fluid dynamics (CFD). The Ansys Fluent, CFD software was implemented for the numerical studies. The flow was three-dimensional, incompressible, steady, and turbulent. Ten turbulence models, provided by Ansys Fluent, were implemented for the comparative study. The numerical model was validated against an experimental study conducted in the literature. The numerical studies show that the Renormalization group k-ϵ model is the most successful model for predicting the flow characteristics of the vegetated channel with a Root Mean Square Error (RMSE) value of 0.2752. At the same time, the Reynolds Stress Model gives the least successful predictive performance, indicated by an RMSE value of 0.4302. Moreover, the Spalart-Allmaras (S-A) model offers the shortest computation time with a value of 6652.393 s, whereas the Shear Stress Transport k-ω model proves to be the most time-consuming with a value of 11 952.219 s. The velocity of water flow in a channel is not uniform as it is slower at the surface of leaves and faster in the free zones. The maximum velocity is observed in the middle section of the channel, below the leaf, and between the roots with the value of u = 0.1158 m/s. Furthermore, the characteristics of turbulence in a channel are influenced by several factors such as channel geometry, flow velocity, and vegetation distribution. As a result, the presence of vegetation in a channel affects the flow and turbulence characteristics of the water significantly.
AtıfScopus3OpenAlex1İncele - MakaleAçık Erişim2025Scopus SJRQ2Factors Affecting the Mental Health of Youth After the Great Kahramanmaras Earthquake Disaster
Türkkan, Tuğba; Hatipoğlu, Ertuğrul
This study aims to determine the extent of the psychological effects of the Kahramanmaraş earthquake disaster, which is widely regarded as one of the most significant disasters of the century, on young people based on their direct or indirect exposure and to investigate the impact of these issues on life satisfaction. Data were collected from 337 individuals who were continuing their advanced education at a state university in Turkey, using a demographic information form, life satisfaction scale and Depression Anxiety Stress Scales 21. In the analysis of the data, t-test, Pearson correlation test, ANOVA and multiple regression analysis were employed. The results of the analyses indicated that as the intensity of exposure to disaster news increased, the stress, depression, and anxiety levels of the participants also increased. Individuals who experienced the earthquake personally and participated in volunteer aid activities demonstrated higher depression and anxiety scores and DASS21 scale total scores than those who did not directly experience the earthquake but followed the news and those whose relatives experienced the earthquake. There was no significant difference in the intensity of following earthquake news between men and women among the participants. However, it was determined that the intensity of following earthquake news from media and social media tools positively and significantly predicted the life satisfaction of the participants. These findings provide insights for future mental health interventions and social work practices for young people affected by the earthquake.
AtıfScopus4WoS6OpenAlex6İncele - BildiriYalnız künye2025Hybrid CNN-LSTM Framework for Automated Detection of Pediatric Heart Murmurs
Al-Taib, Asmaa Abduh; Ture, Hayati; Aslan, Muhammed Emin
This study presents a comprehensive deep learning framework for automated heart murmur detection from phonocardiogram (PCG) signals to address the subjective limitations of cardiac auscultation. Using the CirCor DigiScope dataset of 5,272 pediatric heart sound recordings from 1,568 subjects, we systematically evaluated multiple approaches including traditional machine learning models (Logistic Regression, SVM, KNN, Decision Tree, AdaBoost), basic deep learning architectures (standalone CNN and LSTM), and advanced transfer learning models (DenseNet121, EfficientNet B0/B1/B2, ResNet 50/101, MobileNet V2/V3, GhostNet, AttentionCNN). Our hybrid CNN-LSTM architecture combines mel-spectrogram spatial feature extraction with temporal sequence modeling using 128 traditional audio features and comprehensive preprocessing with data augmentation. The CNN-LSTM model achieved superior performance with 84.6% accuracy, 0.84 F1-score, 0.748 precision, and 0.800 recall, significantly outperforming traditional methods (best SVM: 0.716 F1-score) and advanced architectures (best DenseNet121: 0.72 F1-score), demonstrating robust classification with 0.879 AUC. Results indicate that hybrid deep learning architectures effectively automate cardiac auscultation, providing objective diagnostic tools with potential for improved healthcare accessibility and clinical decision-making.
- MakaleAçık Erişim2025Scopus SJRQ3MOHO DEPTH IN THE SOUTH CASPIAN BASIN ESTIMATED FROM GRAVITY FIELD DATA AND LOCATION OF HYDROCARBON RESERVOIRS
Kadirov, F.A.; Safarov, R.T.; Gahramanov, M.R.; Maden, N.M.
The South Caspian Basin (SCB) is a geologically complex and diverse region of significant scientific interest due to its hydrocarbon resources and intricate crustal structure. This study provides an updated interpretation of the SCB’s crustal configuration using gravity-derived data, with particular emphasis on delineating Moho depth and the influence of its variations on petroleum basins. The crustal structure of the basin is assessed using Bouguer gravity anomalies, incorporating terrestrial and marine gravity measurements, and processed with spectral analysis methods. Power spectrum analysis was applied to estimate the depths of subsurface mass distributions affecting the gravity field, enabling separation of regional and residual anomalies and providing an initial reference depth of Moho. These results served as input for Parker–Oldenburg inversion, an iterative Fourier-based technique used to model the Moho surface by minimizing discrepancies between observed and calculated gravity anomalies. The integrated approach reveals substantial lateral variations in Moho depth, ranging from approximately 42 km in the Absheron–Prebalkhan zone to about 29 km in the central SCB. Analysis of spatial correlations indicates that oil and gas reservoirs are primarily located in areas where the Moho surface is deeper and along gradient zones marking abrupt depth changes. These findings enhance understanding of the complex tectonic evolution of the SCB and provide valuable constraints for predicting potential hydrocarbon locations in this tectonically active and data-scarce region.
- MakaleAçık Erişim2024Scopus SJRQ1A general class of improved population variance estimators under non-sampling errors using calibrated weights in stratified sampling
Pandey, M.K.; Singh, G.N.; Zaman, Tolga; Mutairi, Aned Al; Mustafa, Manahil SidAhmed
This paper proposes a new calibration estimator for population variance within a stratified two-phase sampling design. It takes into account random non-response and measurement errors, specifically applying this method to estimate the variance in Gas turbine exhaust pressure data. The study integrates additional information from two highly positively correlated auxiliary variables to develop a general class of estimators tailored for the stratified two-phase sampling scheme. The properties of these estimators, in terms of their biases and mean square errors, have been thoroughly examined and extensively analyzed through numerical and simulation studies. Furthermore, the calibrated weights of the strata are derived. The proposed estimators outperform the natural estimator of population variance. Finally, suitable recommendations have been made for survey statisticians intending to apply these findings to real-life problems.
AtıfScopus23WoS16OpenAlex23İncele - MakaleYalnız künye2004Scopus SJRQ3The morphology and chemistry of K-feldspar megacrysts from Ikizdere Pluton: Evidence for acid and basic magma interactions in granitoid rocks, NE-Turkey
Karsli, O.; Aydin, F.; Sadiklar, M.B.
Ikizdere Pluton consists of granite, granodiorite, tonalite, monzonite, quartz monzonite containing pinkish colored K-feldspar megacrysts (KFMs). The crystal sizes of the KFMs range from 1 to 4 cm. The lath-shaped megacrysts are uniformly (i.e., randomly) distributed in the host plutonic rocks and have mafic and felsic inclusions whose crystal sizes are smaller than 1 mm. The crystal inclusions are biotite, slightly annitic in composition with XMg[=Fetot/(Fetot+Mg)]=0.50-0.58, amphibole (magnesio-hornblende, XMg[=Mg/(Mg+Fetot) ]=0.70-0.79), iron-titanium oxide (low titanium magnetit and ilmenite), plagioclase (Ab75-25An65-35) and as minor quartz. The compositions of the KFMs range from Or95Ab5An0 to Or82Ab17An1. BaO contents of the megacrysts increase from core to rim. The mafic and felsic inclusions are compositionally similar those of the host rocks. The chemical and textural features of K-feldspar are typical for megacrysts that grew as phenocrysts in dynamic granitoidic magma systems. The overgrowth of KFMs and mafic magma injections (magma mixing) may be related to temperature, pressure and compositional fluctuations in the magma chamber. Remnant of earlier formed K-feldspar crystals remain in the felsic magma system, while the mafic injection can decompose some earlier precipitated KFMs. The remnant of K-feldspar remaining after mafic injection are overgrown by rapid diffusion of Ba, K and Na elements in liquid phase, during the later stages of crystallization of the host magma.
AtıfScopus25OpenAlex29İncele - MakaleAçık Erişim2024Scopus SJRQ1Thenovel numerical solutions for conformable fractional Kuramoto-Sivashinsky equations by using Cq-HATM and CHPETM
Avit, Özkan; Anac, Halil
The present study used the novel conformable fractional methods to examine the nonlinear Kuramoto-Sivashinsky equations of the conformable fractional derivative. The Kuramoto-Sivashinsky equation is a mathematical model employed to elucidate a diverse range of chemical and physical phenomena, encompassing chemical reaction-diffusion processes, plasma instabilities, viscous flow issues, flame front propagation, and magnetized plasmas. The present inquiry provides an examination of convergence and error for the future scheme. The conformable q-homotopy analysis transform method (Cq-HATM) provides h-curves that illustrate the convergence range of the series solution achieved. In order to validate the effectiveness and suitability of the Cq-HATM, we examine separate instances. In this study, we introduce an application that demonstrates the potential benefits and effectiveness of the proposed approach. Furthermore, an error analysis is performed in order to verify the accuracy of the scheme. Numerical simulations are conducted to validate the precision of the forthcoming approach. The findings obtained from the numerical and graphical analyses are presented in this study. The method provided in this study showcases a notable degree of computational precision and ease in examining and resolving intricate phenomena related to conformable fractional nonlinear partial differential equations within the domains of science and technology.
AtıfScopus5WoS4OpenAlex5İncele - MakaleAçık Erişim2024Scopus SJRQ1Fusion of transformer attention and CNN features for skin cancer detection
Reis, Hatice Catal; Turk, Veysel
Melanoma is a skin cancer that spreads quickly and has serious risks. Early diagnosis is essential, but since the symptoms of skin lesions in the early stages are vague and similar, they can be difficult for specialists to detect. Therefore, machine learning-based alternative diagnostic methods can be developed in addition to existing ones. This study proposes a new deep learning model, a modified lightweight vision transformer (ViT) architecture, and a hybrid framework developed with an integrated deep learning model and an Ensemble Learning (EL) model for the early-stage diagnosis of skin lesions. The proposed deep learning model was developed based on convolution layers and transformers. The model is called multi-head attention block depthwise separable convolution network (MABSCNET). The proposed hybrid framework was developed by combining modern deep learning and EL models pre-trained with the ImageNet dataset along with the MABSCNET model. In the experimental process, the effectiveness of the proposed methods was evaluated on the ISIC 2020 dataset. Additionally, additional experiments were conducted on ISIC 2018 and a Kaggle dataset to analyze the proposed hybrid framework's classification performance. Image enhancement techniques were used in the datasets. In the ISIC 2020 dataset, the MABSCNET model reached 78.63 % accuracy, the ViT model obtained 76.50 %, and the hybrid framework reached 92.74 % accuracy. Moreover, the proposed hybrid framework achieved 100 % on the ISIC 2018 dataset and 94.24 % on the Kaggle dataset.
AtıfScopus62WoS37OpenAlex51İncele
