6,986 research outputs found
Remarks on spectral gaps on the Riemannian path space
In this paper, we will give some remarks on links between the spectral gap of
the Ornstein-Uhlenbeck operator on the Riemannian path space with lower and
upper bounds of the Ricci curvature on the base manifold; this work was
motivated by a recent work of A. Naber on the characterization of the bound of
the Ricci curvature by analysis of path spaces
Estimation of Dynamic Mixed Double Factors Model in High Dimensional Panel Data
The purpose of this article is to develop the dimension reduction techniques
in panel data analysis when the number of individuals and indicators is large.
We use Principal Component Analysis (PCA) method to represent large number of
indicators by minority common factors in the factor models. We propose the
Dynamic Mixed Double Factor Model (DMDFM for short) to re ect cross section and
time series correlation with interactive factor structure. DMDFM not only
reduce the dimension of indicators but also consider the time series and cross
section mixed effect. Different from other models, mixed factor model have two
styles of common factors. The regressors factors re flect common trend and
reduce the dimension, error components factors re ect difference and weak
correlation of individuals. The results of Monte Carlo simulation show that
Generalized Method of Moments (GMM) estimators have good unbiasedness and
consistency. Simulation also shows that the DMDFM can improve prediction power
of the models effectively.Comment: 38 pages, 2 figure
Effect of sea quarks on the single-spin asymmetries in polarized pp collisions at RHIC
We calculate the single-spin asymmetries of
bosons produced in polarized pp collisions with the valence part of the up and
down quark helicity distributions modeled by the light-cone
quark-spectator-diquark model while the sea part helicity distributions of the
up and down quarks treated as parametrization. Comparing our results with those
from experimental data at RHIC, we find that the helicity distributions of sea
quarks play an important role in the determination of the shapes of
. It is shown that is sensitive to , while to intuitively. The experimental
data of the polarized structure functions and the sum of helicities are also
important to constrain the sizes of quark helicity distributions both for the
sea part and the valence part of the nucleon.Comment: 19 latex pages, 5 figures, final version for publicatio
Trade Liberalization and Trade Performance of Environmental Goods: Evidence from Asia-Pacific Economic Cooperation Members
In this article, we study the impact of trade liberalization, including reductions in both tariff and nontariff trade barriers, on environmental goods (EGs) exports. Using bilateral trade data from 20 Asia-Pacific Economic Cooperation members, we find that tariff reduction in an exporting country has a larger positive impact on its exports of EGs than tariff reduction in an importing country. Our results also show that a lower nontariff barrier in an importing country increases its imports of EGs. A considerable amount of heterogeneity also exists in subsample results based on countries’ income levels
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