A Fenchel–Lagrange Duality Approach for a Bilevel Programming Problem with Extremal-Value Function

In this paper, for a bilevel programming problem (S) with an extremal-value function, we first give its Fenchel–Lagrange dual problem. Under appropriate assumptions, we show that a strong duality holds between them. Then, we provide optimality conditions for (S) and its dual. Finally, we show that the resolution of the dual problem is equivalent to the resolution of a one-level convex minimization problem.     

Necessary and Sufficient Conditions for the Cohen–Macaulayness of Blowup Algebras

In this paper we provide a complete characterization for when the Rees algebra and the associated graded ring of a perfect Gorenstein ideal of grade three are Cohen–Macaulay. We also treat the case of second analytic deviation one ideals satisfying some mild assumptions. In another set of results we give criteria for an ideal to be of linear type. Finally, we describe the equations defining the Rees algebras of certain Northcott ideals.     

RESEARCH ANNOUNCEMENTS The New Necessary and Sufficient Conditions for the Uniformly Continuous and Continuous of Duality Mappings

In[1],Ma shaoqin gave the necessary and sufficient condition for the uniformlycontinuous and continuous of duality mappings.In the note,We give very simplecriteria for the uniformly continuous and continuous of duality mappings.And by[1],the necessary and sufficient conditions for the norm of a real Banach Space to beuniformly Frechet differentiable and Frechet differentiable are described.     

Necessary and Sufficient Conditions for the Strong Consistency of Mnltiple Regression Coefficients Undera Restrictive Condition

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A Perturbation Approach to Vector Optimization Problems: Lagrange and Fenchel–Lagrange Duality

Journal of Optimization Theory and Applications - In this paper, we study a general minimization vector problem which is expressed in terms of a perturbation mapping defined on a product of locally...     

Necessary and Sufficient Convergence Conditions for Algebraic Image Reconstruction Algorithms

Many imaging systems can be modeled by the following linear system of equations Ax = b, （1） where the observed data is b = （b^1…b^M）^T∈K^M and the image is x = （x1…xN）^T∈K^N.     

Necessary and Sufficient Conditions of Existence and Uniqueness of Limit Cycles for a Polynomial System

In this paper, the following polynomial system is discussed:And the necessary and sufficient conditions of existence and uniqueness of limit cyclesare obtained.     

E—matrices and Several Necessary and Sufficient Conditions

AER-x.,Aiscalledanonnegative(nonPositive)matrixifau>O(a,jO(aiirtO),markedA>O(AO(i#j),auO,wecallp(A)=max{IA,l,lA,l'.-.,lAnl},(whereA,,A2,..',A"areeigenva1ueofA)asspectralradiusofA.LemmalIfAe7'.,thenareanonnegativesquarematrxBandapositivenumberksuchthatA=B-kI(whereIistheidentitymatrixofordern).ProofLetbti=…     

The Minimax Equality; Sufficient and Necessary Conditions

The paper produces new versions of the minimax theorem based on original conditions. Moreover, we investigate not only the sufficiency, but also the necessity of such conditions. The proofs are very simple and preclude any topological technique.     

Necessary and Sufficient Optimality Conditions for Regular–Singular Stochastic Differential Games with Asymmetric Information

We consider a class of regular–singular stochastic differential games arising in the optimal investment and dividend problem of an insurer under model uncertainty. The information available to the two players is asymmetric partial information and the control variable of each player consists of two components: regular control and singular control. We establish the necessary and sufficient optimality conditions for the saddle point of the zero-sum game. Then, as an application, these conditions are applied to an optimal investment and dividend problem of an insurer under model uncertainty. Furthermore, we generalize our results to the nonzero-sum regular–singular game with asymmetric information, and then the Nash equilibrium point is characterized.     

RESEARCH ANNOUNCEMENTS Necessary and Sufficient Convergence Conditions for Algebraic Image Reconstruction Algorithms

Many imaging systems can be modeled by the following linear system of equations Ax=b,(1) where the observed data is b=(b~1...b~M)~T∈K~M and the image is x=(x_1…x_N)~T∈K~N.The number field K can be the reals R or the complexes C.The system matrix A=(A_(i,j)) is nonzero and of the dimension M×N matrix.The image reconstruction problem is to reconstruct the     

On Necessary and Sufficient Conditions for the Existence of a Classical Solution of an Inhomogeneous Cauchy–Riemann System

The question of necessary and sufficient conditions for the existence of a classical solution of inhomogeneous Cauchy–Riemann systems in a domain bounded by a piecewise smooth contour is studied. It is proved that the condition of the uniform stronger continuity of that inhomogeneity is a necessary condition, but it is also a sufficient condition if the inhomogeneity belongs to the L₁ space.     

Necessary and Sufficient Conditions for Oscillations of Neutral Delay Equations with Several Positive and Negative Coefficients

In thisPositive and (l)PaPer,we eonsider thenegative eoeffieients ofoseillations of neutral delay equations with、o山 the form·习k-1十玄。,·(卜r。卜全·,·(卜。,))十 XZ夕.、、d一dtJ.。、x(‘一u、)一名h:x(‘一。:)=o,where the eoeffieients and the delays areequation of(1)15non一negative constants.The Charaeteri“tieN(2)F(几):=‘+‘习。‘e一“·卜‘习r,e一‘’,+习。、e一“”一习h:e一‘’一0. ‘二lj一1论一15,1 our main result 19 the following theorem. Theorem All solutions of(l)oseillate if …     

Necessary and Sufficient Condition for Generalized Diagonal Dominance Matrices

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A Sufficient and Necessary Condition for a Solvable Lie Algebra to Be Complete

In this paper,we give a sufficient and neccesary condition under which a solvable Lie algebra is complete.     

On Weak and Strong Kuhn–Tucker Conditions for Smooth Multiobjective Optimization

We consider a smooth multiobjective optimization problem with inequality constraints. Weak Kuhn?CTucker (WKT) optimality conditions are said to hold for such problems when not all the multipliers of the objective functions are zero, while strong Kuhn?CTucker (SKT) conditions are said to hold when all the multipliers of the objective functions are positive. We introduce a new regularity condition under which (WKT) hold. Moreover, we prove that for another new regularity condition (SKT) hold at every Geoffrion-properly efficient point. We show with an example that the assumption on proper efficiency cannot be relaxed. Finally, we prove that Geoffrion-proper efficiency is not needed when the constraint set is polyhedral and the objective functions are linear.     

Dirac’s Type Sufficient Conditions for Hamiltonicity and Pancyclicity

Let G = (V, E) be a any simple, undirected graph on n ≥ 3 vertices with the degree sequence . We consider the class of graphs satisfying the condition where , is a positive integer. It is known that is hamiltonian if θ ≤ δ. In this paper,

A Necessary and Sufficient Condition for Admissibility of Nonnegative Quadratic Estimator

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Sufficient and Necessary Condition for the Measurability of Fallable Fuzzy Sets

Let(X,)be a measurable space,and,=σ-field generated by {x|x∈X},where x={A∈ |x∈A}.(Y,)another measurable space,let ρ(X, Y,)={∈ |§ be measurable}.∈ρ(X,Y,),we define ()(y)=~(-1)(y),y∈y. Defination 1.T is an index set,f:{0,1}~T→{0,1},then,O~T:( (Y)~x)~T→ (Y)~x is called the operation derived from f if for any { }_(t∈T)∈((Y)~x)~Tand any(x,y)∈X×Y,it holds