Search results for "72"

Optimizing the level of service quality of a bike-sharing system

2016

Public bike-sharing programs have been deployed in hundreds of cities worldwide, improving mobility in a socially equitable and environmentally sustainable way. However, the quality of the service is drastically affected by imbalances in the distribution of bicycles among stations. We address this problem in two stages. First, we estimate the unsatisfied demand (lack of free lockers or lack of bicycles) at each station for a given time period in the future and for each possible number of bicycles at the beginning of the period. In a second stage, we use these estimates to guide our redistribution algorithms. Computational results using real data from the bike-sharing system in Palma de Mall…

Review: monoclinic zirconia, its surface sites and their interaction with carbon monoxide

2015

This review concerns monoclinic zirconia, its surface sites and their probing with carbon monoxide. The surface sites and their modifications using thermal treatments with vacuum or reactive gases are also included. In this work, we present information on the nature and manipulation of hydroxyl species and their quantities on the surface, the different types of cationic sites where CO is adsorbed linearly and their energetics, as well as the surface sites and dynamics of formate formation. We also compare the surface concentrations of the different surface species to better understand the extent and nature of the interactions. Finally, we discuss some of the remaining open questions and how…

Correction to: A new approach to modelling the input–output structure of regional economies using non‑survey methods

2021

Pilot study on the combination of an organophosphate-based insecticide paint and pyrethroid-treated long lasting nets against pyrethroid resistant ma…

2015

International audience; A pilot study to test the efficacy of combining an organophosphate-based insecticide paint and pyrethroid-treated Long Lasting Insecticide Treated Nets (LLINs) against pyrethroid-resistant malaria vector mosquitoes was performed in a real village setting in Burkina Faso. Paint Inesfly 5A IGR™, comprised of two organophosphates (OPs) and an Insect Growth Regulator (IGR), was tested in combination with pyrethroid-treated LLINs. Efficacy was assessed in terms of mortality for 12 months using Early Morning Collections of malaria vectors and 30-minute WHO bioassays. Resistance to pyrethroids and OPs was assessed by detecting the frequency of L1014F and L1014S kdr mutation…

The periodic reporting procedure of the United Nations System and the human right to water: opportunities and challenges

2020

A água é fundamental para a vida. Contudo, foi apenas nos anos 70 que o acesso a este bem começou a ser discutido, a nível internacional, como um direito humano. Antes disso, algumas Convenções e Tratados das Nações Unidas reconheciam, de alguma forma, o direito à água, mas tal direito tinha que ser inferido de outros direitos ou estava limitado à uma determinada categoria de pessoas. Independentemente das suas limitações, estes textos podem reforçar a aplicação do direito humano à água, especialmente através dos seus mecanismos de monitoramento: os relatórios periódicos e os casos litigiosos. Assim, o objetivo deste artigo é analisar em que medida o mecanismo de relatórios periódicos pode …

A global model for the estimation of transport costs

2019

This paper presents a model of transport cost determinants that corrects the specification problems observed in the transport cost equations in previous literature. The model includes freight transport supply and demand, as well as infrastructure quality and non-time-varying fixed effects related to the route, the exporting company, its strategy and the product. In addition, when defining the origin-destination routes, the model more appropriately accounts for economies of network and economies of scale. In order to build the database, 583 personal interviews were conducted over the course of 2011 with producing companies that ship goods and with the logistics operators. As a result, 305 ro…

"La incógnita Llanos". Recuperando el arte de Hernando de Llanos a través de su Virgen con el niño y dos ángeles de la Colección Laia Bosch

2011

The assignment of powers in an open-ended European Union

2003

Presented at CESIFO Conference “A Constitution for the EU”, February 2003; International audience; A major characteristic of the European Union is its transitional or evolving nature, in particular with regard to the assignment of powers between the two main levels of government. More precisely, under current constitutional arrangements, this evolving nature takes the form of an integration process which tends to be monotonous, that is, which can only with great difficulty be reversed. The paper is mainly devoted to the explanation of how this comes about and what effects this has on other features of the process. As a concluding remark, however, it suggests that an additional criterion for…

Horizontal competition in multilevel governmental settings

2013

28 pages; Governments situated on the same level of a multi-level governmental system compete with each other as well as with governments placed higher or lower. This paper is concerned with horizontal competition only. It discusses both competition based on the mobility of agents and competition based on comparisons of performance across jurisdictions - i.e., yardstick competition. With regard to the first kind, the focus is on the capacity of governments and voters to decide policies in spite of the mobility of agents. Some attention is also given to non-standard mechanisms in which mobility is manipulated so as to change the structure of the electorate. The paper considers two forms of h…

How significant is yardstick competition among governments? Three reasons to dig deeper

2013

22 pages; The significance of yardstick competition among governments is now confirmed with regard to fiscal variables. This is an important result but the significance of the mechanism must also be sought in a context broader than that of fiscal federalism and without limitation to relations and processes fully observable. Three points are made. Even in the case of governments trying to mimic each other over a single variable, additional variables are involved in an important way. Yardstick competition can be latent without being ineffective. Its major effect, then, is to set bounds to the choices that office-holders could think of making. Finally, the mechanism is a hidden albeit essentia…