Robustness analysis metrics for worldwide airport network：A comprehensive study

Robustness of transportation networks is one of the major challenges of the 21 st century.This paper investigates the resilience of global air transportation from a complex network point of view,with focus on attacking strategies in the airport network,i.e.,to remove airports from the system and see what could affect the air traffic system from a passenger＇s perspective.Specifically,we identify commonalities and differences between several robustness measures and attacking strategies,proposing a novel notion of functional robustness：unaffected passengers with rerouting.We apply twelve attacking strategies to the worldwide airport network with three weights,and evaluate three robustness measures.We find that degree and Bonacich based attacks harm passenger weighted network most.Our evaluation is geared toward a unified view on air transportation network attack and serves as a foundation on how to develop effective mitigation strategies.

Why are COVID-19 travel bubbles a tightrope walk?An investigation based on the Trans-Tasmanian case

The COVID-19 pandemic has hit the transportation sector hard;particularly air transportation,as a major mode of long-distance transportation,has been affected tremendously.Since the dawn of COVID-19,politicians and policy makers have discussed the idea of introducing travel bubbles between countries(or counties),to allow for a continued exchange of people and goods.The eponymous Trans-Tasmanian travel bubble is a major example,involving quarantine-free travel between Australia and New Zealand.While both countries have tried to form a travel bubble various times,recurring setbacks and difficulties were faced.In October 2021,this ambitious project presumably has come to an end,with both countries announcing the essential capitulation of their COVIDZero strategies and a planned opening towards broader international travel.In this study,we perform a close investigation of the history behind the Trans-Tasmanian travel bubble as an on-off relationship,identifying a set of drivers for the serious problems involving a sustainable setup and operation.We develop a framework which represents important factors for successful travel bubbles and believe that the satisfaction of all factors at once is extremely challenging.Our results and insights are not specific to the Trans-Tasmanian case only,although it is taken as a running example,but can be generalized to various scales and environments.We hope that our study contributes to the literature by improving our understanding of the highly buzzed travel bubble concept,while providing empirical evidence for the troubles that inherently make such bubbles a tightrope walk.

Exploiting global information in complex network repair processes

Robustness of complex networks has been studied for decades,with a particular focus on network attack.Research on network repair,on the other hand,has been conducted only very lately,given the even higher complexity and absence of an effective evaluation metric.A recently proposed network repair strategy is self-healing,which aims to repair networks for larger components at a low cost only with local information.In this paper,we discuss the effectiveness and efficiency of self-healing,which limits network repair to be a multi-objective optimization problem and makes it difficult to measure its optimality.This leads us to a new network repair evaluation metric.Since the time complexity of the computation is very high,we devise a greedy ranking strategy.Evaluations on both real-world and random networks show the effectiveness of our new metric and repair strategy.Our study contributes to optimal network repair algorithms and provides a gold standard for future studies on network repair.

GraphCast for solving the air transportation nexus among safety,efficiency,and resilience

1.Overview Air transportation is built around three major corner stones:safety,efficiency,and resilience.Interactions between these three elements make the optimization of operations tremendously difficult,since focusing on one objective often has detrimental effects on others.Safety measures,comprised of stringent regulations,advanced technology,and comprehensive training,not only contribute to the mitigation of risks but also enable long-term efficiency gains by preventing costly disruptions and increasing passenger confidence.Furthermore,safety protocols improve the air transportation system's resilience,enabling it to withstand unforeseen events.Efficiency,achieved through highly tuned operations and streamlined processes,can sometimes challenge resilience through compromising redundancy;however,when balanced well,efficiency frees up resources that increase the resilience through robust contingency plans.The delicate interactions between safety,efficiency,and resilience in air transportation require a dynamic equilibrium,continuous innovation and adaptation for a safe,efficient,and adaptable air transportation system(Gössling,2020).