4,678 research outputs found
High Performance P3M N-body code: CUBEP3M
This paper presents CUBEP3M, a publicly-available high performance
cosmological N-body code and describes many utilities and extensions that have
been added to the standard package. These include a memory-light runtime SO
halo finder, a non-Gaussian initial conditions generator, and a system of
unique particle identification. CUBEP3M is fast, its accuracy is tuneable to
optimize speed or memory, and has been run on more than 27,000 cores, achieving
within a factor of two of ideal weak scaling even at this problem size. The
code can be run in an extra-lean mode where the peak memory imprint for large
runs is as low as 37 bytes per particles, which is almost two times leaner than
other widely used N-body codes. However, load imbalances can increase this
requirement by a factor of two, such that fast configurations with all the
utilities enabled and load imbalances factored in require between 70 and 120
bytes per particles. CUBEP3M is well designed to study large scales
cosmological systems, where imbalances are not too large and adaptive
time-stepping not essential. It has already been used for a broad number of
science applications that require either large samples of non-linear
realizations or very large dark matter N-body simulations, including
cosmological reionization, halo formation, baryonic acoustic oscillations, weak
lensing or non-Gaussian statistics. We discuss the structure, the accuracy,
known systematic effects and the scaling performance of the code and its
utilities, when applicable.Comment: 20 pages, 17 figures, added halo profiles, updated to match MNRAS
accepted versio
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
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
The Distribution and Re-Distribution of Income of Selfemployed as Freelancers and Entrepreneurs in Europe
A field study from the Oderbruch, Germany
The behavior of organophosphates and ethers during riverbank filtration and
groundwater flow was assessed to determine their suitability as organic
tracers. Four sampling campaigns were conducted at the Oderbruch polder,
Germany to establish the presence of chlorinated flame retardants (TCEP, TCPP,
TDCP), non-chlorinated plasticizers (TBEP, TiBP, TnBP), and hydrophilic ethers
(1,4-dioxane, monoglyme, diglyme, triglyme, tetraglyme) in the Oder River,
main drainage ditch, and anoxic aquifer. Selected parameters were measured in
order to determine the hydro-chemical composition of both, river water and
groundwater. The results of the study confirm that organophosphates (OPs) are
more readily attenuated during bank filtration compared to ethers. Both in the
river and the groundwater, TCPP was the most abundant OP with concentrations
in the main drainage ditch ranging between 105 and 958 ng L−1. 1,4-dioxane,
triglyme, and tetraglyme demonstrated persistent behavior during bank
filtration and in the anoxic groundwater. In the drainage ditch concentrations
of 1,4-dioxane, triglyme, and tetraglyme ranged between 1090 and 1467 ng L− 1,
37 and 149 ng L− 1, and 496 and 1403 ng L− 1, respectively. A positive
correlation was found for the inorganic tracer chloride with 1,4-dioxane and
tetraglyme. These results confirm the possible application of these ethers as
environmental organic tracers. Both inorganic and organic compounds showed
temporal variability in the surface- and groundwater. Discharge of the river
water, concentrations of analytes at the time of infiltration and attenuation
were identified as factors influencing the variable amounts of the analytes in
the surface and groundwater. These findings are also of great importance for
the production of drinking water via bank filtration and natural and
artificial groundwater recharge as the physicochemical properties of ethers
create challenges in their removal
Microwave Lens for Polar Molecules
We here report on the implementation of a microwave lens for neutral polar
molecules suitable to focus molecules both in low-field-seeking and in
high-field-seeking states. By using the TE_11m modes of a 12 cm long
cylindrically symmetric microwave resonator, Stark-decelerated ammonia
molecules are transversally confined. We investigate the focusing properties of
this microwave lens as a function of the molecules' velocity, the detuning of
the microwave frequency from the molecular resonance frequency, and the
microwave power. Such a microwave lens can be seen as a first important step
towards further microwave devices, such as decelerators and traps.Comment: 4 pages, 3 figure
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