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International audience; The present study aimed at investigating the role of emotions on arithmetic performance. Previous findings showed that emotions can have both beneficial or detrimental effects on participants’ performance while they solve arithmetic problems (e.g., Fabre et al., 2022; Fabre & Lemaire, 2019; Kleinsorge, 2009; Lallement & Lemaire, 2021; Liu et al., 2021; Melani et al., 2023; Schimmack, 2005). For example, Melani et al. (2023) asked participants to verify arithmetic problems (e.g., 13x5=65. True? False). False problems respected or violated either the parity rule (i.e., a product must be even if either or both of its multipliers is even) or the five rule (i.e., N × 5 product that ends in 0 or 5). Each problem was preceded by an emotionally neutral or negative image. Melani et al. found that participants slowed down while verifying false five problems that violated both the five and parity rules or no rule, but that emotions had no influence while participants verified problems that violated only one (parity or five) rule. To further understand the underlying mechanisms for this role of emotions, the present study collected EEG in the same experiment carried out by Melani et al. (2023). Twenty-four participants were asked to verify complex multiplication problems (Figure 1) that were either true (e.g., 4 × 26 = 104) or false (e.g., 5 × 41 = 201). Half the problems were five problems (e.g., 5 × 28 = 140) and half were non-five problems (e.g., 6 × 36 = 216). False five problems violated the five-rule, the parity-rule, both rules, or no rule. Problems were preceded by emotionally neutral or negative pictures. Above and beyond replicating previous behavioural results, event-related potential (ERPs) documented the specific problem-verifcation processes on which emotions had an influence. For example, results showed important ERPs differences between negative and neutral emotion conditions during 550—850 ms post-stimulus presentation for both-rule violation problems. The data showed additional differences in ERPs for negative and neutral condition that also interacted with problem types both during the first 200-ms post-stimulus presentation, and after 1400 ms. These findings have important implications for furthering our understanding of the role of negative emotions on mechanisms that participants use to solve arithmetic problems.

International audience; Deciding, as early as the software architecture is designed, whether the resulting system will be secure is challenging. We propose three metrics inspired by a security-related design pattern in the structural architecture model, the "protected entry points" pattern. We evaluate these metrics on the real-life Bitwarden web client and server, as well as a synthetic system.

International audience; emotions on performance for different types of arithmetic problems and whether this influence changes with aging during adulthood. Based on previous research suggesting that participants use different strategies to solve different types of problems, finding age-related differences in how emotions influence participants' performance on different types of problems would suggest that the effects of emotions on arithmetic performance occur via different mechanisms in young and older adults. Before outlining the logic of the present work, we briefly review previous findings on arithmetic and on effects of negative emotions on arithmetic performance in young and older adults. Previous findings on arithmetic Research in arithmetic aims at determining the crucial factors that influence arithmetic performance and at deciphering mechanisms responsible for how these factors exert their influence. Previous research found that characteristics of tasks, participants, stimuli, and situations influence arithmetic performance. For example, participants are faster when they are asked to accomplish verification tasks (e.g., 4 + 8 = 12. True? False) than when they are asked to accomplish production tasks (e.g., 4 + 8 =?), when they solve tie Ludovic Fabre

Studied for more than a century, first in the field of geophysics, flows over rotating discs present a great diversity of complex instability behaviours that are not yet fully understood. While the primary instabilities are now well characterized experimentally, theoretically and numerically, their role in the transition mechanisms to turbulence remains an open question that still challenges the scientific community. This article brings together the main results of the literature related to the instabilities over rotating discs, but also in the connected problem of rotating cavities, and reviews the main scenarios currently assumed to describe the flow breakdown to turbulence. A particular focus is on more recent studies of generic flows in rotating cavities bounded by two coaxial rotating discs, that occur in many industrial systems, the performances of which and their improvement are linked to a better understanding of these mechanisms. This article is part of the theme issue ‘Taylor–Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper (part 1)’.

International audience; Stakeholders are key elements of complex technical projects. They can determine orientation, evolution and success of the project. They can cause uncertainties, changes in objectives and lead the project to failure. In this context, it is always more important to involve them in project decisions. Value Analysis (VA) is a means to introduce management and decision-making in design of complex projects, based on stakeholder needs. A method named Function Analysis aims at identifying and treating functions that the system has to complete. However, this functional approach does not allow some non-functional attributes to be included in the design phases. This is a lack identified by some engineering companies. The proposed paper aims at identifying the challenges encountered by the Stakeholder approaches to translate their needs into nonfunctional dimensions to deal with VA practices to design technical solutions. The research methodology combines a classical bibliographical analysis on VA that led us to show FA limits. Thus, we propose a Stakeholder-based “Non-Functional Analysis” to determine the non-functional attributes to characterize for the design of complex projects, and an industrial company’s feedback practices on a case study. This will allow practitioners to have a systems approach to Value in the context of a VA but it will also allow scientists to compare theory and lack of practice around the identification and characterization of the needs of a set of stakeholders.

International audience; In this study, we investigated the influence of negative emotions on numerosity estimation and whether this influence changes with aging during adulthood. Young and older adults were asked to estimate and compare the numerosity of collections of elements (cars or dots) with a two-digit number. Collections of elements were preceded by emotionally neutral (e.g., mushrooms) or emotionally negative (e.g., a corpse) pictures. Stimuli were easier (i.e., small-ratio) or harder (i.e., large-ratio) items. Young and older participants obtained similar numerosity estimation performance. Interestingly, participants were less accurate under negative emotions than under neutral emotions when they estimated numerosity of collections of abstract elements (i.e., dots). In contrast, participants improved their performance under negative emotions while estimating collections of non-abstract, daily-life elements (i.e., cars). These findings have important implications for furthering our understanding of the role of negative emotions in numerosity estimation and age-related differences therein.

The aerodynamic characteristics of two neighboring airfoils are greatly different from those of a single airfoil, for both attached and detached flow conditions. In order to study the features of a two-airfoil arrangement with variations in the angle of attack and distances between the airfoils, and considering possible flow detachments, an adaptation of a discrete-time vortex numerical method is conducted. It is based on the fact that for a given airfoil and Reynolds number, there is a critical value of the leading-edge suction parameter. If its instantaneous value exceeds the critical value, vortex shedding occurs at the leading edge, representing the shear layer associated with flow detachment. In addition, Kelvin’s theorem imposes for each time step that the total circulation equals zero. In the present paper, Kelvin’s theorem is extended for a two-airfoil arrangement with the initial starting flow condition. That numerical method allows to obtain instantaneous flow features and airfoil forces for different arrangements. It is validated first for unsteady motions of airfoils in oscillation and plunge. Then, steady airfoils cases are considered without plunging motion and a constant angle-of-attack. Comparisons with available experimental data are presented in terms of flow field and aerodynamic coefficients both for unsteady motions or steady airfoils. In particular, in order to show the possible improvement in the two-airfoil arrangement performance, the averaged lift coefficient is compared with the single-airfoil configuration. A discussion on the lift efficiency ratio with previous measurements and time development of the flow field permits to understand the mechanisms contributing to a positive interaction.

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The process of replacing an arbitrary Boolean function by a bijective one, a fundamental tool in reversible computing and in cryptography, is interpreted algebraically as a particular instance of a certain group homomorphism from the X-fold cartesian power of a group G into the automorphism group of the free G-set over the set X. It is shown that this construction not only can be generalized from groups to monoids but, more generally, to internal categories in arbitrary finitely complete categories where it becomes a cartesian isomorphism between certain discrete fibrations.

In this paper, an enhanced solid finite element formulation for rotor dynamics analysis is presented. The element kinematics is first defined with a Total Lagrangian formulation in order to account for possible centrifugal stiffening effect and its associated pre-stress deformation. The novelty of the three-dimensional element proposed in this study is then to correctly consider the effect of inertia due to small rotational deformation occurring around the pre-stressed equilibrium position. The rotational motion is characterized by interpolation of the translational degrees of freedom of the element. The accuracy and convergence of the proposed finite element are tested on several numerical examples consisting of a rotating rigid disk and a rotating Timoshenko beam with different slenderness ratios. All results agree well with analytical solutions excerpted from literature and demonstrate the usefulness and applicability of the proposed finite element formulation.

This article proposes to determine and identify the physical contributions that drive the internal resonance between the bending and torsion modes of a blade. The blade is modeled as a nonlinear beam including warping, twist and pre-bending, and a discretization scheme based on a Rayleigh-Ritz approximation is performed. The modal properties of the model are compared and validated using beam theory and finite element modeling. Several configurations of the model allowing the occurrence of an internal resonance between the first torsional and the second bending modes are considered. The frequency responses near the second bending mode are obtained through the Harmonic Balance Method coupled with a branch switching algorithm to locate and track bifurcated branches related to internal resonances. Attention is paid to the identification of the geometrical nonlinear terms that enable the appearance of an internal resonance. With the help of a multiple scale analysis, it is shown that it is essentially driven by a small set of coupling parameters involving bending and torsion displacements of the commensurate modes. It is also observed in a rotating situation thanks to the hardening of the bending mode.

International audience; A Design of Experiment method was applied combined with a performance prediction program to assess the influence of four design parameters on the propulsive capacity of kites used as auxiliary propulsion for merchant vessels. Those parameters are the lift coefficient, the lift to drag ratio or drag angle, the maximal load bearable by the kite and the ratio of the tether length on the square root of the kite area. These parameters are independent from the kite area and, therefore, they could be used with various kite ranges and types. The maximum wing load parameter is the one that shows the most influence on the propulsive force. Over 50% of the gains obtained through this study are directly attributable to it. Then the ratio of the tether length on the square root of the kite area comes as the second greatest influence factor for true wind angles above 70°. While the drag angle is more influential for the narrower angles. In fact, the most substantial gains are made upwind.

International audience; Eye movements are particularly important in aeronautics where operators rely on numerous sources of visual information. Eye-tracking reveals what we are looking at, but also the physical and psychological condition of an operator. The human perception, and more particularly the vision, is a vector of errors well known in human factors (tunnel effect, eye strain, etc.). The eyes can help finding where the attention is focused (gaze position), how the subject feels (fatigue), and interact with a system by eye movements [1]. Ocular interactions meet the need that HOTAS commands in aircraft are complexified by the high number of buttons and complex multiplexing. Oculometry has thus become a flagship sector of aeronautical research to understand human limits and interact more naturally with the system. Current solutions are largely based on video-based eye trackers, but this technology has some drawbacks: vibrations in the aircraft, visual field obstruction, and infrared illumination are signifiant issues that prevent eye trackers from being operational.

International audience; Over the past decade, interest in autonomous vessels significantly increased as the technology improved, especially in the automotive industry. Unlike cars, ships travel in a wild environment and maritime lanes are not limited by white lines. This makes the design of fully autonomous vessels even more challenging. Additionally, the need to reduce greenhouse gas emissions led to a renewed interest in wind propulsion. Sailboats have several advantages, such as full energy autonomy and a limited environmental impact. The Microtransat Challenge, which consists of crossing the Atlantic Ocean, is a tremendous test field. This paper describes, within that frame, a design procedure for the development of a robust fully autonomous sailboat to be deployed for long-term missions. In this paper, the mechanical and electronic design strategies are presented. A focus is on reliability and power management. Moreover, a test procedure for validating each design increment is described as well as a path plan that considers the risk of collision and weather routing with wind and currents. The Microtransat remains a challenge that no autonomous ship has ever succeeded (and has been completed by a single unmanned vessel, SB Met in 2018). However, the results by Breizh Tigresse and Sealeon in 2015 and 2018 made a step forward in terms of time and distance. They are presented and analyzed in this work

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International audience; A Hilbertian (co)algebra is defined as a (co)semigroup object in the monoidal category of Hilbert spaces. The carrier Hilbert space of such an algebra splits as an orthogonal direct sum of its Jacobson radical and the closure of the linear span of a special class of elements, the group-like elements of its adjoint coalgebra, which by the Riesz representation, correspond to closed maximal modular ideals. When the coproduct is isometric, semisimplicity is shown to be equivalent to the existence of adjoints in the sense of Ambrose’s H*-algebras. We also prove that the category of semisimple special Hilbertian algebras, that is, semisimple Hilbertian algebras with an isometric coproduct, i.e., essentially the algebras of the form l2(X) with the pointwise product, are dually equivalent to a subcategory of pointed sets and base-point preserving maps.

A topological commutative ring is said to be rigid when for every set $X$, the topological dual of the $X$-fold topological product of the ring is isomorphic to the free module over $X$. Examples are fields with a ring topology, discrete rings, and normed algebras. Rigidity translates into a dual equivalence between categories of free modules and of "topologically-free" modules and, with a suitable topological tensor product for the latter, one proves that it lifts to an equivalence between monoids in this category (some suitably generalized topological algebras) and coalgebras. In particular, we provide a description of its relationship with the standard duality between algebras and coalgebras, namely finite duality., This version only deals with the monoidalily of the equivalence

Before the final experimental validation and certification of a turbo-engine, designers perform a numerical simulation of its vibratory properties, among other things, in order to estimate its lifespan and adjust the design in an optimization process. One possible practical solution to decrease the vibratory response is to add underplatform dampers to the system. These components dissipate energy by friction and are widely employed in turbomachinery. However, a specific underplatform damper is usually efficient only for a specific mode. The purpose of this work is to investigate the possibility of adding different kinds of underplatform dampers to the cyclic structure in order to decrease the vibratory energy over a larger panel of modes. Different methods exist to determine the vibrations of nonlinear cyclic symmetric systems, but creating a robust methodology to account for the additional effect of mistuning remains a big challenge in the community. In this paper, the structure is mistuned through the friction coefficient of the dampers and not by altering its geometry, as is usually done in the literature. First, assuming a cyclic symmetric structure, the performance of the dampers is assessed for specific modes. Then, employing a method recently developed, the efficiency of an intentional mistuning pattern of underplatform dampers is studied and an optimal pattern proposed.