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Yayın GIS aided vulnerability assessment for roads(Springer Science and Business Media B.V., 2022-04-21) Çalışkan, Berna; Atahan, Ali Osman; Kesten, Ali SercanRoad networks are vulnerable to natural disasters such as floods, earthquakes and forest fires which can adversely affect the travel on the network. However, not all road links equally affect the travel conditions in a given network; typically some links are more critical to the network functioning than the others. The first stage of study involves the investigation of geological conditions. Image classification used for extracting information classes from ‘Geological Map of Istanbul area’ image file. The resulting raster layer used to create thematic map. A reclassification was performed for lithologic types. The second stage involves analyzing topological situation. A slope map prepared and classified according to percentage of slope values. The third phase is the analysis and interpretation of the accumulated data to establish suitable and applicable road vulnerability scores. The information in the source data for each vulnerability factor are classified into three different vulnerability scores: +2 (considerably increases vulnerability), +1 (increases vulnerability) and 0 (does not increase vulnerability) by using a vulnerability score table. The study area was categorized into three different traffic analysis zones as: (1) least favorable area; (2) favorable area; (3) most favorable area. Vulnerability values obtained to measure serviceability of critical links in dense urban road networks and applies them to the case of ‘Beyoğlu’ region. Thematic layers were prepared using the Geographic Information System (GIS), and they were then combined to produce the serviceability of road links in the ‘Beyoğlu’ region. Consequently, A site specific vulnerability index is proposed, considering the serviceability of road links. A conceptual flowchart of the GIS processing steps taken to obtain the vulnerability index is illustrated.Yayın Improving the calibration time of traffic simulation models using parallel computing technique(Institute of Electrical and Electronics Engineers Inc., 2019-06) Dadashzadeh, Nima; Ergün, Murat; Kesten, Ali Sercan; Zura, MarijanThe calibration procedure for traffic simulation models can be a very time-consuming process in the case of a large-scale and complex network. In the application of Evolutionary Algorithms (EA) such as Genetic Algorithms (GA) and Particle Swarm Optimization (PSO) for calibration of traffic simulation models, objective function evaluation is the most time-consuming step in such calibration problems, because EA has to run a traffic simulation and calculate its corresponding objective function value once for each set of parameters. The main contribution of this study has been to develop a quick calibration procedure for the parameters of driving behavior models using EA and parallel computing techniques (PCTs). The proposed method was coded and implemented in a microscopic traffic simulation software. Two scenarios with/without PCT were analyzed using the developed methodology. The results of scenario analysis show that using an integrated calibration and PCT can reduce the total computational time of the optimization process significantly-in our experiments by 50%-and improve the optimization algorithm's performance in a complex optimization problem. The proposed method is useful for overcoming the limitation of computational time of the existing calibration methods and can be applied to various EAs and traffic simulation software.Yayın Acoustic and structural design of a highway noise barrier(Institute of Physics Publishing, 2020-05-18) Kesten, Ali Sercan; Umut, Önder; Ayva, BurakHighway noise barriers are designed to mitigate the effects of traffic noise along the highway. Noise barriers primarily block the direct path of the sound between the source on the highway and the receiver exposed to the sound. Noise mitigation capability, aesthetics, cost and constructability and structural capacity against wind and earthquake loads are critical parameters to be considered in noise barrier design. The height and length of a noise barrier are determined by acoustical considerations, aesthetics and cost. In addition, the structural design of the noise barrier should meet the established standards. The aim of this study is to evaluate the noise mitigation capabilities, aesthetic features and costs of acoustic designs for the residential buildings located near the urban highway and evaluate the structural performances against wind and earthquake. Through the interviews, the designs higher than 10m are not found acceptable by the residents and also due to the aesthetic concerns the upper part of the noise barrier is set to be constructed as glass. Therefore, the noise reduction capabilities and construction cost and the alternatives that complies with the constraints are determined and the corresponding costs are calculated accordingly. Noise simulation software is used to identify the effectiveness of selected noise barriers and structural analysis and design software is used to evaluate the structural performance. The results show that designed precast lightweight concrete and glass composite noise barrier meet the required noise reduction goal along with a resilient structural performance and affordable cost.
