VIEWS ON THE CONCEPT OF FINANCIAL POLICY AND ITS MANIFESTATION

The present study proposes an analysis of the main views expressed in the literature on financial policy, as well as the shaping of our own, clear and comprehensive vision, regarding the content of this concept. The main objective of our research is to clarify the content of the financial policy concept, so that this policy may be effectively used in the service of overall development of our economy and society. Reaching such an objective has implied the research of a vast existing literature on the field, in the country as well as abroad, observing a vast variety of understandings regarding the meaning of the concept itself, the objectives stated within the financial policy as well as the main approaches (ways to follow) for achieving these objectives. Of course the achievement of such a research is not possible without a meaningful analysis of the principles expressed in this field's literature. In relation to this matter we can see that each author has his own conception regarding the subject under review. These expressed conceptions are, in turn, based on previous research in the analyzed area. The accelerated dynamism proved by the evolution of our economy and society in this stage shows us that through the financial policy, outlined both at a micro and a macroeconomic level, clear fundamental objectives must be formulated that should be possible to achieve by partial objectives (sequential), practical methods and procedures being adapted to them. Our research is at the present stage, a theoretical and methodological one. It is based on the comparisons we make between the views expressed in the studies of different authors, trying to draw the "red line" of these views and observing the fundamental meaning given to the financial policy concept. We express our conviction that a clear conceptual expression of the financial policy notion comes to the rescue of the general management (macro and microeconomic) facilitating the process of adopting the most appropriate decisions for achieving the objectives set by the financial policy. The result of our research is represented by the formulation of a clear and comprehensive concept concerning the financial policy. Removing ambiguities in formulating the concept under review as well as in the means of achieving the formulated objectives is for the benefit of achieving the monetary, financial and budgetary balance at a macroeconomic level, which is the foundation for promoting some beneficial financial policies at a microeconomic level.financial policy, financial policy elements, investment policy, financing policy, dividend policy, evolution

A linear domain decomposition method for partially saturated flow in porous media

The Richards equation is a nonlinear parabolic equation that is commonly used for modelling saturated/unsaturated flow in porous media. We assume that the medium occupies a bounded Lipschitz domain partitioned into two disjoint subdomains separated by a fixed interface $\Gamma$. This leads to two problems defined on the subdomains which are coupled through conditions expressing flux and pressure continuity at $\Gamma$. After an Euler implicit discretisation of the resulting nonlinear subproblems a linear iterative ($L$-type) domain decomposition scheme is proposed. The convergence of the scheme is proved rigorously. In the last part we present numerical results that are in line with the theoretical finding, in particular the unconditional convergence of the scheme. We further compare the scheme to other approaches not making use of a domain decomposition. Namely, we compare to a Newton and a Picard scheme. We show that the proposed scheme is more stable than the Newton scheme while remaining comparable in computational time, even if no parallelisation is being adopted. Finally we present a parametric study that can be used to optimize the proposed scheme.Comment: 34 pages, 13 figures, 7 table

An a posteriori error estimate for vertex-centered finite volume discretizations of immiscible incompressible two-phase flow

International audienceIn this paper we derive an a posteriori error estimate for the numerical approximation of the solution of a system modeling the flow of two incompressible and immiscible fluids in a porous medium. We take into account the capillary pressure, which leads to a coupled system of two equations: parabolic and elliptic. The parabolic equation may become degenerate, i.e., the nonlinear diffusion coefficient may vanish over regions that are not known a priori. We first show that, under appropriate assumptions, the energy-type-norm differences between the exact and the approximate nonwetting phase saturations, the global pressures, and the Kirchhoff transforms of the nonwetting phase saturations can be bounded by the dual norm of the residuals. We then bound the dual norm of the residuals by fully computable a posteriori estimators. Our analysis covers a large class of conforming, vertex-centered finite volume-type discretizations with fully implicit time stepping. As an example, we focus here on two approaches: a ''mathematical'' scheme derived from the weak formulation, and a phase-by-phase upstream weighting ''engineering'' scheme. Finally, we show how the different error components, namely the space discretization error, the time discretization error, the linearization error, the algebraic solver error, and the quadrature error can be distinguished and used for making the calculations efficient