28,675 research outputs found

    Exploiting multi-word units in history-based probabilistic generation

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    We present a simple history-based model for sentence generation from LFG f-structures, which improves on the accuracy of previous models by breaking down PCFG independence assumptions so that more f-structure conditioning context is used in the prediction of grammar rule expansions. In addition, we present work on experiments with named entities and other multi-word units, showing a statistically significant improvement of generation accuracy. Tested on section 23 of the PennWall Street Journal Treebank, the techniques described in this paper improve BLEU scores from 66.52 to 68.82, and coverage from 98.18% to 99.96%

    Building a Generation Knowledge Source using Internet-Accessible Newswire

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    In this paper, we describe a method for automatic creation of a knowledge source for text generation using information extraction over the Internet. We present a prototype system called PROFILE which uses a client-server architecture to extract noun-phrase descriptions of entities such as people, places, and organizations. The system serves two purposes: as an information extraction tool, it allows users to search for textual descriptions of entities; as a utility to generate functional descriptions (FD), it is used in a functional-unification based generation system. We present an evaluation of the approach and its applications to natural language generation and summarization.Comment: 8 pages, uses eps

    A new approach to multi-frequency synthesis in radio interferometry

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    We present a new approach to multi-frequency synthesis in radio astronomy. Using Bayesian inference techniques, the new technique estimates the sky brightness and the spectral index simultaneously. In principle, the bandwidth of a wide-band observation can be fully exploited for sensitivity and resolution, currently only limited by higher order effects like spectral curvature. Employing this new approach, we further present a multi-frequency extension to the imaging algorithm RESOLVE. In simulations, this new algorithm outperforms current multi-frequency imaging techniques like MS-MF-CLEAN.Comment: 13 pages, 5 fugures, submitted to Astronomy and Astrophysic

    The Promises and Possibilities of the Pitch: 1990s Ladies League Soccer Players as Fin-de-Siècle Modern Girls

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    Dr. Edwards\u27 contribution to: Miller, Laura, et al. Modern Girls on the Go: Gender, Mobility, and Labor in Japan. Stanford University Press, 2013

    Global Security, Climate Change, and the Arctic

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    This issue of Swords and Ploughshares examines the complex set of global security challenges that are emerging as a result of warmer temperatures and melting ice in the Arctic region. For policymakers and analysts alike, the contemporary Arctic presents a particularly acute convergence of compelling problems and opportunities related to global security, foreign affairs, climate change, environmentalism, international law, energy economics, and the rights of indigenous populations. The goals of this publication are two-fold: to provide thoughtful analysis of recent developments in the Arctic both from scientific and geopolitical perspectives; and to offer careful and informed assessments of how evolving conditions in the Arctic might impact the broader global security framework and relations between the international actors involved, not to mention the region’s inhabitants and ecosystem. The articles in this issue were contributed by each of four panelists invited by the Program in Arms Control, Disarmament, and International Security (ACDIS), the European Union Center, and the Russian, East European, and Eurasian Center at the University of Illinois to participate in a November 2009 symposium entitled “Global Security, Climate Change, and the Arctic: Implications of an Open Northwest Passage.” The symposium and this publication were supported through grants to the host centers from the European Commission, the US Department of Education (Title VI international education program), and the John D. and Catherine T. MacArthur Foundation.published or submitted for publicationnot peer reviewe

    Treebank-based acquisition of Chinese LFG resources for parsing and generation

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    This thesis describes a treebank-based approach to automatically acquire robust,wide-coverage Lexical-Functional Grammar (LFG) resources for Chinese parsing and generation, which is part of a larger project on the rapid construction of deep, large-scale, constraint-based, multilingual grammatical resources. I present an application-oriented LFG analysis for Chinese core linguistic phenomena and (in cooperation with PARC) develop a gold-standard dependency-bank of Chinese f-structures for evaluation. Based on the Penn Chinese Treebank, I design and implement two architectures for inducing Chinese LFG resources, one annotation-based and the other dependency conversion-based. I then apply the f-structure acquisition algorithm together with external, state-of-the-art parsers to parsing new text into "proto" f-structures. In order to convert "proto" f-structures into "proper" f-structures or deep dependencies, I present a novel Non-Local Dependency (NLD) recovery algorithm using subcategorisation frames and f-structure paths linking antecedents and traces in NLDs extracted from the automatically-built LFG f-structure treebank. Based on the grammars extracted from the f-structure annotated treebank, I develop a PCFG-based chart generator and a new n-gram based pure dependency generator to realise Chinese sentences from LFG f-structures. The work reported in this thesis is the first effort to scale treebank-based, probabilistic Chinese LFG resources from proof-of-concept research to unrestricted, real text. Although this thesis concentrates on Chinese and LFG, many of the methodologies, e.g. the acquisition of predicate-argument structures, NLD resolution and the PCFG- and dependency n-gram-based generation models, are largely language and formalism independent and should generalise to diverse languages as well as to labelled bilexical dependency representations other than LFG

    Large Angular Scale Polarization of the Cosmic Microwave Background and the Feasibility of its Detection

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    In addition to its spectrum and temperature anisotropy, the 2.7K Cosmic Microwave Background is also expected to exhibit a low level of polarization. The spatial power spectrum of the polarization can provide details about the formation of structure in the universe as well as its ionization history. Here we calculate the magnitude of the CMB polarization in various cosmological scenarios, with both an analytic and a numerical method. We then outline the fundemental challenges to measuring these signals and focus on two of them: achieving adequate sensitivity and removing contamination from foreground sources. We then describe the design of a ground based instrument (POLAR) that could detect polarization of the CMB at large angular scales in the new few years.Comment: 40 pages, 7 figures, accepted for publication in the Astrophysical Journa
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