Scopushttps://hdl.handle.net/11729/16822024-03-29T01:20:48Z2024-03-29T01:20:48ZImaging of rough surfaces by RTM methodSefer, AhmetYapar, AliYelkenci, Tanjuhttps://hdl.handle.net/11729/59322024-03-19T14:50:19Z2024-01-01T00:00:00ZImaging of rough surfaces by RTM method
Sefer, Ahmet; Yapar, Ali; Yelkenci, Tanju
An electromagnetic imaging framework is implemented utilizing a single frequency reverse time migration (RTM) technique to accurately reconstruct inaccessible two-dimensional (2D) rough surface profiles from the knowledge of scattered field data. The unknown surface profile, which is expressed as a 1D height function, is either perfectly electric conducting (PEC) or an interface between two penetrable media. For both cases, it is assumed that the surface is illuminated by a number of line sources located in the upper medium. The scattered fields, which should be collected by real measurements in practical applications, are obtained synthetically by solving the associated direct scattering problem through the surface integral equations. RTM is subsequently applied to generate a cross-correlation imaging functional which is evaluated numerically and provides a 2D image of the region of interest. A high correlation is observed by the functional in the regions where the transitions between two media occur. Hence, it results in the acquisition of the unknown surface profile at the sites where the functional attains its highest values. The efficiency of the proposed method is comprehensively tested by numerical examples covering various types of scattering scenarios.
2024-01-01T00:00:00ZMicroservices-based databank for Turkish hazelnut cultivars using IoT and semantic web technologiesAydın, ŞahinAldara, Dieaahttps://hdl.handle.net/11729/59312024-03-19T14:51:30Z2024-01-01T00:00:00ZMicroservices-based databank for Turkish hazelnut cultivars using IoT and semantic web technologies
Aydın, Şahin; Aldara, Dieaa
Information and communication technologies (ICTs) can play a crucial role in facilitating access to comprehensive information on the quality standards of Turkish hazelnut cultivars. In this regard, this study introduces a Hazelnut Databank System (HDS) that utilizes the microservices architecture, an integrated software system supported by the Internet of Things (IoT) and semantic web, to categorize Turkish hazelnut cultivars. The study focuses on developing microservices using various programming languages and frameworks. Specifically, C# on the.NET Core Framework was used for both microservices and the web-based application implemented through the ASP.NET Core MVC Framework. Mobile-based software applications were created using Xamarin. Forms, and the IoT application was developed using the Python programming language. The data storage is facilitated through the MS SQL Server database. Additionally, the study incorporates the implementation of a hazelnut species classification system using the DNN + ResNet50 machine learning model, achieving an impressive accuracy rate of 95.77%. The overall usability of the system was evaluated, resulting in a score of 42 out of 50. By providing detailed information on Turkish hazelnut cultivars, the HDS has the potential to greatly improve hazelnut production quality in Turkey and increase awareness of hazelnut agriculture among relevant stakeholders.
2024-01-01T00:00:00ZThe impact of the COVID-19 pandemic on online grocery supply chain management: a case study in IstanbulJavadi, SonyaKeten, OlcayÖzer, A. İhsanAlkan, R. Zeynephttps://hdl.handle.net/11729/59292024-03-15T19:15:20Z2024-03-01T00:00:00ZThe impact of the COVID-19 pandemic on online grocery supply chain management: a case study in Istanbul
Javadi, Sonya; Keten, Olcay; Özer, A. İhsan; Alkan, R. Zeynep
The COVID-19 pandemic has already crippled normal life all over the world. Its negative impact not only changed the human health system tragically but also disrupted the global economic system. One negative result was ended up in the global food supply chain. As the lockdown times have suspended the manufacturing and logistic activities, therefore, the customers have experienced unimaginable chaos in the shopping markets. Moreover, the purchasing habit of the consumers has remarkably changed compared to pre-pandemic. To meet this new demand pattern, many grocery retailers have tried to adapt to the new normal. While before COVID-19 offline grocery purchasing was popular, after the pandemic, online service got tremendous attention in market. In this study, online grocery supply chain management during the COVID-19 in Istanbul is considered. The aim is to find out how online grocery companies will serve more efficiently during the pandemics and which factors have more effect on the customer’s satisfaction. To do so, first, three popular grocery retailers in Istanbul were selected. Then, a related survey was designed to understand the consumer experience as doing online grocery shopping in COVID-19. Unsurprisingly, a result shows that 60% of the respondents did online shopping every 3-4 days in one week, and the delivery time is the most important factor for the customers. Then, the SWOT analyses were performed accordingly, and the related strategies were summarized. Finally, several managerial implications were given to may improve the company’s online services in COVID-19 and post COVID-19 in Turkey.
2024-03-01T00:00:00ZImpact of climate change and land cover dynamics on nitrate transport to surface watersBoyacıoğlu, HülyaGunecti, Mert CanBarbaros, FilizGül, AliGül, Gülay OnuşluelÖztürk, TuğbaKurnaz, M. Leventhttps://hdl.handle.net/11729/59062024-03-25T17:21:01Z2024-03-01T00:00:00ZImpact of climate change and land cover dynamics on nitrate transport to surface waters
Boyacıoğlu, Hülya; Gunecti, Mert Can; Barbaros, Filiz; Gül, Ali; Gül, Gülay Onuşluel; Öztürk, Tuğba; Kurnaz, M. Levent
The study investigated the impact of climate and land cover change on water quality. The novel contribution of the study was to investigate the individual and combined impacts of climate and land cover change on water quality with high spatial and temporal resolution in a basin in Turkey. The global circulation model MPI-ESM-MR was dynamically downscaled to 10-km resolution under the RCP8.5 emission scenario. The Soil and Water Assessment Tool (SWAT) was used to model stream flow and nitrate loads. The land cover model outputs that were produced by the Land Change Modeler (LCM) were used for these simulation studies. Results revealed that decreasing precipitation intensity driven by climate change could significantly reduce nitrate transport to surface waters. In the 2075–2100 period, nitrate-nitrogen (NO3-N) loads transported to surface water decreased by more than 75%. Furthermore, the transition predominantly from forestry to pastoral farming systems increased loads by about 6%. The study results indicated that fine-resolution land use and climate data lead to better model performance. Environmental managers can also benefit greatly from the LCM-based forecast of land use changes and the SWAT model’s attribution of changes in water quality to land use changes. Graphical abstract: (Figure presented.).
This research was supported by the 1003 Programme of the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant Agreement No 116Y423.
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