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Eetu Mäkelä

Researcher, D.Sc.
Aalto University, University of Helsinki, University of Oxford
phone: +358 (0)50 3070509
email: eetu.makela@aalto.fi
other identities

Academic CV

Current area of scientific interest: supporting humanities research based on rich unstructured and structured data

Emerging digital collections of both unstructured (e.g. text corpora from magazines, letters or classical texts), as well as structured (e.g. letter, travel or occupation data on persons of interest) data provide humanities researchers with a wealth of material to base research on. However, many problems still arise from the particular natures of humanities research and humanities data.

First, humanities research often necessitates interpretative inference to a much larger degree than other sciences - that is, the primary sources and databases often do not contain directly the information of interest to the scholar, but this must be deduced and extracted to produce the final data conclusions are based on. For example, in studying the social circles of Enlightenment luminaries, researchers at Stanford took a database containing e.g. correspondence and occupation information on them, but then mapped that information into more general religious, professional and social spheres of influence.

In current processes, this inferred data is often lost. Yet, if such interpretations could be opened for reuse through publishing them as data, a massive potential for speeding up humanities research could be realized. Doing this however requires tool support, including stringent tracking for the grounding of such inference.

A second problem arises from the fact that traditional computational data analysis methods are ill-equipped to deal with the messiness, spottiness and uncertainty of most humanities datasets. For example, tools for statistical analysis of text currently often cannot account for the variability of spelling in historical datasets, while also structured datasets suffer from inconsistencies in coding (e.g. referring to the same places or people by different names or just suffering from typographical errors and variation).

Current systems also do not adequately highlight gaps in the data, such as how many books in a database don’t have a place of publication attached, which may lead to drawing incorrect inferences from reports and visualizations based on that data. Neither can current systems account for, or highlight the inherent uncertainty associated with most humanities data, where e.g. different sources can give different birth and death dates to a person, or where the location a letter was sent from has been encoded in a database using one of three distinct levels of certainty.

For more information, see the VISCERA project.

Selected presentations

in English

in Finnish

Selected software

  • Recon, a multipurpose tool for semi-automatic matching of records against a SPARQL endpoint
  • SeCo Lexical Analysis Service, a web service for lexical analysis
  • CORE, a contextual reader based on Linked Data
  • ARPA, a web service for configurable automated entity recognition from text against a SPARQL endpoint
  • VISU, a visual SPARQL query tool
  • Aether, a tool for exploring statistics of Linked Data datasets
  • Snapper, an editor for the Turtle serialization of RDF
  • a fork of the Finnish morphological analyzer Omorfi, with better handling for early modern Finnish, segmentation and dehyphenation
  • seco-hfst, a thread-safe Java version of the Helsinki Finite State Transducer Lookup

Publications

2016

Tuula Pääkkönen, Jukka Kervinen, Asko Nivala, Kimmo Kettunen and Eetu Mäkelä: Exporting Digitized Historical Newspaper Contents for Offline Use. D-Lib, vol. 22, no. 7/8, 2016. bib link
Digital collections of the National Library of Finland (NLF) contain over 10 million pages of historical newspapers, journals and some technical ephemera. The material ranges from the early Finnish newspapers from 1771 until the present day. The material up to 1910 can be viewed in the public web service, where as anything later is available at the six legal deposit libraries in Finland. A recent user study noticed that a different type of researcher use is one of the key uses of the collection. National Library of Finland has gotten several requests to provide the content of the digital collections as one offline bundle, where all the needed content is included. For this purpose we introduced a new format, which contains three different information sets: the full metadata of a publication page, the actual page content as ALTO XML, and the raw text content. We consider these formats most useful to be provided as raw data for the researchers. In this paper we will describe how the export format was created, how other parties have packaged the same data and what the benefits are of the current approach. We shall also briefly discuss word level quality of the content and show a real research scenario for the data.
Eetu Mäkelä, Juha Törnroos, Thea Lindquist and Eero Hyvönen: WW1LOD - An application of CIDOC-CRM to World War 1 Linked Data. International Journal on Digital Libraries, 2016. In press. bib pdf
The CIDOC-CRM standard indicates that common events, actors, places and timeframes are important in linking together cultural material, and provides a framework for describing them. However, merely describing entities in this way in two datasets does not yet interlink them. To do that, the identities of instances still need to be either reconciled, or be based on a shared vocabulary. The WW1LOD dataset presented in this paper was created to facilitate both of these approaches for collections dealing with the First World War. For this purpose, the dataset includes events, places, agents, times, keywords, and themes related to the war, based on over ten different authoritative data sources from providers such as the Imperial War Museum. The content is harmonized into RDF, and published as a Linked Open Data service. While generally basing on CIDOC-CRM, some modeling choices used also deviate from it where our experience dictated such. In the article, these deviations are discussed in the hope that they may serve as examples where CIDOC-CRM itself may warrant further examination. As a demonstration of use, the dataset and online service have been used to create a contextual reader application that is able link together and pull in information related to WW1 from e.g. 1914–1918 Online, Wikipedia, WW1 Discovery, Europeana and the Digital Public Library of America.
Eetu Mäkelä, Thea Lindquist and Eero Hyvönen: CORE - A Contextual Reader based on Linked Data. Proceedings of Digital Humanities 2016, long papers, pp. 267-269, Kraków, Poland, July, 2016. bib pdf link
CORE is a contextual reader application intended to improve user close reading experience, particularly with regard to material in an unfamiliar domain. CORE works by utilizing Linked Data reference vocabularies and datasets to identify entities in any PDF file or web page. For each discovered entity, pertinent information such as short descriptions, pictures, or maps are sourced and presented on a mouse-over, to allow users to familiarize themselves with any unfamiliar concepts, places, etc in the texts they are reading. If further information is needed, an entity can be clicked to open a full context pane, which supports deeper contextualization (also visually, e.g. by displaying interactive timelines or maps). Here, CORE also facilitates serendipitous discovery of further related knowledge, by being able to bring in and suggest related resources from various repositories. Clicking on any such resource loads it into the contextual reader for endless further browsing.
Eetu Mäkelä, Tanja Säily and Terttu Nevalainen: Khepri - a Modular View-Based Tool for Exploring (Historical Sociolinguistic) Data. Proceedings of Digital Humanities 2016, long papers, pp. 269-272, Kraków, Poland, July, 2016. bib pdf link
Digital humanities needs tools that better support the core processes of humanistic inquiry. This includes support for handling uncertainty and incompleteness in the data, for interactive exploration, and for fluidly moving between close and distant reading. The Khepri tool presented here is part of a user-centered project to develop a modular set of components that take these requirements into account, and can be connected and configured to respond to the needs of a particular humanities task and data. Here, the configuration presented is one for the field of historical sociolinguistics, developed in collaboration between computer scientists and sociolinguistic researchers.
Eero Hyvönen, Erkki Heino, Petri Leskinen, Esko Ikkala, Mikko Koho, Minna Tamper, Jouni Tuominen and Eetu Mäkelä: Publishing Second World War History as Linked Data Events on the Semantic Web. Proceedings of Digital Humanities 2016, short papers, pp. 571-573, Kraków, Poland, July, 2016. bib pdf link
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.
Mikko Koho, Eero Hyvönen, Erkki Heino, Jouni Tuominen, Petri Leskinen and Eetu Mäkelä: Linked Death - Representing, Publishing, and Using Second World War Death Records as Linked Open Data. The Semantic Web: ESWC 2016 Satellite Events (Harald Sack, Giuseppe Rizzo, Nadine Steinmetz, Dunja Mladenić, Sören Auer and Christoph Lange (eds.)), Springer-Verlag, June, 2016. bib pdf
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.
Mikko Koho, Eero Hyvönen, Erkki Heino, Jouni Tuominen, Petri Leskinen and Eetu Mäkelä: Linked Death - Representing, Publishing, and Using Second World War Death Records as Linked Open Data. Proceedings of the 1st Workshop on Humanities in the Semantic Web (WHiSe), CEUR Workshop Proceedings, Heraklion, Crete, Greece, May, 2016. Vol 1608. bib pdf link
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.
Eero Hyvönen, Erkki Heino, Petri Leskinen, Esko Ikkala, Mikko Koho, Minna Tamper, Jouni Tuominen and Eetu Mäkelä: WarSampo Data Service and Semantic Portal for Publishing Linked Open Data about the Second World War History. The Semantic Web – Latest Advances and New Domains (ESWC 2016) (Harald Sack, Eva Blomqvist, Mathieu d Aquin, Chiara Ghidini, Simone Paolo Ponzetto and Christoph Lange (eds.)), Springer-Verlag, May, 2016. bib pdf
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.

2015

Eero Hyvönen, Jouni Tuominen, Esko Ikkala and Eetu Mäkelä: Ontology Services Based on Crowdsourcing: Case National Gazetteer of Historical Places. Proceedings of the ISWC 2015 Posters & Demonstrations Track, CEUR-WS Proceedings, Bethlehem, PA, USA, October, 2015. Vol 1486. bib pdf link
This paper introduces the idea of applying crowdsourcing to evolving ontology services; the goal is to facilitate collaborative maintenance of ontologies in real time as a side effect of annotating contents in legacy cataloging systems. The idea is being implemented in the use case of creating and managing a national level gazetteer of historical places in Finland.
Eero Hyvönen, Jouni Tuominen, Eetu Mäkelä, Jérémie Dutruit, Kasper Apajalahti, Erkki Heino, Petri Leskinen and Esko Ikkala: Second World War on the Semantic Web: The WarSampo Project and Semantic Portal. Proceedings of the ISWC 2015 Posters & Demonstrations Track, CEUR-WS Proceedings, Bethlehem, PA, USA, October, 2015. Vol 1486. bib pdf link
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.

2014

Esko Ikkala, Eetu Mäkelä and Eero Hyvönen: TourRDF: Representing, Enriching, and Publishing Curated Tours Based on Linked Data. 19th International Conference of Knowledge Engineering and Management (EKAW 2014), Demo and Poster Papers, November, 2014. bib pdf
Current mobile tourist guide systems are developed and used in separate data silos: each system and vendor tends to use its own proprietary, closed formats for representing tours and point of interest (POI) content. As a result, tour data cannot be enriched from other providers’ tour and POI repositories, or from other external data sources — even when such data were publicly available by, e.g., cities willing to promote tourism. This paper argues, that an open shared RDF-based tour vocabulary is needed to address these problems, and introduces such a model, TourRDF, extending the earlier TourML schema into the era of Linked Data. As a test and an evaluation of the approach, a case study based on data about the Unesco World Heritage site Suomenlinna fortress is presented.
Eero Hyvönen, Miika Alonen, Esko Ikkala and Eetu Mäkelä: Life Stories as Event-based Linked Data: Case Semantic National Biography. Proceeedings of ISWC 2014 Posters & Demonstrations Track, CEUR Workshop Proceedings, October, 2014. bib pdf link
This paper argues, by presenting a case study and a demonstration on the web, that biographies make a promising application case of Linked Data: the reading experience can be enhanced by enriching the biographies with additional life time events, by proving the user with a spatio-temporal context for reading, and by linking the text to additional contents in related datasets.
Eetu Mäkelä: Aether - Generating and Viewing Extended VoID Statistical Descriptions of RDF Datasets. Proceedings of the ESWC 2014 demonstration track, Springer-Verlag, May, 2014. bib pdf
This paper presents the Aether web application for generating, viewing and comparing extended VoID statistical descriptions of RDF datasets. The tool is useful for example in getting to know a newly encountered dataset, in comparing datasets between versions and in detecting outliers and errors. Examples are given on how the tool has been used to shed light on multiple important datasets.
Eetu Mäkelä: Combining a REST Lexical Analysis Web Service with SPARQL for Mashup Semantic Annotation from Text. Proceedings of the ESWC 2014 demonstration track, Springer-Verlag, May, 2014. bib pdf
Current automatic annotation systems are often monolithic, holding internal copies of both machine-learned annotation models and the reference vocabularies they use. This is problematic particularly for frequently changing references such as person and place registries, as the information in the copy quickly grows stale. In this paper, arguments and experiments are presented on the notion that sufficient accuracy and recall can both be obtained simply by combining a sufficiently capable lexical analysis web service with querying a primary SPARQL store, even in the case of often problematic highly inflected languages.
Eero Hyvönen, Jouni Tuominen, Miika Alonen and Eetu Mäkelä: Linked Data Finland: A 7-star Model and Platform for Publishing and Re-using Linked Datasets. Proceedings of ESWC 2014 Demo and Poster Papers, Springer-Verlag, May, 2014. bib pdf
The idea of Linked Data is to aggregate, harmonize, integrate, enrich, and publish data for re-use on the Web in a cost-efficient way using Semantic Web technologies. We concern two major hindrances for re-using Linked Data: It is often difficult for a re-user to 1) understand the characteristics of the dataset and 2) evaluate the quality the data for the intended purpose. This paper introduces the “Linked Data Finland” platform LDF.fi addressing these issues. We extend the famous 5-star model of Tim Berners-Lee, with the sixth star for providing the dataset with a schema that explains the dataset, and the seventh star for validating the data against the schema. LDF.fi also automates data publishing and provides data curation tools. The first prototype of the platform is available on the web as a service, hosting tens of datasets and supporting several applications.
Eetu Mäkelä and Eero Hyvönen: SPARQL SAHA, a Configurable Linked Data Editor and Browser as a Service. Proceedings of the ESWC 2014 demonstration track, Springer-Verlag, May, 2014. bib pdf
SPARQL SAHA is a linked data editor and browser that can be used as a service, targeting any available SPARQL endpoint. Besides being available as a web service, the primary differentiating features of the tool are its configurability to match the underlying data, and the fact that the usability of its user interface has been verified by dozens of non-experts using the tool in multiple multi-year projects.

2013

Eetu Mäkelä, Kaisa Hypén and Eero Hyvönen: Fiction Literature as Linked Open Data - the BookSampo Dataset. Semantic Web – Interoperability, Usability, Applicability, 2013. bib pdf
The BookSampo dataset provides information as linked data on fiction literature published in Finland going back to the 15th century, along with rich descriptions of both their content and context. The dataset contains data on nearly 400,000 subjects, including literary works, authors, book covers, reviews, awards, images, and movies, over 3 million triples in total. The data has been applied as the basis of the BookSampo portal in public use in Finland, and is aligned with the cross-domain cultural heritage contents and ontologies of CultureSampo, another in-use semantic portal. The data has been used to answer complex questions, such as what topics should one write about, if one wants to get a literary award (based on statistics). The metadata was transformed into RDF from legacy library databases, then enriched manually by dozens of librarians in a Web 2.0 fashion in Finnish public libraries, and is constantly updated at a rate of some new 90,000 triples monthly.
Tuukka Ruotsalo, Krister Haav, Antony Stoyanov, Sylvain Rochee, Elena Fanid, Romina Deliaic, Eetu Mäkelä, Tomi Kauppinen and Eero Hyvönen: SMARTMUSEUM: A Mobile Recommender System for the Web of Data. Journal of Web Semantics, vol. 20, Elsevier, 2013. bib link
Semantic and context knowledge have been envisioned as an appropriate solution for addressing the content heterogeneity and information overload in mobile Web information access, but few have explored their full potential inmobile scenarios, where information objects refer to their physical counterparts, and retrieval is context-aware and personalized for users. We present SMARTMUSEUM, a mobile ubiquitous recommender system for the Web of Data, and its application to information needs of tourists in context-aware, on-site access to cultural heritage. The SMARTMUSEUM system utilizes Semantic Web languages as the form of data representation. Ontologies are used to bridge the semantic gap between heterogeneous content descriptions, sensor inputs, and user profiles. The system makes use of an information retrieval framework where in context data and search result clustering are used in recommendation of suitable content for mobileusers. Results from laboratory experiments demonstrate that ontology-based reasoning, query expansion, search result clustering, and context knowledge lead to significant improvement in recommendation performance. The results from field trials show that the usability of the system meets users’ expectations in real-world use. The results indicate that semantic content representation and retrieval can significantly improve the performance of mobile recommender systems in knowledge-rich domains.
Thea Lindquist, Michael Dulock, Juha Törnroos, Eero Hyvönen and Eetu Mäkelä: Using Linked Open Data to Enhance Subject Access in Online Primary Sources. Cataloging & Classifying Quarterly, vol. 51, no. 8, Francis & Taylor, 2013. bib link
Using online primary sources is both rewarding and challenging for users. Improving subject access is essential as these sources become increasingly important in educational curricula. A user needs assessment with humanities users showed improving findability and context for historical subjects were major needs. Linked Data can help by linking related concepts in the sources using specialized vocabularies, enriching them with outside resources, and enabling semantic services that empower users. This article discusses a project to enhance subject access in an online World War I collection by deep linking historical data on the civilian experience in occupied Belgium and France.
Eero Hyvönen, Miika Alonen, Jouni Tuominen, and Eetu Mäkelä: Linked Data Finland: Towards a 7-star Service Platform for Linked Datasets. The First Annual KnowEscape Conference - KnowEscape 2013, Espoo, Finland, November, 2013. bib pdf
The idea of opening data on the Web as Linked Data (LD) is widely adopted in areas such as public government, science, libraries, and cultural heritage. The key idea is to harmonize, integrate, enrich, and re-use existing data repositories in a cost-efficient way via standard APIs in novel applications. This paper concerns two major hindrances for re-using LD: It is often difficult for a re-user to understand the 1) characteristics of the dataset and 2) evaluate the quality of the data for her intended purpose. This paper introduces the “Linked Data Finland” publishing platform LDF.fi addressing these issues. In order to enhance and promote reusability, we propose extending the famous 5-star model of Tim Berners-Lee into a 7-star model: The sixth star requires that the dataset is defined and explained in terms of explicit schemas. Explicit schemas make it possible to explain the re-user the intended characteristics of the data by, e.g., documentation about the schemas, and how the schemas (vocabularies) are actually used in the given dataset. The seventh star is given, if the data has also been validated w.r.t. the schema specifications. The results of the validation may be a human readable document and/or a machine readable reprentation regarding the quality issues found in the data. This paper reports about work in progress, but the first prototype of the platform is already operational on the web as a service http://ldf.fi.

2012

Kim Viljanen, Jouni Tuominen, Eetu Mäkelä and Eero Hyvönen: Normalized Access to Ontology Repositories. Proceedings of the Sixth International Conference on Semantic Computing (IEEE ICSC 2012), IEEE Press, Palermo, Italy, September, 2012. bib pdf
Ontology repositories, such as NCBO Bioportal, ONKI and Cupboard, help finding and using ontologies on the Semantic Web. However, currently each ontology repository constitutes a separate island with its own user interface, APIs, users, ontology languages and set of ontologies. Because there is not a universal way to access all ontology repositories, doing global search, browsing, and inference over all available ontology repositories turns out to be technically difficult and is generally not done. Ontologies are not reused as much as they could and hence the full potential of ontologies is not achieved. To address the problem, we propose the Normalized Ontology Repository (NOR) approach to make the ontology repositories universally accessible while maintaining their unique functionalities and strengths. The SKOS language is used as the lowest common denominator for presenting the ontologies. In addition, a simple API for searching and accessing the ontologies is defined. As a proof-of-concept evaluation, we present three case implementations to demonstrate the NOR approach: 1) the distributed architecture of the ONKI repository, 2) the metasearch for ONKI and NCBO Bioportal, and 3) publishing informal ontological concept collections as NOR end-points, demonstrated with the semantic portal CultureSampo and the metadata editor SAHA.
Eetu Mäkelä, Kaisa Hypén and Eero Hyvönen: Improving Fiction Literature Access by Linked Open Data -Based Collaborative Knowledge Storage - the BookSampo Project. World Library and Information Congress: 78th IFLA General Conference and Assembly, Helsinki, IFLA, http://conference.ifla.org/ifla78, August, 2012. bib pdf
BookSampo is a joint project between the Finnish public libraries and semantic web researchers, to improve fiction literature search and recommendation. In the project, dozens of librarians around Finland have used a collaborative web-based metadata editor to input diverse knowledge about fiction literature into a shared database. Particularly, the project has sought to improve access by indexing not only bibliographical information about the books, but focusing on the content and context of the works. In order to do this, the database employs advanced techniques such as functional, content-centered indexing, ontological vocabularies and the networked data model of linked open data. To demonstrate the functionality this makes possible, the fiction literature portal http://www.kirjasampo.fi/ was created. This portal uses the knowledge created in the project to offer advanced semantic search and recommendation based on the database created. In addition, web services exposing direct access to the data have been used for example in culture hack events to answer more complex questions, such as where in Finland are the most crimes committed in fiction literature.
Thea Lindquist, Eero Hyvönen, Juha Törnroos, Eetu Mäkelä: Leveraging linked data to enhance subject access - A case study of the University of Colorado Boulder s World War I collection online. World Library and Information Congress: 78th IFLA General Conference and Assembly, Helsinki, IFLA, http://conference.ifla.org/ifla78, August, 2012. bib link
Academic users often find work with online primary sources both rewarding and challenging. Improving subject access in these sources is essential as digital collections propagate and work with primary sources becomes increasingly important in humanities curricula. A user needs assessment was conducted with humanities users at the University of Colorado Boulder to facilitate engagement with these sources. Two of the major user needs identified were improving findability and context, particularly for historical subjects. Linked Data can help meet these needs by linking related concepts in the sources using a specialized vocabulary, enriching them with outside resources, and enabling semantically rich services that empower users. This paper discusses a project the authors undertook to enhance subject access in CU’s WWI Collection Online by deep linking historical data on the civilian experience in occupied Belgium. This work is intended to lead to a richer understanding of forces shaping the WWI period.
Eero Hyvönen, Thea Lindquist, Juha Törnroos and Eetu Mäkelä: History on the Semantic Web as Linked Data - An Event Gazetteer and Timeline for World War I. Proceedings of CIDOC 2012 - Enriching Cultural Heritage, Helsinki, Finland, CIDOC, http://www.cidoc2012.fi/en/cidoc2012/programme, June, 2012. bib pdf
Events are an essential component of cultural heritage (CH) Linked Data (LD): they link actors, places, times, objects, and other events into larger narrative structures, providing a rich basis for semantic searching, recommending, analysis, and visualization of CH data. This paper argues that shared vocabularies (gazetteers, ontologies) of events, such as the “Battle of Normandy” or “Crucifixion of Jesus”, are necessary to facilitate the aggregation and linking of heterogeneous content from various collections. For example, biographies, histories, photos, and paintings often reference or depict events. A set of general requirements for an event gazetteer is presented, based on the needs of publishing, aggregating, and reusing cultural heritage content as Linked Data. After this, a metadata model addressing the presented requirements for representing historical events is outlined. The model is being applied in a case study aimed at developing an event ontology for World War I (WWI). Our goals from an end-user perspective are twofold: 1) Facilitate event-based cataloging for curators in memory organizations; 2) Utilize semantic event descriptions and narrative event structures in end-user applications for searching and linking documents and other content about WWI, and for structuring and visualizing them.
Eero Hyvönen, Aleksi Lindblad and Eetu Mäkelä: TravelSampo System for Creating Mobile Audio Guide Tours Enriched with Linked Data. Proceedings of CIDOC 2012 - Enriching Cultural Heritage, Helsinki, Finland, CIDOC, http://www.cidoc2012.fi/en/cidoc2012/programme, June, 2012. bib pdf
TravelSampo [1] is a prototype system, by which museums are able to create interactively audio guide tours inside museums and outside in the open air. The system includes a web-based editor by which a curator can describe objects in an exhibition, or in the open air, using a set of shared ontologies published in the National Ontology Service ONKI (http://onki.fi/), and upload related audio descriptions, text, and images. Each exhibit object is given an identifier and a geo-location. When the end-user is near the object, either in a museum or in the open air, information related to the object can be given to her based on the object identifier or GPS location. A major novelty of TravelSampo lies in its ability to associate the object metadata automatically with millions of semantically related pieces of information available though the Linked Data cloud (http://linkedata.org/) and the CultureSampo system (http://www.kulttuurisampo.fi/). For example, a painting can be linked, based on the underlying ontologies and metadata, with the biography of the painter in Wikipedia or in the National Biography, with other paintings of the artist in the collections of other museums, with photos and books about the artist, and so on. This gives the end-user a richer experience than is possible with traditional audio guide systems. For the museums, TravelSampo offers a cost-efficient and dynamic way of creating information rich audio guide programs, and re-using and linking each others collections through linked data, leading to a win-win situation. The paper presents and discusses the underlying ideas of TravelSampo and our experiences in developing the systems especially from the content publishers’, i.e. the museums’ viewpoint. [1] E. Mäkelä, J. Väätäinen, R. Alitalo, O. Suominen, E. Hyvönen: Discovering Places of Interest through Direct and Indirect Associations in Heterogeneous Sources - The TravelSampo System. Terra Cognita 2011: Foundations, Technologies and Applications of the Geospatial Web, CEUR Workshop Proceedings, Vol-798, 2011. http://ceur-ws.org/Vol-798/proceedings.pdf
Eetu Mäkelä, Eero Hyvönen and Tuukka Ruotsalo: How to deal with massively heterogeneous cultural heritage data – lessons learned in CultureSampo. Semantic Web – Interoperability, Usability, Applicability, vol. 3, no. 1, January, 2012. bib pdf link
This paper presents the CultureSampo system for publishing heterogeneous linked data as a service. Discussed are the problems of converting legacy data into linked data, as well as the challenge of making the massively heterogeneous yet interlinked cultural heritage content interoperable on a semantic level. Novel user interface concepts for then utilizing the content are also presented. In the approach described, the data is published not only for human use, but also as intelligent services for other computer systems that can then provide interfaces of their own for the linked data. As a concrete use case of using CultureSampo as a service, the BookSampo system for publishing Finnish fiction literature on the semantic web is presented.

2011

Eetu Mäkelä, Kaisa Hypén and Eero Hyvönen: BookSampo--Lessons Learned in Creating a Semantic Portal for Fiction Literature. Proceedings of ISWC-2011, Bonn, Germany, Springer-Verlag, 2011. bib pdf
BookSampo is a semantic portal in use, covering metadata about practically all Finnish fiction literature of Finnish public libraries on a work level. The system introduces a variety of semantic web novelties deployed into practise: The underlying data model is based on the emerging functional, content-centered metadata indexing paradigm using RDF. Linked Data (LD) principles are used for mapping the metadata with tens of interlinked ontologies in the national FinnONTO ontology infrastructure. The contents are also linked with the large LD metadata repository of related cultural heritage content of CultureSampo. BookSampo is actually based on using CultureSampo as a semantic web service, demonstrating the idea of re-using semantic content from multiple perspectives without the need for modifications. Most of the content has been transformed automatically from existing databases, with the help of ontologies derived from thesauri in use in Finland, but in addtion tens of volunteered librarians have participated in a Web 2.0 fashion in annotating and correcting the metadata, especially regarding older litarature. For this purpose, semantic web editing tools and public ONKI ontology services were created and used. The paper focuses on lessons learned in the process of creating the semantic web basis of BookSampo.
Eetu Mäkelä, Aleksi Lindblad, Jari Väätäinen, Rami Alatalo, Osma Suominen and Eero Hyvönen: Discovering Places of Interest through Direct and Indirect Associations in Heterogeneous Sources -- The TravelSampo System. Terra Cognita 2011: Foundations, Technologies and Applications of the Geospatial Web, CEUR Workshop Proceedings, Vol-798, 2011. bib pdf
Linked data related to places has a potential to offer a vastly superior collection of information to base search and recommendation functionality on in eTourism visit planning as well as location-aware mobile applications. Particularly, through linked data, besided places interesting in themselves, it is possible to discover places interesting only through association, such as being the venue for a concert by an artist with an interesting genre. However, in order to harness this collective data source, challenges relating to data heterogeneity, quality, scale, and indexing and querying complexity must be resolved. In this paper, the TravelSampo visit planning and mobile application is presented, which tackles these issues. Using the system, queries describing both simple and complex interests can be run over some 17 million places of interest from over 20 vastly heterogeneous sources.
Kim Viljanen, Jouni Tuominen, Eetu Mäkelä and Eero Hyvönen: Combining Distributed Ontology Repositories into a Global Service. June, 2011. Draft paper. bib pdf
Ontologies and vocabularies are a key resource for creating interoperable metadata on the Semantic Web. To make finding and using ontologies easier, the idea of Ontology Repositories has been introduced with current implementations including e.g. the NCBO Bioportal, ONKI and Cupboard. There is a genuine need for different kinds of Ontology Repositories, each focusing on different kinds specific user-needs, different ontologies and different organizational requirements which cannot be addressed by a single general implementation. However, at the moment each Ontology Repository is a separate island with its own user interfaces and APIs. They also use varying ontology languages such as OWL, SKOS, and RDF Schema. Due to this, global search, browsing, and inference over the repositories is difficult and generally not done which means that, for example, finding and reusing existing ontologies becomes difficult. To address the problems, we have developed a loosely coupled Network of Ontology Repositories (NOR) architecture that makes the repositories globally interoperable while maintaining their unique functionalities and strengths. To participate in the network, each ontology repository is required to implement a shared API. As a proof-of-concept evaluation, we present three case implementations demonstrating different aspects of the NOR approach: 1) internal distributed architecture of ONKI, 2) global search of ONKI and NCBO Bioportal, 3) publishing non-ontological concept collections as NOR endpoints, demonstrated with the semantic portal CultureSampo and the metadata editor SAHA.
Kaisa Hypén and Eetu Mäkelä: An ideal model for an information system for fiction and its application: Kirjasampo and Semantic Web. Library Review, vol. 60, no. 4, April, 2011. bib link
Purpose – Library Director Jarmo Saarti introduced a wide or ideal model for fiction in literature in his dissertation, published in 1999. It introduces those aspects that should be included in an information system for fiction. Such aspects include literary prose and its intertextual references to other works, the writer, readers and critics receptions of the work as well as a researcher s view. It is also important to note how libraries approach a literary work by means of inventory, classification and content description. The most ambiguous of the aspects relates to that context in cultural history, which the work reflects and is a part of. The paper aims to discuss these issues. Design/methodology/approach – Since the model consists of several components which are not found in present library information systems and cannot be implemented by them, a new way had to be found to produce, save, process and present fiction‐related metadata. The Semantic Computing Research Group of Aalto University has developed several Semantic Web services for use in the field of culture, so cooperation with it and the use of Semantic Web tools were a natural starting point for the construction of the new service. Kirjasampo will be based on the Semantic Web RDF data model. The model enables a flexible linking of metadata derived from different sources, and it can be used to build a Semantic Web that can be approached contextually from different angles. Findings – The “semantically enriched” ideal model for fiction has hence been realised, at least to some extent: Kirjasampo supports literature‐related metadata that is more varied than earlier and aims to account for different contexts within literature and connections with regard to other cultural phenomena. It also includes contemporary reviews of works and, as such, readers receptions as well. Modern readers can share their views on works, once the user interface of the server is completed. It will include several features from the Kirjasto 2.0‐application, which enables the evaluation, description and recommendations of works. The service should be online by the end of Spring 2011. Research limitations/implications – The project involves novel collaboration between a public library and a computer science research unit, and utilises a novel approach to the description of fiction. Practical implications – The system encourages user participation in the description of fiction and is of practical benefit to librarians in understanding both how fiction is organised and how users interpret the same. Originality/value – Upon completion, the service will be the first Finnish information system for libraries built with the tools of the Semantic Web which offers a completely new user environment and application for data produced by libraries. It also strives to create a new model for saving and producing data, available to both library professionals and readers. The aim is to save, accumulate and distribute literary knowledge, experiences and silent information.

2010

Tomi Kauppinen, Panu Paakkarinen, Eetu Mäkelä, Heini Kuittinen, Jari Väätäinen and Eero Hyvönen: Geospatio-temporal Semantic Web for Cultural Heritage. Digital Culture and E-Tourism: Technologies, Applications and Management Approaches, 2010. bib pdf link
People frequently need to find knowledge related to places when they plan a leisure trip, when they are executing that plan in a certain place, or when they want to virtually explore a place they have visited in the past. In this chapter we present and discuss a set of methods for searching and browsing spatiotemporally referenced knowledge related to cultural objects, e.g. artifacts, photographs and visiting sites. These methods have been implemented in the semantic cultural heritage portal CULTURESAMPO that offers map-based interfaces for a user to explore hundreds of thousands of content objects and points of interest in Finland. Our goal is to develop and demonstrate novel ways to help the user 1) to decide where to go for a trip, and 2) to learn more about the neighborhoods and points of interest during the visit.
Kaisa Hypén and Eetu Mäkelä: RDF ja FRBRoo: Kirjasammon skeemasta. Informaatiotutkimus, vol. 29, no. 3, 2010. bib pdf
Eetu Mäkelä: View-Based User Interfaces for the Semantic Web. Dissertation, Aalto University, School of Science and Technology, Espoo, November, 2010. D.Sc. dissertation. bib pdf
This thesis explores the possibilities of using the view-based search paradigm to create intelligent user interfaces on the Semantic Web. After surveying several semantic search techniques, the view-based search paradigm is explained, and argued to fit in a valuable niche in the field. To test the argument, numerous portals with different user interfaces and data were built using the paradigm. Based on the results of these experiments, this thesis argues that the paradigm provides a strong, extendable and flexible base on which to built semantic user interfaces. Designing the actual systems to be as adaptable as possible is also discussed.

2009

Tuukka Ruotsalo and Eetu Mäkelä: A Comparison of Corpus-Based and Structural Methods on Approximation of Semantic Relatedness in Ontologies. International Journal On Semantic Web and Information Systems, vol. 5, no. 4, pp. 39-56, IGI Global, 2009. bib pdf link
In this paper, the authors compare the performance of corpus-based and structural approaches to determine semantic relatedness in ontologies. A large light-weight ontology and a news corpus are used as materials. The results show that structural measures proposed by Wu and Palmer, and Leacock and Chodorow have superior performance when cut-off values are used. The corpus-based method Latent Semantic Analysis is found more accurate on specific rank levels. In further investigation, the approximation of structural measures and Latent Semantic Analysis show a low level of overlap and the methods are found to approximate different types of relations. The results suggest that a combination of corpus-based methods and structural methods should be used and appropriate cut-off values should be selected according to the intended use case.
Tomi Kauppinen, Tuukka Ruotsalo, Frédéric Weis, Sylvain Roche, Marco Berni, Eetu Mäkelä, Nima Dokoohaki and Eero Hyvönen: SmartMuseum Knowledge Exchange Platform for Cross-European Cultural Content Integration and Mobile Publication. Proceedings of the CULTURAL HERITAGE on line Empowering users: an active role for user communities, December 15-16, 2009. bib pdf
European museums and other cultural institutions host rich collections that have ability to attract EU citizens and tourists. Cultural objects, e.g. paintings, in these collections are related in many ways and in many cases they refer to same underlying concepts, people and places. The Cultural Heritage Knowledge Exchange Platform, SMARTMUSEUM requires that these collections are interoperable over cultural and language barriers, and provides a mobile publication channel for collections.
Tuukka Ruotsalo, Eetu Mäkelä, Tomi Kauppinen, Eero Hyvönen, Krister Haav, Ville Rantala, Matias Frosterus, Nima Dokoohaki and Mihhail Matskin: Smartmuseum: Personalized Context-aware Access to Digital Cultural Heritage. Proceedings of the International Conferences on Digital Libraries and the Semantic Web 2009 (ICSD2009), September, 2009. Trento, Italy. bib pdf
This paper presents a semantic recommender method and a system for a personalized access to digital cultural heritage through context-aware user pro- filing. Given annotation knowledge-bases, explicit background knowledge in the form of ontologies, a user model capturing the user’s behavior and context, the system produces recommendations. Ontology-based user profiling can be used to reduce cold-start, sparsity and over-specialization problems. In addition, we present a recommendation retrieval method that is based on the vector space model and uses indices that enable fast and scalable implementation of the system.
Eero Hyvönen, Eetu Mäkelä, Tomi Kauppinen, Olli Alm, Jussi Kurki, Tuukka Ruotsalo, Katri Seppälä, Joeli Takala, Kimmo Puputti, Heini Kuittinen, Kim Viljanen, Jouni Tuominen, Tuomas Palonen, Matias Frosterus, Reetta Sinkkilä, Panu Paakkarinen, Joonas Laitio, Katariina Nyberg: CultureSampo - A National Publication System of Cultural Heritage on the Semantic Web 2.0. Proceedings of the 6th European Semantic Web Conference (ESWC2009), Heraklion, Greece, May 31 - June 4, 2009. Springer-Verlag. bib pdf
CULTURESAMPO is an application demonstration of a national level publication system of cultural heritage contents on the Web, based on ideas and technologies of the Semantic (Web and) Web 2.0. On the semantic side, the system presents new solutions to interoperability problems of dealing with multiple ontologies of different domains, and to problems of integrating multiple metadata schemas and cross-domain content into a homogeneous semantic portal. A novelty of the system is to use semantic models based on events and narrative process descriptions for modeling and visualizing cultural phenomena, and for semantic recommendations. On the Web 2.0 side, CULTURESAMPO proposes and demonstrates a content creation process for collaborative, distributed ontology and content development including different memory organizations and citizens. The system provides the cultural heritage contents to end-users in a new way through multiple (nine) thematic perspectives, based on semantic visualizations. Furthermore, CULTURESAMPO services are available for external web-applications to use through semantic AJAX widgets.
Eero Hyvönen, Eetu Mäkelä, Tomi Kauppinen, Olli Alm, Jussi Kurki, Tuukka Ruotsalo, Katri Seppälä, Joeli Takala, Kimmo Puputti, Heini Kuittinen, Kim Viljanen, Jouni Tuominen, Tuomas Palonen, Matias Frosterus, Reetta Sinkkilä, Panu Paakkarinen, Joonas Laitio, Katariina Nyberg: CultureSampo - Finnish Culture on the Semantic Web 2.0. Thematic Perspectives for the End-user. Proceedings, Museums and the Web 2009, Indianapolis, USA, April 15-18, 2009. bib pdf
We present an overview of CultureSampo, an ambitious system for creating a collective semantic memory of the cultural heritage of a nation on the Semantic Web 2.0, combining ideas underlying the Semantic Web and the Web 2.0. The system addresses the semantic web challenge of aggregating highly heterogeneous, cross-domain cultural heritage collections and other contents into a semantically rich intelligent system for human and machine users. At the same time, CultureSampo is an approach to solve the social and practical Web 2.0 challenge of organizing the underlying collaborative ontology development and content creation work of memory organizations and citizens. This paper focuses on CultureSampo’s search, recommendation, and visualization services for the end-users. The key idea here is to access cultural heritage on the Semantic Web through nine “thematic perspectives”, such as places on the maps, the social network of cultural persons, timelines, and narrative texts, e.g. biographies and literary works.
Eero Hyvönen, Eetu Mäkelä, Tomi Kauppinen, Olli Alm, Jussi Kurki, Tuukka Ruotsalo, Katri Seppälä, Joeli Takala, Kimmo Puputti, Heini Kuittinen, Kim Viljanen, Jouni Tuominen, Tuomas Palonen, Matias Frosterus, Reetta Sinkkilä, Panu Paakkarinen, Joonas Laitio, Katariina Nyberg: CultureSampo - Finnish Cultural Heritage Collections on the Semantic Web 2.0. Proceedings of the 1st International Symposium on Digital Humanities for Japanese Arts and Cultures (DH-JAC-2009), Ritsumeikan University, Kyoto, Japan, March, 2009. bib pdf
This paper presents an overview of the SemanticWeb 2.0 application CultureSampo, an ambitious system for creating a collective semantic memory of the cultural heritage of a nation on the Semantic Web 2.0, combining ideas underlying the Semantic Web and the Web 2.0. The system addresses the semantic web challenge of aggregating highly heterogeneous, cross-domain cultural heritage content into a semantically rich intelligent system for human and machine users. At the same time, CultureSampo is an approach to solve the social and practical Web 2.0 challenge of organizing the underlying collaborative ontology development and content creation work of memory organizations and citizens.

2008

Tuukka Ruotsalo, Katri Seppälä, Kim Viljanen, Eetu Mäkelä, Jussi Kurki, Olli Alm, Tomi Kauppinen, Jouni Tuominen, Matias Frosterus, Reetta Sinkkilä and Eero Hyvönen: Ontology-­based Approach for Interoperability of Digital Collections. Signum, no. 5, 2008. bib pdf
This paper presents solutions and lessons learned in FinnONTO project carried out in Finland in 2003–2007. The paper focuses on three aspects of interoperability of digital collections. First, transforming thesauri to ontologies. Second, publishing ontologies for the use of indexers and content providers. Third, ontology based methods for improving end user access to digital collections.  The first aspect is analysed through case studies done with Finnish thesauri. The second is discussed by presenting the ONKI ontology server. The last aspect is demonstrated in the scope of the semantic portal CultureSampo for publishing cultural heritrage on the Semantic Web.
Eero Hyvönen, Kim Viljanen, Jouni Tuominen, Katri Seppälä, Tomi Kauppinen, Matias Frosterus, Reetta Sinkkilä, Jussi Kurki, Olli Alm, Eetu Mäkelä and Joonas Laitio: National Ontology Infrastructure Service ONKI. Oct 1, 2008. bib pdf
This paper presents the national level cross-domain ontology and ontology service infrastructure ONKI used in Finland. The novelty of ONKI is based on two ideas. First, the core ontologies are developed collaboratively by experts transforming thesauri into mutually aligned lightweight ontologies, based on a large top ontology that is extended by various domain specific ontologies. Second, the National Ontology Service ONKI has been implemented for publishing ontologies cost-efficiently as ready to use services. ONKI provides legacy and other applications with ready to use functionalities for using ontologies on the HTML level by Ajax and semantic widgets. ONKI has been used in various applications for creating mash-up applications in a way analogous to using Google Maps, but in our case external applications are mashed-up with ontology support for indexing and information retrieval.
Eero Hyvönen, Eetu Mäkelä, Tomi Kauppinen, Olli Alm, Jussi Kurki, Tuukka Ruotsalo, Katri Seppälä Kim Viljanen, Jouni Tuominen, Tuomas Palonen, Matias Frosterus, Reetta Sinkkilä, Panu Paakkarinen, Joonas Laitio, Katariina Nyberg: CultureSampo - A Collective Memory of Finnish Cultural Heritage on the Semantic Web 2.0. Semantic Computing Research Group, Helsinki University of Technology and University of Helsinki, Sept 29, 2008. bib pdf
This paper presents the Semantic Web 2.0 application CULTURESAMPO, an ambitious system of creating a collective semantic memory of the cultural heritage of a nation on the Semantic Web 2.0, combining ideas underlying the Semantic Web and the Web 2.0. The system addresses the semantic challenge of aggregating highly heterogeneous, cross-domain cultural heritage into a semantically rich intelligent system for human and machine users. At the same time, CULTURESAMPO is an approach to solve the social and practical Web 2.0 challenge of organizing the underlying collaborative ontology development and content creation work of memory organizations and citizens.
Reetta Sinkkilä, Eetu Mäkelä, Tomi Kauppinen and Eero Hyvönen: Combining Context Navigation with Semantic Autocompletion to Solve Problems in Concept Selection. First International Workshop on Semantic Metadata Management and Applications, SeMMA 2008, Located at the Fifth European Semantic Web Conference (ESWC 2008), Tenerife, Spain, June 2nd, 2008. Proceedings (Khalid Belhajjame, Mathieu d Aquin, Peter Haase and Paolo Missier (eds.)), CEUR Workshop Proceedings, vol. 346, pp. 61-68, CEUR-WS.org, Tenerife, Spain, June 1-5, 2008. bib pdf
Many tasks on the semantic web require the user to choose concepts from a limited vocabulary e.g. for describing an indexed resource or for use in semantic search. Semantic autocompletion interfaces offer an efficient way for concept selection. However, these interfaces usually do not expose the semantic context of the matched concepts, thereby making it hard to know if a matched concept is the right one, as well as hiding possibly more appropriate choices. Ontology browsers, on the other hand, show context but do not allow quick discovery or embedding into other applications. To lessen these problems, we present an interface combining semantic autocompletion with in-place ontological context navigation. Because required context differs between ontologies, the implementation was designed to make it easy to add different contexts and visualizations. To test the applicability of our idea and implementation the, system was tested on three ontologies with different requirements and structure.
Eero Hyvönen, Eetu Mäkelä, Tuukka Ruotsalo, Tomi Kauppinen, Olli Alm, Jussi Kurki, Joeli Takala, Kimmo Puputti and Heini Kuittinen: CultureSampo-Finnish Culture on the Semantic Web. Posters of the 5th European Semantic Web Conference 2008 (ESWC 2008), Tenerife, Spain, June 1-5, 2008. bib pdf
This paper presents the semantic portal CULTURESAMPO---Finnish Culture on the Semantic Web . The portal provides memory organizations and other cultural content publishers with a national, shared semantic publication channel for heteroge- nous cultural contents. The content comes from over ten organizations and is annotated using various ontologies of the FinnONTO infrastructure. For the end-user, intel- ligent semantic search, recommendation, and visualization services for accessing and learning about cultural heritage are provided.

2007

Eetu Mäkelä, Osma Suominen and Eero Hyvönen: Automatic Exhibition Generation Based on Semantic Cultural Content. Proceedings of the Cultural Heritage on the Semantic Web Workshop at the 6th International Semantic Web Conference (ISWC 2007), Busan, Korea, November 12, 2007. bib pdf
In this paper, we argue for a need to shift focus in semantic search from the items themselves to using them as lenses to wider topics. A system for doing this in the cultural heritage domain is presented, duplicating on the web the way exhibitions in the real world are organized. An interface for specifying such exhibitions is presented, combining a general narrative pattern with semantic autocompletion and the novel concept of domain-centric view-based search. This also solves a number of problems view-based search has previously encountered in the cultural heritage domain. Presented also are multiple visualizations for the exhibition, supporting the user in making sense of the data and in doing exploratory search.
Eetu Mäkelä, Tuukka Ruotsalo and Eero Hyvönen: Automatic Exhibition Generation Based on Semantic Cultural Content. Poster proceedings of the 6th International Semantic Web Conference, Busan, Korea, November 11-15, 2007. bib pdf
This paper shortly presents an automatic exhibition generation interface that turns the focus of semantic search from search items to the concepts they are annotated with.
Eetu Mäkelä, Reetta Sinkkilä and Eero Hyvönen: Combining Cross-ontology Navigation with Semantic Autocompletion. Poster proceedings of the 6th International Semantic Web Conference, Busan, Korea, November 11-15, 2007. bib pdf
Semantic autocompletion interfaces offer an efficient way for concept selection useful in both search and annotation applications. However, these interfaces usually do not expose the semantic context of the matched concepts, thereby making it hard to know if a matched concept is the right one, as well as hiding possibly more appropriate choices. To lessen these problems, we present an in-place ontological context navigation interface to be used with semantic autocompletion.
Eetu Mäkelä, Tuukka Ruotsalo and Eero Hyvönen: Domain-Centric View-Based Search. Poster proceedings of the 6th International Semantic Web Conference, Busan, Korea, November 11-15, 2007. bib pdf
In current Semantic Web view-based search systems views are formed by selecting properties and enumerating all their values as selections. This approach breaks down with multiple content types, such as in the cultural heritage domain, because the number of differing properties, and therefore views becomes unmanageable. We propose a novel solution termed Domain-Centric View-Based Search, in which views are created based on common property ranges and domain ontologies.
Eetu Mäkelä, Kim Viljanen, Olli Alm, Jouni Tuominen, Onni Valkeapää, Tomi Kauppinen, Jussi Kurki, Reetta Sinkkilä, Teppo Känsälä, Robin Lindroos, Osma Suominen, Tuukka Ruotsalo and Eero Hyvönen: Enabling the Semantic Web with Ready-to-Use Web Widgets. Proceedings of the First Industrial Results of Semantic Technologies Workshop, ISWC2007, November 11, 2007. bib pdf
A lot of functionality is needed when an application, such as a museum cataloguing system, is extended with semantic capabilities, for example ontological indexing functionality or multi-facet search. To avoid duplicate work and to enable easy and cost-efficient integration of information systems with the Semantic Web, we propose a web widget approach. Here, data sources are combined with functionality into readyto-use software components that allow adding semantic functionality to systems with just a few lines of code. As a proof of the concept, we present a collection of general semantic web widgets and case applications that use them, such as the ontology server ONKI, the annotation editor SAHA and the culture portal CultureSampo.
Kim Viljanen, Jouni Tuominen, Eero Hyvönen, Eetu Mäkelä and Osma Suominen: Extending Content Management Systems with Ontological Annotation Capabilities. Poster proceedings of the 6th International Semantic Web Conference, Busan, Korea, November 11-15, 2007. bib pdf
Producing semantic metadata requires efficient methods, e.g., concept finding, for accessing and using ontologies. To add such functionalities to metadata applications such as cataloging systems in museums, we propose a \emphmash-up approach where ready-to-use user interface components for using specific ontologies are made available to be integrated into applications. As a proof-of-concept, we present the \emphOntology Service ONKI wich implements semantic autocompletion concept search and concept browsing for ontologies as shared mash-up components.
Eero Hyvönen, Tuukka Ruotsalo, Thomas Häggström, Mirva Salminen, Miikka Junnila, Mikko Virkkilä, Mikko Haaramo, Eetu Mäkelä, Tomi Kauppinen and and Kim Viljanen: CultureSampo-Finnish Culture on the Semantic Web: The Vision and First Results (based on the STeP 2006 paper below). In: K. Robering (ed.): Information Technology for the Virtual Museum. LIT Verlag, Berlin., Nov, 2007. bib pdf
This paper concerns the idea of publishing heterogenous cultural content on the Semantic Web. By heterogenous content we mean metadata describing potentially any kind of cultural objects, including artifacts, photos, paintings, videos, folklore, cultural sites, cultural process descriptions, biographies, history etc. The metadata schemas used are different and the metadata may be represented at different levels of semantic granularity. This work is an extension to previous research on semantic cultural portals, such as MuseumFinland, that are usually based on a shared homogeneous schema, such as Dublin Core, and focus on content of similar kinds, such as artifacts. Our experiences suggest that a semantically richer event-based knowledge representation scheme than traditional metadata schemas is needed in order to support reasoning when performing semantic search and browsing. The new key idea is to transform different forms of metadata into event-based knowledge about the entities and events that take place in the world or in fiction. This approach facilitates semantic interoperability and reasoning about the world and stories at the same time, which enables implementation of intelligent services for the end-user. These ideas are addressed by presenting the vision and solution approaches taken in two prototype implementations of a new kind of cross-domain semantic cultural portal “CULTURESAMPO—Finnish Culture on the Semantic Web”.
Eero Hyvönen, Joeli Takala, Olli Alm, Tuukka Ruotsalo and Eetu Mäkelä: Semantic Kalevala - Accessing Cultural Contents Through Semantically Annotated Stories. Proceedings of the Cultural Heritage on the Semantic Web Workshop at the 6th International Semantic Web Conference (ISWC 2007), Busan, Korea, Nov, 2007. bib pdf
An event-based approach is presented for annotating events and narrative structures underlying texts and stories semantically. The idea is applied to using the Finnish national epic Kalevala for accessing related cultural contents, such as artifacts, paintings etc. in a semantic portal.
Eero Hyvönen, Kim Viljanen, Eetu Mäkelä, Tomi Kauppinen, Tuukka Ruotsalo, Onni Valkeapää, Katri Seppälä, Osma Suominen, Olli Alm, Robin Lindroos, Teppo Känsälä, Riikka Henriksson, Matias Frosterus, Jouni Tuominen, Reetta Sinkkilä and Jussi Kurki: Elements of a National Semantic Web Infrastructure - Case Study Finland on the Semantic Web (Invited paper). Proceedings of the First International Semantic Computing Conference (IEEE ICSC 2007), Irvine, California, September, 2007. IEEE Press. bib pdf
This article presents the vision and results of creating the basis for a national semantic web content infrastructure in Finland in 2003-2007. The main elements of the infrastructure are shared and open metadata schemas, core ontologies, and public ontology services. Several practical applications testing and demonstrating the usefulness of the infrastructure are overviewed in the fields of eCulture, eHealth, eGovernment, eLearning, and eCommerce.
Kim Viljanen, Eero Hyvönen, Eetu Mäkelä, Osma Suominen and Jouni Tuominen: Mash-up Ontology Services for the Semantic Web. Demo track at the European Semantic Web Conference ESWC 2007, Innsbruck, Austria, June 4-5, 2007. bib pdf
We present ONKI ontology server, a mash-up approach for integrating ontology library services with semantic web applications. The idea of ONKI is to provide applications with ready-to-use ontology service functionalities, such as semantic autocompletion, browsing, and annotation support, at the user interface level using AJAX mash-up technologies. The system is being integrated with various semantic web applications.

2006

Eetu Mäkelä: Harnessing Folksonomies for Search. Proceedings of the Seminar on Web 2.0, Laboratory of Media Technology, Helsinki University of Technology (TKK), December, 2006. bib pdf
This paper analyses folksonomies, an emergent web 2.0 technology. Folksonomies are found to be primarily a social dynamic phenomenon, and several key tensions are hypothesised that keep the folksonomy community vibrant. Strengths and weaknesses of folksonomies are analyzed w.r.t applicability to browsing and search, and suggestions are given on how to alleviate search problems by bringing in additional semantics into folksonomies, while trying to avoid upsetting the delicate social balances discovered.
Eetu Mäkelä, Eero Hyvönen and Samppa Saarela: Ontogator -- A Semantic View-based Search Engine Service for Web Applications. Proceedings of the 5th International Semantic Web Conference (ISWC 2006), Nov, 2006. bib pdf
View-based search provides a promising paradigm for formulating complex semantic queries and representing results on the Semantic Web. A challenge for the application of the paradigm is the complexity of providing view-based search services through application programming interfaces (API) and web services. This paper presents a solution on how semantic view-based search can be provided efficiently through an API or as web service to external applications. The approach has been implemented as the open source tool Ontogator, that has been applied successfully in several practical semantic portals on the web.
Eero Hyvönen, Tuukka Ruotsalo, Thomas Häggström, Mirva Salminen, Miikka Junnila, Mikko Virkkilä, Mikko Haaramo, Eetu Mäkelä, Tomi Kauppinen and and Kim Viljanen: CultureSampo-Finnish Culture on the Semantic Web: The Vision and First Results. Developments in Artificial Intelligence and the Semantic Web - Proceedings of the 12th Finnish AI Conference STeP 2006, October 26-27, 2006. bib pdf
This paper concerns the idea of publishing heterogenous cultural content on the Semantic Web. By heterogenous content we mean metadata describing potentially any kind of cultural objects, including artifacts, photos, paintings, videos, folklore, cultural sites, cultural process descriptions, biographies, history etc. The metadata schemas used are different and the metadata may be represented at different levels of semantic granularity. This work is an extension to previous research on semantic cultural portals, such as MuseumFinland, that are usually based on a shared homogeneous schema, such as Dublin Core, and focus on content of similar kinds, such as artifacts. Our experiences suggest that a semantically richer event-based knowledge representation scheme than traditional metadata schemas is needed in order to support reasoning when performing semantic search and browsing. The new key idea is to transform different forms of metadata into event-based knowledge about the entities and events that take place in the world or in fiction. This approach facilitates semantic interoperability and reasoning about the world and stories at the same time, which enables implementation of intelligent services for the end-user. These ideas are addressed by presenting the vision and solution approaches taken in two prototype implementations of a new kind of cross-domain semantic cultural portal “CULTURESAMPO—Finnish Culture on the Semantic Web”
Kim Viljanen, Teppo Känsälä, Eero Hyvönen and Eetu Mäkelä: ONTODELLA - A Projection and Linking Service for Semantic Web Applications. Proceedings of the 17th International Conference on Database and Expert Systems Applications (DEXA 2006), Krakow, Poland, pp. 370-376, IEEE, September 4-8, 2006. bib pdf ps
Content in semantic web portals is often projected along application specific navigational taxonomies and linked semantically. This paper presents a logic-based method and a server ONTODELLA for these tasks. We argue that logic rules between the content layer and the application layer add flexibility and better architectural separation of content and functionality. The system has been implemented and applied succesfully in several semantic portals.
Eero Hyvönen and Eetu Mäkelä: Semantic Autocompletion. Proceedings of the first Asia Semantic Web Conference (ASWC 2006), Beijing, Springer-Verlag, New York, August 4-9, 2006. bib pdf
This paper generalizes the idea of traditional syntactic text autocompletion onto the semantic level. The idea is to autocomplete typed text into ontological categories instead of words in a vocabulary. The idea has been implemented and its application for semantic indexing and content-based information retrieval in multi-facet search is proposed. Four operational semantic portals on the web using the implementation are presented as application cases.
Eetu Mäkelä: View-Based Search Interfaces for the Semantic Web. MSc Thesis, University of Helsinki, June, 2006. bib pdf
This thesis explores the possibilities of using the view-based search paradigm to create intelligent search interfaces on the Semantic Web. After surveying several current semantic search techniques, the view-based search paradigm is explained, and argued to fit in a valuable niche in the field. To test the argument, OntoViews, a semantic view-based search portal creation tool was designed and implemented, and eight portals with five vastly different user interfaces were built using it. Based on the results of these experiments, this thesis argues that the paradigm, particularly as implemented in the OntoViews tool provides a strong, extensible and flexible base on which to built semantic search applications. The particular problems faced in applying view-based search for semantic interfaces are noted, along with explanations on how they were solved in the OntoViews architecture. Finally, directions and ideas for future research are presented for both the paradigm and the implementation architecture, respectively.

2005

Eero Hyvönen, Eetu Mäkelä, Mirva Salminen, Arttu Valo, Kim Viljanen, Samppa Saarela, Miikka Junnila and Suvi Kettula: MuseumFinland - Finnish Museums on the Semantic Web. Journal of Web Semantics, vol. 3, no. 2, pp. 25, 2005. bib pdf
This article presents the semantic portal MUSEUMFINLAND for publishing heterogeneous museum collections on the Semantic Web. It is shown how museums with their semantically rich and interrelated collection content can create a large, consolidated semantic collection portal together on the web. By sharing a set of ontologies, it is possible to make collections semantically interoperable, and provide the museum visitors with intelligent content-based search and browsing services to the global collection base. The architecture underlying MUSEUMFINLAND separates generic search and browsing services from the underlying application dependent schemas and metadata by a layer of logical rules. As a result, the portal creation framework and software developed has been applied successfully to other domains as well. MUSEUMFINLAND got the Semantic Web Challence Award (second prize) in 2004.
Eetu Mäkelä: Survey of Semantic Search Research. Proceedings of the Seminar on Knowledge Management on the Semantic Web, Department of Computer Science, University of Helsinki, 2005. bib pdf
This paper surveys the research field of semantic search, i.e. search utilizing semantic techniques or search of formally annotated semantic content. The survey identifies and discusses various prevalent research directions in se- mantic search, as well as extracts common methodology used in them.
Eetu Mäkelä, Kim Viljanen, Petri Lindgren, Mikko Laukkanen and Eero Hyvönen: Semantic Yellow Page Service Discovery: The Veturi Portal. Poster paper, 4th International Semantic Web Conference, Nov, 2005. bib pdf
A prototype semantic yellow page service portal is described. Our idea is to represent service offerings as events and processes in terms of ontologies. Based on versatile semantic descriptions, users can be provided with a flexible view-based search engine enhanced with semantic text autocompletion.
Eetu Mäkelä, Eero Hyvönen and Teemu Sidoroff: View-Based User Interfaces for Information Retrieval on the Semantic Web. Proceedings of the ISWC-2005 Workshop End User Semantic Web Interaction, Nov, 2005. bib pdf
This paper argues for using the multi-facet search paradigm as a basis in information retrieval on the Semantic Web. To support the argument, two user interfaces for extant semantic web portals based on the concept of viewhierarchies are presented. The interfaces described reveal and contrast how the view-based paradigm can be applied to support both browsing and searching strategies in information retrieval in applications using different domain and annotation ontologies. New semantics-based user interface elements complementing the basic paradigm are also discussed.

2004

Mikko Laukkanen, Kim Viljanen, Mikko Apiola, Petri Lindgren, Eetu Mäkelä, Samppa Saarela and Eero Hyvönen: Towards Semantic Web-Based Yellow Page Directory Services. Presented at the Third International Semantic Web Conference (ISWC2004), Hiroshima, Japan, Nov, 2004. Poster paper. bib pdf
This paper describes the ongoing work of IWebS (Intelligent Web Services) project, which studies the possibilities of the Semantic Web technology in creating a yellow page directory service for end-users. We propose an ontology-based mechanism for both advertising and finding the services. The essential parts of the system are ontologies for describing and storing service advertisements, a semantic service finder for the enduser, and a semantic service annotation editor for service providers.
Eetu Mäkelä, Eero Hyvönen, Samppa Saarela and Kim Viljanen: OntoViews - A Tool for Creating Semantic Web Portals. Proceedings of the 3rd International Semantic Web Conference (ISWC 2004), May, 2004. bib pdf
This paper presents a semantic web portal tool ONTOVIEWS for publishing RDF content on the web. ONTOVIEWS provides the portal designer with a content-based search engine server, Ontogator, and a link recommendation system server, Ontodella. The user interface is created by combining these servers with the Apache Cocoon framework. From the end-user s viewpoint, the key idea of ONTOVIEWS is to combine the multi-facet search paradigm, developed within the information retrieval research community, with semantic web RDFS ontologies, and extend the search service with a semantic browsing facility based on ontological reasoning. ONTOVIEWS is presented from the view points of the end user, architecture, and implementation. The implementation described is modular, easily modified and extended, and provides a good practical basis for creating semantic portals on the web. As a proof of concept, application of ONTOVIEWS to a deployed semantic web portal is discussed.
Eero Hyvönen, Miikka Junnila, Suvi Kettula, Eetu Mäkelä, Samppa Saarela, Mirva Salminen, Ahti Syreeni, Arttu Valo and Kim Viljanen: Publishing Museum Collections on the Semantic Web - the MuseumFinland Portal. Proceedings of WWW2004, New York, Alternate Track Papers and Posters, May, 2004. bib pdf
Museum collections contain large amounts of data and semantically rich, mutually interrelated metadata in heterogeneous databases. The publication of museum collections on the web is therefore a very promising application domain for semantic web techniques. We present a semantic web portal called MUSEUMFINLAND - Finnish Museums on the Semantic Web , that contains some 4,000 cultural artifacts from the collections of three museums using three different database schemas and database systems. The system is based on seven RDF(S) ontologies consisting of some 10,000 classes and individuals.
Eero Hyvönen, Samppa Saarela, Kim Viljanen, Eetu Mäkelä, Arttu Valo, Mirva Salminen, Suvi Kettula and Miikka Junnila: A Cultural Community Portal for Publishing Museum Collections on the Semantic Web. Proceedings of 16th European Conference on Artificial Intelligence (ECAI2004), Workshop on Application of Semantic Web Technologies to Web Communities, 2004. bib pdf
This paper presents a deployed semantic web application in the cultural domain: the semantic portal MUSEUMFINLAND. It is a demonstration of a community portal and a publication channel by which heterogeneous collection database contents of different museums can be published on the Semantic Web. By semantic web techniques, it is possible to make collections semantically interoperable and provide the museum visitors with intelligent content-based search and browsing services to the global collection base.
Eero Hyvönen, Miikka Junnila, Suvi Kettula, Eetu Mäkelä, Samppa Saarela, Mirva Salminen, Ahti Syreeni, Arttu Valo and Kim Viljanen: Finnish Museums on the Semantic Web. User s Perspective on MuseumFinland. Proceedings of Museums and the Web 2004 (MW2004), 2004. bib
This paper presents a semantic portal, MuseumFinland, for publishing heterogeneous museum collections on the Semantic Web. The application is presented from the viewpoints of the end-user and the museums providing the contents. By semantic Web techniques, it is possible to make collections semantically interoperable and provide museum visitors with intelligent content-based search and browsing services to the global collection base. By using the MuseumFinland approach, the museums with their semantically rich and interrelated collection content can create consolidated semantic collection portals together on the Web.
Eero Hyvönen, Samppa Saarela, Kim Viljanen, Eetu Mäkelä, Arttu Valo, Mirva Salminen, Suvi Kettula and Miikka Junnila: A Semantic Portal for Publishing Museum Collections on the Web. Proceedings of ECAI/PAIS 2004, 2004. bib pdf
This paper presents the semantic portal MUSEUMFINLAND for publishing museum collections on the Semantic Web. It is shown how museums with their semantically rich and interrelated collection content can create a large, consolidated semantic collection portal together on the web. By semantic web techniques, it is possible to make collections semantically interoparable and provide the museum visitors with inntelligent content-based search and browsing services to the global collection base.

(in total: 70 publications)

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