13,567 research outputs found
The effects of recessions across demographic groups
The burdens of a recession are not spread evenly across demographic groups. As the public and media noticed, from the start of the current recession in December 2007 through June 2009 men accounted for more than three-quarters of net job losses. Other differences have garnered less attention but are just as interesting. During the same period, the employment of single people fell at more than twice the rate that it did for married people and the decline for black workers was one and a half times that for white workers. To provide a more complete understanding of the effect of recessions, this paper examines the different effects of this and previous recessions across a range of demographic categories: sex, marital status, race, age, and education level.Recessions ; Demography
A journal ranking for the ambitious economist
The authors devise an "ambition-adjusted" journal ranking based on citations from a short list of top general-interest journals in economics. Underlying this ranking is the notion that an ambitious economist wishes to be acknowledged not only in the highest reaches of the profession, but also outside his or her subfield. In addition to the conceptual advantages that they find in their ambition adjustment, they see two main practical advantages: greater transparency and a consistent treatment of subfields. They compare their 2008 ranking based on citations from 2001 to 2007 with a ranking for 2002 based on citations from 1995 to 2001.Research ; Economics ; Economists
A Machine Learning Approach to Identify the Preferred Representational System of a Person
Whenever people think about something or engage in activities, internal mental processes will be engaged. These processes consist of sensory representations, such as visual, auditory, and kinesthetic, which are constantly being used, and they can have an impact on a person’s performance. Each person has a preferred representational system they use most when speaking, learning, or communicating, and identifying it can explain a large part of their exhibited behaviours and characteristics. This paper proposes a machine learning-based automated approach to identify the preferred representational system of a person that is used unconsciously. A novel methodology has been used to create a specific labelled conversational dataset, four different machine learning models (support vector machine, logistic regression, random forest, and k-nearest neighbour) have been implemented, and the performance of these models has been evaluated and compared. The results show that the support vector machine model has the best performance for identifying a person’s preferred representational system, as it has a better mean accuracy score compared to the other approaches after the performance of 10-fold cross-validation. The automated model proposed here can assist Neuro Linguistic Programming practitioners and psychologists to have a better understanding of their clients’ behavioural patterns and the relevant cognitive processes. It can also be used by people and organisations in order to achieve their goals in personal development and management. The two main knowledge contributions in this paper are the creation of the first labelled dataset for representational systems, which is now publicly available, and the use of machine learning techniques for the first time to identify a person’s preferred representational system in an automated way
Structural characterization of YBa(2)Cu(3)O(7)/Y(2)O(3) composite films
Using 4-circle x-ray diffraction and transmission electron microscopy we have
studied the microstructure and in-plane orientation of the phases present in
thin film composite mixtures of YBa(2)Cu(3)O(7) and Y(2)O(3). We see a high
degree of in-plane orientation and have verified a previous prediction for the
in-plane order of Y(2)BaCuO(5) on (110) MgO. Transmission electron microscopy
shows the composite films to be a mixture of two phases, with YBCO grain sizes
of 1 micron. We have also compared our observations of the in-plane order to
the predictions of a modified near coincidence site lattice model.Comment: To be published in Journal of Materials Research, (4 pages, 4 jpeg
figures
The effects of recessions across demographic groups
The burdens of a recession are not spread evenly across demographic groups. The public and media, for example, noticed that, from the start of the current recession in December 2007 through June 2009, men accounted for more than three quarters of net job losses. Other differences have garnered less attention, but are just as interesting. During the same period, the employment of single people fell at more than twice the rate that it did for married people, while black employment fell at one-and-a-half times the rate that white employment did. To have a more complete understanding about what recessions mean for people, this paper examines the different effects of this and previous recessions on employment experiences across a range of demographic categories: sex, marital status, race, age, and education level.Recessions ; Demography
Variance and Skewness in the FIRST survey
We investigate the large-scale clustering of radio sources in the FIRST
1.4-GHz survey by analysing the distribution function (counts in cells). We
select a reliable sample from the the FIRST catalogue, paying particular
attention to the problem of how to define single radio sources from the
multiple components listed. We also consider the incompleteness of the
catalogue. We estimate the angular two-point correlation function ,
the variance , and skewness of the distribution for the
various sub-samples chosen on different criteria. Both and
show power-law behaviour with an amplitude corresponding a spatial correlation
length of Mpc. We detect significant skewness in the
distribution, the first such detection in radio surveys. This skewness is found
to be related to the variance through , with
, consistent with the non-linear gravitational growth of
perturbations from primordial Gaussian initial conditions. We show that the
amplitude of variance and skewness are consistent with realistic models of
galaxy clustering.Comment: 13 pages, 21 inline figures, to appear in MNRA
Advanced flight deck/crew station simulator functional requirements
This report documents a study of flight deck/crew system research facility requirements for investigating issues involved with developing systems, and procedures for interfacing transport aircraft with air traffic control systems planned for 1985 to 2000. Crew system needs of NASA, the U.S. Air Force, and industry were investigated and reported. A matrix of these is included, as are recommended functional requirements and design criteria for simulation facilities in which to conduct this research. Methods of exploiting the commonality and similarity in facilities are identified, and plans for exploiting this in order to reduce implementation costs and allow efficient transfer of experiments from one facility to another are presented
The Redshift Distribution of FIRST Radio Sources at 1 mJy
We present spectra for a sample of radio sources from the FIRST survey, and
use them to define the form of the redshift distribution of radio sources at
mJy levels.We targeted 365 sources and obtained 46 redshifts (13 per cent of
the sample). We find that our sample is complete in redshift measurement to R
, corresponding to . Early-type galaxies represent the
largest subset (45 per cent) of the sample and have redshifts 0.15\la z \la
0.5 ; late-type galaxies make up 15 per cent of the sample and have redshifts
0.05\la z \la 0.2; starbursting galaxies are a small fraction ( per
cent), and are very nearby (z\la 0.05). Some 9 per cent of the population
have Seyfert1/quasar-type spectra, all at z\ga 0.8, and there are 4 per cent
are Seyfert2 type galaxies at intermediate redshifts (). Using our
measurements and data from the Phoenix survey, we obtain an estimate for
at mJy and compare this with model predictions. At
variance with previous conclusions, we find that the population of starbursting
objects makes up \la 5 per cent of the radio population at S mJy.Comment: 20 pages, sumbitted to MNRA
Business cycle phases in U.S. states
The U.S. aggregate business cycle is often characterized as a series of distinct recession and expansion phases. We apply a regime-switching model to state-level coincident indexes to characterize state business cycles in this way. We find that states differ a great deal in the levels of growth that they experience in the two phases: Recession growth rates are related to industry mix, whereas expansion growth rates are related to education and age composition. Further, states differ significantly in the timing of switches between regimes, indicating large differences in the extent to which state business cycle phases are in concord with those of the aggregate economy.Business cycles ; Regional economics
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