Collaborative Research: RIPS Type 2: Vulnerability Assessment and Resilient Design of Interdependent Infrastructures

现代基础设施系统，例如电网、通信网络和运输网络，是相互依赖的，使得一个系统中的元件的故障可能导致其他系统中的元件的多个故障。这个过程可以在相互依赖的系统之间以级联方式来回传播，导致灾难性的广泛故障。此外，人类行为的多样性对干扰，如司机？对交通堵塞的反应，会使级联行为进一步复杂化。在这个项目中，来自计算机科学、优化、运输系统、电力工程和社会科学领域的五名研究人员将共同努力，更好地理解级联故障现象，开发用于设计弹性相互依赖系统的易于处理的数学模型，研究创新战略，通过防止连锁故障的发生和快速恢复系统运行，增强相互依赖系统的恢复能力。这项研究将为理解相互依赖系统在中断情况下的鲁棒性奠定基础，从而推动现代复杂网络理论和优化算法的发展。该项目的变革贡献如下。研究人员将提供第一个模型，可以描述的规模和深度的级联故障在相互依赖的系统，介绍新的概念？人类脆弱性？并提供了第一个基于可服务性识别关键网络元件的模型。研究结果将为公共和私营机构提供及时的支持，以更好地了解连锁故障的影响和保护关键要素的影响，并制定政策以提高相互依赖的基础设施系统的复原力。特别是，研究结果可能会使这些政策的选择多样化，以管理交通网络和电网。研究成果还将丰富网络科学、图论、优化、通信、运输系统、电力工程和社会科学领域的文献。该项目将涉及各级学生，重点是吸引代表性不足群体的学生。通过结合理论（数学建模和优化）和应用（领域专业知识）方法，该项目将全面研究相互依赖系统中的脆弱性和弹性问题。作为实现这一目标的具体步骤，研究人员将进行五个跨学科的研究任务：1）通过数学量化级联的“深度”和“广度”来分析相互依赖系统中级联故障的机制; 2）识别关键要素（节点和/或链接），其删除会导致相互依赖系统的恢复力的最大损失;（3）通过优化网络间的连接来增强相互依赖系统的弹性，并在系统衰退到全面失效之前找到自适应控制策略来快速反应级联行为; 4）调查与关键要素相关的“人的脆弱性”，并得出人的脆弱性的度量，这些数据将进一步纳入相互依存系统的数学模型，以完善对关键要素的检测; 5）将所提出的严格数学模型和算法应用于佛罗里达的现实世界中相互依赖的网络，该网络由电网、通信网络和交通网络组成，具有人类行为的影响。

Modern infrastructure systems, such as power grids, communication networks, and transportation networks are interdependent in such a way that a failure of an element in one system may cause multiple failures of elements in other systems. This process can propagate back and forth between interdependent systems in a cascading fashion, resulting in a catastrophic widespread failure. In addition, the diverse human behaviors to disruptions, such as drivers? reaction to gridlock, can further complicate the cascading behaviors. Radically new models and analytical techniques are needed to assess and design resilient interdependent systems.In this project, a team of five investigators from the domains of computer science, optimization, transportation systems, power engineering, and social science will work together to gain a better understanding of cascading failure phenomena, develop tractable mathematical models for designing resilient interdependent systems, and investigate innovative strategies to enhance the resilience of interdependent systems by preventing the occurrence of cascading failures and quickly restoring system operations. This research will lay a foundation in understanding the fundamental properties that contribute to the robustness of interdependent systems under disruptions, and thus, advancing the state-of-the-art in modern complex network theory and optimization algorithms. The transformative contributions of the project are as follows. The investigators will offer the first models that can characterize the scale and depth of cascading failures in interdependent systems, introduce the new concept of ?human vulnerability?, and provide the first model on identifying critical network elements based on serviceability. The findings of the research will provide timely support for public and private agencies to better understand the impacts of cascading failures and the implications of protecting critical elements, and develop policies to enhance the resilience of the interdependent infrastructure systems. In particular, the findings can potentially diversify the choices of these policies for managing transportation networks and power grids. The research results will also enrich the literature in the areas of network science, graph theory, optimization, communications, transportation systems, power engineering, and social science. The project will involve students at all levels, with emphasis on attracting students from underrepresented groups. The real-world applications will offer an ideal platform to engage undergraduate and K-12 students and to reach out to practitioners and policy makers.Via a combination of theoretical (mathematical modeling and optimization) and applied (domain expertise) approaches, this project will comprehensively investigate vulnerability and resilience issues in interdependent systems. As specific steps towards this goal, the investigators will pursue five interdisciplinary research tasks: 1) analyzing the mechanisms of cascading failures in interdependent systems by mathematically quantifying the "depth" and "breadth" of cascades; 2) identifying critical elements (nodes and/or links) whose removal yields the most significant loss of resilience of interdependent systems; 3) enhancing the resilience of interdependent systems via optimal addition of inter-network links and finding adaptive control strategies to rapidly react to the cascading behaviors before the systems decay into full-blown failure; 4) investigating "human vulnerability" associated with critical elements, and deriving metrics of human vulnerability, which will be further integrated into the mathematical models of interdependent systems to refine the detection of critical elements; 5) applying the proposed rigorous mathematical models and algorithms to the real-world interdependent networks in Florida, which consist of power grids, communication networks, and transportation networks, with an impact of human behavior.