Petri Leskinen

This paper shows how named entity extraction and networkanalysis can be used to examine biographies individually and in groupsto aid historians in biographical and prosopographical research. For this purpose a reference network of 13 100 biographies in the collections ofthe Biographical Centre of the Finnish Literature Society was created, based on links between the biographies as well as automatically extracted named entities found in the texts. The data was published in a SPARQL endpoint as a Linked Data knowledge graph on top of which network analytic tools were created and analysis were done showing the usefulness of the approach in Digital Humanities. The reference graph has been utilized for network analysis to examine egocentric networks of individual persons as well as networks among groups of people in prosopography. The data and tools presented are in use since autumn 2018 in the semantic portal BiographySampo that has had tens of thousands of users.

The Second World War (WW2) is arguably the most devastating catastrophe of human history, a topic of great interest to not only researchers but the general public. However, data about the Second World War is heterogeneous and distributed in various organizations and countries making it hard to utilize. In order to create aggregated global views of the war, a shared ontology and data infrastructure is needed to harmonize information in various data silos. This makes it possible to share data between publishers and application developers, to support data analysis in Digital Humanities research, and to develop data-driven intelligent applications. As a first step towards these goals, this article presents the WarSampo knowledge graph (KG), a shared semantic infrastructure, and a Linked Open Data (LOD) service for publishing data about WW2, with a focus on Finnish military history. The shared semantic infrastructure is based on the idea of representing war as a spatio-temporal sequence of events that soldiers, military units, and other actors participate in. The used metadata schema is an extension of CIDOC CRM, supplemented by various military historical domain ontologies. With an infrastructure containing shared ontologies, maintaining the interlinked data brings upon new challenges, as one change in an ontology can propagate across several datasets that use it. To support sustainability, a repeatable automatic data transformation and linking pipeline has been created for rebuilding the whole WarSampo KG from the individual source datasets. The WarSampo KG is hosted on a data service based on W3C Semantic Web standards and best practices, including content negotiation, SPARQL API, download, automatic documentation, and other services supporting the reuse of the data. The WarSampo KG, a part of the international LOD Cloud and totalling ca. 14 million triples, is in use in nine end-user application views of the WarSampo portal, which has had over 400 000 end users since its opening in 2015.

Semantic data integration from heterogeneous, distributed data silos enables Digital Humanities research and application development employing a larger, mutually enriched and interlinked knowledge graph. However, data integration is challenging, involving aligning the data models and reconciling the concepts and named entities, such as persons and places. This paper presents a record linkage process to reconcile person references in different military historical person registers with structured metadata. The information about persons is aggregated into a single knowledge graph. The process was applied to reconcile three person registers of the popular semantic portal WarSampo -- Finnish World War 2 on the Semantic Web . The registers contain detailed information about some 100,000 people and are individually maintained by domain experts. Thus, the integration process needs to be automatic and adaptable to changes in the registers. An evaluation of the record linkage results is promising and provides some insight into military person register reconciliation in general.

WarSampo Knowledge Graph includes harmonized data of different kinds concerning the Second World War in Finland, separated in different subgraphs representing events, actors, places, photographs, and other aspects and documentation of the war. The data covers the Winter War 1939-1940 against the Soviet attack, the Continuation War 1941-1944 where the occupied areas of the Winter War were temporarily regained, and the Lapland War 1944-1945, where the Finns pushed the German troops away from Lapland.

Biographies make a promising application case of Linked Data: they can be used, e.g., as a basis for Digital Humanities research in prosopography and as a key data and linking resource in semantic Cultural Heritage (CH) portals. In both use cases, a semantic data model for harmonizing and interlinking heterogeneous data from different sources is needed. This paper presents such a data model, Bio CRM, with the following key ideas: 1) The model is a domain specific extension of CIDOC CRM, making it applicable to not only biographical data but to other CH data, too. 2) The model makes a distinction between enduring unary roles of actors, their enduring binary relationships, and perduing events, where the participants can take different roles modeled as a role concept hierarchy. 3) The model can be used as a basis for semantic data validation and enrichment by reasoning. 4) The enriched data conforming to Bio CRM is targeted to be used by SPARQL queries in a flexible ways using a hierarchy of roles in which participants can be involved in events.

This paper shows how faceted search on biographical data can be utilized as a flexible basis for filtering target groups of people and, in particular, how generic data analysis and visualization tools can then be applied for solving prosopographical research questions based on the filtered data. This idea is demonstrated and evaluated in practice by presenting two application case studies: 1) linked data extracted from a printed registry of over 10 000 alumni (1867–1992) of the prominent Finnish high school Norssi, and 2) a knowledge graph extracted from 13 000 short biographies of significant Finnish people (from 3rd century to present times) in the National Biography of Finland. In both cases, the data is enriched by linking their entities with several other external datasets.

Biografiasampo-järjestelmä käynnistää uuden aikakauden elämäkertakokoelmien julkaisemisessa ja käyttämisessä verkossa. Järjestelmän ydinaineistona on Kansallisbiografia ja muut Suomalaisen Kirjallisuuden Seuran (SKS) ja tieteellisten seurojen toimittamat pienoiselämäkerrat, yhteensä 13 100 elämäntarinaa, joita on kirjoittanut 900 suomalaista tutkijaa. Biografiasammon innovaationa on luoda kieliteknologian, tekoälyn ja semanttisen webin teknologioiden avulla elämäkertojen teksteistä ja niihin eri lähteissä liittyvistä tiedoista tietämysverkko (knowledge graph) ja kansallinen tietoinfrastruktuuri, joka koostuu miljoonista tietojen välisistä yhteyksistä. Tietämysverkko on julkaistu linkitetyn datan palvelussa, jonka varaan on toteutettu seitsemästä sovellusnäkymästä koostuva älykäs, kaikille avoin ja maksuton verkkopalvelu biografiasampo.fi kansalaisten ja digitaalisten ihmistieteiden tutkijoiden käytettäväksi.

This paper presents the vision of publishing and utilizing textual biographies as Linked (Open) Data on the Semantic Web. As a case study, we publish the live stories of the National Biography of Finland, created by the Finnish Literature Society, as semantic, i.e., machine “understandable” metadata in a SPARQL endpoint using the Linked Data Finland (LDF.fi) service. On top of the data service various Digital Humanities applications are built. The applications include searching and studying individual personal histories as well as historical research of groups of persons using methods of prosopography. The biographical data is enriched by extracting events from unstructured and semi-structured texts, and by linking entities internally and to external data sources. A faceted semantic search engine is provided for filtering groups of people from the data for prosopographical research. An extension of the event-based CIDOC CRM ontology is used as the underlying data model, where lives are seen as chains of interlinked events populated from the data of the biographies and additional data sources, such as museum collections, library databases, and archives.

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.

This paper describes the ontology model and published datasets of a digitized biographical person register. The applied ontology model is designed to represent people via their enduring roles and perduring lifetime events. The model is designed to support 1) prosopographical Digital Humanities research, 2) linking to resources in semantic Cultural Heritage portals, and 3) semantic data validation and enrichment by using SPARQL queries. The linked data approach enables to enrich a person s biography by interlinking it with space and time related biographical events, persons relating by social contacts or family relations, historical events, and personal achievements.

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.

This paper presents an application for studying the death records of WW2 casualties from a prosopograhical perspective, provided by the various local military cemeteries where the dead were buried. The idea is to provide the end user with a global visual map view on the places in which the casualties were buried as well as with a local historical perspective on what happened to the casualties that lay within a particular cemetery of a village or town. Plenty of data exists about the Second World War (WW2), but the data is typically archived in unconnected, isolated silos in different organizations. This makes it difficult to track down, visualize, and study information that is contained within multiple distinct datasets. In our work, this problem is solved using aggregated Linked Open Data provided by the WarSampo Data Service and SPARQL endpoint.

The article overviews the system WarSampo – Finnish World War 2 on the Semantic Web, the winner of the LODLAM Challenge 2017 Open Data Prize on June 29 in Venice, Italy.

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 WarSampo and Semantic Finlex 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.

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.

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 rich 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.

Toimijaontologia mallintaa henkilöitä ja henkilöryhmiä linkitetyssä avoimessa datassa. Toimijaontologiamallin tarkoitus on mahdollistaa eri lähteiden aineistojen kokoaminen yhteen ja sen julkaisu yhdenmukaisessa formaatissa, jotta tietoa voidaan hyödyntää niin digitaalisten ihmistieteiden tutkimuksessa kuin tarjoamalla käyttöliittymiä aineiston selaamiseen visuaalisessa muodossa. Laadittu ontologia noudattaa toimija–tapahtuma-mallia. Siinä toimija mallinnetaan häneen liittyvien elämäkerrallisten tapahtumien summana. Ratkaisujen perustana käytettiin CIDOC CRM -standardia, millä haluttiin taata mallin helppo laajennettavuus sekä noudattaa kulttuurihistorialliselle datalle yhdenmukaista julkaisukäytäntöä. Työ on tehty osana laajempaa Sotasampo-projektia, johon kerättiin kattava tietokanta toisen maailmansodan aikaista aineistoa Suomen osalta. Oma osuuteni tässä työssä oli toimijaontologiamallin laatiminen sekä sen populointi sotilashenkilöillä ja -osastoilla. Aineisto on julkaistu avoimena datana (http://www.ldf.fi/dataset/warsa) ja on selattavissa Sotasampo-portaalissa (http://www.sotasampo.fi).

Data about wars is typically heterogeneous, distributed in the data silos of the fighting parties, multilingual, and often controversial depending on the political point of view. It is therefore hard for the historians to get a global picture of what has actually happened, to whom, where, when, and how. We argue that Semantic Web and Linked Data technologies are a very promising approach for modeling, harmonizing, and aggregating data about war history. Our goal is to make it possible, for both historians and laymen, to study history in a contextualized way where linked datasets enrich each other. The paper presents the in-use WarSampo 1 system, where massive collections of heterogeneous data about the (Finnish) history of the Second World War are harmonized using an event-based approach, and provided as a Linked Open Data service for applications to use. As a use case, a semantic portal WarSampo providing six different perspectives to the war based on events is presented.

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.

This paper presents the WarSampo system for publishing collections of heterogeneous, distributed data about the Second World War on the Semantic Web. WarSampo is based on harmonizing massive datasets using event-based modeling, which makes it possible to enrich datasets semantically with each others’ contents. WarSampo has two components: First, a Linked Open Data (LOD) service WarSampo Data for Digital Humanities (DH) research and for creating applications related to war history. Second, a semanticWarSampo Portal has been created to test and demonstrate the usability of the data service. The WarSampo Portal allows both historians and laymen to study war history and destinies of their family members in the war from different interlinked perspectives. Published in November 2015, theWarSampo Portal had some 20,000 distinct visitors during the first three days, showing that the public has a great interest in this kind of applications.

This paper initiates and fosters work on publishing Linked Open Data about the Second World War. It is argued that the heterogeneous, distributed data about the international world war history makes a promising use case for semantic technologies. We hope that by making war data openly available we can learn from the past and promote peace.