Przeglądaj Rocznik Naukowo-Dydaktyczny. Prace Matematyczne według tytułu
Wyświetlanie pozycji 1-20 z 230
-
An alternative Cauchy equation almost everywhere
(2000)Let (S, +) be a commutative semigroup and let ζ be a proper left translation invariant σ-ideal in S. Suppose that f : S → R satisfies |f(x + y)| = |f(x) + f(y)| Ω(ζ)-almost everywhere in S x S. We prove that there exists, ... -
Approximation by a nonlinear convolution operator in modular function spaces
(2000)There is investigated a nonlinear convolution operator Tf = K*f + Pf in modular function spaces L[0][p](G), with application to approximation of functions f in L[0][p](G). -
Bernstein-Doetsch-type results for general functional inequalities
(2000)In this paper certain functional inequalities are investigated whose solutions are shown to be convex provided that they are locally bounded from above. The results so obtained generalize the classical result of Bernstein ... -
Boundary properties of solutions of the iterated Helmholtz equation
(2000)Some theorems about boundary properties of solutions of the equation (Δ - c[2])[2]u(x, y) = 0 in Holder spaces are given. This is a continuation of E. Wachnicki’s study of the above equation, cf. [6]. Similar theorems ... -
The characterization of the indicator plurality function
(1998)The characterization of the rational and real indicator plurality function in the sense of M. F. S. Roberts is obtained. The answer to M. F. S. Roberts’ question is presented. -
Characterization of transformed linear functions via shift invariances
(2000)Transforms of linear functions in two variables are characterized via translation like composite functional equations on restricted domain, under regularity assumptions of C[1] type. -
Comments on a definition of entropy
(1979) -
Concave itération semigroups of Jensen set-valued functions
(1999)Let S be a closed convex cone such that int S ≠ 0 in a real separable Banach space. A necessary and sufficient condition is given under which a family {F[t] : t ≥ 0} of set-valued functions F[t] : S -> cc(S) is a concave ... -
Connections between Hyers and Lyapunov stability of the ordinary differential equations
(1997)We consider two kinds of stability of the differential equation x' = f(t, x) where f : R[2] —> R is a continuous function, Lipschitzian with respect to the second variable. We prove that the Hyers stability implies the ... -
Convex set-valued functions on (0, oo) and their conjugate
(1998)Let (Ω,Σ,μ) be a σ-finite space and Υ be a Banach space. It is shown that if F : (0,oo) → cl(Y) is a convex continuous set-valued function, then ∫[Ω]y{F°x/y)dμ ⊂ ∫[Ω]ydμF(∫[Ω]xdμ/∫[Ω]ydμ) for all positive p-integrable ... -
A couple of functional equations applied to utility theory
(2000)We show how characterizations of separable and additive representations of rank-dependent expected utility and of rank- independent expected utility lead to the functional equation f(v) = f(vw) + f(g-1[g(v)q(w)]) (v ϵ ... -
Decompositions of bioperands
(1985) -
DeSitter distances in Hilbert spaces
(2000)All 2-point invariants of an arbitrary DeSitter manifold are determined without any regularity assumption, especially those which are additive on geodesics. -
Dido’s functional equation revisited
(2000)