The χ language is a hybrid language for modeling, simulation and verification. As a result of the recently completed formal semantics, the language now consists of a number of orthogonal operators that operate on all process terms, including differential algebraic equations. The same χ model can be used for simulation and verification. Verification is possible after a straightforward syntactica...

If a model structure is not identifiable, then it is not possible to uniquely identify its parameters from measured data. This contribution describes how solvers for differential-algebraic equations (DAE) can be used to examine if a model structure is locally identifiable. The procedure can be applied to both linear and nonlinear systems. If a model structure is not identifiable, it is also pos...

It is known that the satisfiability problem for equations over free partially commutative monoids is decidable but computationally hard. In this paper we consider the satisfiability problem for equations over free partially commutative monoids under the constraint that the solution is a subset of the alphabet. We prove that this problem is NP-complete for quadratic equations and that its unifor...

The aim of this paper is twofold. First, to extend Hodges’ model of relationships between financial planning for retirement with psychosocial variables to predict both objective and subjective measures of financial planning. Second, to apply that model to a representative sample of immigrants in Europe provided by the first wave of SHARE study. Data from 1272 immigrants in Europe were obtained ...

We have recast the problem of t ru th maintenance in a setting of algebraic equations over Boolean lattices. If a method of labeling propositions to justi fy them according to some reasoning agent's constraints of belief happens to conform to the postulates of Boolean lattices, the labeling system can be reformulated as an algebraic equation solving system. A l l t ru th maintenance systems kno...

In this paper we consider the supervisory control problem through language equation solving. The equation solving approach allows to deal with more general topologies and to find a largest supervisor which can be used as a reservoir for deriving an optimal controller. We introduce the notions of solutions under partial controllability and partial observability, and we show how supervisory contr...