268 research outputs found
Sigref ā A Symbolic Bisimulation Tool Box
We present a uniform signature-based approach to compute the most popular bisimulations. Our approach is implemented symbolically using BDDs, which enables the handling of very large transition systems. Signatures for the bisimulations are built up from a few generic building blocks, which naturally correspond to efficient BDD operations. Thus, the definition of an appropriate signature is the key for a rapid development of algorithms for other types of bisimulation.
We provide experimental evidence of the viability of this approach by presenting computational results for many bisimulations on real-world instances. The experiments show cases where our framework can handle state spaces efficiently that are far too large to handle for any tool that requires an explicit state space description.
This work was partly supported by the German Research Council (DFG) as part of the Transregional Collaborative Research Center āAutomatic Verification and Analysis of Complex Systemsā (SFB/TR 14 AVACS). See www.avacs.org for more information
On the properties of discs around accreting brown dwarfs
We present a grid of models of accreting brown dwarf systems with
circumstellar discs. The calculations involve a self-consistent solution of
both vertical hydrostatic and radiative equilibrium along with a sophisticated
treatment of dust sublimation. We have simulated observations of the spectral
energy distributions and several broadband photometric systems. Analysis of the
disc structures and simulated observations reveal a natural dichotomy in
accretion rates, with \logmdot 9 and 9 classed as extreme and
typical accretors respectively. Derivation of ages and masses from our
simulated photometry using isochrones is demonstrated to be unreliable even for
typical accretors. Although current brown dwarf disc candidate selection
criteria have been shown to be largely reliable when applied to our model grid
we suggest improved selection criteria in several colour indices. We show that
as accretion rates increase brown dwarf disc systems are less likely to be
correctly identified. This suggests that, within our grid, systems with higher
accretion rates would be preferentially lost during brown dwarf target
selection. We suggest that observations used to assert a
relationship may contain an intrinsic selection bias.Comment: 13 figures, 2 tables, 2 appendices and 25 pages. Accepted for
publication in MNRA
Proceedings of the 22nd Conference on Formal Methods in Computer-Aided Design ā FMCAD 2022
The Conference on Formal Methods in Computer-Aided Design (FMCAD) is an annual conference on the theory and applications of formal methods in hardware and system verification. FMCAD provides a leading forum to researchers in academia and industry for presenting and discussing groundbreaking methods, technologies, theoretical results, and tools for reasoning formally about computing systems. FMCAD covers formal aspects of computer-aided system design including verification, specification, synthesis, and testing
CUEING: a lightweight model to Capture hUman attEntion In driviNG
Discrepancies in decision-making between Autonomous Driving Systems (ADS) and
human drivers underscore the need for intuitive human gaze predictors to bridge
this gap, thereby improving user trust and experience. Existing gaze datasets,
despite their value, suffer from noise that hampers effective training.
Furthermore, current gaze prediction models exhibit inconsistency across
diverse scenarios and demand substantial computational resources, restricting
their on-board deployment in autonomous vehicles. We propose a novel adaptive
cleansing technique for purging noise from existing gaze datasets, coupled with
a robust, lightweight convolutional self-attention gaze prediction model. Our
approach not only significantly enhances model generalizability and performance
by up to 12.13% but also ensures a remarkable reduction in model complexity by
up to 98.2% compared to the state-of-the art, making in-vehicle deployment
feasible to augment ADS decision visualization and performance
Optimized Temporal Monitors for SystemC
SystemC is a modeling language built as an extension of C++. Its growing popularity and the increasing complexity of designs have motivated research efforts aimed at the verification of SystemC models using assertion-based verification (ABV), where the designer asserts properties that capture the design intent in a formal language such as PSL or SVA. The model then can be verified against the properties using runtime or formal verification techniques. In this paper we focus on automated generation of runtime monitors from temporal properties. Our focus is on minimizing runtime overhead, rather than monitor size or monitor-generation time. We identify four issues in monitor generation: state minimization, alphabet representation, alphabet minimization, and monitor encoding. We conduct extensive experimentation and identify a combination of settings that offers the best performance in terms of runtime overhead
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