On closed classes of quasilinear functions

On Closed Sets of Relational Constraints and Classes of Functions Closed under Variable Substitutions

Pippenger’s Galois theory of finite functions and relational constraints is extended to the infinite case. The functions involved are functions of several variables on a set A and taking values in a possibly different set B, where any or both of A and B may be finite or infinite.

study of hash functions based on chaotic maps

توابع درهم نقش بسیار مهم در سیستم های رمزنگاری و پروتکل های امنیتی دارند. در سیستم های رمزنگاری برای دستیابی به احراز درستی و اصالت داده دو روش مورد استفاده قرار می گیرند که عبارتند از توابع رمزنگاری کلیددار و توابع درهم ساز. توابع درهم ساز، توابعی هستند که هر متن با طول دلخواه را به دنباله ای با طول ثابت تبدیل می کنند. از جمله پرکاربردترین و معروف ترین توابع درهم می توان توابع درهم ساز md4, md...

On Sandwich theorems for certain classes of analytic functions

The purpose of this present paper is to derive some subordination and superordination results for certain analytic functions in the open unit disk. Relevant connections of the results, which are presented in the paper, with various known results are also considered.

On Pre-θ-Open Sets and Two Classes of Functions

Size functions of subgeometry-closed classes of representable combinatorial geometries

Let exq(G; n) be the maximum number of points in a rank-n geometry (simple matroid) that is representable over GF (q) and that has no restriction isomorphic to the geometry G. We find exq(G; n) for several infinite families of geometries G, and we show that if G is a binary affine geometry, then lim n→∞ ex2(G; n) 2n − 1 = 0.