Energy Optimization based on the Redundancy in WSNs

International audienceAlmost all WSNs (Wireless Sensor Networks) are deployed with some redundancy degree and redundancy is used only for robustness objectives. If not handled in an intelligent way, redundancy results in energy wasting because of (often unnecessary) redundant transmission and reception operations. We propose to take benefit from measurement redundancy to optimize the energy consumption and improve the end-to-end delay. We propose MR-LEACH (Measurement Redundancy aware LEACH) protocol, which is an extension to the well-known LEACH protocol to improve energy consumption in cluster-based WSNs. In addition to cluster formation according to LEACH protocol redundant nodes are grouped taking into account their redundancy and only a single node transmits data in each redundant group. This technique significantly improves the energy consumption and ensures a better end-to-end delay. Through intensive simulations, we discuss the performance of our approach and show how it outperforms the original LEACH protocol in terms of network lifetime and end-to-end delay

A Survey of Fast Scalar Multiplication on Elliptic Curve Cryptography for Lightweight Embedded Devices

Elliptic curve cryptography (ECC) is one of the most famous asymmetric cryptographic schemes which offers the same level of security with much shorter keys than the other widely used asymmetric cryptographic algorithm, Rivest, Shamir, and Adleman (RSA). In ECC, the main and most heavily used operation is the scalar multiplication kP, where the scalar value k is a private integer and must be secured. Various methods for fast scalar multiplication are based on the binary/ternary representation of the scalar. In this chapter, we present various methods to make fast scalar multiplication on ECC over prime field for lightweight embedded devices like wireless sensor network (WSN) and Internet of Things (IoT)

Fast Scalar Multiplication on Elliptic Curve Cryptography in Selected Intervals Suitable For Wireless Sensor Networks

International audienceIn Wireless Sensor Networks (WSNs), providing a robust security mechanism with limited energy resources is very challenging because of sensor node's limited resources (computation, bandwidth, memory). Asymmetric-key can fulfill the requirement, but if the number of nodes is large, symmetric-key cryptography is the best natural method because of its scalability. Asymmetric-key cryptography is power-hungry; nevertheless, Elliptic Curve Cryptosystems (ECC) are feasible and more flexible for sensor nodes. Scalar multiplication is the most widely used operation on ECC. Various methods for fast scalar multiplication exist, but they are based on the binary/ternary representation of the scalar. In this paper, we present a novel technique to make fast scalar multiplication on Elliptic Curve Cryptosystems over prime field for light-weight embedded devices like sensor nodes. Our method significantly reduces the computation of scalar multiplication by an equivalent representation of points based on point order in a given interval. Since our technique can act as a support for most existing methods, after an analytical and efficiency analysis, we implement and evaluate its performance in different scenari

Portée Et Impact De La Dérivé Sur Les Arthroodes Des Principaux Produits Phytosanitaires Utilises Des Cultures Maraichères Des Niayes Du Sénégal

Abstract:In the northern fringe of the Louga region, when plant protection products are sprayed, a relatively large proportion may be lost to the environment. This could have harmful consequences for the health of operators and biodiversity. The aim is to assess and measure the range of droplets from plant protection product drift treatments in relation to climatic conditions, as well as their impact on health and arthropods. The study is being conducted through a survey of 122 market gardeners and on-farm experimentation.As a result, 81% of the growers surveyed had very clear ideas about the problems associated with spray drift. 67% of growers estimated that 10% of the spray liquid used during spraying ended up in the untreated zone. The study also showed that the potential drift distance applied to the tomato crop with the use of a manual backpack sprayer is 6.875 m. The differences between the arthropods found before and after treatment ranged from 1 to 27 individuals per 0.5 m collection point within the first five metres of drift.In conclusion, knowledge of drift and its extent is very important information in the prevention or reduction the negative impact of the use of plant protection product

On the consistency of Sobol indices with respect to stochastic ordering of model parameters.

International audienceIn the past decade, Sobol's variance decomposition have been used as a tool - among others - in risk management. We show some links between global sensitivity analysis and stochastic ordering theories. This gives an argument in favor of using Sobol's indices in uncertainty quantification, as one indicator among others

Profil De L’asthmatique Admis Au Centre Hospitalier National Universitaire De Fann (CHNU) A Dakar (Senegal)

Au Sénégal, la prévalence de l’asthme n’est pas encore évaluée. Les caractéristiques sociodémographiques, épidémiologiques et la provenance des patients asthmatiques consultés au Centre Hospitalier National Universitaire (CHNU) de Fann demeurent peu connues. Cet article contribue à la connaissance du profil des patients asthmatiques admis au CHNU. Il s’est agi d’une étude rétrospective, prospective et transversale à avisée analytique associant l’approche quantitative et qualitative qui s’est déroulée de janvier 1999 à août 2017 à la clinique de pneumologie du CHNU. La population d’étude était constituée des asthmatiques reçus en consultation. Les paramètres analysés concernent les caractéristiques de la population étudiée (âge, sexe, profession et statut matrimonial). Au total 296 patients asthmatiques, soit 36,5% d’hommes contre 63,5% de femmes, ont été enregistrés avec un âge médian qui était de 35 ans. 234 répondants à la variable catégorie socioprofessionnelle, étaient composés de ménagères (24,8%), d’élèves et d’étudiants (20,1%), de commerçants (17,5%), de bureaucrates (6,8%), de personnel de santé (6%) et d’enseignants et de maîtres coraniques (3,8%). A cela s’ajoutait, des ouvriers (3,8%), des couturiers (3,4%), des coiffeurs (3%), des chauffeurs (2,6%), des agriculteurs et éleveurs (2,6%), des mécaniciens et garagistes (1,3%), des pêcheurs et marins (1,3%), des restaurateurs et restauratrices (1,3%) et d’autres (1,7%). Selon le statut matrimonial, 54,3% étaient des mariés, 42,7% de célibataires et 3% de divorcés. Parmi les 296 asthmatiques, 250 résidaient en milieu urbain dakarois. Les antécédents se résumaient sur les signes et les symptômes des patients avec de la toux (34%), de la dyspnée expiratoire nocturne (34%), des expectorations nummulaires (18%) et des crises d’asthme (14%). Le profil des patients asthmatiques présente une population jeune avec une prédominance féminine. In Senegal, the prevalence of asthma has not yet been assessed. The socio-demographic, epidemiological and provenance characteristics of asthmatic patients consulted at the National Hospital University Center (CHNU) remain little known. This article contributes to the knowledge of the profile of asthmatic patients admitted to the CHNU. This was a retrospective, prospective and cross-sectional, analytical wise study combining the quantitative and qualitative approach which took place from January 1999 to august 2017 at the CHNU pulmonology clinic. The study of asthmatics received in consultation. The parameters analyzed relate to the characteristics of the population studied (age, sex, profession and marital status). A total of 296 asthmatic patients, or 36.5% male versus 63.5% female, were registered with a median age of 35 years. 234 respondents to the socio-professional category variable, were made up of housewives (24.8%), pupils and students (20.1%), traders (17.5%), bureaucrats (6.8%), health personnel (6%) and koranic teachers and teachers (3.8%). In addition, workers (3.8%), dressmakers (3.4%), hairdressers (3%), drivers (2.6%), farmers and ranchers (2.6%), mechanics and mechanics (1.3%), fishermen and sailors (1.3%), restaurateurs and restorers (1.3%), and others (1.7%). According to marital status, 54.3% were married, 42.7% were single and 3% were divorced. Among the 296 asthmatics, 250 resided in an urban Dakar environment. The history was summarized by the signs and symptoms of patients with cough (34%), nocturnal expiratory dyspnea (34%), sputum (18%) and asthma attacks (14%). The profile of asthmatic patients presents a young population with a female predominance

Vers une structuration auto-stabilisante des réseaux Ad Hoc

International audienceIn this paper, we present a self-stabilizing asynchronous distributed clustering algorithm that builds non-overlapping k-hops clusters. Our approach does not require any initialization. It is based only on information from neighboring nodes with periodic messages exchange. Starting from an arbitrary configuration, the network converges to a stable state after a finite number of steps. Firstly, we prove that the stabilization is reached after at most n+2 transitions and requires (u+1)* log(2n+k+3) bits per node, whereΔu represents node's degree, n is the number of network nodes and k represents the maximum hops number. Secondly, using OMNet++ simulator, we performed an evaluation of our proposed algorithm.Dans cet article, nous proposons un algorithme de structuration auto-stabilisant, distribuéet asynchrone qui construit des clusters de diamètre au plus 2k. Notre approche ne nécessite aucuneinitialisation. Elle se fonde uniquement sur l’information provenant des noeuds voisins à l’aided’échanges de messages. Partant d’une configuration quelconque, le réseau converge vers un étatstable après un nombre fini d’étapes. Nous montrons par preuve formelle que pour un réseau de nnoeuds, la stabilisation est atteinte en au plus n + 2 transitions. De plus, l’algorithme nécessite uneoccupation mémoire de (u + 1) log(2n + k + 3) bits pour chaque noeud u où u représente ledegré (nombre de voisins) de u et k la distance maximale dans les clusters. Afin de consolider lesrésultats théoriques obtenus, nous avons effectué une campagne de simulation sous OMNeT++ pourévaluer la performance de notre solution

Meeting the sexual health needs of men who have sex with men in Senegal

A study conducted in Dakar, Senegal by researchers from the National AIDS Council, Cheikh Anta Diop University, and the Horizons program obtained information on the needs, behaviors, knowledge, and attitudes of men who have sex with men (MSM). This study offers important insights into the sexuality of MSM, their vulnerability to STI/HIV, and the role of violence and stigma in their lives. The results also highlight the lack of sexual health services and information available to cover the specific needs of MSM. The results of this study were summarized during a meeting held in April 2001 in Dakar and raised awareness of the importance for public health of developing non-stigmatizing interventions for MSM. The results led to the establishment of an NGO pool to develop and coordinate activities for MSM in Dakar