Page History: CISTER Distinguished Seminar Series

November 3, 2009 - Integrating Real-World Services in Modern Enterprises ¶

Stamatis Karnouskos, SAP Research, Germany

Talk abstract:
Modern enterprises operate on a global scale and depend on complex business processes. Business continuity needs to be guaranteed, and therefore efficient information acquisition, evaluation and interaction with the real world is of key importance. The infrastructure envisioned is a heterogeneous one, where millions devices are interconnected, ready to receive instructions and create event notifications, and where the most advanced ones depict self-behavior (e.g. self-management, self-healing, self-optimization etc) and collaborate. This can lead to a paradigm change as business logic can now be intelligently distributed to several layers such as the network or even the device layer creating new opportunities but also challenges that need to be assessed. Future Enterprise Services will be in position to better integrate state and events of the physical world in a timely manner, and hence to lead to more diverse, highly dynamic and efficient business applications.

Speaker Bio.:
Stamatis Karnouskos is with SAP Research (www.sap.com) where he investigates the added value of integrating networked embedded devices in enterprise systems.

October 28, 2009 - A Timeband Framework for Modelling Real-Time Systems¶

Alan Burns, University of York, UK

Talk abstract:
Complex real-time systems, must integrate physical processes with digital control, human operation and organizational structures. New scientific foundations are required for specifying, designing and implementing these systems. One key challenge is to cope with the wide range of time scales and dynamics inherent in such systems. To exploit the unique properties of time, with the aim of producing more dependable computer-based systems it is desirable to explicitly identify distinct time bands in which the system is situated. Such a framework enables the temporal properties and associated dynamic behaviour of existing systems to be described and the requirements for new or modified systems to be specified. A system model based on a finite set of distinct time bands is motivated and described in this talk.

Speaker Bio.:
Professor Alan Burns is a member of the Department of Computer Science, University of York, U.K. His research interests cover a number of aspects of real-time systems including the assessment of languages for use in the real-time domain, distributed operating systems, the formal specification of scheduling algorithms and implementation strategies, and the design of dependable user interfaces to real-time applications. Professor Burns has authored/co-authored 450 papers/reports and 15 books. Many of these are in the real-time area. His teaching activities include courses in Operating Systems and Real-time Systems. He is a member of ARTIST - the EU Centre of Excellence in Real-Time and Embedded Systems. He is editor of a recent review of real-time programming languages. In 2009 Professor Burns was elected a Fellow of the Royal Academy of Engineering.

Speaker's Homepage: http://www-users.cs.york.ac.uk/~burns/

June 5, 2009 - A Dynamic Scheduling Approach to Designing Flexible Safety-Critical Systems¶

Luís Almeida, FEUP, Portugal

Talk abstract:
The design of safety-critical systems has typically adopted static techniques to simplify error detection and fault tolerance. However, economic pressure to reduce costs is exposing the limitations of those techniques in terms of efficiency in the use of system resources. In some industrial domains, such as the automotive, this pressure is too high, and other approaches to safety must be found, e.g., capable of providing some kind of fault tolerance but with graceful degradation to lower costs, or also capable of adapting to instantaneous requirements to better use the computational/communication resources.

This paper analyses the development of systems that exhibit such level of flexibility, allowing the system configuration to evolve within a well-defined space. Two options are possible, one starting from the typical static approach but introducing choice points that are evaluated only at runtime, and another one starting from an open systems approach but delimiting the space of possible adaptations. The paper follows the latter and presents a specific contribution, namely, the concept of local utilization bound, which supports a fast and efficient schedulability analysis for on-line resource management that assures continued safe operation. Such local bound is derived off-line for the specific set of possible configurations, and can be significantly higher than any generic non-necessary utilization bound such as the well known Liu and Layland's bound for Rate-Monotonic scheduling.

Paper: A Dynamic Scheduling Approach to Designing Flexible Safety-Critical Systems (pdf)
Talk slides: NA

July 13, 2010 - Message Scheduling in TT Protocols¶

Zdenek Hanzalek, Czech Technical University in Prague, Czech Republic

Talk abstract:
This talk presents the algorithms that allow creating of a static schedule for Profinet IO IRT (an industrial Ethernet protocol standardized in IEC61158), IEEE 802.15.4/ZigBee (beacon enabled cluster-tree Wireless Sensor Network) and preliminary results for FlexRay. Furthermore, the problem is extended by useful temporal constraints (i.e. release dates, deadlines and end-to-end deadlines of the messages) providing a greater flexibility with respect to the individual messages. Due to this flexibility, it is possible to place the selected messages in various parts of the communication cycle (in order to increase the computational time available for the main-controller application, or to retransmit the message without hold-up in the router, or to add new messages into original schedule). The solution is based on a formulation of the scheduling problem in terms of the Resource Constrained Project Scheduling with Temporal Constraints. Experiments (computations, simulations and the ones with real HW) show that these algorithms are applicable to industrial-size problems.

Speaker's Homepage: http://dce.felk.cvut.cz/hanzalek/