10,314 research outputs found
A Heckscher-Ohlin View of Sweden Competing in the Global Market
In this paper we explore the hypothesis that the Swedish malaise comes from the interaction of the Swedish welfare state with changes in the global marketplace. External commerce can expose Swedish workers in exporting and import-competing industries to competition from low-wage foreign workers that is incompatible with an extensive welfare system. The Heckscher-Ohlin theory that is the foundation of this paper allows a high-wage equilibrium without government intervention even though there is increasing competition from low-wage suppliers, if capital is abundant and if production is concentrated on the most capital intensive products. Then the unskilled workers can be employed at high wages either in the tradables or nontradables sector. However, Swedish investment rates have not been high enough to maintain the position that it had two decades ago. This we express in the form of the Heckscher-Ohlin Crowding Hypothesis: Swedish difficulties in its interactions with the global marketplace come from an eroding lead in capital abundance. Though losing its distinctiveness in capital abundance, Sweden remains well supplied with soft-wood forests. Although contributing substantially to GDP forest resources can also imply lower wages for unskilled workers and greater income inequality. A country with abundant forest resources and produce capital intensive products as well as pulp and paper, but a country with more moderate supplies of capital can find much of its capital deployed in pulp and paper and end up with a mix of tradables including relatively labor-intensive products. This product mix may dictate relatively low wages for unskilled workers since the marginal unskilled worker may be employed in sectors which globally award low wages.
Application of the diffraction trace formula to the three disk scattering system
The diffraction trace formula ({\em Phys. Rev. Lett.} {\bf 73}, 2304 (1994))
and spectral determinant are tested on the open three disk scattering system.
The system contains a generic and exponentially growing number of diffraction
periodic orbits. In spite of this it is shown that even the scattering
resonances with large imaginary part can be reproduced semiclassicaly. The
non-trivial interplay of the diffraction periodic orbits with the usual
geometrical orbits produces the fine structure of the complicated spectrum of
scattering resonances, which are beyond the resolution of the conventional
periodic orbit theory.Comment: Latex article + 3 ps figure
Constructing a partially transparent computational boundary for UPPE using leaky modes
In this paper we introduce a method for creating a transparent computational
boundary for the simulation of unidirectional propagation of optical beams and
pulses using leaky modes. The key element of the method is the introduction of
an artificial-index material outside a chosen computational domain and
utilization of the quasi-normal modes associated with such artificial
structure. The method is tested on the free space propagation of TE
electromagnetic waves. By choosing the material to have appropriate optical
properties one can greatly reduce the reflection at the computational boundary.
In contrast to the well-known approach based on a perfectly matched layer, our
method is especially well suited for spectral propagators.Comment: 32 pages, 19 figure
A Tensor-Based Dictionary Learning Approach to Tomographic Image Reconstruction
We consider tomographic reconstruction using priors in the form of a
dictionary learned from training images. The reconstruction has two stages:
first we construct a tensor dictionary prior from our training data, and then
we pose the reconstruction problem in terms of recovering the expansion
coefficients in that dictionary. Our approach differs from past approaches in
that a) we use a third-order tensor representation for our images and b) we
recast the reconstruction problem using the tensor formulation. The dictionary
learning problem is presented as a non-negative tensor factorization problem
with sparsity constraints. The reconstruction problem is formulated in a convex
optimization framework by looking for a solution with a sparse representation
in the tensor dictionary. Numerical results show that our tensor formulation
leads to very sparse representations of both the training images and the
reconstructions due to the ability of representing repeated features compactly
in the dictionary.Comment: 29 page
"Plug-and-Play" Edge-Preserving Regularization
In many inverse problems it is essential to use regularization methods that
preserve edges in the reconstructions, and many reconstruction models have been
developed for this task, such as the Total Variation (TV) approach. The
associated algorithms are complex and require a good knowledge of large-scale
optimization algorithms, and they involve certain tolerances that the user must
choose. We present a simpler approach that relies only on standard
computational building blocks in matrix computations, such as orthogonal
transformations, preconditioned iterative solvers, Kronecker products, and the
discrete cosine transform -- hence the term "plug-and-play." We do not attempt
to improve on TV reconstructions, but rather provide an easy-to-use approach to
computing reconstructions with similar properties.Comment: 14 pages, 7 figures, 3 table
An action for the super-5-brane in D=11 supergravity
An alternative path is taken for deriving an action for the supersymmetric
5-brane in 11 dimensions. Selfduality does not follow from the action, but is
consistent with the equations of motion for arbitrary supergravity backgrounds.
The action involves a 2-form as well as a 5-form world-volume potential;
inclusion of the latter makes the action, as well as the non-linear selfduality
relation for the 3-form field strength, polynomial. The requirement of
invariance under kappa-transformations determines the form of the selfduality
relation, as well as the action. The formulation is shown to be equivalent to
earlier formulations of 5-brane dynamics.Comment: plain tex, 8pp. Essential correction to the selfduality equation.
Added paragraph showing equivalence to other formulation
The Cost of Insecure Property Rights: R2 Revisited
In the conventional CAPM model only a single risk factor is considered. However, using a world market portfolio to estimate systematic risk in national portfolios little of the required rate of return is explained in developing as compared to developed countries. Adding a factor representing institutional risk the predictive power increases substantially. By stressing importance of property and investor rights in this fashion, we add to the research on international differences in R2 initiated by Morck et al. (2000). Our findings are consistent with the hypothesis that stock price synchronicy depends on the institutional quality.Asset pricing; International financial markets; Property rights; Financial economics
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