658 research outputs found
An organisational design approach of business environments: the case of Barcamps milieu in Paris
International audienceShifting business environment is often described as a decisive factor for organisational transformations. Various levels of organisation are proposed by the literature in order for an enterprise to be able to handle factors that outreach their boundaries. In this paper, we examine the case of Barcamps, a novel organisational pattern addressing issues beyond productivity and efficiency. We propose an analysis of its design parameters and functional requirements, contributing to the research and practice of organisational design beyond the boundaries of a specific organisation
Collision-induced Raman scattering from a pair of dissimilar particles: An intriguing mathematical model predicting the suppression of the odd-numbered partial waves
Relying on a simple analytic two-atom model in which the anisotropy of the interaction dipole polarizability obeys an inverse power law as a function of separation, we offer mathematical and numerical evidence that, in a monoatomic gas, the free-free Raman spectrum for a collisional pair of two different isotopes,aāaā², may vastly differ from that for aāa. This result is obtained even if a and aā² are assumed to have the same mass and zero nuclear spin and even if aāa and aāaā² are subject to the same interaction polarizability and potential. The mechanism responsible for this effect is inherent in the parity of the partial-wave rotational quantum number J: given that the contribution of each partial wave to the Raman cross section is controlled by a polarizability-transition matrix-element and that each of those matrix-elements has a radial component with a magnitude slightly smaller than that of the preceding partial wave, a deficit which disfavors the odd-numbered waves is accumulated upon summing over J. In the far high-frequency wing, this deficit tends to generate spectral intensities for aāaā² about half as great as the aāa ones, a tendency which becomes all the more effective as temperature is decreased. We show for instance that, for the spectral branch ĪJ = 2, the fractional difference between the free-free differential cross sections for aāa and aāaā² is 12(1āx2)31+3x412(1āx2)31+3x4, with x=E/Eā²āāāāāāx=E/Eā² (E (Eā²) being the initial (final) state energy of the pair and Eā² ā E = hcĪ½ (Ī½ > 0)). Remarkably, this quantity is zero at Ī½ ā 0 but goes to 1212 for Ī½ ā« 0. For ĪJ = 0, analogous conclusions may be drawn from the expression (1+ln(1+x1āx)2arctanx)ā1(1+ln(1+x1āx)2arctanx)ā1
Dirac bubble potential for HeāHe and inadequacies in the continuum: Comparing an analytic model with elastic collision experiments
We focus on the long-pending issue of the inadequacy of the Dirac bubble potential model in the description of HeāHe interactions in the continuum [L. L. Lohr and S. M. Blinder, Int. J. Quantum Chem. 53, 413 (1995)]. We attribute this failure to the lack of a potential wall to mimic the onset of the repulsive interaction at close range separations. This observation offers the explanation to why this excessively simple model proves incapable of quantitatively reproducing previous experimental findings of glory scattering in HeāHe, although being notorious for its capability of reproducing several distinctive features of the atomic and isotopic helium dimers and trimers [L. L. Lohr and S. M. Blinder, Int. J. Quantum Chem. 90, 419 (2002)]. Here, we show that an infinitely high, energy-dependent potential wall of properly calculated thickness rc(E) taken as a supplement to the Dirac bubble potential suffices for agreement with variable-energy elastic collision cross section experiments for 4Heā4He, 3Heā4He, and 3Heā3He [R. Feltgen et al., J. Chem. Phys. 76, 2360 (1982)]. In the very low energy regime, consistency is found between the Dirac bubble potential (to which our extended model is shown to reduce) and cold collision experiments [J. C. Mester et al., Phys. Rev. Lett. 71, 1343 (1993)]; this consistency, which in this regime lends credence to the Dirac bubble potential, was never noticed by its authors. The revised model being still analytic is of high didactical value while expected to increase in predictive power relative to other appraisals
Comment on āCCSD study of anharmonic Raman cross sections of fundamental, overtone, and combination transitionsā
Equations (36) and (37) in L. N. Vidal, P. A. M. Vazquez, Int. J. Quantum Chem. 2012, 112, 3205 are wrong. The agreement between theoretical and experimental Raman cross sections is greatly improved with use of the corrected expressions
A Comprehensive Performance Evaluation of Deformable Face Tracking "In-the-Wild"
Recently, technologies such as face detection, facial landmark localisation
and face recognition and verification have matured enough to provide effective
and efficient solutions for imagery captured under arbitrary conditions
(referred to as "in-the-wild"). This is partially attributed to the fact that
comprehensive "in-the-wild" benchmarks have been developed for face detection,
landmark localisation and recognition/verification. A very important technology
that has not been thoroughly evaluated yet is deformable face tracking
"in-the-wild". Until now, the performance has mainly been assessed
qualitatively by visually assessing the result of a deformable face tracking
technology on short videos. In this paper, we perform the first, to the best of
our knowledge, thorough evaluation of state-of-the-art deformable face tracking
pipelines using the recently introduced 300VW benchmark. We evaluate many
different architectures focusing mainly on the task of on-line deformable face
tracking. In particular, we compare the following general strategies: (a)
generic face detection plus generic facial landmark localisation, (b) generic
model free tracking plus generic facial landmark localisation, as well as (c)
hybrid approaches using state-of-the-art face detection, model free tracking
and facial landmark localisation technologies. Our evaluation reveals future
avenues for further research on the topic.Comment: E. Antonakos and P. Snape contributed equally and have joint second
authorshi
Exploring the sources of innovation: the case of Hackathon
This paper advances the exploration of the sources of innovation through the characteristics of the objects produced. To achieve a greater openness to the un- known of innovation processes, we choose not to examine final products. While, as put by von Hippel, final products embed in their functions a value (of use or of exchange), they hide the non-deterministic nature of the process, implying that the goal was known from the beginning. Instead, we will examine poten- tial products, that means projects that have not yet concluded to the market, neither have they been used. Investigating the contributions at a Hackathon hosted by Google, we induce three categories of innovative attitude: collective intimacy, entrepreneurial thinking and technological avant-garde
- ā¦