122 research outputs found
Configurations of social media-enabled strategies for open innovation, firm performance, and their barriers to adoption
The use of social media offers tremendous innovation potential. Yet, while current research emphasizes success stories, little is known about how firms can leverage the full potential of their social media use for open innovation. In this paper, the authors address this gap by conducting a configurational analysis to develop an integrative taxonomy of social media-enabled strategies for open innovation. This analysis stems from the integration of internal and external variables such as social media communication activities, organizational innovation seekers, potential innovation providers, the stages of the open innovation process, and their relationship with different performance outcomes and barriers to social media adoption for open innovation. Through an empirical study of 337 firms based in eight countries, four clusters have been identified that are characterized as distinct strategies: “marketing semi-open innovators,” “cross-department semi-open innovators,” “cross-department full process semi-open innovators” and “broad adopters open innovators.” The findings reveal the trade-offs associated with different strategies for implementing social media for open innovation and provide insights of the use of these strategies. By doing so, they suggest a more nuanced approach that contrasts with the traditionally positive (or even rosy) depiction of the effects of social media on open innovation. Accordingly, managers are encouraged to contemplate their organizational competencies, capabilities, and their strategic intent when drafting social media strategies for open innovation. Selective approaches, along with greater adoption leading to greater benefits, are shown to be more rewarding than a middle way that spreads things too thin. Avenues for further research include qualitative explorations of the trajectories unfolding through implementing social media strategies for innovation activities and the use of objective performance measures rather than subjective perceptions from informants to understand the complex relationships between social media adoption and performance.publishedVersionPeer reviewe
Analysis by x-ray microtomography of a granular packing undergoing compaction
Several acquisitions of X-ray microtomography have been performed on a beads
packing while it compacts under vertical vibrations. An image analysis allows
to study the evolution of the packing structure during its progressive
densification. In particular, the volume distribution of the pores reveals a
large tail, compatible to an exponential law, which slowly reduces as the
system gets more compact. This is quite consistent, for large pores, with the
free volume theory. These results are also in very good agreement with those
obtained by a previous numerical model of granular compaction.Comment: 4 pages, 4 figures. Latex (revtex4). to be published in Phys. Rev.
A constitutive law for dense granular flows
A continuum description of granular flows would be of considerable help in
predicting natural geophysical hazards or in designing industrial processes.
However, the constitutive equations for dry granular flows, which govern how
the material moves under shear, are still a matter of debate. One difficulty is
that grains can behave like a solid (in a sand pile), a liquid (when poured
from a silo) or a gas (when strongly agitated). For the two extreme regimes,
constitutive equations have been proposed based on kinetic theory for
collisional rapid flows, and soil mechanics for slow plastic flows. However,
the intermediate dense regime, where the granular material flows like a liquid,
still lacks a unified view and has motivated many studies over the past decade.
The main characteristics of granular liquids are: a yield criterion (a critical
shear stress below which flow is not possible) and a complex dependence on
shear rate when flowing. In this sense, granular matter shares similarities
with classical visco-plastic fluids such as Bingham fluids. Here we propose a
new constitutive relation for dense granular flows, inspired by this analogy
and recent numerical and experimental work. We then test our three-dimensional
(3D) model through experiments on granular flows on a pile between rough
sidewalls, in which a complex 3D flow pattern develops. We show that, without
any fitting parameter, the model gives quantitative predictions for the flow
shape and velocity profiles. Our results support the idea that a simple
visco-plastic approach can quantitatively capture granular flow properties, and
could serve as a basic tool for modelling more complex flows in geophysical or
industrial applications.Comment: http://www.nature.com/nature/journal/v441/n7094/abs/nature04801.htm
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