Petri Leskinen

Linked Death—Representing, Publishing, and Using Second World War Death Records as Linked Open Data

War history of the Second World War (WW2), humankind’s largest disaster, is of great interest to both laymen and researchers. Most of us have ancestors and relatives who participated in the war, and in the worst case got killed. Researchers are eager to find out what actually happened then, and even more importantly why, so that future wars could perhaps be prevented. The darkest data of war history are casualty records—from such data we could perhaps learn most about the war. This paper presents a model and system for representing death records as linked data, so that (1) citizens could find out more easily what happened to their relatives during WW2 and (2) digital humanities (DH) researchers could (re)use the data easily for research.

Reassembling and enriching the life stories in printed biographical registers: Norssi high school alumni on the semantic web

This paper presents the idea to enrich printed biographical person registers with linked data related to events that took place after the register was published. By transforming printed historical documents into structured data, semantic search to written texts can be provided for the reader. Even more importantly, life stories of historical persons can be extended based on data linking by extracting semantic structures from printed texts, and by combining this data with external datasets and data services. Such linking provides an enriched context for prosopographical research on people in the register, as well as an enhanced reading experience for anyone interested in reading the biographies. As a concrete case study, a register 1867–1992 of over 10 000 alumni of the prominent Finnish high school “Norssi” was transformed into RDF, was enriched by data linking, was published as a linked data service, and is provided to end users via a faceted search engine and browser for studying lives of historical persons and for prosopographical research.

Named Entity Linking in a Complex Domain: Case Second World War History

This paper discusses the challenges of applying named entity linking in a rich, complex domain – specifically, the linking of (1) military units, (2) places and (3) people in the context of interlinked Second World War data. Multiple sub-scenarios are discussed in detail through concrete evaluations, analyzing the problems faced, and the solutions developed. A key contribution of this work is to highlight the heterogeneity of problems and approaches needed even inside a single domain, depending on both the source data as well as the target authority.

AATOS – A Configurable Tool for Automatic Annotation

This paper presents an automatic annotation tool AATOS for providing documents with semantic annotations. The tool links entities found from the texts to ontologies defined by the user. The application is highly configurable and can be used with different natural language Finnish texts. The application was developed as a part of the WarSampo (http://seco.cs.aalto.fi/projects/sotasampo/en/) and Semantic Finlex (http://seco.cs.aalto.fi/projects/lawlod/en/) projects and tested using Kansa Taisteli magazine articles and consolidated Finnish legislation of Semantic Finlex. The quality of the automatic annotation was evaluated by measuring precision and recall against existing manual annotations. The results showed that the quality of the input text, as well as the selection and configuration of the ontologies impacted the results.

Using Linked Data for Prosopographical Research of Historical Persons: Case U.S. Congress Legislators

This paper shows how biographical registries can be represented as Linked Data, enriched by data linking to related data sources, and used in Digital Humanities. As a use case, a database of 11 987 historical U.S. Congress Legislators in 1789–2018 was transformed into a knowledge graph. The data was published as a Linked Data service, including a SPARQL endpoint, on top of which tools for biographical and prosopographical research are implemented. A faceted browser named U.S. Congress Prosopographer with visualization tools for knowledge discovery is presented to provide new insights in political history.

Using Biographical Texts as Linked Data for Prosopographical Research and Applications

This paper argues that representing texts as semantic Linked Data provides a useful basis for analyzing their contents in Digital Humanities research and for Cultural Heritage application development. The idea is to transform Cultural Heritage texts into a knowledge graph and a Linked Data service that can be used flexibly in different applications via a SPARQL endpoint. The argument is discussed and evaluated in the context of biographical and prosopographical research and a case study where over 13 000 life stories form biographical collections of Biographical Centre of the Finnish Literature Society were transformed into RDF, enriched by data linking, and published in a SPARQL endpoint. Tools for biography and prosopography, data clustering, network analysis, and linguistic analysis were created with promising first results.

Modeling and Using an Actor Ontology of Second World War Military Units and Personnel

This paper presents a model for representing historical military personnel and army units, based on large datasets about World War II in Finland. The model is in use in WarSampo data service and semantic portal, which has had tens of thousands of distinct visitors. A key challenge is how to represent ontological changes, since the ranks and units of military personnel, as well as the names and structures of army units change rapidly in wars. This leads to serious problems in both search as well as data linking due to ambiguity and homonymy of names. In our solution, actors are represented in terms of the events they participated in, which facilitates disambiguation of personnel and units in different spatio-temporal contexts. The linked data in the WarSampo Linked Open Data cloud and service has ca. 9 million triples, including actor datasets of ca. 100 000 soldiers and ca. 16 100 army units. To test the model in practice, an application for semantic search and recommending based on data linking was created, where the spatio-temporal life stories of individual soldiers can be reassembled dynamically by linking data from different datasets. An evaluation is presented showing promising results in terms of linking precision.