Let Sr be the blow-up of P 2 in r general points, i.e., a smooth Del Pezzo surface of degree 9 − r. For r ≤ 7, we determine the quadratic equations defining its Cox ring explicitly. The ideal of the relations in Cox(S8) is calculated up to radical. As conjectured by Batyrev and Popov, all the generating relations are quadratic.

The type II1 unprojection is, by definition, the generic complete intersection type II unprojection, in the sense of [P] Section 3.1, for the parameter value k = 1, and depends on a parameter n ≥ 2. Our main results are the explicit calculation of the linear relations of the type II1 unprojection for any value n ≥ 2 (Theorem 3.16) and the explicit calculation of the quadratic equation for the c...

in this paper, we introduce and study fuzzy variational-like inclusion, fuzzy resolvent equation and $h(cdot,cdot)$-$phi$-$eta$-accretive operator in real  uniformly smooth banach spaces. it is established that fuzzy variational-like inclusion is equivalent to a fixed point problem as well as to a fuzzy resolvent equation. this equivalence is used to define an iterative algorithm for solving fu...

It is shown that the set of all paraperspective images with arbitrary reference point and the set of aane images of a 3-D object are identical. Consequently, all uncalibrated paraper-spective images of an object can be constructed from a 3-D model of the object by applying an aane transformation to the model and every aane image of the object represents some uncalibrated paraperspective image o...

The Hyers–Ulam–Rassias stability of the conditional quadratic functional equation of Pexider type f (x+y)+f (x−y) = 2g(x)+2h(y), x ⊥ y is proved where ⊥ is the orthogonality in the sense of Rätz.

First, the quadratic functional equation of Pexider type will be solved. By applying this result, we will also solve some functional equations of Pexider type which are closely associated with the quadratic equation.

in this paper, we solve the quadratic $alpha$-functional equations $2f(x) + 2f(y) = f(x + y) + alpha^{-2}f(alpha(x-y)); (0.1)$ where $alpha$ is a fixed non-archimedean number with $alpha^{-2}neq 3$. using the fixed point method and the direct method, we prove the hyers-ulam stability of the quadratic $alpha$-functional equation (0.1) in non-archimedean banach spaces.

aSchool of Science, Beijing University of Posts and Telecommunications, Beijing 100876, People’s Republic of China; bCollege of Mathematics and Statistics, Hebei University of Economics and Business, Shijiazhuang 050061, People’s Republic of China; cKey Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, People’s Republic...

In an earlier work [Pop and Stancu Minasian, 2008], we proposed a method of solving the fully fuzzified linear fractional programming (FFLFP) problem. In this paper, we propose another method of solving the FFLFP problem. First, analogically using the Charnes-Cooper method, we transform the linear fractional programming problem into a linear one. Next, problem of maximizing a function with tria...

In the present paper we outline the stochastic limit approach to superfluidity. The Hamiltonian describing the interaction between the Bose condensate and the normal phase is introduced. Sufficient in the stochastic limit condition of superfluidity is proposed. Existence of superfluidity in the stochastic limit of this system is proved and the non– linear (quadratic) equation of motion describi...