Multilevel resilience analysis of transportation and communication networks

Abstract

For many years the research community has attempted to model the Internet in order to better understand its behaviour and improve its performance. Since much of the structural complexity of the Inter- net is due to its multilevel operation, the Internet's multilevel nature is an important and non-trivial feature that researchers must consider when developing appropriate models. In this paper, we compare the normalised Laplacian spectra of physical-and logical-level topologies of four commercial ISPs and two research networks against the US freeway topology, and show analytically that physical level communication networks are structurally similar to the US freeway topology. We also generate synthetic Gabriel graphs of physical topologies and show that while these synthetic topologies capture the grid-like structure of actual topologies, they are more expensive than the actual physical level topologies based on a network cost model. Moreover, we introduce a distinction between geographic graphs that include degree-2 nodes needed to capture the geographic paths along which physical links follow, and structural graphs that eliminate these degree-2 nodes and capture only the interconnection properties of the physical graph and its multilevel relationship to logical graph overlays. Furthermore, we develop a multilevel graph evaluation framework and analyse the resilience of single and multilevel graphs using the flow robustness metric. We then confirm that dynamic routing performed over the lower levels helps to improve the performance of a higher level service, and that adaptive challenges more severely impact the performance of the higher levels than non-adaptive challenges.

Framework for improving the resilience and recovery of transportation networks under geohazard risks

“…Callaway et al [7] have used GCC to describe network robustness and percolation thresholds on random graphs. This metric is also applied to railway, air, and cargo transportation; communications; and multiplex networks to assess the robustness and/or resilience of networks and flow robustness [42,45,46,9].…”

Accurately and quickly calculating the weighted spectral distribution

“…According to the study of Cetinkaya et al [15,16], the NLS is quasi-symmetrical about 1 for a connected network. Specifically,…”

“…a CCDF of node degree. b Eigenvalue distributions of the WSD calculated using the ASLI, where the x-axis denotes eigenvalues from 0 to 1 because the NLS is quasi-symmetrical about 1 for a connected network [15,16] The theory and applications of the WSD in AS-level Internet topologies have been widely studied in the literature [6,[20][21][22]25]. Our contributions further enhance the importance of the WSD measure in AS-level Internet topologies because the network sizes of these topologies evolve and increase over time.…”

“…The largest eigenvalue, i.e., the spectral radius, of a graph is an important graph parameter [14]. Cetinkaya et al [15,16] correlated the graph diversity with the spectral radius of the normalized Laplacian spectrum (NLS). Additionally, comparing with the spectral radii of adjacency and Laplacian spectra, Cetinkaya et al [15,16] found that the spectral radius of the NLS is an ideal measure for comparing the connectivity of graphs with different sizes.…”

Embedded mobile crowd service systems based on opportunistic geological grid and dynamical segmentation

“…With the rapid development of embedded system and mobile communication network [1], the above technologies are applied in the description of the geological environment, the location of the landmarks, and the business of the exploration information. The embedded system and mobile communication network technology are used to satisfy the core requirements of geographic information system, such as geological information, map data, and multimedia data [2], which has been the research hot issue in the academic field [3].…”