16,302 research outputs found
Science in the Third Dimension of R&D
We study a Schumpeterian model of long-run growth with endogenous fertility and with three interacting dimensions of innovation. Scientific research is the fundamental dimension of innovation that creates new technological knowledge. This is allocated over new working prototypes in the horizontal dimension. New firms finance scientific research by obtaining the property rights of new working prototypes, and existing firms invest in developing the blueprint mode of working prototypes into the more productive modes of production in the vertical dimension. Balanced growth in the standards of living is fully endogenous without scale effects, and a new parameter, i.e., the elasticity of scientific knowledge with respect to existing collective scientific knowledge, nonlinearly accelerates long-run growth. With exogenous population growth, the model generates a semi-endogenous result due to the endogenously determined bound on technological opportunity.Science; Technology; Blueprints; R&D; Endogenous Fertility
From Wires to Cosmology
We provide a statistical framework for characterizing stochastic particle
production in the early universe via a precise correspondence to current
conduction in wires with impurities. Our approach is particularly useful when
the microphysics is uncertain and the dynamics are complex, but only
coarse-grained information is of interest. We study scenarios with multiple
interacting fields and derive the evolution of the particle occupation numbers
from a Fokker-Planck equation. At late times, the typical occupation numbers
grow exponentially which is the analog of Anderson localization for disordered
wires. Some statistical features of the occupation numbers show hints of
universality in the limit of a large number of interactions and/or a large
number of fields. For test cases, excellent agreement is found between our
analytic results and numerical simulations.Comment: v3: minor changes and references added; matches published version in
JCA
Quantifying Diachronic Variability: The 'Ain Difla rockshelter (Jordan) and the Evolution of Levantine Mousterian Technology
Condette Jean-François. RAYNAL Pierre, voir CHAUDRU de RAYNAL Pierre. In: , . Les recteurs d'académie en France de 1808 à 1940. Tome II, Dictionnaire biographique. Paris : Institut national de recherche pédagogique, 2006. p. 327. (Histoire biographique de l'enseignement, 12
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