Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(67)
- Merdan, Mehmet(59)
- Duran, Celal(49)
- Ozdes, Duygu(46)
- Kaygusuz, Abdullah(45)
- Demir, Selim(37)
- Turan, Ibrahim(37)
- Karsli, Orhan(36)
- Öztürk, Serkan(35)
- Dokuz, Abdurrahman(34)
- Araz, Onur(32)
- Kandemir, Raif(31)
- Kulakaç, Nurşen(29)
- Sipahi, Ferkan(29)
- Arslan, Mehmet(27)
- Baltaci, Cemalettin(27)
- Baltacı, Cemalettin(27)
- Kurt, Kemal(27)
- Topal, Fevzi(27)
- Gücer, Mehmet Ali(25)
- Peker, Iskender(25)
- Aydin, Faruk(24)
- Bayrakdaroglu, Serdar(24)
- Maden, Nafiz(24)
- Ozturk, Samet(24)
- Vural, Alaaddin(24)
- Yolcu, Halil(24)
- Yücel, Cem(24)
- Aliyazicioglu, Yuksel(23)
- Kankal, Murat(23)
- Reis, Hatice Catal(23)
- Ürkek, Bayram(23)
- Günen, Mehmet Akif(22)
- Kurnaz, Muammer(22)
- Topal, Meryem(22)
- Karimullah, Suud Sarim(21)
- Uysal, Ibrahim(21)
- Ashyralyyev, Charyyar(20)
- Aydin, Aydanur(20)
- Bayraktar, Alemdar(20)
Yayınlar
- DüzeltmeAçık Erişim2022Scopus SJRQ3Correction to: The First Measurement for Mass Attenuation Coefficients, Effective Atomic Numbers, and Electron Densities of Y123 and Y358 High-Temperature Superconductors (HTS) for the Energies from 46.6 to 1332 keV (Journal of Superconductivity and Novel Magnetism, (2021), 34, 3, (695-703), 10.1007/s10948-020-05771-0)
Düzgün, İbrahim
The original version of this article contained a mistake. Thus this erratum is presented to fix this error. The section “Funding” should read as follows: This study was funded by the Grant-in-Aid for Gümüşhane University Research Fund (GÜBAP), from the Gümüşhane University (Project Number: 13.F5120.02.1).
- MakaleAçık Erişim2022Conformable Fractional Elzaki Decomposition Method of Conformable Fractional Space-Time Fractional Telegraph Equations
Anaç, Halil
Conformable space-time fractional linear telegraph equations are examined using a new method known as conformable fractional Elzaki decomposition method. The suggested method combines the Adomian decomposition method with the conformable fractional Elzaki transform. It is found that numerical simulations confirm the effectiveness and reliability of the proposed method.
AtıfScopus5OpenAlex9
İncele - MakaleYalnız künye2022Scopus SJRQ1Major tectonic features and geodynamic setting of the Black Sea Basin: Evidence from satellite-derived gravity, heat flow, and seismological data
Maden, Nafiz; Elmas, Ali
The origin and development of the Black Sea Basin (BSB) remain controversial. In this study, we determined the main tectonic features of the BSB using satellite gravity, heat flow, and seismological data. Positive gravity anomalies are observed in the arc region due to high-density material, while negative gravity anomalies are seen in the trench region owing to the mass deficiency and sediments. The trench region has a relatively low heat flow anomalies along the Black Sea coasts. The Moho depth increases from 18.11 km in the Eastern Black Sea Basin (EBSB) to 51.83 km in the Eastern Anatolia Plateau (EAP) with an average of 34.13 ± 6.15 km. The lithosphere thickness changed between 78.48 km beneath Anatolia and 120.57 km below the EBSB with an average of 99.17 ± 8.17 km. The low heat flow and Moho temperature values indicate that the lithosphere is strong and cold beneath the BSB. The numerical results, therefore, provide evidence for southward subduction of the Tethys oceanic lithosphere below the Anatolian plate during the late Mesozoic-Cenozoic. Considering all geophysical and geological data, we conclude that the Black Sea Basin represents a relict basin, rather than a back-arc basin.
AtıfScopus16WoS16OpenAlex14
İncele - MakaleYalnız künye2022Scopus SJRQ2Economic Integration, Spatial Interaction and Labour Income Share: Evidence from the EU-13 Countries and the UK
Çelik, Orkun; Karadağ, Metin
We aim to investigate the effect of Single Market Programme on the spatial interaction of labour income share amongst the EU countries. Spatial panel data analysis is used for the aim of the study. The dataset is obtained from AMECO and WDI databases and covers the time period of 1960–2017. The results show that sign of spatial interaction between these countries in term of the labour income share has turned from positive to negative after the Single Market Programme. In other words, the Single Market Programme has induced to decrease the labour income share by negatively affecting the spatial interaction between these countries. In addition, we find that although the negative impacts of capital-output ratio and trade openness on the labour income share decrease, the negative impact of total factor productivity increases after the Single Market Programme. The results of robustness check also confirm our empirical findings.
AtıfWoS1OpenAlex3İncele - MakaleYalnız künye2022Scopus SJRQ1A multi-stage decision making model for determining a suitable innovation structure using an open innovation approach
Yildirim, Ercan; AR, Ilker Murat; Dabić, Marina; Baki, Birdogan; Peker, Iskender
This study seeks to form an end-to-end analysis of Open Innovation stages, developing a three-part consecutive multi-stage decision making model for a suitable innovation structure by linking the processes used to determine the innovation type (open, closed), the OI type (inbound, outbound, coupled), and the collaboration type (science-based, market-based). The decision-making criteria for the OI stage are determined by academic literature and finalized by Delphi technique. The criteria for relationships are determined through expert evaluation. The Fuzzy Analytic Network Process is applied in order to determine the weights and rankings. The most important criterion to consider when choosing the innovation type is open innovation awareness. For the OI type, the most important criterion is knowledge acquisition and, for collaboration, it is network building. This approach allows us to predict the potential risks or costs of the OI process and the possibility of decision errors can thus be reduced.
AtıfScopus24WoS16OpenAlex21İncele - MakaleYalnız künye2022Scopus SJRQ2Effect of Working Conditions on the Lubricated Wear Behavior of Zn-40Al-2Cu-2Si Alloy in the As- Cast and T6 Heat-Treated States
Savaskan, Temel; Hekimoglu, Ali Pasa; Azakli, Zeki; Calis, Merve
In order to determine the effect of working conditions on the lubricated wear behavior of Zn-40Al-2Cu-2Si alloy in the as-cast and T6 heat-treated states, its tribological properties were studied at different oil flowrates, contact pressures, and sliding speeds in comparison with SAE 660 bronze. It was observed that the friction coefficient, temperature, and wear volume of both materials decrease, but their average surface roughness increase with increasing oil flowrate. As the pressure increased, the friction coefficient and average surface roughness of the experimental materials decreased, but their temperature and wear volume increased. It was also found that the working temperature of these materials increased, but their wear volume showed a decrement and a subsequent increment with increasing sliding speed. In addition, their wear volume and average surface roughness showed opposite changes with the sliding speed. Zn-40Al-2Cu-2Si alloy in both as-cast and heat-treated conditions showed lower wear volume and friction coefficient than SAE 660 bronze. This indicates that Zn-40Al-2Cu-2Si alloy can be used to manufacture diesel engine crankshaft journal bearings.
AtıfScopus8WoS8OpenAlex10İncele - MakaleYalnız künye2022Scopus SJRQ2In vitro and in silico evaluation of some plant extracts and phytocompounds against multidrug-resistant Gram-negative bacteria
Aydemir, Eda; Sarıyer, Emrah; Akyıldız, Esma; Özad Düzgün, Azer; Camadan, Yasemin; Saral Sarıyer, Ayşegül
The spread of multidrug-resistant Gram-negative (MDR) bacteria is a global public health problem, as infections caused by MDR Gram-negative bacteria are difficult to treat. New antibiotic agents need to be developed to overcome this problem, and phytochemicals show promise at this point. In this study, methanol extracts were prepared from cinnamon, thyme, nettle, white tea, rosehip, and antibacterial activity of the methanol extracts was studied against two MDR Gram-Negative bacteria (K. pneumoniae and A. baumannii) by broth microdilution method. The MICs of methanol extracts of cinnamon, rosehip, thyme, white tea for A. baumannii were found as 0.015125 g/ml, 0.07825 g/ml, 0.030625 g/ml, 0.00796875 g/ml, respectively. It was found that only cinnamon methanol extract had antibacterial activity in the used extract concentrations against K. pneumoniae and the MIC value was 0.0605 g/ml. The effects of plant methanol extract with antibacterial activity and imipenem combinations were studied in vitro using the checkerboard method. The FIC Indexes were obtained from the checkerboard results and it was observed that the combination of methanol extract and imipenem showed an antagonistic or additive/indifferent effect but not a synergistic effect. We evaluated the binding affinity of epigallocatechin 3-gallate, quercetin, cinnamaldehyde, carvacrol, and thymol phytocompounds using in silico methods, which are well known as a phytocompounds in white tea, cinnamon, thyme, nettle, and rosehip and have antibacterial activities. The results suggested that these phytocompounds should be supported with in vivo and in vitro experiments to investigate their potential for being inhibitor candidates.
AtıfScopus6WoS4OpenAlex6İncele - MakaleAçık Erişim2022Scopus SJRQ1Finite-Time Neuro-Sliding-Mode Controller Design for Quadrotor UAVs Carrying Suspended Payload
Bingöl, Özhan; Güzey, Hacı Mehmet
Due to the quadrotor’s underactuated nature, suspended payload dynamics, parametric uncertainties, and external disturbances, designing a controller for tracking the desired trajectories for a quadrotor that carries a suspended payload is a challenging task. Furthermore, one of the most significant disadvantages of designing a controller for nonlinear systems is the infinite-time convergence to the desired trajectory. In this paper, a finite-time neuro-sliding mode controller (FTNSMC) for a quadrotor with a suspended payload that is subject to parametric uncertainties and external disturbances is designed. By constructing a finite-time sliding mode controller, the quadrotor can follow the reference trajectories in finite time. Furthermore, despite time-varying nonlinear dynamics, parametric uncertainties, and external disturbances, a neural network structure is added to the controller to effectively reduce chattering phenomena caused by high switching gains, and significantly reduce the size of the control signals. Following the completion of the controller design, the system’s stability is demonstrated using the Lyapunov stability criterion. Extensive numerical simulations with various scenarios are run to demonstrate the effectiveness of the proposed controller.
AtıfScopus28WoS22OpenAlex21İncele - MakaleAçık Erişim2022Scopus SJRQ1Innovative approaches to the trend assessment of streamflows in the Eastern Black Sea basin, Turkey
Akçay, Fatma; Kankal, Murat; Şan, Murat
The issue of detection of hydrometeorological trends remains relevant because of the importance of climate change in design, operation, and management studies related to water resources. This study examines the effects of changes in climate and land use on monthly flows (1962–2018) in the Eastern Black Sea basin, Turkey, using innovative trend analysis methods. In this context, innovative polygon trend analysis (IPTA) and innovative trend significance test (ITST) were used to detect the trends and compared with Mann-Kendall test. Only stations with homogeneous data that did not experience non-climatic changes are used in the analysis. IPTA and ITST approaches are much more sensitive than Mann-Kendall in detecting trends. Although the innovative methods are mostly compatible with each other (90%), IPTA presents additional information about trend transitions between successive parts of time series. Results indicate significant decreasing trends in summer months, likely due to diminishing precipitation and effective evaporation.
AtıfScopus48WoS46OpenAlex56İncele - MakaleYalnız künye2022Scopus SJRQ2Proportional control moment gyroscope for two-wheeled self-balancing robot
Ünker, Faruk
A two-wheeled self-balancing robot is considered for investigating the responses of a control moment gyroscope powered by a proportional controller to prevent the robot rollover against the constant inertia forces because of accelerations of the wheels of the robot. The amplitudes of the frequency equations related to the required angular momentum of flywheels with an optimum controller gain were also found. A simulation model of the robot using computer-aided engineering software (RecurDyn) is built to verify the equations of a Lagrangian model. The results of both obtained from the Lagrangian and that from RecurDyn simulations are analyzed comparatively, in which the proportional control loop reduces the required flywheel speeds Ω of gyros and keeps the robot in a very small amplitude of a stable sinusoidal motion in the upright position.
AtıfScopus23WoS12İncele - MakaleAçık Erişim2022Scopus SJRQ2A new cryptic species of the Darevskia parvula group from NE Anatolia (Squamata, Lacertidae)
Arribas, Oscar; Candan, Kamil; Kurnaz, Muammer; Kumlutaş, Yusuf; Caynak, Elif Yıldırım; Ilgaz, Çetin
In this study, we re-examine the Darevskia parvula group comprehensively using morphology, osteology and mitochondrial phylogeny, and describe a new endemic species from Turkey: Darevskia tuniyevisp. nov. A total of 257 adult specimens were evaluated for external morphology (scalation and biometry) with univariate (descriptive statistics and ANOVA with post-hoc tests) and multivariate (Discriminant Analysis and ANOSIM) analyses. In parallel, osteological data and molecular analyses using three DNA markers (mitochondrial 16S rRNA and Cyt-b, nuclear Rag-1) were used to complete the description of the new taxon. The molecular phylogenetic analyses indicated that the D. parvula group is composed of three taxa as D. parvula, D. adjarica and D. tuniyevisp. nov., and showed that D. adjarica and D. tuniyevisp. nov. are reciprocal sister taxa. On the other hand, D. adjarica is morphologically very different from other two forms, while D. parvula is hardly distinguishable externally from D. tuniyevisp. nov. Therefore, we can consider that D. parvula and D. tuniyevisp. nov. are cryptic species. These two cryptic species retain their primitive morphology within the group, while D. adjarica has changed, perhaps due to different bioclimatic conditions in its Pleistocene refuge and current area.
AtıfScopus14WoS11OpenAlex11İncele - MakaleYalnız künye2022Scopus SJRQ2InSiNet: a deep convolutional approach to skin cancer detection and segmentation
Reis, Hatice Catal; Turk, Veysel; Khoshelham, Kourosh; Kaya, Serhat
Cancer is among the common causes of death around the world. Skin cancer is one of the most lethal types of cancer. Early diagnosis and treatment are vital in skin cancer. In addition to traditional methods, method such as deep learning is frequently used to diagnose and classify the disease. Expert experience plays a major role in diagnosing skin cancer. Therefore, for more reliable results in the diagnosis of skin lesions, deep learning algorithms can help in the correct diagnosis. In this study, we propose InSiNet, a deep learning-based convolutional neural network to detect benign and malignant lesions. The performance of the method is tested on International Skin Imaging Collaboration HAM10000 images (ISIC 2018), ISIC 2019, and ISIC 2020, under the same conditions. The computation time and accuracy comparison analysis was performed between the proposed algorithm and other machine learning techniques (GoogleNet, DenseNet-201, ResNet152V2, EfficientNetB0, RBF-support vector machine, logistic regression, and random forest). The results show that the developed InSiNet architecture outperforms the other methods achieving an accuracy of 94.59%, 91.89%, and 90.54% in ISIC 2018, 2019, and 2020 datasets, respectively. Since the deep learning algorithms eliminate the human factor during diagnosis, they can give reliable results in addition to traditional methods. Graphical abstract: [Figure not available: see fulltext.]
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İncele - MakaleYalnız künye2022Scopus SJRQ3The Effect of Surface Morphology of Silver Nanoparticles on the Selectivity of Styrene Epoxidation
Sarlblylk, Oǧuz Yunus
Catalytic materials at the nanoscale level have an enormous impact on sustainable environmental protection, which is important for the future. Therefore, the researchers will intensively carry out the design of catalytic materials with well-ordered surface structures. In more detail, morphology-controlled nanoparticles have special interactions with the reactants that increase catalytic performance and influence the selectivity for catalytic reactions. For those reasons, obtaining specifically surface structure-tuned nanocrystals having different surface arrangements is a significant priority that promises the best model relationship between well-oriented surface structure and catalytic performance. In this study, silver nanocrystals shaped with cubes, truncated octahedrons, and octahedrons were produced. Their catalytic behaviors were examined as an innovation for epoxidation/oxidation reactions of styrene in mild conditions. The morphological and surface characterizations of nanocrystals were determined by analytical and instrumental methods such as high-resolution transmission electron microscopy energy dispersive X-ray (HR-TEM-EDX), X-ray diffraction (XRD), as well as inductively coupled plasma mass spectroscopy optical emission spectrometry (ICP-OES), and gas chromatography-mass spectrometry (GC-MS). According to the results, nanoparticles having different surface-facets fractions can be employed to increase the selectivity of styrene epoxide.
AtıfScopus3WoS3OpenAlex3İncele - MakaleYayıncıda açık erişim2022Scopus SJRQ3Information theory and machine learning based authentication of flaxseed oil using portable and handheld vibrational spectroscopy sensors
Aykas, Didem-Peren; Menevseoglu, Ahmed; Gunes, Nurhan
Flaxseed oil is one of the popular edible oils, and its adulteration has become a concern because of its high commodity value. Therefore, there is a need to detect adulterated flaxseeds with a rapid, non-invasive, and simple method to keep the quality of flaxseed oil. This study aimed to develop a machine learning algorithm and information theory to detect adulterated flaxseed oils by vibrational spectroscopy units combined with chemometrics. Oil spectra were collected with portable/handheld vibrational spectroscopic units and analyzed using conditional entropy, support vector machines (SVM), and soft independent modeling of class analogy (SIMCA) to generate classification models to identify the pureness of oils and partial least square regression (PLSR) to predict the adulterant levels and fatty acid distributions. Conditional entropy showed that two or three wavenumbers/shifts could discriminate the oils using machine learning algorithms with an accuracy of over 95%. SIMCA models determined the oils with an interclass distance (ICD) over 1.1. Specifically, the Fourier transform mid-infrared (FT-MIR) unit provided the best classification of the oils with ICD over 4.9. All instruments showed good performance in predicting fatty acids and adulteration levels with rval≥0.89 and standard error prediction (SEP) ≤1.7%. Overall, these portable/handheld units showed great potential for rapid, simple, and non-invasive monitoring to identify adulterated flaxseed oils.
AtıfScopus7WoS7OpenAlex7İncele - MakaleAçık Erişim2022Scopus SJRQ3Phytoremediation ability of Helichrysum arenarium plant for Au and Ag: case study at Demirören village (Gümüşhane, Turkey)
Vural, Alaaddin; Safari, Semaneh
It was investigated ability of Helichrysum arenarium plant, in phytoextraction, phytostabilization, and phytoremediation in this study. Soil and plant samples were collected from the Demirören alteration site which has the potential of gold mineralization and analyzed for gold and silver. When the results of the analysis were evaluated, it was determined that the gold and silver contents in the soil did not show compatibility with the gold and silver contents of the plants grown at the same point. It was concluded that the high gold and silver concentrations in the plants are related to the hydrothermal alteration and weathering at the point where the plants grow. For investigation of phytoremediation ability of the plant, translocation factor (TF), bio-concentration factor (BCF), and bioaccumulation factor (BAF) were calculated. The values of TF, BAF, and BCF for Ag are equal 0.33, 0.043, and 0.13 and for Au are equal 2.04, 0.59, and 0.29, respectively. So, obtained data show that Helichrysum arenarium is not appropriate for phytoextraction and phytostabilization of gold and silver in this case, but H. arenarium can be used in phyto-mining and for biogeochemical exploration of gold. Considering that the gold and silver concentrations in the developed soil in the study area are low concentrations, it is predicted that a similar study will yield satisfactory-interesting results when it is made in plants grown on the gold mineralization/enrichment areas.
AtıfScopus9WoS9OpenAlex11İncele - MakaleYalnız künye2022Scopus SJRQ3Roza: a new and comprehensive metric for evaluating classification systems
Melek, Mesut; Melek, Negin
Many metrics such as accuracy rate (ACC), area under curve (AUC), Jaccard index (JI), and Cohen’s kappa coefficient are available to measure the success of the system in pattern recognition and machine/deep learning systems. However, the superiority of one system to one other cannot be determined based on the mentioned metrics. This is because such a system can be successful using one metric, but not the other ones. Moreover, such metrics are insufficient when the number of samples in the classes is unequal (imbalanced data). In this case, naturally, by using these metrics, a sensible comparison cannot be made between two given systems. In the present study, the comprehensive, fair, and accurate Roza (Roza means rose in Persian. When different permutations of the metrics used are superimposed in a polygon format, it looks like a flower, so we named it Roza.) metric is introduced for evaluating classification systems. This metric, which facilitates the comparison of systems, expresses the summary of many metrics with a single value. To verify the stability and validity of the metric and to conduct a comprehensive, fair, and accurate comparison between the systems, the Roza metric of the systems tested under the same conditions are calculated and comparisons are made. For this, systems tested with three different strategies on three different datasets are considered. The results show that the performance of the system can be summarized by a single value and the Roza metric can be used in all systems that include classification processes, as a powerful metric.
AtıfScopus7WoS8OpenAlex9İncele - MakaleYalnız künye2022Scopus SJRQ1Optimization of multiple tuned mass dampers for a two-span continuous railway bridge via differential evolution algorithm
Araz, Onur; Kahya, Volkan
The study aims at proposing a methodology for optimization of multiple tuned mass dampers (MTMD) in reducing the multi-resonance vibrations of continuous bridges due to moving train loads. The equations of motion for time-domain analysis are derived for obtaining train-induced vibrations of a two-span continuous railway bridge with equipped MTMD-1 and MTMD-2 devices when the vehicle-bridge interaction (VBI) is considered. The bridge and the train are modeled as a Bernoulli-Euler beam with constant section and a series of moving sprung masses of identical length, respectively. To reduce the multiple resonance vibrations of a two-span continuous railway bridge, the MTMD-1 and MTMD-2 are tuned to the first mode and the second mode of the bridge, and they are attached to the midspan of each span, respectively. The optimum parameters of the both MTMD systems are investigated using the differential evolution (DE) method. The criterion chosen to obtain the optimum parameters is the minimization of the first two resonance peaks of the bridge. The influence of the different mass ratios and the number of TMD units in the MTMD system on the optimum parameters of the both MTMD systems and corresponding displacement responses of the bridge are also investigated. The results show that the VBI effect does not have much effect on the resonant train speeds and the control performance of TMDs. Therefore, the optimum parameters of TMDs can be obtained quickly by modeling the train as a series of moving forces for the vibration control of railway bridges.
AtıfScopus33WoS32OpenAlex33İncele - MakaleYalnız künye2022Scopus SJRQ1Robust copy-move detection in digital audio forensics based on pitch and modified discrete cosine transform
Ustubioglu, Beste; Küçükuğurlu, Büşranur; Ulutas, Guzin
Copy-move forgery is one of the most widely used methods in the field of audio forensic because it is difficult to detect and convenient to apply. However, post-processing operations applied to forged speech to hide traces of forgery make detection of forensic more difficult. In this study, we propose a robust method for detection and localization of the audio copy-move forgery using modified discrete cosine transform (MDCT). For this purpose, we first divide the speech recording into voiced and unvoiced parts by extracting a pitch sequence from the speech recording. After the determination of voiced parts, we extract MDCT coefficients from them and take the mean of the transpose of the coefficient matrix as the feature. These MDCT features are very robust against commonly used post-processing operations (especially audio compressing). Euclidean distance (ED) is applied to compute the similarities between the features. The voiced parts, which give minimum ED are determined as copy-move audio parts. Also, two separate databases (Pitch-based and Voice Activity Detection (VAD-based) are created during the work to evaluate the performance of the proposed method because there is no common database in the field of audio forensic in the literature. Experiment results show that the proposed method gives better results for detection and localization of audio copy-move forgery on different databases compared to other studies in the literature. The proposed method is also robust against common post-processing operations such as noise addition, filtering operation, and especially compression operation.
AtıfScopus22WoS17OpenAlex23İncele - MakaleAçık Erişim2022Scopus SJRQ1Zircon U[sbnd]Pb geochronology and petrology of the tholeiitic gabbro from the Kovanlık (Giresun) area: Constraints for the Late Cretaceous bimodal arc magmatism in the Eastern Pontides Orogenic Belt, NE Turkey
Temizel, İrfan; Arslan, Mehmet; Abdioğlu Yazar, Emel; Aslan, Zafer; Kaygusuz, Abdullah; Baki Eraydın, Tuğba
Mafic intrusions of the Eastern Pontides Orogenic Belt (EPOB) in NE Turkey are found rarely in varying ages, sizes and compositions. Of these, tholeiitic gabbro stocks, namely Kovanlık gabbro, consist of pyroxene gabbro and minor hornblende gabbro with a mainly granular texture. The pyroxene gabbro contains plagioclase, clino- and ortho-pyroxene, olivine, and Fe[sbnd]Ti oxides, whereas the hornblende gabbro includes mainly plagioclase, hornblende, rarely biotite and Fe[sbnd]Ti oxides. The clinopyroxene compositions of the pyroxene gabbro exhibit arc-related tholeiitic magmas. The Kovanlık gabbroic rocks have high U/Yb zircon ratios, implying continental arc-related tectonic settings. Zircon U[sbnd]Pb dating on the Kovanlık gabbro yielded a concordia age of ~92 Ma (Turonian). Petrochemically, the gabbroic rocks have a tholeiitic character and show arc- and MORB-like signatures. The gabbroic rocks show positive Rb, Ba, K, Pb, Sr, Ti and negative Nb, Ce, Nd, Hf, Zr anomalies in N-MORB normalized diagrams. The chondrite-normalized REE plots of the rocks show flat to feeble right-dipping REE patterns (LaN/LuN = 0.94–2.56) with positive Eu anomalies (EuN/Eu* = 1.15–2.14; except for two pyroxene gabbro samples). The gabbroic rocks have 87Sr/86Sr(i) ratios (0.704533 to 0.706265), εNd(i) values (4.04–4.85), 206Pb/204Pb (18.56–18.68) and 207Pb/204Pb (15.61–15.64) ratios. Low Nb/La and Nb/Y ratios, as well as high Sr/Yb and Ba/Rb ratios, indicate that source regions were modified by slab-derived fluids and/or melts. The obtained zircon dating, isotopic and geochemical data, as well as regional geology, revealed that the tholeiitic mafic magma derived from a spinel-lherzolite mantle at a relatively shallow depth, and the Kovanlık gabbro in the EPOB represents one of the first mafic intrusions of Late Cretaceous bimodal arc magmatism related to the roll-back of the northwards subducting Tethys oceanic plate.
AtıfScopus19WoS17OpenAlex20İncele - MakaleYalnız künye2022Scopus SJRQ1A decision support tool for the student–supervisor allocation problem of postgraduate programs
Bahadır Şimşek, Ahmet
The stable supervisor-student allocation (SSA) is crucial in the success of the research at the postgraduate education. The difference of SSA from the well-known student-project allocation (SPA) problem is that it moves the determination of the research topic to after the allocation, thus allowing the student and the lecturer to discuss the research topic. In the education systems of developing countries where decision support systems are not prevalent, the student–lecturer allocation is performed manually with a greedy approach, which can result in unstable matches. In this study, we propose a multi-objective binary model that allows decision-makers to shift between three main allocation strategies with a trade-off parameter. We test the model with a real dataset of a postgraduate program in Turkey. Experiments show that the model can successfully implement different strategies, and there can also be more than one breaking point between strategies. Also, we transform the model into a decision support tool that provides easy use to the decision-maker and reports the solutions of the trade-off parameter sensitivity analysis. The tool reports the level of satisfaction for each strategy at different breakpoints, allowing the decision-maker to see its options.
AtıfScopus6WoS3OpenAlex5İncele