6,640 research outputs found

    Review Of The Political Economy Of Tax Reform By T. Ito and A. O. Krueger

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    Review Of Asia Next Giant: South Korea And Late Industrialization By A. H. Amsden

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    Review Of Sources Of Economic-Growth In Korea: 1963-1982 By K.-S. Kim and J.-K. Park

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    Evidence from Strandings for Geomagnetic Sensitivity in Cetaceans

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    We tested the hypothesis that cetaceans use weak anomalies in the geomagnetic field as cues for orientation, navigation and/or piloting. Using the positions of 212 stranding events of live animals in the Smith sonian compilation which fall within the boundaries of the USGS East-Coast Aeromagnetic Survey, we found that there are highly significant tendencies for cetaceans to beach themselves near coastal locations with local magnetic minima. Monte-Carlo simulations confirm the significance of these effects. These results suggest that cetaceans have a magnetic sensory systemcomparable to that in other migratory and homing animals, and predict that the magnetic topography and in particular the marine magnetic lineations may play an important role in guiding long-distance migration. The ‘map’ sense of migratoryanimals may therefore be largely based on a simple strategy of following paths of local magnetic minima and avoiding magnetic gradients

    Industrial Policy In An Export-Propelled Economy: Lessons From South Korea\u27s Experience

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    Korea provides an illuminating case of state intervention to promote economic development. Like many other third world governments, Korea\u27s government has selectively intervened to affect the allocation of resources among industrial activities. It has used taxes and subsidies, credit rationing, various kinds of licensing, and the creation of public enterprises, for example. But these policies have been applied in the context of a radically different development strategy, one of export-led industrialization. Moreover, Korea\u27s economy has experienced exceptionally rapid development with relatively equitable distribution of the gains. This paper argues that the government\u27s selective industrial policies have contributed importantly to Korea\u27s rapid achievement of international competitiveness in a number of industries. Though accepted by many knowledgeable observers, the conclusion is controversial—inherently so owing to insufficient historical information and lack of agreement about the required counterfactual

    Wavefront sensing of atmospheric phase distortions at the Palomar 200-in. telescope and implications for adaptive optics

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    Major efforts in astronomical instrumentation are now being made to apply the techniques of adaptive optics to the correction of phase distortions induced by the turbulent atmosphere and by quasi-static aberrations in telescopes themselves. Despite decades of study, the problem of atmospheric turbulence is still only partially understood. We have obtained video-rate (30 Hz) imaging of stellar clusters and of single-star phase distortions over the pupil of the 200" Hale telescope on Palomar Mountain. These data show complex temporal and spatial behavior, with multiple components arising at a number of scale heights in the atmosphere; we hope to quantify this behavior to ensure the feasibility of adaptive optics at the Observatory. We have implemented different wavefront sensing techniques to measure aperture phase in wavefronts from single stars, including the classical Foucault test, which measures the local gradient of phase, and the recently-devised curvature sensing technique, which measures the second derivative of pupil phase and has formed the real-time wavefront sensor for some very productive astronomical adaptive optics. Our data, though not fast enough to capture all details of atmospheric phase fluctuations, provide important information regarding the capabilities that must be met by the adaptive optics system now being built for the 200" telescope by a team at the Jet Propulsion Lab. We describe our data acquisition techniques, initial results from efforts to characterize the properties of the turbulent atmosphere at Palomar Mountain, and future plans to extract additional quantitative parameters of use for adaptive optics performance predictions

    Monodromy in the CMB: Gravity Waves and String Inflation

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    We present a simple mechanism for obtaining large-field inflation, and hence a gravitational wave signature, from string theory compactified on twisted tori. For Nil manifolds, we obtain a leading inflationary potential proportional to phi^(2/3) in terms of the canonically normalized field phi, yielding predictions for the tilt of the power spectrum and the tensor-to-scalar ratio, ns0.98n_s\approx 0.98 and r0.04r\approx 0.04 with 60 e-foldings of inflation; we note also the possibility of a variant with a candidate inflaton potential proportional to phi^(2/5). The basic mechanism involved in extending the field range -- monodromy in D-branes as they move in circles on the manifold -- arises in a more general class of compactifications, though our methods for controlling the corrections to the slow-roll parameters require additional symmetries.Comment: 43 pages, latex. 4 figure

    Double-branched vortex generator

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    In order to assess the suitability of using a double branched vortex generator in parametric studies involving vortex interactions, an experimental study of the main vortex and secondary flows produced by a double branched vortex generator was conducted in a 20-by-40 cm indraft wind tunnel. Measurements of the cross flow velocities were made with a five hole pressure probe from which vorticity contours and vortex parameters were derived. The results showed that the optimum configuration consisted of chord extensions with the absence of a centerbody
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