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  1. Lauser, B.; Johannsen, G.; Caracciolo, C.; Hage, W.R. van; Keizer, J.; Mayr, P.: Comparing human and automatic thesaurus mapping approaches in the agricultural domain (2008) 0.03
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    Abstract
    Knowledge organization systems (KOS), like thesauri and other controlled vocabularies, are used to provide subject access to information systems across the web. Due to the heterogeneity of these systems, mapping between vocabularies becomes crucial for retrieving relevant information. However, mapping thesauri is a laborious task, and thus big efforts are being made to automate the mapping process. This paper examines two mapping approaches involving the agricultural thesaurus AGROVOC, one machine-created and one human created. We are addressing the basic question "What are the pros and cons of human and automatic mapping and how can they complement each other?" By pointing out the difficulties in specific cases or groups of cases and grouping the sample into simple and difficult types of mappings, we show the limitations of current automatic methods and come up with some basic recommendations on what approach to use when.
    Source
    Metadata for semantic and social applications : proceedings of the International Conference on Dublin Core and Metadata Applications, Berlin, 22 - 26 September 2008, DC 2008: Berlin, Germany / ed. by Jane Greenberg and Wolfgang Klas
  2. Lewandowski, D.; Mayr, P.: Exploring the academic invisible Web (2006) 0.02
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    Abstract
    Purpose: To provide a critical review of Bergman's 2001 study on the Deep Web. In addition, we bring a new concept into the discussion, the Academic Invisible Web (AIW). We define the Academic Invisible Web as consisting of all databases and collections relevant to academia but not searchable by the general-purpose internet search engines. Indexing this part of the Invisible Web is central to scien-tific search engines. We provide an overview of approaches followed thus far. Design/methodology/approach: Discussion of measures and calculations, estima-tion based on informetric laws. Literature review on approaches for uncovering information from the Invisible Web. Findings: Bergman's size estimate of the Invisible Web is highly questionable. We demonstrate some major errors in the conceptual design of the Bergman paper. A new (raw) size estimate is given. Research limitations/implications: The precision of our estimate is limited due to a small sample size and lack of reliable data. Practical implications: We can show that no single library alone will be able to index the Academic Invisible Web. We suggest collaboration to accomplish this task. Originality/value: Provides library managers and those interested in developing academic search engines with data on the size and attributes of the Academic In-visible Web.
    Content
    Bezug zu: Bergman, M.K.: The Deep Web: surfacing hidden value. In: Journal of Electronic Publishing. 7(2001) no.1, S.xxx-xxx. [Vgl. unter: http://www.press.umich.edu/jep/07-01/bergman.html].
  3. Lewandowski, D.; Mayr, P.: Exploring the academic invisible Web (2006) 0.02
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    Abstract
    Purpose: To provide a critical review of Bergman's 2001 study on the deep web. In addition, we bring a new concept into the discussion, the academic invisible web (AIW). We define the academic invisible web as consisting of all databases and collections relevant to academia but not searchable by the general-purpose internet search engines. Indexing this part of the invisible web is central to scientific search engines. We provide an overview of approaches followed thus far. Design/methodology/approach: Discussion of measures and calculations, estimation based on informetric laws. Literature review on approaches for uncovering information from the invisible web. Findings: Bergman's size estimate of the invisible web is highly questionable. We demonstrate some major errors in the conceptual design of the Bergman paper. A new (raw) size estimate is given. Research limitations/implications: The precision of our estimate is limited due to a small sample size and lack of reliable data. Practical implications: We can show that no single library alone will be able to index the academic invisible web. We suggest collaboration to accomplish this task. Originality/value: Provides library managers and those interested in developing academic search engines with data on the size and attributes of the academic invisible web.
  4. Daquino, M.; Peroni, S.; Shotton, D.; Colavizza, G.; Ghavimi, B.; Lauscher, A.; Mayr, P.; Romanello, M.; Zumstein, P.: ¬The OpenCitations Data Model (2020) 0.02
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    Abstract
    A variety of schemas and ontologies are currently used for the machine-readable description of bibliographic entities and citations. This diversity, and the reuse of the same ontology terms with different nuances, generates inconsistencies in data. Adoption of a single data model would facilitate data integration tasks regardless of the data supplier or context application. In this paper we present the OpenCitations Data Model (OCDM), a generic data model for describing bibliographic entities and citations, developed using Semantic Web technologies. We also evaluate the effective reusability of OCDM according to ontology evaluation practices, mention existing users of OCDM, and discuss the use and impact of OCDM in the wider open science community.
    Content
    Erschienen in: The Semantic Web - ISWC 2020, 19th International Semantic Web Conference, Athens, Greece, November 2-6, 2020, Proceedings, Part II. Vgl.: DOI: 10.1007/978-3-030-62466-8_28.
  5. Schaer, P.; Mayr, P.; Sünkler, S.; Lewandowski, D.: How relevant is the long tail? : a relevance assessment study on million short (2016) 0.01
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    Abstract
    Users of web search engines are known to mostly focus on the top ranked results of the search engine result page. While many studies support this well known information seeking pattern only few studies concentrate on the question what users are missing by neglecting lower ranked results. To learn more about the relevance distributions in the so-called long tail we conducted a relevance assessment study with the Million Short long-tail web search engine. While we see a clear difference in the content between the head and the tail of the search engine result list we see no statistical significant differences in the binary relevance judgments and weak significant differences when using graded relevance. The tail contains different but still valuable results. We argue that the long tail can be a rich source for the diversification of web search engine result lists but it needs more evaluation to clearly describe the differences.
  6. Mayr, P.; Petras, V.: Building a Terminology Network for Search : the KoMoHe project (2008) 0.01
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    Source
    Metadata for semantic and social applications : proceedings of the International Conference on Dublin Core and Metadata Applications, Berlin, 22 - 26 September 2008, DC 2008: Berlin, Germany / ed. by Jane Greenberg and Wolfgang Klas
  7. Mayr, P.; Mutschke, P.; Petras, V.: Reducing semantic complexity in distributed digital libraries : Treatment of term vagueness and document re-ranking (2008) 0.01
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    Footnote
    Beitrag eines Themenheftes "Digital libraries and the semantic web: context, applications and research".
    Theme
    Semantic Web
  8. Hobert, A.; Jahn, N.; Mayr, P.; Schmidt, B.; Taubert, N.: Open access uptake in Germany 2010-2018 : adoption in a diverse research landscape (2021) 0.01
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    Abstract
    Es handelt sich um eine bibliometrische Untersuchung der Entwicklung der Open-Access-Verfügbarkeit wissenschaftlicher Zeitschriftenartikel in Deutschland, die im Zeitraum 2010-18 erschienen und im Web of Science indexiert sind. Ein besonderes Augenmerk der Analyse lag auf der Frage, ob und inwiefern sich die Open-Access-Profile der Universitäten und außeruniversitären Wissenschaftseinrichtungen in Deutschland voneinander unterscheiden.
    Content
    This study investigates the development of open access (OA) to journal articles from authors affiliated with German universities and non-university research institutions in the period 2010-2018. Beyond determining the overall share of openly available articles, a systematic classification of distinct categories of OA publishing allowed us to identify different patterns of adoption of OA. Taking into account the particularities of the German research landscape, variations in terms of productivity, OA uptake and approaches to OA are examined at the meso-level and possible explanations are discussed. The development of the OA uptake is analysed for the different research sectors in Germany (universities, non-university research institutes of the Helmholtz Association, Fraunhofer Society, Max Planck Society, Leibniz Association, and government research agencies). Combining several data sources (incl. Web of Science, Unpaywall, an authority file of standardised German affiliation information, the ISSN-Gold-OA 3.0 list, and OpenDOAR), the study confirms the growth of the OA share mirroring the international trend reported in related studies. We found that 45% of all considered articles during the observed period were openly available at the time of analysis. Our findings show that subject-specific repositories are the most prevalent type of OA. However, the percentages for publication in fully OA journals and OA via institutional repositories show similarly steep increases. Enabling data-driven decision-making regarding the implementation of OA in Germany at the institutional level, the results of this study furthermore can serve as a baseline to assess the impact recent transformative agreements with major publishers will likely have on scholarly communication.
  9. Mayr, P.; Petras, V.; Walter, A.-K.: Results from a German terminology mapping effort : intra- and interdisciplinary cross-concordances between controlled vocabularies (2007) 0.01
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    Abstract
    In 2004, the German Federal Ministry for Education and Research funded a major terminology mapping initiative at the GESIS Social Science Information Centre in Bonn (GESIS-IZ), which will find its conclusion this year. The task of this terminology mapping initiative was to organize, create and manage 'crossconcordances' between major controlled vocabularies (thesauri, classification systems, subject heading lists) centred around the social sciences but quickly extending to other subject areas. Cross-concordances are intellectually (manually) created crosswalks that determine equivalence, hierarchy, and association relations between terms from two controlled vocabularies. Most vocabularies have been related bilaterally, that is, there is a cross-concordance relating terms from vocabulary A to vocabulary B as well as a cross-concordance relating terms from vocabulary B to vocabulary A (bilateral relations are not necessarily symmetrical). Till August 2007, 24 controlled vocabularies from 11 disciplines will be connected with vocabulary sizes ranging from 2,000 - 17,000 terms per vocabulary. To date more than 260,000 relations are generated. A database including all vocabularies and cross-concordances was built and a 'heterogeneity service' developed, a web service, which makes the cross-concordances available for other applications. Many cross-concordances are already implemented and utilized for the German Social Science Information Portal Sowiport (www.sowiport.de), which searches bibliographical and other information resources (incl. 13 databases with 10 different vocabularies and ca. 2.5 million references).