This paper discusses highly general mechanisms for specifying the refinement of a real-time system as a collection of lower level parallel components that preserve the timing and functional requirements of the upper level specification. These mechanisms are discussed in the context of ASTRAL, which is a formal specification language for real-time systems. Refinement is accomplished by mapping a...

Real-time systems often have to be able to cope with an unbounded number of components. For example, a real-time operating system scheduler manages arbitrarily many threads or a bus system copes with arbitrarily many connected devices. Such systems can be characterized as parameterized systems. The number of (homogeneous) components is the parameter of these systems. This makes their formal ver...

Bargaining with reading habit is no need. Reading is not kind of something sold that you can take or not. It is a thing that will change your life to life better. It is the thing that will give you many things around the world and this universe, in the real world and here after. As what will be given by this real time systems specification verification and analysis, how can you bargain with the...

The main objective of this paper is to present an approach to accomplish verification in the early design phases of a system, which allows us to make the system verification easier, specifically for those systems with timing restrictions. For this purpose we use RT-UML sequence diagrams in the design phase and we translate these diagrams into timed automata for performing the verification by us...

In real-time systems, correctness depends on the time at which events occur. Examples of real-time systems include timed protocols and many embedded system controllers. Timed automata are an extension of finite-state automata that include real-valued clock variables used to measure time. Given a timed automaton, an equivalent finite-state region automaton can be constructed, which guarantees de...

This paper presents a verification technique for dense-time MTL based on discretization. The technique reduces the validity problem of MTL formulas from dense to discrete time, through the notion of sampling invariance, introduced in previous work [FR06]. Since the reduction is from an undecidable problem to a decidable one, the technique is necessarily incomplete, so it fails to provide conclu...

Biometrics authentication has been gaining popularity among the industries that highly incorporate securities in their daily activities. Signature verification is one of the biometrics authentication techniques which has been used for years and publicly accepted. The ease of use of signature verification coupled with lower cost and technology advances in tablet technologies, signature verificat...

Counterexamples for property violations have a number of important applications like supporting thedebugging of erroneous systems and verifying large systems via counterexample-guided abstraction refinement.In this paper, we propose the usage of minimal critical subsystems of discrete-time Markov chains and Markovdecision processes as counterexamples for violated ω-regular propertie...

To support top-down design of distributed real-time systems, a framework of mixed terms has been incorporated in the veriication system PVS. Programs and assertional speciications are treated in a uniform way. We focus on the timed behaviour of parallel composition and hiding, presenting several alternatives for the deenition of a deno-tational semantics. This forms the basis of compositional p...