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...

Real-world objects are inherently spatially and temporally referenced, and many database applications rely on databases that record the past, present, and anticipated future locations of, e.g., people or land parcels. As a result, indices that efficiently support queries on the spatio-temporal extents of objects are needed. In contrast, past indexing research has progressed in largely separate ...

In applications like nancial trading, scheduling, manufacturing and process control, time based predicates in queries and rules are very important. There is also a need to de ne sets of time points or intervals. We refer to these sets as calendars. This paper presents a system of calendars that allows speci cation of natural-language time-based expressions, maintenance of valid time in database...

The bitemporal conceptual data model proposed for handling time within the framework of relational data model can be eflcctiuely represented using valid-time and transaction-time intervals as time-stamps on tuples. We observe that in many real-world applications, valid-time interval for a fact is not known completely while entering the fact in a temporal database. The model provides ‘open’ inte...

A standard relation has two dimensions: attributes and tuples. A temporal relation contains two additional orthogonal time dimensions, namely, valid time and transaction time. Valid time records when facts are true in the modeled reality, and transaction time records when facts are stored in the temporal relation. Although, in general, there are no restrictions between the valid time and transa...

Application development on top of database systems is heavily based on the existence of embedded and 4GL languages. However, the issue of designing and implementing embedded or 4GL temporal languages has not been addressed insofar. In this paper, we present a design approach for implementing an embedded temporal language that supports valid time. Furthermore, we introduce implementation techniq...

Most data managed by existing, real-world database applications is time referenced. Data warehouses are good examples. Often, two temporal aspects of data are of interest, namely valid time, when data is true in the mini-world, and transaction time, when data is current in the database, resulting in so-called bitemporal data. Like spatial data, bitemporal data thus has associated two-dimensiona...