In this paper, we present a spatiotemporal information integrated RDF data management system, called g-Store. In g-Store, some entities have spatiotemporal features, and some statements have valid time intervals and occurring locations. We introduce some spatiotemporal assertions into the SPARQL query language to answer the spatiotemporal range queries and join queries. Some examples are listed...

The databases of a wide range of applications, e.g., in data warehousing, store multiple states of time-evolving data. These databases contain a substantial part of now-relative data: data that became valid at some past time and remains valid until the current time. More specifically, two temporal aspects of data are frequently of interest, namely valid time, when data is true, and transaction ...

Although temporal databases have received considerable at tent ion as a topic for research, little work in the area has paid at tent ion t o the concurrency control mechanisms that might be employed in temporal databases. This paper describes how the not ion of the current time also called ‘now’ i n valid-time databases can cause standard serialisation theory t o give what are a t least unintui...

In bitemporal databases, current facts and transaction states are modelled using a special value to represent the current time (such as a minimum or maximum timestamp or NULL). Previous studies indicate that the choice of value for now (i.e. the current time) significantly influences the efficiency of accessing bitemporal data. This paper introduces a new approach to represent now, in which cur...

Disinfection by-products (DBPs) in drinking water represent a public health issue and a challenge for epidemiology to provide evidence towards the causation of various hypothesized health effects. Validation of a biomarker of exposure to DBPs is a strategy to achieve progress which has been advocated. The objective of this study was to validate urinary trichloroacetic acid (TCAA) excretion as a...

This paper provides a systematic and comprehensive study of the underlying semantics of temporal databases, summarizing selected results of an intensive collaboration between the two authors over the five-years period from 1991 to 1995. We first examine how facts may be associated with time, most prominently with one or more dimensions of valid time and transaction time. One common case is that...

As a stressful and sensitive task, driving can be disturbed by various factors from the health condition of the driver to the environmental variables of the vehicle. Continuous monitoring of driving hazards and providing the most appropriate business services to meet actual needs can guarantee safe driving and make great use of the existing information resources and business services. However, ...

By contrast, the flat relational tables of traditional DBMSs are not well-suited for temporally grouped representations [8]; moreover, significant extensions are required to support temporal information in SQL and, in the past, they were poorly received by SQL standard committees. We will show that (i) XML hierarchical structure can naturally represent the history of databases and XML documents...

Enhancing continuous queries over data streams with temporal functions and predicates enriches the expressive power of those queries. While traditional continuous queries retrieve only the values of attributes, temporal continuous queries retrieve the valid time intervals of those values as well. Correctly evaluating such queries requires the coalescing of adjacent timestamps for value-equivale...

Multi-temporal XML databases supporting schema versioning contain XML elements of different temporal formats (snapshot, transaction-time, valid-time, and bitemporal), defined under several XML schema versions. These databases support three types of data updates concerned with the time when updates are made: retroactive, proactive, or on-time, dealing with past, future, or current data respectiv...