| 1. |
- Amirijoo, Mehdi, 1978-, et al.
(author)
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Finite Horizon QoS Prediction of Reconfigurable Firm Real-Time Systems
- 2006
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In: IEEE International Conference on Embedded and Real-Time Computing Systems and Applications,2006. - Los Alamitos, California, USA : IEEE Computer Society. ; , s. 233-
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Conference paper (peer-reviewed)abstract
- Updating real-time system software is often needed in response to errors and added requirements to the software. Stopping a running application, updating the software, and then restarting the application is not suitable for systems with high availability requirements. On the other hand, dynamically updating a system may increase the execution time of the tasks, thus, degrading the performance of the system. Degradation is not acceptable for performance-critical real-time systems as there are strict requirements on the performance. In this paper we present an approach that enables dynamic reconfiguration of a real-time system, where the performance of the system during a reconfiguration satisfies a given worst-case performance specification. Evaluation shows that the presented method is efficient in guaranteeing the worst-case performance of dynamically reconfigurable firm real-time systems.
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| 2. |
- Amirijoo, Mehdi, 1978-, et al.
(author)
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Raising Motivation in Real-time Laboratories : The Soccer Scenario
- 2004
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In: Technical Symposium on Computer Science Education, SIGCSE,2004. - USA : Association for Computing Machinery (ACM). ; , s. 265-
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Conference paper (peer-reviewed)abstract
- Real-time systems is a topic that one cannot overlook in an engineer's education. However, teaching real-time systems in an undergraduate syllabus is a challenging experience due to conflicting constraints placed on such a course. In this paper we present a new setup for laboratories in the real-time systems course that successfully meets the constraints of mass education, stable environment management, short time span for the labs, and still enables deep involvement of students in the central topic of resource allocation with high motivation.
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| 3. |
- Gustafsson, Thomas, 1975-, et al.
(author)
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Engineering Active Behavior of Embedded Software to Improve Evolution and Performance : an Aspect-Oriented Approach
- 2007
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In: The 22nd Annual ACM Symposium on Applied Computing,2007. - New York : ACM. - 1595934804
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Conference paper (peer-reviewed)abstract
- In this paper we propose a novel aspect-oriented scheme for implementing active behavior in embedded software with requirements on data freshness. The scheme improves system performance by combining active behavior in terms of event-condition-action (ECA) rules and on-demand updating. We design and implement the scheme in terms of aspects, thereby exploiting aspect-oriented programming technology to efficiently handle crosscutting nature of active behavior. The benefits of our approach are demonstrated using a case study of an embedded database system called COMET. Namely, simulations on the COMET database indicate that its performance increases by incorporating our scheme. Furthermore, using the COMET example we show that aspect-oriented implementation of active behavior has benefits when it comes to easier evolution of the system.
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| 4. |
- Nyström, Dag, et al.
(author)
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COMET : A Component-Based Real-Time Database for Automotive Systems
- 2004
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In: Workshop on Software Engineering for Automotive Systems at 26th International Conference on Software engineering ICSE04,2004.
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Conference paper (peer-reviewed)abstract
- With the increase of complexity in automotive control systems, the amount of data that needs to be managed is also increasing. Using a real-time database management system (RTDBMS) as a tightly integrated part of the software development process can give significant benefits with respect to data management. However, the variability of data management requirements in different systems, and the heterogeneousness of the nodes within a system may require a distinct database configuration for each node. In this paper we introduce a software engineering approach for generating RTDBMS configurations suitable for resource-constrained automotive control systems, denoted the COMET development suit. Using software engineering tools to assist developers with design and analysis of the system under development, different database configurations can be generated from pre-fabricated components. Each generated COMET database contains only functionality required by the node it is executing on.
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| 5. |
- Nyström, Dag, et al.
(author)
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Pessimistic Concurrency-Control and Versioning to Support Database Pointers in Real-Time Databases
- 2004
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In: 16th Euromicro Conference on Real-Time Systems ECRTS04,2004. - Los Alamitos, California : IEEE Computer Society Press.
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Conference paper (peer-reviewed)abstract
- In this paper we present a concurrency control algorithm that allows co-existence of soft real-time, relational database transactions, and hard real-time database pointer transactions in real-time database management systems. The algorithm uses traditional pessimistic concurrency control i.e. locking for soft transactions and versioning for hard transactions to allow them to execute regardless of any database lock. We provide formal proof that the algorithm is deadlock free and formally verify that transactions have atomic semantics. We also present an evaluation that demonstrates significant benefits for both soft and hard transactions when our algorithm is used. The proposed algorithm is suited for resource-constrained safety critical, real-time systems that have a mix of hard real-time control applications and soft real-time management, maintenance, or user-interface applications.
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| 6. |
- Tesanovic, Aleksandra, 1976-, et al.
(author)
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Application-Tailored Database Systems : a Case of Aspects in an Embedded Database
- 2004
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In: 8th International Database Engineering and Applications Symposium IDEAS04,2004. - Los Alamitos, California : IEEE Computer Society. ; , s. 291-
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Conference paper (peer-reviewed)abstract
- Current techniques used to design and implement database systems do not provide support for efficient implementation of crosscutting concerns in the database software, e.g., failure detection, database policies such as concurrency control and scheduling, and synchronization. Aspect-oriented software development (AOSD) is a new technique that provides an efficient way of modularizing crosscutting concerns in software systems. In this paper we evaluate the effectiveness of applying AOSD to database systems thereby paving way for successful application of aspect languages to the database domain. Our focus is on embedded database systems, as a representative for a class of database systems. We show, by analyzing and re-engineering one commercial well-known embedded database system Berkeley database, that aspect-orientation has promise, especially in enabling development of tailorable, maintainable, and evolvable database systems.
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| 7. |
- Tesanovic, Aleksandra, 1976-, et al.
(author)
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Aspect-Level WCET Analyzer : a Tool for Automated WCET Analysis of a Real-Time Software Composed Using Aspects and Components
- 2003
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In: 3rd International Workshop on Worst-Case Execution Time Analysis WCET 2003,2003.
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Conference paper (peer-reviewed)abstract
- Increasing complexity in development of real-time systems requires the integration of new software engineering techniques, such as aspect-oriented and component-based software development,with real-time system development. Since software technology for building real-time systems has to support timeliness,methods and tools for analyzing temporal behavior of the softwarecomposed out of components and aspects are needed. We contribute by providing a tool that enables automated worst-case execution time analysis of different configurations of aspects and components.
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| 8. |
- Tesanovic, Aleksandra, 1976-, et al.
(author)
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Aspect-Level Worst-Case Execution Time Analysis of Real-Time Systems Compositioned Using Aspects and Components
- 2003
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In: 27th IFAC IFIP IEEE Workshop on Real-Time Programming WRTP03,2003. - Kidlington : Elsevier. ; , s. 129-
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Conference paper (peer-reviewed)abstract
- Increasing complexity in development of real-time systems accompanied by the demand for enabling their configurability requires the integration of aspect-oriented software development with real-time system development. Since software technology for building real-time systems has to support predictability in the time domain, methods and tools for analyzing temporal behavior of the aspect-oriented software are needed. Knowing worst-case execution time is of primary importance for timing analysis of real-time systems. We contribute by providing support for predictable aspect-oriented software development, by enabling symbolic worst-case execution time analysis of the aspect-oriented software systems.
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| 9. |
- Tesanovic, Aleksandra, 1976-, et al.
(author)
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Aspects and Components in Real-Time System Development : Towards Reconfigurable and Reusable Software
- 2004
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In: Journal of Embedded Computing. - 1740-4460 .- 1875-9025. ; 1:1
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Journal article (peer-reviewed)abstract
- Increasing complexity of real-time systems, and demands for enabling their configurability and reusability are strong motivations for applying new software engineering principles, such as aspect-oriented and component-based development.In this paper we introduce a novel concept of aspectual component-based real-time system development. The concept is based on a design method that assumes composition of real-time systems into components and aspects, and provides a real-time component model that supports the notion of time and temporal constraints, space and resource management constraints, and composability. Initial results show that the successful application of the proposed concept has a positive impact on real-time system development in enabling efficient configuration of real-time systems, improved reusability and flexibility of real-time software, and modularization of crosscutting concerns. We provide arguments for this by presenting an application of the proposed concept on the design and development of a configurable embedded real-time atabase, called COMET. Furthermore, using the COMET system as an example, we introduce a novel way of handling concurrency in a real-time database system, where concurrency is modeled as an aspect crosscutting the system.
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| 10. |
- Tešanović, Aleksandra, 1976-
(author)
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Developing Reusable and Reconfigurable Real-Time Software using Aspects and Components
- 2006
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Doctoral thesis (other academic/artistic)abstract
- Our main focus in this thesis is on providing guidelines, methods, and tools for design, configuration, and analysis of configurable and reusable real-time software, developed using a combination of aspect-oriented and component-based software development. Specifically, we define a reconfigurable real-time component model (RTCOM) that describes how a real-time component, supporting aspects and enforcing information hiding, could efficiently be designed and implemented. In this context, we outline design guidelines for development of real-time systems using components and aspects, thereby facilitating static configuration of the system, which is preferred for hard real-time systems. For soft real-time systems with high availability requirements we provide a method for dynamic system reconfiguration that is especially suited for resourceconstrained real-time systems and it ensures that components and aspects can be added, removed, or exchanged in a system at run-time. Satisfaction of real-time constraints is essential in the real-time domain and, for real-time systems built of aspects and components, analysis is ensured by: (i) a method for aspectlevel worst-case execution time analysis; (ii) a method for formal verification of temporal properties of reconfigurable real-time components; and (iii) a method for maintaining quality of service, i.e., the specified level of performance, during normal system operation and after dynamic reconfiguration.We have implemented a tool set with which the designer can efficiently configure a real-time system to meet functional requirements and analyze it to ensure that non-functional requirements in terms of temporal constraints and available memory are satisfied.In this thesis we present a proof-of-concept implementation of a configurable embedded real-time database, called COMET. The implementation illustrates how our methods and tools can be applied, and demonstrates that the proposed solutions have a positive impact in facilitating efficient development of families of realtime systems.
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