Road Pricing: Old Beliefs, Present Awareness and Future Research Patterns

The theoretical evolution of academic beliefs and practical policymakers' perceptions of road pricing (from now on rp) as an instrument of efficient and equitable allocation of resources are described and analysed. The aim of the paper is to reconstruct the logical evolution of the theory behind rp in order to understand why there has been scarce policy impact in spite of a long theoretical tradition. In so doing I try to bring to the fore the fundamental issues that will have to be tackled by future research in order to generate consensus around this policy instrument. The paper is structured in four parts. In the first part the fundamental issues of a typical rp model are considered. Among the most important aspects one recalls: first-best/second-best environment, short/long term analysis, homogeneous/heterogeneous time evaluation, perfect/imperfect information, efficiency/equity analysis, use/non-use of resources generated, private/public transportation provision. In the second part the characterising parameters have been interpreted in the light of the Smeed Report of 1964 that can be considered representative of the "old belief". In the third part the "present awareness" is expressed by an analysis of the main contents of the book Internalising the Social Costs of Transport of 1993. In the fourth part some reflections on the most promising research areas for rp implementation and acceptance are put forward. Specific research will have to be conducted concerning social acceptability and feasibility, simultaneous cost internalisation, behavioural assumptions, information and pricing interconnections.Road pricing, Social Acceptability, Congestion, Congestion charging

Entropy solutions for a traffic model with phase transitions

In this paper, we consider the two phases macroscopic traffic model introduced in [P. Goatin, The Aw-Rascle vehicular traffic flow with phase transitions, Mathematical and Computer Modeling 44 (2006) 287-303]. We first apply the wave-front tracking method to prove existence and a priori bounds for weak solutions. Then, in the case the characteristic field corresponding to the free phase is linearly degenerate, we prove that the obtained weak solutions are in fact entropy solutions \`a la Kruzhkov. The case of solutions attaining values at the vacuum is considered. We also present an explicit numerical example to describe some qualitative features of the solutions

Superprocesses as models for information dissemination in the Future Internet

Future Internet will be composed by a tremendous number of potentially interconnected people and devices, offering a variety of services, applications and communication opportunities. In particular, short-range wireless communications, which are available on almost all portable devices, will enable the formation of the largest cloud of interconnected, smart computing devices mankind has ever dreamed about: the Proximate Internet. In this paper, we consider superprocesses, more specifically super Brownian motion, as a suitable mathematical model to analyse a basic problem of information dissemination arising in the context of Proximate Internet. The proposed model provides a promising analytical framework to both study theoretical properties related to the information dissemination process and to devise efficient and reliable simulation schemes for very large systems

The benefits from publicly funded research

Research, Technological change, Government Policy

Eigenvector-Based Centrality Measures for Temporal Networks

Numerous centrality measures have been developed to quantify the importances of nodes in time-independent networks, and many of them can be expressed as the leading eigenvector of some matrix. With the increasing availability of network data that changes in time, it is important to extend such eigenvector-based centrality measures to time-dependent networks. In this paper, we introduce a principled generalization of network centrality measures that is valid for any eigenvector-based centrality. We consider a temporal network with N nodes as a sequence of T layers that describe the network during different time windows, and we couple centrality matrices for the layers into a supra-centrality matrix of size NTxNT whose dominant eigenvector gives the centrality of each node i at each time t. We refer to this eigenvector and its components as a joint centrality, as it reflects the importances of both the node i and the time layer t. We also introduce the concepts of marginal and conditional centralities, which facilitate the study of centrality trajectories over time. We find that the strength of coupling between layers is important for determining multiscale properties of centrality, such as localization phenomena and the time scale of centrality changes. In the strong-coupling regime, we derive expressions for time-averaged centralities, which are given by the zeroth-order terms of a singular perturbation expansion. We also study first-order terms to obtain first-order-mover scores, which concisely describe the magnitude of nodes' centrality changes over time. As examples, we apply our method to three empirical temporal networks: the United States Ph.D. exchange in mathematics, costarring relationships among top-billed actors during the Golden Age of Hollywood, and citations of decisions from the United States Supreme Court.Comment: 38 pages, 7 figures, and 5 table

The blob and the block. When the rhetoric of the smooth and the striated went all wrong

This paper conforms to a view of architecture and the distribution of urban space as bio-political parameters of dominance and resistance. Using G. Deleuze & F. Guattari’s seminal essay on 1444. The Smooth and the Striated, I intend to show how Global Capitalism, by replicating the discourse of the smooth and the ungraspable, has voided Dialectics of its subversive potential.El presente artículo contempla la arquitectura y la distribución del espacio urbano como parámetros biopolíticos de dominación y resistencia. Valiéndose del ensayo 1444. Lo liso y lo estriado, de Gilles Deleuze & Felix Guattari, se pretende demostrar cómo el capitalismo global, gracias a su capacidad para emular el discurso de lo fluido y lo intangible, habrá conseguido despojar a lo dialéctico de su potencial subversivo