An allocation scheme for estimating the reliability of a parallel-series system

We give a hybrid two stage design which can be useful to estimate the reliability of a parallel-series and/or by duality a series-parallel system, when the component reliabilities are unknown as well as the total numbers of units allowed to be tested in each subsystem. When a total sample size is fixed large, asymptotic optimality is proved systematically and validated via Monte Carlo simulation.Comment: 16 pages, 4 figure

TUNWeeds: A Smart Identification Tool for Brassicaceae Weeds in Rapeseed (Brassica napus) Crop in Tunisia

Rapeseed is the second oilseed in the world. Its cultivation requires successful weed control. Weed identification is critical in weed management programs. Two surveys of common weeds in rapeseed fields allowed us to identify a wide specific diversity of weed flora and a great identification difficulty of certain specimens. To facilitate this task, we have developed a web application (TUNWeeds) for Tunisian farmers and students. At first, we limited our database to 44 Brassicaceae weeds. Subsequently, we plan to extend this application to other botanical families. TUNWeeds can help farmers in chemical weed control, manage herbicide resistance problems, and monitor weed flora

Impacts of bracteole removal and seeding rate on seedling emergence of halophyte shrubs: implications for rangeland rehabilitation in arid environments

Direct seeding techniques often result in unsatisfactory outcomes in rangeland rehabilitation, primarily because of low seedling emergence and poor establishment. Seed processing techniques aimed at improving seedling emergence have gained interest by pasture managers. The purpose of this study was to investigate the combined effects of bracteole removal and seeding rate on seedling emergence in seven halophytic species: Atriplex halimus, A. canescens, A. leucoclada, A. nummularia, A. lentiformis, Salsola vermiculata and Haloxylon aphyllum under semi-arid conditions in Tel Hadya (Syria). Each of these species was evaluated for seedling emergence under two seed treatments (bracteoles removed and non-removed bracteoles) with three seeding rates (10, 30 and 60 seeds per pot), in a completely randomised block design. The results showed a positive effect of seed treatment on seedling emergence for all studied species. The native A. halimus had the highest emergence percentages whereas the introduced A. mummularia, had the lowest. However, there were no significant effects of seeding rates on seedling emergence. These results showed that bracteole removal could improve germination and seedling emergence, and potentially increase the rate of establishment of the species studied. Therefore, when implementing rangeland rehabilitation projects, bracteole removal needs to be considered. The native S. vermiculata should be recommended for direct seeding in the West Asia and North Africa region given its high seedling emergence, known high palatability, nutritive value, and high auto-regeneration performance

Procédures d’échantillonnage efficaces : Estimation de la fiabilité des systèmes séries/parallèles

International audienceThis work consists to determine in a practical and straightforward manner some efficient sequential sampling schemes in order to estimate the product of Bernoulli parameters. The sampling schemes given by the literature are complex and costly. The results are useful for estimating the reliability of series/parallel systems where the allocation of the number of units to be tested from each component can be effective for minimizing the variance of the estimator.Ce travail consiste à déterminer, de façon pratique et facile à utiliser, des plans séquentiels d’échantillonnage efficaces pour estimer le produit de paramètres de Bernoulli. Les procédures d’échantillonnage fournies par la littérature sont complexes et coûteuses. Les résultats sont utiles pour estimer la fiabilité des systèmes en série/parallèle où le choix du nombre des unités à tester dans chaque composant peut être effectif pour minimiser la variance de l’estimateur

4th International Symposium on Environmental Weeds and Invasive Plants. Abstracts

absen