4,286 research outputs found
First-principles investigation of 180-degree domain walls in BaTiO_3
We present a first-principles study of 180-degree ferroelectric domain walls
in tetragonal barium titanate. The theory is based on an effective Hamiltonian
that has previously been determined from first-principles
ultrasoft-pseudopotential calculations. Statistical properties are investigated
using Monte Carlo simulations. We compute the domain-wall energy, free energy,
and thickness, analyze the behavior of the ferroelectric order parameter in the
interior of the domain wall, and study its spatial fluctuations. An abrupt
reversal of the polarization is found, unlike the gradual rotation typical of
the ferromagnetic case.Comment: Revtex (preprint style, 13 pages) + 3 postscript figures. A version
in two-column article style with embedded figures is available at
http://electron.rutgers.edu/~dhv/preprints/index.html#pad_wal
The Timing of Daily Demand for Goods and Services - Multivariate Probit Estimates and Microsimulation Results for an Aged Population with German Time Use Diary Data
The Timing of Daily Demand for Goods and Services – Multivariate Probit Estimates and Microsimulation Results for an Aged Population with German Time Use Diary Data
Though consumption research provides a broad spectrum of theoretical and empirical founded results, studies based on a daily focus are missing. Knowledge about the individual timing of daily demand for goods and services, opens – beyond a genuine contribution to consumption research – interesting societal and macro economic as well as individual personal and firm perspectives: it is important for an efficient timely coordination of supply and demand in the timing perspective as well as for a targeted economic, social and societal policy for a better support of the every day coordination of life. Last not least, the individual daily public and private living situations will be visible, which are of particular importance for the social togetherness in family and society. Our study contributes to the timing of daily consumption for goods and services with an empirical founded microanalysis on the basis of more than 37.000 individual time use diaries of the nationwide Time Budget Survey of the German Federal Statistical Office 2001/02. We describe the individual timing of daily demand for goods and services for important socio-demographic groups like for women and men, the economic situation with income poverty and daily working hour arrangements. The multivariate microeconometric explanation of the daily demand for goods and services is based on a latent utility maximizing approach over a day. We estimate an eight equation Multivariate/Simultaneous Probit Model, which allows the decision for multiple consumption activities in more than one time period a day. The estimates quantify effects on the timing of daily demand by individual socio-economic variables, which encompasses, personal, household, regional characteristics as well as daily working hour arrangements within a flexible labour market.
The question about individual effects of an aged society on the timing of daily demand for goods and services is analyzed with our microsimulation model ServSim and a population forecast for 2020 by the German Federal Statistical Office. Main result: There are significant differences in explaining the timing of daily demand for goods compared to services on the one hand and in particular for different daily time periods.
The conclusion: without the timing aspects an important and significant dimension for understanding individual consumption behaviour and their impacts on other individual living conditions would be missing
Duality and Multicritical Point of Two-Dimensional Spin Glasses
Determination of the precise location of the multicritical point and phase
boundary is a target of active current research in the theory of spin glasses.
In this short note we develop a duality argument to predict the location of the
multicritical point and the shape of the phase boundary in models of spin
glasses on the square lattice.Comment: 4 pages, 1 figure; Reference updated, definition of \tilde{V} added;
to be published in J. Phys. Soc. Jp
Epidemiology of methicillin-resistant Staphylococcus aureus colonization in a surgical intensive care unit
Timing, Fragmentation of Work and Income Inequality - An Earnings Treatment Effects Approach
Traditional welfare analyses based on money income needs to be broadened by its time dimension. In the course of time the traditional full-time work is diminishing and new labour arrangements are discussed (keyword: flexible labour markets). Our study is contributing to economic well-being by adding insights into particular work effort characteristics - the daily timing of work and its fragmentation - and its resulting income distribution.
With our focus on ‘who is working when within a day with which earnings consequences’ we go beyond traditional labour market analyses with its working time division into aggregated full and part time work, working hours spread across a week and weekend, life time working etc.
Whereas the first part of our study is describing the distribution of timing and fragmentation of daily work time
and its resulting income based on more than 35.000 diaries of the recent German Time Budget Survey 2001/2002, the second part of our study quantifies determinants of arrangement specific earnings functions detecting significant explanatory pattern of what is behind. The economic theory behind is a human capital approach in a market and non-market context, extended by non-market time use, the partner’s working condition, social networking as well as household and regional characteristics. The econometrics use a treatment effects type interdependent estimation of endogenous participation (selection) in a daily working hour pattern (self-selection)and pattern specific earnings function explanation.
The overall result: Individual earnings in Germany are dependent on and significant different with regard to the
daily working hour arrangement capturing timing and fragmentation of work time. Market and non-market
factors are important and significant in explaining earnings
The distribution and re-distribution of income of selfemployed as freelancers and entrepreneurs in Europe
The economic transformations of modern industrial societies have changed the labor markets in terms of
industrial relations and occupational structure. The transformation of the traditional welfare state, the
deregulation of the labor markets, the technological change and the reorganization of industrial structures
influenced strongly the attitude of individuals towards their preferred labor contract. The structural change of the
occupational structure was one of the results of this tendency. In particular the self-employed and freelancers
have been affected and are a driving factor of labor market changings. On the one side the value of autonomy
regarding industrial relations is becoming more important for employees. On the other side employers want to
get rid of social security contributions. As a result the multitudinousness of these professions increased.
The increasing varieties of occupations among the self-employed and freelancers influenced strongly their
income distribution. Recent studies for Germany have shown a great dispersion and a heterogeneous structure of
earnings in particular of freelancers (liberal professions) and self-employed. Though there are a variety of
international income distribution studies, but – as to the best to our knowledge – no study focusing on the selfemployed
and freelancers within the total labor force. In our study we concentrate on the income distribution of
self-employed and freelancers in different European countries. Based on the Luxembourg Income Study (LIS)
we analyze five different European countries and the United States structured by different types of welfare states
according to Esping Anderson. We analyze income distributional aspects, an occupational decomposition à la
Shorrocks, and re-distributional effects of the tax and transfer systems
Proline-rich sequence recognition I: Marking GYF and WW domain assembly sites in early spliceosomal complexes.
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