13,715 research outputs found
Implications of skill-biased technological change: international evidence
Demand for less skilled workers decreased dramatically in the US and in other developed countries over the past two decades. WE argue that pervasive skill-biased technological change, rather than increased trade with the development world, is the principal culprit. The pervasiveness of this technological change is important for two reasons. Firstly, it is an immediate and testable implication of technological change. Secondly, under standard assumptions, the more pervasive the skill-biased technological, the greater the increase in the embodied supply of less skilled workers and the greater the increase in the embodied supply if less skilled workers and the greater the increases in the embodied supply of less skilled workers and the greater the depressing effect on their relative wages through world goods prices. In contrast, in the Heckscher-Ohlin model with small open economies the skill-bias of local technological changes does not affect wages. Thus, pervasiveness deals with a major criticism of skill-biased technological as a cause. Testing the implications of pervasive, skill-biased technological change, we find strong supporting evidence. Firstly, across the OECD, most industries have increased the proportion of skilled workers employed, despite rising or stable relative wages. Secondly, increases in demand for skills were concentrated in the same manufacturing industries in different developed countries
Implications of Skill-Biased Technological Change: International Evidence
Demand for less skilled workers decreased dramatically in the US and in other developed countries over the past two decades. WE argue that pervasive skill-biased technological change, rather than increased trade with the development world, is the principal culprit. The pervasiveness of this technological change is important for two reasons. Firstly, it is an immediate and testable implication of technological change. Secondly, under standard assumptions, the more pervasive the skill-biased technological, the greater the increase in the embodied supply of less skilled workers and the greater the increase in the embodied supply if less skilled workers and the greater the increases in the embodied supply of less skilled workers and the greater the depressing effect on their relative wages through world goods prices. In contrast, in the Heckscher-Ohlin model with small open economies the skill-bias of local technological changes does not affect wages. Thus, pervasiveness deals with a major criticism of skill-biased technological as a cause. Testing the implications of pervasive, skill-biased technological change, we find strong supporting evidence. Firstly, across the OECD, most industries have increased the proportion of skilled workers employed, despite rising or stable relative wages. Secondly, increases in demand for skills were concentrated in the same manufacturing industries in different developed countries.
Spectrum of light scattering from an extended atomic wave packet
The spectrum of the light scattered from an extended atomic wave packet is
calculated. For a wave packet consisting of two spatially separated peaks
moving on parallel trajectories, the spectrum contains Ramsey-like fringes that
are sensitive to the phase difference between the two components of the wave
packet. Using this technique, one can establish the mutual coherence of the two
components of the wave packet without recombining them.Comment: 4 page
Dynamical Stability and Quantum Chaos of Ions in a Linear Trap
The realization of a paradigm chaotic system, namely the harmonically driven
oscillator, in the quantum domain using cold trapped ions driven by lasers is
theoretically investigated. The simplest characteristics of regular and chaotic
dynamics are calculated. The possibilities of experimental realization are
discussed.Comment: 24 pages, 17 figures, submitted to Phys. Rev
Orthogonality relations for triple modes at dielectric boundary surfaces
We work out the orthogonality relations for the set of Carniglia-Mandel
triple modes which provide a set of normal modes for the source-free
electromagnetic field in a background consisting of a passive dielectric
half-space and the vacuum, respectively. Due to the inherent computational
complexity of the problem, an efficient strategy to accomplish this task is
desirable, which is presented in the paper. Furthermore, we provide all main
steps for the various proofs pertaining to different combinations of triple
modes in the orthogonality integral.Comment: 15 page
Microscopic Theory of Spontaneous Decay in a Dielectric
The local field correction to the spontanous dacay rate of an impurity source
atom imbedded in a disordered dielectric is calculated to second order in the
dielectric density. The result is found to differ from predictions associated
with both "virtual" and "real" cavity models of this decay process. However, if
the contributions from two dielectric atoms at the same position are included,
the virtual cavity result is reproduced.Comment: 12 Page
Fluctuating Fronts as Correlated Extreme Value Problems: An Example of Gaussian Statistics
In this paper, we view fluctuating fronts made of particles on a
one-dimensional lattice as an extreme value problem. The idea is to denote the
configuration for a single front realization at time by the set of
co-ordinates of the
constituent particles, where is the total number of particles in that
realization at time . When are arranged in the ascending order
of magnitudes, the instantaneous front position can be denoted by the location
of the rightmost particle, i.e., by the extremal value
. Due to interparticle
interactions, at two different times for a single front
realization are naturally not independent of each other, and thus the
probability distribution [based on an ensemble of such front
realizations] describes extreme value statistics for a set of correlated random
variables. In view of the fact that exact results for correlated extreme value
statistics are rather rare, here we show that for a fermionic front model in a
reaction-diffusion system, is Gaussian. In a bosonic front model
however, we observe small deviations from the Gaussian.Comment: 6 pages, 3 figures, miniscule changes on the previous version, to
appear in Phys. Rev.
An operating system for future aerospace vehicle computer systems
The requirements for future aerospace vehicle computer operating systems are examined in this paper. The computer architecture is assumed to be distributed with a local area network connecting the nodes. Each node is assumed to provide a specific functionality. The network provides for communication so that the overall tasks of the vehicle are accomplished. The O/S structure is based upon the concept of objects. The mechanisms for integrating node unique objects with node common objects in order to implement both the autonomy and the cooperation between nodes is developed. The requirements for time critical performance and reliability and recovery are discussed. Time critical performance impacts all parts of the distributed operating system; e.g., its structure, the functional design of its objects, the language structure, etc. Throughout the paper the tradeoffs - concurrency, language structure, object recovery, binding, file structure, communication protocol, programmer freedom, etc. - are considered to arrive at a feasible, maximum performance design. Reliability of the network system is considered. A parallel multipath bus structure is proposed for the control of delivery time for time critical messages. The architecture also supports immediate recovery for the time critical message system after a communication failure
The M five brane on a torus
The D-3 brane is examined from the point of view of the wrapped M-theory five
brane on a torus. In particular, the S-dual versions of the 3-brane are
identified as coming from different gauge choices of the auxiliary field that
is introduced in the PST description of the five brane world volume theory.Comment: 7 pages. To appear in proceedings of "Quantum aspects of gauge
theories, supergravity and unification", Corfu, September 1998, typos
correcte
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