Istanbul Technical University
Ulusal Üniversitelerarası Açık Erişim Sistemi - İstanbul Teknik ÜniversitesiNot a member yet
67356 research outputs found
Sort by
A Pre-Emptive Scheduling Mechanism for Service Assurance of Network Slicing in Next Generation Cellular Networks
No full textAs the number of services and applications with diverse requirements keeps increasing, it is therefore of paramount importance to develop more efficient resource allocation techniques. In this paper, we propose a pre-emptive scheduling mechanism for managing network slices, specifically enhanced Mobile Broadband (eMBB) and Ultra-Reliable Low-Latency Communications (URLLC), in 5G and beyond (5GB) networks, leveraging network slicing to optimize resource management. The proposed mechanism effectively balances the trade-off among throughput, latency, and reliability by dynamically reallocating limited radio resources between two slices. Through system-level simulations, we demonstrate that the stringent latency requirements of the URLLC slice are satisfied while minimizing the eMBB throughput degradation. The simulation results indicate that, compared to traditional resource allocation techniques, the puncturing mechanism enhances resource utilization, offering a scalable solution for the latency and throughput requirements of 5GB networks.https://doi.org/10.1109/access.2025.3536997https://doi.org/10.1109/ACCESS.2025.3536997https://doaj.org/article/a2ca7eec2cf54a61824c1765a5baf90
Evaluation of the Performance of Soil-Nailed Walls in Weathered Sandstones Utilizing Instrumental Data
No full textUsed for soil and weathered rocks, soil nails are rigid reinforcements positioned at certain angles on the ground to provide slope stability. A rigid reinforcement element placed in a well filled with cement grout mix after completing drilling will generate adherence stress between the grout-mixed nail bar and soil. Due to this stress, load is transferred to the soil along the soil–grout interaction surface. In the case discussed herein, the slope at the parcel border needed to be made steeper in order to accommodate the construction of a facility in the Taşkısığı region of Sakarya province. Soil-nailed walls, which are inexpensive and suitable for weathered rocks, were needed as a support system because the slope was too steep to support itself. Support system performance was measured using two inclinometers and two soil nail pull-out tests conducted on different sections observed during and after construction. Contrary to the design-phase prediction, it was determined that the stresses started to dampen in the region closer to the slope-facing zone. Field measurement data and numerical analysis revealed that higher parameters than necessary were selected. In this context, sensitivity and parameter analyses were carried out using the Hoek–Brown constitutive model. The GSI value was re-evaluated and found to be compatible with the observation results obtained from the field performance. Since the retaining wall performance observed was higher than expected, geometric parametric analysis of the structural elements was performed; high safety coefficients were found across variations. The effects of the inclination of the slope, nail length, nail spacing, and nail slope design parameters on the safety coefficient and horizontal displacement were examined. The optimal design suggested nail lengths of 4.00 m, a spacing of 1.60 m, and slopes of 20°. It was discovered that the effect of the inclination degree of the slope on the safety coefficient was lower than expected. The results revealed that a more economical design with a similar safety factor can be obtained by shortening the lengths of the nails.https://doi.org/10.3390/app15062908https://doaj.org/article/13be7c1690154f43a0e79d2347b3b38
Modeling the effects of air pollution and meteorological variables on mortality from respiratory diseases: insights from the ARDL
No full texthttps://doi.org/10.1007/s13721-025-00547-
Determining Tree Locations via Satellite and Drone Data
No full texthttps://doi.org/10.1109/siu66497.2025.1111242
Vegetation History of Karacabey Longoz Forest and Surrounding Area During the Last 250 Years (Bursa, Türkiye)
No full textIn this study, a 24-cm-long sediment core was taken from Poyraz Lagoon located on the northern side of Karacabey district in Bursa, northwest of Türkiye, using KAJAK gravity core sampling. The bottom sediment was dated using one AMS radiocarbon date on bulk organic carbon. The 13δ corrected radiocarbon age was determined as 238±24 BP. Sediment sub-samples were taken at 4-cm intervals along this core, and pollen slides were prepared using the standard method. A total of 250 terrestrial pollen grains were counted in each sediment sample. The aim of this study was to determine the vegetation history of Karacabey Longoz (Floodplain) Forest and its surrounding area, which have diverse habitat mosaics, over the last 250 years. Palynological evidence indicates that the vegetation around this lagoon basin was dominated by Fraxinus, Alnus, Carpinus, Quercus (deciduous oaks), and Corylus. The increase in the pollen percentage of Fraxinus, Alnus, and Ulmus, which are characteristic species of Longoz forests, particularly in the KRC-2 zone, indicates that the presence of these taxa in the area has increased from 1850 AD to the present. Additionally, the increased pollen percentage of anthropogenic indicator species such as Castanea, Olea, Chenopodiaceae, and Poaceae in the upper zone of the pollen diagram indicates that the Longoz vegetation in this region has undergone changes due to human impact since 1850 AD.https://doi.org/10.26650/jgeog2024-1428426https://doaj.org/article/8231bdc6f19a4462aca729c43682fffchttps://hdl.handle.net/20.500.12831/24300https://aperta.ulakbim.gov.tr/record/27558
Conceptual Design of ML-Based Handover Models for UAV Networks in Disaster Scenarios
No full texthttps://doi.org/10.1109/isci65687.2025.1116744
A Multi-Objective Dynamic Resource Allocation Model for Search and Rescue and First Aid Tasks in Disaster Response by Employing Volunteers
No full textBackground: Each disaster has its specific resource requirements, varying based on its size, location, and the affected region’s socio-economic level. Pre-disaster planning and post-disaster dynamic resource allocation including material and human resources is essential. Methods: To address the resource allocation challenges in disaster response, a multi-objective two-stage stochastic programming model is developed for search and rescue and first aid activities. The model aims to minimize the total unmet human demand, the number of resources transferred between regions, and the total unmet material demand. The proposed model was solved for a real case of an expected earthquake in Istanbul’s Kartal district. The augmented epsilon constraint 2 algorithm was employed using the CPLEX solver. A sensitivity analysis was made. Results: Most of the unmet demand occurs in the first period. After that period, the unmet demand decreases with interregional transfers and additional resources. The model is robust to scenario probability and penalty value changes in the objectives. Conclusions: This is the first study that simultaneously and dynamically allocates renewable and non-renewable material resources and human resources, including the official rescue units and volunteers, for disaster response. Volunteers’ inclusion in teams considering their training and quitting behavior are unique aspects of the study.https://doi.org/10.3390/logistics9010041https://doaj.org/article/b985c72e3a7c4aab8bc000467d3a26c
An Enhanced Fraud Detection for Recommendation Systems
No full texthttps://doi.org/10.1109/ubmk67458.2025.1120696
Direct observation of small molecule activator binding to single PR65 protein
No full textAbstract The reactivation of heterotrimeric protein phosphatase 2A (PP2A) through small molecule activators is of interest to therapeutic intervention due to its dysregulation, which is linked to chronic conditions. This study focuses on the PP2A scaffold subunit PR65 and a small molecule activator, ATUX-8385, designed to bind directly to this subunit. Using a label-free single-molecule approach with nanoaperture optical tweezers (NOT), we quantify its binding, obtaining a dissociation constant of 13.6 ± 2.5 μM, consistent with ensemble fluorescence anisotropy results but challenging to achieve with other methods due to low affinity. Single-molecule NOT measurements reveal that binding increases optical scattering, indicating PR65 elongation. This interpretation is supported by all-atom molecular dynamics simulations showing PR65 adopts more extended conformations upon binding. This work highlights NOT’s utility in quantifying binding kinetics and structural impact, offering insights valuable for drug discovery.https://doi.org/10.1038/s44328-024-00018-7http://dx.doi.org/10.1038/s44328-024-00018-7https://www.repository.cam.ac.uk/handle/1810/37886