Search results for "Model Checking"
showing 10 items of 27 documents
Progress Checking for Dummies
2018
Verification of progress properties is both conceptually and technically significantly more difficult than verification of safety and deadlock properties. In this study we focus on the conceptual side. We make a simple modification to a well-known model to demonstrate that it passes progress verification although the resulting model is intuitively badly incorrect. Then we point out that the error can be caught easily by adding a termination branch to the system. We compare the use of termination branches to the established method of addressing the same need, that is, weak fairness. Then we discuss another problem that may cause failure of catching progress errors even with weak fairness. Fi…
Optimal paths in weighted timed automata
2004
AbstractWe consider the optimal-reachability problem for a timed automaton with respect to a linear cost function which results in a weighted timed automaton. Our solution to this optimization problem consists of reducing it to computing (parametric) shortest paths in a finite weighted directed graph. We call this graph a parametric sub-region graph. It refines the region graph, a standard tool for the analysis of timed automata, by adding the information which is relevant to solving the optimal-reachability problem. We present an algorithm to solve the optimal-reachability problem for weighted timed automata that takes time exponential in O(n(|δ(A)|+|wmax|)), where n is the number of clock…
The Inconsistent Labelling Problem of Stutter-Preserving Partial-Order Reduction
2020
AbstractIn model checking, partial-order reduction (POR) is an effective technique to reduce the size of the state space. Stubborn sets are an established variant of POR and have seen many applications over the past 31 years. One of the early works on stubborn sets shows that a combination of several conditions on the reduction is sufficient to preserve stutter-trace equivalence, making stubborn sets suitable for model checking of linear-time properties. In this paper, we identify a flaw in the reasoning and show with a counter-example that stutter-trace equivalence is not necessarily preserved. We propose a solution together with an updated correctness proof. Furthermore, we analyse in whi…
Bayesian Checking of the Second Levels of Hierarchical Models
2007
Hierarchical models are increasingly used in many applications. Along with this increased use comes a desire to investigate whether the model is compatible with the observed data. Bayesian methods are well suited to eliminate the many (nuisance) parameters in these complicated models; in this paper we investigate Bayesian methods for model checking. Since we contemplate model checking as a preliminary, exploratory analysis, we concentrate on objective Bayesian methods in which careful specification of an informative prior distribution is avoided. Numerous examples are given and different proposals are investigated and critically compared.
Safety Assurance of a High Voltage Controller for an Industrial Robotic System
2020
Abstract Due to the risk of discharge sparks and ignition, there are strict rules concerning the safety of high voltage electrostatic systems used in industrial painting robots. In order to assure that the system fulfils its safety requirements, formal verification is an important tool to supplement traditional testing and quality assurance procedures. The work in this paper presents formal verification of the most important safety functions of a high voltage controller. The controller has been modelled as a finite state machine, which was formally verified using two different model checking software tools; Simulink Design Verifier and RoboTool. Five safety critical properties were specifie…
Formal Analysis and Model Checking of a Group Authentication Protocol by Scyther
2016
Scyther [1] is designed to check the security and vulnerabilities of security protocols. In this paper, we use Scyther to analyze two discrete logarithm problem (DLP) based group authentication protocols proposed in [2]. These two protocols are claimed to satisfy several security requirements, but only part of them have been checked because of the properties and limitations of Scyther. Some positive results have been gained and show that the protocols provide mutual authentication and implicit key authentication and are secure against impersonation attack. An important innovation in this paper is that we have extended the expressing ability of Scyther by giving some reasonable assumption du…
Building a new CTL model checker using Web services
2013
This Computation Tree Logic (CTL) is widely used to capture compositions of reactive systems. Model checking is particularly well-suited for the automated verification of finite-state systems, both for software and for hardware. A CTL model checker tool allows designers to automatically verify that systems satisfy specifications expressed in the language of CTL logic. In this paper we present a new CTL model checker implemented in client-server paradigm. CTL Designer, the client tool, allows an interactive construction of the CTL models as state-transition graphs. Java and C# APIs are provided for programmatic construction of large models. The server part of our tool embeds the core of the …
Verification of JADE Agents Using ATL Model Checking
2015
It is widely accepted that the key to successfully developing a system is to produce a thorough system specification and design. This task requires an appropriate formal method and a suitable tool to determine whether or not an implementation conforms to the specifications. In this paper we present an advanced technique to analyse, design and debug JADE software agents, using Alternating-time Temporal Logic (ATL) which is interpreted over concurrent game structures, considered as natural models for compositions of open systems. In development of the proposed solution, we will use our original ATL model checker. In contrast to previous approaches, our tool permits an interactive or programma…
Towards a Formal Analysis of MQtt Protocol in the Context of Communicating Vehicles
2017
International audience; The paper presents a formal approach to model, analyze, and verify a variant of Message Queue Telemetry Transport protocol (MQtt), dedicated to communicating vehicles (MQtt-CV) that send collected data to automotive infrastructures(subscribers). Our formal approach is based on Promela language and its system verification tool, the model checker SPIN. We propose a slight modification of MQtt protocol to reduce the big volume of data collected and sent by vehicles to infrastructures. Indeed, in the original version of MQtt protocol, when a broker receives data from publishers, it sends them directly to its subscribers without any filtration. As consequence, subscribers…
Deciding properties of integral relational automata
1994
This paper investigates automated model checking possibilities for CTL* formulae over infinite transition systems represented by relational automata (RA). The general model checking problem for CTL* formulae over RA is shown undecidable, the undecidability being observed already on the class of Restricted CTL formulae. The decidability result, however, is obtained for another substantial subset of the logic, called A-CTL*+, which includes all ”linear time” formulae.