55,121 research outputs found

    Thermostating by Deterministic Scattering: Heat and Shear Flow

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    We apply a recently proposed novel thermostating mechanism to an interacting many-particle system where the bulk particles are moving according to Hamiltonian dynamics. At the boundaries the system is thermalized by deterministic and time-reversible scattering. We show how this scattering mechanism can be related to stochastic boundary conditions. We subsequently simulate nonequilibrium steady states associated to thermal conduction and shear flow for a hard disk fluid. The bulk behavior of the model is studied by comparing the transport coefficients obtained from computer simulations to theoretical results. Furthermore, thermodynamic entropy production and exponential phase-space contraction rates in the stationary nonequilibrium states are calculated showing that in general these quantities do not agree.Comment: 16 pages (revtex) with 9 figures (postscript

    Manned simulations of the SRMS in SIMFAC

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    SIMFAC is a general purpose real-time simulation facility currently configured with an Orbiter-like Crew Compartment and a Displays and Controls (D and C) Subsystem to support the engineering developments of the Space Shuttle Remote Manipulator (SRMS). The simulation consists of a software model of the anthropomorphic SRMS manipulator arm including the characteristics of its control system and joint drive modules. The following are discussed: (1) simulation and scene generation subsystems; (2) the SRMS task in SIMFAC; (3) operator tactics and options; (4) workload; (5) operator errors and sources; (6) areas for further work; and (7) general observations

    Suggestions for Improved Benchmark Scenarios for Higgs-Boson Searches at LEP2

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    We suggest new benchmark scenarios for the Higgs-boson search at LEP2. Keeping m_t and M_SUSY fixed, we improve on the definition of the maximal mixing benchmark scenario defining precisely the values of all MSSM parameters such that the new m_h^max benchmark scenario yields the parameters which maximize the value of m_h for a given tan(beta). The corresponding scenario with vanishing mixing in the scalar top sector is also considered. We propose a further benchmark scenario with a relatively large value of |mu|, a moderate value of M_SUSY, and moderate mixing parameters in the scalar top sector. While the latter scenario yields m_h values that in principle allow to access the complete M_A-tan(beta)-plane at LEP2, on the other hand it contains parameter regions where the Higgs-boson detection can be difficult, because of a suppression of the branching ratio of its decay into bottom quarks.Comment: 9 pages, no figures, Contribution to the Workshop on ``New Theoretical Developments for Higgs Physics at LEP2'', CERN, October 199

    A Forgotten Issue: Distributional Effects of Day Care Subsidies in Germany

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    In westlichen Industrienationen besteht heute im allgemeinen ein Konsens darüber, dass die Betreuung in Kindertageseinrichtungen öffentlich subventioniert werden sollte. Weniger Klarheit besteht jedoch über die verteilungspolitischen Effekte der öffentlichen Förderung von Kinderbetreuung. Eine solche Unkenntnis über die Verteilungseffekte der öffentlichen Förderung von Kinderbetreuung kann jedoch dazu führen, dass Einkommensgruppen öffentliche Mittel in Anspruch nehmen, die dieser Gelder nicht bedürfen. Wie in einigen anderen europäischen Staaten werden auch in Deutschland bestimmte Anbieter von Kindertageseinrichtungen öffentlich gefördert bzw. die Kommunen betreiben selbst Kindertageseinrichtungen. Damit kommen den Eltern, deren Kinder Kindertageseinrichtungen besuchen, indirekt öffentliche Gelder zu, gleichwohl sie über Elternbeiträge einen geringen Teil der Kosten selbst abdecken. In dieser Studie untersuchen wir die distributiven Effekte der Förderung von Kindertageseinrichtungen in Deutschland, indem wir Mikrodaten auf Haushaltsebene mit Informationen über die öffentlichen Ausgaben im Bereich von Kindertageseinrichtungen kombinieren. Ein wichtiges Ergebnis der Analyse ist, dass über die gegenwärtige "Anbieter-Förderung" nur sehr geringe Umverteilungswirkungen erzielt werden. Vorrangig kommen die Subventionen im Bereich der Kinderbetreuung mittleren Einkommensgruppen zugute, was dem politischen und gesellschaftlichen Ziel, im Kindertagesstättenbereich insbesondere Kinder aus unteren Einkommensgruppen zu fördern, widerspricht. In general child care subsidies are widely accepted as a means to create equal chances for mothers in the labour market as well as for children. Although there is a general consensus that the use of child care should be publicly supported, there is no consensus on how this should be done. Moreover, there is little knowledge on the distributional effects of child care subsidies. In order to assess whether public expenditures are targeted efficiently, it is, however, vital to know which social groups profit most from the public expenditures on children's day care and if tax-payers money is spent effectively. In Germany, as in other European countries, child care subsidies are mainly provided 'in-kind'. Local communities and NPOs provide child care slots for children, which are - except for a small fee - free of charge. In this study we estimate the distributional effects of state funded child day care in Germany using microdata of households and data on the expenditure of public funded child care. Major results are that child care subsidies only carry modest redistributional effects. In the first place, it is the middle income range that profits from the public provision of children's day care. This contradicts common public policy recommendations, which state that low income families should be the first target of child care subsidies.Child day care, child care subsidies, distributional effects, social policy

    The AdHOC study of older adults’ adherence to medication in 11 countries

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    BACKGROUND: Compared with the resources expended developing, evaluating and making clinical decisions about prescribing medication, we know little about what determines whether people take it. Older adults are prescribed more medication than any other group. Poor adherence is a common reason for nonresponse to medication. OBJECTIVES: To investigate cross-nationally the impact of demographic, psychiatric (including cognitive), physical health, behavioural and medication factors on adherence to medication in older adults. METHODS: Researchers interviewed 3881 people over 65 who receive home care services using a structured interview at participants’ places of residence in eleven countries. The main outcome measure was the percentage participants not adherent to medication. RESULTS: 12.5% (n= 456) of people reported they were not fully adherent to medication. Non-adherence was predicted by problem drinking (OR=3.6), not having a doctor review medication (OR=3.3), dementia (OR=1.4 for every one point increase in impairment), good physical health (OR=1.2), resisting care (OR=2.1) being married (OR=2.3) and living in the Czech Republic (OR=4.7) or Germany (OR=1.4). CONCLUSION: People, who screen positive for problem drinking and with dementia, often undiagnosed are less likely to adhere to medication. Therefore doctors should consider dementia and problem drinking when prescribing for older adults. Interventions to improve adherence in older adults might be more effective if 4 targeted at these groups. It is possible that medication review enhances adherence, by improving the patient-doctor relationship, or by emphasising the relevance of medications

    An evaluation of Skylab (EREP) remote sensing techniques applied to investigations of crustal structure

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    The author has identified the following significant results. Film positives (70mm) from all six S190A multispectral photographic camera stations for any one scene can be registered and analyzed in a color additive viewer. Using a multispectral viewer, S190A and B films can be projected directly onto published geologic and topographic maps at scales as large as 1:62,500 and 1:24,000 without significant loss of detail. S190A films and prints permit the detection of faults, fractures, and other linear features not visible in any other space imagery. S192 MSS imagery can be useful for rock-type discrimination studies and delineation of linear patterns and arcuate anomalies. Anomalous color reflectances and arcuate color patterns revealed mineralized zones, copper deposits, vegetation, and volcanic rocks in various locations such as Panamint Range (CA), Greenwater (Death Valley), Lava Mountains (CA), northwestern Arizona, and Coso Hot Springs (CA)

    The German Socio-Economic Panel as Reference Data Set

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    This paper discusses how household panels in general?and the German Socio- Economic Panel (SOEP) in particular?can serve as reference data for researchers collecting datasets that do not represent the full universe of the population of interest (e.g., through clinical trials, intervention studies, laboratory and behavioural experiments, and cohort studies). We first discuss potential benefits of using questions similar to those in the SOEP for studies where researchers are interested in using the SOEP as reference data. We present a comprehensive list of SOEP core questions that we recommend researchers to consider when collecting their own data. We focus on seven topics: (1) demographic and parental characteristics; (2) labour market; (3) health; (4) personality, preferences, and subjective orientations; (5) subjective wellbeing; (6) political involvement and participation, and finally, a set of core questions for young children before they enter school. Of course the selection of a minimum set of questions depends on the research question. In this paper, we offer general advice for the selection of variables to researchers interested in comparing their own data with the SOEP.clinical trials, intervention studies, behavioural experiments, cohort studies, household panels, SOEP, reference data

    The German Socio-Economic Panel as a Reference Data Set

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    This paper discusses how household panels in general - and the German Socio-Economic Panel (SOEP) in particular - can serve as reference data for researchers collecting datasets that do not represent the full universe of the population of interest (e.g., through clinical trials, intervention studies, laboratory and behavioural experiments, and cohort studies). We first discuss potential benefits of using questions similar to those in the SOEP for studies where researchers are interested in using the SOEP as reference data. We present a comprehensive list of SOEP core questions that we recommend researchers to consider when collecting their own data. We focus on seven topics: (1) demographic and parental characteristics; (2) labour market; (3) health; (4) personality, preferences, and subjective orientations; (5) subjective wellbeing; (6) political involvement and participation, and finally, a set of core questions for young children before they enter school. Of course the selection of a minimum set of questions depends on the research question. In this paper, we offer general advice for the selection of variables to researchers interested in comparing their own data with the SOEP.clinical trials, intervention studies, behavioural experiments, cohort studies, household panels, SOEP, reference data
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