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.

Ontologiat ovat keskeinen osa semanttista webiä: ne toimivat yhteisinä jaettuina käsitteistöinä, joiden avulla tietokoneet voivat käsitellä tietoa älykkäämmin. Jotta eri toimijat voivat hyödyntää yhteisiä käsitteistöjä sovelluksissaan, ontologiat on julkaistava heidän käyttöönsä. Yksinkertaisimmillaan ontologiat voidaan julkaista tiedostomuodossa. Tällöin jokainen toimija joutuu toteuttamaan itse toiminnallisuuksia ontologioiden hyödyntämiseen. Koska osa toiminnallisuuksista on yleisiä, useissa järjestelmissä toistuvia, niiden toteuttaminen valmiina palveluina on mielekästä. Palveluita voidaan tarjota ihmiskäyttäjille käyttöliittymäkomponentteina sekä ohjelmalliseen käyttöön rajapintoina, joita käyttämällä toiminnallisuudet voidaan integroida asiakasjärjestelmiin. Tässä artikkelissa kuvataan ontologioiden käyttäjäryhmien tarpeita sekä ontologiapalveluiden toteutuksia. Yleisten ontologioiden käyttämiseen liittyvien toiminnallisuuksien tarjoamiseksi esitetään ontologiapalvelu ONKI, joka on osa Suomalaiset semanttisen webin ontologiat -hankesarjassa (FinnONTO, 2003–2012) kehitettyä ontologiainfrastruktuuria. Artikkeli perustuu Jouni Tuomisen pro gradu -työhön, jolle Tietojenkäsittelytieteen Seura ry myönsi lukuvuoden 2009–2010 pro gradu -palkinnon. Tutkimustyöhön ovat osallistuneet myös Kim Viljanen ja Eero Hyvönen.

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.

We present a comprehensive system for producing interoperable metadata for Linked Open datasets and governmental datasets published in various formats.

Semantic and context knowledge have been envisioned as an appropriate solution to deal with the information overload in mobile Web information access. Semantic Web technologies provide a solid base for standard representation of Web data and have been successfully used to support information retrieval and filtering, but few have explored their full potential in context-aware mobile scenarios, where information is connected to their physical counterparts in the real world and personalized for users. We present the SMARTMUSEUM system, a mobile tour guide to support information needs of tourists in on-site, context-aware access to cultural heritage. The SMARTMUSEUM system utilizes Semantic Web languages as the data representation format, makes use of ontologies to map content descriptions and sensor inputs to user profiles and to background knowledge that is consumed by a novel information filtering framework. The system has empirically proven information filtering performance in laboratory experiments and in real world user trials.

We consider ontology evolution in a system of light-weight Linked Data ontologies, aligned with each other to form a larger ontology system. When one ontology changes, the human editor must keep track of the actual changes and of the modifications needed in the related ontologies in order to keep the system consistent. This paper presents an analysis tool MUTU, by which such changes and their potential effects on other ontologies can be found. Such an analysis is useful for the ontology editors for understanding the differences between ontology versions, and for updating linked ontologies when changes occurred in other components of an ontology system.

Data quality is a growing concern on the Semantic Web. The amount of data available is growing faster than ever, and the emphasis thus far has been on creating and interlinking data without much regard to how good the data actually is. The trend is shifting from creating new data to refining what already exists. Data quality is a subjective concept and a formal representation for it is often troublesome. First, we must define what is meant by data quality - what are the different facets of the concept. Second, a way for representing this quality must be found. Third, actual processes to refine data and improve its quality and ways to take data quality into account on the Semantic Web must be developed. This work presents some solutions to the problem. Many ways to annotate quality metadata as RDF are first discovered, along with their pros and cons. A framework for managing RDF-based quality metadata is presented, with a set of tools for specifically managing the quality annotations. Additionally, an automatic annotation system and a schema validation system, within the restraints of the open world assumption, have been designed, implemented and integrated into the framework. The system has been tested using real life datasets with promising first results.

Semantic web technologies have introduced the idea of annotating content in terms of concepts taken from ontologies. Since concepts are defined in terms of properties and relations to other concepts, descriptions grow up into larger RDF graphs that can be used as a basis for data integration and intelligent information retrieval. Since ontologies do not typically contain all the possible concepts needed for annotation, it is usually necessary to offer the annotator the possibility to introduce new free keywords or tags in addition to the predefined ontology concepts. The problem then is that free keywords/tags do not have ontological connections to the rest of the RDF graph, unless such relations are defined by the annotator.We present a process for integrating free keywords into the ontological framework, and a practical tool implementation of it, discussing the challenges and possibilities introduced by the system. We also describe a case study performed for the Finnish Defence Forces, where the tool is used for creating a faceted semantic search portal featuring the free keywords and the ontological concepts at the same time.

Biodiversity management requires the usage of heterogeneous biological information from multiple sources. Indexing, aggregating, and finding such information is based on names and taxonomic knowledge of organisms. However, taxonomies change in time due to new scientific findings, opinions of authorities, and changes in our conception about life forms. Furthermore, organism names and their meaning change in time, different authorities use different scientific names for the same taxon in different times, and various vernacular names are in use in different languages. This makes data integration and information retrieval difficult without detailed biological information. This paper introduces a meta-ontology for managing the names and taxonomies of organisms, and presents three applications for it: 1) publishing biological species lists as ontology services (ca. 20 taxonomies including more than 80,000 names), 2) collaborative management of the vernacular names of vascular plants (ca. 26,000 taxa), and 3) management of individual scientific name changes based on research results, covering a group of beetles. The applications are based on the databases of the Finnish Museum of Natural History and are used in a living lab environment on the web.

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.

The number of open datasets available on the web is increasing rapidly with the rise of the Linked Open Data (LOD) cloud and various governmental efforts for releasing public data in different formats, not only in RDF. The aim in releasing open datasets is for developers to use them in innovative applications, but the datasets need to be found first and metadata available is often minimal, heterogeneous, and distributed making the search for the right dataset often problematic. To address the problem, we present DataFinland, a semantic portal featuring a distributed content creation model and tools for annotating and publishing metadata about LOD and non-RDF datasets on the web. The metadata schema for DataFinland is based on a modified version of the voiD vocabulary for describing linked RDF datasets, and annotations are done using an online metadata editor SAHA connected to ONKI ontology services providing a controlled set of annotation concepts. The content is published instantly on an integrated faceted search and browsing engine HAKO for human users, and as a SPARQL endpoint and a source file for machines. As a proof of concept, the system has been applied to LOD and Finnish governmental datasets.

Structured semantic metadata about unstructured web documents can be created using automatic subject indexing methods, avoiding laborious manual indexing. A succesful automatic subject indexing tool for the web should work with texts in multiple languages and be independent of the domain of discourse of the documents and controlled vocabularies. However, analyzing text written in a highly inflected language requires word form normalization that goes beyond rule-based stemming algorithms. We have tested the state-of-the art automatic indexing tool Maui on Finnish texts using three stemming and lemmatization algorithms and tested it with documents and vocabularies of different domains. Both of the lemmatization algorithms we tested performed significantly better than a rule-based stemmer, and the subject indexing quality was found to be comparable to that of human indexers.

This master s thesis explores a way in which documents can be automatically classified based on their contents. Automatic classification of data is one of the main applications of machine learning. With the help of already classified data a model for the most likely class can be learned. Whether adding background knowledge from ontologies can be added to the model in order to improve the classification accuracy, is also explored in this master s thesis. A new machine learning model is introduced that incorporates ontology information. The proposed method for learning a classification model and enhancing it with ontology information is used in a case study for the Finnish National Archives and a set of digital documents that have been manually classified. An RDF schema for representing documents, sentences and words is created in order to prepare tha data for the machine learning analysis. The words are put into base form and matched semi-automatically with concepts of the General Finnish Ontology YSO. Then the ontology enhanced model is applied on the data and the most likely classes for documents are learned. The master s thesis shows that the classification accuracy of the model increases when ontology information is added to it.

Ontologies and vocabularies are a key resource for creating interoperable metadata on the Semantic Web. To make the finding and using ontologies easier, the idea of Ontology Repositories have been introduced with current implementations including e.g. the NCBO Bioportal, ONKI and Cupboard. 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, RDF Schema and others. Due to this, global search, browsing, and inference over the repositories is difficult and generally not done. At the same time, 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 can not be addressed by a single global implementation. Since there are benefits of having interoperability among the repositories, we have developed a loosely coupled Network of Ontology Repository (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, we present a global metasearch prototype for searching simultaneously hundreds of ontologies in the ONKI and NCBO Bioportal repositories.

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.

Ontology repository systems are used for publishing and sharing ontologies and vocabularies for content indexing, information retrieval, content integration, and other purposes. However, interlinking these distributed repositories to provide global search and browsing over the repositories has not been made. In the spirit of Linked Open Data, we propose creating a network of Linked Open Ontology Services (LOOS) consisting of ontology repositories that publish their content using a shared API. To test the approach, we have defined an HTTP API and present a proof-of-concept implementation consisting of three client applications that are used for accessing a LOOS network of over 50 ontology servers, part of the Ontology Library Service ONKI.

Ontology repository systems are used for publishing and sharing ontologies. However, currently the repositories form separate islands of ontologies, which hinders the user from finding and utilizing the most suitable ontological concepts and ontologies on a global level. In contrast, this paper presents the idea of creating a network of Linked Open Ontology Services (LOOS) based on a set of ontology services that publish their content via a shared API. This facilitates global search and browsing over all ontologies in the network. LOOS has been implemented in the National Finnish Ontology Service ONKI serving currently 79 ontologies.

Finding ontologies and concepts from a collection of ontologies is a recurring task in many use cases, such as content indexing, searching, and ontology developing. To facilitate this, efficient search and browsing methods are needed. This paper introduces ONKI2, an ontology browser providing a user interface for a repository of ontologies. The system provides a multi-facet search facility for finding an ontology. Finding concepts is supported by autocompletion-based text search that can be refined with additional restrictions. ONKI2 is in use in the Finnish Ontology Library Service ONKI for a collection of 79 ontologies and vocabularies.

Ontologiat luovat semanttisen webin perustan: ne toimivat yhteisinä jaettuina käsitteistöinä, joiden avulla tietokoneet voivat käsitellä tietoa älykkäämmin. Jotta eri toimijat voivat hyödyntää yhteisiä käsitteistöjä sovelluksissaan, ontologiat on julkaistava heidän käyttöönsä. Yksinkertaisimmillaan ontologiat voidaan julkaista datana, tiedostomuodossa. Tällöin jokainen toimija joutuu toteuttamaan itse toiminnallisuuksia ontologioiden hyödyntämiseen. Osa toiminnallisuuksista on yleisiä, useissa järjestelmissä toistuvia, kuten ontologian visualisointi, selaaminen ja käsitehaku. On kuitenkin kustannustehokkaampaa toteuttaa yleisiä ontologiatoiminnallisuuksia valmiina palveluina. Palveluita voidaan tarjota ihmiskäyttäjille käyttöliittymäkomponentteina sekä ohjelmalliseen käyttöön rajapintoina, joita käyttämällä toiminnallisuudet voidaan integroida asiakasjärjestelmiin. Lisäksi käytettäessä ontologioita palveluina toimijoiden käytössä on aina ontologioiden ajantasaiset versiot. Tässä tutkielmassa kuvataan ontologioiden käyttäjäryhmien -- ontologioiden kehittäjien, tiedon annotoijien, tiedon hakijoiden ja semanttisen webin sovellusten kehittäjien -- tarpeita sekä esitellään ontologioiden hyödyntämiseen kehitettyjä sovelluksia. Yleisten ontologioiden käyttämiseen liittyvien toiminnallisuuksien tarjoamiseksi esitetään ontologiapalvelu ONKI, joka julkistettiin virallisesti käyttöön syyskuussa 2008.

Publishing information about upcoming events such as concerts and discussion group meetings in a structured format allows the event information to be aggregated, filtered and delivered to potential participants. Making automatic personalized recommendations about events requires structured metadata such as machine-understandable locations and semantic descriptions about the topic and audience of the event. We present a survey of the state of current semantic representation formats for events, including iCalendar and its RDFa and microformat representations, and show that their support for expressing rich structured metadata is limited. We have also tested how well different tools support and understand the formats. Based on the surveys we have implemented a rich event information schema for a health-oriented activity portal and developed an aggregation and validation tool for gathering and processing event information.

Providing citizens with reliable, up-to-date and individually relevant health information on the web is done by governmental, non-governmental, business and other organizations. Currently the information is published with little co-ordination and co-operation between the publishers. For publishers, this means duplicated work and costs due to publishing same information twice on many websites. Also maintaining links between websites requires work. From the citizens point of view, finding content is difficult due to e.g. differences in layman’s vocabularies compared to medical terminology and difficulties in aggregating information from several sites. To solve these problems, we propose as a solution a national scale semantic publishing system HealthFinland which consists of a 1) a centralized content infrastructure of health ontologies and services with tools, 2) a distributed semantic content creation channel based on several health organizations, and 3) an intelligent semantic portal aggregating and presenting the contents from intuitive and health promoting end-user perspectives for human users as well as for other web sites and portals.

The Semantic Web extends traditional web documents, i.e. the Web of Pages, with conceptual structures based on ontologies and metadata, i.e. the Web of Data. This paper presents a hybrid document search approach combining the benefits of the traditional text search of literal documents and the semantic search based on their underlying conceptual structures. The approach is based on document expansion, where documents are automatically annotated with not only the concepts explicitly present in a given document, but also with the ontologically related concepts using smaller weights. Our test results using the CLEF Test Suite suggest that document expansion alone achieves better recall than text search at the expense of precision. As a solution, a method of combining document expansion with text search is presented in which better recall was obtained without sacrificing precision. This approach seems promising when integrating unstructured, textual content with the Semantic Web of Data.

Authors and documents with identical titles are common in the digital library environment. In order to manage identities correctly, authority control is used by library and information scientists for disam- biguating and cross-referencing entity names. We argue that the benefits of traditional authority control can be enhanced by using techniques and technologies of the Semantic Web, leading to simpler management of multiple languages, better linkability of resources, simpler reuse of au- thority registries in applications, and less work in indexing. To demon- strate our propositions, we have created a prototype of an ontology server and service called ONKI People that is used in two ways: First, it is a centralized authority service providing human end-users with efficient and easy to use authority finding and disambiguation services based on faceted semantic search and visualizations. The services are available on- line also as AJAX and Web Services API for machines to use. Second, the underlying RDF triple store can be used as a content resource in ap- plications such as semantic cultural heritage portals. The paper discusses and demonstrates both use cases in a real life setting.

Ihminen tarvitsee kuluttajana ja yrittäjänä usein toisten ihmisten ja organisaatioden tukea palveluiden muodossa. Aiemmin tuntemattomien palveluiden löytäminen voi kuitenkin olla vaikeaa Internetin tiedon määrän lisääntyessä, koska tiedonhakijalle mielekäs sisältö hau­tautuu helposti epäolennaisen tiedon joukkoon. Tämän ongelman helpottamiseksi semantti­sen webin tekniikat tarjoavat uusia mahdollisuuksia. Tässä diplomityössä tutkittiin millaisia palveluiden haun kannalta hyödyllisiä ratkaisuja on aiemmin toteutettu. Tämän jälkeen nämä ratkaisut peilattiin kahden Internetissä sijaitsevan palvelun, PKT­-säätiön ylläpitämä Yrityksen palveluhakemisto ja Suomen Asiakastiedon ylläpitämä Aarre­palvelu, parannusehdotuksiksi. Tutkittuja palveluita ehdotettiin tässä diplomityössä parannettavan useilla erilaisilla tavoil­la. Näistä osalla ei ollut suoraan mitään tekemistä semanttisen webin tekniikoiden kanssa ja osa taas liittyi semanttiseen webiin hyvin kiinteästi. Erityisesti maantieteellisen tiedon käsittelyssä havaittiin olevan runsaasti kehitettävää molempien tutkittujen palveluiden koh­dalla. Myös eroja parannusehdotusten välillä oli havaittavissa. Johtuen Aarre­-palvelun suu­remmasta tietokannasta ja suuremmasta käyttäjäjoukosta siinä sanojen välisen verkon hyödyntäminen näytti olevan merkityksellisempää kuin Yrityksen palveluhakemiston koh­dalla.

Vocabularies are the building blocks of the Semantic Web providing shared terminological resources for content indexing, information retrieval, data exchange, and content integration. Most semantic web applications in practical use are based on lightweight ontologies and, more recently, on the Simple Knowledge Organization System (SKOS) data model being standardized by W3C. Easy and cost-efficient publication, integration, and utilization methods of vocabulary services are therefore highly important for the proliferation of the Semantic Web. This paper presents the ONKI SKOS Server for these tasks. Using ONKI SKOS, a SKOS vocabulary or a lightweight ontology can be published on the web as ready-to-use services in a matter of minutes. The services include not only a browser for human usage, but also Web Service and AJAX interfaces for concept finding, selecting and transporting resources from the ONKI SKOS Server to connected systems. Code generation services for AJAX and Web Service APIs are provided automatically, too. ONKI SKOS services are also used for semantic query expansion in information retrieval tasks. The idea of publishing ontologies as services is analogous to Google Maps. In our case, however, vocabulary services are provided and mashed-up in applications. ONKI SKOS was published in the beginning of 2008 and is to our knowledge the first generic SKOS server of its kind. The system has been used to publish and utilize some 60 vocabularies and ontologies in the National Finnish Ontology Service ONKI www.yso.fi.

Semantic web techniques can be used to relate two things together. However, usually this relation is not accompanied with a measure that would tell how interesting the relation is. Data mining tradition provides interestingness measures; it is natural to try and fit semantic web and data mining traditions together. In this paper we use support and confidence values provided by association rule mining as interestingness measures for relations. The presented method is tailored to location ontologies in order to find out what interesting mutual relations two places have based on annotations in the cultural heritage domain. The method also uses ontology-based reasoning to group places together. We present tests of running the method against a set of over 60,000 annotations in order to find out cultural heritage connections between places.

In this paper we present an ontology-based query expansion widget which utilizes the ontologies published in the ONKI Ontology Service. The widget can be integrated into a web page, e.g. a search system of a museum catalogue, enhancing the page by providing a query expansion functionality. We have tested the system with general, domain-specific and spatio-temporal ontologies.

This paper discusses problems of creating and using ontology library services in production use. One approach to a solution is presented with an online implementation--the Finnish Ontology Library Service ONKI--that is in pilot use on a national level in Finland. ONKI contributes to previous research on ontology libraries in many ways: First, mashup and web service support with various tools is provided for cost-efficient utilization of ontologies in indexing and search applications. Second, services covering the different phases of the ontology life cycle are provided. Third, the services are provided and used in real world applications on a national scale. Fourth, the ontology framework is being developed by a collaborative effort by organizations representing different application domains, such as health, culture, and business.

Ontologies aim to capture knowledge about things and their relationships. Publishing ontologies on the Semantic Web enables people and organizations to use shared ontologies in annotating e.g. photographs, videos, music, and other types of cultural objects. Search engines also use relationships provided by ontologies in semantic search, e.g. for query expansion or for view-based search. However, building ontologies is a time-consuming process, and it should be helped by automatic finding of interesting, possible relationships. Finding the correct concept for annotation purposes is helped by subsumption and partonomy hierarchies and associative relationships. In this paper we show how an analysis of co-occurrences of concepts in annotations can be used to provide interesting relationships for enriching ontological structures. We use association rule mining techniques and test the idea using a set of annotations of cultural objects in CULTURESAMPO portal and the Finnish General Upper Ontology YSO. The results are visualized in the ONKI SKOS browser to give an additional layer on top of the original relationships of the YSO ontology. An analysis shows that best ranked relationships should also be included in the ontology as subclassof or associative relationships.

Kulttuurisampo kokoaa suomalaisen kulttuurin palapeliä aivan uudella tavalla, kirjoittavat Eero Hyvönen ja Suvi Kettula

Artikkelissa luodaan katsaus kansallisessa Suomalaiset semanttisen webin ontologiat hankkeessa FinnONTO 2003-2007 ja FinnONTO 2.0 2008-2010 kehitettyihin paikkaontologioihin SUO (Suomalainen paikkaontologia) ja SAPO (Suomen ajallinen paikkaontologia), näiden julkaisemiseen AJAX-palveluina Kansallisessa ontologiapalvelussa ONKI, sekä paikkaontologioiden avulla Kulttuurisampo-portaaliin kehitettyihin palveluhin.

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.

Finding people is essential in finding information. Librarians and information scientists have studied authority control - psychologists and sociologists social networks. In aforementioned, authors link to documents (and co-authors) creating access points to information. In latter, social paths serve as channels for rumours as well as expertise. Key problems include identification and disambiguation of individuals followed by difficulties of tracking the social connections. With semantic web, these aspects can be approached simultaneously. In this paper, we define a simple ontology for describing people and organizations. The model is based on FOAF and other existing vocabularies. We also demonstrate search and visualization tools for finding people.

Thesauri and other controlled vocabularies act as building blocks of the Semantic Web by providing shared terminology for facilitating information retrieval, data exchange and integration. Representation and publishing methods are needed for utilizing thesauri efficiently, e.g., in content indexing and searching. W3C has provided the Simple Knowledge Organization System (SKOS) data model for expressing concept schemes, such as thesauri. A standard representation format for thesauri eliminates the need for implementing thesaurus specific rules or applications for processing them. However, there do not exist general tools which provide out of the box support for publishing and utilizing SKOS vocabularies in applications, without needing to implement application specific user interfaces for end users. For solving this problem the ONKI-SKOS server is presented.

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.

This article presents the vision and results of creating a national level cross-domain ontology service infrastructure in Finland in the FinnONTO project. The novelty of the infrastructure is based on two ideas. First, a system of open source core ontologies is being developed by transforming thesauri into mutually aligned lightweight ontologies, including a top ontology of 20,000 concepts that is extended by various domain specific ontologies. Second, the ONKI Ontology Server framework for publishing ontologies as ready to use services has been designed and implemented. ONKI provides legacy and other applications with ready to use functionalities for using ontologies on the user interface level as semantic widgets. The idea is to use ONKI for creating mash-up applications in a way analogous to using Google or Yahoo Maps, but in our case external applications are mashed-up with ontology support. The ontology framework presented is operational on the web and is being used in creating the application demonstrations.

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.

Content annotations in semantic cultural heritage portals commonly make spatiotemporal references to historical regions and places using names whose meanings are different in different times. For example, historical administrational regions such as countries, municipalities, and cities have been renamed, merged together, split into parts, and annexed or moved to and from other regions. Even if the names of the regions remain the same (e.g., “Germany”), the underlying regions and their relationships to other regions may change (e.g., the regional coverage of “Germany” at different times). As a result, representing and finding the right ontological meanings for historical geographical names on the semantic web creates severe problems both when annotating contents and during information retrieval. This paper presents a model for representing the meaning of changing geospatial resources. Our aim is to enable precise annotation with temporal geospatial resources and to enable semantic search and browsing using related names from other historical time periods. A simple model and metadata schema is presented for representing and maintaining geospatial changes from which an explicit time series of temporal part-of ontologies can be created automatically. The model has been applied successfully to representing the complete change history of municipalities in Finland during 1865–2007, and the resulting ontology time series is used in the semantic cultural heritage portal CULTURESAMPO to support faceted semantic search of contents and to visualizing historical regions on overlaying maps originating from different historical eras.

Geographic place names are semantically often highly ambiguous. For example, there are 491 places in Finland sharing the same name ”Isosaari” (great island) that are instances of several geographical classes, such as Island, Forest, Peninsula, Inhabited area, etc. Referencing unambiguously to a particular ”Isosaari”, either when annotating content or during information retrieval, can be quite problematic and requires usage of advanced search methods and maps for semantic disambiguation. Historical places introduce even more challenges, since historical metadata commonly make spatiotemporal references to historical regions and places using names whose meanings are non-existing or different in different times. This paper presents how these problems have been addressed in a large Finnish place ontology SUO and a historical geo-ontology SAPO. A location ontology server ONKI-Geo has been created for publishing the ontologies and utilizing them as mashup services. To demonstrate the usability of our ontologies, two case applications in the cultural heritage domain are presented.

The Semantic Web is based on using ontologies for enabling semantically disambiguated data exchange between distributed systems on the web. This requires efficient means for publishing ontologies on the web to ensure the availability, sharing and acceptance of the ontologies. Support services are needed for utilizing ontologies easily and cost-effectively in applications and legacy systems lacking ontology support. To address these vital needs, this paper presents the ONKI ontology service which provides ready-to-use mash-up functionalities, such as semantic disambiguation, concept finding and concept fetching as ready-to-use web widgets for adding ontology support to e.g. HTML forms using JavaScript. Two implementations of the ONKI Server are presented: ONKI-SKOS for ontologies presented in the Simple Knowledge Organization System (SKOS) language and ONKI-Geo for geographical ontologies with a map interface. The presented ONKI systems are operational on the web, used in the National Finnish Ontology Service. They have been successfully used in several pilot applications.

Semanttisen webin ideana on kuvailla tietoa siten, että koneet pystyvät ymmärtämään sitä, ja käyttämään älykkäitä tekniikoita tiedon hyödyntämiseksi. Tiedon kuvailemise käytetään ontologioita jotka muodostavat laajoja käsiteverkkoja. Kuvailua varten ontologiasta on läydettävä tarkimmin kohdetta kuvaavat käsitteet. Tässä työssä tutkittiin minkälaisia menetelmiä käsitteenvalintaan on kehitetty ja millä tavoin käsitteenvalintaa voidaan tukea visuaalisin keinoin. Lisäksi perehdyttiin joihinkin semanttisen webin sovelluksiin niiden käsitteenvalinnan osalta. Käsitevalitsimissa havaittiin puutteita liittyen käsitteiden merkityksen disambiguointiin ja siihen, kuinka helppoa niiden avulla on valita paras käsite kuvaamaan tietoa. Ongelmia oli myös tavoissa esittää useiden ontologioiden yhdistelmiä. Näiden havaintojen pohjalta suunniteltiin ja toteutettiin yleinen ja monentyyppisen aineiston käsittelyyn soveltuva käsitevalitsin IRMA

Tämä diplomityö käsittelee menetelmiä, joilla paikkatietoaineistoja muunnetaan ontologiseen muotoon sekä esittelee palvelun, ONKI-Paikan, jolla ontologisessa muodossa olevaa paikkatietoa voidaan tuottaa, ylläpitää ja hakea. Palvelu perustuu paikkatiedon mallintamiseen Suomalaisen paikkaontologian SUO:n mukaisesti. Työ koostuu neljästä vaiheesta. Ensimmäisessä vaiheessa selvitetään menetelmä, jolla SUO-ontologia populoidaan paikkainstansseilla. Erityistä huomiota kiinnitetään paikkojen uniikkien tunnisteiden, URI:en luomiseen. Toisessa vaiheessa selvitetään, miten ontologian populointivaiheessa tuotetut paikkojen RDF-kuvaukset on tallennettava. Kolmannessa vaiheessa ratkotaan ontologisessa muodossa olevan paikkatietoaineiston suuren määrän tuomia ongelmia muun muassa kehittämällä paikkatiedon RDF-varastolle indeksointitietokanta nopeita hakuja varten. Neljännessä vaiheessa kehitetään rajapinta hakujen suorittamista varten sekä hakurajapintaa hyödyntävä graafinen, selaimessa toimiva käyttöliittymä. Työ on tehty osana FinnONTO-projektia, jossa kehitettiin suomalaisiin olosuhteisiin räätälöityjä semanttisen webin ontologioita sekä näitä hyödyntäviä palveluita.

In this paper we examine 1) the scope of geo-ontologies used especially for the purposes of information retrieval on the Web, 2) the core geographical concepts and their mutual relations, and 3) the properties the concepts have. Furthermore, we present the Finnish geo-ontology (Suomalainen paikkaontologia, SUO) and discuss the theories and principles that have governed the development process, as well as the limitations and requirements the use of geographical dictionaries as an instance data source have imposed to the content and the structure of SUO.

Cultural heritage is by nature strongly interlinked, e.g. thematically and historically, but at the same time distributed in heterogeneous collections of different memory organizations at different locations. In order to provide the end-users with aggregated homogeneous views to distributed heterogeneous contents, semantic portals have been created successfully based on metadata and shared (or aligned) ontologies. This paper discusses two problems encountered in such a distributed semantic content creation environment. First, during the content creation work, how could a publisher start using shared ontologies in legacy cataloguing and annotation systems that do not support ontologies. Second, during content publication, how could a publisher re-use the aggregated content in its own legacy publication system, e.g., on the ordinary web pages of a museum or in a collection browser. As a solution, we present the ONKI Ontology Server for adding shared ontological annotation functionalities to legacy cataloguing systems in a practical, cost-efficient and lightweight way. For distributed publishing of the aggregated semantic portal services, we introduce the lightweight mash-up web widget components called floatlets . A major idea behind both the ONKI functionalities and floatlets is that they can be easily integrated with legacy systems on the user interface level, in the same spirit as e.g. Google Maps.

Informaation lisääntyessä yhteiskunnassa vaaditaan sen tehokasta käsittelyä yhä enemmän ammattilaisten lisäksi myös tavallisilta käyttäjiltä. Tällöin luonnollinen pyrkimys on yksinkertaistaa ja automatisoida tiedonhakuprosessia mahdollisimman paljon, johon semanttisen webin tekniikat tarjoavat uusia mahdollisuuksia. Tässä diplomityössä tutkittiin mahdollisuuksia dokumentin laajentamisen ja ontologisten käsitteiden hyödyntämisen kautta parantaa tiedonhakuprosessia tekstipohjaiseen aineistoon, kuten sanomalehtiarkistoon. Tätä tarkoitusta varten luotiin automaattinen annotointi ja hakusovellus Airo, joka suorittaa jonkin annetun ontologian pohjalta dokumentin laajennuksen. Tämä tapahtuu ontologisella käsiteklusteroinnilla, jossa jonkin käsitteen esiintyminen tekstissä nostaa myös ontologian hierarkiassa läheisten käsitteiden painoa kyseistä dokumenttia indeksoitaessa ja haettaessa. Järjestelmän testit osoittivat, että käsitehaku yhdistettynä sanahakuun laskee haun tarkkuutta, mutta nostaa saantia. Sen sijaan hybridimenetelmä dokumentin- ja kyselyn laajennuksesta, jossa perinteisen sanahaun tuottamien dokumenttien käsitteillä suoritetaan laajentava haku, nosti saantia tarkkuuden kärsimättä. Luotu järjestelmä on ontologiariippumaton ja jokaisen ontologian tuottamat käsitteistykset talletetaan omaan indeksiinsä, jolloin niitä voidaan hakea erikseen.

Tiedonhakuun webissä on kehitetty sanahaun lisäksi rikkaampia tiedonhaku- ja selausmenetelmiä, jotka mahdollistavat tutkivan tiedonhaun. Niistä on hyötyä silloin, kun käyttäjä ei etukäteen tiedä täsmälleen, mitä hän on etsimässä. Yksi tällainen hakukäyttöliittymätyyppi on moninäkymähaku, jossa haun kohteena oleva tietosisältö luokitellaan moniulotteiseksi avaruudeksi fasettiluokituksen periaattein. Käyttöliittymä mahdollistaa aineiston haun ja selaamisen minkä tahansa ulottuvuuden tai niiden yhdistelmän suhteen. Moninäkymähaun kehitys lähti liikkeelle käyttöliittymätutkimuksen piiristä. Moninäkymähakuun perustuvia käyttöliittymiä käytettiin myöhemmin semanttisen webin sovelluksissa ja portaaleissa, joissa kuitenkaan ei samassa määrin huomioitu käyttäjiä suunnitteluprosessin aikana. Tutkielmassa käyttäjäkeskeisiä suunnittelu- ja tiedonjäsennysmenetelmiä sovellettiin terveysaiheista materiaalia sisältävän tervesuomi.fi-portaalin suunnitteluun sekä toteutettiin moninäkymähakua käyttävä portaalin prototyyppi semanttisen webin teknologioiden avulla. Portaalin informaatioarkkitehtuuri suunniteltiin korttienjärjestämismenetelmän avulla ja sen käyttöliittymä rakennettiin käyttäjäkeskeisellä suunnittelu- ja arviointiprosessilla. Tulosten arviointi osoittaa, että käyttäjäkeskeisistä menetelmistä oli merkittävää hyötyä portaalin suunnittelussa. Valmiin prototyypin käytettävyyden arviointi osoitti, että portaalin käytettävyys on käyttäjäkeskeisten suunnittelu- ja arviointimenetelmien ansiosta saatu hyvälle tasolle. Arviointi myös paljasti portaalin aineistoissa, käyttöliittymässä ja tiedon jäsennystavassa ongelmia, joihin terveysportaalin jatkokehityksessä voidaan puuttua.

Diplomityön tavoitteena on tutkia semanttisen webin tarjoamia mahdollisuuksia tiedonhaussa. Tähän tavoitteeseen pyrin toteuttamalla tiedonhakujärjestelmän, jossa lukuisista eri museoista peräisin olevat heterogeeniset aineistot ovat haettavissa yhdellä käyttöliittymällä. Työni kirjallisuusosassa käsittelen tiedonhaun teoriaa, metadatan käyttöä ja semanttisen webin toimintaperiaatteita. Kirjallisuusosan yhteydessä paneudun tutkimusryhmässä aikaisemmin tehtyyn tutkimukseen erityisesti sisällönkuvailun ja moninäkymähaun osalta. Työssäni kehitin heterogeenisen aineiston yhdistämisen mahdollistavaa toimintakeskeistä sisällönkuvailun menetelmää ja tietomallia. Mallin varaan toteutin moninäkymähaun periaatteella toimivan tiedonhakujärjestelmän, jolla toimintakeskeisesti kuvailtua aineistoa voidaan hakea. Saadakseni tarkkaa tietoa tiedonhakujärjestelmän toimivuudesta ja soveltuvuudesta suunniteltuun käyttötarkoitukseen, evaluoin valmista tiedonhakujärjestelmää käyttäjäkeskeisen evaluointimallin mukaisesti. Evaluointia varten suunnittelin kokeen, johon kuuluivat hakutehtävät ja tiedon keruun menetelmät, kuten kyselylomakkeet, transaktioloki sekä videokuvan ja äänen kaappaus. Toimintakeskeinen tietomalli osoittautui tiedonhakujärjestelmän sovelluskehityksen aikana toimivaksi ja heterogeenisiä aineistoja yhdistäväksi tietomalliksi. Työssä kehittämäni toimintakeskeinen semanttinen moninäkymähaku sekä aineiston kartta- ja aikajanaprojisointi toimivat täysin toimintakuvausten ja temaattisten roolien varassa. Käyttäjätestit puolestaan todistivat tiedonhakujärjestelmän toimivaksi. Hakujärjestelmä tuki jokaista tehtävätyyppiä ja käyttäjät pitivät arvioissaan järjestelmää uudentyyppisenä, tehokkaana, toimivana ja hyödyllisenä. Vaikka käyttöliittymä tarjosi perinteisen vapaatekstihaun, käytettiin toimintakeskeistä semanttista moninäkymähakua jokaisen tehtävätyypin suorituksen yhteydessä. Käyttäjät olivat melko tyytyväisiä hakujärjestelmän palauttamien dokumenttien relevanssiin. Kartta- ja aikajanaprojektioita pidettiin innovatiivisina ja toimivina lisäominaisuuksina. Käyttäjätestien aikana kritisoitiin moninäkymähaun käytön vaikeutta ja näkymien sisältöä pidettiin vaikeasti ymmärrettävänä. On selvää, että moninäkymähakua on edelleen kehitettävä. Evaluoinnin tulosten perusteella näyttää siltä, että moninäkymähaku ja vapaatekstihaku soveltuvat erityyppisten tehtävien suorittamiseen ja ovat näin ollen toisiaan täydentäviä hakutapoja. Moninäkymähakua hyödynnettiin tehtävissä, joissa lähtötiedot eivät olleet tarkkoja. Tehtävissä, joissa tehtävänannossa annettiin tarkkaa metatietoa, oli tekstihaku hyödyllisempi.

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.

We argue that an ontology of historical events is needed in semantic portals for cultural heritage due to three reasons. First, ontological identifiers (URIs) of events, such as the World War II or coronation of Napoleon, are needed in order to make collection metadata mutually interoperable in terms of related events---in the vein as identifiers are needed for identifying artifact types, persons, and geolocations when annotating collection items. Second, events are of central importance in creating semantic links between cultural contents in applications such as recommendation systems. Third, historical events are important as content items of their own, forming the backbone of chronological histories.

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.

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.

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.

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.

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.

This paper presents a method for making metadata conforming to heterogeneous schemas semantically interoperable. The idea is to make the knowledge embedded in the schema structures interoperable and explicit by transforming the schemas into a shared, event-based representation of knowledge about the real world. This enables and simplifies accurate reasoning services such as cross-domain semantic search, browsing, and recommending. A case study of transforming three different schemas and datasets is presented. An implemented knowledge-based recommender system utilizing the results in the semantic portal \CS\ was found useful in a preliminary user study.

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.

Geographic place names are widely used but are semantically often highly ambiguous. For example, there are 491 places in Finland sharing the same name Isosaari (great island) that are instances of several geographical classes, such as Island, Forest, Peninsula, Inhabited area, etc. Referencing unambiguously to a particular Isosaari , either when annotating content or during information retrieval, can be quite problematic and requires usage of advanced search methods and maps for semantic disambiguation. This paper presents an ontology server, ONKI-Paikka, for solving the place finding and place name disambiguation problem. In ONKI-Paikka, places can be found by a faceted search engine, combined with semantic autocompletion and a map service for constraining search and for visualizing results. The service can be connected to legacy applications cost-effectively by using Ajax-technology in the same spirit as Google Maps that is used in ONKI-Paikka as a subservice.

This paper shows how semantic web techniques can be applied to solving problems of distributed content creation, discovery, linking, aggregation, and reuse in health information portals, both from end-users and content publishers viewpoints. As a case study, the national semantic health portal \HF\ is presented. It provides citizens with intelligent searching and browsing services to reliable and up-to-date health information created by various health organizations in Finland. The system is based on a shared semantic metadata schema, ontologies, and ontology services. The content includes metadata about thousands of web documents such as web pages, articles, reports, campaign information, news, services, and other information related to health.

The Semantic Web is based on using shared ontologies for enabling semantically disambiguated data exchange between distributed systems on the web. This requires, from the ontology publisher s viewpoint, efficient means for publishing ontologies on the web to ensure the availability and acceptance of the ontologies. From the ontology user s viewpoint, support services are needed for utilizing ontologies easily and cost-effectively in the users own systems that are typically legacy systems without ontology support. This paper presents the ONKI ontology server for addressing these vital needs. For the publisher, ONKI provides a server and a Simple Knowledge Organization (SKOS) compatible light-weight ontology browser with ready-made web interfaces for making ontologies available both for human and machine users. For external legacy and other applications, ONKI provides centralized ontology services for semantic disambiguation, concept finding, and concept fetching. A major contribution of ONKI is to provide these services as ready-to-use functionalities for creating mash-up applications very cost-efficiently. Two prototypes of the system---ONKI-SKOS for all kinds of ontologies and ONKI-Geo for geographical ontologies with a map mash-up interface---are operational on the web and are currently being successfully used in several pilot applications.

This paper presents a system for searching semantic relations between web resources, in our case significant persons of art history. The system is based on the Union List of Artists Names (ULAN) metadata of some 120,000 persons and organizations.

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.

Semanttisen Webin perustavana ajatuksena on tuoda Internetiin – tai suppeammassa mielessä hyperlinkitettyyn aineistoon – järjestystä määrittelemällä eksplisiittisiä, koneluettavia käsitteistöjä ja kuvaamalla Internetin sisältämää aineistoa tällä käsitteistöllä. Nämä kaksi työvaihetta kuuluvat keskeisesti Semanttisen Webin ydinalueisiin. Tässä tutkielmassa määritellään Semanttisen Webin liittyvän aineiston kuvailun eli ontologiaperustaisen annotoinnin piirteitä ja toisaalta myös rajoja. Ontologiaperustainen annotointi on aineiston kuvailua, jonka määrittävänä piirteenä on tietomalli. Annotoinnin automatisointi on keskeinen haaste ontologiaperustaisten järjestelmien tuottamisessa, sillä manuaalisesti tehtävä annotointi on yleensä hidasta ja aikaa vievää. Automaattista annotointia edustavien järjestelmien joukko on kirjava, eikä täsmällistä määrittelyä automaattisen annotoinnin ongelmakentästä esiinny kirjallisuudessa. Työssä määritellään automaattisille annotointijärjestelmille malli, jonka avulla voidaan vertailla järjestelmiä toisiinsa ja mallintaa uusia. Mallia sovelletaan työssä ontologiaperustaisten järjestelmien vertailuun ja automaattisen annotointijärjestelmän Pokan, toteuttamisessa.

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.

Paikannimiä käytetään monissa arkistoissa, museoissa ja tietokannoissa ainoana paikka-tietona. Paikannimistössä ja rajoissa tapahtuu kuitenkin ajan kuluessa muutoksia. Valtioiden rajat muuttuvat, läänien ja maakuntien alueita määritetään uudestaan ja kunnat jakaantuvat tai yhdistyvät toisiinsa tai vaihtavat nimeään. Tietojen hakeminen tämäntyyppisistä kohteista on tuottanut puutteellisia tai virheellisiä tuloksia, ellei hakijalla ole ollut tietoa tapahtuneista aluemuutoksista. Insinöörityön tavoitteena on löytää keinoja hallita ajallisesti muuttuvaa paikkatietoa niin, että tietoihin tehtävien hakujen tarkkuus paranee.Insinöörityöraportissa kuvataan erityyppiset muutokset, joita Suomen kunnissa on niiden olemassaolon aikana tapahtunut. Erilaiset muutokset luokitellaan seitsemään tyyppiin, jotka ovat perustaminen, yhdistyminen, jakaantuminen, nimenmuutos, aluesaanti toisesta maasta ja alueluovutus toiselle maalle ja aluesiirto kahden kunnan välillä. Samaa jakoa voidaan käyttää myös muissa hallinnollisissa alueissa tapahtuneisiin muutoksiin. Kuntien välisten muutosten tietoja käytettiin Geologian tutkimuskeskuksen (GTK) valokuvatietokannassa. Tietokanta toteutettiin Imatch-ohjelman avulla. Kuvat voidaan tietokannassa merkitä siihen kuntaan, jossa ne on kuvattu, mutta kuvia voidaan hakea myös ajallisesti myöhemmän kuntajaon perusteella. Eri aikoina olleita kuntia kuvaavien kuntakategorioiden väliset yhteydet toteutettiin yhdistävien ja poissulkevien loogisten operaattoreiden avulla.Kuntamuutostietoja käytettiin myös valmistettaessa Suomen ajallista paikkaontologiaa osana FinnONTO-projektia. Työssä kuvataan ontologioiden valmistuksen perusteet ja SAPO-ontologian valmistuksessa käytetyt menetelmät, mm. ontologiaversioiden väliset muutossillat ja sijainnin todennäköisyyden laskevan päättelykoneen periaate. Suomen ajallinen ontologia tulee vapaaseen käyttöön ONKI-ontologiakirjaston kautta, ja ensimmäisenä sitä käytetään FinnONTO-projektin semanttisen webin tekniikoita esittelevässä KulttuuriSampo-portaalissa.Alustavien kokeiden perusteella paikkatiedon ajallisten muutosten huomioonottaminen parantaa selvästi hakujen osuvuutta sekä GTK:n valokuvatietokannassa että paljon historiallista aineistoa sisältävässä KulttuuriSampo-portaalissa. Näin ollen näiden uusien ajallisen paikkatiedon hallintaan soveltuvien menetelmien käyttöönottoa voidaan suositella kaikkeen paikannimistön perusteella tapahtuvaan tiedon annotointiin eli nimeämiseen ja hakuun.

Creation of rich, ontology-based metadata is one of the major challenges in developing the Semantic Web. Emerging applications utilizing semantic web techniques, such as semantic portals, cannot be realized if there are no proper tools to provide metadata for them. This paper discusses how to make provision of metadata easier and cost-effective by an annotation framework comprising of annotation editor combined with shared ontology services. We have developed an annotation system supporting distributed collaboration in creating annotations, and hiding the complexity of the annotation schema and the domain ontologies from the annotators. Our system adapts flexibly to different metadata schemas, which makes it suitable for different applications. Support for using ontologies is based on ontology services, such as concept searching and browsing, concept URI fetching, semantic autocompletion and linguistic concept extraction. The system is being tested in various practical semantic portal projects.

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.

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.

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.

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.

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.