3,169 research outputs found
Effectiveness of Variable Message Signs Using Empirical Loop Detector Data
The effectiveness of Variable Messages Signs (VMS) on route guidance is assessed by a discrete probit choice model that estimates the proportion of vehicles that diverts to an alternative routes given the characteristics of different messages. A before–and–after study is also conducted to quantitatively evaluate the network wide reduction of travel time and total delay of VMS systems. We find that VMS has no obvious effect on reduction of travel time, but can reduce the total delay.Route Choice, Diversion Behavior, Cost Benefit Analysis
Design and fabrication of robust broadband extreme ultraviolet multilayers
The random layer thickness variations can induce a great deformation of the
experimental reflection of broadband extreme ultraviolet multilayer. In order
to reduce this influence of random layer thickness fluctuations, the
multiobjective genetic algorithm has been improved and used in the robust
design of multilayer with a broad angular bandpass. The robust multilayer with
a lower sensitivity to random thickness errors have been obtained and the
corresponding multilayer mirrors were fabricated. The experimental results of
robust Mo/Si multilayer with a wide angular band were presented and analyzed,
and the advantage of robust multilayer design was demonstrated
Non-Abelian vortices in the emergent U(2) gauge theory of the Hubbard model
By the spin-fermion formula, the Hubbard model on the honeycomb lattice is
represented by a U(2) gauge theory in the mean field method, non-Abelian vortex
solutions are constructed based on this theory. The quantization condition
shows that the magnetic flux quanta are half-integer. There are bosonic
zero modes for winding vortices. For the fermions, there are 2 zero energy
states (ZESs) corresponding to the single elementary vortex. In the vortex core
and on the edge, the system are in the semi-metal phase with a spin gap and in
the insulator phase with N\'eel order phase, and can be mapped to the
superconductor in class A and CI, respectively.Comment: 4pages, 2table
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