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1.
An m-cycle system of order v and index λ, denoted by m-CS(v,λ), is a collection of cycles of length m whose edges partition the edges of λKv. An m-CS(v,λ) is α-resolvable if its cycles can be partitioned into classes such that each point of the design occurs in precisely α cycles in each class. The necessary conditions for the existence of such a design are m|λv(v-1)/2,2|λ(v -1),m|αv,α|λ(v-1)/2. It is shown in this paper that these conditions are also sufficient when m = 4.  相似文献   

2.
The necessary and sufficient conditions for the existence of simple incomplete block design (v, w; 4,2)-IPBDs are determined. As a consequence, the necessary and sufficient conditions for the embeddings of simple two-fold balanced incomplete block designs with block size 4 are also determined.  相似文献   

3.
This paper is concerned with stochastic H_2/H_∞ control problem for Poisson jump-diffusion systems with(x, u, v)-dependent noise, which are driven by Brownian motion and Poisson random jumps. A stochastic bounded real lemma(SBRL for short) for Poisson jump-diffusion systems is firstly established, which stands out on its own as a very interesting theoretical problem. Further, sufficient and necessary conditions for the existence of a state feedback H_2/H_∞ control are given based on four coupled matrix Riccati equations. Finally, a discrete approximation algorithm and an example are presented.  相似文献   

4.
The definitions of θ-ray pattern proposed to establish some new results matrix and θ-ray matrix are firstly on nonsingularity/singularity and convergence of general H-matrices. Then some conditions on the matrix A ∈ C^n×n and nonempty α (n) = {1,2,... ,n} are proposed such that A is an invertible H-matrix if A(α) and A/α are both invertible H-matrices. Furthermore, the important results on Schur complement for general H-matrices are presented to give the different necessary and sufficient conditions for the matrix A E HM and the subset α C (n) such that the Schur complement matrix A/α∈ HI^n-|α| or A/α ∈ Hn-|α|^M or A/α ∈ H^n-| α|^S.  相似文献   

5.
In this paper, several recursive constructions for directed difference family and perfect directed difference family are presented by means of difference matrix and incomplete difference matrix. Finally the necessary and sufficient conditions for the existence of a (gv, g, 3, λ)-directed difference family in Zgv are established. As a consequence, the necessary and sufficient conditions for the existence of a cyclic directed group divisible design with block size three and type gv are obtained.  相似文献   

6.
The mean correcting martingale measure for the stochastic process defined as the exponential of an additive process is constructed. Necessary and sufficient conditions for the existence of mean correcting martingale are also obtained. The investigation of this paper will establish a unified way that is applicable both to the case of L′e vy processes and that of the sums of independent random variables. As an application, we present the necessary and sufficient conditions that the discounted stock price process is a martingale.  相似文献   

7.
In this article we prove that some of the sufficient and necessary optimality conditions obtained by Ginchev, Guerraggio, Luc [Appl. Math., 51, 5-36 (2006)] generalize (strictly) those presented by Guerraggio, Luc [J. Optim. Theory Appl., 109, 615-629 (2001)]. While the former paper shows examples for which the conditions given there are effective but the ones from the latter paper fail, it does not prove that generally the conditions it proposes are stronger. In the present note we complete this comparison with the lacking proof.  相似文献   

8.
Let {Xn,n ≥ 1} be a sequence of identically distributed ρ^--mixing random variables and set Sn =∑i^n=1 Xi,n ≥ 1,the suffcient and necessary conditions for the existence of moments of supn≥1 |Sn/n^1/r|^p(0 〈 r 〈 2,p 〉 0) are given,which are the same as that in the independent case.  相似文献   

9.
The necessary and sufficient conditions for the oscillations of every solution of the nonlinear delay equation x(t) f(x(t l)) g(x([t-k]))=0 are oblained.  相似文献   

10.
Let {Xni} be an array of rowwise negatively associated random variables and Tnk=k∑i=1 i^a Xni for a ≥ -1, Snk =∑|i|≤k Ф(i/nη)1/nη Xni for η∈(0,1],where Ф is some function. The author studies necessary and sufficient conditions of ∞∑n=1 AnP(max 1≤k≤n|Tnk|〉εBn)〈∞ and ∞∑n=1 CnP(max 0≤k≤mn|Snk|〉εDn)〈∞ for all ε 〉 0, where An, Bn, Cn and Dn are some positive constants, mn ∈ N with mn /nη →∞. The results of Lanzinger and Stadtmfiller in 2003 are extended from the i.i.d, case to the case of the negatively associated, not necessarily identically distributed random variables. Also, the result of Pruss in 2003 on independent variables reduces to a special case of the present paper; furthermore, the necessity part of his result is complemented.  相似文献   

11.
We consider the properties on solutions of some q-difference equations of the form ∑ n j=0 aj(z)f(qj z)=an+1(z), where a0(z),..., an+1(z) are meromorphic functions, a0(z)an(z) ≠ 0 and q ∈ C such that 0 〈 |q| ≤ 1. We give estimates on the upper bound for the length of the gap in the power series of entire solutions of (*) when the coefficients a0(z),..., an+1(z) are polynomials and 0 〈 |q| 〈 1. For some special cases, we give estimates of growth of f(z). And we also show that the case 0 〈 |q| 〈 1 is different from the case |q|=1.  相似文献   

12.
In this article, some necessary and sufficient conditions are shown in order that the inequality of the form Ф1(λ)Pu(f^*〉λ)≤Ev (Ф2(C|f∞|)) holds with some constant C 〉 0 independent of martingale f = (fn)n≥0 and λ 〉 0, where Фl and Ф2 are a pair of Young functions, f^*=sup n≥0|fn| adn f∞=lim n→∞ fn a.e.  相似文献   

13.
In this paper both the necessary and sufficient conditions for the existence of the solution of the boundary value problem x=X(t,x,x),px(0)+qx(0)=r,x(∞)=const.and the continuous dependence of the solution on the boundary value are investigated.  相似文献   

14.
刘慧芳  孙道椿 《东北数学》2008,24(6):511-520
In this paper, the uniqueness of algebroidal functions in the unit disc is investigated. Suppose that W(z) and M(z) are v-valued and k-valued algebroidal functions in the unit disc, respectively. Let e^iθ be a b-cluster point of order co or order ρ(x) of the algebroidal function W(z) or M(z). It is shown that if -↑E(aj, W(z)) = -↑E(aj,M(z)) holds in the domain {|z| 〈 1}∩Ω(θ-δ,θ+δ), where b, aj (j = 1,…, 2v + 2k + 1) are complex constants, then W(z) = M(z). The same results are obtained for the case that e^iθ is a Borel point of order co or order ρ(x) of the algebroidal function W(z) or M(z).  相似文献   

15.
This paper gives probabilistic expressions of the minimal and maximal positive solutions of the partial differential equation -1/2△v(x) γ(x)v(x)α = 0 in D, where D is a regular domain in Rd(d ≥ 3) such that its complement Dc is compact, γ(x) is a positive bounded integrable function in D, and 1 < α≤ 2. As an application, some necessary and sufficient conditions for a compact set to be S-polar are presented.  相似文献   

16.
线性时滞系统Liapunov泛函的存在性   总被引:1,自引:0,他引:1  
The delay system x(t)=Ax(t) Bx(t-r)is considered. The necessary and sufficient conditions of the existence of a kind of Liapunov functional for the system are given.  相似文献   

17.
This paper studies a class of multiobjective generalized fractional programming problems, where the numerators of objective functions are the sum of differentiable function and convex function, while the denominators are the difference of differentiable function and convex function. Under the assumption of Calmness Constraint Qualification the Kuhn-Tucker type necessary conditions for efficient solution are given, and the Kuhn-Tucker type sufficient conditions for efficient solution are presented under the assumptions of (F, α, ρ, d)-V-convexity. Subsequently, the optimality conditions for two kinds of duality models are formulated and duality theorems are proved.  相似文献   

18.
This paper establishes some new equalities and inequalities for the null and column spaces of combinations of two projectors P and Q. Some new necessary and sufficient conditions for P ± Q to be invertible are given by the structure of null and column space of some combinations of P and Q. In addition, the inclusion relation of N(P Q + QP) and N(P Q- QP) is discussed and necessary and sufficient conditions for them to be equal are also studied.  相似文献   

19.
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.  相似文献   

20.
The construction of solution for three-order evolution equation xttt=A^3x is skillfully obtained and the semigroup of equation operator is theoretically proved,then the solution for three-order evolution equation xttt+iCx=f is constructed from the appropriate transformation, and the necessary and sufficient conditions of its unitary semigroup are presented.  相似文献   

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