scholarly journals New definition of the SPARQL — query language for the Semantic Web

2018 ◽  
pp. 19-31 ◽  
Author(s):  
A.F. Kurgaev ◽  
Keyword(s):  
Semantic Web ◽  
Query Language ◽  
Sparql Query ◽  
Definition Of

scholarly journals Using superimposed multidimensional schemas and OLAP patterns for RDF data analysis

2018 ◽  
Vol 8 (1) ◽  
pp. 18-37 ◽  
Author(s):  
Median Hilal ◽  
Christoph G. Schuetz ◽  
Michael Schrefl
Keyword(s):  
Data Analysis ◽  
Semantic Web ◽  
Query Language ◽  
Query Languages ◽  
Sparql Query ◽  
Semantic Web Technologies ◽  
Rdf Data ◽  
Self Service ◽  
Description Framework ◽  
Definition Of

Abstract The foundations for traditional data analysis are Online Analytical Processing (OLAP) systems that operate on multidimensional (MD) data. The Resource Description Framework (RDF) serves as the foundation for the publication of a growing amount of semantic web data still largely untapped by companies for data analysis. Most RDF data sources, however, do not correspond to the MD modeling paradigm and, as a consequence, elude traditional OLAP. The complexity of RDF data in terms of structure, semantics, and query languages renders RDF data analysis challenging for a typical analyst not familiar with the underlying data model or the SPARQL query language. Hence, conducting RDF data analysis is not a straightforward task. We propose an approach for the definition of superimposed MD schemas over arbitrary RDF datasets and show how to represent the superimposed MD schemas using well-known semantic web technologies. On top of that, we introduce OLAP patterns for RDF data analysis, which are recurring, domain-independent elements of data analysis. Analysts may compose queries by instantiating a pattern using only the MD concepts and business terms. Upon pattern instantiation, the corresponding SPARQL query over the source data can be automatically generated, sparing analysts from technical details and fostering self-service capabilities.

scholarly journals Creating RESTful APIs over SPARQL endpoints using RAMOSE

Semantic Web ◽  
2021 ◽  
pp. 1-19
Author(s):  
Marilena Daquino ◽  
Ivan Heibi ◽  
Silvio Peroni ◽  
David Shotton
Keyword(s):  
Semantic Web ◽  
Service Providers ◽  
Query Language ◽  
Sparql Query ◽  
Direct Access ◽  
Technical Solution ◽  
Semantic Web Technologies ◽  
Web Technologies ◽  
Sparql Endpoint ◽  
Rdf Data

Semantic Web technologies are widely used for storing RDF data and making them available on the Web through SPARQL endpoints, queryable using the SPARQL query language. While the use of SPARQL endpoints is strongly supported by Semantic Web experts, it hinders broader use of RDF data by common Web users, engineers and developers unfamiliar with Semantic Web technologies, who normally rely on Web RESTful APIs for querying Web-available data and creating applications over them. To solve this problem, we have developed RAMOSE, a generic tool developed in Python to create REST APIs over SPARQL endpoints. Through the creation of source-specific textual configuration files, RAMOSE enables the querying of SPARQL endpoints via simple Web RESTful API calls that return either JSON or CSV-formatted data, thus hiding all the intrinsic complexities of SPARQL and RDF from common Web users. We provide evidence that the use of RAMOSE to provide REST API access to RDF data within OpenCitations triplestores is beneficial in terms of the number of queries made by external users of such RDF data using the RAMOSE API, compared with the direct access via the SPARQL endpoint. Our findings show the importance for suppliers of RDF data of having an alternative API access service, which enables its use by those with no (or little) experience in Semantic Web technologies and the SPARQL query language. RAMOSE can be used both to query any SPARQL endpoint and to query any other Web API, and thus it represents an easy generic technical solution for service providers who wish to create an API service to access Linked Data stored as RDF in a triplestore.

scholarly journals Question Answering System over Linked Data: A Detailed Survey

2020 ◽  
Vol 8 (1) ◽  
pp. 32-47
Author(s):  
G. M. Rasiqul Islam Rasiq ◽  
Abdullah Al Sefat ◽  
Tanjila Hossain ◽  
Md. Israt-E-Hasan Munna ◽  
Jubayeath Jahan Jisha ◽  
...  
Keyword(s):  
Semantic Web ◽  
Linked Data ◽  
Question Answering ◽  
Query Language ◽  
Sparql Query ◽  
Amount Of Information ◽  
Advantages And Disadvantages ◽  
Detailed Survey ◽  
The World ◽  
Basic Understanding

As the amount of information in the world is growing very quickly, in the case of the semantic web this increasing amount of information is becoming more difficult to find and manage the exact answers to our various questions. To overcome these difficulties some systems have been developed that make it work for us. But there exists many challenges in developing these systems that require a lot of improvement. In this tutorial, we give a basic understanding of Semantic web, RDF triple, SPARQL query language. Here we will discuss the main obstacles for the QA system in processing the questions and a detailed survey of the existing systems. We also provide some advantages and disadvantages of existing QA systems. We also discuss the evaluation campaigns of the existing models based on their precision, recall and F-1 scores on the QALD dataset.  

scholarly journals Petri nets on the semantic web guidelines and infrastructure

2004 ◽  
Vol 1 (2) ◽  
pp. 127-151 ◽  
Author(s):  
Dragan Gasevic
Keyword(s):  
Semantic Web ◽  
Petri Net ◽  
Ontology Language ◽  
Uml Profiles ◽  
Community Effort ◽  
Model Sharing ◽  
Petri Net Markup Language ◽  
Description Framework ◽  
Definition Of ◽  
Resource Description

This paper gives the Petri net ontology as the most important element in providing Petri net support for the Semantic Web. Available Petri net formal descriptions are: metamodels, UML profiles, ontologies and syntax. Metamodels are useful, but their main purpose is for Petri net tools. Although the current Petri-net community effort Petri Net Markup Language (PNML) is XML-based, it lacks a precise definition of semantics. Existing Petri net ontologies are partial solutions specialized for a specific problem. In order to show current Petri net model sharing features we use P3 tool that uses PNML/XSLT-based approach for model sharing. This paper suggests developing the Petri net ontology to represent semantics appropriately. This Petri net ontology is described using UML, Resource Description Framework (Schema) RDF(S) and the Web Ontology Language-OWL.

The Utilization of Semantic Web for Integrating Enterprise Systems

2008 ◽  
pp. 97-114
Author(s):  
Dimitrios Tektonidis ◽  
Albert Bokma
Keyword(s):  
Semantic Web ◽  
Heterogeneous Systems ◽  
Enterprise Application Integration ◽  
Application Integration ◽  
Semantic Web Technologies ◽  
Web Technologies ◽  
Enterprise Application ◽  
Shared Information ◽  
Service Oriented ◽  
Definition Of

Integrating enterprise system has become an issue of sharing information rather than transforming information due to the increasing complexity and the heterogeneity of the applications. The transition from application centric to integration centric enterprise application integration (EAI) requires methods and technologies that will enable and facilitate the definition of shared information. The use of ontologies Semantic Web and technologies can improve the existing EAI methods by providing a framework capable to define shared information. Ontologies based Enterprise application integration (ONAR) framework utilizes Semantic Web technologies to define shared information among heterogeneous systems. The present paper presents the utilization of ontologies for the formation of ONAR framework and its application for service oriented application integration (SOAI)

Ontologies in the Health Field

2011 ◽  
pp. 37-56 ◽  
Author(s):  
Michel Simonet ◽  
Radja Messai ◽  
Gayo Diallo
Keyword(s):  
Data Mining ◽  
Information Retrieval ◽  
Semantic Web ◽  
Knowledge Bases ◽  
Health Data ◽  
Efficient Manner ◽  
Common Definition ◽  
Ontology Design ◽  
Definition Of ◽  
Health Field

Health data and knowledge had been structured through medical classifications and taxonomies long before ontologies had acquired their pivot status of the Semantic Web. Although there is no consensus on a common definition of an ontology, it is necessary to understand their main features to be able to use them in a pertinent and efficient manner for data mining purposes. This chapter introduces the basic notions about ontologies, presents a survey of their use in medicine and explores some related issues: knowledge bases, terminology, and information retrieval. It also addresses the issues of ontology design, ontology representation, and the possible interaction between data mining and ontologies.

Constraint-Based Multi-Dimensional Databases

2009 ◽  
pp. 961-986
Author(s):  
Franck Ravat ◽  
Olivier Teste ◽  
Gilles Zurfluh
Keyword(s):  
Graphical Representation ◽  
Query Language ◽  
Computer Scientist ◽  
Data Querying ◽  
Definition Of ◽  
Multidimensional Modelling ◽  
Graphical Query Language ◽  
Drill Down

This chapter deals with constraint-based multidimensional modelling. The model we define integrates a constellation of facts and dimensions. Along each dimension, various hierarchies are possibly defined and the model supports multiple instantiations of dimensions. The main contribution is the definition of intra-dimension constraints between hierarchies of a same dimension as well as inter-dimension constraints of various dimensions. To facilitate data querying, we define a multi-dimensional query algebra, which integrates the main multi-dimensional operators such as rotations, drill down, roll up… These operators support the constraint-based multi-dimensional modelling. Finally, we present two implementations of this algebra. First, OLAP-SQL is a textual language integrating multi-dimensional concepts (fact, dimension, hierarchy), but it is based on classical SQL syntax. This language is dedicated to specialists such as multi-dimensional database administrators. Second, a graphical query language is presented. This language consists in a graphical representation of multi-dimensional databases, and users specify directly their queries over this graph. This approach is dedicated to non-computer scientist users.

Semantic Web and Digital Libraries

2011 ◽  
pp. 271-285
Author(s):  
Giorgio Poletti
Keyword(s):  
Semantic Web ◽  
Data Warehouse ◽  
Digital Library ◽  
Digital Libraries ◽  
Knowledge Society ◽  
Specialized Software ◽  
Close Relationship ◽  
Definition Of ◽  
Access To Documents ◽  
The Web

An analysis of the reality surrounding us clearly reveals the great amount of information, available in different forms and through different media. Volumes of information available in real time and via the Web are concepts perceived as closely related. This perception is supported by the remark that the objective of the Web was the definition and construction of a universal archive, a virtual site in which the access to documents was possible with no limits of time or space. In this digital library, documents have to be equipped with logical connections making possible for each user the definition of a reading map that expands according to the demand for knowledge gradually built up. This perspective is pointing now in the direction of the Semantic Web, a network satisfying our requests while understanding them, not by some magic telepathic communication between browser and navigator, but rather a data warehouse in which documents are matched to meta-data,1 letting specialized software to distinguish fields, importance, and correlation between documents. Semantic Web and library terms have an ever increasing close relationship, fundamental for the progress and the didactic efficiency in knowledge society.

Constraint-Based Multi-Dimensional Databases

2011 ◽  
pp. 323-360 ◽  
Author(s):  
Franck Ravat ◽  
Olivier Teste ◽  
Gilles Zurfluh
Keyword(s):  
Graphical Representation ◽  
Query Language ◽  
Computer Scientist ◽  
Data Querying ◽  
Definition Of ◽  
Graphical Query Language ◽  
Drill Down

This chapter deals with constraint-based multi-dimensional modelling. The model we define integrates a constellation of facts and dimensions. Along each dimension, various hierarchies are possibly defined and the model supports multiple instantiations of dimensions. The main contribution is the definition of intra-dimension constraints between hierarchies of a same dimension as well as inter-dimension constraints of various dimensions. To facilitate data querying, we define a multi-dimensional query algebra, which integrates the main multi-dimensional operators such as rotations, drill down, roll up… These operators support the constraint-based multi-dimensional modelling. Finally, we present two implementations of this algebra. First, OLAP-SQL is a textual language integrating multi-dimensional concepts (fact, dimension, hierarchy), but it is based on classical SQL syntax. This language is dedicated tospecialists such as multi-dimensional database administrators. Second, a graphical query language is presented. This language consists in a graphical representation of multi-dimensional databases, and users specify directly their queries over this graph. This approach is dedicated to non-computer scientist users.

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