Real time systems are systems in which there is a commitment for timely response by the computer to external stimuli. Real time applications have to function correctly even in presence of faults. Fault tolerance can be achieved by either hardware or software or time redundancy. Safety-critical applications have strict time and cost constraints, which means that not only faults have to be tolera...

Inhaltsverzeichnis Abbildungsverzeichnis v Tabellenverzeichnis ix Verzeichnis der verwendeten Symbole xi 1 Einleitung 1 1.

We present a scheduling architecture that enables the implementation of deadline-based scheduling policies. The architecture is used to give real-time capabilities to a custom Java virtual machine. This framework retains a clear separation between generic kernel mechanisms and upper level scheduling classes. A pure earliest deadline first algorithm can be implemented, but enhanced policies such...

We propose in this paper, a method to automatically map runnables (blocks of code with dedicated functionality) with real-time constraints to tasks (or threads). We aim at reducing the number of tasks runnables are mapped to, while preserving the schedulability of the initial system. We consider independent tasks running on a single processor. Our approach has been applied with fixed-task or fi...

A large fraction of the total electric load is comprised of end-use devices whose energy demand is inherently deferrable in time. Of interest is the potential to leverage on such latent flexibility in demand to absorb variability in power supplied from intermittent renewable generation. The challenge, however, lies in designing incentives to reliably induce the desired response in demand. To th...

The Controller Area Network has a maximum transmission rate of 1 Mbitk and its fixed priorities-based medium access control limits the maximum bus utilisation when timeliness guarantees are required. An implementation of earliest deadline first (EDF) message scheduling on CAN, based on the F’IT CAN protocol, is presented, which allows higher utilisation factors with timeliness guarantees. The a...

Packet networks are currently enabling the integration of traffic with a wide range of characteristics that extend from video traffic with stringent QoS requirements to the best-effort traffic requiring no guarantees. QoS guarantees can be provided in conventional packet networks by the use of proper packet scheduling algorithms. As a computer revolution, many scheduling algorithms have been pr...

Real-time disk I/O scheduling is extremely important to the performance improvement of the whole real-time system since the disk devices are the system’s bottleneck. To meet time constraints, some conventional algorithm, such as EDF, Least Slack Time First, Rate Monotonic, can be used to schedule disk I/O. However, these algorithms ignore the relative position of requested data on the disks, he...

The multiprocessor partitioned scheduling of sporadic task systems is considered. The problem of obtaining feasible partitionings under both Earliest Deadline First (EDF) and Fixed Priority (FP) scheduling is represented as integer linear programs comprised of binary (zero / one) integer variables only.

In this paper, we validate the performance of Moody’s KMV EDF credit measures in its timeliness of default prediction, ability to discriminate good firms from bad firms, and accuracy of levels in three regions: North America, Europe, and Asia. We focus on the period 1996–2006 for most of our tests. Wherever possible, we compare the performance to that of other popular alternatives, such as agen...