29 research outputs found

    Decision support framework for supply chain planning with flexible demand

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    The most challenging issue of today’s production management is certainly to manage networked organisations under an uncertain demand so that to provide a good service to the customer at low cost. In this article, a model of the decision making parameters involved in this management process is suggested, on the base of case studies. A mixed integer linear planning model embedded in a framework simulating a rolling horizon planning process is described on the base of this analysis. The model takes into account the capabilities of reaction of the planned system and of its environment (suppliers, subcontractors and customers), as well as the corresponding costs. The suggested simulation framework may assist the decision maker for coping with an uncertain or flexible demand, using various planning strategies. Some possible applications of this simulation framework are given in order to illustrate how it can help to solve various types of practical planning problems

    European pollen-based REVEALS land-cover reconstructions for the Holocene: methodology, mapping and potentials

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    Quantitative reconstructions of past land cover are necessary to determine the processes involved in climate–human–land-cover interactions. We present the first temporally continuous and most spatially extensive pollen-based land-cover reconstruction for Europe over the Holocene (last 11 700 cal yr BP). We describe how vegetation cover has been quantified from pollen records at a 1∘ × 1∘ spatial scale using the “Regional Estimates of VEgetation Abundance from Large Sites” (REVEALS) model. REVEALS calculates estimates of past regional vegetation cover in proportions or percentages. REVEALS has been applied to 1128 pollen records across Europe and part of the eastern Mediterranean–Black Sea–Caspian corridor (30–75∘ N, 25∘ W–50∘ E) to reconstruct the percentage cover of 31 plant taxa assigned to 12 plant functional types (PFTs) and 3 land-cover types (LCTs). A new synthesis of relative pollen productivities (RPPs) for European plant taxa was performed for this reconstruction. It includes multiple RPP values (≥2 values) for 39 taxa and single values for 15 taxa (total of 54 taxa). To illustrate this, we present distribution maps for five taxa (Calluna vulgaris, Cerealia type (t)., Picea abies, deciduous Quercus t. and evergreen Quercus t.) and three land-cover types (open land, OL; evergreen trees, ETs; and summer-green trees, STs) for eight selected time windows. The reliability of the REVEALS reconstructions and issues related to the interpretation of the results in terms of landscape openness and human-induced vegetation change are discussed. This is followed by a review of the current use of this reconstruction and its future potential utility and development. REVEALS data quality are primarily determined by pollen count data (pollen count and sample, pollen identification, and chronology) and site type and number (lake or bog, large or small, one site vs. multiple sites) used for REVEALS analysis (for each grid cell). A large number of sites with high-quality pollen count data will produce more reliable land-cover estimates with lower standard errors compared to a low number of sites with lower-quality pollen count data. The REVEALS data presented here can be downloaded from https://doi.org/10.1594/PANGAEA.937075 (Fyfe et al., 2022)

    Testing the Effect of Relative Pollen Productivity on the REVEALS Model : A Validated Reconstruction of Europe-Wide Holocene Vegetation

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    Reliable quantitative vegetation reconstructions for Europe during the Holocene are crucial to improving our understanding of landscape dynamics, making it possible to assess the past effects of environmental variables and land-use change on ecosystems and biodiversity, and mitigating their effects in the future. We present here the most spatially extensive and temporally continuous pollen-based reconstructions of plant cover in Europe (at a spatial resolution of 1° × 1°) over the Holocene (last 11.7 ka BP) using the 'Regional Estimates of VEgetation Abundance from Large Sites' (REVEALS) model. This study has three main aims. First, to present the most accurate and reliable generation of REVEALS reconstructions across Europe so far. This has been achieved by including a larger number of pollen records compared to former analyses, in particular from the Mediterranean area. Second, to discuss methodological issues in the quantification of past land cover by using alternative datasets of relative pollen productivities (RPPs), one of the key input parameters of REVEALS, to test model sensitivity. Finally, to validate our reconstructions with the global forest change dataset. The results suggest that the RPPs.st1 (31 taxa) dataset is best suited to producing regional vegetation cover estimates for Europe. These reconstructions offer a long-term perspective providing unique possibilities to explore spatial-temporal changes in past land cover and biodiversity

    Isoarchic and Multi-criteria Control of Supply Chain Network

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    International audienceSupply chains and more particularly supply chains networks are more and more subjected to extreme dynamic operations, where it is asked to each actor more flexibility and reactivity on the one hand and a specialization bringing more productivity on the other hand. Companies try to achieve the common goal of satisfying customers’ needs through partnership. Negotiation between partners is thus required involving each partner management and production organization. This situation makes difficult to obtain the best response with respect to the need of each customer. For that, a new approach is proposed for customer-supplier relationship control, in which the partnership is considered in the context of an association of potential suppliers within a network: an isoarchic control model for supply chains network based on a holonic architecture. The decision-making mechanism is produced thanks to the properties of a decision-making centre, called Autonomous Control Entity (ACE), associated to each actor of the logistic network, which makes it possible to quantify a multi-criteria evaluation. An implementation of the simulation of such a system is done via a distributed simulation environment HLA (High Level Architecture). A case study is presented

    A method to select a successful interoperability solution through a simulation approach

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    (2) Evaluating the accessibility of each project regarding the current state of the organizationEnterprise applications and software systems need to be interoperable in order to achieve seamless business across organizational boundaries and thus realize virtual networked organizations. Our proposition can be considered as an interoperability project selection approach and is based on three steps: (1) Modelling both collaborative business processes and potential related interoperability project

    Crisis management and human resource development: towards research agenda

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    Crisis management has widened as a concept and as a set of practices and in the form of human resource development has become part of a more strategic approach to integrate HR activities and business policies. A strategic approach to HRD is imperative as it involves designing and implementing HRD policies and practices to ensure that a firm’s human capital contributes to the achievement of business objectives specified in this globalization era. To ensure the crisis management requires the firm-specific capabilities it must integrate with the high-level strategic integration between HRD, organizational structure, culture, and strategy. This article identifies and discusses a number of themes and trends that together make up the developing research agenda for this field. In reviewing these emerging areas of research, the articles seek to explore some of the implications for HRD practices at both organizational and individual levels
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