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A detailed understanding of the many facets of the Internet's topological structure is critical for evaluating the performance of networking protocols, for assessing the effectiveness of proposed techniques to protect the network from nefarious intrusions and attacks, or for developing improved designs for resource provisioning. Previous studies of topology(More)
The search for unifying properties of complex networks is popular, challenging, and important. For modeling approaches that focus on robustness and fragility as unifying concepts, the Internet is an especially attractive case study, mainly because its applications are ubiquitous and pervasive, and widely available exposition exists at every level of detail.(More)
There is a large, popular, and growing literature on " scale-free networks " with the Internet along with metabolic networks representing perhaps the canonical examples. While this has in many ways reinvigorated graph theory, there is unfortunately no consistent, precise definition of scale-free graphs and few rigorous proofs of many of their claimed(More)
Building on a recent effort that combines a first-principles approach to modeling router-level connectivity with a more pragmatic use of statistics and graph theory, we show in this paper that for the Internet, an improved understanding of its physical infrastructure is possible by viewing the physical connectivity as an annotated graph that delivers raw(More)
Although the " scale-free " literature is large and growing, it gives neither a precise definition of scale-free graphs nor rigorous proofs of many of their claimed properties. In fact, it is easily shown that the existing theory has many inherent contradictions and verifiably false claims. In this paper, we propose a new, mathematically precise, and(More)
We propose a definition of infrastructure resilience that is tied to the operation (or function) of an infrastructure as a system of interacting components and that can be objectively evaluated using quantitative models. Specifically, for any particular system, we use quantitative models of system operation to represent the decisions of an infrastructure(More)
The Internet's layered architecture and organizational structure give rise to a number of different topologies, with the lower layers defining more physical and the higher layers more virtual/logical types of connectivity structures. These structures are very different , and successful Internet topology modeling requires annotating the nodes and edges of(More)
Recent efforts to develop a universal view of complex networks have created both excitement and confusion about the way in which knowledge of network structure can be used to understand, control, or design system behavior. This paper offers perspective on the emerging field of " network science " in three ways. First, it briefly summarizes the origins,(More)
— Considerable attention is now being devoted to the study of " complexity science " with the intent of discovering and applying universal laws of highly interconnected and evolved systems. This paper considers several issues related to the use of these theories in the context of critical infrastructures, particularly the Internet. Specifically, we revisit(More)
The concept of expertise is widely embraced but poorly defined in surgery. Dictionary definitions differentiate between authority and experience, while a third view sees expertise as a mind-set rather than a status. Both absolute and relative models of expertise have been developed, and each allows a richer understanding of the application of these concepts(More)