Advanced Lake Shoreline Extraction Approach by Integration of SAR Image and LIDAR Data     

Nusret Demir  Bülent Bayram  Dursun Zafer Şeker  Selen Oy  Abdülkadir İnce  Salih Bozkurt 《Marine Geodesy》2019,42(2):166-185

Noise and an abnormal distributed-image histogram is the main challenge of using SAR data. From this point of view, this study’s authors motivated the non-use of user-defined input parameters. To achieve this purpose, a fuzzy approach was proposed to extract shoreline from SENTINEL-1A data. The parameters in the processing of the SENTINEL-1A image were generated automatically with LIDAR-intensity-derived object-based segmentation results. The LIDAR-intensity image was segmented with the Mean-shift method. The corresponding result was used to estimate the input parameters for fuzzy clustering of the SENTINEL-1A image. Fuzzy segmentation was proposed, due to the expected large number of values regarding water and land classes except for the pixels along the shoreline. The memberships for land and water classes were separately computed. In the proposed approach, the results from LIDAR and SENTINEL-1A dataset are promising, with differences below 1 pixel (10?m) by evaluation with the used reference vector data.  相似文献   

Petrogenesis of post-collisional Middle Eocene volcanism in the Eastern Pontides (NE,Turkey): Insights from geochemistry,whole-rock Sr-Nd-Pb isotopes,zircon U-Pb and 40Ar-39Ar geochronology     

Emre Aydınçakır  Cem Yücel  Gilles Ruffet  Mehmet Ali Gücer  Enver Akaryalı  Abdullah Kaygusuz 《Chemie der Erde / Geochemistry》2022,82(2):125871

The debate about whether Eocene magmatism is considered to be post-collisional or subduction-related or not still continues. Here we offer new ⁴⁰Ar-³⁹Ar ad U-Pb zircon geochronology, mineral chemistry, bulk rock and Sr-Nd-Pb isotope geochemistry data obtained from the southern dike (SD) suite, in comparison with the northern dike (ND) suite, from the Eastern Pontides. The geochronological data indicate that the SD suite erupted between 45.89 and 45.10 Ma corresponding to the Lutetian (Middle Eocene). The magmas of the ND suite are characterised by slightly more alkaline affinity compared to the SD suite. The trace and rare earth element (REEs) content of the SD suite is characterised by large ion lithophile element (LILEs; Sr, K₂O, Ba, Rb) enrichment and depletion of Nb, Ta, and TiO₂ elements to different degree with high Th/Yb ratios, which indicate that the magmas forming the SD and ND suites were derived from lithospheric mantle sources enriched by mostly slab-derived fluids in the spinel stability field. The Sr, Nd and Pb radiogenic isotope ratios of the dikes support the view that the magma for the hydrous group (H-SD) was derived from a relatively more enriched mantle source than the other SD and ND suites. The ND suite and the anhydrous group (A-SD) display similar geochemical features characterised by moderate light earth element (LREE)/heavy rare earth element (HREE) ratios, while the H-SD group has respectively lower LREE/HREE ratios indicating higher melting degree. Detailed considerations of the alkalinity, enrichment and partial melting degree for the source of the studied volcanic rocks indicate that the magmas of the northern dike suite are characterised by slightly more alkaline affinity, whereas the magmas throughout the southern dike suite show increments in the enrichment rate and melting degree. In light of the obtained data and comparative interpretations, the geodynamic evolution and differences in petrogenetic character of the Lutetian magmas from both the northern and southern parts of the Eastern Pontides may be explained by different degrees of melting of a net veined mantle source initially metasomatized by mostly subduction fluids during asthenospheric upwelling due to fragmented asymmetric delamination in a post-collisional extensional tectonic environment.  相似文献   

Inferring network paths from point observations     

Timothy C. Matisziw  Emre Demir 《International journal of geographical information science》2013,27(10):1979-1996

The use of geographically referenced point data, such as that obtained from global positioning systems (GPS), is rapidly increasing. However, due to error and uncertainty inherent in most geographic datasets, the ability to accurately associate these point locations with other layers of geographic data is still a challenge. One difficulty in particular is how to associate spatially and temporally referenced point-based observations of a network activity with a network topology such that a continuous network path can be best inferred. In this article, an optimization method for inferring a network path from a temporal sequence of point observations of location is presented. An application to GPS data is provided to highlight various characteristics of the proposed modeling approach relative to several other available techniques.  相似文献   

The impact of mergers on relaxed X-ray clusters – I. Dynamical evolution and emergent transient structures     

Gregory B. Poole  Mark A. Fardal  Arif Babul  Ian G. McCarthy  Thomas Quinn  James Wadsley 《Monthly notices of the Royal Astronomical Society》2006,373(3):881-905

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The evolution of substructure in galaxy, group and cluster haloes – I. Basic dynamics     

James E. Taylor  Arif Babul † 《Monthly notices of the Royal Astronomical Society》2004,348(3):811-830

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The Effects of Operational Parameters on a Mono-wire Cutting System: Efficiency in Marble Processing     

Emre Yilmazkaya  Yilmaz Ozcelik 《Rock Mechanics and Rock Engineering》2016,49(2):523-539

Mono-wire block cutting machines that cut with a diamond wire can be used for squaring natural stone blocks and the slab-cutting process. The efficient use of these machines reduces operating costs by ensuring less diamond wire wear and longer wire life at high speeds. The high investment costs of these machines will lead to their efficient use and reduce production costs by increasing plant efficiency. Therefore, there is a need to investigate the cutting performance parameters of mono-wire cutting machines in terms of rock properties and operating parameters. This study aims to investigate the effects of the wire rotational speed (peripheral speed) and wire descending speed (cutting speed), which are the operating parameters of a mono-wire cutting machine, on unit wear and unit energy, which are the performance parameters in mono-wire cutting. By using the obtained results, cuttability charts for each natural stone were created on the basis of unit wear and unit energy values, cutting optimizations were performed, and the relationships between some physical and mechanical properties of rocks and the optimum cutting parameters obtained as a result of the optimization were investigated.  相似文献   

Geomorphic evidence for active tectonic deformation in the coastal part of Eastern Black Sea,Eastern Pontides,Turkey     

Mustafa Softa  Tahir Emre  Hasan Sözbilir  Joel Q. G. Spencer  Mehmet Turan 《Geodinamica Acta》2018,30(1):249-264

The Eastern Pontides (EP), which is the under transpressional deformation zone, is an active mountain belt that has been rising rapidly since the Cenozoic era because of the Arabian-Eurasian convergence. Morphometric studies have been performed to investigate the tectonic activity of this region and better understand the characteristics of the faults geomorphologically; the faults control the mountain fronts in the drainage basin of the EP. The results show the Hypsometric Curve (HC)-Hypsometric Integral (0.37-HI-0.67), Basin-Shaped Analysis (1.2-B_s-7), Valley-Floor-Width to Height-Ratio (0.4-V_f-1.2) and Asymmetry Factor (35-AF-81) applied to 46 drainage basins together with 9 tectonically controlled geomorphic indices (1.2-S_mf-1.5) and a Stream Length Gradient (30-S_L-120) indicate that the EP is tectonically active, and when the areas are evaluated according to S_mf and V_f analyses, the tectonic level is relatively high. According to our conceptual model for the uplifting of the EP, with respect to field studies and morphometric analysis, (i) the EP is the active deformation zone and has a “push-up” geometry in conjunction with the North Anatolian Fault; (ii) the EP is progressively uplifting at a rate of more than 0.5 mm/yr in along with the thrust faults of the Black Sea Fault (BSF) and Borjomi-Kazbegi Fault (BKF).  相似文献   

An Extended Approach of Particle Swarm Optimization for Shoreline Extraction from RASAT Imagery     

Hatice Catal Reis  Bülent Bayram  Salih Bozkurt  Abdulkadir Ince  Nusret Demir  Dursun Zafer Seker 《Journal of the Indian Society of Remote Sensing》2018,46(8):1223-1232

This study presents an extended shoreline detection approach from pansharpened images of Turkish RASAT satellite which covers red, green and blue bands of the optical spectrum with 15 m ground resolution and panchromatic band with 7.5 m spatial resolution. The Lake Ercek of Turkey has been selected as the study area, which is a tectonic lake and home to a variety of water birds. The satellite images of the lake taken in 2013 and 2014 were considered for analysis. The proposed shoreline extraction system consists of a sequence of image processing steps in which simple linear clustering (SLIC) and particle swarm optimization (PSO) are the main components. SLIC was used to create superpixels that form basis for object-based image analysis while PSO was employed for classifying objects into corresponding classes. The resulting images still contained unwanted artefacts; therefore, a post-processing step was performed to improve the accuracy of segmentation by applying thresholding, morphological processing, and manual editing for noise removal. The proposed framework was applied on two temporal RASAT images to test the variations of defined parameter settings. The success of the proposed system was to obtain shorelines with satisfying accuracy without using NIR band. Finally, the extracted shorelines were vectorised and compared with manually digitized shorelines from pansharpened satellite images for accuracy assessment.  相似文献   

Accuracy Assessment of Pleiades-1 Stereo/Tri-stereo Digital Surface Models: A Case-Study for Citrus Trees     

Ali Ozgun Ok  Asli Ozdarici-Ok  Emre Baseski 《Journal of the Indian Society of Remote Sensing》2018,46(8):1203-1212

In this study, we assess the quality of the digital surface model (DSM) generated from Pleiades-1 tri-stereo images which can potentially contribute to the detection of citrus trees in terms of height information. The methods tested on stereo/tri-stereo images are; (a) local methods (correlation-based and least squares method), (b) semi-global method (semi-global matching (SGM)), and (c) global method (SIFT-flow). DSMs of three sub-regions of Mersin area have been presented for each stereo/tri-stereo matching method; whereas for the SIFT-flow method, we have only depicted the parallax results. Numerical results reveal that the SGM forward-backward stereo combination which has the largest intersection angle provided the best results in 2 out of 3 test areas. However, the results confirm that none of the methods could reach the desired level of performance for the height estimation of citrus trees that can potentially guide the detection step.  相似文献   

Mineralogy, whole-rock and Sr-Nd isotope geochemistry of mafic microgranular enclaves in Cretaceous Dagbasi granitoids, Eastern Pontides, NE Turkey: Evidence of magma mixing, mingling and chemical equilibration   总被引：7，自引：0，他引：7  

Abdullah Kaygusuz  Emre Ayd?nçak?r 《Chemie der Erde / Geochemistry》2009,69(3):247-277

Rocks of the Late Cretaceous Dagbasi Pluton (88-83 Ma), located in the eastern Pontides, include mafic microgranular enclaves (MMEs) ranging from a few centimetres to metres in size, and from ellipsoidal to ovoid in shape. The MMEs are composed of gabbroic diorite, diorite and tonalite, whereas the felsic host rocks comprise mainly tonalite, granodiorite and monzogranite based on both mineralogical and chemical compositions. MMEs are characterized by a fine-grained, equigranular and hypidiomorphic texture. The common texture of felsic host rocks is equigranular and also reveals some special types of microscopic textures, e.g., oscillatory-zoned plagioclase, poikilitic K-feldspar, small lath-shaped plagioclase in large plagioclase, blade-shaped biotite, acicular apatite, spike zones in plagioclase and spongy-cellular plagioclase textures and rounded plagioclase megacrysts in MMEs. Compositions of plagioclases (An₃₃-An₆₀), hornblendes (Mg#=0.77-1.0) and biotites (Mg#=0.61-0.63) of MMEs are slightly distinct or similar to those of host rocks (An_12-57; hbl Mg#=0.63-1.0; Bi Mg#=0.50-0.69), which suggest partial to complete equilibration during mafic-felsic magma interactions.The felsic host rocks have SiO₂ between 60 and 76 wt% and display low to slightly medium-K tholeiitic to calc-alkaline and peraluminous to slightly metaluminous characteristics. Chondrite-normalized rare-earth element (REE) patterns are fractionated (La_cn/Lu_cn=1.5-7.3) with pronounced negative Eu anomalies (Eu/Eu*=0.46-1.1). Initial ε_Nd(i) values vary between −3.1 and 1.6, initial ⁸⁷Sr/⁸⁶Sr values between 0.7056 and 0.7067.Compared with the host rocks, the MMEs are characterized by relatively high Mg-number of 22-52, low contents of SiO₂ (53-63 wt%), low ASI (0.7-1.1) and low to medium-K tholeiitic to calc-alkaline, metaluminous to peraluminous composition. Chondrite-normalized REE patterns are relatively flat [(La/Yb)_cn=1.4-3.9; (Tb/Yb)_cn=0.9-1.5] and show small negative Eu anomalies (Eu/Eu*=0.63-1.01). Isotope signatures of these rocks (⁸⁷Sr/⁸⁶Sr_(i)=0.7054-0.7055; ε_Nd(i)=-1.0 to 1.9) are largely similar to the host rocks. Gabbroic diorite enclaves have relatively low contents of SiO₂, ASI; high Mg#, CaO, Al₂O₃, TiO₂, P₂O₅, Sr and Nb concentrations compared to dioritic and tonalitic enclaves.The geochemical and isotopic similarities between the MMEs and their host rocks indicate that the enclaves are of mixed origin and are most probably formed by the interaction between the lower crust- and mantle-derived magmas. All the geochemical data suggest that a basic magma derived from an enriched subcontinental lithospheric mantle, interacted with a crustal melt that originated from dehydration melting of the mafic lower crust at deep crustal levels. The existence of compositional and textural disequilibrium and the nature of chemical and isotopic variation in these rock types indicate that magma mixing/mingling between an evolved mafic and a granitic magma was involved in their genesis. Microgranular enclaves are thus interpreted to be globules of a more mafic magma probably from an enriched lithospheric mantle source. Al-in-amphibole estimates the pluton emplacement at ca. 0.3-3.8 kbar, and therefore, magma mixing and mingling must have occurred at 3.8 kbar or below this level.  相似文献