Background Information: The degree of separation in a network is equal to the average length of the shortest path between pairs of nodes. Extracting the degrees of separation for a large network is computationally demanding. The computation involves averaging the degrees of separation of each individual node in the network. Thus, the time required to […]

In my last blog, I investigated the time taken for a giant component to develop in a social network.In that experiment, when the largest component contained the majority of people in the population, I stopped the simulation and recorded the time taken. If I were to continue the simulation, we’ll observe that the giant component […]

So a classic problem that wasted hours of my life when I was younger:
You have three houses: A, B, and C. Your goal is to connect them to three utilities: Water, Gas, and Electricity (W, G, and E)… but none of the lines can cross. It turns out this is impossible if all 6 nodes […]

In class, we discussed the way “technologies” spread throughout a network via a system of adoption. In the model, nodes adopt a technology if a sufficient fraction of their neighbors has adopted the technology. Although not applied to social networks, the mathematics of models like this has been studied since the 1940s. […]

Thomas Schelling’s segregation model, discussed in class and in his book Micromotives and Macrobehavior, yields pessimism for those who believe in and strive for integrated neighborhoods. Even a mild preference on the part of all residents for neighbors of the same color (Schelling uses 33%, the example in class used 40%) eventually the neighborhood becomes […]

In our class, we have discussed a simplistic model to analyze to the diffusion of new technologies through a network of people. Our model operates in the framework of a coordination game, where we consider the payoffs to a pair of adjacent nodes if they adopt either technology. From these payoffs, a threshold value can […]

Every day we take the benefits from global networks and optimized supply chains for granted. New products become cheaper and more available. Seasonal produce such as strawberries are shipped from around the world and are available year round. Companies can expand their businesses across the globe. Products are assembled leveraging the resources provided by a […]

Information Cascades cause all kinds of problems. Even when every participant acts rationally on his or her own behalf, they very frequently result in socially unfavorable outcomes. However, if a participant is able to recognize the existence of a cascade, acknowledges that it may lead to an unfavorable outcome, and blindly follows suit […]

http://www.nature.com/nature/journal/v451/n7175/full/nature06455.html
http://www.nature.com/nature/journal/v451/n7175/box/nature06455_BX1.html
“The coevolution of choosiness and cooperation” from Nature magazine
http://en.wikipedia.org/wiki/Evolutionarily_stable_strategy
Supplementary Wikipedia article: “Evolutionarily Stable Strategy”
The motivation for analyzing choosiness and cooperation between individuals is to seek a better understanding of biological systems and human societies. The interaction that occurs specifically between non-relatives is what the article focuses on.
The way choosiness and cooperation relate to the […]

The equilibrium-based analysis of traffic routing that we studied earlier in the semester (in connection with Braess’ Paradox) assumes that the traffic delay functions are known in advance by all drivers. Drivers are assumed to be taking the same trip day after day, to experiment with alternative routes, and to develop an instinct about […]