1,212 research outputs found

    On Steering Swarms

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    The main contribution of this paper is a novel method allowing an external observer/controller to steer and guide swarms of identical and indistinguishable agents, in spite of the agents' lack of information on absolute location and orientation. Importantly, this is done via simple global broadcast signals, based on the observed average swarm location, with no need to send control signals to any specific agent in the swarm

    Fertilité des sols agricoles sous vigne et sous blé de la région de Mohammedia-Benslimane (Maroc)

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    L’objectif de ce travail est l’évaluation agronomique de la qualitĂ© du sol sous vigne et sous blĂ© dans la rĂ©gion Mohammedia-Benslimane au Maroc, Ă  travers les indicateurs chimiques de la qualitĂ© du sol (pH, CE, CaCO3, Carbone organique total, Azote, Phosphore et Potassium). Les rĂ©sultats de cette Ă©tude montrent que les valeurs du pH sont neutres Ă  lĂ©gĂšrement acides dans toutes les stations alors que les taux de carbone organique total et d’azote total sont plus Ă©levĂ©s sous blĂ© que sous vigne dans la rĂ©gion de Mohammedia Benslimane. Les valeurs moyennes du phosphore semblent globalement plus importantes dans les parcelles sous vigne (33.62 ppm) que dans les parcelles sous blĂ© (25.51 ppm) et les teneurs moyennes enPotassium sont plus faibles (58,57 ppm) dans les sols vignobles que dans les sols sous blĂ© (63,62 ppm).Mots-clĂ©s : Mohammedia-Benslimane, fertilitĂ©, Carbone organique total, azote, phosphore, potassium

    Etat Environnemental Des Sols De La Region De Casablanca

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    La pollution chimique, dans la rĂ©gion de Casablanca impacte la qualitĂ© des sols agricoles. Cinq sites de la rĂ©gion de Casablanca sont Ă©tudiĂ©s : les sites d’Oued Hassar, Oued Merzeg, Bouskoura, Benslimane-Mohammedia et Bouznika. L’objectif est l’analyse comparative de cinq Ă©lĂ©ments traces mĂ©talliques(Cadmium, Plomb, Cuivre, Zinc et Nickel) des sols afin d’évaluer l’état environnemental et de prĂ©server les potentialitĂ©s et l’innocuitĂ© des sites de la rĂ©gion de Casablanca . Un suivi des variations des paramĂštres physico-chimiques du sol (pH, carbonates de calcium et matiĂšres organiques) est rĂ©alisĂ©, suite Ă  la dĂ©gradation de l’eau d’irrigation par l’utilisation d’eaux usĂ©es, et de l’impact de la pollution chimique. L’étude statistique par le test d’Anova montre des diffĂ©rences significatives concernant les paramĂštres physico-chimiques entre tous les sites. L’analyse des Ă©lĂ©ments traces mĂ©talliques montre que les sols des sites irriguĂ©s par Oued Hassar prĂ©sentent des teneurs en Cadmium de 2,91 ppm et en Plomb de 137,61ppm qui dĂ©passent les normes prĂ©conisĂ©es par l’Organisation Mondiale de la SantĂ© (O.M.S.), respectivement de 2 ppm et 100 ppm. Les teneurs en Cuivre dans les sols des sites irriguĂ©s par l’Oued Merzeg restent les plus Ă©levĂ©es et sont de 896,62 ppm. Les teneurs en Zinc dans les sols proches de la cimenterie de Bouskoura sont prĂ©dominantes par rapport aux autres Ă©lĂ©ments et sont de 537,22 ppm. Dans les sols de MohammediaBenslimane, les teneurs de Cadmium sont de 2 ,36 ppm . Les teneurs en Plomb dĂ©passent rarement 100 ppm.L’étude statistique par le test d’Anova montre des diffĂ©rences significatives entre tous les sites pour tous les Ă©lĂ©ments traces mĂ©talliques sauf pour le Nickel. Chemical pollution in the peri-urban area of Casablanca impacts the quality of agricultural soils.Five sites from the region of Casablanca have been studied: Oued Hassar, Oued Merzeg, Bouskoura, Benslimane-Mohammedia, and Bouznika.The objective is the comparative analysis of five trace metal elements in soils in order to assess the environmental state and to preserve the potential and harmlessness of sites in the Casablanca region.The environmental state of these sites requires knowledge of the physico-chemical parameters of the soil (PH, Calcium carbonates, organic matter), following the degradation of irrigation water by the use of wastewater or the impact of chemical pollution.The environmental state studied through metallic trace elements shows that the soils of sites irrigated by Oued Hassar have cadmium and lead contents which exceed the standards recommended by the World health organisation (WHO), respectively 2 ppm and 100 ppm.The contents are respectively 2,91 ppm and 137,61ppm.The copper contents in the soils irrigated by the Merzeg wadi remain the highest.The contents are 896,62 ppm. The zinc contents in soils near the Bouskoura cement plant are predominant compared to the other elements.The contents are 537,22 ppm. In Mohammedia-Benslimane soils, the cadmium contents are very variable, moderate and can exceed 2 ppm. Lead levels rarely exceed 100 ppm.The statistical study by the Anova test shows significant differences in the contents of metallic trace elements except for nickel

    Neural Network in Fixed Time for Collision Detection between Two Convex Polyhedra

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    In this paper, a different architecture of a collision detection neural network (DCNN) is developed. This network, which has been particularly reviewed, has enabled us to solve with a new approach the problem of collision detection between two convex polyhedra in a fixed time (O (1) time). We used two types of neurons, linear and threshold logic, which simplified the actual implementation of all the networks proposed. The study of the collision detection is divided into two sections, the collision between a point and a polyhedron and then the collision between two convex polyhedra. The aim of this research is to determine through the AMAXNET network a mini maximum point in a fixed time, which allows us to detect the presence of a potential collision

    Similitude: Interfacing a Traffic Simulator and Network Simulator with Emulated Android Clients

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    Mobile phone apps are increasingly part and parcel of today's intelligent transportation systems (ITS). Evaluating these apps at scale requires modeling of phones and networks, along with vehicles, people and roads. In this paper, we present Similitude, a system comprising a traffic simulator, network simulator, and cluster of Android emulators that has applications in mobile app development as well as modern transport simulation. Apps with their wireless network stack are run on an Android emulator, with network packet delivery modeled in detail via a network simulator. Each phone's location and human interaction elements are obtained through interfacing with a microscopic traffic simulator running driver and pedestrian behavioral models. A prototype of the system is shown to scale well up to 300 simultaneous connected Android emulators, with individual system components scaling upwards of thousands of agents. An ITS app that does road space rationing is used as the case study demonstrating a potential use case of Similitude

    Caractérisation physico-chimique des argiles fibreuses de « Souk el Arbaa » du Gharb, Maroc

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    Le prĂ©sent travail s’intĂ©resse Ă  l’étude de la qualitĂ© industrielle des argiles fibreuses de ‘Souk El Arbaa’ du Gharb appartenant Ă  l’étage gĂ©ologique EocĂšne-MiocĂšne. Cette Ă©tude a rĂ©vĂ©lĂ© Ă  travers l’analyse d’une vingtaine d’échantillons, prĂ©levĂ©s sur des niveaux marneux variĂ©s, par spectromĂ©trie Ă  fluorescence X une carence en fer, une richesse en CaO, des taux plus ou moins Ă©levĂ©s en Al2O3. La diffractomĂ©trie aux rayons X a permis de mettre en Ă©vidence une composition minĂ©ralogique assez variĂ©e dans les diffĂ©rents Ă©chantillons analysĂ©es, dominĂ©e par la prĂ©sence de paragenĂšses minĂ©ralogiques composĂ©es de calcite, dolomite, quartz, sĂ©piolite et attapulgite (argiles fibreuses). Ainsi, le chimisme des Ă©chantillons analysĂ©s indique d’une façon inĂ©luctable que les argiles de ‘Souk El Arbaa’ du Gharb nĂ©cessitent un traitement afin de les rendre exploitables pour la production de cĂ©ramique d’excellente qualitĂ©.Mots-clĂ©s : qualitĂ© industrielle, argiles fibreuses, EocĂšne-MiocĂšne, cĂ©ramique, Maroc

    Cellular players that shape evolving pathology and neurodegeneration following traumatic brain injury

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    Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide, and has emerged as a critical risk factor for multiple neurodegenerative diseases, particularly Alzheimer’s disease (AD). How the inflammatory cascade resulting from mechanical stress, axonal shearing and the loss of neurons and glia following initial impact in TBI, contributes to the development of AD-like disease is unclear. Neuroinflammation, characterized by blood-brain barrier (BBB) dysfunction and activation of brain-resident microglia and astrocytes, resulting in secretion of inflammatory mediators and subsequent recruitment of peripheral immune cells has been the focus of extensive research in attempts to identify drug-targets towards improving functional outcomes post TBI. While knowledge of intricate cellular interactions that shape lesion pathophysiology is incomplete, a major limitation in the field is the lack of understanding of how distinct cell types differentially alter TBI pathology. The aim of this review is to highlight functional differences between populations of bone marrow derived, infiltrating monocytes/macrophages and brain-resident microglia based on differential expression of the chemokine receptors CCR2 and CX3CR1. This review will focus on how unique subsets of mononuclear phagocytes shape TBI pathophysiology, neurotoxicity and BBB function, in a disease-stage dependent manner. Additionally, this review summarizes the role of multiple microglia and macrophage receptors, namely CCR2, CX3CR1 and Triggering Receptor Expressed on Myeloid Cells-2 (TREM2) in pathological neuroinflammation and neurodegeneration vs. recovery following TBI. TREM2 has been implicated in mediating AD-related pathology, and variants in TREM2 are particularly important due to their correlation with exacerbated neurodegeneration. Finally, this review highlights behavioral outcomes associated with microglial vs. macrophage variances, the need for novel treatment strategies that target unique subpopulations of peripheral macrophages, and the importance of development of therapeutics to modulate inflammatory functions of brain-resident microglia at specific stages of TBI

    ENHANCING MOTIVATION TO WORK IN UNEMPLOYED PERSONS: LITHUANIA IN THE CONTEXT OF EU

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    This article provides an overview of the research in the area of motivation and activation of the unemployed and analyses work incentives for the unemployed applied in individual OECD and EU countries. In addition, the article provides the analysis of macro-level financial aspects of motivation to work in Lithuania and micro-level findings of a survey of persons registered with the Lithuanian Labour Exchange. It was found out that, in relative terms, employees should be interested in taking up low-paid jobs, but the low wage level does not ensure a decent living in reality. As a result, a relatively high portion of employees prefer undeclared work and social benefits to official employment. Findings of the survey of persons registered with the Lithuanian Labour Exchange have showed that satisfactory pay level is the strongest factor motivating persons to enter the labour market
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