40,858 research outputs found
Does innovation stimulate employment? A firm-level analysis using comparable micro-data from four European countries
This paper studies the impact of process and product innovations introduced by firms on employment growth in these firms. A simple model that relates employment growth to process innovations and to the growth of sales separately due to innovative and unchanged products is developed and estimated using comparable firm-level data from France, Germany, Spain and the UK. Results show that displacement effects induced by productivity growth in the production of old products are large, while those associated with process innovations, which are likely to be compensated by price decreases, appear to be small. The effects related to product innovations are, however, strong enough to overcompensate these displacement
effects
Does innovation stimulate employment? A firm-level analysis using comparable micro data on four European countries
This paper studies the impact of process and product innovations introduced by firms
on their employment growth. A model that relates employment growth to process innovations
and to the growth of sales due to innovative and unchanged products is derived and
estimated using a unique source of comparable firm-level data from France, Germany,
Spain and the UK. Results for manufacturing show that, although process innovation
tends to displace employment, compensation effects are prevalent, and product innovation
is associated with employment growth. In the service sector there is less evidence of
displacement effects, and growth in sales of new products accounts for a non-negligible
proportion of employment growth. Overall the results are similar across countries, with
some interesting exceptions
Self-organized Criticality and Absorbing States: Lessons from the Ising Model
We investigate a suggested path to self-organized criticality. Originally,
this path was devised to "generate criticality" in systems displaying an
absorbing-state phase transition, but closer examination of the mechanism
reveals that it can be used for any continuous phase transition. We used the
Ising model as well as the Manna model to demonstrate how the finite-size
scaling exponents depend on the tuning of driving and dissipation rates with
system size.Our findings limit the explanatory power of the mechanism to
non-universal critical behavior.Comment: 5 pages, 2 figures, REVTeX
Computing Functions of Random Variables via Reproducing Kernel Hilbert Space Representations
We describe a method to perform functional operations on probability
distributions of random variables. The method uses reproducing kernel Hilbert
space representations of probability distributions, and it is applicable to all
operations which can be applied to points drawn from the respective
distributions. We refer to our approach as {\em kernel probabilistic
programming}. We illustrate it on synthetic data, and show how it can be used
for nonparametric structural equation models, with an application to causal
inference
The effect of constant darkness and short light periods on the survival and physiological fitness of two phytoplankton species and their growth potential after re-illumination
We tested the survival potential and fitness of two different algae strains (the diatom Thalassiosira weissflogii and the cryptophyceae Rhodomonas sp.) under different growth conditions (complete darkness and short light intervals, simulating conditions in a deep mixed water column) at different temperatures, plus the effect of these conditions on the physiological fitness and growth after re-illumination was examined. Both species survived the experimental conditions without significant cell loss or physiological damage. Two different survival strategies were observed: (1) the diatom T. weissflogii immediately reduced its metabolic rate and stopped cell division. The effect on chlorophyll a (chl-a) content and photosynthetic capacity was negligible. At 10 degrees C, T. weissflogii used the short light windows to metabolize carbohydrates and growth. (2) The cryptophyte Rhodomonas sp. initially continued to grow after transfer into all trials. However, the cell number decreased after day 6. Carbohydrate and chl-a content went on to decrease dramatically (70 and 50%, respectively). After 3 days of re-illumination, T. weissflogii grew faster than of Rhodomonas sp.. The diatom seemed to benefit from better start conditions and would out-compete the cryptophyte during a spring bloom. Our results highlight that these algae groups have different strategies in dealing with darkness, which potentially endow diatoms with a competitive advantage in deep mixed waters and in the season of early spring
Generalized (m,k)-Zipf law for fractional Brownian motion-like time series with or without effect of an additional linear trend
We have translated fractional Brownian motion (FBM) signals into a text based
on two ''letters'', as if the signal fluctuations correspond to a constant
stepsize random walk. We have applied the Zipf method to extract the
exponent relating the word frequency and its rank on a log-log plot. We have
studied the variation of the Zipf exponent(s) giving the relationship between
the frequency of occurrence of words of length made of such two letters:
is varying as a power law in terms of . We have also searched how
the exponent of the Zipf law is influenced by a linear trend and the
resulting effect of its slope. We can distinguish finite size effects, and
results depending whether the starting FBM is persistent or not, i.e. depending
on the FBM Hurst exponent . It seems then numerically proven that the Zipf
exponent of a persistent signal is more influenced by the trend than that of an
antipersistent signal. It appears that the conjectured law
only holds near . We have also introduced considerations based on the
notion of a {\it time dependent Zipf law} along the signal.Comment: 24 pages, 12 figures; to appear in Int. J. Modern Phys
Maximally entangled mixed states: Creation and concentration
Using correlated photons from parametric downconversion, we extend the
boundaries of experimentally accessible two-qubit Hilbert space. Specifically,
we have created and characterized maximally entangled mixed states (MEMS) that
lie above the Werner boundary in the linear entropy-tangle plane. In addition,
we demonstrate that such states can be efficiently concentrated, simultaneously
increasing both the purity and the degree of entanglement. We investigate a
previously unsuspected sensitivity imbalance in common state measures, i.e.,
the tangle, linear entropy, and fidelity.Comment: 4 pages, 3 figures, 1 table; accepted versio
Solid-solid phase equilibria in the NaCl-KCl system
Solid solutions, structurally ordered but compositionally disordered mixtures, can form for salts, metals, and even organic compounds. The NaCl-KCl system forms a solid solution at all compositions between 657 °C and 505 °C. Below a critical temperature of 505 °C, the system exhibits a miscibility gap with coexisting Na-rich and K-rich rocksalt phases. We calculate the phase diagram in this region using the semi-grand canonical Widom method, which averages over virtual particle transmutations. We verify our results by comparison with free energies calculated from thermodynamic integration and extrapolate the location of the critical point. Our calculations reproduce the experimental phase diagram remarkably well and illustrate how solid-solid equilibria and chemical potentials, including those at metastable conditions, can be computed for materials that form solid solutions
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