66 research outputs found
I\u27ll Be Back Home In Indiana : In The Morning
https://digitalcommons.library.umaine.edu/mmb-vp/5187/thumbnail.jp
Demand and Congestion in Multiplex Transportation Networks
Urban transportation systems are multimodal, sociotechnical systems; however, while their multimodal aspect has received extensive attention in recent literature on multiplex networks, their sociotechnical aspect has been largely neglected. We present the first study of an urban transportation system using multiplex network analysis and validated Origin-Destination travel demand, with Riyadh’s planned metro as a case study. We develop methods for analyzing the impact of additional transportation layers on existing dynamics, and show that demand structure plays key quantitative and qualitative roles. There exist fundamental geometrical limits to the metro’s impact on traffic dynamics, and the bulk of environmental accrue at metro speeds only slightly faster than those planned. We develop a simple model for informing the use of additional, “feeder” layers to maximize reductions in global congestion. Our techniques are computationally practical, easily extensible to arbitrary transportation layers with complex transfer logic, and implementable in open-source software
Emergence of polarization in a sigmoidal bounded-confidence model of opinion dynamics
We study a nonlinear bounded-confidence model (BCM) of continuous-time
opinion dynamics on networks with both persuadable individuals and zealots. The
model is parameterized by a scalar , which controls the steepness of a
smooth influence function. This influence function encodes the relative weights
that nodes place on the opinions of other nodes. When , this
influence function recovers Taylor's averaging model; when , the influence function converges to that of a modified
Hegselmann--Krause (HK) BCM. Unlike the classical HK model, however, our
sigmoidal bounded-confidence model (SBCM) is smooth for any finite . We
show that the set of steady states of our SBCM is qualitatively similar to that
of the Taylor model when is small and that the set of steady states
approaches a subset of the set of steady states of a modified HK model as
. For several special graph topologies, we give
analytical descriptions of important features of the space of steady states. A
notable result is a closed-form relationship between the stability of a
polarized state and the graph topology in a simple model of echo chambers in
social networks. Because the influence function of our BCM is smooth, we are
able to study it with linear stability analysis, which is difficult to employ
with the usual discontinuous influence functions in BCMs.Comment: 29 pages, 7 figure
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