15,208 research outputs found
Inverse Demand Systems for Composite Liquid Assets: Evidence from China
This paper applies the concept of inverse demands and its related scale and substitution effects to model the demand for liquid assets in China. We also propose a new model, termed the Modified Almost Ideal Inverse Demand System (MAIIDS), which nests the Almost Ideal Inverse Demand System (AIIDS) as a special case. We estimate this new model and its special case by using Chinese panel data and find it statistically superior to the AIIDS. Results also reveal the improved regularity features of the MAIIDS, and show that demand patterns of liquid assets across different income groups in China are distinctive.AIIDS; MAIIDS; Regularity; Liquid assets.
Modulating Image Restoration with Continual Levels via Adaptive Feature Modification Layers
In image restoration tasks, like denoising and super resolution, continual
modulation of restoration levels is of great importance for real-world
applications, but has failed most of existing deep learning based image
restoration methods. Learning from discrete and fixed restoration levels, deep
models cannot be easily generalized to data of continuous and unseen levels.
This topic is rarely touched in literature, due to the difficulty of modulating
well-trained models with certain hyper-parameters. We make a step forward by
proposing a unified CNN framework that consists of few additional parameters
than a single-level model yet could handle arbitrary restoration levels between
a start and an end level. The additional module, namely AdaFM layer, performs
channel-wise feature modification, and can adapt a model to another restoration
level with high accuracy. By simply tweaking an interpolation coefficient, the
intermediate model - AdaFM-Net could generate smooth and continuous restoration
effects without artifacts. Extensive experiments on three image restoration
tasks demonstrate the effectiveness of both model training and modulation
testing. Besides, we carefully investigate the properties of AdaFM layers,
providing a detailed guidance on the usage of the proposed method.Comment: Accepted by CVPR 2019 (oral); code is available:
https://github.com/hejingwenhejingwen/AdaF
Fredholm conditions on non-compact manifolds: theory and examples
We give explicit Fredholm conditions for classes of pseudodifferential
operators on suitable singular and non-compact spaces. In particular, we
include a "user's guide" to Fredholm conditions on particular classes of
manifolds including asymptotically hyperbolic manifolds, asymptotically
Euclidean (or conic) manifolds, and manifolds with poly-cylindrical ends. The
reader interested in applications should be able read right away the results
related to those examples, beginning with Section 5. Our general, theoretical
results are that an operator adapted to the geometry is Fredholm if, and only
if, it is elliptic and all its limit operators, in a sense to be made precise,
are invertible. Central to our theoretical results is the concept of a Fredholm
groupoid, which is the class of groupoids for which this characterization of
the Fredholm condition is valid. We use the notions of exhaustive and strictly
spectral families of representations to obtain a general characterization of
Fredholm groupoids. In particular, we introduce the class of the so-called
groupoids with Exel's property as the groupoids for which the regular
representations are exhaustive. We show that the class of "stratified
submersion groupoids" has Exel's property, where stratified submersion
groupoids are defined by glueing fibered pull-backs of bundles of Lie groups.
We prove that a stratified submersion groupoid is Fredholm whenever its
isotropy groups are amenable. Many groupoids, and hence many pseudodifferential
operators appearing in practice, fit into this framework. This fact is explored
to yield Fredholm conditions not only in the above mentioned classes, but also
on manifolds that are obtained by desingularization or by blow-up of singular
sets
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