| 1. |
- Behnam, Moris, 1973-, et al.
(författare)
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Schedulability analysis of synchronization protocols based on overrun without payback for hierarchical scheduling frameworks revisited
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, we show that both global as well as local schedulability analysis of synchronization protocols based on the stack resource protocol (SRP) and overrun without payback for hierarchical scheduling frameworks based on fixed-priority pre-emptive scheduling (FPPS) are pessimistic.We present improved global and local schedulability analysis,illustrate the improvements by means of examples, and show that the improved global analysis is both uniform and sustainable.We evaluate the improved global and local schedulabilityanalysis based on an extensive simulation study and comparethe results with the existing analysis.
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| 2. |
- Bohlin, Markus, et al.
(författare)
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Safe Shared Stack Bounds in Systems with Offsets and Precedences
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The paper presents two novel methods to bound the stack memory used in preemptive, shared stack, real-time systems. The first method is based on branch-and-bound search for possible preemption patterns, and the second one approximates the first in polynomial time. The work extends previous methods by considering a more general taskmodel, in which all tasks can share the same stack. In addition, the new methods account for precedence and offset relations. Thus, the methods give tight bounds for a large set of realistic systems. The methods have been implemented and a comprehensive evaluation, comparing our new methods against each other and against existing methods, is presented. The evaluation shows that our exact method can significantly reduce the amount of stack memory needed. In our simulations, a decrease in the order of 40% was typical, with a runtime in the order of seconds. Our polynomial approximation consequently yields about 20% higher bound than the exact method.
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| 3. |
- Bures, Tomas, et al.
(författare)
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Towards Component Modelling of Embedded Systems in the Vehicular Domain
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The complexity of software and electronics in vehicular systems has increased significantly over last few years - up to the point when it is difficult to manage it with existing development methods. In this paper we aim at using components for managing the complexity in vehicular systems. Compared to other approaches, the distinguishing feature of our work is using and benefiting from components throughout the whole development process (from early design to development and deployment). Based on the elaboration of the specifics of vehicular systems (resource constraints, real-time requirements, hard demands on reliability), the paper identifies concerns that need to be addressed by a component model for this domain. It also outlines basic features and characteristics of such a component model and discusses how relevant existing formalisms and component models relate to it and how they could be reused within the proposed approach.
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| 4. |
- Carlson, Jan, et al.
(författare)
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Feasibility of migrating analysis and synthesis mechanisms from ProCom to IEC 61499
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents the initial results from the Assist project at Mälardalen University, funded by the ABB Software Research Grant Program. The project aims to bridge the gap between recent academic research achievements in the area of control- and model based development of embedded systems, and concrete industrial needs and state of practice in this domain. Concretely, the focus of the project is to investigate how novel timing analysis and code synthesis techniques developed in the context of ProCom, an academic component model for embedded systems, can be extended and adapted in order to be applicable to IEC 61499.
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| 5. |
- Causevic, Aida, et al.
(författare)
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Algorithmic Computation of Strongest Postconditions of Services as Priced Timed Automata
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Service-Oriented Systems (SOS) have gained importance in different application domains thanks to their ability to enable reusable functionality provided via well-defined interfaces, and the increased opportunities to compose existing units, called services, into various configurations. Developing applications in such a setup, by reusing existing services, brings some concerns regarding the assurance of the expected Quality-of-Service (QoS), and correctness of the employed services. In this paper, we provide a formal mechanism of computing service guarantees, automatically. We assume service models annotated with pre- and postconditions, their semantics given as Priced Timed Automata (PTA), and the forward analysis method for checking the service correctness w.r.t. given requirements. Under these assumptions, we show how to compute the strongest postcondition of the corresponding automata algorithmically, with respect to the specified precondition. The approach is illustrated on a small example of a service modeled as Priced Timed Automaton (PTAn).
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| 6. |
- Enoiu, Eduard Paul, et al.
(författare)
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Towards the Analysis and Verification of EAST-ADL Models using UPPAAL PORT
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A system’s architecture influence on the functions and other properties of embedded systems makes its high level analysis and verification very desirable. EAST-ADL is an architecture description language dedicated to automotive embedded system design with focus on structural and functional modeling. The behavioral description is not integrated within the execution semantics, which makes it harder to transform, analyze, and verify EAST-ADL models. Model-based techniques help address this issue by enabling automated transformation between different design models, and providing means for simulation and verification. We present a verification tool, called ViTAL, which provides the possibility to express the functional EAST-ADL behavior as timed automata models, which have precise semantics and can be formally verified. The ViTAL tool enables the transformation of EAST-ADL functional models to the UPPAAL PORT tool for model checking. This method improves the verification of functional and timing requirements in EAST-ADL, and makes it possible to identify dependencies and potential conflicts between different vehicle functions before the actual AUTOSAR implementation.
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| 7. |
- Feljan, Juraj, et al.
(författare)
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Classification and survey of component models
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- As component-based software engineering is growing and its usage expanding, more and more component models are developed. In this report we present a survey of software component models in which models are described and classified respecting the classification framework for component models proposed by CrnkoviA‡ et. al. [1]. This framework specifies several groups of important principles and characteristics of component models: lifecycle, constructs, specification and management of extra-functional properties, and application domain. This report analyzes a considerable amount of component models, including widely used industrial models, as well as research models.
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| 8. |
- Flemström, Daniel
(författare)
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Tech. Report: Similarity Function Evaluation
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents details on and an in-depth evaluation of a similarity function used for detecting similar test steps in manual test cases, written in natural language. Using an industrial data set of 65 000 test steps, we show that even though the similarity function builds on standard functions from the open source data base Postgres, it is capable of finding similarities in parity of what the state of the art suggests. Rather few miss classifications were found. We also show that by fine tuning the function, the number of clusters of similar can be reduced by 13%. Manual inspection further shows that there is potential to reduce the set of clusters even more.
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| 9. |
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| 10. |
- Inam, Rafia, 1974-, et al.
(författare)
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Run-Time Component Integration and Reuse in Cyber-Physical Systems
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We present the concept of runnable virtual nodes as a means to achieve predictable integration and reuse of software components in cyber-physical systems. A runnable virtual nodeis a coarse-grained real-time component that provides functional and temporal isolation with respect to its environment.Its interaction with the environment is bounded both by a functional and a temporal interface, and the validity of itsinternal temporal behavior is preserved when integrated with other components or when reused in a new environment.Our realization of runnable virtual nodes exploits the latest techniques for hierarchical scheduling to achieve temporalisolation, and the principles from component-based software-engineering to achieve functional isolation. In the paperwe present a proof-of-concept case study, implemented in the ProCom component-technology executing on top of FreeRTOSbased hierarchical scheduling framework.
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