Quality and Utility - On the Use of Time-Value Functions to Integrate Quality and Timeliness Flexible Aspects in a Dynamic Real-Time Scheduling Environment

Scheduling methodologies for real-time applications have been of keen interest to diverse research communities for several decades. Depending on the application area, algorithms have been developed that are tailored to specific requirements with respect to both the individual components of which an application is made up and the computational platform on which it is to be executed. Many real-time scheduling algorithms base their decisions solely or partly on timing constraints expressed by deadlines which must be met even under worst-case conditions. The increasing complexity of computing hardware means that worst-case execution time analysis becomes increasingly pessimistic. Scheduling hard real-time computations according to their worst-case execution times (which is common practice) will thus result, on average, in an increasing amount of spare capacity. The main goal of flexible real-time scheduling is to exploit this otherwise wasted capacity. Flexible scheduling schemes have been proposed to increase the ability of a real-time system to adapt to changing requirements and nondeterminism in the application behaviour. These models can be categorised as those whose source of flexibility is the quality of computations and those which are flexible regarding their timing constraints. This work describes a novel model which allows to specify both flexible timing constraints and quality profiles for an application. Furthermore, it demonstrates the applicability of this specification method to real-world examples and suggests a set of feasible scheduling algorithms for the proposed problem class.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Passau

Year

2005

Author dc:creator

• Schwarzfischer, Thomas

Contributors dc:contributor

• Grass, Werner

• soft real-time
• dynamic scheduling
• time-value functions
• local search
• meta scheduling

Statement dc:rights

• Standardbedingung laut Einverständniserklärung

Repository record source_url

https://opus4.kobv.de/opus4-uni-passau/frontdoor/index/index/docId/50

OAI identifier oai:identifier

oai:kobv.de-opus4-uni-passau:50