Impact Of Link Failures Research Articles

Network vulnerability analysis based on the overall and inequity impacts of the distribution of the added travel time to the network users

Vulnerability has been a major concern in the performance evaluation of transportation networks. In the concept of vulnerability, the key step is to identify the critical link, which are the ones susceptible to severe operational degradation caused by any type of failure. Several studies have been devoted to this issue by introducing indicators that illustrate the network's operational degradation's overall impact. However, the impact of the interrupted network on users can be further evaluated using the inequity perspective. Here, we present a method to assess network vulnerability to operational degradation based on spatial inequity impacts. The importance of a link is determined by calculating the Gini-coefficient of the distribution of added travel time to the users when the link is disabled. Furthermore, the overall impact of link failure is calculated based on the total extra travel time. The final link's importance is determined by the non-dominated sorting method based on the Pareto optimality concept considering both overall and inequity objectives. Measures quantifying overall and inequity impacts of link failure allow planners to determine how this influences the disadvantaged distribution and help them make decisions associated with maintenance plans that consider link failure's equity impact.

Impact of link failures on the performance of multihop lightwave networks

The impact of link failures on the performance of multihop lightwave networks such as shufflenet (SN), hypercube (HC), is evaluated by detailed computer simulation study. The degradation in network throughput of the above networks due to link failures is compared for several routing schemes, namely store-and-forward (SF), hot-potato (HP), and single-buffer deflection (DF) routing. The throughput degradation due to link failures is found to be minimum for HP routing. The HC network is much better suited for surviving multiple failures than SN of the same size. The simulation study is also extended to consider the impact of link failures in multiwavelength shufflenet (MWSN) employing dynamic wavelength routing. For MWSN, the degradation in throughput increases with m, the number of wavelengths per fiber link.

Water Distribution Network Reliability: Connectivity Analysis

This paper presents a methodology to analyze the reliability of a regional water distribution network. The proposed reliability analysis method focuses on the impact of link failures on source-demand connectivity, which is used as a measure of the mechanical reliability of the network. The mechanical reliability index is computed using the minimum cut-set method. The identification of minimum cut-sets consists of four stages: (1) For source-demand pairs; (2) for individual demand nodes; (3) for a group of demand nodes; and (4) for all demand nodes in the system. By using the multiple-stage approach, the total number of simulations required in the analysis is greatly reduced. Computational efficiency of the minimum cut-set method is further enhanced by using a highly efficient embedded generalized network algorithm to solve the optimization model used in the simulations. The results from the reliability analysis can be used to locate crucial pipelines in the network whose failure will severely impair the source-demand connectivity. The developed methodology is applied to a large-scale regional water distribution network associated with the Metropolitan Water District of Southern California.