Concurrent Design of Embedded Control Software

Embedded software design for mechatronic systems is becoming an increasingly time-consuming and error-prone task. In order to cope with the heterogeneity and complexity, a systematic model-driven design approach is needed, where several parts of the system can be designed concurrently. There is however a trade-off between concurrency efficiency and integration efficiency. In this paper, we present a case study on the development of the embedded control software for a real-world mechatronic system in order to evaluate how we can integrate concurrent and largely independent designed embedded system software parts in an efficient way. The case study was executed using our embedded control system design methodology which employs a concurrent systematic model-based design approach that ensures a concurrent design process, while it still allows a fast integration phase by using automatic code synthesis. The result was a predictable concurrently designed embedded software realization with a short integration time

Modeling resource sharing using FSM-SADF

This paper proposes a modeling approach to capture the mapping of an application on a platform. The approach is based on Scenario-Aware Dataflow (SADF) models. In contrast to the related work, we express the complete design-space in a single formal SADF model. This allows us to have a compact and explorable state-space linked with an executable model capable of symbolically analyzing different mappings for their timing behavior. We can model different bindings for application tasks, different static-orders schedules for tasks bound in shared resources, as well as naturally capturing resource claiming/unclaiming using SADF semantics. Moreover, by using the inherent properties of dataflow graphs and the dynamic behavior of a Finite-State Machine, we can model different levels of pipelining, such as full application pipelining and interleaved pipelining of consecutive executions of the application. The size of the model is independent of the number of executions of the application. Since we are able to capture all this behavior in a single SADF model we can use available dataflow analysis, such as worst-case and best-case throughput and deadlock-freedom checking. Furthermore, since the model captures the design-space independently of the analysis technique, one can use different exploration approaches to analyze different sets of requirements

Population-based screening in a municipality after a primary school outbreak of the SARSCoV-2 Alpha variant, the Netherlands, December 2020–February 2021

An outbreak of SARS-CoV-2 Alpha variant (Pango lineage B.1.1.7) was detected at a primary school (School X) in Lansingerland, the Netherlands, in December 2020. The outbreak was studied retrospectively, and population-based screening was used to assess the extent of virus circulation and decelerate transmission. Cases were SARS-CoV-2 laboratory confirmed and were residents of Lansingerland (November 16(th) 2020 until February 22(th) 2021), or had an epidemiological link with School X or neighbouring schools. The SARS-CoV-2 variant was determined using variant PCR or whole genome sequencing. A questionnaire primarily assessed clinical symptoms. A total of 77 Alpha variant cases were found with an epidemiological link to School X, 16 Alpha variant cases linked to the neighbouring schools, and 146 Alpha variant cases among residents of Lansingerland without a link to the schools. The mean number of self-reported symptoms was not significantly different among Alpha variant infected individuals compared to non-Alpha infected individuals. The secondary attack rate (SAR) among Alpha variant exposed individuals in households was 52% higher compared to non-Alpha variant exposed individuals (p = 0.010), with the mean household age, and mean number of children and adults per household as confounders. Sequence analysis of 60 Alpha variant sequences obtained from cases confirmed virus transmission between School X and neighbouring schools, and showed that multiple introductions of the Alpha variant had already taken place in Lansingerland at the time of the study. The alpha variant caused a large outbreak at both locations of School X, and subsequently spread to neighbouring schools, and households. Population-based screening (together with other public health measures) nearly stopped transmission of the outbreak strain, but did not prevent variant replacement in the Lansingerland municipality

Temporal Rewards for Performance Evaluation

Today many formalisms exist for specifying complex Markov chains. In contrast, formalism for specifying the quantitative properties to analyze have remained quite primitive. In this paper a new formalism of temporal rewards that allows complex quantitative properties (including delay type measures) to be expressed in the form of a temporal reward formula. Together, an initial (discrete-time) Markov chain and the temporal reward formula implicitly define an extended Markov chain that allows the determination of the quantitative property by traditional techniques for computing long-run averages. A method to construct the extended chain is given and it is proven that this method leaves long-run averages invariant for atomic (non-temporal) rewards

Performance Evaluation With Temporal Rewards

Today many formalisms exist for specifying complex Markov chains. In contrast, formalisms for specifying rewards, enabling the analysis of long-run average performance properties, have remained quite primitive. Basically, they only support the analysis of relatively simple performance metrics that can be expressed as long-run averages of atomic rewards, i.e. rewards that are deductible directly from the individual states of the initial Markov chain specification. To deal with complex performance metrics that are dependent on the accumulation of atomic rewards over sequences of states, the initial specification has to be extended explicitly to provide the required state information

Temporal Rewards for Performance Evaluation

Today many formalisms exist for specifying complex Markov chains. In contrast, formalism for specifying the quantitative properties to analyze have remained quite primitive. In this paper a new formalism of temporal rewards that allows complex quantitative properties (including delay type measures) to be expressed in the form of a temporal reward formula. Together, an initial (discrete-time) Markov chain and the temporal reward formula implicitly define an extended Markov chain that allows the determination of the quantitative property by traditional techniques for computing long-run averages

Performance prediction and design-space exploration for wafer scanners.

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