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1.
Uncertainty modeling and stability assessment of minimum spanning trees in network design
Ahmad Hosseini, 2024, original scientific article

Abstract: The Minimum Spanning Tree (MST) problem in networks focuses on finding efficient routes, with applications in transportation, logistics, telecommunications, and more. However, catastrophes can make these networks uncertain, requiring robust computational models for decision-making. This paper introduces an uncertainty theory-based model to analyze the stability of MSTs in uncertain networks. By incorporating reliability and risk variables, we assess the robustness of uncertain MSTs (UMSTs) and address the challenge of computing link tolerances, which define the range within which network links can vary without compromising MST optimality. This study proposes computational formulations to systematically calculate these tolerances, offering a more efficient alternative to traditional re-optimization methods.
Keywords: operations research, transportation, sensitivity analysis, uncertainty, reliability
Published in RUNG: 03.12.2024; Views: 118; Downloads: 0
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2.
Max-type reliability in uncertain post-disaster networks through the lens of sensitivity and stability analysis
Ahmad Hosseini, 2024, original scientific article

Abstract: The functionality of infrastructures, particularly in densely populated areas, is greatly impacted by natural disasters, resulting in uncertain networks. Thus, it is important for crisis management professionals and computer-based systems for transportation networks (such as expert systems) to utilize trustworthy data and robust computational methodologies when addressing convoluted decision-making predicaments concerning the design of transportation networks and optimal routes. This study aims to evaluate the vulnerability of paths in post-disaster transportation networks, with the aim of facilitating rescue operations and ensuring the safe delivery of supplies to affected regions. To investigate the problem of links' tolerances in uncertain networks and the resiliency and reliability of paths, an uncertainty theory-based model that employs minmax optimization with a bottleneck objective function is used. The model addresses the uncertain maximum reliable paths problem, which takes into account uncertain risk variables associated with links. Rather than using conventional methods for calculating the deterministic tolerances of a single element in combinatorial optimization, this study introduces a generalization of stability analysis based on tolerances while the perturbations in a group of links are involved. The analysis defines set tolerances that specify the minimum and maximum values that a designated group of links could simultaneously fluctuate while maintaining the optimality of the max-type reliable paths. The study shows that set tolerances can be considered as well-defined and proposes computational methods to calculate or bound such quantities - which were previously unresearched and difficult to measure. The model and methods are demonstrated to be both theoretically and numerically efficient by applying them to four subnetworks from our case study. In conclusion, this study provides a comprehensive approach to addressing uncertainty in reliability problems in networks, with potential applications in various fields.
Keywords: Disaster Management, Network Reliability, Stability Analysis, Transportation, Uncertainty
Published in RUNG: 24.11.2023; Views: 1524; Downloads: 6
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3.
Systematic uncertainty in the analysis of the TA fluorescence detector from fluorescence yield models
Kohei Komori, R. U. Abbasi, Y. Abe, T. Abu-Zayyad, M. Allen, Yasuhiko Arai, R. Arimura, E. Barcikowski, J. W. Belz, Douglas R. Bergman, 2023, published scientific conference contribution

Abstract: Ultra-high energy cosmic rays have been observed by various experiments such as Telescope Array (TA) and the Pierre Auger Observatory (Auger). There are differences in the energy spectra measured by TA and Auger. One reason for this difference is systematic uncertainty in the energy determination. The fluorescence yield model, which consists of fluorescence emission efficiencies and spectra, is one of the most significant components of this systematic uncertainty. Fluorescence emission efficiencies and spectra have been measured in various experiments, and different measurements are currently used to determine the energy of the TA and Auger experiments. In this study, we estimate the influence of the fluorescence yield model on the systematic uncertainty in the energy determination of the TA fluorescence detector.
Keywords: Telescope Array, TAx4, indirect detection, fluorescence detection, fluorescence yield, ultra-high energy, cosmic rays, energy uncertainty
Published in RUNG: 09.10.2023; Views: 2054; Downloads: 6
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4.
Uncertain Most Reliable Data Transmission Path: A Chance-Constrained Scenario with Risk Considerations
Ahmad Hosseini, 2015, invited lecture at foreign university

Keywords: Uncertainty, Most Reliable Path, Chance-Constrained
Published in RUNG: 15.02.2023; Views: 1598; Downloads: 0
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5.
Connectivity reliability in uncertain networks with stability analysis
Ahmad Hosseini, Eddie Wadbro, 2016, original scientific article

Keywords: Traffic network, Uncertainty theory, Reliability, Chance-constrained, Stability analysis
Published in RUNG: 14.02.2023; Views: 1758; Downloads: 0
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THE CALIBRATION PROCESS OF A MANUFACTURING LINE IN THE AUTOMOTIVE INDUSTRY
Aleksandar Kuzmanovski, 2022, undergraduate thesis

Abstract: Calibration of measuring instruments in the industry is a process that is done regularly both internally by internal laboratories operating within the companies and externally by accredited external laboratories. The goal of the diploma thesis was to document and carry out the calibration process of a production line within a manufacturing plant, and to deliver a final report on the overall calibration. The result is obtained by calculating the combined uncertainty of the measurement process. As any measurement is gathered certain uncertainties are bound to influence the measurements, in our case we have three main uncertainties which are the standard uncertainty, uncertainty due to the resolution of the measuring instrument and the uncertainty from the calibration certificate from the measuring equipment that is used in the measurement process. The final combined uncertainty is calculated with the standard uncertainty which has a 68% confidence that the true value lies within that range therefore we need to expand the range to obtain a 95% confidence and we achieve this by multiplication of the combined uncertainty with the K = 2 factor.
Keywords: Metrology, calibration, adjustment, measurement errors, measurement uncertainty, measuring instruments, measuring equipment.
Published in RUNG: 05.01.2023; Views: 2262; Downloads: 45
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