Rational double points on Enriques surfaces

We classify,up to some lattice-theoretic equivalence,all possible configurations of rational double points that can appear on a surface whose minimal resolution is a complex Enriques surface.

Dynamic Multi-Attribute Decision-Making Method with Double Reference Points and Its Application

To better reflect the psychological behavior characteristics of loss aversion,this paper builds a double reference point decision making method for dynamic multi-attribute decision-making(DMADM)problem,taking bottom-line and target as reference pints.First,the gain/loss function is given,and the state is divided according to the relationship between the gain/loss value and the reference point.Second,the attitude function is constructed based on the results of state division to establish the utility function.Third,the comprehensive utility value is calculated as the basis for alternatives classification and ranking.Finally,the new method is used to evaluate the development level of smart cities.The results show that the new method can judge the degree to which the alternatives meet the requirements of the decision-maker.While the new method can effectively screen out the unsatisfactory alternatives,the ranking results of other alternatives are consistent with those of traditional methods.

DOUBLE HIGH ORDER S－BREAKING BIFURCATION POINTS AND THEIR NUMERICAL DETERMINATION

We consider double high order S-breaking bifurcation points of two-Parameter dependent nonlinear problems with Z_2×Z_2-symmetry. Because of the underlying symmetry we could propose some regular extended systems to determine double high order S-breaking bifurcation points. and we could also show that there exist two quadratic pitchfork bifurcation point paths passing through the point being considered.

Double coupled fixed point for multi-valued mixed increasing operators in ordered Banach spaces

In this paper, a new concept of double coupled fixed point for multi-valued mixed increasing operators is given and some new double coupled fixed point theorems for multi-valued mixed increasing operators in ordered Banach spaces are also given. These results extend and generalize some results of Huang and Fang.

A SPLITTING ITERATION METHOD FOR DOUBLE X_0-BREAKING BIFURCATION POINTS

A splitting iteration method is proposed to compute double X0-breaking bifurcation points. The method will reduce the computational work and storage, it converges linearly with an adjustable speed. Numerical computation shows the effectiveness of splitting iteration method.

DOUBLE S-BREAKING CUBIC TURNING POINTS AND THEIR COMPUTATION

In the paper we are concerned with double S-breaking cubic turning points of two-parameter nonlinear problems in the presence of Z(2)-symmetry. Three extended systems are proposed to determine double S-breaking cubic turning points. We show that there exist two kinds of singular point path passing through double S-breaking cubic turning point, One is the simple quadratic turning point path, the other is the pitchfork bifurcation point path.

SINGULARITIES OF SPHERICAL FOUR-BAR MOTION

The link curve of a spherical four bar mechanism can be separated into two branches. The condition that the double points of the curve must satisfy is given. The double points may be the double points of either branch, or the intersection points of the two branches.

Poroelastic solid flow with double point material point method

This paper presents the numerical modelling of one and two-dimensional poroelastic solid flows,using the material point method with double point formulation.The double point formulation offers the convenience of allowing for transitions in the flow conditions of the liquid,between free surface flow and groundwater flow.The numerical model is validated by comparing the solid flow velocity with the analytical solution.The influence of the Young＇s modulus on the solid flow velocity is discussed for both one and two-dimensional analysis cases.The effect of the shape of the two-dimensional solid is investigated.It is shown that the solid stiffness has an effect on the poroelastic flow velocity,due to swelling and bending for the one and two-dimensional cases,respectively.The shape is found to be an important factor on the flow velocity of the poroelastic solid.

On the classification of OADP varieties

The main purpose of this paper is to show that OADP varieties stand at an important crossroad of various main streets in different disciplines like projective geometry,birational geometry and algebra.This is a good reason for studying and classifying them.Main specific results are:(a) the classification of all OADP surfaces (regardless to their smoothness);(b) the classification of a relevant class of normal OADP varieties of any dimension,which includes interesting examples like lagrangian grassmannians.Following Pirio and Russo (Comm Math Helv,to appear),the equivalence of the classification in (b) with the one of quadro-quadric Cremona transformations and of complex,unitary,cubic Jordan algebras are explained.

Gorenstein Q-homology projective planes

We present the complete list of all singularity types on Gorenstein Q-homology projective planes,i.e.,normal projective surfaces of second Betti number one with at worst rational double points.The list consists of 58 possible singularity types,each except two types supported by an example.

MULTIPLE POSITIVE SOLUTIONS OF BOUNDARY VALUE PROBLEMS FOR QUASILINEAR DIFFERENTIAL EQUATIONS

We consider the boundary value problem for the second order quasilinear differential equationwhere f is allowed to change sign, φ(v) = \v\p-2v, p > 1. Using a new fixed point theorem in double cones, we show the existence of at least two positive solutions of the boundary value problem.