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Modern society's physical health depends vitally upon a number of real, interdependent, critical infrastructure networks that deliver power, petroleum, natural gas, water, and communications. Its economic health depends on a number of other infrastructure networks, some virtual and some real, that link residences, industries, commercial sectors, and(More)
Critical national infrastructures for power, emergency services, finance, and other basic industries rely heavily on information and telecommunications networks (voice, data, Internet) to provide services and conduct business. While these networks tend to be highly reliable, severe, large scale outages do occur, especially at times of unfolding disasters,(More)
Executive Summary Local, open-outbreak mitigation strategies for pandemic influenza that target zones of high infectious contact within a community's social network may be very effective. A networked agent-based model was used to instantiate the contact network within a stylized small town and vary the behavior of targeted groups. Simulations show that(More)
Infrastructure interconnections create chains of interdependencies that can propagate disturbances across many infrastructures and over long distances. The pattern of interconnections may tend to propagate, amplify, or dampen disturbances. System dynamics modeling can be to identify chains of interdependencies, arising from pervasive interconnection, which(More)
Infrastructures provide the foundation for national economic vitality, security and every day comforts. The systems, processes, facilities and experts that form these infrastructures are sophisticated, complex and highly interdependent. Over time, these physical, human and cyber components have evolved toward economical and efficient systems that are robust(More)
National and economic security and the quality of life in the U.S. depend on reliable operation of complex infrastructures. The National Infrastructure Simulation and Analysis Center, or NISAC, provides modeling and simulation capabilities for analyzing critical infrastructures. NISAC was founded by Congress in the late 90's as a joint effort between Sandia(More)
Complex adaptive systems-of-systems are inherently multi-scale across several dimensions, including temporal, geographical, and organizational. We present a multi-model paradigm integrating a community-scale individual-based model (IBM) to investigate the immediate effects of interventions with a population-scale system dynamics (SD) model to analyze(More)
In marine ecosystems, phage predation (phage-mediated cell lysis) is an important driver of bacterial mortality through host cell death and nutrient cycling through the release of cell contents. Both of these impacts increase marine microbial diversity by increasing interspecific competition. By contrast, very little is known about the role of phage(More)