77 research outputs found

    Integration of a Flat Holonic Form in an HLA Environment

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    International audienceManagers need to create and sustain internal systems and controls to ensure that their customer focused strategies are being implemented. Companies are currently in a spiral of permanent optimization. Accordingly, many companies turn to their core activity. In this framework, one notices the development of the concept of “industrial partnership”. In this context and to control the customer–supplier relationships (CSR), we proposed a self-organized control model in which all partner entities (customers/suppliers) negotiate to guarantee good quality connections between customers and suppliers. This means meeting customer expectations as closely as possible and respecting supplier capacities. In this proposal, self-organized control is characterized more precisely by an organizational architecture of the flat holonic form type. This flat holonic form is based on the concept of autonomous control entity (ACE). The holonic architecture, the behaviour of an ACE, the interaction mechanisms between ACEs and the self-evaluation supplier process are presented, and then the modelling of ACEs using discrete event system specification (DEVS) is described. An implementation of the simulation of such a system was done via a distributed simulation environment high level architecture (HLA). A case study illustrating the proposed approach is presented

    Customers-Suppliers Relationship Management in an Intelligent Supply Chain

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    International audienceOutsourcing is leading to more and more complex industrial organizations. This can be attributed to the fact that several decisions centres interact. As a consequence, changes in customers-suppliers relationships can be noticed. In recent years, these relations have strongly evolved to lead to better internal management of each partner and a better general performance to satisfy customers. These evolutions created a new approach of the relations between companies, called ‘industrial partnership’, in the form of a network. Networks induce a need at customers-suppliers relation control level. The contribution and participation of each of the partners are thus fundamental to make Supply Chain Management (SCM) a successful project. The control system of each actor partner must thus be adaptable enough to satisfy the production requirements. Our contribution to the improvement of customers-suppliers relationship is a decentralized self-organized control model. In this model, the decision system manages a group of actors’ operations who are in a partnership (part of companies network). In this paper, we, particularly discuss a process for the evaluation of the suppliers network

    Another way to manage supply chains: holonic and multicriteria approach

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    International audienceToday’s suppliers are challenged to deliver quality to their customers. Managers need to create and sustain internal systems and controls to ensure that their customers-focused strategies are being implemented. Many companies increasingly turn to their core activities to improve their reactivity and to manage their costs. This paper proposes an approach for self-organized control of relations between companies in which all the members of a partnership negotiate to guarantee good quality connections between customers and suppliers. Each partner is associated with a decision- making entity named “Autonomous Control Entity” (ACE) through which he can evaluate his performance. The integration of these ACEs into a holonic control system is presented. Operations of an ACE have been modelled through the Discrete EVent system Specification (DEVS) formalism. Then, the validation of such a control system for a self-organized logistic partnership network was done through a distributed High Level Architecture (HLA) simulation environmen

    Obtention de rigidité variable d'une structure robotique par l'utilisation d'un alliage à mémoire de forme

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    Dans ce papier sont présentées les cartes de rigidité d'une structure robotique à grande déflection sous différents modes d'actionnement. Dans l'application présentée, l'intégration redondante d'un élément actif en alliage à mémoire de forme (AMF) en plus de deux moteurs rotatifs permet d'obtenir une variation de la rigidité globale de la structure, par exploitation de l'effet mémoire de forme. La modélisation numérique par éléments finis du système mécanique est tout d'abord présentée. Le démonstrateur physique fabriqué pour la validation expérimentale est ensuite introduit avec ses caractéristiques, notamment celles du ressort AMF utilisé. Les résultats numériques et expérimentaux sont enfin exposés sous forme de cartes de rigidité numériques et expérimentales

    Antidiabetic, antioxidant and anti inflammatory properties of water and n-butanol soluble extracts from Saharian Anvillea radiata in high-fat-diet fed mice

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    International audienceEthnopharmacological relevance: According to Saharian traditional medicine, Anvillea radiata Coss. & Dur. (Asteraceae) has been valued for treating a variety of ailments such as gastro-intestinal, liver and pulmonary diseases, and has gained awareness for its beneficial effect on postprandial hyperglycemia. However, to best of our knowledge, no detailed study of the antidiabetic curative effects of this plant has been conducted yet.Aim of the study: To determine the hypoglycemic and antidiabetic effect of dietary supplementation with Anvillea radiata extracts on high-fat-diet (HFD)-induced obesity and insulin resistance in C57BL/6J mice in relation with antioxidant, anti-inflammatory, pancreatic beta-cells and skeletal muscle protection, and digestive enzyme inhibiting properties.Materials and methods: Six extracts (water soluble and organic) from aerial parts of the plant were analyzed phytochemically (total phenolic and flavonoid content) and screened for in vitro superoxide (by chemiluminescence) and hydroxyl radical (by electron paramagnetic resonance spin-trapping) scavenging, antioxidant (DPPH, TRAP and ORAC assays), xanthine oxidase, metal chelating, α-amylase and α-glucosidase inhibitory property, and protective effects on copper-induced lipoprotein oxidation. Then selected hydroalcoholic and aqueous extracts were assessed for toxicity in normal human lung fibroblasts and A549 cancer cells using FMCA and MTT assays. Two water-soluble extracts having the best overall properties were assessed for their (i) protective effect at 115 µg/mL on metabolic activity of rat insulinoma-derived INS-1 cells exposed to hyperglycemic medium, and (ii) acute hypoglycemic effect on 16-weeks HFD-induced diabetic mice. Then diabetic mice were administered HFD supplemented by extracts (up to 150 mg/kg/day) for 12 additional weeks using standard diet as control and the antidiabetic drug, metformin (150 mg/kg), as positive control. Then the antidiabetic, anti-inflammatory and antioxidant activity of extracts were determined.Results: Of the highly efficient polyphenolics-enriched hydroalcoholic and ethyl acetate extracts, the lyophilized aqueous (AQL) and butanol extracts were not toxic in cells (≤ 400 µg/mL) or when given orally in normal mice (≤ 2000 mg/kg), exerted a dose-dependent hypoglycemic action in diabetic mice, which was maximal at the dose of 150 mg/kg. Upon administering this dose for 12 weeks, both extracts significantly ameliorated body weight control capacity, recovery of plasma glucose and insulin level, reduced oxidative stress in blood, myocardial and skeletal muscles, and improved hyperlipidemic and inflammatory status. Moreover, diabetes-related complications were optimally ameliorated by oral therapy based on halved doses (75 mg/kg) of a mixture of AQL and metformin.Conclusions: Current investigation supports the traditional medicinal usage of Anvillea radiata and suggests that both readily accessible and low-cost bio-extracts have the potency to develop an antihyperglycemic, antihyperlipidemic and protective agent against beta-cells and muscle dysfunction at doses compatible with the common practices of indigenous people for the management of metabolic disorders

    Robots in machining

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    Robotic machining centers offer diverse advantages: large operation reach with large reorientation capability, and a low cost, to name a few. Many challenges have slowed down the adoption or sometimes inhibited the use of robots for machining tasks. This paper deals with the current usage and status of robots in machining, as well as the necessary modelling and identification for enabling optimization, process planning and process control. Recent research addressing deburring, milling, incremental forming, polishing or thin wall machining is presented. We discuss various processes in which robots need to deal with significant process forces while fulfilling their machining task

    Un systeme multi-experts pour la recherche documentaire

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    SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 82751 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

    Design and analysis of a compliant robot with active stiffness by means of shape memory alloy

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    La rigidité est un des objectifs de performance les plus importants pris en compte lors de la conception de systèmes robotiques. Le contrôle de la raideur physique en cours de tâche est une problématique scientifique en plein essor dans le cadre de la conception innovante de robots à forte polyvalence. L’association d’une structure robotique compliante et d’un composant en alliage à mémoire de forme (AMF) est réalisée dans le but d’obtenir des cartes de compliance variables dans le temps sur un même espace de travail. Les AMF sont en effet des matériaux actifs qui possèdent des caractéristiques comportementales pouvant être exploitées dans cette application. La structure considérée pour l’étude n’a pas de degré de liberté interne mais sa déformation permet de créer un pseudo-espace de travail. Celui-ci diffère selon l’état activé/non-activé de l’AMF. L’intersection des deux espaces obtenus représente alors les positions de l’effecteur où il est possible d’avoir des valeurs de compliance différentes. Les cartes obtenues montrent des caractéristiques intéressantes pour la perspective de la conception de robots polyvalents ayant une nouvelle forme de reconfigurabilité basée sur le changement de propriétés matérielles.The rigidity is one of the most important performance targets which is taken into account for the design of robotic systems. The control of the physical stiffness during industrial tasks is a scientific issue which is rapidly expanding in the context of the innovative design of highly polyvalent robots. The combination of a compliant robotic structure and a shape memory alloy (SMA) component is carried out in the aim of obtaining variable compliance maps over time and in the same workspace. SMAs are actually active materials with specific thermomechanical properties which can be used in this application. The considered structure has no internal degree of freedom, but the deformation of the arms allows the creation of a “Pseudo-Workspace” (PWS). This PWS varies as a function of the activated/non-activated state of the SMA component. The intersection of the two obtained PWSs represents the effector’s positions where it is possible to have different compliance values. Generated maps show interesting characteristics in the perspective of the design of polyvalent robots based on a new type of reconfigurability (change of material properties)

    Conception et analyse d'un robot flexible à rigidité active au moyen d'un alliage à mémoire de forme

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    The rigidity is one of the most important performance targets which is taken into account for the design of robotic systems. The control of the physical stiffness during industrial tasks is a scientific issue which is rapidly expanding in the context of the innovative design of highly polyvalent robots. The combination of a compliant robotic structure and a shape memory alloy (SMA) component is carried out in the aim of obtaining variable compliance maps over time and in the same workspace. SMAs are actually active materials with specific thermomechanical properties which can be used in this application. The considered structure has no internal degree of freedom, but the deformation of the arms allows the creation of a “Pseudo-Workspace” (PWS). This PWS varies as a function of the activated/non-activated state of the SMA component. The intersection of the two obtained PWSs represents the effector’s positions where it is possible to have different compliance values. Generated maps show interesting characteristics in the perspective of the design of polyvalent robots based on a new type of reconfigurability (change of material properties).La rigidité est un des objectifs de performance les plus importants pris en compte lors de la conception de systèmes robotiques. Le contrôle de la raideur physique en cours de tâche est une problématique scientifique en plein essor dans le cadre de la conception innovante de robots à forte polyvalence. L’association d’une structure robotique compliante et d’un composant en alliage à mémoire de forme (AMF) est réalisée dans le but d’obtenir des cartes de compliance variables dans le temps sur un même espace de travail. Les AMF sont en effet des matériaux actifs qui possèdent des caractéristiques comportementales pouvant être exploitées dans cette application. La structure considérée pour l’étude n’a pas de degré de liberté interne mais sa déformation permet de créer un pseudo-espace de travail. Celui-ci diffère selon l’état activé/non-activé de l’AMF. L’intersection des deux espaces obtenus représente alors les positions de l’effecteur où il est possible d’avoir des valeurs de compliance différentes. Les cartes obtenues montrent des caractéristiques intéressantes pour la perspective de la conception de robots polyvalents ayant une nouvelle forme de reconfigurabilité basée sur le changement de propriétés matérielles
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