In this work, a method for generating external schemas in object oriented databases in the ODMG framework is proposed. External schema generation involves obtaining all the relationships existing between the classes selected to make up an external schema. This generation process is part of an external schema definition system that we are developing, which allows the definition of external schem...

Our aim is to put the partially successful analytic noncovariant approaches to Coulomb gauge QCD on a firm and systematic basis. To this end, we develop a generating functional approach to the equal-time correlation functions. In fact, such a functional is given in terms of the vacuum wave functional, however, in a perturbative expansion of the equal-time correlation functions, the vacuum wave ...

In this paper, we study the instability of the zero solution to a nonlinear differential equation with variable delay. By using the Lyapunov functional approach, some sufficient conditions for instability of the zero solution are obtained. Keywords—Instability, Lyapunov-Krasovskii functional, delay differential equation, fifth order.

In this paper, we overview the recently introduced general framework of Description Logic Based Dynamic Systems, which leverages Levesque’s functional approach to model systems that evolve the extensional part of a description logic knowledge base by means of actions. This framework is parametric w.r.t. the adopted description logic and the progression mechanism. In this setting, we discuss ver...

Many psychologists collect multitrait-multimethod (MTMM) data to assess the convergent and discriminant validity of psychological measures. In order to choose the most appropriate model, the types of methods applied have to be considered. It is shown how the combination of interchangeable and structurally different raters can be analyzed with an extension of the correlated trait-correlated meth...

In this paper the construction of a model that represents the behavior of an Electric Vehicle is described. Both the mechanical and the electric traction systems are represented using Multi-Bond Graph structural approach suited to model large scale physical systems. Then the model of the controllers, represented with a functional approach, is included giving rise to an integrated model which ex...

A statistical mechanical expression for the anisotropic surface (anchoring) en~ ergy of a nematic polymer melt is derived m the molecular field approximation using the density functional approach It is shown that this

In this paper, we present an approach to obstacle avoidance for a group of unmanned vehicles moving in formation. The goal of the group is to move through a partially unknown environment with obstacles and reach a destination while maintaining the formation. We address this problem for a class of dynamic unicycle robots. Using Inputto-State Stability we combine a general class of formationkeepi...

This paper focuses on the delay-dependent robust stability of linear neutral delay systems. The systems under consideration are described by functional differential equations, with norm bounded time varying nonlinear uncertainties in the “state” and norm bounded time varying quasi-linear uncertainties in the delayed “state” and in the difference operator. The stability analysis is performed via...

This thesis is two fold. The first part deals with an existence proof of a formal algorithm that takes a narrative discourse and returns its semantic representation in the Event Calculus (EC from now on) [19]. This algorithm uses Discourse Representation Theory, and takes on the form of a translation from Discourse Representation Structures to Scenarios and Integrity Constraints in EC. The seco...