SOS 220: Lecture I1 (2023-04-17): Network Science and Applications скачать в хорошем качестве

SOS 220: Lecture I1 (2023-04-17): Network Science and Applications

In this lecture, we finish up our discussion of the Hawk–Dove (chicken) model as a game-theoretic exploration of commons/common-pool resources problems (and the tragedy of the commons). We contrast the Hawk–Dove with the stag hunt (public goods problem). Putting them together helps illustrate the idea of "network effects" from economics and motivates why looking at "networks" more formally might lead to understanding other macroscale phenomena. That lets us transition to Stanley Milgram and his experiment with letters that led to the "six degrees of separation" "small-world network" observation about human society. We discuss how network science provides a formal set of tools behind this network thinking and then provide the graph-theoretic ideas necessary to speak this language (nodes, edges, hubs, clusters, degree, degree distribution, etc.). We use Google PageRank as an example of how degree can be a useful tool for differentiating between nodes in a network and then start to discuss a formal definition of small-world networks and, eventually, scale-free networks. We will finish discussing scale-free networks in the next lecture. This lecture is based on topics from Chapters 15 and 16 from Melanie Mitchell's 2009 Complexity book. Whiteboard notes for this lecture can be found at: https://www.dropbox.com/s/u4t7v0m878b... This lecture was recorded by Theodore Pavlic as part of SOS 220 (Systems Thinking) at Arizona State University.