Dispersion Relation of a Ferrofluid Layer of Any Thickness and Viscosity in a Normal Magnetic Field; Asymptotic Regimes

We have calculated the general dispersion relationship for surface waves on a ferrofluid layer of any thickness and viscosity, under the influence of a uniform vertical magnetic field. The amplification of these waves can induce an instability called peaks instability (Rosensweig instability). The expression of the dispersion relationship requires that the critical magnetic field and the critical wavenumber of the instability depend on the thickness of the ferrofluid layer. The dispersion relationship has been simplified into four asymptotic regimes: thick or thin layer and viscous or inertial behaviour. The corresponding critical values are presented. We show that a typical parameter of the ferrofluid enables one to know in which regime, viscous or inertial, the ferrofluid will be near the onset of instability.Comment: 21 pages, 6 eps figures, Latex, to be published in Journal de Physique I

Market-Based Aid and Economic Reform

This study examines the empirical links between market-based aid and economic reform in sub-Sahara Africa. My research question: Is market-based aid necessary for economic reform across sub-Sahara Africa? To answer that question, I applied both quantitative and qualitative approaches. Specifically, regression analyses were conducted to determine whether or not causality could be established between my dependent and independent variables. 22 sub-Saharan states were used. In addition, two case studies (Ghana and Senegal) were conducted to help explain some of the cultural nuances that may be missing from the statistical analysis. As a result of the Washington Consensus, International Financial Institutions (IFIs) and advanced economies have advocated for economic reforms -- namely macro-level neoliberal structural adjustments - to help facilitate sustainable economic growth and development across emerging economies. This approach has been critiqued in the past since it uses a \u27one-size-fits-all\u27 approach and assumes that since similar reform efforts were successful in the west, then they should work in the sub-Sahara region absent of accounting for internal nuances such as cultural and traditional values, customs, structures and conditions. I argue that more market-based aid could be the best way forward, especially if economic reform efforts are tailored toward four key conduits that are essential for driving subsequent economic growth and development: government capacity, economic freedom, private sector investments, and domestic savings. I hypothesized the aforementioned are positively linked with market-based aid

Aprendizagem Gerencial Construtivista: O Caso de Supervisão em Estágios Acadêmicos

Neste texto, procura-se especular teoricamente a possibilidade de criação de uma pedagogia gerencial ancorada nos fundamentos da pedagogia freireana. O norteamento do texto se dá no pressuposto de que a aprendizagem gerencial deve levar em conta toda a multidimensionalidade do ser humano. O gerente humanista deve ser capaz de complementar a sua aprendizagem formal no seu ambiente de prática por meio da ação e da reflexão. Acredita-se que a aprendizagem é um processo inacabado e infinito. Finaliza-se o ensaio com a convicção de que aprender é o ponto de partida e o ponto de chegada no processo de tornarse um ser humano mais humano e mais flexível

A Formal Proof of Square Root and Division Elimination in Embedded Programs

International audienceThe use of real numbers in a program can introduce differences between the expected and the actual behavior of the program, due to the finite representation of these numbers. Therefore, one may want to define programs using real numbers such that this difference vanishes. This paper defines a program transformation for a certain class of programs that improves the accuracy of the computations on real number representations by removing the square root and division operations from the original program in order to enable exact computation with addition, multiplication and subtraction. This transformation is meant to be used on embedded systems, therefore the produced programs have to respect constraints relative to this kind of code. In order to ensure that the transformation is correct, i.e. preserves the semantics, we also aim at specifying and proving this transformation using the Pvs proof assistant

Elimination des racines et divisions pour du code embarqué

National audienceCe poster présente une transformation de programme qui élimine les divisions et les racines carrées dans des programmes sans boucles. Cette élimination permet de calculer ensuite exactement avec les opérations restante

Improving Evacuation Maps by Integrating Needs and Preferences of End-Users in GIS

International audienceAn efficient communication requires knowing the characteristics of the receiver. Even if this rule of communication is the basis in many fields of applications (marketing, education, advertising …), it is still not operationnaly integrated into flood risk cartographic communication. This is surprising since cartographic software and Geographical Information Systems (GIS) have become inevitable in territorial management and engineering assessments and allow the mappers to produce target-oriented communication resources such as maps in an effective and efficient manner. In our contribution we will show how flood evacuation maps may be produced by integrating the needs with respect to stakeholder communication as well as the preferences of different end-users

Gestão Centrada No Ser Humano: O Caso de dois Coordenadores de Cursos de IES de Foz do Iguaçu

No artigo analisa-se a mudança de paradigma que ocorreu no gerenciamento a partir do desenvolvimento da teoria dos sistemas abertos. Caracteriza-se e analisa-se, também, de maneira comparativa o estilo tradicional de gerenciamento baseado no modelo Estratégia- Estrutura-Sistemas, orientado para tarefas com o estilo gerencial baseado no modelo Objetivos-Processos-Pessoas, orientado para pessoas. Descreve-se e analisa-se a evolução do conceito de organização na era industrial. Enfatiza-se a importância da compreensão de que se vive numa sociedade de organizações. Descreve-se a importância das organizações como mecanismo de crescimento econômico e de controle social. Finaliza-se o texto enfatizando a importância do ser humano para se atingir resultados organizacionais na chamada sociedade do conhecimento

A Temporal Map in Geostationary Orbit: The Cover Etching on the EchoStar XVI Artifact

Geostationary satellites are unique among orbital spacecraft in that they experience no appreciable atmospheric drag. After concluding their respective missions, geostationary spacecraft remain in orbit virtually in perpetuity. As such, they represent some of human civilization's longest lasting artifacts. With this in mind, the EchoStar XVI satellite, to be launched in fall 2012, will play host to a time capsule intended as a message for the deep future. Inspired in part by the Pioneer Plaque and Voyager Golden Records, the EchoStar XVI Artifact is a pair of gold-plated aluminum jackets housing a small silicon disc containing one hundred photographs. The Cover Etching, the subject of this paper, is etched onto one of the two jackets. It is a temporal map consisting of a star chart, pulsar timings, and other information describing the epoch from which EchoStar XVI came. The pulsar sample consists of 13 rapidly rotating objects, 5 of which are especially stable, having spin periods < 10 ms and extremely small spindown rates. In this paper, we discuss our approach to the time map etched onto the cover and the scientific data shown on it; and we speculate on the uses that future scientists may have for its data. The other portions of the EchoStar XVI Artifact will be discussed elsewhere.Comment: Accepted for publication in Astronomical Journa