31 research outputs found

    Optimal Scheduling of Multiproduct Pipeline System Using MILP Continuous Approach

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    Part 5: Planning and Scheduling; International audience; To date, the multiproduct pipeline transportation mode has nationally and internationally considerably evolved thanks to his efficiently and effectively of transporting several products. In this paper, we focus our study on the scheduling of a multiproduct pipeline system that receives a number of petroleum products (fuels) from a single refinery source in order to be distributed to several storage and distribution centers (depots). Mixed Integer Linear Programming (MILP) continuous mathematical approach is presented to solve this problem. The sequence of injected products in the same pipeline should be carefully studied, in order to meet market demands and ensure storage autonomy of the marketable pure products in the fuels depots on the one hand and to minimize the number of interfaces; Birth zone of mixture between two products in contact and in sequential flow, which may hinder the continuous operation of the pipeline system, by the necessity of additional storage capacity for this last mixture, that is in no way marketable and requires special processing operations. This work is applied on a real case of a multiproduct pipeline that feeds the western and southwestern region of Algeria with fuels. The obtained results based on the MILP continuous approach give an optimal scheduling of the multiproduct transport system with a minimized number of interfaces. Document type: Conference objec

    [does The Criterion For Prostate Biopsy Indication Impact Its Accuracy? A Prospective Population-based Outpatient Clinical Setting Study].

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    Prostate specific antigen (PSA) and digital rectal examination (DRE) are the main tests for initial prostate investigation; there is no consensus about the best criterion for prostate biopsies. We aim to check the accuracy of different criteria in this context including PSA derivatives to detect prostate cancer. Four different criteria for indication of prostate biopsy were compared: (A) PSA-density (>15 ng/ ml/ cc); (B) PSA > 2,5 ng/ml; (C) PSA-velocity (> 0.7 ng/ ml/ year); (D) free/total PSA ratio ( 0.05). Associating positive DRE with changed PSA, the PPV increased to 50%, 50%, 43.9% and 68.2% for criteria A, B, C and D, respectively (p>0.05). In univariate analysis, DRE (positive versus negative), PSA level (>10 ng/ ml versus 15%) and age were associated with PC. In multivariate analysis only positive DRE was associated with prostate cancer. All the criteria of PSA derivatives are complementary and useful predictors of cancer risk. However, a positive DRE increased the PPV of PSA derivatives. New tools are needed to improve the accuracy of prostate cancer detection.3510-
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