Christian Chiarcos


2023

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Crowdsourcing OLiA Annotation Models the Indirect Way
Christian Chiarcos
Proceedings of the 4th Conference on Language, Data and Knowledge

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Towards ELTeC-LLOD: European Literary Text Collection Linguistic Linked Open Data
Ranka Stanković | Christian Chiarcos | Miloš Utvić | Olivera Kitanović
Proceedings of the 4th Conference on Language, Data and Knowledge

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Towards a Conversational Web? A Benchmark for Analysing Semantic Change with Conversational Knowledge Bots and Linked Open Data
Florentina Armaselu | Elena-Simona Apostol | Christian Chiarcos | Anas Fahad Khan | Chaya Liebeskind | Barbara McGillivray | Ciprian-Octavian Truica | Andrius Utka | Giedrė Valūnaitė-Oleškevičienė
Proceedings of the 4th Conference on Language, Data and Knowledge

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Validation of Language Agnostic Models for Discourse Marker Detection
Mariana Damova | Kostadin Mishev | Giedrė Valūnaitė-Oleškevičienė | Chaya Liebeskind | Purificação Silvano | Dimitar Trajanov | Ciprian-Octavian Truica | Elena-Simona Apostol | Christian Chiarcos | Anna Baczkowska
Proceedings of the 4th Conference on Language, Data and Knowledge

2022

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Cross-Lingual Link Discovery for Under-Resourced Languages
Michael Rosner | Sina Ahmadi | Elena-Simona Apostol | Julia Bosque-Gil | Christian Chiarcos | Milan Dojchinovski | Katerina Gkirtzou | Jorge Gracia | Dagmar Gromann | Chaya Liebeskind | Giedrė Valūnaitė Oleškevičienė | Gilles Sérasset | Ciprian-Octavian Truică
Proceedings of the Thirteenth Language Resources and Evaluation Conference

In this paper, we provide an overview of current technologies for cross-lingual link discovery, and we discuss challenges, experiences and prospects of their application to under-resourced languages. We rst introduce the goals of cross-lingual linking and associated technologies, and in particular, the role that the Linked Data paradigm (Bizer et al., 2011) applied to language data can play in this context. We de ne under-resourced languages with a speci c focus on languages actively used on the internet, i.e., languages with a digitally versatile speaker community, but limited support in terms of language technology. We argue that languages for which considerable amounts of textual data and (at least) a bilingual word list are available, techniques for cross-lingual linking can be readily applied, and that these enable the implementation of downstream applications for under-resourced languages via the localisation and adaptation of existing technologies and resources.

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Inducing Discourse Marker Inventories from Lexical Knowledge Graphs
Christian Chiarcos
Proceedings of the Thirteenth Language Resources and Evaluation Conference

Discourse marker inventories are important tools for the development of both discourse parsers and corpora with discourse annotations. In this paper we explore the potential of massively multilingual lexical knowledge graphs to induce multilingual discourse marker lexicons using concept propagation methods as previously developed in the context of translation inference across dictionaries. Given one or multiple source languages with discourse marker inventories that discourse relations as senses of potential discourse markers, as well as a large number of bilingual dictionaries that link them – directly or indirectly – with the target language, we specifically study to what extent discourse marker induction can benefit from the integration of information from different sources, the impact of sense granularity and what limiting factors may need to be considered. Our study uses discourse marker inventories from nine European languages normalized against the discourse relation inventory of the Penn Discourse Treebank (PDTB), as well as three collections of machine-readable dictionaries with different characteristics, so that the interplay of a large number of factors can be studied.

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ISO-based Annotated Multilingual Parallel Corpus for Discourse Markers
Purificação Silvano | Mariana Damova | Giedrė Valūnaitė Oleškevičienė | Chaya Liebeskind | Christian Chiarcos | Dimitar Trajanov | Ciprian-Octavian Truică | Elena-Simona Apostol | Anna Baczkowska
Proceedings of the Thirteenth Language Resources and Evaluation Conference

Discourse markers carry information about the discourse structure and organization, and also signal local dependencies or epistemological stance of speaker. They provide instructions on how to interpret the discourse, and their study is paramount to understand the mechanism underlying discourse organization. This paper presents a new language resource, an ISO-based annotated multilingual parallel corpus for discourse markers. The corpus comprises nine languages, Bulgarian, Lithuanian, German, European Portuguese, Hebrew, Romanian, Polish, and Macedonian, with English as a pivot language. In order to represent the meaning of the discourse markers, we propose an annotation scheme of discourse relations from ISO 24617-8 with a plug-in to ISO 24617-2 for communicative functions. We describe an experiment in which we applied the annotation scheme to assess its validity. The results reveal that, although some extensions are required to cover all the multilingual data, it provides a proper representation of discourse markers value. Additionally, we report some relevant contrastive phenomena concerning discourse markers interpretation and role in discourse. This first step will allow us to develop deep learning methods to identify and extract discourse relations and communicative functions, and to represent that information as Linguistic Linked Open Data (LLOD).

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Querying a Dozen Corpora and a Thousand Years with Fintan
Christian Chiarcos | Christian Fäth | Maxim Ionov
Proceedings of the Thirteenth Language Resources and Evaluation Conference

Large-scale diachronic corpus studies covering longer time periods are difficult if more than one corpus are to be consulted and, as a result, different formats and annotation schemas need to be processed and queried in a uniform, comparable and replicable manner. We describes the application of the Flexible Integrated Transformation and Annotation eNgineering (Fintan) platform for studying word order in German using syntactically annotated corpora that represent its entire written history. Focusing on nominal dative and accusative arguments, this study hints at two major phases in the development of scrambling in modern German. Against more recent assumptions, it supports the traditional view that word order flexibility decreased over time, but it also indicates that this was a relatively sharp transition in Early New High German. The successful case study demonstrates the potential of Fintan and the underlying LLOD technology for historical linguistics, linguistic typology and corpus linguistics. The technological contribution of this paper is to demonstrate the applicability of Fintan for querying across heterogeneously annotated corpora, as previously, it had only been applied for transformation tasks. With its focus on quantitative analysis, Fintan is a natural complement for existing multi-layer technologies that focus on query and exploration.

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Unifying Morphology Resources with OntoLex-Morph. A Case Study in German
Christian Chiarcos | Christian Fäth | Maxim Ionov
Proceedings of the Thirteenth Language Resources and Evaluation Conference

The OntoLex vocabulary has become a widely used community standard for machine-readable lexical resources on the web. The primary motivation to use OntoLex in favor of tool- or application-specific formalisms is to facilitate interoperability and information integration across different resources. One of its extension that is currently being developed is a module for representing morphology, OntoLex-Morph. In this paper, we show how OntoLex-Morph can be used for the encoding and integration of different types of morphological resources on a unified basis. With German as the example, we demonstrate it for (a) a full-form dictionary with inflection information (Unimorph), (b) a dictionary of base forms and their derivations (UDer), (c) a dictionary of compounds (from GermaNet), and (d) lexicon and inflection rules of a finite-state parser/generator (SMOR/Morphisto). These data are converted to OntoLex-Morph, their linguistic information is consolidated and corresponding lexical entries are linked with each other.

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Modelling Collocations in OntoLex-FrAC
Christian Chiarcos | Katerina Gkirtzou | Maxim Ionov | Besim Kabashi | Fahad Khan | Ciprian-Octavian Truică
Proceedings of Globalex Workshop on Linked Lexicography within the 13th Language Resources and Evaluation Conference

Following presentations of frequency and attestations, and embeddings and distributional similarity, this paper introduces the third cornerstone of the emerging OntoLex module for Frequency, Attestation and Corpus-based Information, OntoLex-FrAC. We provide an RDF vocabulary for collocations, established as a consensus over contributions from five different institutions and numerous data sets, with the goal of eliciting feedback from reviewers, workshop audience and the scientific community in preparation of the final consolidation of the OntoLex-FrAC module, whose publication as a W3C community report is foreseen for the end of this year. The novel collocation component of OntoLex-FrAC is described in application to a lexicographic resource and corpus-based collocation scores available from the web, and finally, we demonstrate the capability and genericity of the model by showing how to retrieve and aggregate collocation information by means of SPARQL, and its export to a tabular format, so that it can be easily processed in downstream applications.

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Proceedings of the 8th Workshop on Linked Data in Linguistics within the 13th Language Resources and Evaluation Conference
Thierry Declerck | John P. McCrae | Elena Montiel | Christian Chiarcos | Maxim Ionov
Proceedings of the 8th Workshop on Linked Data in Linguistics within the 13th Language Resources and Evaluation Conference

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A Cheap and Dirty Cross-Lingual Linking Service in the Cloud
Christian Chiarcos | Gilles Sérasset
Proceedings of the 8th Workshop on Linked Data in Linguistics within the 13th Language Resources and Evaluation Conference

In this paper, we describe the application of Linguistic Linked Open Data (LLOD) technology for dynamic cross-lingual querying on demand. Whereas most related research is focusing on providing a static linking, i.e., cross-lingual inference, and then storing the resulting links, we demonstrate the application of the federation capabilities of SPARQL to perform lexical linking on the fly. In the end, we provide a baseline functionality that uses the connection of two web services – a SPARQL end point for multilingual lexical data and another SPARQL end point for querying an English language knowledge graph – in order to perform querying an English language knowledge graph using foreign language labels. We argue that, for low-resource languages where substantial native knowledge graphs are lacking, this functionality can be used to lower the language barrier by allowing to formulate cross-linguistically applicable queries mediated by a multilingual dictionary.

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Spicy Salmon: Converting between 50+ Annotation Formats with Fintan, Pepper, Salt and Powla
Christian Fäth | Christian Chiarcos
Proceedings of the 8th Workshop on Linked Data in Linguistics within the 13th Language Resources and Evaluation Conference

Heterogeneity of formats, models and annotations has always been a primary hindrance for exploiting the ever increasing amount of existing linguistic resources for real world applications in and beyond NLP. Fintan - the Flexible INtegrated Transformation and Annotation eNgineering platform introduced in 2020 is designed to rapidly convert, combine and manipulate language resources both in and outside the Semantic Web by transforming it into segmented RDF representations which can be processed in parallel on a multithreaded environment and integrating it with ontologies and taxonomies. Fintan has recently been extended with a set of additional modules increasing the amount of supported non-RDF formats and the interoperability with existing non-JAVA conversion tools, and parts of this work are demonstrated in this paper. In particular, we focus on a novel recipe for resource transformation in which Fintan works in tandem with the Pepper toolset to allow computational linguists to transform their data between over 50 linguistic corpus formats with a graphical workflow manager.

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A Survey of Guidelines and Best Practices for the Generation, Interlinking, Publication, and Validation of Linguistic Linked Data
Fahad Khan | Christian Chiarcos | Thierry Declerck | Maria Pia Di Buono | Milan Dojchinovski | Jorge Gracia | Giedre Valunaite Oleskeviciene | Daniela Gifu
Proceedings of the 8th Workshop on Linked Data in Linguistics within the 13th Language Resources and Evaluation Conference

This article discusses a survey carried out within the NexusLinguarum COST Action which aimed to give an overview of existing guidelines (GLs) and best practices (BPs) in linguistic linked data. In particular it focused on four core tasks in the production/publication of linked data: generation, interlinking, publication, and validation. We discuss the importance of GLs and BPs for LLD before describing the survey and its results in full. Finally we offer a number of directions for future work in order to address the findings of the survey.

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Computational Morphology with OntoLex-Morph
Christian Chiarcos | Katerina Gkirtzou | Fahad Khan | Penny Labropoulou | Marco Passarotti | Matteo Pellegrini
Proceedings of the 8th Workshop on Linked Data in Linguistics within the 13th Language Resources and Evaluation Conference

This paper describes the current status of the emerging OntoLex module for linguistic morphology. It serves as an update to the previous version of the vocabulary (Klimek et al. 2019). Whereas this earlier model was exclusively focusing on descriptive morphology and focused on applications in lexicography, we now present a novel part and a novel application of the vocabulary to applications in language technology, i.e., the rule-based generation of lexicons, introducing a dynamic component into OntoLex.

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Modelling Frequency, Attestation, and Corpus-Based Information with OntoLex-FrAC
Christian Chiarcos | Elena-Simona Apostol | Besim Kabashi | Ciprian-Octavian Truică
Proceedings of the 29th International Conference on Computational Linguistics

OntoLex-Lemon has become a de facto standard for lexical resources in the web of data. This paper provides the first overall description of the emerging OntoLex module for Frequency, Attestations, and Corpus-Based Information (OntoLex-FrAC) that is intended to complement OntoLex-Lemon with the necessary vocabulary to represent major types of information found in or automatically derived from corpora, for applications in both language technology and the language sciences.

2021

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Embeddings for the Lexicon: Modelling and Representation
Christian Chiarcos | Thierry Declerck | Maxim Ionov
Proceedings of the 6th Workshop on Semantic Deep Learning (SemDeep-6)

2020

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On the Linguistic Linked Open Data Infrastructure
Christian Chiarcos | Bettina Klimek | Christian Fäth | Thierry Declerck | John Philip McCrae
Proceedings of the 1st International Workshop on Language Technology Platforms

In this paper we describe the current state of development of the Linguistic Linked Open Data (LLOD) infrastructure, an LOD(sub-)cloud of linguistic resources, which covers various linguistic data bases, lexicons, corpora, terminology and metadata repositories. We give in some details an overview of the contributions made by the European H2020 projects “Prêt-à-LLOD” (‘Ready-to-useMultilingual Linked Language Data for Knowledge Services across Sectors’) and “ELEXIS” (‘European Lexicographic Infrastructure’) to the further development of the LLOD.

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Towards an Interoperable Ecosystem of AI and LT Platforms: A Roadmap for the Implementation of Different Levels of Interoperability
Georg Rehm | Dimitris Galanis | Penny Labropoulou | Stelios Piperidis | Martin Welß | Ricardo Usbeck | Joachim Köhler | Miltos Deligiannis | Katerina Gkirtzou | Johannes Fischer | Christian Chiarcos | Nils Feldhus | Julian Moreno-Schneider | Florian Kintzel | Elena Montiel | Víctor Rodríguez Doncel | John Philip McCrae | David Laqua | Irina Patricia Theile | Christian Dittmar | Kalina Bontcheva | Ian Roberts | Andrejs Vasiļjevs | Andis Lagzdiņš
Proceedings of the 1st International Workshop on Language Technology Platforms

With regard to the wider area of AI/LT platform interoperability, we concentrate on two core aspects: (1) cross-platform search and discovery of resources and services; (2) composition of cross-platform service workflows. We devise five different levels (of increasing complexity) of platform interoperability that we suggest to implement in a wider federation of AI/LT platforms. We illustrate the approach using the five emerging AI/LT platforms AI4EU, ELG, Lynx, QURATOR and SPEAKER.

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The ACoLi Dictionary Graph
Christian Chiarcos | Christian Fäth | Maxim Ionov
Proceedings of the Twelfth Language Resources and Evaluation Conference

In this paper, we report the release of the ACoLi Dictionary Graph, a large-scale collection of multilingual open source dictionaries available in two machine-readable formats, a graph representation in RDF, using the OntoLex-Lemon vocabulary, and a simple tabular data format to facilitate their use in NLP tasks, such as translation inference across dictionaries. We describe the mapping and harmonization of the underlying data structures into a unified representation, its serialization in RDF and TSV, and the release of a massive and coherent amount of lexical data under open licenses.

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Recent Developments for the Linguistic Linked Open Data Infrastructure
Thierry Declerck | John Philip McCrae | Matthias Hartung | Jorge Gracia | Christian Chiarcos | Elena Montiel-Ponsoda | Philipp Cimiano | Artem Revenko | Roser Saurí | Deirdre Lee | Stefania Racioppa | Jamal Abdul Nasir | Matthias Orlikowsk | Marta Lanau-Coronas | Christian Fäth | Mariano Rico | Mohammad Fazleh Elahi | Maria Khvalchik | Meritxell Gonzalez | Katharine Cooney
Proceedings of the Twelfth Language Resources and Evaluation Conference

In this paper we describe the contributions made by the European H2020 project “Prêt-à-LLOD” (‘Ready-to-use Multilingual Linked Language Data for Knowledge Services across Sectors’) to the further development of the Linguistic Linked Open Data (LLOD) infrastructure. Prêt-à-LLOD aims to develop a new methodology for building data value chains applicable to a wide range of sectors and applications and based around language resources and language technologies that can be integrated by means of semantic technologies. We describe the methods implemented for increasing the number of language data sets in the LLOD. We also present the approach for ensuring interoperability and for porting LLOD data sets and services to other infrastructures, as well as the contribution of the projects to existing standards.

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Annotation Interoperability for the Post-ISOCat Era
Christian Chiarcos | Christian Fäth | Frank Abromeit
Proceedings of the Twelfth Language Resources and Evaluation Conference

With this paper, we provide an overview over ISOCat successor solutions and annotation standardization efforts since 2010, and we describe the low-cost harmonization of post-ISOCat vocabularies by means of modular, linked ontologies: The CLARIN Concept Registry, LexInfo, Universal Parts of Speech, Universal Dependencies and UniMorph are linked with the Ontologies of Linguistic Annotation and through it with ISOCat, the GOLD ontology, the Typological Database Systems ontology and a large number of annotation schemes.

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A Tree Extension for CoNLL-RDF
Christian Chiarcos | Luis Glaser
Proceedings of the Twelfth Language Resources and Evaluation Conference

The technological bridges between knowledge graphs and natural language processing are of utmost importance for the future development of language technology. CoNLL-RDF is a technology that provides such a bridge for popular one-word-per-line formats as widely used in NLP (e.g., the CoNLL Shared Tasks), annotation (Universal Dependencies, Unimorph), corpus linguistics (Corpus WorkBench, CWB) and digital lexicography (SketchEngine): Every empty-line separated table (usually a sentence) is parsed into an graph, can be freely manipulated and enriched using W3C-standardized RDF technology, and then be serialized back into in a TSV format, RDF or other formats. An important limitation is that CoNLL-RDF provides native support for word-level annotations only. This does include dependency syntax and semantic role annotations, but neither phrase structures nor text structure. We describe the extension of the CoNLL-RDF technology stack for two vocabulary extensions of CoNLL-TSV, the PTB bracket notation used in earlier CoNLL Shared Tasks and the extension with XML markup elements featured by CWB and SketchEngine. In order to represent the necessary extensions of the CoNLL vocabulary in an adequate fashion, we employ the POWLA vocabulary for representing and navigating in tree structures.

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Fintan - Flexible, Integrated Transformation and Annotation eNgineering
Christian Fäth | Christian Chiarcos | Björn Ebbrecht | Maxim Ionov
Proceedings of the Twelfth Language Resources and Evaluation Conference

We introduce the Flexible and Integrated Transformation and Annotation eNgeneering (Fintan) platform for converting heterogeneous linguistic resources to RDF. With its modular architecture, workflow management and visualization features, Fintan facilitates the development of complex transformation pipelines by integrating generic RDF converters and augmenting them with extended graph processing capabilities: Existing converters can be easily deployed to the system by means of an ontological data structure which renders their properties and the dependencies between transformation steps. Development of subsequent graph transformation steps for resource transformation, annotation engineering or entity linking is further facilitated by a novel visual rendering of SPARQL queries. A graphical workflow manager allows to easily manage the converter modules and combine them to new transformation pipelines. Employing the stream-based graph processing approach first implemented with CoNLL-RDF, we address common challenges and scalability issues when transforming resources and showcase the performance of Fintan by means of a purely graph-based transformation of the Universal Morphology data to RDF.

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Proceedings of the 7th Workshop on Linked Data in Linguistics (LDL-2020)
Maxim Ionov | John P. McCrae | Christian Chiarcos | Thierry Declerck | Julia Bosque-Gil | Jorge Gracia
Proceedings of the 7th Workshop on Linked Data in Linguistics (LDL-2020)

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Towards the First Machine Translation System for Sumerian Transliterations
Ravneet Punia | Niko Schenk | Christian Chiarcos | Émilie Pagé-Perron
Proceedings of the 28th International Conference on Computational Linguistics

The Sumerian cuneiform script was invented more than 5,000 years ago and represents one of the oldest in history. We present the first attempt to translate Sumerian texts into English automatically. We publicly release high-quality corpora for standardized training and evaluation and report results on experiments with supervised, phrase-based, and transfer learning techniques for machine translation. Quantitative and qualitative evaluations indicate the usefulness of the translations. Our proposed methodology provides a broader audience of researchers with novel access to the data, accelerates the costly and time-consuming manual translation process, and helps them better explore the relationships between Sumerian cuneiform and Mesopotamian culture.

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Modelling Frequency and Attestations for OntoLex-Lemon
Christian Chiarcos | Maxim Ionov | Jesse de Does | Katrien Depuydt | Anas Fahad Khan | Sander Stolk | Thierry Declerck | John Philip McCrae
Proceedings of the 2020 Globalex Workshop on Linked Lexicography

The OntoLex vocabulary enjoys increasing popularity as a means of publishing lexical resources with RDF and as Linked Data. The recent publication of a new OntoLex module for lexicography, lexicog, reflects its increasing importance for digital lexicography. However, not all aspects of digital lexicography have been covered to the same extent. In particular, supplementary information drawn from corpora such as frequency information, links to attestations, and collocation data were considered to be beyond the scope of lexicog. Therefore, the OntoLex community has put forward the proposal for a novel module for frequency, attestation and corpus information (FrAC), that not only covers the requirements of digital lexicography, but also accommodates essential data structures for lexical information in natural language processing. This paper introduces the current state of the OntoLex-FrAC vocabulary, describes its structure, some selected use cases, elementary concepts and fundamental definitions, with a focus on frequency and attestations.

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Translation Inference by Concept Propagation
Christian Chiarcos | Niko Schenk | Christian Fäth
Proceedings of the 2020 Globalex Workshop on Linked Lexicography

This paper describes our contribution to the Third Shared Task on Translation Inference across Dictionaries (TIAD-2020). We describe an approach on translation inference based on symbolic methods, the propagation of concepts over a graph of interconnected dictionaries: Given a mapping from source language words to lexical concepts (e.g., synsets) as a seed, we use bilingual dictionaries to extrapolate a mapping of pivot and target language words to these lexical concepts. Translation inference is then performed by looking up the lexical concept(s) of a source language word and returning the target language word(s) for which these lexical concepts have the respective highest score. We present two instantiations of this system: One using WordNet synsets as concepts, and one using lexical entries (translations) as concepts. With a threshold of 0, the latter configuration is the second among participant systems in terms of F1 score. We also describe additional evaluation experiments on Apertium data, a comparison with an earlier approach based on embedding projection, and an approach for constrained projection that outperforms the TIAD-2020 vanilla system by a large margin.

2018

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The ACoLi CoNLL Libraries: Beyond Tab-Separated Values
Christian Chiarcos | Niko Schenk
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Towards a Linked Open Data Edition of Sumerian Corpora
Christian Chiarcos | Émilie Pagé-Perron | Ilya Khait | Niko Schenk | Lucas Reckling
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Universal Morphologies for the Caucasus region
Christian Chiarcos | Kathrin Donandt | Maxim Ionov | Monika Rind-Pawlowski | Hasmik Sargsian | Jesse Wichers Schreur | Frank Abromeit | Christian Fäth
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Analyzing Middle High German Syntax with RDF and SPARQL
Christian Chiarcos | Benjamin Kosmehl | Christian Fäth | Maria Sukhareva
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

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Interoperability of Language-related Information: Mapping the BLL Thesaurus to Lexvo and Glottolog
Vanya Dimitrova | Christian Fäth | Christian Chiarcos | Heike Renner-Westermann | Frank Abromeit
Proceedings of the Eleventh International Conference on Language Resources and Evaluation (LREC 2018)

2017

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A Recurrent Neural Model with Attention for the Recognition of Chinese Implicit Discourse Relations
Samuel Rönnqvist | Niko Schenk | Christian Chiarcos
Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

We introduce an attention-based Bi-LSTM for Chinese implicit discourse relations and demonstrate that modeling argument pairs as a joint sequence can outperform word order-agnostic approaches. Our model benefits from a partial sampling scheme and is conceptually simple, yet achieves state-of-the-art performance on the Chinese Discourse Treebank. We also visualize its attention activity to illustrate the model’s ability to selectively focus on the relevant parts of an input sequence.

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Resource-Lean Modeling of Coherence in Commonsense Stories
Niko Schenk | Christian Chiarcos
Proceedings of the 2nd Workshop on Linking Models of Lexical, Sentential and Discourse-level Semantics

We present a resource-lean neural recognizer for modeling coherence in commonsense stories. Our lightweight system is inspired by successful attempts to modeling discourse relations and stands out due to its simplicity and easy optimization compared to prior approaches to narrative script learning. We evaluate our approach in the Story Cloze Test demonstrating an absolute improvement in accuracy of 4.7% over state-of-the-art implementations.

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Machine Translation and Automated Analysis of the Sumerian Language
Émilie Pagé-Perron | Maria Sukhareva | Ilya Khait | Christian Chiarcos
Proceedings of the Joint SIGHUM Workshop on Computational Linguistics for Cultural Heritage, Social Sciences, Humanities and Literature

This paper presents a newly funded international project for machine translation and automated analysis of ancient cuneiform languages where NLP specialists and Assyriologists collaborate to create an information retrieval system for Sumerian. This research is conceived in response to the need to translate large numbers of administrative texts that are only available in transcription, in order to make them accessible to a wider audience. The methodology includes creation of a specialized NLP pipeline and also the use of linguistic linked open data to increase access to the results.

2016

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Do We Really Need All Those Rich Linguistic Features? A Neural Network-Based Approach to Implicit Sense Labeling
Niko Schenk | Christian Chiarcos | Kathrin Donandt | Samuel Rönnqvist | Evgeny Stepanov | Giuseppe Riccardi
Proceedings of the CoNLL-16 shared task

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Unsupervised Learning of Prototypical Fillers for Implicit Semantic Role Labeling
Niko Schenk | Christian Chiarcos
Proceedings of the 2016 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies

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Corpora and Linguistic Linked Open Data: Motivations, Applications, Limitations
Christian Chiarcos
Actes de la conférence conjointe JEP-TALN-RECITAL 2016. Volume 4 : Conférences invitées

Linguistic Linked Open Data (LLOD) is a technology and a movement in several disciplines working with language resources, including Natural Language Processing, general linguistics, computational lexicography and the localization industry. This talk describes basic principles of Linguistic Linked Open Data and their application to linguistically annotated corpora, it summarizes the current status of the Linguistic Linked Open Data cloud and gives an overview over selected LLOD vocabularies and their uses.

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Combining Ontologies and Neural Networks for Analyzing Historical Language Varieties. A Case Study in Middle Low German
Maria Sukhareva | Christian Chiarcos
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

In this paper, we describe experiments on the morphosyntactic annotation of historical language varieties for the example of Middle Low German (MLG), the official language of the German Hanse during the Middle Ages and a dominant language around the Baltic Sea by the time. To our best knowledge, this is the first experiment in automatically producing morphosyntactic annotations for Middle Low German, and accordingly, no part-of-speech (POS) tagset is currently agreed upon. In our experiment, we illustrate how ontology-based specifications of projected annotations can be employed to circumvent this issue: Instead of training and evaluating against a given tagset, we decomponse it into independent features which are predicted independently by a neural network. Using consistency constraints (axioms) from an ontology, then, the predicted feature probabilities are decoded into a sound ontological representation. Using these representations, we can finally bootstrap a POS tagset capturing only morphosyntactic features which could be reliably predicted. In this way, our approach is capable to optimize precision and recall of morphosyntactic annotations simultaneously with bootstrapping a tagset rather than performing iterative cycles.

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The Open Linguistics Working Group: Developing the Linguistic Linked Open Data Cloud
John Philip McCrae | Christian Chiarcos | Francis Bond | Philipp Cimiano | Thierry Declerck | Gerard de Melo | Jorge Gracia | Sebastian Hellmann | Bettina Klimek | Steven Moran | Petya Osenova | Antonio Pareja-Lora | Jonathan Pool
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

The Open Linguistics Working Group (OWLG) brings together researchers from various fields of linguistics, natural language processing, and information technology to present and discuss principles, case studies, and best practices for representing, publishing and linking linguistic data collections. A major outcome of our work is the Linguistic Linked Open Data (LLOD) cloud, an LOD (sub-)cloud of linguistic resources, which covers various linguistic databases, lexicons, corpora, terminologies, and metadata repositories. We present and summarize five years of progress on the development of the cloud and of advancements in open data in linguistics, and we describe recent community activities. The paper aims to serve as a guideline to orient and involve researchers with the community and/or Linguistic Linked Open Data.

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Word Segmentation for Akkadian Cuneiform
Timo Homburg | Christian Chiarcos
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

We present experiments on word segmentation for Akkadian cuneiform, an ancient writing system and a language used for about 3 millennia in the ancient Near East. To our best knowledge, this is the first study of this kind applied to either the Akkadian language or the cuneiform writing system. As a logosyllabic writing system, cuneiform structurally resembles Eastern Asian writing systems, so, we employ word segmentation algorithms originally developed for Chinese and Japanese. We describe results of rule-based algorithms, dictionary-based algorithms, statistical and machine learning approaches. Our results may indicate possible promising steps in cuneiform word segmentation that can create and improve natural language processing in this area.

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Lin|gu|is|tik: Building the Linguist’s Pathway to Bibliographies, Libraries, Language Resources and Linked Open Data
Christian Chiarcos | Christian Fäth | Heike Renner-Westermann | Frank Abromeit | Vanya Dimitrova
Proceedings of the Tenth International Conference on Language Resources and Evaluation (LREC'16)

This paper introduces a novel research tool for the field of linguistics: The Lin|gu|is|tik web portal provides a virtual library which offers scientific information on every linguistic subject. It comprises selected internet sources and databases as well as catalogues for linguistic literature, and addresses an interdisciplinary audience. The virtual library is the most recent outcome of the Special Subject Collection Linguistics of the German Research Foundation (DFG), and also integrates the knowledge accumulated in the Bibliography of Linguistic Literature. In addition to the portal, we describe long-term goals and prospects with a special focus on ongoing efforts regarding an extension towards integrating language resources and Linguistic Linked Open Data.

2015

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Towards the Unsupervised Acquisition of Implicit Semantic Roles
Niko Schenk | Christian Chiarcos | Maria Sukhareva
Proceedings of the International Conference Recent Advances in Natural Language Processing

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A Minimalist Approach to Shallow Discourse Parsing and Implicit Relation Recognition
Christian Chiarcos | Niko Schenk
Proceedings of the Nineteenth Conference on Computational Natural Language Learning - Shared Task

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Proceedings of the 4th Workshop on Linked Data in Linguistics: Resources and Applications
Christian Chiarcos | John Philip McCrae | Petya Osenova | Philipp Cimiano | Nancy Ide
Proceedings of the 4th Workshop on Linked Data in Linguistics: Resources and Applications

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Memory-Based Acquisition of Argument Structures and its Application to Implicit Role Detection
Christian Chiarcos | Niko Schenk
Proceedings of the 16th Annual Meeting of the Special Interest Group on Discourse and Dialogue

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An Ontology-based Approach To Automatic Part-of-Speech Tagging Using Heterogeneously Annotated Corpora
Maria Sukhareva | Christian Chiarcos
Proceedings of the Second Workshop on Natural Language Processing and Linked Open Data

2014

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New Technologies for Old Germanic. Resources and Research on Parallel Bibles in Older Continental Western Germanic
Christian Chiarcos | Maria Sukhareva | Roland Mittmann | Timothy Price | Gaye Detmold | Jan Chobotsky
Proceedings of the 8th Workshop on Language Technology for Cultural Heritage, Social Sciences, and Humanities (LaTeCH)

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Diachronic proximity vs. data sparsity in cross-lingual parser projection. A case study on Germanic
Maria Sukhareva | Christian Chiarcos
Proceedings of the First Workshop on Applying NLP Tools to Similar Languages, Varieties and Dialects

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Towards interoperable discourse annotation. Discourse features in the Ontologies of Linguistic Annotation
Christian Chiarcos
Proceedings of the Ninth International Conference on Language Resources and Evaluation (LREC'14)

This paper describes the extension of the Ontologies of Linguistic Annotation (OLiA) with respect to discourse features. The OLiA ontologies provide a a terminology repository that can be employed to facilitate the conceptual (semantic) interoperability of annotations of discourse phenomena as found in the most important corpora available to the community, including OntoNotes, the RST Discourse Treebank and the Penn Discourse Treebank. Along with selected schemes for information structure and coreference, discourse relations are discussed with special emphasis on the Penn Discourse Treebank and the RST Discourse Treebank. For an example contained in the intersection of both corpora, I show how ontologies can be employed to generalize over divergent annotation schemes.

2013

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Linguistic Linked Open Data (LLOD) – Building the cloud
Christian Chiarcos
Proceedings of the Joint Workshop on NLP&LOD and SWAIE: Semantic Web, Linked Open Data and Information Extraction

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Proceedings of the 2nd Workshop on Linked Data in Linguistics (LDL-2013): Representing and linking lexicons, terminologies and other language data
Christian Chiarcos | Philipp Cimiano | Thierry Declerck | John P. McCrae
Proceedings of the 2nd Workshop on Linked Data in Linguistics (LDL-2013): Representing and linking lexicons, terminologies and other language data

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Linguistic Linked Open Data (LLOD). Introduction and Overview
Christian Chiarcos | Philipp Cimiano | Thierry Declerck | John P. McCrae
Proceedings of the 2nd Workshop on Linked Data in Linguistics (LDL-2013): Representing and linking lexicons, terminologies and other language data

2012

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Towards the Unsupervised Acquisition of Discourse Relations
Christian Chiarcos
Proceedings of the 50th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

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Ontologies of Linguistic Annotation: Survey and perspectives
Christian Chiarcos
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

This paper announces the release of the Ontologies of Linguistic Annotation (OLiA). The OLiA ontologies represent a repository of annotation terminology for various linguistic phenomena on a great band-width of languages. This paper summarizes the results of five years of research, it describes recent developments and directions for further research.

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The Open Linguistics Working Group
Christian Chiarcos | Sebastian Hellmann | Sebastian Nordhoff | Steven Moran | Richard Littauer | Judith Eckle-Kohler | Iryna Gurevych | Silvana Hartmann | Michael Matuschek | Christian M. Meyer
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

This paper describes the Open Linguistics Working Group (OWLG) of the Open Knowledge Foundation (OKFN). The OWLG is an initiative concerned with linguistic data by scholars from diverse fields, including linguistics, NLP, and information science. The primary goal of the working group is to promote the idea of open linguistic resources, to develop means for their representation and to encourage the exchange of ideas across different disciplines. This paper summarizes the progress of the working group, goals that have been identified, problems that we are going to address, and recent activities and ongoing developments. Here, we put particular emphasis on the development of a Linked Open Data (sub-)cloud of linguistic resources that is currently being pursued by several OWLG members.

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A generic formalism to represent linguistic corpora in RDF and OWL/DL
Christian Chiarcos
Proceedings of the Eighth International Conference on Language Resources and Evaluation (LREC'12)

This paper describes POWLA, a generic formalism to represent linguistic corpora by means of RDF and OWL/DL. Unlike earlier approaches in this direction, POWLA is not tied to a specific selection of annotation layers, but rather, it is designed to support any kind of text-oriented annotation. POWLA inherits its generic character from the underlying data model PAULA (Dipper, 2005; Chiarcos et al., 2009) that is based on early sketches of the ISO TC37/SC4 Linguistic Annotation Framework (Ide and Romary, 2004). As opposed to existing standoff XML linearizations for such generic data models, it uses RDF as representation formalism and OWL/DL for validation. The paper discusses advantages of this approach, in particular with respect to interoperability and queriability, which are illustrated for the MASC corpus, an open multi-layer corpus of American English (Ide et al., 2008).

2011

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OWL/DL formalization of the MULTEXT-East morphosyntactic specifications
Christian Chiarcos | Tomaž Erjavec
Proceedings of the 5th Linguistic Annotation Workshop

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Evaluating Salience Metrics for the Context-Adequate Realization of Discourse Referents
Christian Chiarcos
Proceedings of the 13th European Workshop on Natural Language Generation

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Towards a Linguistic Linked Open Data cloud: The Open Linguistics Working Group
Christian Chiarcos | Sebastian Hellmann | Sebastian Nordhoff
Traitement Automatique des Langues, Volume 52, Numéro 3 : Ressources linguistiques libres [Free Language Resources]

2010

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Creating and Exploiting a Resource of Parallel Parses
Christian Chiarcos | Kerstin Eckart | Julia Ritz
Proceedings of the Fourth Linguistic Annotation Workshop

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Towards Robust Multi-Tool Tagging. An OWL/DL-Based Approach
Christian Chiarcos
Proceedings of the 48th Annual Meeting of the Association for Computational Linguistics

2009

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Building and Using a Richly Annotated Interlinear Diachronic Corpus: The Case of Old High German Tatian
Svetlana Petrova | Michael Solf | Julia Ritz | Christian Chiarcos | Amir Zeldes
Traitement Automatique des Langues, Volume 50, Numéro 2 : Langues anciennes [Ancient Languages]

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Information Structure in African Languages: Corpora and Tools
Christian Chiarcos | Ines Fiedler | Mira Grubic | Andreas Haida | Katharina Hartmann | Julia Ritz | Anne Schwarz | Amir Zeldes | Malte Zimmermann
Proceedings of the First Workshop on Language Technologies for African Languages

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By all these lovely tokens... Merging Conflicting Tokenizations
Christian Chiarcos | Julia Ritz | Manfred Stede
Proceedings of the Third Linguistic Annotation Workshop (LAW III)

2008

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A Flexible Framework for Integrating Annotations from Different Tools and Tag Sets
Christian Chiarcos | Stefanie Dipper | Michael Götze | Ulf Leser | Anke Lüdeling | Julia Ritz | Manfred Stede
Traitement Automatique des Langues, Volume 49, Numéro 2 : Plate-formes pour le traitement automatique des langues [Platforms for Natural Language Processing]

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Ontology-Based XQuery’ing of XML-Encoded Language Resources on Multiple Annotation Layers
Georg Rehm | Richard Eckart | Christian Chiarcos | Johannes Dellert
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

We present an approach for querying collections of heterogeneous linguistic corpora that are annotated on multiple layers using arbitrary XML-based markup languages. An OWL ontology provides a homogenising view on the conceptually different markup languages so that a common querying framework can be established using the method of ontology-based query expansion. In addition, we present a highly flexible web-based graphical interface that can be used to query corpora with regard to several different linguistic properties such as, for example, syntactic tree fragments. This interface can also be used for ontology-based querying of multiple corpora simultaneously.

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Ontology-Based Interface Specifications for a NLP Pipeline Architecture
Ekaterina Buyko | Christian Chiarcos | Antonio Pareja Lora
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

The high level of heterogeneity between linguistic annotations usually complicates the interoperability of processing modules within an NLP pipeline. In this paper, a framework for the interoperation of NLP components, based on a data-driven architecture, is presented. Here, ontologies of linguistic annotation are employed to provide a conceptual basis for the tagset-neutral processing of linguistic annotations. The framework proposed here is based on a set of structured OWL ontologies: a reference ontology, a set of annotation models which formalize different annotation schemes, and a declarative linking between these, specified separately. This modular architecture is particularly scalable and flexible as it allows for the integration of different reference ontologies of linguistic annotations in order to overcome the absence of a consensus for an ontology of linguistic terminology. Our proposal originates from three lines of research from different fields: research on annotation type systems in UIMA; the ontological architecture OLiA, originally developed for sustainable documentation and annotation-independent corpus browsing, and the ontologies of the OntoTag model, targeted towards the processing of linguistic annotations in Semantic Web applications. We describe how UIMA annotations can be backed up by ontological specifications of annotation schemes as in the OLiA model, and how these are linked to the OntoTag ontologies, which allow for further ontological processing.

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The Metadata-Database of a Next Generation Sustainability Web-Platform for Language Resources
Georg Rehm | Oliver Schonefeld | Andreas Witt | Timm Lehmberg | Christian Chiarcos | Hanan Bechara | Florian Eishold | Kilian Evang | Magdalena Leshtanska | Aleksandar Savkov | Matthias Stark
Proceedings of the Sixth International Conference on Language Resources and Evaluation (LREC'08)

Our goal is to provide a web-based platform for the long-term preservation and distribution of a heterogeneous collection of linguistic resources. We discuss the corpus preprocessing and normalisation phase that results in sets of multi-rooted trees. At the same time we transform the original metadata records, just like the corpora annotated using different annotation approaches and exhibiting different levels of granularity, into the all-encompassing and highly flexible format eTEI for which we present editing and parsing tools. We also discuss the architecture of the sustainability platform. Its primary components are an XML database that contains corpus and metadata files and an SQL database that contains user accounts and access control lists. A staging area, whose structure, contents, and consistency can be checked using tools, is used to make sure that new resources about to be imported into the platform have the correct structure.

2007

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PoCoS - Potsdam Coreference Scheme
Olga Krasavina | Christian Chiarcos
Proceedings of the Linguistic Annotation Workshop

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