Xiaoqing Jin

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Industrial control systems are often hybrid systems that are required to satisfy strict performance requirements. Verifying designs against requirements is a difficult task, and there is a lack of suitable open benchmark models to assess, evaluate, and compare tools and techniques. Benchmark models can be valuable for the hybrid systems research community,(More)
A significant challenge to the formal validation of software-based industrial control systems is that system requirements are often imprecise, non-modular, evolving, or even simply unknown. We propose a framework for mining requirements from the closed-loop model of an industrial-scale control system, such as one specified in the Simulink modeling language.(More)
Suitable open benchmark models help to assess, evaluate, and compare tools and techniques, help the research community understand the nature and complexity of the problems facing industrial practitioners, and also help industry to embrace new techniques. We present two benchmark models from the automotive powertrain control domain. Each model has a unique(More)
State-space exploration is an essential first step in many modeling and analysis problems. Its goal is to find and store all the states reachable from the initial state(s) of a discrete-state high-level model described, for example, using pseudocode or Petri nets. The state space can then be used to answer important questions, such as “Is there a dead(More)
Techniques for testing cyberphysical systems (CPS) currently use a combination of automatic directed test generation and random testing to find undesirable behaviors. Existing techniques can fail to efficiently identify bugs because they do not adequately explore the space of system behaviors. In this paper, we present an approach that uses the rapidly(More)
Due to their appealing conceptual simplicity and availability of computer tools for their analysis, Petri nets are widely used to model discrete-event systems in many areas of engineering. However, the computational resources required to carry out the analysis of a Petri net model are often enormous, hindering their practical impact. In this survey, we(More)
Safety verification of embedded systems modeled as hybrid systems can be scaled up by employing simulation-guided reach set over-approximation techniques. Existing methods are either applicable to only restricted classes of systems, overly conservative, or computationally expensive. We present new techniques to compute a locally optimal bloating factor(More)
INTRODUCTION Structural MRI has long been used to characterize local morphological features of the human brain. Coordination patterns of the local morphological features among regions, however, are not well understood. Here, we constructed individual-level morphological brain networks and systematically examined their topological organization and long-term(More)
Resting-state functional magnetic resonance imaging (R-fMRI) has been intensively used to assess alterations of inter-regional functional connectivity in patients with stroke, but the regional properties of brain activity in stroke have not yet been fully investigated. Additionally, no study has examined a frequency effect on such regional properties in(More)
Requirements of cyberphysical systems (CPS) can be rigorously specified using Signal Temporal Logic (STL). STL comes equipped with semantics that are able to quantify how robustly a given signal satisfies an STL property. In a setting where signal values over the entire time horizon of interest are available, efficient algorithms for offline computation of(More)