The semi-geostrophic equations are used in meteorology. They appear as a variant of the two-dimensional Euler incompressible equations in vorticity form, where the Poisson equation that relates the stream function and the vorticity field is just replaced by the fully non linear elliptic Monge-Ampère equation. This work gathers new results concerning the semi-geostrophic equations: Existence and...

In this article, a generalization of a Kakutani-Fan fixed point theorem for multi-valued mappings in Banach spaces is proved under weaker upper semi-continuity condition and it is further applied to derive a generalized version of Krasnoselskii’s fixed point theorem and some nonlinear alternatives of Leray-Schauder type for multi-valued closed mappings in Banach spaces. RESUMEN En este artículo...

A new method is presented for numerically capturing a moving interface of arbitrary dimension and codimension. The method is named the ‘local level set method’, since it localizes the level set method near the interface to significantly reduce the computational expense of the level set method. Following the framework of the level set method, an interface is implicitly represented as the zero le...

Abstract. Let f(X) = (XC + D )M(XC + D) − G be a given nonlinear Hermitian matrix-valued function with M = M∗ and G = G∗, and assume that the variable matrix X satisfies the consistent linear matrix equation XA = B. This paper shows how to characterize the semi-definiteness of f(X) subject to all solutions of XA = B. As applications, a standard method is obtained for finding analytical solution...

By interpreting ‘p is impossible’ by ‘p is selfcontradictory’, and ‘p is always’ by ‘not p is self-contradictory’, this paper studies which of the three-valued systems of Łucasiewicz, Gödel, Kleene, Bochvar, and Post, do verify the Aristotle’s principles of Non-Contradiction (NC), and Excluded-Middle (EM). Keywords— Systems of three-valued logic, Non-Contradiction, Excluded-Middle.

In this article we define the inverse limit of an inverse sequence (X1, f1), (X2, f2), (X3, f3), . . . where each Xi is a compact Hausdorff space and each fi is an upper semi-continuous function from Xi+1 into 2i . Conditions are given under which the inverse limit is a Hausdorff continuum and examples are given to illustrate the nature of these inverse limits.

We consider a generalized semi-infinite programming problem (GSIP) with one semi-infinite constraint where the index set depends on the variable to be minimized. Keeping in mind the integral global optimization method of Zheng & Chew and its modifications we would like to outline theoretical considerations for determining coarse approximations of a solution of (GSIP) via global optimization of ...

The Linearization of Nonlinear feedback shift registers (NFSRs) is to find their state transition matrices. In this paper, we investigate the linearization multi-valued NFSRs by considering it as a logical network via a semi-tensor product approach. A new state transition matrix is found for an multi-valued NFSR, which can be simply computed from the truth table of its feedback function, and th...