2,600 research outputs found

    Examining the catalytic effect of aid on domestic resource mobilization for social transfers in low-income countries

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    Social transfers, a non-contributory form of social protection, present a great potential to tackle poverty and inequality, and support inclusive socioeconomic development. Yet, they also represent a long-term financial commitment, and in environments where they are most needed, national policymakers are often reluctant to introduce them. In reaction to this situation, foreign aid actors have been allocating resources to support the expansion of social transfers in low-income countries. Progress in terms of policy uptake has been slow, and there has been concern over the ability of aid initiatives around social transfers to translate into sustainable policy changes and contribute to more inclusive development patterns. Better understanding why governments come to adopt and finance certain types of social transfers - and what role, if any, foreign aid actors play - can usefully inform the formulation of strategies towards the expansion of basic social protection in countries where the process appears to have stalled. This paper is part of the UNRISD research project on "The Politics of Domestic Resource Mobilization for Social Development". Its specific contribution is with regards to the catalytic effect of foreign aid on domestic resource mobilization for social transfers in low-income countries. The paper elaborates on a comparative analysis of the origins and features of six sizable social transfer schemes currently operating in low-income African countries. Findings suggest a catalytic effect of aid on mobilizing additional domestic resources for social transfers. But in light of these findings, the paper questions whether, at least in some cases, a narrow focus on social transfer instruments may have distracted public resources (domestic and foreign) away from deeper causes of poverty and marginalization, doing a disservice to the transformative agenda development partners claim to defend

    Damage location method for thin composites structures - application to an aircraft door

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    Piezoelectric sensors are widely used for Structure Health Monitoring (SHM) technique due to their high-frequency capability. In particular, electromechanical impedance (EMI) techniques give simple and low cost solutions for detecting damage in composite structures. For example, damage indicators computed from EMI deviations between the pristine structure and the damaged structure can be compared to a threshold in order to point damage. When it is question of damage localization, the simple analysis of the electromechanical impedance fails to furnish enough information. We propose a method based both on EMI damage indicators and on the acoustic attenuation level to locate damage. One of the main advantages of our method, so called data driven method, is that only experimental data are used as inputs for our algorithms. It does not rely on any model

    Critical slowing down and fading away of the piston effect in porous media

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    We investigate the critical speeding up of heat equilibration by the piston effect (PE) in a nearly supercritical van der Waals (vdW) fluid confined in a homogeneous porous medium. We perform an asymptotic analysis of the averaged linearized mass, momentum and energy equations to describe the response of the medium to a boundary heat flux. While nearing the critical point (CP), we find two universal crossovers depending on porosity, intrinsic permeability and viscosity. Closer to the CP than the first crossover, a pressure gradient appears in the bulk due to viscous effects, the PE characteristic time scale stops decreasing and tends to a constant. In infinitly long samples the temperature penetration depth is larger than the diffusion one indicating that the PE in porous media is not a finite size effect as it is in pure fluids. Closer to the CP, a second cross over appears which is characterized by a pressure gradient in the thermal boundary layer (BL). Beyond this second crossover, the PE time remains constant, the expansion of the fluid in the BL drops down and the PE ultimately fades away

    Panel of resonators with variable resonance frequency for noise control

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    The article focuses on acoustic resonators made of perforated sheets bonded onto honeycomb cavities. This kind of resonators can be used in adverse conditions such as high temperature, dirt and mechanical constraints. For all these reasons, they are, for example, widely used in aeronautic applications. The acoustic properties are directly linked to the size, shape and porosity of holes and to the thickness of air gaps. Unfortunately, the acoustic absorption of these resonators is selective in frequency and conventional acoustic resonators are only well adapted to tonal noises. In case of variable tonal noise, the efficiency is limited if the resonators are not tunable. One common solution is to control the depth of cavities based on the noise to be attenuated. This article proposes another technology of tunable resonators with only a very small mass and size increase. It consists of two superposed and identically perforated plates associated with cavities. One plate is fixed and bonded to the cavities and the other plate is mobile. The present concept enables to change the internal shapes of the holes of the perforated layers. The article describes this system and gives a theoretical model of the normal incidence acoustic impedance that allows to predict the acoustic behavior, in particular the resonance frequency. The model shows that the resonance frequency varies with hole profiles and that the absorption peak moves towards the lower frequencies. The proposed model is validated by measurements on various configurations of resonators tested in an impedance tube. The perspectives of this work are to adapt the hole profiles using an actuator in order to perform active control of impedance

    Smart EMI monitoring of thin composite structures

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    This paper presents a structural health monitoring (SHM) method for in-situ damage detection and localization in carbon fibre reinforced plates (CFRP). The detection is achieved using the electromechanical impedance (EMI) technique employing piezoelectric transducers as high-frequency modal sensors. Numerical simulations based on the finite element method are carried out so as to simulate more than a hundred damage scenarios. Damage metrics are then used to quantify and detect changes between the electromechanical impedance spectrum of a pristine and damaged structure. The localization process relies on artificial neural networks (ANN) whose inputs are derived from a principal component analysis of the damage metrics. It is shown that the resulting ANN can be used as a tool to predict the in-plane position of a single damage in a laminated composite plate

    Almost PSH Functions on Calabi’s Bundles

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    pp.139-163We give an explicit lower bound for almost psh functions on some Fano manifolds. These manifolds generalize those introduced by Calabi in [5], and also provide a generalization of the concept of the blowing-up of PmC\mathbb P_m\mathbb C at one point. To this end, we use a method introduced in [4], which consists of studying the behavior of psh functions along some well-chosen holomorphic curves

    The "Object-as-a-Service" paradigm

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    International audienceThe increasing interest about the Internet of Things (IoT) is almost as remarkable than its practical absence in our everyday lives. Announced as the new breakthrough in IT industry, the domain is characterized by a large number of architecture propositions that are in charge of providing a structure for applications creation. These architectures are needed because of the heterogeneity of stakeholders involved in IoT Applications. Programming languages, operating systems, hardware specificities, processing power, memory, network organization, characteristics, constraints, the world of IoT is so diverse. Furthermore, these architectures should provide an easy access to users that are not aware of IT technologies involved. The Services Oriented Computing (SOC) has shown in the past its relevance to the decoupling constraints interoperability among stakeholders. The composition of loosely coupled services facilitates the integration of very varied elements and provides agility in the creation of new applications. But unlike the approach inherited from the SOC in pre-existing services are composed to obtain a specific application, we propose a more dynamic notion of service. Our "Object-as-a-Service" point of view is based on the notion of building dynamically the service needed on each Object and then integrate it in the whole composition. This paper focus on the gain of this approach for the IoT by promoting the "Object-as-a-Service" paradigm as a basis for the creation of dynamic and agile user-made applications
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