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...

The International Collaborative Project on Micronucleus Frequency in Human Populations (HUMN) was organized to collect data on micronucleus (MN) frequencies in different human populations and different cell types. The test procedures considered by this project are assays using human lymphocytes (cytokinesis-block method), exfoliated epithelial cells, and other cell types. Data (including descri...

This document summarizes the proposals before the SQL3 committees to allow the addition of tables with valid-time and transaction-time support into SQL/Temporal, and explains how to use these facilities to migrate smoothly from a conventional relational system to one encompassing temporal support. Initially, important requirements to a temporal system that may facilitate such a transition are m...

Support for temporal data continues to be a requirement posed by many applications. We show that a complex object data model is an appmpriate means for handling temporal data. Firstly, we describe the main features of tempoml databases in terms of time sequences. valid time. etc. We then explain the mapping of time sequences onto recursively structured complex objects. Operations on temporal da...

There are numerous applications where we have to deal with temporal uncertainty associated with events. The Temporal Probabilistic (TP) Logic Programs should provide support for valid-time indeterminacy of events, by proposing the concept of an indeterminate instant, that is, an interval of time-points (event’s time-window) with an associated, lower and upper, probability distribution. In parti...