Fundamental diagrams of vehicular traffic flow are generally multivalued in the congested flow regime. We show that such set-valued fundamental diagrams can be constructed systematically from simple second order macroscopic traffic models, such as the classical Payne-Whitham model or the inhomogeneous Aw-Rascle-Zhang model. These second order models possess nonlinear traveling wave solutions, c...

This article reviews the popular reasons for the belief that dwarf elliptical galaxies and (ordinary) elliptical galaxies are distinct and separate species. They include: light–profile shape (or similarly image concentration); the magnitude–central surface brightness diagram; the magnitude–effective surface brightness diagram (or similarly the magnitude–effective radius diagram); and the Fundam...

Pedestrian facilities are more and more congested. It is important to understand the modeling of pedestrian flows to assure safety and comfort. Many models have already been developed such as the social force modle and PedCTM. The problem is that either they allow for population heterogeneity or they are fast. The goal of this project is to implement a new model that has both of these character...

Pedestrian crowds often have been modeled as many-particle system including microscopic multi-agent simulators. One of the key challenges is to unearth governing principles that can model pedestrian movement, and use them to reproduce paths and behaviors that are frequently observed in human crowds. To that effect, we present a novel crowd simulation algorithm that aims to generate pedestrian t...

0965-8564/$ see front matter 2011 Elsevier Ltd doi:10.1016/j.tra.2011.04.004 ⇑ Corresponding author. Tel.: +41 21 69 32481; fa E-mail address: [email protected] (N. G Observations of traffic pairs of flow vs. density or occupancy for individual locations in freeways or arterials are usually scattered about an underlying curve. Recent observations from empirical data in arterial networ...

We exhibit an algorithm to compute a Dirichlet domain for a Fuchsian group Γ with cofinite area. As a consequence, we compute the invariants of Γ, including an explicit finite presentation for Γ. Let Γ ⊂ PSL2(R) be a Fuchsian group, a discrete group of orientationpreserving isometries of the upper half-plane H with hyperbolic metric d. A fundamental domain for Γ is a closed domain D ⊂ H such th...

Urban rail transit often operates with high service frequencies to serve heavy passenger demand during rush hours. Such operations can be delayed by train congestion, passenger congestion, and the interaction of the two. Delays are problematic for many transit systems, as they become amplified by this interactive feedback. However, there are no tractable models to describe transit systems with ...

The politics and ethics of participatory development have been a topic of vibrant debate since the 1990s. While proponents assert that participation emancipates and empowers marginalized peoples, critics assert that it enacts new forms of control and regulation. This paper reads these debates through the analytical lens offered by assemblage thinking. Assemblage allows us to foreground affectiv...

We exhibit an algorithm to compute a Dirichlet domain for a Fuchsian group Γ with cofinite area. As a consequence, we compute the invariants of Γ, including an explicit finite presentation for Γ. Let Γ ⊂ PSL2(R) be a Fuchsian group, a discrete group of orientationpreserving isometries of the upper half-plane H with hyperbolic metric d. A fundamental domain for Γ is a closed domain D ⊂ H such th...

Cellular automata (CA) rules possessing additive invariants have been studied since early 90’s. The simplest form of an additive invariant is the sum of all site values over a finite lattice with periodic boundary conditions. Rules with such an invariant are known as number-conserving rules, and they exhibit many interesting properties. For example, they can be viewed as systems of interacting ...