CS 346U Exploring Complexity in Science and Technology Instructor: Melanie Mitchell Textbook: M. Mitchell, Complexity: A Guided Tour (Oxford University Press)

Note: All slides for a lecture will be available on the class webpage before each lecture:

What are Complex Systems?

Large networks of simple interacting elements, which, following simple rules, produce emergent, collective, complex behavior. What are Complex Systems?

Insect colonies video1 video2

Brains video

Immune system videovideo (+47sec.)

Economies Schweitzer et al., Science, 325, ,

Food webs

Genetic Regulatory Networks

World-Wide Web

Social Networks

a.html Cities

Do these systems have anything in common?

Central question for the sciences of complexity How do large networks with — simple components — limited communication among components — no central control — simple rules of operation give rise to complex (“adaptive”, “living”, “intelligent”) behavior, involving — information processing and computation — complex pattern dynamics — evolution and learning?

Core disciplines of the science of complexity Dynamics: The study of continually changing structure and behavior of systems Information: The study of representation, symbols, and communication Computation: The study of how systems process information and act on the results Evolution: The study of how systems adapt to constantly changing environments

Goals of the Science of Complexity Cross-disciplinary insights into complex systems General theory

Methodologies

Course Details Course web page: Textbook: Mitchell, Complexity: A Guided Tour My office hours: T, Th 3-4pm

Netlogo We will use Netlogo to illustrate / experiment with complex systems ideas. Part of first assignment is to download Netlogo. Bring laptop to class if possible.

Assignments Weekly homework assignments: reading, writing, Netlogo Term project: –Build simulation in Netlogo –Experiments using simulation –Read 2 (or more) published paper related to topic of simulation –Write term paper on simulation, results, related papers pages, double-spaced, including figures and references We will spend time in class learning Netlogo and formulating/working on final projects.

Grading Homework: 60% Term project and writeup: 40%

Class Rules Turn off cell phone During class, laptops are for taking notes, not for reading mail, chatting, web surfing, etc. While you’re here, make it worth your while. Pay attention. In return, class will be interesting enough to hold your attention! (I hope…) 26

Introduction to Netlogo

“Pre-homework” assignment: –Download Netlogo and Users Manual (You don’t have to print the manual) –Try out some of the models in the Models Library –Try to modify programs we wrote today (file will be on the class web page) You don’t need to turn in anything for this. Homework 1 assignment will be handed out on Wednesday.