pinecone/core-2020-05-10-deduplication huggingface dataset:
Project leaders as team boundary spanners: Relational antecedents and performance outcomes

International audienceResearch has shown that NPD project leaders should engage in boundary-spanning activities. The present study tested the impact of four boundary-spanning activities on NPD project performance and analyzed the antecedents of these activities. We hypothesized that NPD project leaders' abilities to perform these activities depend on the characteristics of their personal networks -- structural holes, strength of ties, vertical and horizontal bridging ties. A Partial Least Squares test on 73 NPD projects showed that (a) "obtaining political support" and "scanning for ideas" are the boundary activities with the greatest impact on performance, (b) project leaders with strong ties in their network are more effective at these activities, (c) project leaders with structural holes in their networks are more effective in another boundary activity, "protecting the team", although this activity does not affect NPD outcomes. These results represent an important contribution to understanding how team leaders contribute to project performance
Mobile-to-mobile fading channels in amplify-and-forward relay systems under line-of-sight conditions: statistical modeling and analysis

Published version of an article from the journal:Annales des Telecommunications/Annals of Telecommunications. The original publication is available at Springerlink. http://dx.doi.org/10.1007/s12243-010-0169-zThis paper deals with the modeling and analysis of narrowband mobile-to-mobile (M2M) fading channels for amplify-and-forward relay links under line-of-sight (LOS) conditions. It is assumed that a LOS component exists in the direct link between the source mobile station (SMS) and the destination mobile station (DMS), as well as in the links via the mobile relay (MR). The proposed channel model is referred to as the multiple-LOS second-order scattering (MLSS) channel model. The MLSS channel model is derived from a second-order scattering process, where the received signal is modeled in the complex baseband as the sum of a single and a double scattered component. Analytical expressions are derived for the mean value, variance, probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades (ADF) of the received envelope of MLSS channels. The PDF of the channel phase is also investigated. It is observed that the LOS components and the relay gain have a significant influence on the statistics of MLSS channels. It is also shown that MLSS channels include various other channel models as special cases, e.g., double Rayleigh channels, double Rice channels, single-LOS double-scattering (SLDS) channels, non-line-of-sight (NLOS) second-order scattering (NLSS) channels, and single-LOS second-order scattering (SLSS) channels. The correctness of all analytical results is confirmed by simulations using a high performance channel simulator. Our novel MLSS channel model is of significant importance for the system level performance evaluation of M2M communication systems in different M2M propagation scenarios. Furthermore, our studies pertaining to the fading behavior of MLSS channels are useful for the design and development of relay-based cooperative wireless networks. © 2010 Institut Télécom and Springer-Verlag
Reward responsiveness in patients with chronic pain

Background: It is proposed that changes in reward processing in the
brain are involved in the pathophysiology of pain based on experimental
studies. The first aim of the present study was to investigate if reward
drive and/or reward responsiveness was altered in patients with chronic
pain (PCP) compared to controls matched for education, age and sex.
The second aim was to investigate the relationship between reward
processing and nucleus accumbens volume in PCP and controls. Nucleus
accumbens is central in reward processing and its structure has been
shown to be affected by chronic pain conditions in previous studies.
Methods: Reward drive and responsiveness were assessed with the
Behavioral Inhibition Scale/Behavioral Activation Scale, and nucleus
accumbens volumes obtained from T1-weighted brain MRIs obtained at
3T in 19 PCP of heterogeneous aetiologies and 20 age-, sex- and
education-matched healthy controls. Anhedonia was assessed with
Beck’s Depression Inventory II.
Results: The PCP group had significantly reduced scores on the reward
responsiveness, but not reward drive. There was a trend towards smaller
nucleus accumbens volume in the PCP compared to control group.
There was a significant positive partial correlation between reward
responsiveness and nucleus accumbens volume in the PCP group
adjusted for anhedonia, which was significantly different from the same
relationship in the control group.
Conclusions: Reward responsiveness is reduced in chronic pain
patients of heterogeneous aetiology, and this reduction was associated
with nucleus accumbens volume. Reduced reward responsiveness could
be a marker of chronic pain vulnerability, and may indicate reduced
opioid function.© 2015 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of  European Pain Federation - EFIC_. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are mad
Study of structural effect on Eu-substituted LSMO manganite for high temperature coefficient of resistance

n this work, Eu substituted La0.7Sr0.3MnO 3 (LSMO) is studied to achieve high temperature coefficient of resistance (TCR). The compounds La0.7-xEuxSr 0.3MnO3 with x=0, 0.1 0.2 and 0.3 are prepared by solid state reaction route and their structural and transport properties are examined by different characterization techniques. The metal-semiconductor/insulator transition temperature (TMI) decreases from 390 K (for x=0) to 240 K (for x=0.3) with decrease in average ionic radius 〈rA〉 of A-site. The maximum TCR percentage of La0.7-xEuxSr 0.3MnO3 compound is found to be increased for x=0.2 (1.9%) and for x=0.3 (3.36%) compared to its parent compound La0.7Sr 0.3MnO3 (1.1%). The substitution of Eu increases the lattice distortion, which enhances the TCR value from 1.1% to 3.36%. The robustness of distortion increases with decreasing 〈rA〉 which is well correlated with the high magneto-resistance, and high TCR findings
Deactivation and regeneration of Ni catalyst during steam reforming of model biogas: An experimental investigation

his paper presents detailed study of biogas reforming. Model biogas with different levels of H2S is subjected to reforming reaction over supported Ni catalyst in a fixed bed reactor at 700 °C and 800 °C. In order to understand the poisoning effects of H2S the reactions have been initially carried out without H2S in the feed stream. Three different H2S concentrations (20, 50 and 100 ppm) have been considered in the study. The H2O to CH4 ratio is maintained in such as way that CO2 also participates in the reforming reaction. After performing the poisoning studies, regeneration of the catalyst has been studied using three different techniques i) removal of H2S from the feed stream ii) temperature enhancement and iii) steam treatment. Poisoning at low temperature is not recoverable just by removal of H 2S from the feed stream. However, poisoning at high temperature is easily reversed just by removal of H2S from the feed stream. Unlike some previous reports by Li et al. (2010) and Rostrup-nielsen (1971) [1,2], catalyst regeneration is achieved in shorter time frames for all the regeneration techniques attempte
Pull-in analysis of non-uniform microcantilever beams under large deflection

Cantilever beams under the influence of electrostatic force form an important subclass of microelectromechanical system(MEMS) and nanoelectromechanical system. Most of the studies concerning these micro-nano resonators are centered around uniform cantilever beams. In this paper, we have investigated another class of micro-resonators consisting of non-uniform cantilever beams. The study is focused around investigating pull-in voltage and resonance frequency of non-uniform cantilever beams when they operate in the linear regime about different static equilibriums. In this paper, we term this frequency as “linear frequency.” Calculation of the linear frequency is done at different static equilibriums corresponding to different DC voltages. We have studied two classes of beams, one with increasing cross sectional area from the clamped edge (diverging beam) and other with decreasing cross sectional area from the clamped edge (converging beam). Within each class, we have investigated beams with linear as well as quartic variation in width. We start by obtaining Euler beam equation for non-uniform cantilever beams considering large deflection and their corresponding exact mode shapes from the linear equation. Subsequently, using the Galerkin method based on single mode approximation, we obtain static and dynamic modal equations for finding pull-in voltage and resonance frequency as a function of DC voltage, respectively. We found that the linear frequency of converging beams increases with increase in non-uniform parameter (α) while those of diverging beams decreases with α. A similar trend is observed for pull-in voltage. Within the converging class, beams with quartic variation in width show significant increase in both frequency and pull-in voltage as compared to corresponding linearly tapered beams. In quantitative terms, converging beams with quartic variation in width and α=−0.6 showed an increase in linear frequency by a factor of 2.5 times and pull-in voltage by 2 times as compared to commonly used uniform beams. Our investigation can prove to be a step forward in designing highly sensitive MEMS sensors and actuators
Nonparametric Estimation in a Multiplicative Censoring Model with Symmetric Noise

International audienceWe consider the model Yi = XiUi, i =1,. .. , n, where the Xi, the Ui and thus the Yi are all independent and identically distributed. The Xi have density f and are the variables of interest, the Ui are multiplicative noise with uniform density on [1-a, 1+a], for some 0 < a < 1, and the two sequences are independent. However, only the Yi are observed. We study nonparametric estimation of both the density f and the corresponding survival function. In each context, a projection estimator of an auxiliary function is built, from which estimator of the function of interest is deduced. Risk bounds in term of integrated squared error are provided, showing that the dimension parameter associated with the projection step has to perform a compromise. Thus, a model selection strategy is proposed in both cases of density and survival function estimation. The resulting estimators are proven to reach the best possible risk bounds. Simulation experiments illustrate the good performances of the estimators and a real data example is described
Simulation of human ischemic stroke in realistic 3D geometry

The authors would like to thank Christian Tenaud (LIMSI - CNRS) for providing the basis of the multi-resolution kernel of MR CHORUS, code that he developed at LIMSI for compressible Navier-Stokes equations.International audienceIn silico research in medicine is thought to reduce the need for expensive clinical trials under the condition of reliable mathematical models and accurate and efficient numerical methods. In the present work, we tackle the numerical simulation of reaction-diffusion equations modeling human ischemic stroke. This problem induces peculiar difficulties like potentially large stiffness which stems from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of steep spatial gradients in the reaction fronts, spatially very localized. Furthermore, simulations on realistic 3D geometries are mandatory in order to describe correctly this type of phenomenon. The main goal of this article is to obtain, for the first time, 3D simulations on realistic geometries and to show that the simulation results are consistent with those obtain in experimental studies or observed on MRI images in stroke patients. For this purpose, we introduce a new resolution strategy based mainly on time operator splitting that takes into account complex geometry coupled with a well-conceived parallelization strategy for shared memory architectures. We consider then a high order implicit time integration for the reaction and an explicit one for the diffusion term in order to build a time operator splitting scheme that exploits efficiently the special features of each problem. Thus, we aim at solving complete and realistic models including all time and space scales with conventional computing resources, that is on a reasonably powerful workstation. Consequently and as expected, 2D and also fully 3D numerical simulations of ischemic strokes for a realistic brain geometry, are conducted for the first time and shown to reproduce the dynamics observed on MRI images in stroke patients. Beyond this major step, in order to improve accuracy and computational efficiency of the simulations, we indicate how the present numerical strategy can be coupled with spatial adaptive multiresolution schemes. Preliminary results in the framework of simple geometries allow to assess the proposed strategy for further developments
Macroscopic rate equation modeling of trapping/detrapping of hydrogen isotopes in tungsten materials

International audienceCode development to solve numerically the model equations of diffusion and trapping of hydrogen in metals. Parametrization of the model trapping parameters (detrapping energies and density): fitting of experimental TDS spectrum. Confrontation model/experiment: evolution of retention with fluence and implantation temperature. Investigation of period of rest between implantation and TDS on retention and depth profile. a b s t r a c t Relevant parameters for trapping of Hydrogen Isotopes (HIs) in polycrystalline tungsten are determined with the MHIMS code (Migration of Hydrogen Isotopes in MaterialS) which is used to reproduce Thermal Desorption Spectrometry experiments. Three types of traps are found: two intrinsic traps (detrapping energy of 0.87 eV and 1.00 eV) and one extrinsic trap created by ion irradiation (detrapping energy of 1.50 eV). Then MHIMS is used to simulate HIs retention at different fluences and different implantation temperatures. Simulation results agree well with experimental data. It is shown that at 300 K the retention is limited by diffusion in the bulk. For implantation temperatures above 500 K, the retention is limited by trap creation processes. Above 600 K, the retention drops by two orders of magnitude as compared to the retention at 300 K. With the determined detrapping energies, HIs outgassing at room temperature is predicted. After ions implantation at 300 K, 45% of the initial retention is lost to vacuum in 300 000 s while during this time the remaining trapped HIs diffuse twice as deep into the bulk
Innovation and Knowledge Sharing Across Professional Boundaries: Political Interplay between Boundary Objects and Brokers.

International audienceThe article examines the process of innovation and knowledge sharing from a perspective that focuses on the influence that local circumstances can have. In particular, it looks at the problems of knowledge sharing between groups of professionals. It presents a comparative analysis of two studies, one involving two groups of IT professionals; the other a network of healthcare professionals. The data was collected in two sets. The first set consisted of the results from two earlier, independent studies; the second was collected specifically for this article. We investigate the role played by boundary objects and brokers. Through an analysis of the interplay between boundary object and broker, we uncover the dynamics of the innovation process and show that the role played by the broker can be political. We identify two strategies that are used by brokers in the selection of a boundary object. The first is directed towards achieving a balance between the actors involved and the second is directed towards controlling their activities. We conclude by suggesting that other researchers should also consider the interplay between broker and boundary object when examining cross-boundary knowledge sharing
Gamma Pegasi : testing Vega-like magnetic fields in B stars

International audienceContext. The bright B pulsator γ Peg shows both p and g modes of β Cep and SPB types. It has also been claimed that it is a magnetic star, while others do not detect any magnetic field.Aims. We check for the presence of a magnetic field, with the aim to characterise it if it exists, or else provide a firm upper limit of its strength if it is not detected. If γ Peg is magnetic as claimed, it would make an ideal asteroseismic target for testing various theoretical scenarios. If it is very weakly magnetic, it would be the first observation of an extension of Vega-like fields to early B stars. Finally, if it is not magnetic and we can provide a very low upper limit on its non-detected field, it would make an important result for stellar evolution models.Methods. We acquired high resolution, high signal-to-noise spectropolarimetric Narval data at Telescope Bernard Lyot (TBL). We also gathered existing dimaPol spectropolarimetric data from the Dominion Astrophysical Observatory (DAO) and Musicos spectropolarimetric data from TBL. We analysed the Narval and Musicos observations using the least-squares deconvolution (LSD) technique to derive the longitudinal magnetic field and Zeeman signatures in lines. The longitudinal field strength was also extracted from the Hβ line observed with the DAO. With a Monte Carlo simulation we derived the maximum strength of the field possibly hosted by γ Peg.Results. We find that no magnetic signatures are visible in the very high quality spectropolarimetric data. The average longitudinal field measured in the Narval data is Bl =  −0.1 ± 0.4 G. We derive a very strict upper limit of the dipolar field strength of Bpol ~ 40 G.Conclusions. We conclude that γ Peg is not magnetic: it hosts neither a strong stable fossil field as observed in a fraction of massive stars nor a very weak Vega-like field. There is therefore no evidence that Vega-like fields exist in B stars, contrary to the predictions by fossil field dichotomy scenarios. These scenarios should thus be revised. Our results also provide strong constraints for stellar evolution models
Using Surface Evolver to measure pressures and energies of real 2D foams submitted to quasi-static deformations

International audienceStatic 2D foams have the interesting property that their energy is measurable by summing up the length of their films, so that a simple optical picture of a 2D foam should enable measurement of its energy and other quantities such as its bubbles’ pressures. This operation is of course unrealizable in most experiments since the optical resolution limits the accuracy of length measurements. Here we show that, using image analysis tools alongside an iterative procedure based on the Surface Evolver (Brakke, 1992) to analyze optical images of a 2D foam, we are able to measure accurately its energy and its bubbles’ pressures up to a single multiplying factor. We determine this factor, and validate this procedure, by comparing experimental measurements of the pressure and the work done on a 2D foam experiencing a quasi-static localized deformation with the energy and pressures computed using our procedure
Ultra-high-reflectivity photonic-bandgap mirrors in a ridge SOI waveguide

International audienceMicrocavities consisting of two identical tapered mirrors etched into silicon-on-insulator ridge waveguides are investigated for operation at telecommunication wavelengths. They offer very small modal volumes of approximately 0.6 (λ/n)3 and calculated intrinsic Q factors of 400 000. We have measured a Q factor of 8900 for a loaded cavity, in agreement with the theoretical value. In contrast to recent works performed on suspended membranes, the buried SiO2 layer is not removed. The cavities possess strong mechanical robustness, thus making them attractive from the viewpoint of integration in large systems. The cavity Q factor is much larger than those previously obtained for similar geometries on a substrate
Intermittent collective dynamics emerge from conflicting imperatives in sheep herds

International audienceAmong the many fascinating examples of collective behavior exhibited by animal groups, some species are known to alternate slow group dispersion in space with rapid aggregation phenomena induced by a sudden behavioral shift at the individual level. We study this phenomenon quantitatively in large groups of grazing Merino sheep under controlled experimental conditions. Our analysis reveals strongly intermittent collective dynamics consisting of fast, avalanche-like regrouping events distributed on all experimentally accessible scales. As a proof of principle, we introduce an agent-based model with individual behavioral shifts, which we show to account faithfully for all collective properties observed. This offers, in turn, an insight on the individual stimulus/ response functions that can generate such intermittent behavior. In particular, the intensity of sheep allelomimetic behavior plays a key role in the group's ability to increase the per capita grazing surface while minimizing the time needed to regroup into a tightly packed configuration. We conclude that the emergent behavior reported probably arises from the necessity to balance two conflicting imperatives: (i) the exploration of foraging space by individuals and (ii) the protection from predators offered by being part of large, cohesive groups. We discuss our results in the context of the current debate about criticality in biology. sheep herds | collective behavior | self-organization | computational modeling | Allelomimetis
Miniaturized and reconfigurable notch antenna based on a BST ferroelectric thin film

International audienceThis work deals with the design, realization and characterization of a miniature and frequency agileantenna based on a ferroelectric Ba0,80Sr0,20TiO3 thinfilm. The notch antenna is loaded with a variablemetal/insulator/metal (MIM) capacitor and is achieved by a monolithic method. The MIM capacitance is3.7 pF, which results in a resonant frequency of 670 MHz compared to 2.25 GHz for the unloadedsimulated antenna; the resulting miniaturization rate is 70%. The characterization of the antennaprototype shows a frequency tunable rate of 14.5% under an electricfield of 375 kV/cm, with a tunabilityperformance h = 0.04