178 research outputs found
A new process quality-based multi-objective multi-part approach for the integrated process planning and scheduling (IPPS) problem in reconfigurable manufacturing environment
Get PDFThis paper addresses the so-called integrated process planning and scheduling (IPPS) problem in a reconfigurable manufacturing environment. Process planning and scheduling are two important and complex functions in manufacturing. To reduce the problem complexity, they are considered sequentially by traditional approaches. In this paper, we consider the simultaneous integration of both functions by developing a heuristic approach to solve the IPPS problem in a reconfigurable environment. Reconfigurable manufacturing systems (RMSs) comprise of a set of machines distinguished by multiple working configurations and tools. Each machine can perform a certain number of operations based on its configurations and their availability. The purpose of the proposed heuristic approach is to find the best assignment of operations to machines while considering process-quality. Finally, to demonstrate the approach applicability, an illustrative numerical example is presented and the results discussed
Modularity and integrability-based energy minimization in a reconfigurable manufacturing environment: A non-linear mixed integer formulation
Get PDFNowadays, manufacturing environment is characterized by the necessity of customized flexibility as well as responding rapidly and cost-effectively to changing market demands while minimizing impacts on environment and society. To reach these goals, a key paradigm called sustainable manufacturing can be coupled with reconfigurable manufacturing systems (RMSs). The coupling of RMS characteristics and sustainability concerns is a basis to develop a new generation of sustainable production systems. This paper outlines sustainability in a reconfigurable environment from an energy consumption point of view. A nonlinear mathematical model is developed to optimize the energy consumption of a RMS through a redefinition of its core characteristics-modularity and integrability. The objective is to minimize the energy consumption of the system by selecting the most suitable modular machines from a set of candidate machines. The optimization problem is addressed using an exhaustive search heuristic. Finally, the applicability of the proposed approach is illustrated through a simple numerical example and the discussion of the obtained results
Safety, Ergonomics and Human Factors in Reconfigurable Manufacturing Systems
No full textIn the recent years, the adoption of reconfigurable systems represents a primary strategy to improving flexibility, elasticity and efficiency in both manufacturing and assembly. Global markets, the increasing need for customization, high quality standards, dynamic batches and short life cycles are the key factors driving the transition from traditional to reconfigurable manufacturing systems (RMSs). Despite their automation level, such systems still require actions by human operators, e.g. material handling, WIP load/unload, tool setup, etc. These operations rise safety issues because of the human–machine interaction and cooperation. Particularly, RMSs require changes of auxiliary modules and tools, based on the manual intervention, to achieve effective system configurations enlarging the produced mix. In this field, embracing the emerging Industry 4.0 technology, a lack of procedures and reference approaches exists to supporting companies and practitioners in analysing the impact on safety and ergonomics coming from the switch from
standard to RMSs. This chapter, after revising the literature, standards and reference guidelines, converges to an innovative methodological and operative framework supporting and spreading the integration of safety, ergonomics and human factors in the emerging reconfigurable systems. Deep attention is paid to best-in-class examples, from industry, to strengthen the industrial perspective and applicability
Investigation of Hybrid Electrodes of Polyaniline and Reduced Graphene Oxide with Bio-Waste-Derived Activated Carbon for Supercapacitor Applications
Get PDF[EN] Graphene-based materials have been widely studied in the field of supercapacitors. However, their electrochemical properties and applications are still restricted by the susceptibility of graphene-based materials to curling and agglomeration during production. This study introduces a facile method for synthesizing reduced graphene oxide (rGO) nanosheets and activated carbon based on olive stones (OS) with polyaniline (PAni) surface decoration for the development of supercapacitors. Several advanced techniques were used to examine the structural properties of the samples. The obtained PAni@OS-rGO (1:1) electrode exhibits a high electrochemical capacity of 582.6 F center dot g-1 at a current density of 0.1 A center dot g-1, and an energy density of 26.82 Wh center dot kg-1; thus, it demonstrates potential for efficacious energy storage. In addition, this electrode material exhibits remarkable cycling stability, retaining over 90.07% capacitance loss after 3000 cycles, indicating a promising long cycle life. Overall, this research highlights the potential of biomass-derived OS in the presence of PAni and rGO to advance the development of high-performance supercapacitors.The authors would like to thank their parent universities for providing the necessary facilities to accomplish the present study. Moreover, the authors also acknowledge the financial support through Researchers Supporting Project number (RSPD2024R768), King Saud University, Riyadh, Saudi Arabia.Benchikh, I.; Ezzat, AO.; Sabantina, L.; Benmimoun, Y.; Benyoucef, A. (2024). Investigation of Hybrid Electrodes of Polyaniline and Reduced Graphene Oxide with Bio-Waste-Derived Activated Carbon for Supercapacitor Applications. Polymers. 16(3). https://doi.org/10.3390/polym16030421S16
Amélioration de la prévision des écoulements turbulents par une approche URANS avancée
Get PDFCes travaux de recherche ont pour but d évaluer la méthode dite de la "Simulation auxEchelles Adaptées" (SAS pour Scale-Adaptive Simulation). Cette approche coïncide avec uneapproche RANS classique dans les zones pariétales attachées et adapte le niveau de viscositéturbulente dans les zones décollées pour y permettre une résolution partielle des structures turbulentes.Dans une première partie, une analyse théorique du modèle SAS original a été menéeet a permis de développer une correction visant à favoriser l adaptation du niveau de viscositéturbulente dans les zones sièges d instabilités de type Kelvin-Helmholtz. Le modèle ainsi corrigéest nommé SAS-aL. Les modèles SAS et SAS-aL ont été implantés dans le code de calculNavier-Stokes elsA de l ONERA. À l issue de cette étape, trois cas académiques d écoulementsturbulents instationnaires, cylindre à grand nombre de Reynolds, marche descendante et cavitétranssonique, ont été simulés grâce aux trois modèles de turbulence SST, SAS et SAS-aL. Outreune comparaison aux bases de données expérimentales disponibles, une attention particulièrea été portée à l influence de paramètres numériques tels que des schémas numériques d ordreélevé. Enfin, afin d étudier la viabilité de l approche SAS dans un contexte industriel, les troismodèles de turbulence ont été testés sur une configuration issue de l industrie aéronautique etcorrespondant à la sortie d air chaud d un système de dégivrage des nacelles d avion. La comparaisondes prévisions obtenues avec les modèles SST, SAS et SAS-aL aux données expérimentalesobtenues à l ONERA a permis de montrer un gain de précision grâce à l emploi de l approcheSAS et ce pour un coût de calcul compatible avec un cycle de conception industrielle.This research work is meant to assess an upgraded URANS approach, namely the Scale-Adaptive Simulation (SAS). This method is similar to a conventional RANS approach (namelythe SSTmodel) in attached areas and is able to adapt the eddy-viscosity level in detached areas toensure the resolution, at least partially, of the turbulent structures. In a first part of this researchwork, an improvement of the SAS approach is suggestedto allowa better sensitivity of themodelto instabilities such as Kelvin-Helmholtz ones. This "improved" model is referred to as SAS-aLmodel. Both SAS and SAS-aL models were implemented in the ONERA Navier-Stokes solverelsA and both of themaswell as the SSTmodelwere tested on academic test cases : a cylinder in acrossflowat a high Reynolds number, a backward-facing step flowcorresponding to theDriver&Seegmiller experiment and the transonic flow over the M219 cavity experimentally investigatedby de Henshaw. The influence of the numerical parameters was deeply investigated and particularattention was paid to the high-order space-discretization schemes effects. The reliabilityof the SAS approach in an industrial framework was assessed on an aeronautic configurationnamely a nacelle de-icing device. Comparisons between the threemodels (SST, SAS and SAS-aL)and an experimental database available at ONERA - The French Aerospace Lab have shown thebetter accuracy of the SAS approach as well as the high potential of the SAS-aL model.TOULOUSE-ISAE (315552318) / SudocSudocFranceF
A Rule-driven Approach for Defining the Behavior of Negotiating Software Agents
Get PDFOne problem with existing agent-mediated negotiation systems is that they rely on ad hoc, static, non-adaptive, and hardcoded schemes to represent the behaviour of agents. This limitation is probably due to the complexity of the negotiation task itself. Indeed, while negotiating, software (human) agents face tough decisions. These decisions are based not only on the information made available by the negotiation server, but on the behaviour of the other participants in the negotiation process as well. The information and the behaviour in question are constantly changing and highly uncertain. In the first part of the paper, we propose a rule-driven approach to represent, manage and explore negotiation strategies and coordination information. For that, we divide the behaviour of negotiating agents into protocols, strategies and coordination. Among the many advantages of the proposed solution, we can cite the high level of abstraction, the closeness to human understanding, the versatility, and the possibility to modify the agents' behaviour during the negotiation process. To validate our solution, we ran many agent tournaments, and used the rule-driven approach to implement bidding strategies that are common in the English and Dutch auctions. We also implemented simple coordination schemes across several auctions. The ongoing validation work is detailed and discussed in the second part of the paper. Un des inconvénients qu'on retrouve fréquemment dans les systèmes de négociation par agents est qu'ils reposent sur des schémas ad-hoc, non adaptatifs et figés dans le code pour représenter le comportement des agents. Cette limitation est probablement due à la complexité de l'activité de négociation elle-même. En effet, au cours de la négociation, les agents logiciels (humains) ont des décisions difficiles à prendre. Ces décisions ne sont pas seulement basées sur l'information disponible sur le serveur de négociation, mais aussi sur le comportement des autres participants durant le processus de négociation. L'information et le comportement en question changent constamment et sont très incertains. Dans la première partie de l'article, nous proposons une approche à base de règles pour représenter, gérer et explorer les stratégies de négociation ainsi que l'information de coordination. Parmi les nombreux avantages de la solution proposée, on peut citer le haut niveau d'abstraction, la proximité avec la compréhension humaine, la souplesse d'utilisation et la possibilité de modifier le comportement des agents durant le processus de négociation. Pour valider notre solution, nous avons effectué plusieurs tournois entre agents et utilisé l'approche à base de règles pour implémenter des stratégies simples applicables à l'enchère anglaise et à l'enchère hollandaise. Nous avons aussi implémenté des schémas simples de coordination impliquant plusieurs enchères. Le travail de validation, en cours, est détaillé et discuté dans la seconde partie de l'article.e-negotiation, online auction, software agent, negotiation strategy, coordination, rule-based system, rule engine, Négociation électronique, enchères en ligne, agents logiciels, stratégie de négociation, coordination, système à base de règles, moteur de règles
Bibliographie
No full textAbdallah-Pretceille, M. (2006). La communication interculturelle : des signes d’appartenance aux symptômes d’une relation. Dans F. Dervin & E. Suomela-Salmi (Eds), Intercultural communication and Education (pp. 19-31). Zurich : P. Lang. Acherar, L., Benyoucef, B., & Philip, C. (2005). Vivre avec un handicap mental en situation d’immigration. Suresnes : CNEFEI. Akif, Z. (2003). Evaluation des compétences langagières en français et en arabe marocain d’enfants issus de l’immigration : une synthè..
Intelligent Manufacturing Systems
No full textThis chapter provides information on intelligent manufacturing systems including an analysis on change and historical progress of manufacturing systems as well as a brief review of traditional manufacturing systems. Fundamental technologies of artificial intelligence are also reviewed in order to establish the baseline for intelligent manufacturing systems. Following that, basic characteristics of intelligent manufacturing and respective architectures are provided. Some examples of the applications of intelligent manufacturing systems are highlighted
Bibliographie
No full textAbdallah-Pretceille, M. (2006). La communication interculturelle : des signes d’appartenance aux symptômes d’une relation. Dans F. Dervin & E. Suomela-Salmi (Eds), Intercultural communication and Education (pp. 19-31). Zurich : P. Lang. Acherar, L., Benyoucef, B., & Philip, C. (2005). Vivre avec un handicap mental en situation d’immigration. Suresnes : CNEFEI. Akif, Z. (2003). Evaluation des compétences langagières en français et en arabe marocain d’enfants issus de l’immigration : une synthè..
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