435 research outputs found

    Carbon stars in the X-shooter Spectral Library

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    We provide a new collection of spectra of 35 carbon stars obtained with the ESO/VLT X-shooter instrument as part of the X-shooter Spectral Library project. The spectra extend from 0.3μ\mum to 2.4μ\mum with a resolving power above \sim 8000. The sample contains stars with a broad range of (J-K) color and pulsation properties located in the Milky Way and the Magellanic Clouds. We show that the distribution of spectral properties of carbon stars at a given (J-K) color becomes bimodal (in our sample) when (J-K) is larger than about 1.5. We describe the two families of spectra that emerge, characterized by the presence or absence of the absorption feature at 1.53μ\mum, generally associated with HCN and C2_2H2_2. This feature appears essentially only in large-amplitude variables, though not in all observations. Associated spectral signatures that we interpret as the result of veiling by circumstellar matter, indicate that the 1.53μ\mum feature might point to episodes of dust production in carbon-rich Miras.Comment: 29 pages, 21 figures, 9 tables, Accepted for publication in A&

    Požadavky na XSL-FO verze 2.0

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    Tracking sub-page components in document workflows

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    Documents go through numerous transformations and intermediate formats as they are processed from abstract markup into final printable form. This notion of a document workflow is well established but it is common to find that ideas about document components, which might exist in the source code for the document, become completely lost within an amorphous, unstructured, page of PDF prior to being rendered. Given the importance of a component-based approach in Variable Data Printing (VDP) we have developed a collection of tools that allow information about the various transformations to be embedded at each stage in the workflow, together with a visualization tool that uses this embedded information to display the relationships between the various intermediate documents. In this paper, we demonstrate these tools in the context of an example document workflow but the techniques described are widely applicable and would be easily adaptable to other workflows and for use in teaching tools to illustrate document component and VDP concepts

    Social Statistics

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    Document Classification in Support of Automated Metadata Extraction Form Heterogeneous Collections

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    A number of federal agencies, universities, laboratories, and companies are placing their documents online and making them searchable via metadata fields such as author, title, and publishing organization. To enable this, every document in the collection must be catalogued using the metadata fields. Though time consuming, the task of identifying metadata fields by inspecting the document is easy for a human. The visual cues in the formatting of the document along with accumulated knowledge and intelligence make it easy for a human to identify various metadata fields. Even with the best possible automated procedures, numerous sources of error exist, including some that cannot be controlled, such as scanned documents with text obscured by smudges, signatures, or stamps. A commercially viable process for metadata extraction must remain robust in the presence of these external sources of error as well as in the face of the uncertainty that accompanies any attempts to automate intelligent behavior. While extraction accuracy and completeness must be the primary goal of an extraction system, the ability to detect and report questionable results is equally important for a production quality system, since it promotes confidence in the system. We have developed and demonstrated a novel system for extracting metadata. First, a document is examined in an attempt to recognize it as an instance of a known document layout. Then a template, a scripted description of how to associate blocks of text in the layout with metadata fields, is applied to the document to extract the metadata. The extraction is validated after post-processing to evaluate the quality of the extraction and, if necessary, to flag untrusted extractions for human recognition. The success or failure of the template approach is directly tied to document classification, which is the ability to match the document to the proper template correctly and consistently. Document classification in our system is implemented as a module which applies every template available in the system to a document to find candidate templates that extract any data at all. The candidate templates are evaluated by a validation module to select the best performing template. This method is called post hoc classification. Post hoc classification is not only effective at selecting the correct class but it also excels at minimizing false positives. It is, however, very sensitive to changes in the template collection and to poorly written templates. While this dissertation examines the evolution and all the major components of an automated metadata extraction system, the primary focus is on the problem of document classification. The main thrust of my research has been investigating alternative methods of document classification to replace or supplement post hoc classification. I experimented with machine learning techniques as an additional input factor for the post hoc classification script or the final validation script

    Towards a multimedia formatting vocabulary

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    Time-based, media-centric Web presentations can be described declaratively in the XML world through the development of languages such as SMIL. It is difficult, however, to fully integrate them in a complete document transformation processing chain. In order to achieve the desired processing of data-driven, time-based, media-centric presentations, the text-flow based formatting vocabularies used by style languages such as XSL, CSS and DSSSL need to be extended. The paper presents a selection of use cases which are used to derive a list of requirements for a multimedia style and transformation formatting vocabulary. The boundaries of applicability of existing text-based formatting models for media-centric transformations are analyzed. The paper then discusses the advantages and disadvantages of a fully-fledged time-based multimedia formatting model. Finally, the discussion is illustrated by describing the key properties of the example multimedia formatting vocabulary currently implemented in the back-end of our Cuypers multimedia transformation engine

    The use of data-mining for the automatic formation of tactics

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    This paper discusses the usse of data-mining for the automatic formation of tactics. It was presented at the Workshop on Computer-Supported Mathematical Theory Development held at IJCAR in 2004. The aim of this project is to evaluate the applicability of data-mining techniques to the automatic formation of tactics from large corpuses of proofs. We data-mine information from large proof corpuses to find commonly occurring patterns. These patterns are then evolved into tactics using genetic programming techniques

    Towards a multimedia formatting vocabulary

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    Time-based, media-centric Web presentations can be described declaratively in the XML world through the development of languages such as SMIL. It is difficult, however, to fully integrate them in a complete document transformation processing chain. In order to achieve the desired processing of data-driven, time-based, media-centric presentations, the text-flow based formatting vocabularies used by style languages such as XSL, CSS and DSSSL need to be extended. The paper presents a selection of use cases which are used to derive a list of requirements for a multimedia style and transformation formatting vocabulary. The boundaries of applicability of existing text-based formatting models for media-centric transformations are analyzed. The paper then discusses the advantages and disadvantages of a fully-fledged time-based multimedia formatting model. Finally, the discussion is illustrated by describing the key properties of the example multimedia formatting vocabulary currently implemented in the back-end of our Cuypers multimedia transformation engine

    Computational techniques for solar wind flows past terrestrial planets: Theory and computer programs

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    The interaction of the solar wind with terrestrial planets can be predicted using a computer program based on a single fluid, steady, dissipationless, magnetohydrodynamic model to calculate the axisymmetric, supersonic, super-Alfvenic solar wind flow past both magnetic and nonmagnetic planets. The actual calculations are implemented by an assemblage of computer codes organized into one program. These include finite difference codes which determine the gas-dynamic solution, together with a variety of special purpose output codes for determining and automatically plotting both flow field and magnetic field results. Comparisons are made with previous results, and results are presented for a number of solar wind flows. The computational programs developed are documented and are presented in a general user's manual which is included

    XML Integrated Environment for Service-Oriented Data Management

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    The proliferation of XML as a family of related standards including a markup language (XML), formatting semantics (XSL style sheets), a linking syntax (XLINK), and appropriate data schema standards have emerged as a de facto standard for encoding and sharing data between various applications. XML is designed to be simple, easily parsed and self-describing. XML is based on and support the idea of separation of concerns: information content is separated from information rendering, and relationships between data elements are provided via simple nesting and references. As the XML content grows, the ability to handle schemaless XML documents becomes more critical as most XML documents do not have schema or Document Type Definitions (DTDs). In addition, XML content and XML tools are often required to be combined in effective ways for better performance and higher flexibility. In this research, we proposed XML Integrated Environment (XIE) which is a general-purpose service-oriented architecture for processing XML documents in a scalable and efficient fashion. The XIE supports a new software service model that provides a proper abstraction to describe a service and divide it into four components: structure, connection, interface and logic. We also proposed and implemented XIE Service Language (XIESL) that can capture the creation and maintenance of the XML processes and the data flow specified by the user and then orchestrates the interactions between different XIE services. Moreover, XIESL manages the complexity of XML processing by implementing an XML processing pipeline that enables better management, control, interpretation and presentation of the XML data even for non-professional users. The XML Integrated Environment is envisioned to revolutionize the way non-professional programmers see, work and manage their XML assets. It offers them powerful tools and constructs to fully utilize the XML processing power embedded in its unified framework and service-oriented architecture
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