15,280 research outputs found
Catalan's intervals and realizers of triangulations
The Stanley lattice, Tamari lattice and Kreweras lattice are three remarkable
orders defined on the set of Catalan objects of a given size. These lattices
are ordered by inclusion: the Stanley lattice is an extension of the Tamari
lattice which is an extension of the Kreweras lattice. The Stanley order can be
defined on the set of Dyck paths of size as the relation of \emph{being
above}. Hence, intervals in the Stanley lattice are pairs of non-crossing Dyck
paths. In a former article, the second author defined a bijection
between pairs of non-crossing Dyck paths and the realizers of triangulations
(or Schnyder woods). We give a simpler description of the bijection .
Then, we study the restriction of to Tamari's and Kreweras' intervals.
We prove that induces a bijection between Tamari intervals and minimal
realizers. This gives a bijection between Tamari intervals and triangulations.
We also prove that induces a bijection between Kreweras intervals and
the (unique) realizers of stack triangulations. Thus, induces a
bijection between Kreweras intervals and stack triangulations which are known
to be in bijection with ternary trees.Comment: 22 page
Convergence rates for density estimators of weakly dependent time series
Assuming that is a vector valued time series with a common
marginal distribution admitting a density , our aim is to provide a wide
range of consistent estimators of . We consider different methods of
estimation of the density as kernel, projection or wavelets ones. Various cases
of weakly dependent series are investigated including the Doukhan & Louhichi
(1999)'s -weak dependence condition, and the -dependence of
Dedecker & Prieur (2005). We thus obtain results for Markov chains, dynamical
systems, bilinear models, non causal Moving Average... From a moment inequality
of Doukhan & Louhichi (1999), we provide convergence rates of the term of error
for the estimation with the \L^q loss or almost surely, uniformly on compact
subsets
S-Packing Colorings of Cubic Graphs
Given a non-decreasing sequence of positive
integers, an {\em -packing coloring} of a graph is a mapping from
to such that any two vertices with color
are at mutual distance greater than , . This paper
studies -packing colorings of (sub)cubic graphs. We prove that subcubic
graphs are -packing colorable and -packing
colorable. For subdivisions of subcubic graphs we derive sharper bounds, and we
provide an example of a cubic graph of order which is not
-packing colorable
Contribution of studies of sub-seismic fracture populations to paleo-hydrological reconstructions (Bighorn Basin, USA)
This work reports on the reconstruction of the paleo-hydrological history of the Bighorn Basin (Wyoming, USA) and illustrates the advantages and drawbacks of using sub-seismic diffuse fracture populations (i.e., micrometric to metric joints and veins forming heterogeneous networks), rather than fault zones, to characterize paleo-fluid systems at both fold and basin scales. Because sub-seismic fractures reliably record the successive steps of deformation of folded rocks, the analysis of the geochemical signatures of fluids that precipitated in these fractures reveals the paleo-fluid history not only during, but also before and after, folding. The present study also points out the need for considering pre-existing fluid systems and basin-scale fluid migrations to reliably constrain the evolution of fluid systems in individual folds
Validity of the one-dimensional limp model for porous materials
A straightforward criterion to determine the limp model validity for porous
materials is addressed here. The limp model is an "equivalent fluid" model
which gives a better description of the porous behavior than the well known
"rigid frame" model. It is derived from the poroelastic Biot model assuming
that the frame has no bulk stiffness. A criterion is proposed to identify the
porous materials for which the limp model can be used. It relies on a new
parameter, the Frame Stiffness Influence FSI based on porous material
properties. The critical values of FSI under which the limp model can be used,
are determined using a 1D analytical modeling for a specific boundary set:
radiation of a vibrating plate covered by a porous layer.Comment: 12th International Student Conference on Electrical Engineering,
Prague : Tch\`eque, R\'epublique (2008
Is the Collective Model of Labor Supply Useful for Tax Policy Analysis? A Simulation Exercise
The literature on household behavior contains hardly any empirical research on the within-household distributional effect of tax-benefit policies. We simulate this effect in the framework of a collective model of labor supply when shifting from a joint to an individual taxation system in France. We show that the net-of-tax relative earning potential of the wife is a significant determinant of intrahousehold negotiation but with very low elasticity. Consequently, the labor supply responses to the reform are entirely driven by the traditional substitution and income effects as in a unitary model. For some households only, the reform alters the intrahousehold distribution in a way that tends to change normative conclusions. A sensitivity analysis shows that the collective model would be required if the tax reform was both radical and of extended scope.Collective Model, Intrahousehold Allocation, Household Labor Supply, Tax Reform
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