36,982 research outputs found
Production and nutritional composition of two annual ryegrass cultivars (Diploid and Tetraploid)
The feed cost represents the major cost in milk production. Direct grazing and forage produced on the dairy farm could allow the farmer to a better feed production cost control. Ryegrass have been extensively used for grazing and forage production. This study evaluates the production and nutritional composition of two ryegrass cultivars diploid and tetraploid alone or in a binary mixture (50:50). The results showed that the binary mixture is a good option because of its higher production of DM/ha, higher ME and NFC and lower content of NDF, ADF and ADL.info:eu-repo/semantics/publishedVersio
Share the Fame or Share the Blame? The Reputational Implications of Partnerships
We use an adverse selection model to study the dynamics of ?rms?reputations when ?rms implement joint projects. We show that in contrast with projects implemented by a single ?rm, in the case of joint projects a ?rm?s reputation does not necessarily increase following a success and does not necessarily decrease following a failure. We also study how reputation considerations a¤ect ?rms? decisions to participate in joint projects. We show that a high quality partner may not be preferable to a low quality partner, and that a high reputation partner is not necessarily preferable to a low reputation partner. JEL codes: L14, L15, L24, D82, D85
Local quantum ergodic conjecture
The Quantum Ergodic Conjecture equates the Wigner function for a typical
eigenstate of a classically chaotic Hamiltonian with a delta-function on the
energy shell. This ensures the evaluation of classical ergodic expectations of
simple observables, in agreement with Shnirelman's theorem, but this putative
Wigner function violates several important requirements. Consequently, we
transfer the conjecture to the Fourier transform of the Wigner function, that
is, the chord function. We show that all the relevant consequences of the usual
conjecture require only information contained within a small (Planck) volume
around the origin of the phase space of chords: translations in ordinary phase
space. Loci of complete orthogonality between a given eigenstate and its nearby
translation are quite elusive for the Wigner function, but our local conjecture
stipulates that their pattern should be universal for ergodic eigenstates of
the same Hamiltonian lying within a classically narrow energy range. Our
findings are supported by numerical evidence in a Hamiltonian exhibiting soft
chaos. Heavily scarred eigenstates are remarkable counter-examples of the
ergodic universal pattern.Comment: 4 figure
Testing the Equivalence of Regular Languages
The minimal deterministic finite automaton is generally used to determine
regular languages equality. Antimirov and Mosses proposed a rewrite system for
deciding regular expressions equivalence of which Almeida et al. presented an
improved variant. Hopcroft and Karp proposed an almost linear algorithm for
testing the equivalence of two deterministic finite automata that avoids
minimisation. In this paper we improve the best-case running time, present an
extension of this algorithm to non-deterministic finite automata, and establish
a relationship between this algorithm and the one proposed in Almeida et al. We
also present some experimental comparative results. All these algorithms are
closely related with the recent coalgebraic approach to automata proposed by
Rutten
Radiative corrections in bumblebee electrodynamics
We investigate some quantum features of the bumblebee electrodynamics in flat
spacetimes. The bumblebee field is a vector field that leads to a spontaneous
Lorentz symmetry breaking. For a smooth quadratic potential, the massless
excitation (Nambu-Goldstone boson) can be identified as the photon, transversal
to the vacuum expectation value of the bumblebee field. Besides, there is a
massive excitation associated with the longitudinal mode and whose presence
leads to instability in the spectrum of the theory. By using the
principal-value prescription, we show that no one-loop radiative corrections to
the mass term is generated. Moreover, the bumblebee self-energy is not
transverse, showing that the propagation of the longitudinal mode can not be
excluded from the effective theory.Comment: Revised version: contains some more elaborated interpretation of the
results. Conclusions improve
A percolation system with extremely long range connections and node dilution
We study the very long-range bond-percolation problem on a linear chain with
both sites and bonds dilution. Very long range means that the probability
for a connection between two occupied sites at a distance
decays as a power law, i.e. when , and
when . Site dilution means that the occupancy probability of a site
is . The behavior of this model results from the competition
between long-range connectivity, which enhances the percolation, and site
dilution, which weakens percolation. The case with is
well-known, being the exactly solvable mean-field model. The percolation order
parameter is investigated numerically for different values of
, and . We show that in the ranges
and the percolation order parameter depends only on
the average connectivity of sites, which can be explicitly computed in
terms of the three parameters , and
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