We consider the problem of OS resource management for real-time and multimedia systems where multiple activities with different timing constraints must be scheduled concurrently. Time on a particular resource is shared among its users and must be globally managed in real-time and mul-timedia systems. A resource kernel is meant for use in such systems and is… (More)
In this paper, we propose a scheme of rate control for continuous UDP ow with moderate fairness. First, per-packet Relative One-way Trip Time (ROTT) of a UDP stream at a receiver on the Internet is investigated extensively, and it is found that spikes with successive plots, which we call spike-trains, often appear on a time-ROTT graph. Also,… (More)
Traditional real-time systems have largely avoided the use of disks due to their relative slow speeds and their un-predictability. However, many real-time applications including multimedia systems and real-time database applications benefit significantly from the use of disks to store and access real-time data. In this paper, we investigate the problem of… (More)
The world today is characterised by the proliferation of information sources available through media such as the WWW, databases, semi-structured files (e.g. XML documents), etc. Nevertheless, this information is usually scattered, heterogeneous and weakly structured, so it is difficult to process it automatically. DENODO Corporation has developed a mediator… (More)
We discuss how methods from social network analysis could be combined with methodologies from database mediator technology and information fusion in order to give police and other civil security decision-makers the ability to achieve predictive situation awareness. Techniques based on these ideas have been demonstrated in the EU PASR project HiTS/ISAC.
Mediator systems aim to provide an unified global data schema over distributed heterogeneous structured and semi-structured data sources. These systems must deal with limitations on the query capabilities of the sources. This paper introduces a new framework for representing source query capability along with the algorithms needed to compute the query… (More)