4,895 research outputs found
Job Creation, Destruction and Transition in Poland, 1988-1998: Panel Evidence
Longitudinal data from interviews with Poles of working age conducted in 1988, 1993 and 1998 present a detailed view of the transition from a state dominated to a market economy. Job loss in state firms and job creation in new private firms are the dominant employment change, other than retirements from the labor force. In the Polish case, a significant proportion of this movement over the 1988 to 1998 period involves a period of unemployment or exit from the labor force before obtaining a private sector job. A second feature of the Polish transition is considerable job competition between workers leaving the state sector and those who were out of the labor force at the beginning of the transition. The likelihood of moving to the private sector was higher for the better educated and for residents of regions with a robust de novo economy, suggesting that the supply of jobs in the private sector combined with higher levels of human capital lead to faster and smoother transitions. Lastly, wage differences between the state sector and the de novo sector appear to have little association with mobility, suggesting that movement is not strongly related to the opportunity to find a higher paying job.http://deepblue.lib.umich.edu/bitstream/2027.42/39887/3/wp502.pd
Job Creation, Destruction and Transition in Poland, 1988-1998: Panel Evidence
Longitudinal data from interviews with Poles of working age conducted in 1988, 1993 and 1998 present a detailed view of the transition from a state dominated to a market economy. Job loss in state firms and job creation in new private firms are the dominant employment change, other than retirements from the labor force. In the Polish case, a significant proportion of this movement over the 1988 to 1998 period involves a period of unemployment or exit from the labor force before obtaining a private sector job. A second feature of the Polish transition is considerable job competition between workers leaving the state sector and those who were out of the labor force at the beginning of the transition. The likelihood of moving to the private sector was higher for the better educated and for residents of regions with a robust de novo economy, suggesting that the supply of jobs in the private sector combined with higher levels of human capital lead to faster and smoother transitions. Lastly, wage differences between the state sector and the de novo sector appear to have little association with mobility, suggesting that movement is not strongly related to the opportunity to find a higher paying job.Transition Economics, Labor Mobility, Poland
Predicting Multi-class Customer Profiles Based on Transactions: a Case Study in Food Sales
Predicting the class of a customer profile is a key task in marketing, which enables businesses to approach the right customer with the right product at the right time through the right channel to satisfy the customer's evolving needs. However, due to costs, privacy and/or data protection, only the business' owned transactional data is typically available for constructing customer profiles. Predicting the class of customer profiles based on such data is challenging, as the data tends to be very large, heavily sparse and highly skewed. We present a new approach that is designed to efficiently and accurately handle the multi-class classification of customer profiles built using sparse and skewed transactional data. Our approach first bins the customer profiles on the basis of the number of items transacted. The discovered bins are then partitioned and prototypes within each of the discovered bins selected to build the multi-class classifier models. The results obtained from using four multi-class classifiers on real-world transactional data from the food sales domain consistently show the critical numbers of items at which the predictive performance of customer profiles can be substantially improved
Reducing Spatial Data Complexity for Classification Models
Intelligent data analytics gradually becomes a day-to-day reality of today's businesses. However, despite rapidly
increasing storage and computational power current state-of-the-art predictive models still can not handle massive and noisy
corporate data warehouses. What is more adaptive and real-time operational environment requires multiple models to be
frequently retrained which fiirther hinders their use. Various data reduction techniques ranging from data sampling up to
density retention models attempt to address this challenge by capturing a summarised data structure, yet they either do
not account for labelled data or degrade the classification performance of the model trained on the condensed dataset. Our
response is a proposition of a new general framework for reducing the complexity of labelled data by means of controlled
spatial redistribution of class densities in the input space. On the example of Parzen Labelled Data Compressor (PLDC) we
demonstrate a simulatory data condensation process directly inspired by the electrostatic field interaction where the data are
moved and merged following the attracting and repelling interactions with the other labelled data. The process is controlled
by the class density function built on the original data that acts as a class-sensitive potential field ensuring preservation of
the original class density distributions, yet allowing data to rearrange and merge joining together their soft class partitions.
As a result we achieved a model that reduces the labelled datasets much further than any competitive approaches yet with
the maximum retention of the original class densities and hence the classification performance. PLDC leaves the reduced
dataset with the soft accumulative class weights allowing for efficient online updates and as shown in a series of experiments
if coupled with Parzen Density Classifier (PDC) significantly outperforms competitive data condensation methods in terms of
classification performance at the comparable compression levels
Soliton complexity in the damped-driven nonlinear Schr\"odinger equation: stationary, periodic, quasiperiodic complexes
Stationary and oscillatory bound states, or complexes, of the damped-driven
solitons are numerically path-followed in the parameter space. We compile a
chart of the two-soliton attractors, complementing the one-soliton attractor
chart.Comment: 12 pages, 7 figure
One-dimensional quasi-relativistic particle in the box
Two-term Weyl-type asymptotic law for the eigenvalues of one-dimensional
quasi-relativistic Hamiltonian (-h^2 c^2 d^2/dx^2 + m^2 c^4)^(1/2) + V_well(x)
(the Klein-Gordon square-root operator with electrostatic potential) with the
infinite square well potential V_well(x) is given: the n-th eigenvalue is equal
to (n pi/2 - pi/8) h c/a + O(1/n), where 2a is the width of the potential well.
Simplicity of eigenvalues is proved. Some L^2 and L^infinity properties of
eigenfunctions are also studied. Eigenvalues represent energies of a `massive
particle in the box' quasi-relativistic model.Comment: 40 pages, 4 figures; minor correction
Dust effects on the derived Sersic indexes of disks and bulges in spiral galaxies
We present a theoretical study that quantifies the effect of dust on the
derived Sersic indexes of disks and bulges. The changes in the derived
parameters from their intrinsic values (as seen in the absence of dust) were
obtained by fitting Sersic distributions on simulated images of disks and
bulges produced using radiative transfer calculations and the model of Popescu
et al. 2011. We found that dust has the effect of lowering the measured Sersic
index in most cases, with stronger effects for disks and bulges seen through
more optically thick lines of sight.Comment: 3 pages, 2 figures, to appear in the Proceedings of the IAU Symposium
No.284, "The Spectral Energy Distribution of Galaxies", 5-9 sept. 2011,
editors Richard J. Tuffs and Cristina C. Popesc
The Health System and the Russian Orthodox Church: Prospects for Development
The article examines the participation and assistance of the Orthodox Church in solving problems that allowed to give a scientific justification for the cooperation of health care and Orthodox religious institutions, to determine their role in the historical context and structure of modern healthcare in Russia. The article presents an algorithm for organizing sisters of mercy, their system of upbringing. Particular attention is given to the possibility of teaching the course "Foundations of Orthodox Culture" in secular educational institutions.
Research materials can serve as a basis for the formation of morally sound positions of medical workers and the population on the main problems of medical activity.
Based on the study, the authors published a series of articles in which the experience of the work of the Orthodox Church in the charitable sphere has been summarized. This experience can be used to create new charitable institutions, including those who provided medical assistance.
In preparing the article, the authors used concrete historical, civilizational, formational and social methods of research that allowed us to uncover facts, phenomena and processes in the interconnection and unity of the past, present and future
Upper limits on the luminosity of the progenitor of type Ia supernova SN2014J
We analysed archival data of Chandra pre-explosion observations of the
position of SN2014J in M82. No X-ray source at this position was detected in
the data, and we calculated upper limits on the luminosities of the progenitor.
These upper limits allow us to firmly rule out an unobscured supersoft X-ray
source progenitor with a photospheric radius comparable to the radius of white
dwarf near the Chandrasekhar mass (~1.38 M_sun) and mass accretion rate in the
interval where stable nuclear burning can occur. However, due to a relatively
large hydrogen column density implied by optical observations of the supernova,
we cannot exclude a supersoft source with lower temperatures, kT < 80 eV. We
find that the supernova is located in the centre of a large structure of soft
diffuse emission, about 200 pc across. The mass, ~3x10^4 M_sun and short
cooling time of the gas, tau_cool ~ 8 Myrs, suggest that it is a
supernova-inflated super-bubble, associated with the region of recent star
formation. If SN2014J is indeed located inside the bubble, it likely belongs to
the prompt population of type Ia supernovae, with a delay time as short as ~ 50
Myrs. Finally, we analysed the one existing post-supernova Chandra observation
and placed upper limit of ~ (1-2) 10^37 erg/s on the X-ray luminosity of the
supernova itself.Comment: 8 pages, 6 figure
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