Reactive concurrent programming revisited

In this note we revisit the so-called reactive programming style, which evolves from the synchronous programming model of the Esterel language by weakening the assumption that the absence of an event can be detected instantaneously. We review some research directions that have been explored since the emergence of the reactive model ten years ago. We shall also outline some questions that remain to be investigated

Advanced constitutive modeling for application to sheet forming

Continuum constitutive descriptions of plasticity suitable for finite element simulations of sheet forming processes are succinctly discussed. Although multi-scale approaches allow for a more explicit representation of the physical deformation mechanisms occurring at microscopic scales, they are usually not suitable for industrial applications because of the quick turnaround time needed for process design simulations. Therefore, advances in classical concepts such as plastic anisotropy and strain hardening are still very much in demand. This article describes possible ways to make use of multi-scale results for application to sheet metal forming simulations.11Ysciescopu

Interacting Agents and Continuous Opinions Dynamics

We present a model of opinion dynamics in which agents adjust continuous opinions as a result of random binary encounters whenever their difference in opinion is below a given threshold. High thresholds yield convergence of opinions towards an average opinion, whereas low thresholds result in several opinion clusters. The model is further generalised to network interactions, threshold heterogeneity, adaptive thresholds and binary strings of opinions.Comment: 21 pages, 13 figures. http://www.lps.ens.fr/~weisbuch/contopidyn/contopidyn.htm

Thermodynamic modelling of P availability: the case of intercropping rhizosphere

Plants of chickpea and durum wheat were cultivated as sole-­‐crop and intercrop in a rhizobox deviceaccording to a substitutive design. Unplanted soil was used as a control treatment. The soil used was a noncarbonated Luvisol with a neutral pH. Plants were harvested at the chickpea flowering stage. The pH, Pavailability and dissolved Ca were measured in soil as extracted by water and CaCl2 (1 and 10 mM). A set ofthermodynamic models were used (i.e. CD MUSIC; Nica Donnan; ion exchange) to simulate and understandmeasured P availability variations in each treatment

The Effect of Spatial Design on User Memory Performance Using the Method of Loci in VR

Based on the Method of Loci, the following experiment compares the effect of two different virtual environments on participants' memory performance. The primary task consists of remembering a sequence of random playing cards. Each virtual environment is based on a different architectural style with a different layout. One is inspired by a Palladian style architecture, and the other by a Modern curved architecture

Observations on the Nonlinear Unloading Behavior of Advanced High Strength Steels

The unloading behavior was compared for three different steel grades: a dual-phase steel, a transformation-induced plasticity steel, and a twinning-induced plasticity steel. Steels that harden by phase transformation or deformation twinning exhibited a smaller component of microplastic strain during unloading and a smaller reduction in the chord modulus compared to the conventional hardening steel. As a result, unloading is closer to pure elastic unloading when the TRIP effect or TWIP effect is active.X111513sciescopu

Evaluation of constitutive models for springback prediction in U-draw/bending of DP and TRIP steel sheets

U-draw/bending experiments and simulations were performed to investigate the characteristics of springback in sheet metals. The finite element method is frequently used for the simulation of springback, but the predictions are strongly influenced by the constitutive models such as yield criteria and hardening laws. In the present study, springback of DP and TRIP steel sheets after U-draw/bending was predicted with a finite element analysis. Various yield functions were considered, namely, the isotropic von Mises and anisotropic Hill models. For strain hardening, isotropic, non-linear kinematic and combined isotropic-kinematic hardening models were considered. In order to characterize the isotropic hardening behavior, both uniaxial and balanced biaxial (hydraulic bulge) tension tests were carried out. For the characterization of the combined isotropic-kinematic hardening model, forward-reverse simple shear tests were conducted. The springback predictions were greatly influenced by the choice of the hardening model but slightly affected by the choice of the yield criterion. The kinematic hardening and combined isotropic-kinematic hardening models provided satisfactory predictions for DP590 and TRIP590 sheets, respectively. Due to an extended measurable strain range, the use of the flow curves from the hydraulic bulge test led to more reliable results than those of uniaxial tension.ope

Application of the Virtual Fields Method to determine dynamic properties at intermediate strain rates

Crash analysis simulation is now very important in automotive industry to assess automotive crashworthiness and safety. In order to acquire reliable crash simulation results, precise material behaviors at intermediate strain rates should be used as input data. To determine the stress-strain curves at various strain rates, the number of expensive and complicated experiments is large. The present study aims at determining the stress-strain curves of sheet metals at various strain rates from a single dynamic experiment. A new type of high speed tensile tester for sheet metal specimens was built and high speed tensile tests were carried out. Full-field heterogeneous strain fields were measured by a digital image correlation technique using a highspeed camera. The load data was acquired from strain gauges attached to the elastic deformation region on the specimen. Then, an inverse identification scheme with a rate dependent hardening law was applied to retrieve dynamic parameters. The stress-strain curves of advanced high strength steel at intermediate strain rates (100 /s - 300 /s) were successfully obtained from a single experiment.11Ysciescopu