| 1. |
- Behnam, Moris, et al.
(författare)
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A Hierarchical Approach for Reconfigurable and Adaptive Embedded Systems
- 2008
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Ingår i: APRES'08 Adaptive and Reconfigurable Embedded Systems. ; , s. 51-54
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Konferensbidrag (refereegranskat)abstract
- Adaptive and reconfigurable embedded systems have been gaining an increasing interest in the past year from both academics and industry. This paper presents our work on hierarchical scheduling frameworks (HSF) intended as a backbone architecture facilitating the implementation of operating system support for adaptability and reconfigurability.
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| 2. |
- Behnam, Moris
(författare)
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Hierarchical Real Time Scheduling and Synchronization
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Hierarchical Scheduling Framework (HSF) has been introduced to enable compositional schedulability analysis and execution of embedded software systems with real-time constraints. In this thesis, we consider a system consisting of a number of semi-independent components called subsystems, and these subsystems are allowed to share logical resources. The HSF provides CPU-time to the subsystems and it guarantees that the individual subsystems respect their allocated CPU budgets. However, if subsystems are allowed to share logical resources, extra complexity with respect to analysis and run-time mechanisms is introduced. In this thesis we address three issues related to hierarchical scheduling of semi-independent subsystems. In the first part, we investigate the feasibility of implementing the hierarchical scheduling framework in a commercial operating system, and we present the detailed figures of various key properties with respect to the overhead of the implementation. In the second part, we studied the problem of supporting shared resources in a hierarchical scheduling framework and we propose two different solutions to support resource sharing. The first proposed solution is called SIRAP, a synchronization protocol for resource sharing in hierarchically scheduled open real-time systems, and the second solution is an enhanced overrun mechanism. In the third part, we present a resource efficient approach to minimize system load (i.e., the collective CPU requirements to guarantee the schedulability of hierarchically scheduled subsystems). Our work is motivated from a tradeoff between reducing resource locking times and reducing system load. We formulate an optimization problem that determines the resource locking times of each individual subsystem with the goal of minimizing the system load subject to system schedulability. We present linear complexity algorithms to find an optimal solution to the problem, and we prove their correctness
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| 3. |
- Behnam, Moris, et al.
(författare)
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Scheduling of Semi-Independent Real-Time Components: Overrun Methods and Resource Holding Times
- 2008
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Ingår i: Proceedings of the 13th IEEE International Conference on Emerging echnologies and Factory Automation (ETFA’08). - 9781424415052 ; , s. 575-582
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Konferensbidrag (refereegranskat)abstract
- The Hierarchical Scheduling Framework (HSF) has been introduced as a design-time framework enabling compositional schedulability analysis of embedded software systems with real-time properties. In this paper a system consists of a number of semi-independent components called subsystems. Subsystems are developed independently and later integrated to form a system. To support this design process, our proposed methods allow nonintrusive configuration and tuning of subsystem timing behaviour via subsystem interfaces for selecting scheduling parameters. This paper considers two methods to handle overruns due to resource sharing between subsystems in the HSF. We present the scheduling algorithms for overruns and their associated schedulability analysis, together with analysis that shows under what circumstances one or the other overrun method is preferred. Furthermore, we show how to calculate resource-holding times within our framework.
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| 4. |
- Behnam, Moris, et al.
(författare)
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Synchronization protocols for hierarchical real-time scheduling frameworks
- 2008
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Ingår i: Proceedings of the 1st Workshop on Compositional Theory and Technology for Real-Time Embedded Systems (CRTS'08) in conjunction with the 29th IEEE International Real-Time Systems Symposium (RTSS'08), Barcelona, Spain.
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Konferensbidrag (refereegranskat)
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| 5. |
- Behnam, Moris, et al.
(författare)
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Towards Hierarchical Scheduling in VxWorks
- 2008
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Ingår i: OSPERT 2008, Proceedings of the Fourth International Workshop on Operating Systems Platforms for Embedded Real-Time Applications. ; , s. 63-72
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Konferensbidrag (refereegranskat)abstract
- Over the years, we have worked on hierarchical schedulingframeworks from a theoretical point of view. In thispaper we present our initial results of the implementationof our hierarchical scheduling framework in a commercialoperating system VxWorks. The purpose of the implementationis twofold: (1) we would like to demonstrate feasibilityof its implementation in a commercial operating system,without having to modify the kernel source code, and (2) wewould like to present detailed figures of various key propertieswith respect to the overhead of the implementation.During the implementation of the hierarchical scheduler,we have also developed a number of simple task schedulers.We present details of the implementation of Rate-Monotonic(RM) and Earliest Deadline First (EDF) schedulers. Finally,we present the design of our hierarchical schedulingframework, and we discuss our current status in the project.
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| 6. |
- Benzi, Francesco, et al.
(författare)
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Towards the Powerline Alternative in Automotive Applications
- 2008
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Ingår i: Proceedings of the Work-In-Progress (WIP) session of the 7th IEEE International Workshop on Factory Communication Systems (WFCS'08), Dresden, Germany. - 9781424423491 ; , s. 259-262
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Konferensbidrag (refereegranskat)abstract
- The Power Line technology has received an increasing attention in the last decades due to its inherent benefits, mainly related to the reduction of cabling and associated costs. Power Line Communication (PLC) was first employed in power utilities and since the 80s in home automation, too. However, its use in the automotive field received relatively little attention. This paper revisits the related work in using PLC technology for communication within the automotive domain and outlines its possible benefits. Then, it focuses on the issues that need to be addressed when introducing the PLC in the automotive domain. The final goal of this work is to carry out a practical assessment of the PLC technology in the referred domain that may open the way for future use in industrial scale.
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| 7. |
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| 8. |
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| 9. |
- Marau, Ricardo, et al.
(författare)
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Server-based real-time communications of Switched Ethernet
- 2008
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Ingår i: Proceedings of the 1st Workshop on Compositional Theory and Technology for Real-Time Embedded Systems (CRTS'08) in conjunction with the 29th IEEE International Real-Time Systems Symposium (RTSS'08), Barcelona, Spain.
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Konferensbidrag (refereegranskat)
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| 10. |
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