Patent Office in innovation policy: Nobody's perfect

The number of patent applications and "bad" patents issued has been rising rapidly in recent years. Based on this trend, we study the overload problem within the Patent Office and its consequences on the firms' R&D incentives. We assume that the examination process of patent applications is imperfect, and that its quality is poorer under congestion. Depend- ing on policy instruments such as submission fees and the toughness of the non-obviousness requirement, the system may result in a high-R&D equilibrium, in which firms self-select in their patent applications, or in an equilibrium with low R&D, opportunistic patent applications and the issuance of bad patents. Multiple equilibria often coexist, which deeply undermines the effectiveness of policy instruments. We investigate the robustness of our conclusions as to how the value of patent protection is formalized, taking into consideration the introduction of a penalty system for rejected patent applications, as well as the role of commitment to a given IP protection policy.patent office ; patent quality ; congestion ; innovation

Patent Office in innovation policy: Nobody's perfect

The number of patent applications and "bad" patents issued has been rising rapidly in recent years. Based on this trend, we study the overload problem within the Patent Office and its consequences on the firms' R&D incentives. We assume that the examination process of patent applications is imperfect, and that its quality is poorer under congestion. Depend- ing on policy instruments such as submission fees and the toughness of the non-obviousness requirement, the system may result in a high-R&D equilibrium, in which firms self-select in their patent applications, or in an equilibrium with low R&D, opportunistic patent applications and the issuance of bad patents. Multiple equilibria often coexist, which deeply undermines the effectiveness of policy instruments. We investigate the robustness of our conclusions as to how the value of patent protection is formalized, taking into consideration the introduction of a penalty system for rejected patent applications, as well as the role of commitment to a given IP protection policy.Les nombres de demandes de brevets et de "mauvais" brevets accordés ont cru rapidement dans les années récentes. Partant de ce constat, nous étudions le problème de congestion dans le processus d'attribution des brevets et ses conséquences sur les incitations à la R&D pour les entreprises. Nous supposons que le processus d'examen des demandes est imparfait et que sa qualité se dégrade sous l'effet de la congestion. En fonction d'instruments tels que les droits de soumission et la sévérité du critère d'inventivité, le système peut conduire à un équilibre avec forte R&D dans lequel les entreprises s'auto-sélectionnent, ou un équilibre avec peu de R&D, des demandes opportunistes et la délivrance de mauvais brevets. Il y a souvent multiplicité d'équilibres, ce qui limite l'efficacité des instruments de contrôle. On montre comment les conclusions se modifient selon la formalisation de la valeur de la protection par brevet, selon qu'est prise en compte la possibilité de pénalités pour rejet de la demande et selon la force de l'engagement contenu dans la politique de protection des droits de propriété intellectuels

Changements temporels de l'abondance du lièvre d'Amérique et de l'écureuil roux le long de successions forestières après feu et après coupe

Ce mémoire évalue l'influence des perturbations naturelles et anthropiques sur l'utilisation de l'habitat par deux espèces animales. Nous avons comparé l'intensité d'utilisation de l'habitat par le lièvre d'Amérique (Lepus americanus) et par l'écureuil roux (Tamiasciurus hudsonicus) le long de deux chronoséquences de succession, l'une après feu (20-200 ans) et l'autre après coupe (20-80 ans), dans la forêt boréale du Nord-Est québécois. Nous avons également caractérisé les changements temporels de la végétation le long des chronoséquences. Nos résultats révèlent que le lièvre d'Amérique utilise préférentiellement les coupes et que le maximum d'utilisation de l'habitat par l'écureuil roux a lieu environ 20 ans plus tôt après coupe qu'après feu. Le développement plus rapide de la régénération du sapin baumier (Abies balsamea) après coupe qu'après feu pourrait partiellement expliquer ces différences. Ces résultats indiquent que la coupe à blanc ne reproduit pas parfaitement les effets du feu

Texture evolution during deep-drawing processes

peer reviewedThis paper presents a constitutive law based on Taylor’s model implemented in our non-linear finite element code LAGAMINE. The yield locus is only locally described and a particular interpolation method has been developed. This local yield locus model uses a discrete representation of the material’s texture. The interpolation method is presented and a deep-drawing application is simulated in order to show up the influence of the texture evolution during forming processes

Assessment of the enhanced assumed strain (eas) and the assumed natural strain (ans) techniques in the mechanical behavior of the SSH3D solid-shell element

This paper presents the recently developed SSH3D Solid-Shell element implemented in the home-made LAGAMINE finite element code. This element is based on the Enhanced Assumed Strain (EAS) technique and the Assumed Natural Strain (ANS) technique. These techniques permit to avoid locking problems even in very bad conditions (nearly incompressible materials, very thin elements conducting to large aspect ratios, distorted element geometry…). The EAS technique artificially introduces additional degrees of freedom (DOFs) to the element. In the current configuration of the SSH3D element, up to 30 independent DOFs can be added to the 24 classical displacement DOFs (corresponding to the 3 displacements of the 8 element nodes). Contrarily to the nodal displacements, these additional DOFs are not linked between adjacent elements, so that they can be eliminated at the element level during the computation of the solution (before the assembling procedure). Nevertheless, they permit to increase the flexibility of the element which is very efficient for several locking issues. On the other hand, the ANS technique modifies the interpolation scheme for particular strain components. This technique is useful when shear and curvature locking problems are encountered. The ANS technique proved to eliminate the transverse shear locking from the element in bending dominated situations. In the current configuration of the element, four different versions of the ANS technique were implemented in the SSH3D element. Besides, a numerical integration scheme dedicated to Solid-Shell elements was implemented. It uses a user-defined number of integration points along the thickness direction, which permits to increase the element accuracy with a mesh containing a reduced number of elements along the thickness direction. In Sections 2, 3 and 4, the main features of the SSH3D element, i.e. the EAS technique, the ANS technique and the integration scheme are briefly described. Then, in this study, the quality of the element results is assessed in different applications. The effects of the EAS technique and the integration scheme on the volumetric locking and the effects of the ANS technique on the bending behavior of the element are analyzed in Sections 5 and 6

Diversity in Teams: Collaboration and Performance in Experiments with Different Tasks

We run two field experiments on team diversity in a large undergraduate economics class. Small groups with random compositions are generated and assigned team tasks. In the first experiment, tasks are creative and complex, while in the second one they are more standard. We use a multidimensional measure of diversity based on gender, race, and migration status. We estimate its impact on teamwork quality and group performance. We find a significant U-shaped effect on teamwork quality in both experiments. However, the impact on performance depends on the type of task: it is positive for creative tasks, but negative for standard ones. We interpret these results as the consequence of two conflicting forces: diversity is a source of creativity, but it can hamper communication and coordination between team members. When tasks are creative, the first (positive) force dominates; for standard tasks, instead, communication challenges do. The U-shaped impact on teamwork quality suggests that faultlines – dividing lines that split a group into subgroups based on demographic characteristics – can cause inter-subgroup cohesion to break down, while very homogeneous or very heterogeneous groups collaborate better. These results allow us to build a comprehensive framework to better understand the impact of diversity on teamwork

Modélisation de l'endommagement de fluage-fatigue d'un alliage de Nickel pour récepteur solaire

Un modèle élasto-visco-plastique basé sur le modèle de Chaboche a été implémenté afin de modéliser le comportement de tubes en alliage de nickel utilisés dans les centrales solaires à tour. Pour pouvoir estimer la durée de vie des tubes, un modèle d’endommagement basé sur les travaux de Lemaitre a également été intégré au code. Ce modèle comprend deux types d’endommagement qui sont cumulés : l’endommagement de fluage, dont l’évolution suit le modèle de Kachanov, et l’endommagement de fatigue dont l’évolution suit le modèle d’endommagement unifié de Lemaitre. Le modèle a été vérifié à partir de données expérimentales issues de la littérature.SOLAR PERFOR

Plant RNases T2, but not Dicer-like proteins, are major players of tRNA-derived fragments biogenesis

RNA fragments deriving from tRNAs (tRFs) exist in all branches of life and the repertoire of their biological functions regularly increases. Paradoxically, their biogenesis remains unclear. The human RNase A, Angiogenin, and the yeast RNase T2, Rny1p, generate long tRFs after cleavage in the anticodon region. The production of short tRFs after cleavage in the D or T regions is still enigmatic. Here, we show that the Arabidopsis Dicer-like proteins, DCL1-4, do not play a major role in the production of tRFs. Rather, we demonstrate that the Arabidopsis RNases T2, called RNS, are key players of both long and short tRFs biogenesis. Arabidopsis RNS show specific expression profiles. In particular, RNS1 and RNS3 are mainly found in the outer tissues of senescing seeds where they are the main endoribonucleases responsible of tRNA cleavage activity for tRFs production. In plants grown under phosphate starvation conditions, the induction of RNS1 is correlated with the accumulation of specific tRFs. Beyond plants, we also provide evidence that short tRFs can be produced by the yeast Rny1p and that, in vitro, human RNase T2 is also able to generate long and short tRFs. Our data suggest an evolutionary conserved feature of these enzymes in eukaryotes

A New Concept for Modeling Phase Transformations in Ti6Al4V Alloy Manufactured by Directed Energy Deposition

peer reviewedThe microstructure directly influences the subsequent mechanical properties of materials. In the manufactured parts, the elaboration processes set the microstructure features such as phase types or the characteristics of defects and grains. In this light, this article aims to understand the evolution of the microstructure during the directed energy deposition (DED) manufacturing process of Ti6Al4V alloy. It sets out a new concept of time-phase transformation-block (TTB). This innovative segmentation of the temperature history in different blocks allows us to correlate the thermal histories computed by a 3D finite element (FE) thermal model and the final microstructure of a multilayered Ti6Al4V alloy obtained from the DED process. As a first step, a review of the state of the art on mechanisms that trigger solid-phase transformations of Ti6Al4V alloy is carried out. This shows the inadequacy of the current kinetic models to predict microstructure evolution during DED as multiple values are reported for transformation start temperatures. Secondly, a 3D finite element (FE) thermal simulation is developed and its results are validated against a Ti6Al4V part representative of repair technique using a DED process. The building strategy promotes the heat accumulation and the part exhibits heterogeneity of hardness and of the nature and the number of phases. Within the generated thermal field history, three points of interest (POI) representative of different microstructures are selected. An in-depth analysis of the thermal curves enables distinguishing solid-phase transformations according to their diffusive or displacive mechanisms. Coupled with the state of the art, this analysis highlights both the variable character of the critical points of transformations, and the different phase transformation mechanisms activated depending on the temperature value and on the heating or cooling rate. The validation of this approach is achieved by means of a thorough qualitative description of the evolution of the microstructure at each of the POI during DED process. The new TTB concept is thus shown to provide a flowchart basis to predict the final microstructure based on FE temperature fields.IAWATHA; PDR T.0039.14 Lasercladdin

Impact of distortional hardening and the strength differential effect on the prediction of large deformation behavior of the Ti6Al4V alloy

peer reviewedThe ability of three plasticity models to predict the mechanical behavior of Ti6Al4V until fracture is presented. The first model is the orthotropic yield criterion CPB06 developed by Cazacu et al. (Int J Plast 22:1171–1194, 2006) with a distortional hardening, allowing for the description of material anisotropy and the strength differential effect. The second model is the anisotropic Hill’48 yield criterion with distortional hardening, describing the material anisotropy with quadratic functions but is unable to model the strength differential effect. Finally, the third model is the classical Hill’48 yield locus with isotropic hardening. Distortional hardening is modeled through five yield surfaces associated with five levels of plastic work. Each model is validated by comparing the finite element predictions with experimental results, such as the load and displacement field histories of specimens subjected to different stress triaxiality values. Tensile tests are performed on round bars with a V-notch, a through-hole, and two different radial notches; compression tests are performed on elliptical cross-section samples. The numerical results show that none of the models can perfectly predict both the measured load and the sample shape used for validation. However, the CPB06 yield criterion with distortional hardening minimizes the global error of the model predictions. The results provide a quantification of the influence of mechanical features such as hardening phenomenon, plastic anisotropy, and tension–compression asymmetry. The impact of these features on the prediction of the post-necking deformation behavior of the Ti6Al4V alloy is explored.Dommac