Researchers have suggested viewing interactive system design as the refinement of an abstract user-task model into an object-oriented interaction model[1, 14]. Inherent in this view is a shift in the nature of the behavior being modeled. We explore the manifestations of such a shift by critically analyzing properties of the forms used to represent task and interaction models. The analysis enabl...

level Concrete level refinement −−−−−−→ ConnectToServer Details used to establish the connection abstraction ←−−−−−− Formalisation of abstraction Let σ : A → P(B) be a substitution. Abstract level Concrete level σ(L) = {w ∈ A | σ(w) ∩ L '= ∅} abstraction ←−−−−−− L ⊆ B 5/29 Adding time to the picture Timed refinement refinement −−−−−−→ Abstract level Concrete level abstraction ←−−−−−− ConnectToS...

Automated abstraction is widely recognized as a key method for computer-aided verification of hardware and software. In this paper, we describe the evolution of counterexample-guided refinement and other iterative abstraction refinement techniques.

Our approach integrates three mechanisms needed to model and animate deformable objects: controlling mechanisms, geometric surface deformation, and mesh refinement. Most approaches focus either modeling physically correct behavior or alternative representations for deformable models. This results in a set of method specific algorithms that best represents a particular class of deformable object...

Railway signalling systems have received a great deal of attention from the formal methods community. One reason for this is that the domain is relatively accessible; another is that the safety analyses to be undertaken are often highly parallelizable. In this paper we describe a ‘cloud interface’ for the refinement checker, Failures Divergences Refinement (FDR), which has been motivated and va...

This work presents a mesh refinement indicator based on entropy variables, with an application to the compressible Navier-Stokes equations. The entropy variables are shown to satisfy an adjoint equation, an observation that allows recent work in adjoint-based error estimation to be leveraged in constructing a relatively cheap but effective adaptive indicator. The output associated with the entr...

This paper discusses how different ways of introducing “extra” actions in refinement (such as weak refinement, action refinement, stuttering steps) relate to the underlying refinement relations used (e.g. trace refinement, failures refinement). In particular, we aim to show how the choices in those two dimensions are interdependent. The paper is not intended to be polemic (“my formalism/refinem...

Propagation of transient mechanical waves in porous media is numerically investigated in 1D. The framework is the linear Biot’s model with frequency-independant coefficients. The coexistence of a propagating fast wave and a diffusive slow wave makes numerical modeling tricky. A method combining three numerical tools is proposed: a fourth-order ADER scheme with time-splitting to deal with the ti...

In the standard testing theory of DeNicola-Hennessy one process is considered to be a refinement of another if every test guaranteed by the former is also guaranteed by the latter. In the domain of web services this has been recast, with processes viewed as servers and tests as clients. In this way the standard refinement preorder between servers is determined by their ability to satisfy client...

Numerical evolution of the spherically symmetric, massive KleinGordon field is presented using a new adaptive mesh refinement (AMR) code with fourth order discretization in space and time, along with compactification in space. The system is non-interacting thus the initial disturbance is entirely radiated away. The main aim is to simulate its propagation until it vanishes near I . By numerical ...