Résultats de recherche pour « Scenarios of Destruction »

Abstract As the interdependence within inter-city collaborative innovation networks intensifies, the threat posed by subject failures triggered by external shocks to the effective functioning of these networks becomes increasingly critical. This paper delves into the impact of various types of subject failures on the resilience of city cluster collaborative innovation networks. By categorizing subject failures into nine distinct modes, this study integrates two pivotal aspects of innovation network resilience—structure and function—into a unified research framework. Structural resilience is assessed through the maximum connectivity subgraph, while functional resilience is gauged using network efficiency. The findings reveal notable variations in the structure of collaborative innovation networks across different fields, alongside differing sensitivities to the network’s resistance to destruction due to subject failures. Moreover, it was observed that random subject failures associated with high city clustering coefficients exert minimal impact on the network's structural and functional destructiveness, whereas those linked to larger city degree centrality significantly disrupt both network structure and function. Furthermore, the V index is employed to compare the effects of subject failure indicators across nine modes, indicating that cities with higher degrees of centrality have the most profound impact on network resilience. Significantly, when subject failures reach a threshold of 10%, both the structural and functional aspects of the city cluster collaborative innovation network approach a collapse threshold. The outcomes of this research highlight the destructive characteristics of city cluster collaborative innovation networks and offer a theoretical foundation for developing targeted risk management strategies to ensure the network's sustainable development.

Abstract. The article examines the application of the PERT method (Program Evaluation and Review Technique) for expert-based duration assessment in analyzing alternative scenarios for eliminating the consequences of emergency structural failures. The study focuses on selecting the optimal organizational and technological solution for restoring damaged critical infrastructure under conditions of time constraints, uncertainty, and limited initial information. The PERT method, based on three-point time estimates (optimistic, most likely, and pessimistic), enables modeling of the time boundaries for each stage of emergency recovery operations. The study proposes and analyzes four scenarios: the use of traditional scaffolding, a scissor lift, a modular assembly platform, and a modular platform integrated with an Information and Mathematical Strengthening Optimization System (IMSOS). For each scenario, expert evaluation was conducted for the duration of nine key stages of the emergency recovery process, considering access to damaged structures, selection of support elements, execution of temporary reinforcement, and organization of deformation monitoring. The results of the comparative analysis demonstrated that the scenario involving the modular platform combined with IMSOS is the most effective in terms of minimizing the total project duration. The proposed approach allows engineers and project teams to quickly adapt organizational and technological decisions to emergency conditions, reduce the risk of delays, and ensure timely restoration of structural functionality.

Future trajectories of the stratospheric trace gas background will alter the rates of bromine- and chlorine-mediated catalytic ozone destruction via changes in the partitioning of inorganic halogen reservoirs and the underlying temperature structure of the stratosphere. The current formulation of the bromine alpha factor, the ozone-destroying power of stratospheric bromine atoms relative to stratospheric chlorine atoms, is invariant with the climate state. Here, we refactor the bromine alpha factor, introducing normalization to a benchmark chemistry–climate state, and formulate Equivalent Effective Stratospheric Benchmark-normalized Chlorine (EESBnC) to reflect changes in the rates of both bromine- and chlorine-mediated ozone loss catalysis with time. We show that the ozone-processing power of the extrapolar stratosphere is significantly perturbed by future climate assumptions. Furthermore, we show that our EESBnC-based estimate of the extrapolar ozone recovery date is in closer agreement with extrapolar ozone recovery dates predicted using more sophisticated 3-D chemistry–climate models than predictions made using equivalent effective stratospheric chlorine (EESC).