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Analysis of institutional authors

Luna-Jimenez, CristinaCorresponding AuthorEsteban-Romero, SergioAuthorGil-Martin, ManuelAuthor

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November 25, 2025
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Isolated German Sign Language Recognition for Classifying Polar Answers Using Landmarks and Lightweight Transformers

Publicated to: Applied Sciences-Basel. 15 (21): 11571- - 2025-10-29 15(21), DOI: 10.3390/app152111571

Authors:

Luna-Jimenez, Cristina; Eing, Lennart; Esteban-Romero, Sergio; Gil-Martin, Manuel; Andre, Elisabeth
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Affiliations

Univ Augsburg, Fac Appl Comp Sci, Chair Human Ctr Artificial Intelligence, D-86159 Augsburg, Germany - Author
Univ Politecn Madrid UPM, Grp Tecnol Habla & Aprendizaje Automat THAU Grp, Informat Proc & Telecommun Ctr, ETSI Telecomun, Madrid 28040, Spain - Author

Abstract

Sign Languages are the primary communication modality of deaf communities, yet building effective Isolated Sign Language Recognition (ISLR) systems remains difficult under data limitations. In this work, we curated a sub-dataset from the DGS-Korpus focused on recognizing affirmations and negations (polar answers) in German Sign Language (DGS). We designed lightweight transformer models using landmark-based inputs and evaluated them on two tasks: the binary classification of affirmations versus negations (binary semantic recognition) and the multi-class recognition of sign variations expressing positive or negative replies (multi-class gloss recognition). The main contribution of the article, hence, relies on the exploration of models for performing polar answer recognition in DGS and the exploration of differences between performing multi-class or binary class classification. Our best binary model achieved an accuracy of 97.71% using only hand landmarks without Positional Encoding, highlighting the potential of lightweight landmark-based transformers for efficient ISLR in constrained domains.
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Keywords

AccessibilityArtificial intelligenceClassification (of information)Communication modalitiesComputer interactionData limitationsElectric transformersHuman computer interactionHuman-computer interactionIsolated sign language recognitionLearning systemsMachine learningMachine-learningPattern recognitionRecognition systemsSemanticsSign languageSign language recognitionTransformerTransformers

Quality index

Bibliometric impact. Analysis of the contribution and dissemination channel

The work has been published in the journal Applied Sciences-Basel due to its progression and the good impact it has achieved in recent years, according to the agency WoS (JCR), it has become a reference in its field. In the year of publication of the work, 2025, it was in position 50/179, thus managing to position itself as a Q2 (Segundo Cuartil), in the category Engineering, Multidisciplinary. Notably, the journal is positioned en el Cuartil Q2 para la agencia Scopus (SJR) en la categoría Engineering (Miscellaneous).

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Impact and social visibility

From the perspective of influence or social adoption, and based on metrics associated with mentions and interactions provided by agencies specializing in calculating the so-called "Alternative or Social Metrics," we can highlight as of 2026-04-25:

  • The use of this contribution in bookmarks, code forks, additions to favorite lists for recurrent reading, as well as general views, indicates that someone is using the publication as a basis for their current work. This may be a notable indicator of future more formal and academic citations. This claim is supported by the result of the "Capture" indicator, which yields a total of: 2 (PlumX).

With a more dissemination-oriented intent and targeting more general audiences, we can observe other more global scores such as:

    It is essential to present evidence supporting full alignment with institutional principles and guidelines on Open Science and the Conservation and Dissemination of Intellectual Heritage. A clear example of this is:

    • The work has been submitted to a journal whose editorial policy allows open Open Access publication.
    • Assignment of a Handle/URN as an identifier within the deposit in the Institutional Repository: https://oa.upm.es/91700/

    As a result of the publication of the work in the institutional repository, statistical usage data has been obtained that reflects its impact. In terms of dissemination, we can state that, as of

    • Views: 58
    • Downloads: 64
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    Leadership analysis of institutional authors

    This work has been carried out with international collaboration, specifically with researchers from: Germany.

    There is a significant leadership presence as some of the institution’s authors appear as the first or last signer, detailed as follows: First Author (LUNA JIMENEZ, CRISTINA) .

    the author responsible for correspondence tasks has been LUNA JIMENEZ, CRISTINA.

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    Awards linked to the item

    This research was funded by the German Ministry for Education and Research (BMBF) through the BIGEKO project, grant number 16SV9094. Sergio Esteban-Romero's research was supported by the Spanish Ministry of Education (FPI grant PRE2022-105516). This work was partially funded by Project ASTOUND (101071191-HORIZON-EIC-2021-PATHFINDERCHALLENGES-01) of the European Commission and by the Spanish Ministry of Science and Innovation through the projects GOMINOLA (PID2020-118112RB-C22) funded by MCIN/AEI/10.13039/501100011033 and by the European Union "NextGenerationEU/PRTR".
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