The contribution of our paper is to present a mixed finite element method for 4 estimation of the velocity in the optical flow constraint, i.e., an advection equation. The resulting 5 inverse problem is well-known to be undetermined because the velocity vector cannot be recovered 6 from the scalar field advected unless further restrictions on the flow, or motion are imposed. If 7 we suppose, fo...

The Duration Calculus is an interval logic with an additional notion of duration. It became one of the main references of real-time system specification for which it was introduced. From a practical point of view an important challenge is to define automated proof procedures for this calculus. Since the propositional Duration Calculus is undecidable, in this paper we isolate a fragment and we d...

so the CO2 tension can be measured in a gas rather than in a liquid (Campbell and Howell, 1960a). The problem is to achieve this equilibrium before the prevention of its excretion causes the pressure of the CO2 in the blood to rise excessively. A rapid equilibrium will be achieved if a gas mixture is rebreathed which contains enough CO2 to enrich the alveolar gas to approximately the same tensi...

While the concept of mixed-methods research is more usually associated with combining quantitative and qualitative approaches, this paper outlines a study that mixed methods by undertaking qualitative theory testing and derivation when examining the relationship between health promotion theory and hospital nursing practice. Thus, it is concerned with relating the metatheoretical aspects of the ...

A mixed—mode delamination test procedure was developed combining double cantilever beam (DCB) mode I loading and end-notch fixture (ENF) mode II loading on a split unidirectional laminate. By loading with a lever, a single applied load simultaneously produces mode I and mode II bending loads on the specimen. This mixed-mode bending (MMB) test was analyzed using both finite-element procedures an...

where ΓD and ΓN are assumed to partition the boundary of Ω, and ~ν(~x) denotes the outward unit normal from Ω at ~x ∈ ΓN . Additionally we assume that each connected component of ΓN is simply connected. The numerical treatment of (1 3) involves the solution of usually very large indefinite linear equation systems. In this paper we describe a very efficient and practicable iterative method to so...

Various applications in fluid dynamics and computational continuum mechanics motivate the development of reliable and efficient adaptive algorithms for mixed finite element methods. In order to save degrees of freedom, not all but just a selection of finite element domains are refined. Hence the fundamental question of convergence as well as the question of optimality require new mathematical a...