Let Z be a finite set of double points in P 1 × P 1 and suppose further that X, the support of Z, is arithmetically Cohen-Macaulay (ACM). We present an algorithm, which depends only upon a combinatorial description of X, for the bigraded Betti numbers of I Z , the defining ideal of Z. We then relate the total Betti numbers of I Z to the shifts in the graded resolution, thus answering a special ...

We prove the normality of the limiting distribution of the coefficients of the q-derangement numbers of type B based on the formula of Foata and Han that contains a parameter z. Setting the parameter z to zero, we are led to the case of ordinary q-derangement numbers. For z = 1, we obtain the normality of the distribution of the coefficients of the usual q-derangement numbers of type B.

The new concept of a Z – number has been recently introduced in decision making analysis. This concept is capable of effectively dealing with uncertainty in information about a decision. As this concept is relatively new in fuzzy sets, its underlying theoretical aspects have not been established yet. In this paper, a multi-layer methodology for ranking Z – numbers is proposed for the first time...

In this paper, we first give a new q-analogue of the Lah numbers. Then we show the irreducible factors of the q-Lah numbers over Z.

Many nonlinear systems can be modeled by uncertain linear-in-parameter models. In this paper, the uncertainty parameters are the Z number coe¢ cients. We use dual fuzzy equations as the models for the uncertain nonlinear systems. The solutions of these fuzzy equations are the controllers when the desired references are regarded as the outputs. The conditions of controllability are proposed. Two...

Traditional [0, 1]-based fuzzy sets were originally invented to describe expert knowledge expressed in terms of imprecise (“fuzzy”) words from natural language. To make this description more adequate, several generalizations of the traditional [0, 1]-based fuzzy sets have been proposed, among them type-2 fuzzy sets and Z-numbers. The main objective of this paper is to study the relation between...

In 1987 Paul Erdős asked me if the Cayley graph defined on Z by a lacunary sequence has necessarily a finite chromatic number. Below is my answer, delivered to him on the spot but neverpublished, and some additional remarks. The key is the interpretation of the question in terms of return times of dynamical systems. 1 The Cayley graph ZΛ 1.1 Let Λ ⊂ N. By definition, the Cayley graph ZΛ is the ...

In this article, we define the set H of quaternion numbers as the set of all ordered sequences q = 〈x, y,w, z〉 where x,y,w and z are real numbers. The addition, difference and multiplication of the quaternion numbers are also defined. We define the real and imaginary parts of q and denote this by x = R(q), y = I1(q), w = I2(q), z = I3(q). We define the addition, difference, multiplication again...