137,400 research outputs found

    Impact of World Bank lending in an adjustment-led growth model

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    Within a financial- and growth-programming framework, this paper develops a policy-driven growth model and addresses the effects of World Bank lending on economic growth in a sample of 30 countries, after having controlled for the effects of key macroeconomic variables. Both static and dynamic panel estimates suggest a positive significant effect of the rate of growth in World Bank lending on economic growth, conditional on other variables, namely changes in exchange rate, domestic credit growth, and inflation. Empirical evidence also reveals the positive effect of a macroeconomic policy index in this sample of developing countries

    Cached Sufficient Statistics for Efficient Machine Learning with Large Datasets

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    This paper introduces new algorithms and data structures for quick counting for machine learning datasets. We focus on the counting task of constructing contingency tables, but our approach is also applicable to counting the number of records in a dataset that match conjunctive queries. Subject to certain assumptions, the costs of these operations can be shown to be independent of the number of records in the dataset and loglinear in the number of non-zero entries in the contingency table. We provide a very sparse data structure, the ADtree, to minimize memory use. We provide analytical worst-case bounds for this structure for several models of data distribution. We empirically demonstrate that tractably-sized data structures can be produced for large real-world datasets by (a) using a sparse tree structure that never allocates memory for counts of zero, (b) never allocating memory for counts that can be deduced from other counts, and (c) not bothering to expand the tree fully near its leaves. We show how the ADtree can be used to accelerate Bayes net structure finding algorithms, rule learning algorithms, and feature selection algorithms, and we provide a number of empirical results comparing ADtree methods against traditional direct counting approaches. We also discuss the possible uses of ADtrees in other machine learning methods, and discuss the merits of ADtrees in comparison with alternative representations such as kd-trees, R-trees and Frequent Sets.Comment: See http://www.jair.org/ for any accompanying file

    Japan and the Global Environment

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    Large space antenna technology applied to radar-imaging, rain-rate measurements, and ocean wind sensing

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    During the last decade, the utility of spaceborne microwave remote sensing systems for ocean windspeed measurement, ocean wave imaging and sea ice studies was demonstrated. Development of large space antennas offers some interesting possibilities for rain rate measurements, ocean and ice studies, and radar imaging. The joint use of active and passive sensors using the 15 m antenna for ocean, ice, and soil moisture studies; rain rate measurements; and radar imaging is considered. Verification of the frequency agile rain radar concept with Shuttle offers the possibility of much needed rain rate statistics over the ocean

    Remote sensor imagery in urban research - Some potentialities and problem

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    Imaging techniques of urban data collection for development and plannin

    A Search for Correlations between Gamma-Ray Burst Variability and Afterglow Onset

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    We compared the time (or time limit) of onset for optical afterglow emission to the gamma-ray variability V in 76 GRBs with redshifts. In the subset (25 cases) with the rise evident in the data, we fit the shape of the onset peak as well and compared the rising and decaying indices to V. We did not find any evidence for any patterns between these properties and there is no statistical support for any correlations. This indicates a lack of connection between irregularities of the prompt gamma-ray emission and the establishment of the afterglow phase. In the ordinary prompt internal shocks interpretation, this would indicate a lack of relationship between V and the bulk Lorentz factor of the event.Comment: 14 pages including 8 figures, MNRAS accepte

    Digging for biosynthetic dark matter.

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    An analysis of bacterial communities in soil samples from around the world reveals unexplored diversity in biosynthetic enzymes

    D-particle bound states and generalized instantons

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    We compute the principal contribution to the index in the supersymmetric quantum mechanical systems which are obtained by reduction to 0+1 dimensions of N=1\mathcal{N}=1, D=4,6,10D=4,6,10 super-Yang-Mills theories with gauge group SU(N). The results are: 1N2{1\over{N^{2}}} for D=4,6D=4,6, dN1d2\sum_{d | N} {1\over{d^{2}}} for D=10. We also discuss the D=3 case.Comment: harvmac, 24 pages; v2. references added, typos corrected; v3. one more reference adde

    The impacts of tourism on two communities adjacent to the Kruger National Park, South Africa

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    This paper explores the socioeconomic impacts of tourism associated with the Kruger National Park, South Africa's flagship national park, on the neighbouring villages of Cork and Belfast. Case study research, where the study area was characterised as a social-ecological system, was used to investigate the impacts of Park tourism on these communities. The findings offer a micro-scale, local community perspective of these impacts and indicate that the enclave nature of Park tourism keeps local communities separate from the Park and makes it hard for them to benefit from it. The paper concludes with reflections on this perceived separation, and suggests the need to make the Park boundaries more 'permeable' so as to improve relationships with adjacent communities, while also pragmatically managing community expectation
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