Multicriteria Modelling of Irrigation Water Market at Basin Level

This paper develops a multi-criteria methodology to simulate irrigation water markets at basin level. For this purpose it is assumed that irrigators try to optimise personal multi-attribute utility functions via their productive decision making process (crop mix), subject to a set of constraints based upon the structural features of their farms. In this sense, farmers with homogeneous behaviour regarding water use have been grouped, such groups being established as .types. to be considered in the whole water market simulation model. This model calculates the equilibrium through a solution that maximises aggregate welfare, which is quantified as the sum of the multi-attribute utilities reached by each of the participating agents. This methodology has been empirically applied for the Duero Basin (Northern Spain), finding that the implementation of this institution would increase economic efficiency and agricultural labour demand, particularly during droughts.Water markets, Multi-Attribute Utility Theory, Irrigation water, Duero Valley (Spain).

Property Rights Reform and Development: A Critique of the Cross-National Regression Literature

The legal protection of property rights is increasingly viewed as a crucial, if not the crucial, condition for economic growth and pro-poor development. Empirical support is generally based on cross-national correlations between measures of secure property rights and good development outcomes in the long-run. However, whether these associations hold in the short- and medium-run has, to our knowledge, not been studied. In this paper, we evaluate the relationship between the protection of property rights and growth using three property rights indices from the Heritage Foundation, Fraser Institute and World Economic Forum covering the experience of 162 countries between 1995 and 2005. While we find a strong correlation between the level of country property rights protections scores and economic growth, when we evaluate the change and improvement in country ranking scores of property rights, this positive association disappears. These findings could be interpreted as indicating either that there is i) no causal relationship between property rights and growth (at least in the short-run), or that ii) the property rights indices have poor validity.Property rights; Development; Pro-poor

Onset of the Kelvin-Helmholtz instability in partially ionized magnetic flux tubes

Context. Recent observations of solar prominences show the presence of turbulent flows that may be caused by Kelvin-Helmholtz instabilites (KHI). However, the observed flow velocities are below the classical threshold for the onset of KHI in fully ionized plasmas. Aims. We investigate the effect of partial ionization on the onset of KHI in dense and cool cylindrical magnetic flux tubes surrounded by a hotter and lighter environment. Methods. The linearized governing equations of a partially ionized two-fluid plasma are used to describe the behavior of small-amplitude perturbations superimposed on a magnetic tube with longitudinal mass flow. A normal mode analysis is performed to obtain the dispersion relation for linear incompressible waves. We focus on the appearance of unstable solutions and study the dependence of their growth rates on various physical parameters. An analytical approximation of the KHI linear growth rate for slow flows and strong ion-neutral coupling is obtained. An application to solar prominence threads is given. Results. The presence of a neutral component in a plasma may contribute to the onset of the KHI even for sub-Alfv\'enic longitudinal shear flows. Collisions between ions and neutrals reduce the growth rates of the unstable perturbations but cannot completely suppress the instability. Conclusions. Turbulent flows in solar prominences with sub-Alfv\'enic flow velocities may be interpreted as consequences of KHI in partially ionized plasmas.Comment: 8 pages, 4 figures. Accepted for publication in A&

Distributed MPC with time-varying communication network: A density-dependent population games approach

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This work addresses distributed control design by using density-dependent population dynamics. Furthermore, stability of the equilibrium point under this proposed class of population dynamics is studied, and the relationship between the equilibrium point of density-dependent population games (DDPG) and the solution of constrained optimization problems is shown. Finally, a distributed predictive control is designed with the proposed density-dependent dynamics, and contemplating a time-varying communication network.Peer ReviewedPostprint (author's final draft

Constrained distributed optimization : A population dynamics approach

Large-scale network systems involve a large number of states, which makes the design of real-time controllers a challenging task. A distributed controller design allows to reduce computational requirements since tasks are divided into different systems, allowing real-time processing. This paper proposes a novel methodology for solving constrained optimization problems in a distributed way inspired by population dynamics. This methodology consists of an extension of a population dynamics equation and the introduction of a mass dynamics equation. The proposed methodology divides the problem into smaller sub-problems, whose feasible regions vary over time achieving an agreement to solve the global problem. The methodology also guarantees attraction to the feasible region and allows to have few changes in the decision-making design when a network suffers the addition/removal of nodes/edges. Then, distributed controllers are designed with the proposed methodology and applied to the large-scale Barcelona Drinking Water Network (BDWN). Some simulations are presented and discussed in order to illustrate the control performance.Peer ReviewedPostprint (author's final draft

Dynamic impedances of bridge abutments

The soil-structure interaction at bridge abutments may introduce important changes in the dynamic properties of short to medium span bridges. The paper presents the results obtained, through the use of the Boundary Element Method (B.E.M.) technique in several typical situations, including semiinfinite and layered media. Both stiffness and damping properties are included