5,388 research outputs found
Projections of Net Migration to the United States
[Excerpt] Immigration projections are subject to a large degree of uncertainty even in the near term. In fact, the two agencies\u27 projections for net migration in 2010 range, under plausible alternative assumptions, from as low as 150,000 to more than 1.5 million people. Analysis of historical data implies an 80 percent probability that over the next decade, net migration will average between about 500,000 and 1.5 million people annually, with the range of possible outcomes narrowing somewhat over a longer horizon. This paper examines the projection methodologies and outlines the most recent projections of the Social Security trustees and the Census Bureau. The trustees\u27 projections are higher than those of the Census Bureau in the near term but lower after 2025
Do rising labor costs trigger higher inflation?
The evidence that developments in compensation growth lead overall CPI inflation has thus far been inconclusive. This study, however, sheds new light on the relationship between labor costs and price inflation. By breaking down compensation and prices into their various components, the author finds that compensation growth in the service-producing segment of the private sector can help predict prices for a specific group of services.Inflation (Finance) ; Labor market ; Wages
On the Mapping of Time-Dependent Densities onto Potentials in Quantum Mechanics
The mapping of time-dependent densities on potentials in quantum mechanics is
critically examined. The issue is of significance ever since Runge and Gross
(Phys. Rev. Lett. 52, 997 (1984)) established the uniqueness of the mapping,
forming a theoretical basis for time-dependent density functional theory. We
argue that besides existence (so called v-representability) and uniqueness
there is an important question of stability and chaos. Studying a 2-level
system we find innocent, almost constant densities that cannot be constructed
from any potential (non-existence). We further show via a Lyapunov analysis
that the mapping of densities on potentials has chaotic regions in this case.
In real space the situation is more subtle. V-representability is formally
assured but the mapping is often chaotic making the actual construction of the
potential almost impossible. The chaotic nature of the mapping, studied for the
first time here, has serious consequences regarding the possibility of using
TDDFT in real-time settings
Guaranteed emergence of genuine entanglement in 3-qubit evolving systems
Multipartite entanglement has been shown to be of particular relevance for a
better understanding and exploitation of the dynamics and flow of entanglement
in multiparty systems. This calls for analysis aimed at identifying the
appropriate processes that guarantee the emergence of multipartite entanglement
in a wide range of scenarios. Here we carry on such analysis considering a
system of two initially entangled qubits, one of which is let to interact with
a third qubit according to an arbitrary unitary evolution. We establish
necessary and sufficient conditions on the corresponding Kraus operators, to
discern whether the evolved state pertains to either one of the classes of
3-qubit pure states that exhibit some kind of entanglement, namely biseparable,
W-, and GHZ- genuine entangled classes. Our results provide a classification of
the Kraus operators according to their capacity of producing 3-qubit
entanglement, and pave the way for extending the analysis to larger systems and
determining the particular interactions that must be implemented in order to
create, enhance and distribute entanglement in a specific manner.Comment: Two new subsections included. Accepted for publication in The
European Physical Journal
Six-degree-of-freedom program to optimize simulated trajectories (6D POST). Volume 1: Formulation manual
The basic equations and models used in a computer program (6D POST) to optimize simulated trajectories with six degrees of freedom were documented. The 6D POST program was conceived as a direct extension of the program POST, which dealt with point masses, and considers the general motion of a rigid body with six degrees of freedom. It may be used to solve a wide variety of atmospheric flight mechanics and orbital transfer problems for powered or unpowered vehicles operating near a rotating oblate planet. Its principal features are: an easy to use NAMELIST type input procedure, an integrated set of Flight Control System (FCS) modules, and a general-purpose discrete parameter targeting and optimization capability. It was written in FORTRAN 4 for the CDC 6000 series computers
Sleep Deprivation And Recovery: The Effects Of P300 Three And Six Hours Post Recovery
The P300 waveform is an auditory evoked potential (AEP) elicited through a decision making process. Due to the endogenous nature of the P300 response, which requires participants to actively respond to an auditory stimuli, it has been used as on objective measure to evaluate the cognitive processes of attention and memory. Previous studies have looked at the P300 before and after sleep deprivation as well as after brief rest periods. Evidence shows that a decline in P300 amplitudes and increase in latency are seen after 24 hours of sleep deprivation and improvements in the P300 are seen after a recovery period. Limited research has been conducted on the effects on P300 amplitude and latency during post recovery periods of three or more hours. The present study was designed to determine the effects of P300 three and six hours post recovery using an oddball paradigm (standard = 1000 Hz; target = 2000 Hz). AEPs were recorded for five conditions: baseline, sleep deprived, 110 minute recovery, three hours post recovery and six hours post recovery. Measures of P300 amplitude and latency were taken from Fz, Cz and Pz electrode sites. Peak to base amplitude and peak to peak amplitude of the P300 were also measured. Fourteen college and university students ages 18-25 were included in this study. Results indicated a significant decrease in P300 amplitude from the six hour post recovery condition compared to the baseline (p \u3c .05) as well as the six hour post recovery condition and sleep deprived condition (p \u3c .05). There were no significant changes in P300 latency across conditions. The results suggest that three to six hours after a brief recovery period of 110 minutes, cognitive decline is exacerbated
Arms Industry
A summary assessment of the dimensions and concentrations of military equipment manufacture primarily in the United States and western Europe and the extent of availability of this equipment to buyers throughout the world. Treaty-based limitations are also listed
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