10 articles in this issue
Virginia De Cicco, Giuseppe Marino
A composition operator is a linear operator CT on a subspace of KX by a point transformation T on a set X (where K denotes the scalar field) by the formula CT f(x) :=f ° T(x). We give some necessary and/or sufficient conditions under which the map T... see more
Chin-Mei Fu, Hung-Lin Fu
In this paper, we mainly solve the intersection problem of three distinct latin squares of two different types: LS and ILS, and the intersections of ICLS and CLSH can be obtained by a similar way.
Paolo Maroscia
We prove some new results concerning the Hilbert function of a finite set of points in general position in P2, with assigned multiplicities. In particular we answer a question raised by E. Davis and A. V. Geramita.
Sebastiano Pennisi
In a Minkowski space V, consideration is given to the tensor-valued isotropic functions of an arbitrary number of tensors of which one is a time-like vector Ua and another is a symmetric tensor Aaß, such that Âaß, its space-space part orthogonal to ... see more
Basilio Messano
It is given a non trivial example of nonempty subset I of C0([0,1]2) such that: whatever F ? I be, for the pair ([0,1]2,F) the successive approximations method converges globally (i.e. For each P ? [0,1]2 the sequence (Fn(P))n? N converges to a fi... see more
Danut Marcu
In this note, we prove the conjecture of Abelson and Rosenberg, on the maximal degree of balance of a graph, with n vertices, and we characterize these maximal graphs.
Rosa Stangarone, Antonio Terrusi
A classic theorem by B. Segre [4], and G. Tallini, [6], states that in a finite desarguesian plane of order q no complete q-arc exists. This result can not be extended to any non desarguesian plane ([1],[2],[3]). In this paper we consider a non desargues... see more
Jan Persson
The Cauchy problem for a non-linear system of regularized measure differential equations is studied. It is proved that the solutions of the regularized problems converges to a solution of an integral equation involving measures. In general this equation d... see more
Alfonso Villani
See directly the article.
Snezhana G. Hristova, Drumi D. Bainov
In the paper a monotone-iterative method for approximate finding a couple of minimal and maximal quasisolutions of the periodic problem for a system of integro-differential equations of Volterra type is justified.