Arts et Métiers ParisTech

About: Arts et Métiers ParisTech is a education organization based out in Paris, France. It is known for research contribution in the topics: Finite element method & Machining. The organization has 3946 authors who have published 6693 publications receiving 142083 citations. The organization is also known as: École nationale supérieure d'arts et métiers & ENSAM.

Combining the logarithmic strain and the full-network model for a better understanding of the hyperelastic behavior of rubber-like materials

Abstract: Suitably defined invariants of the logarithmic strain are shown to be more adequate than the usual invariants of the left Cauchy–Green tensor to define the type and intensity of a strain applied to hyperelastic rubber-like materials. Coupling these invariants with the macromolecular full-network model clarifies some features of the state of strain dependence of these materials. Finally, comparisons of the model with experimental data illustrate the efficiency of the full-network model and the dependence of the material parameters on the applied loading history.

Rare sexual reproduction events in the clonal reproduction system of introduced populations of the little fire ant

Abstract: A unique reproductive system has previously been described in Wasmannia auropunctata, a widespread invasive ant species, where males are produced clonally, female queens are parthenogens, and female workers are produced sexually. However, these findings were mostly based on samples originating from only a limited part of the native range of the species in South America. We used microsatellite markers to uncover the reproductive modes displayed by a large number of nests collected in various invasive W. auropunctata populations introduced 40 years ago into New Caledonia, where the species now forms a single 450-km-long supercolony. Although the main reproduction system in New Caledonia remained clonality for both male and female reproductives, we found evidence of rare sexual reproduction events that led to the production of both new queen and male clonal lineages. All clonal lineages observed in New Caledonia potentially derived from sexual reproduction, recombination, and mutation events from a single female and a single male genotype. Hence, the male and female gene pools are not strictly separated in New Caledonia and the two sexes do not follow independent evolutionary trajectories. Our results also suggest genetic determination for both parthenogenesis and caste. We discuss the evolutionary implications of the emergence of sex in the clonal reproduction system of introduced populations of W. auropunctata.

Survey of methods for design of collaborative robotics applications- Why safety is a barrier to more widespread robotics uptake

Abstract: While collaborative robots have made headlines through recent industrial applications, they are not as widespread in industry as it may seem. The authors of this paper believe that one reason for this slow uptake is due to the high requirements on the safety and the lack of engineering tools for analyzing collaborative robotics applications. Systems engineering provides a good framework for creating the engineering tools needed for faster and more reliable deployment, but has only recently been applied to robotics challenges. In this paper, we discuss the state of the art for designing robotics applications featuring human-robot collaboration (HRC) and then review existing systems engineering approaches, which could offer support. Our review aims to support the robotics community in the future development of engineering tools to better understand, plan, and implement applications featuring collaborative robotics.

Network layer attacks and countermeasures in cognitive radio networks: A survey

Abstract: Spectrum scarcity is the principal motivation behind the development of cognitive radio. This technology introduces new functionalities at the physical, medium access control, and network layers of the TCP/IP protocol stack. These functionalities can be subject to new security threats. Most of the existing works in cognitive radio focused on the security issues in both the physical and medium access control layers. However, threats related to the network layer have not been studied despite its importance in establishing communication between different users in cognitive radio networks. In this paper, we classify and give an overview of attacks that target the network layer functionalities of cognitive radio networks. We discuss the existing detection techniques and countermeasures and highlight the main security challenges for such networks.