Ramon R. H. Schiffelers

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The verification formalism / modeling and simulation language hybrid Chi is defined. The semantics of hybrid Chi is formally specified using Structured Operational Semantics (SOS) and a number of associated functions. The χ syntax and semantics can also deal with local scoping of variables and/or channels, implicit differential algebraic equations, such as(More)
The hybrid χ (Chi) formalism integrates concepts from dynamics and control theory with concepts from computer science, in particular from process algebra and hybrid automata. It integrates ease of modeling with a straightforward, structured operational semantics. Its 'consistent equation semantics' enforces state changes to be consistent with invariants as(More)
A compositional interchange format for hybrid systems is defined in terms of an interchange automaton , allowing arbitrary differential algebraic equations, including fully implicit or switched DAEs, discrete, continuous and algebraic variables, that can be internal or external, urgency conditions , and operators for parallel composition, action hiding,(More)
Hybrid Chi is a process algebra for the modeling and analysis of hybrid systems. It enables modular specification of hybrid systems by means of a large set of atomic statements and operators for combining these. For the efficient implementation of simulators and the verification of properties of hybrid systems it is convenient to have a model that uses a(More)
In the Model-Based Engineering (MBE) paradigm, models are the core elements in the design process of a system from its requirements to the actual implementation of the system. By means of Supervisory Control Theory (SCT), supervisory controllers (supervisors) can be synthesized instead of designing them manually. In this paper, a framework based on the(More)
ASML is the world's leading provider of complex lithography systems for the semiconductor industry. Such systems consist of numerous servo control systems. To design such control systems, a multi-disciplinary model-based development environment has been developed. It is based on a set of domain specific languages (DSLs) describing A) the transducers and(More)
—We investigate the notion of quality in QVT Operational Mappings (QVTo), one of the languages defined in the OMG standard on model-to-model transformations. We utilize a bottom-up approach, starting with a broad exploratory study including QVTo expert interviews, a review of existing material, and introspection. We then formalize QVTo transformation(More)
—Tasks executing on general purpose multiprocessor platforms exhibit variations in their execution times. As such, there is a need to explicitly consider robustness, i.e., tolerance to these fluctuations. This work aims to quantify the robustness of schedules of directed acyclic graphs (DAGs) on multiprocessors by defining probabilistic robustness metrics(More)
—Latest trends in embedded platform architectures show a steady shift from high frequency single core platforms to lower-frequency but highly-parallel execution platforms. Scheduling applications with stringent latency requirements on such multiprocessor platforms is challenging. Our work is motivated by the scheduling challenges faced by ASML, the world's(More)