H infinity observer for time-delay systems. Application to FDI for irrigation canals

This paper deals with the problem of fault detection and isolation for time-varying delayed systems. It consists to develop a $H_{\infty}$ observer that generates residuals sensitive to some faults and insensitive to others in order to detect and isolate actuator faults which can occur on the regulation gates of an irrigation canal. The observer design uses a simplified approximate model of the Saint-Venant equations and is formulated with delay-dependent Linear Matrix Inequality (LMI). Simulations done with a realistic model of a real canal show the effectiveness of the metho

A Particle-based Multiscale Solver for Compressible Liquid-Vapor Flow

To describe complex flow systems accurately, it is in many cases important to account for the properties of fluid flows on a microscopic scale. In this work, we focus on the description of liquid-vapor flow with a sharp interface between the phases. The local phase dynamics at the interface can be interpreted as a Riemann problem for which we develop a multiscale solver in the spirit of the heterogeneous multiscale method, using a particle-based microscale model to augment the macroscopic two-phase flow system. The application of a microscale model makes it possible to use the intrinsic properties of the fluid at the microscale, instead of formulating (ad-hoc) constitutive relations

Equilibrium configurations from gravitational collapse

We develop here a new procedure within Einstein's theory of gravity to generate equilibrium configurations that result as the final state of gravitational collapse from regular initial conditions. As a simplification, we assume that the collapsing fluid is supported only by tangential pressure. We show that the equilibrium geometries generated by this method form a subset of static solutions to the Einstein equations, and that they can either be regular or develop a naked singularity at the center. When a singularity is present, there are key differences in the properties of stable circular orbits relative to those around a Schwarzschild black hole with the same mass. Therefore, if an accretion disk is present around such a naked singularity it could be observationally distinguished from a disk around a black hole.Comment: 13 pages, 3 figure. Replaced with published version, several changes made according to referee's advis

Exploring synergies between human rights and public health ethics: A whole greater than the sum of its parts

<p>Abstract</p> <p>Background</p> <p>The fields of human rights and public health ethics are each concerned with promoting health and elucidating norms for action. To date, however, little has been written about the contribution that these two justificatory frameworks can make together. This article explores how a combined approach may make a more comprehensive contribution to resolving normative health issues and to advancing a normative framework for global health action than either approach made alone. We explore this synergy by first providing overviews of public health ethics and of international human rights law relevant to health and, second, by articulating complementarities between human rights and public health ethics.</p> <p>Discussion</p> <p>We argue that public health ethics can contribute to human rights by: (a) reinforcing the normative claims of international human rights law, (b) strengthening advocacy for human rights, and (c) bridging the divide between public health practitioners and human rights advocates in certain contemporary health domains. We then discuss how human rights can contribute to public health ethics by contributing to discourses on the determinants of health through: (a) definitions of the right to health and the notion of the indivisibility of rights, (b) emphasis on the duties of states to progressively realize the health of citizens, and (c) recognition of the protection of human rights as itself a determinant of health. We also discuss the role that human rights can play for the emergent field of public health ethics by refocusing attention on the health and illness on marginalized individuals and populations.</p> <p>Summary</p> <p>Actors within the fields of public health, ethics and human rights can gain analytic tools by embracing the untapped potential for collaboration inherent in such a combined approach.</p

Between history and values: A study on the nature of interpretation in international law

My thesis discusses the place of evaluative judgements in the interpretation of general international law. It concentrates on two questions. First, whether it is possible to interpret international legal practices without making an evaluative judgement about the point or value that provides the best justification of these practices. Second, whether the use of evaluative judgements in international legal interpretation threatens to undermine the objectivity of international law, the neutrality of international lawyers or the consensual and voluntary basis of the international legal system. I answer both questions in the negative. As regards the first, I argue that international legal practice has an interpretive structure, which combines appeals to the history of international practice with appeals to the principles and values that these practices are best understood as promoting. This interpretive structure is apparent not only in the claims of international lawyers about particular rules of international law (here I use the rule of estoppel as an example) but also in the most basic intuitions of international theorists about the theory and sources of general international law. I then argue that some popular concerns to the effect that the exercise of evaluation in the interpretation of international law will undermine the coherence or the usefulness of the discipline are generally unwarranted. The fact that international legal practice has an interpretive structure does not entail that propositions of international law are only subjectively true, that the interpreter enjoys license to manipulate their meaning for self-serving purposes, or that international law will collapse under the weight of irresolvable disagreements, divisions and conflicts about its proper interpretation

Conception d'oservateurs à entrées inconnues pour des systèmes à retards. Application à un canal à surface libre

This paper deals with the problem of full-order observers design for linear continuous delayed state and inputs systems with unknown input (UI) and time-varying delays. A method to design an Unknown Input Observer (UIO) for such systems is proposed based on a delay-dependent stability conditions of the state estimation error system. A Fault Detection and Isolation (FDI) scheme using a bank of such UIO, is also presented and tested on a (FDI) problem related to irrigation canal

Application de la réconciliation de données à un canal d'irrigation

This paper deals with the problem of fault detection and isolation for irrigation canals. We develop two data reconciliation (DR) methods for the validation of measurements, detection and isolation of sensors faults and reconstruction of missing data: first a static data reconciliation is developed for a hydraulic cross-structure of an irrigation canal, then a dynamic data reconciliation method is applied to take account of measurements at the upstream and downstream end of each pool. The methods are evaluated on realistic measurements from an irrigation canal located in the South of France