35,448 research outputs found
Estimating the functional form of road traffic maturity
It has been observed that older high traffic motorways experience lower traffic growth than newer ones (ceteris paribus). This phenomenon is known as traffic maturity; however, it is not captured through traditional time-series long-term forecasts, due to constant elasticity to gross domestic product these models assume. In this paper we argue that traffic maturity results from decreasing marginal utility of transport. The elasticity of individual mobility with respect to the revenue tends to decrease when the level of mobility increases. In order to find evidences of decreasing elasticity we analyse a cross-section time-series sample including 40 French motorways' sections. This analysis shows that decreasing elasticity can be observed in the long term. We then propose a decreasing function for the traffic elasticity with respect to the economic growth, which depends on the traffic level on the road. This model provides a good explanation for the observed traffic evolution and gives a rigorous econometric approach to time-series traffic forecasts.Demand forecast ; Elasticity ; Traffic growth ; Traffic maturity
Approval voting and the Poisson-Myerson environment
Dans ce papier, de nouveaux résultats sont fournis dans le modèle de Poisson-Myerson. Ces résultats se révèlent utiles pour l'étude du vote par assentiment. En effet, le Théorème d'Equivalence des Magnitudes (MET) réduit fortement la complexité du calcul des magnitudes des pivots. Un exemple est fourni qui contraste avec les résultats de Laslier (2004) sur le vote par assentiment. Dans une situation de vote avec trois candidats, le gagnant de l'élection ne coïncide pas avec le gagnant de Condorcet du profil à l'équilibre. Une discussion sur la stabilité de l'équilibre est fournie.
Sincere Scoring Rules
Approval Voting is shown to be the unique scoring rule that leads strategic voters to sincere behavior of three candidates elections in Poisson Games. However, Approval Voting can lead to insincere behavior in elections with more than three candidates.Sincerity, Approval Voting, Scoring rules, Poisson Games
Rotating Scalar Field Wormhole
We derive an exact solution to the Einstein's equations with a stress-energy
tensor corresponding to an opposite-sign scalar field, and show that such a
solution describes the internal region of a rotating wormhole. We also derive
an static wormhole asymptotically flat solution and match them on both regions,
thus obtaining an analytic solution for the complete space-time. We explore
some of the features of these solutions.Comment: Sign of the exponential in equation (10) has been changed. Some typos
correcte
Aspects of the free field description of string theory on AdS_3
The near boundary limit of string theory in AdS_3 is analysed using the
Wakimoto free field representation of SL(2,R). The theory is considered as a
direct product of the SL(2,R)/U(1) coset and a free boson. Correlation
functions are constructed generalizing to the non-compact case the integral
representation of conformal blocks introduced by Dotsenko in the compact SU(2)
CFT. Sectors of the theory obtained by spectral flow manifestly appear. The
formalism naturally leads to consider scattering processes violating winding
number conservation. The consistency of the procedure is verified in the
factorization limit.Comment: 25 pages, typos corrected, references added, to appear in JHE
Our Vulnerable Teenagers: Their Victimization, Its Consequences, and Directions for Prevention and Intervention
Teenagers are twice as likely as any other age group to be victims of violent crime, and one in five teenagers report being the victim of a violent crime, according to a new report. The single greatest factor in predicting criminal behavior on the part of teenagers, the report also found, was not teenage pregnancy, drug use, or truancy, but whether they had been a victim of crime. This publication provides a new and comprehensive analysis of existing -- but largely unnoticed -- research and data on the crime experiences of American teenagers ages 12-19, who make up about 14 percent of the general population, but represent 25 percent of victims of violent crime
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