924 research outputs found
The Employment, Earnings, and Income of Less-Skilled Workers over the Business Cycle
In this paper, I examine the effect of business cycles on the employment, earnings, and income of persons in different demographic groups. I classify individuals by sex, education, and race. The analysis uses data from the Current Population Surveyâs Outgoing Rotation Group data, covering the period 1979â1992, and March Annual Demographic File data, covering the period 1975â1997. Many different individual and family outcome measures are considered, including employment to population ratios, weekly earnings, hourly earnings, annual hours, annual earnings, family earnings, family transfer income, and total family income. The regression model is specified such that the key parameters measure how the labor market outcomes of less-skilled workers vary with the business cycle relative to the variability for high-skill groups. The analysis uses variation across MSAs in the timing and severity of shocks. The results consistently show that individuals with lower educational levels, nonwhites, and low-skill women experience greater cyclical fluctuation than high-skill men. These results are the most striking when examining comprehensive measures of labor force activity such as the likelihood of full-time, full-year work. Government transfers and the earnings of other family members decrease the differences between groups, resulting in more skill-group-neutral effects of business cycles on family income than on individual earnings. The paper examines the stability of these results by comparing evidence across the 1982 and 1992 recessions. The evidence suggests that the 1992 recession led to more uniform effects across skill groups than did earlier cycles.
Rising Level of Public Exposure to Mobile Phones: Accumulation through Additivity and Reflectivity
A dramatic development occurring in our daily life is the increasing use of
mobile equipment including mobile phones and wireless access to the Internet.
They enable us to access several types of information more easily than in the
past. Simultaneously, the density of mobile users is rapidly increasing. When
hundreds of mobile phones emit radiation, their total power is found to be
comparable to that of a microwave oven or a satellite broadcasting station.
Thus, the question arises: what is the public exposure level in an area with
many sources of electromagnetic wave emission? We show that this level can
reach the reference level for general public exposure (ICNIRP Guideline) in
daily life. This is caused by the fundamental properties of electromagnetic
field, namely, reflection and additivity. The level of exposure is found to be
much higher than that estimated by the conventional framework of analysis that
assumes that the level rapidly decreases with the inverse square distance
between the source and the affected person. A simple formula for the exposure
level is derived by applying energetics to the electromagnetic field. The
formula reveals a potential risk of intensive exposure.Comment: 5 pages, 1 fugure; to appear in J. Phys. Soc. Jpn. Vol.71 No.2 in Feb
200
Palaeogene glendonites from Denmark
Pristinely preserved mineral pseudomorphs called glendonites, up to 1.6 m long, from the Palaeogene strata of Denmark allow detailed crystallographic characterisation and add to the understanding of the transformation of the precursor mineral, ikaite (CaCO3 center dot 6H(2)O), to calcite, which constitutes the glendonite. We describe Danish pseudomorphs after ikaite from two localities and formations: the Early Eocene Fur Formation and the Late Oligocene Brejning Formation. This detailed study highlights that key aspects such as morphology and mode of occurrence of these ancient glendonites are identical to those of their parent mineral ikaite, when it grows in marine sediments. Systematic distortion of the angles in glendonite and marine sedimentary ikaite relative to the ideal ikaite symmetry may arise due to the incorporation of organic matter into the crystal structure, and we demonstrate the similarity between modern and ancient ikaite formation zones in the marine sedimentary realm with respect to organic matter
Data Mining Approaches to Diffuse Large BâCell Lymphoma Gene Expression Data Interpretation
This paper presents a comprehensive study of gene expression patterns originating from a diffuse large Bâcell lymphoma (DLBCL) database. It focuses on the implementation of feature selection and classification techniques. Thus, it firstly tackles the identification of relevant genes for the prediction of DLBCL types. It also allows the determination of key biomarkers to differentiate two subtypes of DLBCL samples: Activated BâLike and Germinal Centre BâLike DLBCL. Decision trees provide knowledgeâbased models to predict types and subtypes of DLBCL. This research suggests that the data may be insufficient to accurately predict DLBCL types or even detect functionally relevant genes. However, these methods represent reliable and understandable tools to start thinking about possible interesting nonâlinear interdependencies
The availability of land for perennial energy crops in Great Britain
This paper defines the potentially available land for perennial energy crops across Great Britain as the first component of a broader appraisal undertaken by the âSpatial Modelling of Bioenergy in Great Britain to 2050â project. Combining data on seven primary constraints in a GIS reduced the available area to just over 9 M ha (40% of GB). Adding other restrictions based on land cover naturalness scores to represent landscape considerations resulted in a final area of 8.5 M ha (37% of GB). This distribution was compared with the locations of Miscanthus and SRC willow established under the English Energy Crop Scheme during 2001â2011 and it was found that 83% of the planting fell within the defined available land. Such a correspondence provides confidence that the factors considered in the analysis were broadly consistent with previous planting decisions
-self-adjoint operators with -symmetries: extension theory approach
A well known tool in conventional (von Neumann) quantum mechanics is the
self-adjoint extension technique for symmetric operators. It is used, e.g., for
the construction of Dirac-Hermitian Hamiltonians with point-interaction
potentials. Here we reshape this technique to allow for the construction of
pseudo-Hermitian (-self-adjoint) Hamiltonians with complex
point-interactions. We demonstrate that the resulting Hamiltonians are
bijectively related with so called hypermaximal neutral subspaces of the defect
Krein space of the symmetric operator. This symmetric operator is allowed to
have arbitrary but equal deficiency indices . General properties of the
$\cC$ operators for these Hamiltonians are derived. A detailed study of
$\cC$-operator parametrizations and Krein type resolvent formulas is provided
for $J$-self-adjoint extensions of symmetric operators with deficiency indices
. The technique is exemplified on 1D pseudo-Hermitian Schr\"odinger and
Dirac Hamiltonians with complex point-interaction potentials
Non-extremal Localised Branes and Vacuum Solutions in M-Theory
Non-extremal overlapping p-brane supergravity solutions localised in their
relative transverse coordinates are constructed. The construction uses an
algebraic method of solving the bosonic equations of motion. It is shown that
these non-extremal solutions can be obtained from the extremal solutions by
means of the superposition of two deformation functions defined by vacuum
solutions of M-theory. Vacuum solutions of M-theory including irrational powers
of harmonic functions are discussed.Comment: LaTeX, 16 pages, no figures, typos correcte
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