Papers by Çağlayan Balkaya
DOAJ (DOAJ: Directory of Open Access Journals), Dec 1, 2016
Bu çalışmada, parçacık sürü optimizasyonu (PSO), genetik algoritma (GA), farksal evrim (FE) ve ya... more Bu çalışmada, parçacık sürü optimizasyonu (PSO), genetik algoritma (GA), farksal evrim (FE) ve yapay ısıl işlem (YIİ) algoritmalarını kapsayan dört metasezgisel algoritma jeofiziğin bir, iki ve üç boyutlu (1B, 2B ve 3B) ters çözüm problemlerinde kullanılmıştır. Doğal uçlaşma (DU), doğru akım özdirenç (DAÖ), manyetik ve karşılıklı kuyu yer radarı uygulamalarından elde edilen kuramsal ve/veya alan veri kümeleri yukarıda değinilen metasezgisellerden biriyle değerlendirilmiştir. PSO, hem sentetik olarak üretilen hem de Güney Bavyera'da (Almanya) bir grafit yatağında ölçülen DU anomalilerinin model parametrelerinin (elektrik dipol moment, uçlaşma açısı, derinlik, biçim faktörü ve anomali orijini) belirlenmesinde kullanılmıştır. Gerçel değer kodlamalı GA, hem kuramsal hem de Bozdağ, İzmir'de (Türkiye) karstik bir ortamda toplanan düşey elektrik sondajı veri kümelerinden yatay tabakalı yer modelinin parametrelerini (tabaka özdirenç ve kalınlıklarını) kestirmek için kullanılmıştır. Sentetik bir karşılıklı kuyu yer radarı verisinden 2B'lu yeraltı radar hız dağılımının görüntülenmesi amacıyla YIİ ve yuvarlatma kısıtlı doğrusallaştırılmış en küçük kareler yönteminin ardışık kullanılmasına dayanan melez bir yaklaşım uygulanırken; FE algoritması kuramsal olarak üretilen bir toplam alan manyetik anomali haritasının 3B'lu ters çözümünde kullanılmıştır. Her bir metasezgisel algoritmanın gerek duyduğu kullanıcı tanımlı parametreler incelenen problemler dikkate alınarak test çalışmalarıyla belirlenmiştir. Ayrıca, metasezgiseller tarafından elde edilen sonuçların güvenilirlikleri çeşitli istatistiksel ve belirsizlik analizleriyle araştırılmıştır. Burada kullanılan metasezgisellerin çeşitli jeofizik problemlerin model parametrelerinin kestiriminde başarılı sonuçlar üretmesi bu algoritmaların, jeofiziğin küçük ve görece büyük boyutlu veri kümelerine uygulanabilirliğini göstermiştir.
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Scientific Reports, Dec 30, 2022
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Geophysical Journal International
SUMMARY A gravity inversion procedure using the success-history-based adaptive differential evolu... more SUMMARY A gravity inversion procedure using the success-history-based adaptive differential evolution (SHADE) algorithm is presented to reconstruct the 3-D basement relief geometry in sedimentary basins. We introduced exponential population size (number) reduction (EPSR) to reduce the computational cost and used self-adaptive control parameters to solve this highly nonlinear inverse problem. Model parametrization was carried out by discretizing the sedimentary cover via juxtaposed right prisms, each placed below each observation point. Resolvability characteristics of the 3-D inverse problem were revealed through some cost function topography landscapes. The fine-tuned control parameter namely, population number allowed us to get best benefit from the algorithm. Additionally, a stabilizing function as a relative constraint was used to avoid undesired effects originated from the ill-posedness of the problem. In the synthetic data cases, the strategy we propose outperformed the linear...
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Archaeological Prospection, Jul 19, 2018
Pisidian Antioch was founded as a military base in the Hellenistic period around 300 bc. A consec... more Pisidian Antioch was founded as a military base in the Hellenistic period around 300 bc. A consecutive archaeological structure, extending 55 m long, mainly includes two adjacent abscissas and a wall remain thought to be a watchtower. An integrated geophysical survey including ground‐penetrating radar (GPR) and electrical resistivity tomography (ERT) techniques was conducted to determine the existence of counterparts of this structure in a small‐scale area. GPR scans acquired via zigzag mode using 500 MHz antenna along 45 parallel lines were evaluated by a series of basic data processing steps. Considering the results obtained, two‐dimensional (2D) ERT data collected in a restricted area using Wenner‐alpha array along 41 parallel lines were inverted using 2D and three‐dimensional (3D) tomographic inversion schemes. On the basis of the findings obtained from various GPR and ERT imaging techniques, the existence of one of the abscissa, displaying dimensional parameters being in good accordance with those of ones still standing on the west side of the survey area was clearly revealed. Moreover, some regular anomalies, which can be attributed to the remains of the watchtower in question and various wall ruins, were successfully traced from the GPR depth slices. The existence of an antisymmetric geometry for the consecutive archaeological structure under investigation was also determined in the survey area. Combining all of that information, a possible 3D virtual image of the military headquarters was then created, and this pointed out a small square quadriburgia characteristic of the structure investigated. Thus, we can conclude that the integration of GPR and ERT and imaging techniques used in the evaluation were quite effective to provide useful prior information for the subterranean targets in the non‐excavated parts of the ancient city. An archaeological evaluation by trial trenching is therefore required to confirm the results of the archaeo‐geophysical survey in the investigation area.
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Bitlis Eren üniversitesi fen bilimleri dergisi, Jun 15, 2020
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Journal of Applied Geophysics, 2021
Abstract Water resources are fundamental components of ecological life that must be maintained si... more Abstract Water resources are fundamental components of ecological life that must be maintained since they are at the risk of both pollution and depletion. Recently, one of the main factors threatening water resources is the groundwater salinization. In this study, electrical resistivity method via vertical electrical sounding (VES) technique and time-domain induced polarization (IP) method were applied on 34 points to show the electrical characteristic of the coastal area of Dikili district, NW Izmir, Turkey. Possible freshwater/seawater interface and the existence of the geothermal potential were successfully elucidated by a joint interpretation of the results inferred from both methods. Four different types of water resources were classified according to the apparent resistivity and chargeability values, which is freshwater ( msec.), geothermal water (8–150 Ω.m and > 14,000 msec.) and mixed water (0.5–60 Ω.m and 200–1600 msec.). To show the temporal and spatial change of the geo-electrical properties in the subsurface, geoelectrical sections obtained from 1D and 2D inversion of resistivity data were compared with those of an electrical resistivity survey conducted on 119 VES points in 1978 by the General Directorate of State Hydraulic Works (DSI in Turkish acronym). The results of this study highlight significant areas where the resistivity values are lower than
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Journal of Applied Geophysics, 2021
Abstract Doliche is an ancient city located at the northern fringe of Gaziantep in SE Turkey. The... more Abstract Doliche is an ancient city located at the northern fringe of Gaziantep in SE Turkey. The settlement spreads over a shallow hill called Keber Tepe. However, the lack of visible remains on the surface severely limits the comprehension of the spatial organization of the site. To understand the ancient city layout, but also to identify promising starting points of archaeological investigations, geophysical exploration plays a substantial role. In 2019 and 2020 campaigns, ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) surveys were conducted to determine anthropogenic structures in selected three study areas (SA) of the hill. Among them, SA-1 is adjacent to an excavation area on the south slope of the hill, where a large three-aisled Christian basilica had been discovered. SA-2 is in the eastern part of the city area, next to a sizeable civic bath building of the Roman period. Lastly, SA-3 covers the mosaic floor of the central nave and the terrace of the basilica where archaeological excavations were carried out in 2020 compaign. Archaeo-geophysical survey presented a challenging task as Keber Tepe is mainly composed of clayish-limestone and the same material had been used for architectural construction. Despite the disadvantages, GPR provided partial traces of the nave walls conforming with the existing basilica structures. The archaeological trenchs conducted in SA-3 confirm the partial reflection properties observed in the GPR sections. ERT surveys in this area provided subsurface models containing traces of anthropogenic structures unearthed. Since the findings obtained from both methods support each other very well in SA-2, we assumed that the field condition in this region of the hill is different or buried materials have lesser clay content in comparison to SA-1 and SA-3. As a result, the archaeo-geophysical survey contributed to the understanding of the archaeological structures and help to identify promising areas for further archaeological excavations.
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ABSTRACT
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ABSTRACT
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Journal of Geophysics and Engineering, 2012
Three naturally inspired meta-heuristic algorithms—the genetic algorithm (GA), simulated annealin... more Three naturally inspired meta-heuristic algorithms—the genetic algorithm (GA), simulated annealing (SA) and particle swarm optimization (PSO)—were used to invert some of the self-potential (SP) anomalies originated by some polarized bodies with simple geometries. Both synthetic and field data sets were considered. The tests with the synthetic data comprised of the solutions with both noise-free and noisy data; in the tests
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Journal of Geophysics and Engineering, 2014
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GEOPHYSICS, 2012
Geophysical survey techniques have been successfully applied to near-surface cave detection in ka... more Geophysical survey techniques have been successfully applied to near-surface cave detection in karstic terrains. We used magnetic and electrical resistivity surveys to delineate the karstic structure of the Ayvacık Sinkhole, which may be considered to be a vertical cave. The magnetic-total-field-anomaly map helped reveal the metamorphic and sedimentary units in the study area. The total-horizontal-gradient map, which was based on a calculated pseudogravity anomaly, successfully identified the contact between the limestone unit and the cave system. Using these results, we positioned and carried out a vertical electrical sounding (VES) survey with a Schlumberger array along a line that consisted of 11 stations. The VES data were then processed using a 1D global optimization technique, which used a genetic algorithm and a 2D linearized least-squares algorithm. The results were generally in good agreement with each other, and together they pointed out three geologic layers: (1) an overb...
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TURKISH JOURNAL OF EARTH SCIENCES, 2019
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The occurrences of the 1999 (Mw 7.4) Kocaeli and (Mw 7.1) Diuzce earthquakes in Turkey once again... more The occurrences of the 1999 (Mw 7.4) Kocaeli and (Mw 7.1) Diuzce earthquakes in Turkey once again demonstrate the behavioral importance of reinforced concrete (RC) shear-wall dominant structures that commonly built by using tunnel form technique. Reported non-...
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Journal of Geophysics and Engineering
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Papers by Çağlayan Balkaya