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In this paper, we extend the classic model of timed automata with a notion of real time tasks. The main idea is to associate each discrete transition in a timed automaton with a task (an executable program). Intuitively, a discrete transition in an extended timed automaton denotes an event releasing a task and the guard on the transition specifies all the(More)
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(More)
Delay variations (jitter) in computations and communications cause degradation of performance in e.g. control applications. There are many sources of jitter, including variations in execution time and bus contention. This paper presents methods to reduce the variation of frame (message) transmission time caused by the bit-stuffing mechanism in the(More)
The use of state-of-the-art real-time techniques in industry remains infrequent. The reason for this, we believe, is threefold: (1) the lack of commercially available tools, (2) the lack of methodologies based on real-time theory throughout the complete development process, and (3) the lack of competence in real-time theory among industrial practitioners.(More)
A common computational model in distributed embedded systems is that the nodes exchange signals via a network. Most often a signal represents the state of some physical device and has a signal size ranging from a single bit up to a few bytes. Furthermore, each signal typically has a deadline requirement. The communication networks used are often based on a(More)
This paper presents a novel approach for calculating a probabilistic worst-case response-time for messages in the Controller Area Network (CAN). CAN uses a bit-stuffing mechanism to exclude forbidden bit-patterns within a message frame. The added bits eliminate the forbidden patterns but cause an increase in frame length. How much the length is increased(More)
In this paper we present a concurrency control algorithm that allows coexistence 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(More)
Industrial systems are examples of complex and often long-lived systems in which software is playing an increasingly important role. Their architectures play a crucial role in maintaining the properties of such systems during their entire life cycle. In this paper, we present the results of a case study based on a series of interviews and a workshop with(More)
A modeling process is presented for extracting timing-accurate simulation models from complex embedded real-time systems. The process is supported by two complementary methods for tool-supported model extraction, Model Synthesis and Hybrid Model Extraction. The generated models enable impact analysis for complex real-time systems with respect to dynamic(More)