9,702 research outputs found

    Efficient calculation of the worst-case error and (fast) component-by-component construction of higher order polynomial lattice rules

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    We show how to obtain a fast component-by-component construction algorithm for higher order polynomial lattice rules. Such rules are useful for multivariate quadrature of high-dimensional smooth functions over the unit cube as they achieve the near optimal order of convergence. The main problem addressed in this paper is to find an efficient way of computing the worst-case error. A general algorithm is presented and explicit expressions for base~2 are given. To obtain an efficient component-by-component construction algorithm we exploit the structure of the underlying cyclic group. We compare our new higher order multivariate quadrature rules to existing quadrature rules based on higher order digital nets by computing their worst-case error. These numerical results show that the higher order polynomial lattice rules improve upon the known constructions of quasi-Monte Carlo rules based on higher order digital nets

    The T1 state of p-nitroaniline and related molecules: a CNDO/S study

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    The nature of the lowest energy triplet state (T1) of p-nitroaniline (PNA), N,N-dimethyl-p-nitroaniline (DMPNA) and nitrobenzene (NB) is reexamd. using the semiempirical CNDO/S-CI method with selected parameter options. In the case of the unperturbed mols. the short-axis polarized p* A- singlet excitation. Computations suggest, however, that polar solvents strongly stabilize the PNA and DMPNA p* <- p charge-transfer triplet relative to other excitations, whereas specific solvent hydrogen-bonded interactions stabilize the p* <- n(s) triplet of NB below those of p* <- p character. These assignments allow a rationalization of phosphorescence lifetime data, Tn <- T1 absorption measurements and relative photochem. behavior

    Differential Entropy on Statistical Spaces

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    We show that the previously introduced concept of distance on statistical spaces leads to a straightforward definition of differential entropy on these statistical spaces. These spaces are characterized by the fact that their points can only be localized within a certain volume and exhibit thus a feature of fuzziness. This implies that Riemann integrability of relevant integrals is no longer secured. Some discussion on the specialization of this formalism to quantum states concludes the paper.Comment: 4 pages, to appear in the proceedings of the joint meeting of the 2nd International Conference on Cybernetics and Information Technologies, Systems and Applications (CITSA 2005) and the 11th International Conference on Information Systems Analysis and Synthesis (ISAS 2005), to be held in Orlando, USA, on July 14-17, 200

    Water Allocation Mechanisms: Principles and Examples

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    From the earliest times, water resources have been allocated on the basis of social criteria - maintaining the community by ensuring that water is available for human consumption, for sanitation, and for food production. Societies have invested capital in infrastructure to maintain this allocation. Yet social change, including changes in (and more understanding of) how goods are distributed, has produced new issues in water allocation. Population growth has made water scarcity a major problem in many countries and water pollution, while by no means a recent problem, is more widespread than ever before. Traditionally the state has played a dominant role in managing water resources, but inefficient use of water, poor cost recovery for operating and maintenance expenses, the mounting cost of developing new water sources, and problems with the quality of service in agency-managed systems has led to a search for alternatives that make water allocation and management more efficient. The authors address some of the basic principles of treating water as an economic good and of allocating it among the sectors. After outlining the economic principles behind allocating scarce water resources, they review the actual means of various mechanisms used for allocating water, including marginal cost pricing, social planning, user-based allocation, and water markets. Giving examples from experience in several countries, they weigh the pros and cons of different approaches to water allocation, showing that no single approach is suitable for all situations. Clearly that state must play an important regulatory role, for example, but how effectively it does so depends on the relative political influence of various stakeholders and segments of society. User-based allocation is generally more flexible than state allocation, but collective action is not equally effective everywhere; it is most likely to emerge where there is strong demand for water and a history of cooperation. The outcome of market allocation depends on the economic value of water for various uses, but moving toward tradable property rights in water may ease the process of intersectoral reallocation by compensating the"losers"and creating incentives for efficient water use in all sectors

    Water allocation mechanisms : principles and examples

    Get PDF
    From the earliest times, water resources have been allocated on the basis of social criteria -maintaining the community by ensuring that water is available for human consumption, for sanitation, and for food production. Societies have invested capital in infrastructure to maintain this allocation. Yet social change, including changes in (and more understanding of) how goods are distributed, has produced new issues in water allocation. Population growth has made water scarcity a major problem in many countries and water pollution, while by no means a recent problem, is more widespread than ever before. Traditionally the state has played a dominant role in managing water resources, but inefficient use of water, poor cost recovery for operating and maintenance expenses, the mounting cost of developing new water sources, and problems with the quality of service in agency-managed systems has led to a search for alternatives that make water allocation and management more efficient. The authors address some of the basic principles of treating water as an economic good and of allocating it among the sectors. After outlining the economic principles behind allocating scarce water resources, they review the actual means of various mechanisms used for allocating water, including marginal cost pricing, social planning, user-based allocation, and water markets. Giving examples from experience in several countries, they weigh the pros and cons of different approaches to water allocation, showing that no single approach is suitable for all situations. Clearly that state must play an important regulatory role, for example, but how effectively it does so depends on the relative political influence of various stakeholders and segments of society. User-based allocation is generally more flexible than state allocation, but collective action is not equally effective everywhere; it is most likely to emerge where there is strong demand for water and a history of cooperation. The outcome of market allocation depends on the economic value of water for various uses, but moving toward tradable property rights in water may ease the process of intersectoral reallocation by compensating the"losers"and creating incentives for efficient water use in all sectors.Water Conservation,Decentralization,Water and Industry,Environmental Economics&Policies,Water Resources Law,Water Supply and Sanitation Governance and Institutions,Town Water Supply and Sanitation,Water and Industry,Water Conservation,Environmental Economics&Policies

    An evaluation of the accounting rate of return : evidence for Dutch quoted firms

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    Although the accounting rate of return (ARR) is traditionally regarded as an important profitability measure in ratio analysis, there has been relatively little theoretical and empirical analysis on its statistical properties and its intrinsic ability to explain market returns. This paper provides an empirical examination of the distributional properties and a time-series analysis of the ARR’s of listed Dutch companies for the years from 1978 to 1997. Furthermore we examine how the ARR is related to market return and risk. We investigate the distributional properties of the accounting rate of return. Our study confirms prior international research which concludes that ARR follows a non-normal distribution. Previous US and UK studies suggest that time series earnings or ARR can be characterized by a random walk or a mean-reverting process. The time series results of our sample are characterized by mean reversion. This paper extends the empirical research on ARR by deriving a panel data analysis that yields more reliable estimates. Researchers using US data found that the ARR was deficient as a representation of market returns and was not related to systematic risk. We find the opposite.

    Nursing Home Infection Control Program Characteristics, CMS Citations, and Implementation of Antibiotic Stewardship Policies: A National Study.

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    Recently, the Centers for Medicare & Medicaid Services (CMS) final rule required that nursing homes (NHs) develop an infection control program that includes an antibiotic stewardship component and employs a trained infection preventionist (IP). The objectives of this study were to provide a baseline assessment of (1) NH facility and infection control program characteristics associated with having an infection control deficiency citation and (2) associations between IP training and the presence of antibiotic stewardship policies, controlling for NH characteristics. A cross-sectional survey of 2514 randomly sampled US NHs was conducted to assess IP training, staff turnover, and infection control program characteristics (ie, frequency of infection control committee meetings and the presence of 7 antibiotic stewardship policies). Responses were linked to concurrent Certification and Survey Provider Enhanced Reporting data, which contain information about NH facility characteristics and citations. Descriptive statistics and multivariable regression analyses were conducted to account for NH characteristics. Surveys were received from 990 NHs; 922 had complete data. One-third of NHs in this sample received an infection control deficiency citation. The NHs that received deficiency citations were more likely to have committees that met weekly/monthly versus quarterly ( P \u3c .01). The IPs in 39% of facilities had received specialized training. Less than 3% of trained IPs were certified in infection control. The NHs with trained IPs were more likely to have 5 of the 7 components of antibiotic stewardship in place (all P \u3c .05). The IP training, although infrequent, was associated with the presence of antibiotic stewardship policies. Receiving an infection control citation was associated with more frequent infection control committee meetings. Training and support of IPs is needed to ensure infection control and antibiotic stewardship in NHs. As the CMS rule becomes implemented, more research is warranted. There is a need for increase in trained IPs in US NHs. These data can be used to evaluate the effectiveness of the CMS final rule on infection management processes in US NHs

    The Rise of a Middle Class and the Changing Concept of Equity in Indonesia: An Interpretation

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    Page range: 71-9

    New interpretations of fine-scale spatial genetic structure

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72211/1/j.1365-294X.2008.03728.x.pd

    Overcoming water scarcity and quality constraints:

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    CONTENTS: Brief 1. Overview / Ruth S. Meinzen-Dick and Mark W. Rosegrant Brief 2. Water for Food Production / Mark W. Rosegrant and Ximing Cai Brief 3. Domestic Water Supply, Hygiene, and Sanitation / Hans van Damme Brief 4. Emerging Water Quality Problems in Developing Countries / Wim van der Hoeck - -Brief 5. Water and Rural Livelihoods / Linden Vincent Brief 6. Water and the Environment / Elro Bos and Ger Bergkamp Brief 7. Dams and Water Storage / Jeremy Bird and Pamela Wallace Brief 8. Groundwater: Potential and Constraints / Marcus Moench Brief 9. Water Harvesting and Watershed Management / John Kerr and Ganesh Pangare Brief 10. Water Pricing: Potential and Problems / R. Maria Saleth Brief 11. Markets for Tradable Water Rights / Karin E. Kemper Brief 12. Recognizing Water Rights / Franz and Keebet von Benda-Beckmann Brief 12. Integrated Management of Water in River Basins / Mark Svendsen Brief 13.Water, Conflict, and Cooperation / Aaron T. WolfWater quality management., Water rights., Water-supply,
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