Ajustement structurel et effondrement des modèles idéologiques : Crise et renouveau de l'État africain

The crisis of the State preceded structural adjustment, the latter only exposing a pre-existing economic and financial crisis. As a result of this financial crisis, the State’s ambitions have fallen into discredit. Its leaders are less able to redistribute wealth and, as one problem leads to another, their political survival is threatened. The « revolt of the belly » has been carried over to the political playing-field thanks to favourable international circumstances which have forced states to accept multipartygovernment. From this viewpoint, the collapse of ideological models and the structural policies of adjustment are as much factors in the crisis of the African State as they are in its renewal

Multi phase system for metal disc induction heating: modelling and RMS current control

This paper presents a multi phase induction system modelling for a metal disc heating and further industrial applications such as hot strip mill. An original architecture, with three concentric inductors supplied by three resonant current inverters leads to a reduced element system, without any coupling transformers, phase loop, mobile screens or mobile magnetic cores as it could be found in classical solutions. A simulation model is built, based on simplified equivalent models of electric and thermal phenomena. It takes into account data extracted from Flux2D® finite element software, concerning the energy transfer between the inductor currents and the piece to be heated. It is implemented in a versatile software PSim, initially dedicated to power electronic. An optimization procedure calculates the optimal supply currents in the inverters in order to obtain a desired power density profile in the work piece. The paper deals with The simulated and experimental results are compared in open-loop and closed loop. The paper ends with a current control method which sets RMS inductor currents in continuous and digital conditions

Nonlinear mechanical and poromechanical analyses : comparison with analytical solutions

International audienceThe validation of computational schemes for modelling multiphysic phenomena in porous geomaterials is a key importance in geoenvironmental applications. This paper focuses on the vadiation of nonlinear and coupled hydromechanical schemes by comparing the results of numerical predictions performed with COMSOL and the mathematical solutions. Firstly, we simulate the nonlinear mechanical behaviour of rock mass around a deep cylindrical hole. The second example treats on the simulation of the well-known one-dimensional consolidation of a column of saturated porous rock. Finally a validation of poroelastic calculations based on the drainage of a cylindrical hole in porous media is achieved by comparison to an existing analytical solution

Managing Associated Risks in Cloud Computer Applications

Cloud Computing, the long-held dream of computing as a utility, has the potential to transform a large part of the IT industry, making software even more attractive as a service and shaping the way IT hardware is designed and purchased. Developers with innovative ideas for new Internet services no longer require the large capital outlays in hardware to deploy their service or the human expense to operate it. This paper focuses on an overview of cloud computing as a technology and has chosen the party agent reports of an electoral process as a case study. The case study was used to develop an application which was tested and deployed on a local computer and subsequently deployed on the cloud infrastructure. Java programming language and Google App engine were the tools used to develop and deploy the application. The work demonstrates the benefits of deploying applications using the cloud service over on-premise deployment especially where real time data is needed like reporting incidents during elections. Keywords: Google App Engine, Java Programming Language, cloud infrastructur

A Comparative Performance Analysis of Popular Internet Browsers in Current Web Applications

As more and more services become available on the Internet, the issue of fast and secured access to online resources gains more importance. The growth of the internet has encouraged a high number of people to explore and take advantage of the World Wide Web (www). The window to the World Wide Web is a web browser, hence the development of various web browsers in the market today. A comparative study of four web browsers namely Internet Explorer, Mozilla Firefox, Opera and Netscape was carried out. A web portal developed and fully tested was used to evaluate the performance of the four browsers. The results revealed that Mozilla Firefox and Netscape perform best in down load time, Internet Explorer performs best in memory usage, privacy and security, Mozilla Firefox and Netscape performs best in Page Layout, and Opera performs best in speed and performance. Key words: World Wide Web, Internet Browser, W3C, APIs, Milne

Geophysical Mapping by Electromagnetic Induction of Gold Occurrences in Birimian Formations of Liptako: Case of Sorbon Haoussa Sector (Souhwest Niger)

The survey zone corresponds to the Sirba greenstone belt, one of Liptako Birimian Formations (LBF) of Niger. Previous aeromagnetic and geochemical works reveal the significant gold occurrences. The present study integrates geophysical mapping of these occurrences by electromagnetic induction on field. A multi-frequencies system of 10 frequencies was used for depth and subsurface investigation of resistive anomalies. The interpretation of obtained results shown two types of resistive anomalies, corresponding to the conductive units: deep anomalies obtained with low frequencies and subsurface anomalies detected with high frequencies. The subsurface anomalies were detected around the 15 meters and the deep anomalies were recorded beyond 80 meters. All of the detected resistive anomalies are in a lenticulars shapes oriented N-S or E-W. The analysis of combined resistivity map from all frequencies shown three zones of resistive anomaly presenting a high potential in conductive metals: The first zone Z1 (most important), located in Eastern studied zone covering, covering a surface of 3.5 Km2, the second zone Z2 is located in West and covers an area of 2.9 Km2 and the third anomaly zone Z3 is located in South with a surface of 0.96 Km2. On field, these conductive units correspond to auriferous quartz veins and/or highly altered manganese schists, exploited by using the artisanal mining wells, up to 20 meters in depth

A Framework for Privacy and Hate Speeches Control on Social Media in Mobile Computing

The hype in information technology has led to the use of mobile devices to carry out several activities such as financial transactions, communications, learning and other related activities using the internet. Social networking platforms today are used to facilitate the activities carried out on mobile devices. The use of these social network platforms such as Facebook, Twitter, Whatsapp, Snapchat, Instagram among others on mobile devices is called mobile social network. A mobile social network makes it faster and easier for users to relate to one another and carry out other related activities at convenience. The major challenge with the use of social network applications on mobile devices is that, many illegal activities are carried out such as hate speeches and bigotry statement which has demeaning the interest of users. This research work proposes a technique for discovering and blocking hate speeches and bigotry users on social network platforms using text scanning and matching algorithm; in order to curtail the damages caused to national security and unity by such statement. Keywords: Mobile social network, social network

Collapse/subsidence : role and influence of overburden in Lorraine iron mines case

International audienceThis paper presents several large-scale numerical modellings of valley and tray situations with the presence or not of vertical fractures. Through these modellings, we firstly attempt to evaluate an influence zone, in terms of stress variations induced by the creation of the valley. Next we study more particularly the behaviour of a stiff overburden, according to situations, with the aim to estimate if a valley and/or the presence of subvertical fractures influence the overburden massivity.Ce papier présente plusieurs modélisations à grande échelle d'une situation de vallée et de plateau en présence ou non d'une fracturation verticale. A travers ces modélisations, nous tentons d'évaluer une zone d'influence, en termes de variations de contraintes induites par la création de la vallée. Puis nous étudions plus particulièrement le comportement d'une couverture raide, en fonction des situations, dans l'objectif d'estimer si une vallée et/ou une fracturation subverticale influencent la massivité du recouvremen

Ultrasonic sounding and monitoring of the excavation damaged zone in relation with drift support

International audienceUnder high in situ stresses, the excavation of underground openings generally causes the creation of a disturbed (EdZ: Excavation disturbed Zone) and/or damaged (EDZ: Excavation Damaged Zone) zone, resulting from the initiation and growth of cracks and fractures and from the pre-existing stress redistribution. The EdZ or EDZ changes the mechanical and hydromechanical properties which in return, constitute a potential risk for the performance of the geologic and/or engineered structures in the context of waste underground storage. Ultrasonic experiments have been implemented to characterize the EDZ extension around drifts and its evolution in time according to the structural support type (soft or rigid) and the environmental conditions. Those studies consist of two experimental components: (1) the prior auscultation of the floor and sidewalls of the gallery by ultrasonic transmission tomography, (2) the monitoring of the time-dependant evolution of EDZ and the analysis of measurable changes in the propagation of ultrasonic waves in the medium term. A code for computing these continuous in situ velocity measurements into the elastic has been developed. Then, the five dynamic elastic constants for the assumed transverse isotropic character of the rock are derived as a function of time and the distance from the drift wall. Performed a few months after the excavation of the galleries, the tomography shows that ultrasonic velocities are higher in the orthoradial direction (both in the concrete support and rock). This velocity field highlights clearly the damaged zone and induced stress shift

Processing Radio Astronomical Data Using the PROCESS Software Ecosystem

In this paper we discuss our efforts in "unlocking" the Long Term Archive (LTA) of the LOFAR radio telescope using the software ecosystem developed in the PROCESS project. The LTA is a large (>50 PB) archive that expands with about 7 PB per year by the ingestion of new observations. It consists of coarsely calibrated "visibilities", i.e. correlations between signals from LOFAR stations. Converting these observations into sky maps (images), which are needed for astronomy research, can be challenging due to the data sizes of the observations and the complexity and compute requirements of the software involved. Using the PROCESS software environment and testbed, we enable a simple point-and-click-reduction of LOFAR observations into sky maps for users of this archive. This work was performed as part of the PROCESS project which aims to provide generalizable open source solutions for user friendly exascale data processing