Optimization Processes of Tangible and Intangible Networks through the Laplace Problems for Regular Lattices with Multiple Obstacles along the Way

A systematic approach is proposed to the theme of safety,reliability and global quality of complex networks(material and immaterial)by means of special mathematical tools that allow an adequate geometric characterization and study of the operation,even in the presence of multiple obstacles along the path.To that end,applying the theory of graphs to the problem under study and using a special mathematical model based on stochastic geometry,in this article we consider some regular lattices in which it is possible to schematize the elements of the network,with the fundamental cell with six,eight or 2(n+2)obstacles,calculating the probability of Laplace.In this way it is possible to measure the“degree of impedance”exerted by the anomalies along the network by the obstacles examined.The method can be extended to other regular and/or irregular geometric figures,whose union together constitutes the examined network,allowing to optimize the functioning of the complex system considered.

Resilience assessment framework toward interdependent bus-rail transit network:Structure,critical components,and coupling mechanism

Understanding the interdependent nature of multimodal public transit networks(PTNs)is vital for ensuring the resilience and robustness of transportation systems.However,previous studies have predominantly focused on assessing the vulnerability and characteristics of single-mode PTNs,neglecting the impacts of heterogeneous disturbances and shifts in travel behavior within multimodal PTNs.Therefore,this study introduces a novel resilience assessment framework that comprehensively analyzes the coupling mechanism,structural and functional characteristics of bus-rail transit networks(BRTNs).In this framework,a network performance metric is proposed by considering the passengers’travel behaviors under various disturbances.Additionally,stations and subnetworks are classified using the k-means algorithm and resilience metric by simulating various disturbances occurring at each station or subnetwork.The proposed framework is validated via a case study of a BRTN in Beijing,China.Results indicate that the rail transit network(RTN)plays a crucial role in maintaining network function and resisting external disturbances in the interdependent BRTN.Furthermore,the coupling interactions between the RTN and bus transit network(BTN)exhibit distinct characteristics under infrastructure component disruption and functional disruption.These findings provide valuable insights into emergency management for PTNs and understanding the coupling relationship between BTN and RTN.

韧性城市理论与评价方法综述

As global risks and disasters increase,resilience is needed to cope with risks and uncertainties.Cities are the subject of a large amount of resilience research.Hence resilient urban development covers many areas.Theoretical resilience research either focuses on a special field or extends over the context of a single analysis and evaluation system.There is a lack of multi-perspective comprehensive analysis and evaluation methods in the existing research.This paper reviews different theoretical frameworks of resilience through an induction method,and analyzes the resilience evaluation methods by means of literature-based measurement and visual expression methods.Based on the theoretical frameworks,this paper develops a model integrating different resilience analysis types and extends it to four interrelated dimensions in order to visualize the correspondence between the analysis frameworks and the evaluation methods.Finally,the paper develops a comprehensive approach to resilience analysis and evaluation,which is of great significance for understanding how resilient cities operate.

Characterizing Uncertainty in City-Wide Disaster Recovery through Geospatial Multi-Lifeline Restoration Modeling of Earthquake Impact in the District of North Vancouver

Restoring lifeline services to an urban neighborhood impacted by a large disaster is critical to the recovery of the city as a whole.Since cities are comprised of many dependent lifeline systems,the pattern of the restoration of each lifeline system can have an impact on one or more others.Due to the often uncertain and complex interactions between dense lifeline systems and their individual operations at the urban scale,it is typically unclear how different patterns of restoration will impact the overall recovery of lifeline system functioning.A difficulty in addressing this problem is the siloed nature of the knowledge and operations of different types of lifelines.Here,a city-wide,multi-lifeline restoration model and simulation are provided to address this issue.The approach uses the Graph Model for Operational Resilience,a data-driven discrete event simulator that can model the spatial and functional cascade of hazard effects and the pattern of restoration over time.A novel case study model of the District of North Vancouver is constructed and simulated for a reference magnitude 7.3 earthquake.The model comprises municipal water and wastewater,power distribution,and transport systems.The model includes 1725 entities from within these sectors,connected through 6456 dependency relationships.Simulation of the model shows that water distribution and wastewater treatment systems recover more quickly and with less uncertainty than electric power and road networks.Understanding this uncertainty will provide the opportunity to improve data collection,modeling,and collaboration with stakeholders in the future.