The generation of e-learning exercise problems from subject ontologies

The teaching/ learning of cognitive skills, such as problem-solving, is an important goal in most forms of education. In well-structured subject areas certain exercise problem types may be precisely described by means of machine-processable knowledge structures or ontologies. These ontologies can readily be used to generate individual problem examples for the student, where each problem consists of a question and its solution. An example is given from the subject domain of computer databases

Semantic technology for management of data recorded during therapy of cardiac arrest patients

Master's thesis in Computer scienceThe topic of this thesis is the integration of data recorded during cardiopulmonary resuscitation (CPR). In the process of CPR many important data should be recorded, such as: time of the cardiac arrest witnessed, number of shocks given to the patient and parameters for each shock. These data will be used for the coming analysis and producing the report of the therapy. The analysis and comparison of the CPR data and reports may improve the survival rate. However the formats and terminologies of CPR data vary greatly between EMS (Emergency Medical Services) systems in different places. So it is inconvenient to access, compare and transfer data between different EMS systems. In this thesis we use semantic way to solve the heterogeneity problem. An ontology is defined to provide a standardized representation of the heterogeneous data from different EMSs. In this ontology we defined standardized CPR terminologies and report style, and the “dialect” from different EMS systems can be mapped onto this ontology. An interface is defined to map the different databases from different EMS systems onto this ontology. And we provide a uniform way based on the ontology to query all of the databases as if they are one huge database

A survey of RDB to RDF translation approaches and tools

ISRN I3S/RR 2013-04-FR 24 pagesRelational databases scattered over the web are generally opaque to regular web crawling tools. To address this concern, many RDB-to-RDF approaches have been proposed over the last years. In this paper, we propose a detailed review of seventeen RDB-to-RDF initiatives, considering end-to-end projects that delivered operational tools. The different tools are classified along three major axes: mapping description language, mapping implementation and data retrieval method. We analyse the motivations, commonalities and differences between existing approaches. The expressiveness of existing mapping languages is not always sufficient to produce semantically rich data and make it usable, interoperable and linkable. We therefore briefly present various strategies investigated in the literature to produce additional knowledge. Finally, we show that R2RML, the W3C recommendation for describing RDB to RDF mappings, may not apply to all needs in the wide scope of RDB to RDF translation applications, leaving space for future extensions

Relational Database information availability to Semantic Web technologies

Thesis is about possible ways to connect semantic web technologies and relational databases. RDB2OWL language is developed that enable to define mappings between elements of OWL ontology and relational database schema in a concise and human readable form. The language is aimed to get ontology class instances and property values from relational database data, e.g, to generate RDF from relational table data. Promocijas darbā apskatītas Semantiskā tīmekļa tehnoloģiju un relāciju datu bāzu sasaistes iespējas. Izstrādāta valoda RDB2OWL, kas ļauj īsi un cilvēkam lasāmā formā nodibināt atbilstību starp OWL ontoloģijas un relāciju datu bāzes shēmas elementiem ar mērķi iegūt ontoloģijas klašu instances un īpašību vērtības no relāciju datiem, t.i., iegūt RDF trijniekus no tabulu rakstiem.This work has been supported by the European Social Fund within the project «Support for Doctoral Studies at University of Latvia

Relāciju datu bāzu informācijas pieejamība semantiskā tīmekļa tehnoloģijām

Promocijas darba „Relāciju datu bāzu informācijas pieejamība semantiskā tīmekļa tehnoloģijām” Anotācija Atslēgas vārdi: relāciju datu bāze, RDF, OWL, ontoloģijas, attēlojums Semantiskā tīmekļa uzdevums ir pārvērst tīmekli no milzīgas dokumentu kolekcijas par bagātu datu avotu, no kura datorprogrammas varētu automātiski iegūt informāciju. Lielākā daļa esošo datu glabājas relāciju datu bāzēs un nav pieejamas semantiskam tīmeklim. Darba mērķis ir atrast risinājumu relāciju datu bāzu un OWL ontololoģijas sasaistei. Darbā 1) pētīti esošie risinājumus relāciju datu bāzu un RDF/OWL ontoloģiju sasaistes nodrošināšanā; 2) izveidota RDB-RDF/OWL attēlojuma specificēšanas valoda, kas orientēta uz lasāmību, pieraksta īsumu un augsta līmeņa konstrukciju izmantošanu; 3) izveidota praktiskām situācijām piemērota efektīva atbilstību realizācija, izmantojot relāciju datu bāzi atbilstību informācijas glabāšanai un RDF trijnieku ģenerēšanai, un tā pielietota Latvijas medicīnas 6 reģistru datu semantiskā reinženierijā.Thesis „Relational Database information availability to Semantic Web technologies” Annotation Keywords: Relational databases, RDF, OWL, ontologies, mapping The purpose of Semantic Web is to convert the web from huge collection of documents into rich dataset from which it would be possible for computer programs to get information automatically. Most of real data are stored in relational databases and are not available to Semantic Web. The purpose of this work is to find solution to map relational databases and OWL ontologies. In the thesis 1) existing RDB-to-RDF/OWL mapping solutions are investigated; 2) RDB-to-RDF/OWL mapping specification language is designed that is oriented towards readability, conciseness and high level construct usage; 3) effective and suitable for practical use-cases mapping implementation is created using relational database for mapping data storage and RDF triple generation; the implementation was applied to semantic re-engineering of 6 Latvian Medicine registries

Configuração e interrogação com sistemas federados

Apesar da existência de produtos comerciais e da investigação na área, a construção de sistemas de informação com diversos componentes distribuídos, heterogéneos e autónomos - conhecidos como sistemas de informação federados - é ainda um desafio. Estes sistemas de informação oferecem uma visão global unificada sobre os vários modelos de dados (parciais). No entanto, a modelação destes sistemas é um desafio, já que modelos de dados como o relacional não incluem informação sobre a distribuição e tratamento de heterogeneidade. É também necessário interagir com estes sistemas de informação, através de interrogações sobre os diversos componentes dos sistemas, sem ser necessário conhecer os detalhes dos mesmos. Este trabalho propõe uma abordagem a estes desafios, através da utilização de modelos para descrição semântica, e.g. linguagem OWL (Ontology Web Language), para construir uma descrição unificada dos seus diversos modelos parciais. O modelo criado para dar suporte a esta descrição é, em parte, baseado em ontologias existentes, que foram alteradas e extendidas para resolver diversos desafios de modelação. Sobre este modelo, é criado um componente de software que permite a execução de interrogações SQL (Structured Query Language) sobre o sistema federado, resolvendo os problemas de distribuição e heterogeneidade existentes

A survey of RDB to RDF translation approaches and tools

ISRN I3S/RR 2013-04-FR 24 pagesRelational databases scattered over the web are generally opaque to regular web crawling tools. To address this concern, many RDB-to-RDF approaches have been proposed over the last years. In this paper, we propose a detailed review of seventeen RDB-to-RDF initiatives, considering end-to-end projects that delivered operational tools. The different tools are classified along three major axes: mapping description language, mapping implementation and data retrieval method. We analyse the motivations, commonalities and differences between existing approaches. The expressiveness of existing mapping languages is not always sufficient to produce semantically rich data and make it usable, interoperable and linkable. We therefore briefly present various strategies investigated in the literature to produce additional knowledge. Finally, we show that R2RML, the W3C recommendation for describing RDB to RDF mappings, may not apply to all needs in the wide scope of RDB to RDF translation applications, leaving space for future extensions

Template Based Semantic Integration: From Legacy Archaeological Datasets to Linked Data

The online dissemination of datasets to accompany site monographs and summary documentation is becoming common practice within the archaeology domain. Since the legacy database schemas involved are often created on a per-site basis, cross searching or reusing this data remains difficult. Employing an integrating ontology, such as the CIDOC CRM, is one step towards resolving these issues. However, this has tended to require computing specialists with detailed knowledge of the ontologies involved. Results are presented from a collaborative project between computer scientists and archaeologists that provided light weight tools to make it easier for non-specialists to publish Linked Data. Applications developed for the STELLAR project were applied by archaeologists to major excavation datasets and the resulting output was published as Linked Data, conforming to the CIDOC CRM ontology. The template-based Extract Transform Load method is described. Reflections on the experience of using the template-based tools are discussed, together with practical issues including the need for terminology alignment and licensing consideration

Contaminant Hydrogeology Knowledge Base (CHKb) of Georgia, USA

Hydrogeologists collect data through studies that originate from a diverse and growing set of instruments that measure, for example, geochemical constituents of surface and groundwater. Databases store and publish the collected data on the Web, and the volume of data is quickly increasing, which makes accessing data problematic and time consuming for individuals. One way to overcome this problem is to develop ontology to formally and explicitly represent the domain (e.g., contaminant hydrogeology) knowledge. Using OWL and RDF, contaminant hydrogeology ontology (CHO) is developed to manage hydrological spatial data for Georgia, USA. CHO is a conceptual computer model for the contaminant hydrogeology domain in which concepts (e.g. contaminant, aquifer) and their relationships (e.g. pollutes) are formerly and explicitly defined. Cyberinfrastructure for exposing CHO and datasets (i.e., CHKb) as Linked Data on the Web is developed. Cyberinfrastructure consists of storing, managing, querying, and visualizing CHKb that can be accessed from URL: cho.gsu.edu