We define a class 3 of topological dynamical systems, which are left invariant by coupled map lattice constructions. ‘fhis class .F has the property that if the coupling of the systems is sufficiently weak and (M, f) contains a hyperbolic set, ‘hen the new system $( M, f) obtained by the coupled map lattice construction has a hyperbolic set too. The coupled map attice construction, map 4, can b...

Weak designs were defined in [10] and are used in constructions of extractors. Roughly speaking, a weak design is a collection of subsets satisfying some near-disjointness properties. Constructions of weak designs with certain parameters are given in [10]. These constructions are explicit in the sense that they require time and space polynomial in the number of subsets. However, the constructio...

For a Boolean function f, let D(f) denote its deterministic decision tree complexity, i.e., minimum number of (adaptive) queries required in worst case in order to determine f. In a classic paper, Rivest and Vuillemin [19] show that any non-constant monotone property P : {0, 1}( n 2) → {0, 1} of n-vertex graphs has D(P) = Ω(n). We extend their result to 3-uniform hypergraphs. In particular, we ...

We deal with Perazzo 3-folds in P4, i.e. hypersurfaces X=V(f)⊂P4 of degree d defined by a homogeneous polynomial f(x0,x1,x2,u,v)=p0(u,v)x0+p1(u,v)x1+p2(u,v)x2+g(u,v), where p0,p1,p2 are algebraically dependent but linearly independent forms d−1 u,v, and g is form u,v d. have vanishing hessian and, hence, the associated graded Artinian Gorenstein algebra Af fails strong Lefschetz Property. In th...

‎In this paper‎, ‎we introduce more general contractions called $varphi $-fixed‎ ‎point point for $(F,varphi‎ ,‎alpha )_{s}$ and $(F,varphi‎ ,‎alpha )_{s}$-‎weak contractions‎. ‎We prove the existence and uniqueness of $varphi $-‎fixed point point for $(F,varphi‎ ,‎alpha )_{s}$ and $(F,varphi‎ ,‎alpha‎‎)_{s}$-weak contractions in complete $b$-metric spaces‎. ‎Some examples are‎ ‎supplied to sup...

We show that the property of sequential compactness for subspaces of R is countably productive in ZF. Also, in the language of weak choice principles, we give a list of characterizations of the topological statement ‘sequentially compact subspaces of R are compact’. Furthermore, we show that forms 152 (= every non-well-orderable set is the union of a pairwise disjoint well-orderable family of d...

In [9] a new class of MV -algebras with product, called LΠqalgebras, has been introduced. In these algebras, the discontinuous product residuation →π defined in [4] is replaced by a continuous approximation of it. These algebras seem to be a good compromise between the need of expressiveness and the need of continuity of connectives. Following a good tradition in many-valued logic (see e.g. [10...

In many real world oscillatory signals, the fundamental component of a signal f(t) might be weak or does not exist. This makes it difficult to estimate instantaneous frequency signal. A traditional approach is apply rectification trick, working with |f(t)| ReLu(f(t)) instead, enhance component. raises an interesting question: what type nonlinear function g:R?R has property that g(f(t)) more pro...