13,523 research outputs found
Production Sharing and Comparative Advantage: The Cases of East Asia and Mexico
The industrial structures and strategy of the country, which exports parts and components, seem to have a significant effect on the pattern of production sharing of the country where assembly takes place. In the case of some East Asian countries, the pattern and the competitiveness in the assembly of final products strongly depends on the industrial structure and production sharing strategy of Japan. However, the relationship between Mexico and the United States seems to be completely different in that the pattern of production sharing of the first has little relationship with the export pattern of the second of parts and components. This difference may be explained through the difference between the United States and Japan in terms of the pattern of production sharing. Japan’s production sharing is based on specialization, whereas the production sharing of the United States is based on intra-industrial trade.production sharing, parts and components, revealed comparative advantage
Invariant submanifolds for affine control systems
Given an affine control system we present an algorithmic process of
construction of submanifolds that are invariant under controls assuming that
the linear span of has constant rank. We use the method
of reduction of Pfaffian systems to a largest integrable subsystem and finding
the first integrals and the generalized first integrals for the vector fields.Comment: 11 page
Demonstration of dispersive rarefaction shocks in hollow elliptical cylinder chains
We report an experimental and numerical demonstration of dispersive
rarefaction shocks (DRS) in a 3D-printed soft chain of hollow elliptical
cylinders. We find that, in contrast to conventional nonlinear waves, these DRS
have their lower amplitude components travel faster, while the higher amplitude
ones propagate slower. This results in the backward-tilted shape of the front
of the wave (the rarefaction segment) and the breakage of wave tails into a
modulated waveform (the dispersive shock segment). Examining the DRS under
various impact conditions, we find the counter-intuitive feature that the
higher striker velocity causes the slower propagation of the DRS. These unique
features can be useful for mitigating impact controllably and efficiently
without relying on material damping or plasticity effects
BPS D-branes from an Unstable D-brane
We search for exact tachyon kink solutions of DBI type effective action
describing an unstable D-brane with worldvolume gauge field turned in both the
flat and a curved background. There are various kinds of solutions in the
presence of electromagnetic fields in the flat space, such as periodic arrays,
topological tachyon kinks, half kinks, and bounces. We identify a BPS object,
D(-1)F1 bound state, which describes a thick brane with string flux density.
The curved background of interest is the ten-dimensional lift of the
Salam-Sezgin vacuum and, in the asymptotic limit, it approaches . The solutions in the curved
background are identified as composites of lower-dimensional D-branes and
fundamental strings, and, in the BPS limit, they become a D4D2F1 composite
wrapped on where is inside .Comment: 4 pages, to appear in the proceeding of PASCOS 2005, Gyeongju, Korea,
May 30-June 4, 200
Quasi-Normal Modes of a Natural AdS Wormhole in Einstein-Born-Infeld Gravity
We study the matter perturbations of a new AdS wormhole in (3+1)-dimensional
Einstein-Born-Infeld gravity, called "natural wormhole", which does not require
exotic matters. We discuss the stability of the perturbations by numerically
computing the quasi-normal modes (QNMs) of a massive scalar field in the
wormhole background. We investigate the dependence of quasi-normal frequencies
on the mass of scalar field as well as other parameters of the wormhole. It is
found that the perturbations are always stable for the wormhole geometry which
has the general relativity (GR) limit when the scalar field mass m satisfies a
certain, tachyonic mass bound m^2 > m^2_* with m^2_* < 0, analogous to the
Breitenlohner-Freedman (BF) bound in the global-AdS space, m^2_BF = 3 Lambda/4.
It is also found that the BF-like bound m^2_* shifts by the changes of the
cosmological constant Lambda or angular-momentum number l, with a level
crossing between the lowest complex and pure-imaginary modes for zero angular
momentum l = 0. Furthermore, it is found that the unstable modes can also have
oscillatory parts as well as non-oscillatory parts depending on whether the
real and imaginary parts of frequencies are dependent on each other or not,
contrary to arguments in the literature. For wormhole geometries which do not
have the GR limit, the BF-like bound does not occur and the perturbations are
stable for arbitrary tachyonic and non-tachyonic masses, up to a critical mass
m^2_c > 0 where the perturbations are completely frozen.Comment: Added comments and references, Accepted in EPJ
Analysis of adaptive algorithms for an integrated communication network
Techniques were examined that trade communication bandwidth for decreased transmission delays. When the network is lightly used, these schemes attempt to use additional network resources to decrease communication delays. As the network utilization rises, the schemes degrade gracefully, still providing service but with minimal use of the network. Because the schemes use a combination of circuit and packet switching, they should respond to variations in the types and amounts of network traffic. Also, a combination of circuit and packet switching to support the widely varying traffic demands imposed on an integrated network was investigated. The packet switched component is best suited to bursty traffic where some delays in delivery are acceptable. The circuit switched component is reserved for traffic that must meet real time constraints. Selected packet routing algorithms that might be used in an integrated network were simulated. An integrated traffic places widely varying workload demands on a network. Adaptive algorithms were identified, ones that respond to both the transient and evolutionary changes that arise in integrated networks. A new algorithm was developed, hybrid weighted routing, that adapts to workload changes
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