To realise a semantic Web of Things, the challenge of achieving efficient Resource Description Format (RDF) storage and SPARQL query performance on Internet of Things (IoT) devices with limited resources has to be addressed. State-of-the-art SPARQL-to-SQL engines have been shown to outperform RDF stores on some benchmarks. In this paper, we describe an optimisation to the SPARQL-to-SQL approach...

Linked data on the Web can be accessed by SPARQL queries. Previously executed queries to SPARQL endpoints are valuable information sources about the underlying data structure and schema of data sources. These queries reveal how resources are related to each other and they reflect the user interests on the data. Therefore, methods for query logs analysis provides a basis for extracting relevant ...

This paper discusses the design and implementation of a tool for SPARQL to SQL conversion. The converter receives a SPARQL query which is then parsed and analyzed. All three current approaches to storing RDF data in RDMS (triple store, property tables, and vertical partitioning) are supported in this paper. Depending on the tool's configuration one of these methods is chosen and a proper SQL qu...

Updates in RDF stores have recently been standardised in the SPARQL 1.1 Update specification. However, computing answers entailed by ontologies in triple stores is usually treated orthogonal to updates. Even the W3C’s recent SPARQL 1.1 Update language and SPARQL 1.1 Entailment Regimes specifications explicitly exclude a standard behaviour how SPARQL endpoints should treat entailment regimes oth...

The volume and diversity of data that is queriable via SPARQL and its increasing integration motivate the desire to query SPARQL information sources via the specification of preferred query outcomes. Such preference-based queries support the ordering of query outcomes with respect to a user’s measure of the quality of the response. In this position paper we argue for the incorporation of prefer...

SparqlFilterFlow provides a visual interface for the composition of SPARQL queries, in particular SELECT and ASK queries. It is based on the intuitive and empirically well-founded filter/flow model that has been extended to address the unique specifics of SPARQL and RDF. In contrast to related work, no structured text input is required but the queries can be created entirely with graphical elem...

Semantic Web technologies are being widely applied in life sciences. Major bioinformatics data centers started to provide heterogeneous biomedical datasets in RDF and expose them at SPARQL endpoints. SPARQL query is used to search those endpoints and the results are obtained as a SPARQL Query Results XML Format or a SPARQL Query Results JSON Format, both are essentially tabular structured data....

هدف: پیشرفت جوامع بالاخص کشورهای درحال توسعه تا حد زیادی در گرو گسترش نهادهای دانشگاهی است. هم‌چنین یکی از مهم‌ترین ویژگی‌های آموزشی، درهم‌تنیدگی ساختارهای آموزش و اشتغال واقع هر آموزشی باید بازدهی یا توجیه اقتصادی داشته باشد که عالی‌ترین نوع آن ایجاد متناسب با فراگیر بر این اساس پژوهش حاضر به بررسی وضعیت راهیابی دانشجویان فارغ‌التحصیلان کارشناسی ارشد دکتری رشته تکنولوژی بازار کار عوامل مؤثر نظ...

With the widespread adoption of Linked Data, the efficient processing of SPARQL queries gains importance. A crucial category of queries that is prone to optimization is “top-k” queries, i.e. queries returning the top k results ordered by a specified ranking function. Top-k queries can be expressed in SPARQL by appending to a SELECT query the ORDER BY and LIMIT clauses, which impose a sorting or...