A Theory of Sampling for Continuous-time Metric Temporal Logic

This paper revisits the classical notion of sampling in the setting of real-time temporal logics for the modeling and analysis of systems. The relationship between the satisfiability of Metric Temporal Logic (MTL) formulas over continuous-time models and over discrete-time models is studied. It is shown to what extent discrete-time sequences obtained by sampling continuous-time signals capture the semantics of MTL formulas over the two time domains. The main results apply to "flat" formulas that do not nest temporal operators and can be applied to the problem of reducing the verification problem for MTL over continuous-time models to the same problem over discrete-time, resulting in an automated partial practically-efficient discretization technique.Comment: Revised version, 43 pages

A General Framework for Large Scale Systems Development

This paper describes a general framework for the modeling, design, simulation, and prototyping of large scale systems. The framework uses a coherent set of tools that model the system at hand, take a control design and analyze, verify, and simulate it; and then can generate code that can be run in a target real-time software platform in the physical system. The paper emphasizes the specification language SHIFT and the simulation tools used by the framework. We present the development of the Automated Highway System as an example. 1 Introduction Large engineering systems, such as automated highway systems (AHS), autonomous vehicle systems (AVS), material handling systems, air traffic management systems (ATMS) face the challenge of providing reliable services using scarce resources. Clients of such systems demand performance, safety, comfort, and efficiency. The problem is often compounded by physical resources that are saturated, inefficiently utilized, or technologically outdated. In ..

Implementation of the SmartAHS using SHIFT simulation environment

SmartAHS is a specification, simulation, and evaluation framework for modeling, control and evaluation of Automated Highway Systems (AHS). SmartAHS is developed using SHIFT, a new programming language with simulation semantics. This paper discusses the requirements that have led to the development of SmartAHS and SHIFT, summarizes the main characteristics of the SHIFT language, describes the components of the SmartAHS framework and its application methodology. An example --- implementation of a tactical level human driver model --- is presented in detail; it is used as a foundation in the studies and evaluation of the partial automation concepts

Primary Intrarenal Neuroblastoma in A 13-Month-Old Girl Presenting as A Wilms' Tumor with Pulmonary Metastasis

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